US1990521A - Railway braking apparatus - Google Patents

Description

Feb. 12, 1935. H. L. B ONE 1,990,521 RAILWAY BRAKING APPARATUS Original Filed Jul 9, 19s; 2 Sheets-Sheet 1 i K n m m a E F N n M E0 0 15 n u m a A A Q m, 1 M ll. mv r 7 w. G

Feb. 12, 1935.- H. L BONE I RAILWAY; BRAKING APPARATUS 7 Original Filed July 9, 195k 2 Sheets-Sheet 2 NO R m .fm L. w

Patented Feb. 12, 1935 UNITED QF FH RAILWAY BRAKING APPARATUS Application July 9, 1931,. Serial No. 549,588 Renewed March 26, 1932 i 44 Claims. (01303-21) My invention relates to railway braking apparatus, and has for an object the provision of means for automatically controlling the braking action of a car retarder in accordance with the speed at which a car is approaching the retarder or is passing through the same, and in accordance with the setting of a manually operable speed control lever.

I will describe two forms of braking apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of apparatus embodying my invention. Fig. 2 is a diagrammatic view showing a modified form of the apparatus illustrated in Fig. 1, and also embodying my invention.

Referring first to Fig. l, the reference characters 1 and 1 designate the track rails of a stretch A of railway track over which cars normally move in the direction indicated by the arrow under such conditions that at times it is desirable to control the speed of these cars automatically. For example, the stretch of track here shown might be in a classification yard of the hump type through which cars move under the influence of gravity; It is obvious that in systems of this kind the speed of individual cars or strings of cars will vary through wide limits depending, among other things, upon the speed atwhich they go over the hump, the temperaturethe weight of the car and contents, and the condition of the car as to whether it is a free running car or otherwise.

In order to control the speed of the cars, the stretch of track shown in the drawings is provided with a car retarder designated as a whole by the reference character R, and comprising, in the form here shown, two braking bars 2 and 2 located on opposite sides of, and extending parallel with rail 1, and two similar braking bars 3 and 3 located on opposite sides of, and extending parallel with rail 1 The bars of each pair are so disposed that when they are moved toward the rail they will occupy positions in which they will engage the wheels or other parts of a passing car, thus retarding the passage of the car.

The braking bars 2, 3, 2 and 3 are operated by a fluid pressure motor M, which in the form here shown, comprises a cylinder 4 containing an auxiliary piston 6 which is movablebetween the left-hand end of the cylinder and an intermediate point in the cylinder, and a main piston 5 which is movable between the right-hand end of the cylinder and the auxiliary piston 6. The main piston 5 of motor M is attached to a piston rod '7,

which piston rod, in turn, is operatively connected with the braking bars 2,3, 2 and 3% by means of suitable operating mechanism, one form of which I will now describe.

As here shown, this operating mechanism comprises a three-arm lever, 9 which is pivotally supported in the trackway at 10, and one arm of which is operatively connected with the piston rod '7 in such manner, that this lever will be rtated in a counter-clockwise direction in response to movement of the piston toward the left. The second arm of lever 9 is connected, through a link 11, with a crank 12 which is pivotally supported in the trackway at 13, and the third arm of lever 9 is connected, through a link 14, with a lever 15 which is pivotally supported in the trackway at 16. It will be seen, therefore, that the links 11 and/14 and, the crank 9 constitute atoggle by means of which the cranks 12 and 15 may be swung in the :same directions when the piston5of motor M is operated. The free end-of crank 12 is operatively connected with the braking bars 2 and 3, respectively, by means of resilient connections which include springs 17 and 18,- and, similarly, the free end of crank 15 isoperatively connected with the braking bars 2 and 3 by means of resilient connections which include springs 19 and 20. It will be seen, therefore, that when piston 5 moves toward the left, the cranks 12 and 15 are both swung in a counter-clockwise direction, so that each braking bar is moved toward the associated rails into a braking position in which it engages the side of a wheel of a railway car traversing the rails 1 and l When piston 5 moves toward the right, however, the cranks 12, and 15 are then swung in a clockwise direction, and the braking bars are moved away from the associated rails to their non-braking positions, in which they are out of engagement with the wheels of a passing car. One form of operating mechanism of the type described is disclosed and claimed in my copending application for Letters Patent of the United States, Serial No. 307,895, filed On September 24, 1928, for Railway braking apparatus.

The motor M is controlled by four magnet valves V V V and V As here shown, each valve V comprises a valve stem 21 biased to an upper position by a. spring 22, and provided with 1 an armature 23 and a winding 24. When valve V is energized, valve stem 21 of this valve moves downwardly against the bias exerted by spring 22, and a pipe 26, which communicates with the region of cylinder 4 between the auxiliary piston 6 and the adjacent end of the cylinder, is then connected with a pipe 25 which is supplied with fluid pressure, usually air, from a suitable source not shown in the drawings; When valve V is deenergized, however, valve stem 21 is moved upwardly by spring 22, and pipe 26 is then disconnected from pipe 25. When valve V is energized, valve stem 21 of this valve moves downwardly, thereby connecting pipe 26 with pipe 28, but when valve V is deenergized, pipe 26 is disconnected from pipe 28. When valve V? is energized pipe 29, which communicates with the region of cylinder 4 between the main piston 5 and the adjacent end of the cylinder, is vented to at mosphere through port '70, but when valve V is deenergized, pipe 29 is disconnected from atmosphere, and pipe 28 which is disconnected from port 70 when this valve is energized, is then connected with port 70. When valve V is energized, valve stem 21 of this valve moves downwardly and connects pipe 29 with pipe 25, but when valve-V is deenergized, pipe 29 is disconnected from pipe 25.

The valves V V V and V are controlled by a plurality of circuit controllers S S S S S and S which are controlled in accordance with the position of piston 5; by a pressure responsive device P which is responsive to the pressure in cylinder 4 between the pistons 5 and 6; by the pressure-responsive devices P P and P which are responsive to the pressure in the right-hand end of cylinder 4; and-by a manually operable lever L which, as here shown, is capable of assuming five positions, designated by the reference characters 10 to 10 inclusive. The circuit controllers S S S S, S and the pressure responsive devices P P P and P, and the lever L are similar in allrespects to the corresponding parts described in detail in my Let-- ters Patent of the United States, Patent No. 1,812,193, dated June 30, 1931, forRailway braking apparatus, wherein they are designated by the same reference characters, and itis therefore believed to be unnecessary todescribe them in detail here. Furthermore, a detailed description of the circuits by virtue of which the control of the valves V is effected in accordance with the position of the lever L also believed to be unnecessary in this application because these circuits form no part of my present invention, and are identical with those shown and described in connection with Fig; 10 of my Patent No. 1,812,193 referred to above, with the exception that in my patent, the arm 46* of lever L instead of being connected with battery C over wire 40, back contact 39-39 of a relay D, and Wires 57 and 38 as here shown, is connected directly with battery C over a wire 101; and that the arm 46 of lever ,L instead of being connected with battery B over wire 43, back contact 42 of relay D, and wire 41 as here shown is connected directly with battery B over wire 55. In view of the foregoing, it is thought that, for purposes of the present disclosure, the following brief description of the operation, as a-whole, of the apparatus thus far described will be sufiicient,'it being understood at the outset that, for reasons which will appear as the description proceeds, this operation can take place only when relay D is deene rgized, so that the arms 46 and 46 of lever L are connected with the batteries B and C respectively.

If lever L is moved to its p position, valve V will become energized and will admit fluid at fullline pressure to the right-hand end of cylinder 4 to move piston 5 toward the left and the braking bars toward their braking positions. As soon as piston 5 starts to move toward the left, valve V will become energized and will admit fluid at fullline pressure to the left-hand end of cylinder 4, thus holding auxiliary piston 6 in its projected position in which it is illustrated in the drawings. When the braking bars reach their braking positions, if the pressure in the right-hand end of cylinder 4 then exceeds ten pounds per square inch as is usually the case, valve V will become deenergized and will cut off the supply of fluid pressure to this end of the cylinder, and if the pressure exceeds twenty pounds per square inch, valve V will become energized and will vent fluid from this end of the cylinder to atmosphere until the pressure drops below twenty pounds per square inch. If, however, the pressure in the right-hand end of the cylinder is below ten pounds per square inch when the braking bars reach their brakingpositions, valve V*- will remain energized until the pressure reaches ten pounds per square inch. It will be apparent, therefore, that when lever L occupies its position, piston is held against piston 6 by a pressure of between ten and twenty pounds per square inch. Under these conditions, the toggle of which lever 9 forms a part is not moved to its dead-center position, and the braking action of the'apparatus is therefore cushioned against the volume of air in cylinder 4.

When lever L is moved to its 12 or positions, the operation of the apparatus is similar to that just described with the exception that, in the p position of the lever, when the braking bars reach their braking positions, the valves V and V are automatically operated by the pressure responsive device P to maintain the fluid in the righthand end of cylinder 4 at a pressure of between forty and fifty pounds per square inch, and in the p position of the lever, the valves V and V are automatically operated by the pressure responsive deviceP' to maintain the fluid in the right-hand end of cylinder 4 at a pressureof between seventy and eighty pounds per square inch.

When lever L is moved toits 19 position, valve V becomes energized as before and admits fluid to the right-hand end of cylinder 4 at full-line pressure to move the braking bars to their braking positions. Valve V however, remains deenergized under theseiconditions, and as soon as the piston has started to move toward the left, valve W becomes'energized and vents the lefthand end ofcylinder4 to atmosphere. The pistons 5 andifi therefore move to their extreme lefthand positions under these conditions, thereby moving the toggle mechanism including the lever 9 nearly to its dead-center position. When the piston has moved nearly to its left-hand position, the valves V andV are automatically operated by the pressure responsive device P to maintain the fluid in the right-hand end of cylinder 4 at a pressure of between seventy and eighty pounds per square inch.

If lever L is moved to its 10 position, valve V becomes energized and admits fluid to the lefthand end of cylinder 4 so that the auxiliary piston 6 is moved to its projected position in which it is illustratedin' the drawings. 'Valve V also becomes energized, and since valve V is then energized, fluid pressure is now admitted to the piston toward the rightto 'restore'the braking apparatus to its open or inefiective position in which it is illustrated in the drawings. If the pressure in the region of cylinder 4 between the pistons 5 and 6 exceeds the value at which device P operates during movement of piston 5 toward the right, valve V will become deenergized and will out off the supply of fluid pressure to the region between the auxiliary piston 6 and the adjacent end of the cylinder, and between the pistons 5 and 6; After the pressure has again dropped below the value which caused pressure responsive device P to operate, valve V will again become energized, so that fluid pressure will again be supplied to the region of cylinder 4 between the auxiliary piston 6 and theadjacent end of the cylinder and between the pistons 5 and 6. When piston 5 has reached its right-hand position, valves V V and V all become deenergized, and the parts are then restored to the positions in which they are illustrated in the drawings. When the valves V and V are deenergized, the fluid pressure which has already been supplied to the left-hand end of cylinder 4 is trapped in this end of the cylinder to hold the auxiliary piston 6 in its projected position,

As previously pointed out, the apparatus thus far described only operates in the manner described as long as the retarder release relay D is deenergized. When this relay becomes energized, the opening of its back contact 42 disconnects arm 46 of lever L from battery B, and the opening of its back contact 3939 disconnects arm 46 from battery C. As a result, all of the circuits for controlling the valves V V V and V which are controlled by the lever L are then interrupted, and any of these valves which were previously energized therefore become deenergized. It follows, therefore, that when relay D becomes energized, it renders the control of the valves V V V and V by the lever L ineffective. Furthermore, when this relay becomes energized, the closing of its front contact 39--39 completes an auxiliary circuit for the valve V and the closing of its front contact 44 completes an auxiliary circuit for valve V The auxiliary circuit for valve V passes from battery C through line wire 59, winding 24 of valve V wire 69, contact 36-37 of circuit controller S which circuit controller is normally closed when relay D becomes energized, wire 120, asymmetric unit 121 in its low resistance direction, wire 122, line wire 56 wires 123 and 54, front contact 3939*- of relay D, and wires 57 and 38 back to battery C.- The auxiliary circuit for valve V passes from battery C through line wire 59, winding 24 of valve V wire 62, contact 32-33 of circuit controller S which is normally closed under these conditions, wire 61, contact 45-45 of pressure responsive device P line wire GOKwire 58, front contact 44 of relay D, and wire 38 back to battery C. When these auxiliary circuits are closed, valves V and V both become energized. The energization of valve V vents fluid from the right-hand end of cylinder 4 as will be apparent from an inspection of the drawings, while the energization of valve V admits fluid to the left-hand end of cylinder 4. The fluid admitted to the left-hand end of cylinder 4 under these conditions moves piston 6 to its full projected position thus insuring that the toggle mechanism of which lever 9 forms a part will not occupy its dead-center position, and since the right-hand end of cylinder 4 is vented to atmosphere, it will be seen that piston 5 is then free to move toward the right. As a result, the

braking bars may be forced away from the rails by the wheels of a car under these conditions, so that the braking bars will exert very little, if any, braking force on the car when relay D becomes energized.

In accordance with my invention means are provided for controlling relay D in such manner that this relay will at times automatically become energized when the speed of a car which is traversing the stretch of track shown in the drawings has decreased to a value which depends upon the setting of a manually operable speed control lever S. As here shown, these means comprise a plurality of trackway contacts arranged in several groups, here shown to be three in number, and designated by the reference characters E E and E respectively. In the embodiment illustratedthe group E is located several feet in advance of the retarder, the group E adjacent the entrance end of the retarder, and the group 15 adjacent the leavingend of the retarder. In actual practice, however, the number and locations of the contact groups will be determined by the conditions encountered. The groups E E and E are all alike, and it is believed that an understanding of each may be had from a description of one. Referring to the contact group E for example, this group comprises four contacts 47, 48, 49 and 50, which, as here shown, are arranged to be operated by means of treadles, indicated diagrammatically in the drawings, and designated by the reference characters 47 48 49 and 50% respectively. It will be seen from an inspection of the drawings that in the arrangement illustrated, the treadles 47 and 49 are located adjacent the rail 1 in such positions-that they will be successively engaged and depressed by the flangeof each car wheel which traverses this rail.

The treadle 48 is located adjacent the rail 1 in a position to be engaged and depressed by the flange of every car wheel which traverses this I rail, and is so arranged that this treadle will become depressedat the same instant as the treadle 49*, but will be restored to its normal position before the treadle 49 is restored to its normal position. The treadle 50 is likewise located adjacent the' rail 1 in a position to be engaged and depressed by the flange of every car wheel which runs on therail 1 and is arranged to become depressed while the treadle 48 is depressed, and

to become restored to its normal position at the.

same instant as the treadle 49 is restored to its normal position. The overall length of each contact group is preferably less than the distance between the adjacent wheels on the same truck of a freight car, which distance is usually considered to be five and one-half feet. For purposes of illustration, Iwill assume that treadle 47 is thirty-three inches long, treadle 4.9 thirty inches long, treadle 48 twenty-six inches long, and treadle 50 three inches long. It will be understood that the various contacts are closed or open as the case may be. during the entire time that each car wheel is engaging the associated treadle. For example, contact 49 is open during the entire time that each car Wheel running over rail 1 is moving from one end of the treadle 49 to the other end.

The means for controlling relay D also comprise a plurality of time element relays one of which is provided for each speed at which it is desired to have the cars leave the braking apparatus. In the embodiment illustrated, three time element relays T T and T have been provided, it being thought that this number of relays will be sufiicient for a clear .understanding of my in-' vention. The relays T T and '1 have slowreleasing characteristics and are adjusted to have different release times. For example, for purposes of illustration, I will assume that relay T is adjusted to release its armature in five-tenths seconds after this relay becomes deenergized, relay T in four-tenths seconds, and relay 'I' in three-tenths seconds. It will be understood, however, that in actual practice the release times of these relays Will be selected in accordance with the conditions at the particular location where they are utilized. L r

The manually operablespeed control lever S will usually be located adjacent the lever L in a position where it may be conveniently operated by the same operator who operates the lever L. As here shown, the lever S is capable of assuming four positions, indicated in the drawings by the dotted lines, and designated by the reference characters t 13 t and t Operatively connected with the lever S are three contact arms 51, 52 and 53. The contact arm 51 cooperates with four fixed contacts 51, 51 51 and 51 to close a contact 51-51, 5151 ,,5151 or 5151 according as lever S occupies its 23, 29, or t positions. In similar manner, the arm 52 cooperates with four fixed contacts 52, 52 52 and 52 to close a contact 52-52 52-52 5252 or .5252 according as lever S occupies its t, t t or 15 positions, and the arm 53 cooperates with four fixed contacts 53, 53 53 and 53 to close a contact 5353, 5353 53-53 or 53-53 according as lever S occupies its t t t or 6 position.

When lever S occupies its t or ofi position, relay D is deenergized. Under these conditions, the speed control apparatus is rendered ineffective, and the braking force exerted by-the retarder corresponds at all times to the setting of lever L. When, however, the lever occupies its t position, relay T is rendered effective for 0011 trolling relay D, and relay D will then become cneregized in a mannerto bedescribed hereinafter when the speed of a car which is traversing the stretch of track shown in the drawings de creases below a speed of approximately three miles per hour. Similarly, when lever S occupies its t or t positions, the relays 'I and T are rendered effective for controlling relay D, and relay D will become energized when the speed of a'car traversing the stretch of track shown in the drawings decreases below a speed of approximately four miles per hour and'five an one-half miles per hour, respectively. v Relay T is provided with a circuit which includes a suitable source of current, here shown as a battery F, the contacts 49 of the contact groups E E and E connected in series, the winding of relay T and contact 5353 of lever S. Relay T is also provided with three other circuits each of which includes the battery F, the contact 47 of a difierent one of the contact groups E E and E the winding of relay T and contact 53-53 of lever S. When any one of these circuits is closed, relay T becomes energized. It will be apparent, therefore, that when lever S 00- cupies its 73 position, relay T will normally be energized by virtue of the circuit including the contacts 49 of the contact groups E E and E until a car wheel depresses one of the treadles 49 and opens the associated contact 49 to open this circuit. When this happens, this relay will then become deenergized and will subsequently remain deenergized until the car or cars have moved through a distance which is equal to the length of such treadle49 unless another wheel of a car or cars depresses one of the treadles 47 and closes the associated contact 47 to complete the circuit for, relay T including such contact 47. Since in theembodiment illustrated, relay T requires five-tenths seconds to release, and since the treadles 49 are thirty inches long, it will be apparent that this relay will not open its armature and close its back contact unless the speed of the car is equal to or less than approximately three miles per hour, and unless the position of r the car with respect to all three groups of contacts is such that none of the treadles 47 will become depressed to close the associated contact 47' during the entire'time that a contact 49 is open.

Relay T is provided with four circuits which are similar in all respects to the circuits described hereinbefore for relayv T with the exception that each of these circuits instead of including the winding of relay T and contact 53-53 of lever S include-the winding of relay '1 and contact 5353 of lever S. It will be apparent, therefore, that when lever S is moved to its t position, relay I will normally become energized, and will subsequently remain energized until a car depresses one of the treadles 49 to open the circuit for this relay including the contact 49 controlled by such treadle. If the car is then travelling at a speed of approximately four miles per hour so that the contact 49 is held open for more than four-tenths seconds, and if none of the contacts.

47 becomes closed while the contact 49 is open, relay '1 will" release its armature and close its back contact.-

Relay T is likewise provided with four circuits which are similar to the circuits described for relay T except that each of these circuits include the winding of relay T and contact 53-53 of lever S instead of the winding of relay T and contact 53-53 of leverS. As a result, relay T will be energized unless one of the contacts 49 of the contact-groupsE E and E and all of the contacts 47 remain open for an interval of time of more than three-tenths seconds duration whichfwill at times be the case if and only if the speed of a carwhich is traversing the stretch of track shown in the drawings is equal to or less than approximately five and one-half miles per hour. I

Relay D is providedwith three pick-up circuits one controlled by eachof the relays T T and T The pick-up circuit for relay D controlled by relay T passes from a suitable source of current, such as a battery G, through wire 64, winding of relay D, wires 65 and 66, contact 5151 of lever S, wire 67, back contact 68 of relay T wire 71, and contact "52-52 of lever S back to battery G. The pick-up circuit for relay D controlled by relay T passes from battery G through wire 64, the winding of relay D, wires 65 and 66, contact 51-51 of lever S, wire 72, back contact 73 of relay T wire 74, and contact 52 -52 of lever S back to battery G. The pick-up circuit for relay D controlled 'by relay T passes from battery G through wire 64, winding of relay D, wires 65 and 66, contact 5151 of lever S, wire 75, back contact 76 of relay T wire 77, and contact 5252 of lever S back to battery G. It will be apparent, therefore, that when lever S occupies its 15 position, relay D will become energized provided relay T is then deenergized, and that when lever S occupies its t or 1& positions, relay D will become energized'provided relay '1 or relay T is ,then deenergized.

Relay D is also provided with three stick circuits, each of which includes battery G, the winding of relay D, front contact '78 of relay D, the contacts 50 of the contact groups E E1 and E connected in series, and a different one of the contacts 52-52 52f 2 and 5252 of lever S. Relay D is further provided with three other stick circuits, each of which includes battery G, the winding of relay D, front contact 78 of relay D, the contact 48 of a different one of the contact groups E E and E and a different one of the contacts 52-52 52-52 and 5252 of lever S. It will be apparent, therefore, that when relay D becomes energized, this relay will subsequently remain energized if the contact 50 of each of the contact groups E E and E is then closed, or if any one of the contacts 4'7 of the contact groups E E1 or E is closed.

As shown in the drawings, the parts occupy the positions which they normally occupy when nocar or cars which are to be retarded are approaching the stretch of track shown in the drawings. That is to say, leverL occupies its p or off position, the braking bars occupy their ineffective or non-braking positions, lever S occupies its 1& or off? position, and relays T T and 'I and D are all deenergized.

In explaining the operation of the apparatus as a whole, I will first assume that a car which is moving at a speed of more than three miles per hour is approaching the stretch of trackshown in the drawings, and that it is desired to have the car leave the car retarder at a speed of three miles per hour. The operator therefore first moves lever L toa position which will cause the braking bars to exert sufiicient braking force to slow down the car the necessary amount. That is to say, if the car is a light-weight car, he moves lever L to its 12 position, if the car is a mediumweight car, he moves, lever L to its 11 or p positions, and if the car is a heavy car, he moves lever L to its 23 position. When this lever is moved to any one of these positions, fluid pressure is, of course, admitted to cylinder 4 in the manner previously described to move the braking bars to their effective or braking positions. The operator next moves the speed control lever S to its t position, which is the position corresponding to a leaving speed of three miles per hour. Since contact 53-53 of lever S is then closed, the circuit previously traced for relay T including this contact and the contacts 49 of the contact groups E E and E connected in series becomes closed, and relay T therefore becomes energized and opens its back contact 68. Before back contact 68 opens, however, there is a brief interval of time during which the pick-up circuit for relay D including contacts 52-52 and 51-5l of lever S is closed, and relay D therefore becomes energized. As pointed out hereinbefore, when relay D becomes energized, all of the circuits for the valves V which are controlled by lever L become interrupted, and the auxiliary circuits previously traced for the valves V and V become closed, so that valves V and V are then deenergized, and valves V and V are energized. Under these conditions, the fluid which was previously supplied to the right-hand end of cylinder 4 to move the braking bars to their braking positions is vented to atmosphere and fluid at full-line pressure is supplied to the left-hand end of cylinder 4. Inasmuch, however, as the braking bars are not engaging the wheels of a car under these conditions, and since no fluid is being supplied to the region of cylinder 4 betweenthe pistons 5 and 6, the

braking barsremain in their braking positions.

When the car enters the stretch of track shown in the drawings, and starts to move past the contact group E the forward wheel of the car running on rail lfirst engages the treadle 4'7? and depresses this treadle, thus closing the contact 4'7 associated therewith. The closing of this contact completes the circuit previously traced for relay T including this contact, but since relay T is already energized under these conditions, the condition of this relay remains unchanged. The forward wheel on rail 1 next moves out of engagement with the treadle 4'7 thus permitting contact 47 to open, and immediately thereafter this wheel depresses the treadle 4 9 at the same time as the forward wheel on rail l depresses the treadle 48 The depression of the treadle 49 of course, opens the. associated contact 49, while the depression of the treadle 48 closes the associated contact 48.; The opening of contact 49 under these conditions interrupts the circuit over which relay T was previously energized, and relay T now becomes deenergized. The closing of contact 48 under these conditions completes one of the stick circuits previously traced for relay D, but the remainder of the apparatus is unaffected. The forward wheel on rail 1 next moves out of engagement with treadle 48 and into engagement with treadle 50 thus causing contacts 48 and 50 of conta'ct group E to both become open. The opening of contact 48 interrupts the one stick circuit for relay D which was previously closed at this contact, and the opening of contact 50 interrupts the other stick circuit for relay D which was previously closed at this latter contact. Since the car is travelling at a speed of more than three miles per hour under these conditions, when the two stick circuits for relay D become opened, back contact 68 of relay T will still be open so that the pick-up circuit for relay D will also be open, and relay D will therefore become deenergized. When relay D becomes deenergized, the circuits which were previously closed for valves V and V at front contacts 44 and 3939 of relay D are inter rupted and the control of the valves V by lever L is reestablished. Valve V therefore now becomes energized and admits fluid to the right-hand end of cylinder 4 until the pressure in this end of the cylinder reaches the value which corresponds to the position which lever L then occupies, after which valves V and V automatically operate in the manner previously described to maintain the fluid at the braking pressure for which lever L is set. As soon as the forward wheels of the car move out of engagement with the treadles 49 and 50 of contact group E contacts 49 and 50 of this contact group become closed. The closing of contact 49 reestablishesthe circuit for relay T so that relay T again becomes energized. The closing of contact 50, however, has no effect on the remainder of the apparatus, since relay D is now deenergized so that the stick circuit for relay'D including this contact is now open at front contact '78 of relay D. As the second pair of wheels on the first truck move past the contact group E the treadles 47 48 49 and 50 are depressed and operate the associated contacts in the same manner as these contacts were operated while the first pair of wheels was passing this contact group. Due, however, to the fact that the car is moving at a speed of more than three miles per hour, and since relay D is now deenergized, the operation of these contact under these conditions will have no effect on the remainder of the apparatus as will readily be understood from the foregoing description, and from an inspection of the drawings. As soon as the car enters the braking apparatus, the car starts to slow-down. As long as the speed of the car remains above three miles per hour, the operation ofthe contacts of any one, or any combination of, the contact groups by the wheels will have no effect on the braking apparatus for the reasons pointed out above. When, however, the speed of the car has decreased to such an extent thatits speed is equal to, or less than, three miles per hour, then ifa pair of the wheels of the car moves past one of the contact groups, for example the contact group E while none of the-other wheels of the car are passing any of the other contact groups, the circuitover which relay T was previously energized'vvill be interrupted at contact 49 of this contact group for an interval of time which is longer than the release time of relay T and since the contacts 47 of all of the contact groups are then open, all circuits for relay T will be open, and relay T will therefore release its armature to close its back contact 68. The closing of back contact 68 of relay T will complete the pick-upcircuit for relay D including this contact and relay D will therefore become energized. As soon as the pair of wheels has completely passed the contact group E contacts 49 and 50 of this contact group will become closed. The closing of contact 49 will again energize relay T so that relay T will again pick up, and will interrupt the circuit for relay D which was previously closed at back contact 68 of relay T Since contact 50 of group E is now closed, however, the stick circuit for relay D including the contacts 50 of the contact groups E E and E will be closed, and relay D will therefore remain energized until this stick circuit is again opened at one of the contacts 50, As previously described, when relay D becomes energized, fluid is admitted to the region of cylinder 4 between the auxiliary piston 6 and the left-hand end of the cylinder,and fluid is vented from the righthand end of cylinder 4. Asa result piston is free to move toward the right, and the wheels of the car therefore move the braking bars to an ineffective position thus preventing further retardation of the car as long as relay D remains energized. For reasons whichare believed to be obvious, relay D will remain energized until the car has left the retarder unless the car speeds up to a speed of more than three miles per hour. If this happens, then as soon as a pair of wheels passes one of the contact groups at a speed which does not permit the armature of relay T to drop and depresses the treadle 50 of such group to open the associatedcontact 50, relay D will become deenergized, and will cause the braking bars to again move to their braking positions in the same manner as when the first pair of wheels of the car passed the contact group E It will be seen, therefore, that when lever S occupies its t position, under the above conditions, the car will leave the retarder at a speed of approximately three miles per hour.

I will next assume that with the lever L occupying its p p 3?, or p positions, and with the speed control lever S in its 25 position, a car which is travelling at a speed of more than three miles per hour has moved to the position where a pair of wheels on the first truck is about to pass the contact group E and that the spacing between the trucks on the car is such that a pair of wheels on the second truck will start to move past the contact group E before the pair of wheels on the first truck has completely passed the group E 'Under these conditions, relay D will, of course, be deenergized, and the braking bars will occupy their braking positions. When the wheel which is riding on rail 1, of the pair of wheels of the firsttruck, depresses treadle 4J7 of contact group E the associated contact 47 will become closed and will complete the circuit for relay T including this contact. Since relay T is already energized, however, this has no effect on the apparatus. As soon as the wheel which depressed the treadle 4'7 has moved past this treadle, this treadle will return to its normal position, thus opening the circuit which was previously closed for relay T at this'contact, and immediately thereafter the wheels on this first truck will depress the treadles 48 and 49 of the contact group E simultaneously, thus opening contact 49 of this contact group and closingcontact 48. The opening of contact 49 will deenergize relay T but the closing of contact 48 has no effect on: the remainder of the apparatus under these conditions since relay D is deenergized. Shortly after the treadles 48 and 49 of the contact'group E 'become depressed, the wheel which is riding on rail 1 of the pair of wheels on the rear truck will depress treadle l? of the contact group E The closing of theassociated contacts? will complete a pick-up circuit for relay T and relay T will therefore again become energized. Treadle 47 of contact group E will next return to its normal position, thus opening contact 47, and treadles l8 and i=9 of contact group E will then become depressed, thereby closing contact 48, and opening contact 49 of contact group E Due to the opening of contacts 47 and 49 of contact group E relay T will again become 'deenergized. The closing of contact 48 of contact group E however, does not alTect the remainder of the apparatus since relay D is still deenergized. Shortly after treadles 49 and 50 of contact group E become depressed, the wheel which is riding on rail 1', of the pair of wheels on the first truck, will move but of engagement with treadle 48 of contact group E and into engagement with treadle 50 of this contact group. Asa result, contacts 48 and 50 of. contact group E will both become opened, but since relay D is deenergized, this relay will be unaffected. As soon as the whcels on the first truck have completelypassed the contact group E contacts '49 and 50 will both become closed. Since contact 49 of contact group E is still open, the closing of contact 49 of contact group E under these conditions will not complete the circuit for relay T and it will be apparent, therefore, that the effectiveness of the contact group E for controlling relay T has been cancelled due to the operation of contact group E by the-wheels of the second truck. The wheel of the second truck which is riding on rail I will next move out of engagement with treadle 48 and into engagement with treadle 50 of contact group E thus opening the contacts 48 and 50 of this contact group. Since relay D is still deenergized, however, the opening of these contacts will have no eifect on the apparatus. As soon as the wheels on the second truck have completely passed the contact group E contact 50 will open and contact 49 will become closed. When contact 49 becomes closed, relay T will again become energized. Since the car speed is higher than three miles per hour, relay T will not have been deenergized under these conditions for a. suflicient interval of time to permit its armature to release and close its back contact 68, and it is for this reason that relay D remains deenergized. It will be seen, therefore, from the foregoing, that where two contact groups are being operated at one time, the rear group is the controlling group, and that as long as the speed of the car is above the speed for which the speed control lever is set, the retarder will remain in its braking position, and will continue to slow-down the car.

I will now assume that with the lever L in its 10 10 p or p positions, and with the speed control lever S in its t position, the front pair of wheels of a car which has been slowed down to a speed of less than three miles per hour by the braking apparatus starts to move past the contact group- E and that the spacing between the trucks of the car is such that a pair of wheels on the second truck will start to move past the contact group E before the front pair of wheels has completely passed the contact group E Under these conditions, the operation of the apparatus will be similar to that just described with the following exceptions. Due to the fact that the car is now travelling at a speed of less than three miles per hour, the treadle 49 of the contact group E will be held down and hence the contact 49 controlled thereby will be held open, for an interval of time which is sufficiently long to permit relay T to release its armature and close its back contact 68 before the pair of wheels of the second truck of the car has moved out of engagement with treadles 49 and 50 of contact group E When back contact 68 of relay T becomes closed, relay D will, of course, become energized, and as a result, when the wheels of the second truck do move out of engagement with treadles 49 and 50 of contact group E the subsequent closing of contact 50 will complete the stick circuit for relay D, and relay D will therefore remain energized, until the car departs entirely from the braking apparatus unless the contact 50 of one of the other contact groups is subsequently opened while back contact 68 of relay T is open, which can only happen if the speed of the car again increases to more than three miles per hour. When relay D becomes energized, the braking bars are forced toward their non-braking positions in the manner previously described so that the braking bars exert very little, if any, braking action on the car.

I will next assume that, with lever L in its 10 12 p or 10 positions, and with the speed control lever S in its t position, a car which has been slowed down by the retarder to a speed of three miles per hour and which has caused the retarder to release, subsequently speeds up to a speed of more than three miles per hour just before the forward pair of wheels of the car starts to move past the contact group E and that the spacing between the trucks of the car is such that the rear pair of wheels will start to move past the contact group E while the forward pair is still passing the contact group E Under these conditions, relays D and T will, of course, both be energized. When the wheel on rail 1 of the forward pair of wheels, depresses treadle 47 of contact group E the associated contact 47 will become closed, and will complete the circuit for relay T including this contact, but since relay T is already energized, the operation of this contact will have no effect on the apparatus. As soon as the wheel on rail 1*, of the forward pair of wheels, has passed treadle 47*, this treadle will return to its normal position, and will open the associated contact 47, thus interrupting the circuit for relay T including this contact, and immediately thereafter treadles 48 and 49 of contact group E will become depressed. The resultant closing of contact 48 will complete one of the stick circuits for relay D, but since relay D is already energized, the condition of the apparatus will otherwise be unchanged. The opening of contact 49 of contact group E will deenergize relay T Assuming that the rear pair of wheels now start to move past the contact group E treadle 4J7 of this contact group will become depressed and will close contact 47, which in turn will complete the circuit for relay T including this contact so that relay T will new again become energized, thus rendering contact 49 of contact group E ineffective to further control relay T under these conditions. As soon as the rear pair of wheels has moved past the treadle 47 of contact group E this treadle will return to'itsmormal position, thus opening the associated contact 47, and shortly thereafter the rear pair of wheels will depress the treadles 48 and 49% of contact group E thereby closing contact 48; and opening contact 49, of this contact group. When contacts 47 and 49 are opened under these conditions, all circuits for relay T will be open, and relay T will therefore again become deenergized. The closing of contact 48 of contact group E will completeone of the stick circuits for'relay D. The wheel whichis riding on rail 1*, of the first pair of wheels, will next move out of engagement with treadle 48 of contact group E and into engagement with treadle 50 thus opening contacts 48 and 50 of this contact group. The opening of contacts 48 and 50 will interrupt the stick circuits for relay D which were previously closed at these contacts, but since contacts 48 of contact group E is still closed, relay D will remain energized. As soon as the first pair of wheels has completely passed the contact group E contacts 49 and 50 of this contact group will again become closed. The closing of contact 50 will reestablish the stick circuit for relay D including this contact. The closing of contact 49 under these conditions, however, will have no effect on the apparatus because the circuit for relay T including this contact will still be open at contact 49 of contact group E It will be seen, therefore, that the operation of the contacts of the contact group E by the forward pair of wheels under these conditions has no effect on the apparatus. The wheel which is riding on rail l of the rear pair of wheels, will next move out of engagement with treadle 48" of contact group E and into engagement with treadle 50 thus opening contacts 48 and 50 of this contact group. The opening of contact 48 will interrupt the one stick circuit for relay D which was previously closed at this contact, while the opening of contact 50 will open-the other stick circuit for this relay. Since the car is travelling at a speed of more than three miles per hour, back contact 68 of relay T will still be open when the stick circuits for relay D become opened, and all the circuits for relay D will therefore be open, so that relay D will now become deenergized. When this happens, the braking bars will again be urged to their braking positions to again retard the car as previously described. The braking'bars will now remain in their braking positions unless the car speed again decreases to less than three miles per hour in which event they will become opened in a manner which will be readily understood from the foregoing.-

The operation of the apparatus when the speed control lever is moved to its t or t positions instead of its 1: position, is similar to that just'described with the exception that in these latter positions of the lever, the relays T and T are brought into play for controlling relay D, and relay D will therefore become energized to release the braking apparatus when the speed of the car has decreased to four or five and one-half miles per hour,-respectively. It is believed that the operation of the apparatus under these latter conditions will be readily understood from an inspection of the drawings without describing it in detail.

Referring now to Fig. 2, as here shown, lever S is provided with only two- contact arms 51 and 53. The arm 51 cooperates with the fixed contacts 51, 51 51 and 51 in the manner previously described and also with a contact segment 51 in such manner that the arm 51 will engage the contact segment 51 to close a contact 5l--'-5l when lever S occupies any position but its t position. The arm 53 cooperates with a contact segment 5:3 to close a contact 53--53 in the same manner as the arm 51 cooperates with the segment 5l The relays T T and T as here shown, are connected in parallel ina circuit which includes contact 53---53, of lever S, battery F, and the contacts 49' of the contact groups E E and E connected in series. The relays T T and T are also connected in parallel in three other circuits each of which includes contact 53-453 of lever S, battery F, and the contact 47 of a different one of the contact groups E E and E Relay D, as here shown, is provided with three pick-up circuits each of which is controlled by a different one of the relays T T and T The pick-up circuit for relay D which is controlled by relay T includes battery G, the winding of relay D, back contact 63 of relay T and contact 51-51 of lever S. The pick-up circuit for relay D which is controlled by relay T include-s battery G, the winding of relay D, back contact '73 of relay T and contact 5l-51 of lever S. The pick-up circuit for relay D which is controlled by relay T includes battery G, the winding of relay D, back contact 76 of relay T and contact 51-51 of lever S. It will be apparent, therefore from an inspection of the drawings that the relays T T -or T will be effective for controlling relay D according as lever S occupies its t t or t positions. Relay D is also provided with a stick circuit which includes battery G, the winding of relay D, the contacts 50 of the contact groups E E and E connected in series, front contact 78 of relay D, and contact 5l-5l of lever S. Relay D is further provided with three other stick circuits each of which includes battery G, the Winding of relay D, the contact 43 of a different one of the contact groups E E and E front contact '78 of relay D, and contact 5l5l of lever S. The remainder of the apparatus shown in Fig. 2 is similar to that shown in Fig. l. I

In explaining the operation of the apparatus as a whole when modified as shown in Fig. 2, I will first assume that the operator wishes to slowdown to a speed of three miles per hour a car which is approaching the stretch of track shown in the drawings at a speedof. more than three miles per hour. He therefore first moves lever L to a position corresponding to a braking force which is sufficient to slow-down the car the necessary amount, which, of course, causes the braking bars to move to their braking positions, and he then moves lever S to its t position. The closing of contact 5-353 of lever S completes the circuit for the relays T T and T and all of these relays therefore now become energized. At the same time the closing of contact 5-l51 of lever S momentarily closes the pick-up circuit for relay D including back contact 68 of relay T and relay D therefore becomes energized. When relay D becomes energized, tl1e supply of fluid pressure to the right-hand end of cylinder 4 is cutoff, and the fluid pressure which was previously supplied to this end of the cylinder to-move the braking bars to their braking positions is exhausted to atmosphere, while the left-hand end of cylinder 4 is supplied with fluid at full-line pressure in the, manner previously described to move the auxiliary piston 6 to its full projecting position. Due, however, to the fact that the braking bars are not engaging the wheels of a car under these conditions, the braking, bars remain in their braking positions. As the first pair of wheels of the car move past the contact group Ehtreadle 4'Zeof this contact group first becomes depressed thereby closing the associated contact 47. The closing of thiscontact completes the circuit previously traced for relays T T and T but since these relays are already energized the closing of this contact has no effect on these relays. Treadle 47 next returns to its normal position, and the treadles 48 and 49 become depressed. Contacts 4'7 and 49 therefore become opened and contact 48 becomes closed. Theopening of contact 47 interrupts the circuit for relays T T and T which was previously closed at this contact, and

the opening of contact 49 interrupts the other 1 circuit for the relays T T and T so that these relays all become deenergized. The closing of contact 48 closes one of the stick circuits for relay D, but the. closing of this stick circuit has no effect on the apparatus under these conditions. Treadle 48 next returns to its normal position and treadle 50*- becomes depressed. The resultant opening of contact 48 opens the stick circuit for relay D which was previously closed at this contact and the opening of contact 50 interrupts the other stick circuit for relay D. Since the car is travelling at a speed-of more than three miles per hour, back contact 68 of relay T will still be open when the contact 50 is opened, and'it follows, therefore, that all circuitsfor relay D will now be open, so that relay D will become deenergized. When this happens, the control of the valve V by the lever L is reestablished, and fluid pressure is therefore again admitted to the left-hand end of cylinder 4 to hold the braking bars in their braking positions. Treadles 49 and 50 next return to their normal positions, thus closing contacts 49 and 50. The closing of contact 49 causes the relays T T and T to again become energized. The closing of contact 50, however, has no effect on the. remainder of the apparatus. As the second pair of wheels pass the contact group E the contacts of this contact group are operated in the manner just described, but since the car is still travelling at a speed of more than'three miles per hour, relay T remains energized and relay D therefore remains deenergized, so that the apparatus is unafiected. When the car enters the braking apparatus, the car starts to slow-down,

but as long as the speed of the car remains above passes one of the contact groups, while none of the other pairs of wheels is passing a contact group, the resultant opening of contact 49 will cause relay T to release its armature and close its back contact 68. When this happens, relay D will pick up, thus causing the braking bars to release, and hence preventing further retardation of the car. iter relay D has once been picked up, it will subsequently be held up either by the stick circuit previously traced for this relay including the contacts 50 of the contact groups E E and E connected in series or by its pick-up circuit including back contact 68 of relay T as long as the speed of the car remains below three miles per hour. If, however, the speed of the car again increases to more than three miles per hour, then when the contact 50 of a contact group becomes opened and interrupts the stick'circuit for relay D, the pick-up circuit for relay D will also be open at back contact 68 of relay T and relay D will therefore become deenergized and will subsequently remain deenergized as long as the speed remains above three miles per hour. It will be seen, therefore, that with the apparatus shown in Fig. 2, when lever S occupies its t position, the braking apparatus is automatically operated in accordance with the speed of the car in such manner that the car will leave the apparatus at a speed of approximately three miles per hour.

If the spacing between the trucks of a car is such that more than one group'of contacts are operated at a time while the car is moving through the stretch of track shown in the drawings, the last operated group will be eiiective for controlling the apparatus as will be readily understood from an inspection of the drawings and from the previous description of the apparatus shown in Fig. 1.

If it is desired that the car should leave the braking apparatus at a speed of four or five and one-hali miles per hour instead of at a speed of three mil s per hour, lever S, instead of being moved to its t position will be moved to its 25 or t position, thus rendering the relays 'I or T effective for controlling relay D.

One advantage of railway braking apparatus embodying my invention is that the operator is not required to be able to judge the speed of cars accurately in order to obtain uniform leaving speeds, with the result that a more satisfactory operation is obtained in cases where the angle of vision or weather conditions or inexperience of the operator makes the accurate judgment of speeds difficult.

Another advantage of railway braking apparatus embodying my invention is that due to the fact that the operator is not required to depend on complete manual control to obtain the proper leaving speed of the car, he can control more car retarders than he could if only manual control were provided.

Furthermore, due to the accuracy with which the leaving speed of a car can be controlled in apparatus embodying my invention, the damage to equipment caused by impact between cars which are coupled at too high a speed is eliminated, while sufficient speed is insured to prevent the necessity for shifting engines to complete the coupling of the cars, The elimination of the necessity'ior completing the coupling of cars by shifting engines increases the number of cars that can be handled by a car retarder yard.

While in illustrating my invention, I have shown two separate levers for controlling the braking apparatus, it will be readily understood that inasmuch as it is usually'desirable to have heavily loaded cars leave the retarder at slow speeds ,intermediate loaded cars at intermediate speeds, and lightly loaded cars at high speeds, the two levels may under some conditions be replaced by a single lever.

It will also be readily understood that while I have illustrated my invention in connection with a pneumatically operated retarder, it is not limited to this use, but is equally applicable to any type of power operated retarder.

Although I have herein shown and described only two forms of railway braking apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a pressure responsive device for operating said braking bar, means for controlling the pressure applied to said device, and means including a plurality of time element relays selectively responsive to the speed of the car for at times cutting off the pressure applied to said device.

2. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a pressure responsive device for" operating said braking bar, means controlled in accordance with the position of said braking bar for controlling thev pressure applied to said device, and means re-' sponsive to the speed of the car for at times cutting off the pressure applied to said device.

3. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a pressure responsive device for operating said braking bar, means for controlling the pressure applied to said device, a manually operable lever, and means controlled by said lever for automatically cutting off the pressure applied to said device when the speed of the car has decreased to apredetermined speed.

a. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail.

for engagement with the wheels of a passing car to retard the speed of the car, a pressure responsive device for operating said braking bar,

means for controlling the pressure applied to saiddevice, a manually operable lever having a plu' rality of positions, and means for automatically cutting oil the pressure applied to said device when thespeed of the car has decreased to a value which depends upon the position of said lever.

5. Railway braking apparatus comprising a braking bar located in the trackway, a pressure responsive device for operating said braking bar, manually controlled means for controlling the pressure applied to said device, acontact ar 1 ranged to be operated when a car reaches a first point and tobe restored when the car passes a second point a measured distance from said first point, and means controlled by said contact for at times cutting off the pressure applied to said device.

6. Railway braking apparatus comprising a braking bar located in the trackway, a pressure responsive device for operating said braking'bar, manually controlled means for controlling the pressure applied to said device, a contact arranged to be operated when a car reaches a first point and to be restored when the car passes a second point a measured distance from said first point, and means controlled by said contact for cutting oiT the pressure applied to said device if the speed of the car is below a predetermined speed.

7. Railway braking apparatus comprising a braking bar located in the trackway, a pressure responsive device for operating said braking bar, manually controlled means for controlling the pressure applied to said device, a contact arranged to be operatedwhen a car reaches a first point'and to be restored when the car passes a second point a measured distance from said first point, a relay controlled by said contact, and means controlled by said relay for controlling the pressure applied to said'device.

8. Railway braking apparatus comprising a braking bar located in the trackway, apressure responsive device for operating said braking bar, manually controlled means for controlling the pressure applied to said device, a contact arranged to be operated when a car reaches a first point and to be. restored when the car passes a second point ameasured distancefrom said first point, a relay controlled by said contact, and means controlled by said relay for at times cutting off thepressure applied to said device.

9. Railway braking apparatus comprising a braking bar located in the trackway adjacent a track rail, a pressure responsive device ,for moving. saidbraking bar into position to engage a part of a' car to retard the speed of the car, manually controlled means for supplying pressure to said device, a firstlcontact'arranged to be operated when a car reaches one point and to be restored when the car reaches a second point a measured distance from said first point, a. sec- 0nd contact arranged'to be operated'when the carreaches a third point a short distance in rear of saidsecond point and to be restored when said car reaches said second point, a first relay con trolledby said first contact, a second relay controlled by saidfirst relay and bysaid second contact, and means controlled by said second relay for at times cutting off the supply of pressure to said device.

10. Railway braking apparatus comprising a braking bar located in the trackway adjacent a track rail, a pressure responsive device for moving, said braking bar into position to engage a part of a car to retard the speed of the car,

manually controlled means for supplying pres sure to said device, a first contact arranged to be operated when a car reaches one point and to be restored when the car reaches a second point a measured distance from said first point, a second contact arranged to be operated when the car reaches a thirdpoint a short distance in rear of said second point and to be restored when said car reaches said second point, a first relay controlled by said first contact, a second.re1ay,.a pick-up circuit for said. second relaycontrolled by. said first relay, 9. stick circuiti or said second relay controlled-by said second; contact, and means controlledby said second-relay for attimes cutting off the supply of pressure to said device.

11. Railway braking apparatus comprising; a braking bar located in the trackway adjacent a track rail, a pressure responsive deviceformoving said braking bar into position toyengage a part of a car, a winding, manu ally controlled means effective for supplying pressure to said device when said winding is deenergized butnoti when said winding is ;ener;gized, 'a contact ar-; ranged to be operated when acar reaches :one point and tobe restoredwhen thecar passes a second point a measured distance fromsaid first point, and means for energizing said Winding controlled by said contact.

12. Railway brakingapparatuscomprising a braking bar located in the trackway adjacent a track rail, a pressure responsive deviceformoving said braking bar into position to engage a part of a car, a winding, manually controlled means-effective for supplying pressure to said device when said winding is deenergized but not when said winding is energized, a contact ar ranged to be operated when a car reaches one point and to be restored when the car passes a second point a measured distance from said first point, and slow acting means for energizing said winding controlled by said contact.

13. Railway braking apparatus comprising a brakingbar located in the trackway adjacent a track rail, a pressure responsive device for moving said braking bar into position to engage a part of a car, a winding, manually controlled means eifective .for supplying pressure to said device when said winding is deenergized but notranged to be operated when a car reaches one point and to be restored when the car passes a second point a measured distance from said first point, and means for energizing said winding if said contact is held in its operated condition for more than a predetermined time interval.

14. Railway braking apparatus comprising a braking bar. located in the trackway adjacent a track rail, a pressure responsive device for moving said braking bar into position to engage a part of a car, a winding, manually controlled means efiective for supplying pressure to said device when said winding is deenergized but not when said winding is energized, a contact arranged to be operated when a car reaches one point. and to be restored when the car passes a second point ameasured distance from said first point, a manually operable lever capable of assuming a plurality of positions, and means con trolled by said contact for energizing said winding if said contact is held in its operated conditionfor a time interval which depends upon the position of said lever.

15. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressuremotor forinoving said braking bar toward the track rail, manually controlled means for, supplying fiuid to said fluid pressure motor at diiierent pressures to control the pressure at which .said braking bar is urged against the wheels of apassing car, and means including a plurality of time element relays selectively responsive to the speed of the car for controlling the pressure of the fluid which is supplied to said fluid pressure motor.

16. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, manually controlled means for supplying fluid to said fluid pressure motor at different pressures to control the pressure at which said braking bar is urged against the wheels of a passing car, and means responsive to the speed of the car for automatically controlling independently of said manually controlled means the pressure of the fluid which is supplied to said fluid pressure motor.

17. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, manually controlled means for supplying said fluid pressure motor with fluid at different pressures to control the pressure at which said braking bar is urged against the wheels of a passing car, and means for automatically decreasing the pressure of the fluid in said cylinder if the speed of the car decreases below a predetermined value.

18. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, a manually operable lever having a plurality of diflerent positions, means for supplying said fluid pressure motor with fluid at different pressures in accordance with the different positions of said lever to control the pressure at which said braking bar is urged against the wheels of a passing car, and means eflective if the speed of said car decreases below a predetermined value for cutting ofl the supply of fluid to said fluid pressure motor and for venting the fluid which has already been supplied to said motor to atmosphere.

19. Railway brakinr apparatus comprising a braking oar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressure .motor for moving said braking bar toward the ,ing car, a speed control lever, and means controlled by said speed control lever and by the speed of the car for at times controlling the pressure of the fluid which is supplied to said fluid pressure motor independently of said manually controlled means.

20. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the rails of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, manually controlled means for supplying said fluid pressure motor with fluid at different pressures to control the pressure at which said braldng bar is urged against the wheels of a passing car, a speed control lever, and means controlled by said speed control lever and by the speed of the car for at times rendering said manually controlled means ineflective. A

21. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagementwith the wheels of a passing car to retard the speed or" the car, a fluid pressure motor for moving said braking bar toward the track rail, manually controlled means for supplying said fluid pressure motor with fluid at diiierent pressures to control the pressure at which said braking bar is urged against the wheels of a passing car, a speed control lever capable of assuming a pluralityof positions, and means for cutting off the supply of fluid to said-fluid pressure motor if the speed of said car decreases below a value which depends upon the position of said speed control lever.

22. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, manually controlled means for supplying said fluid pressure motor with fluid at different pressures to control the pressure at which said braking bar is urged against the wheels of a passing car, a time element relay having a predetermined release time, means for normally energizing said relay, means for at times deenergizing said relay for a time interval which depends upon the speed of the car, and means controlled by said relay for controlling the pressure or" the fluid in said fluid pressure motor independently of said manually controlled means.

23. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, a relay, means controlled in part by the contacts of said relay and effective when said relay is deenergized for supplying said fluid pressure motor with fluid at different pressures to control the pressure at which said braking bar is urged against the Wheels of a passing car, and means controlled in accordance with the speed of the car for at times energizing said relay.

24. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of. the car, a fluid pressure motor for moving said braking bar toward the track rail, a relay, means eflective when said relay is deenergized for supplying said fluid pressure motor with fluid at different pressures to control the pressure at which said braking bar is urged against the wheels of a passing car, and means controlled in accordance with the speed of thecar for at times energizing said relay when the speed of the car has decreased to a predetermined value.

25. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheels of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, a relay, means effective when said relay is deenergized for supplying said fluid pressure motor with fluid at diiierent pressures to control the pressure at which said braking bar is urged against the wheels or" a passing car, a manually operable speed control lever, and means controlled by said lever and by the car for energizing said relay when the speed of the car has decreased to a predetermined value.

26. Railway braking apparatus comprising a braking bar extending parallel with a track rail and adapted to be at times moved toward the rail for engagement with the wheel of a passing car to retard the speed of the car, a fluid pressure motor for moving said braking bar toward the track rail, a relay, means effective when said relay is deenergized for supplying said fluid pressure motor with fluid at difierent pressures to control the pressure at which said'bralring bar is urged against the wheels of a passing means effective when said relay is energized for cutting oii the supply of fluid pressure to said motor and for venting the fiuid pressure which was previously motor for moving said braking bar toward the.

track rail, a relay, means'controlled in part bythe contacts of said relay and efiective when saidrelay is deenergized for supplying said fluid pressure motor with fluid at different pressures to control the pressure at which said braking bar is urged against the wheels'of a passing car, a manually operable lever, and means controlled in accordance with the speed of the car and by said lever for at times energizing said relay.

28. In combination with a stretch of'railway track, a braking bar extending parallel with one of the track rails of the stretch and adapted to be moved toward and away from said track rail into braking and non-braking positions, a fluid pressure motor, a first manually operable levercapable of assuming several positions, a relay, means effective when said relay is deenergized for supplying said fluid pressure motors with fluid at different pressures in accordance with the difierent positions of said first lever to cause said braking bar to exert diiferent braking forces, a plurality of contacts located in the trackway along said stretch and adapted to be operated by the car as the car traverses the stretch, a second manually controlled lever capable of assuming several positions, and means controlled by said levers and by said contacts for energizing said relay when the speed of the car has decreased to a speed which depends upon the position of said second manually controlled lever.

29. In combination with a stretch of railway track, a braking bar extending parallel with one of the track rails of the stretch and adapted to be moved toward and away from said track rail into braking and non-braking positions, a fluid pressure motor, a first manually operable lever capable of assuming several positions, a relay, means effective when said relay is deenergized for supplying said fluid pressure motor with fluid at different pressures in accordance with the means controlled in part by said contacts for energizing said relay when the speed of the car has decreased below a predetermined speedf 3D. In combination with a stretch of railway track, a braking bar located in the trackway, a cylinder, a first piston movable in said cylinder between one end of the cylinder and an intermediate point in the cylinder, 2, second piston operatively connected with said braking bar and movable in said cylinder between the other end of the cylinder and said first piston, a first magnet valvearranged when energized to admit fluid pressure to said cylinder between said first piston and the adjacent end of the cylinder, a second magnet valve, means efiective when said first and second magnet valves are both energized for admitting fluid pressure to said cylinder between said first and second pistons, a third magnet valve arranged when energized to vent the region of said cylinder between said secondpiston and the adjacent end of the cylinder to-atmosphere, a fourth magnet valve arranged when energized to admit fiuid pressure to said cylinder between said second piston and the adjacent end of the cylinder; means for exhausting fluid pressure from the region between said piston when said third valve is deenergized and from the region between said first piston and the adjacent end of the cylinder when said second valve is energized and said third valve is deenergized, a manually operable lever capable of assuming a plurality of positions, a relay, means controlled by said lever and effective when and only when said relay is deenergized for selectively energizing said valves, means elfective when said relay is energized for energizing said first and third valves, and means for energizing said relay when the speed of a car traversing said stretch exceeds a predetermined speed.

31. In combination with a stretch of railway track, a braking bar located in the trackway, a cylinder, a first piston movable in said cylinder between one end of the cylinder and an intermediate point, in the cylinder, a second piston operativelyiconnected with said braking bar and movable in said cylinder between the other end of the cylinder and said first piston, a first magnet valve arranged when energized to admit fluid pressure to said cylinder between said first piston and the adjacent end of the cylinder, a second magnet valve, means efiective when said first and second magnet valves are both energized for admitting fluid pressure .to said cylin der between said first and second pistons, a third magnet valve arranged when energized to vent the region of said cylinder between said second piston and the adjacent end of the cylinder to atmosphere, a fourth magnet valve arranged when energized to admit fluid pressure to said cylinder between said second piston and the adjacent end of the cylinder; means for exhausting fluid pressure from the region between said pistons when said third valve is deenergized and from the region between said first piston and the adjacent end of the cylinder when said second valve is energized and said third valve is deenergized, a manually operable lever capable of assuming a plurality of positions,'a; relay, means controlled by said lever and eifective when and only when said relay is deenergized for selectively energizing said valves, a slow releasing relay, means controlled by said slow releasing relay for controlling said first relay, and means for controlling said slow releasing relay in accordance with the speed of a car traversing said stretch.

32. In combination with a stretch of railway track, a railway braking bar located in the trackway, a cylinder, a first piston movable in said cylinder between one end of the cylinder and an intermediate point in the cylinder, a second piston operatively connected with said braking bar and movablein said cylinder between the other end of the cylinder and said first piston, a first magnet valve arranged when energized to admit fiuid pressure to said cylinder between said first piston and the adjacent end of the cylinder, a second magnet valve, means effective when said first and second magnet valves are both energized for admitting fluid pressure to said cylinder between said first and second pistons, a third magnet valve arranged when energized to vent the region of said cylinder between said second piston and the adjacent end of the cylinder to atmosphere, a fourth magnet valve arranged when energized to admit fluid pressure to said cylinder between said second piston and the adjacent end of the cylinder; means for exhausting fluid pressure from the region between said pistons when said third valve is deenergized and from the region between said first piston and the adjacent end of the cylinder when said second valve isenergized and said third valve is deenergized, a manually operable lever capable of assuming a plurality of positions, a relay, means controlled by said lever and effective when and only when said relay is deenergized for selectively energizing said valves, a slow releasing relay, means controlled by said slow releasing relay for controlling said first relay, a speed control lever capable of assuming different positions, and means controlled by a car traversing said stretch for operating said slow releasing relay when the speed of the car has decreased below a value which depends upon the position of said speed control lever.

33. In combination with a stretch of railway track, a railway braking bar located in the trackway, a cylinder, a first pistonmovable in said cylinder between one end of the cylinder and intermediate point in the cylinder, a second piston operatively connected with said braking bar and movable in said cylinder between the other end of the cylinder and said first piston, a first magnet valve arranged when energized to admit fluid pressure to said cylinder between said first piston and the adjacent end or" the cylindea second magnet valve, means efiective when said first and second magnet valves are both energized for admitting fiuid pressure to said cylinder between said first and second pistons, a third magnet valve arranged when energized to vent the region of said cylinder between said second piston and the adjacent end of the cylinder to atmosphere, a fourth magnet valve arranged when energized to admit fiuid pressure to said cylinder between said second piston and the adjacent end of the cylinder; means for exhausting fiuid pressure from the region between said pistons when said third valve is deenergized and from the region between said first piston and the adjacent end of the cylinder when said second valve is energized and said third valve is deenergized, a manually operable lever capable of assuming a plurality of positions, a relay, means controlled by said lever and effective when and only when said relay is deenergized for selectively energizing said valves, a slow releasing relay, means controlled by said slow releasing relay for controlling said first relay, a plurality of trackway contacts arranged to be operated in a predetermined order by each pair of wheels on a car traversing said stretch, and

means controlled by said contacts for controlling said slow releasing relay.

34. Railway braking apparatus comprising a braking bar located in the trackway adjacent a said second contact, and means controlled by said I second relay for controlling said braking bar.

35. Railway braking apparatus comprising a braking bar located in the trackway adjacent a track rail, a first contact arranged to be operated when a car reaches a first point and to be restored when the car reaches a second point a measured.

distance from said first point, a second contact arranged to be operated when the car reaches a third point ashort distance in rear of said second point and to be restored when said car reaches said second point; a first relay controlled by said first contact, a second relay, a pickup circuit for said second relay including a contact of said first relay, a stick circuit for said second relay including its own front contact and said second contact, and means controlled by said second relay for controlling said braking bar.

38. Railway braking apparatus. comprising a braking bar locatedin' the trackway adjacent a track rail, a first contact arranged to be operated when a car reaches a first point and to be restored when the car reaches a second point a measured distance from said first point, a second contact arranged to be operated when the car passes a third point a short distance'in advance of said second point and to be restored when the car passes a fourth point a measured distance in advance of said third point, a third contact arranged to be operated when the car passes said third point and to be restored when the car passes a fifth point intermediate said third and fourth points, a fourth contact arranged to be operated when the car passes a sixth point intermediate said fourth and fifth points and to be restored when the car passes said fourth point, a.

first relay, a first circuit for said first relay including said first contact, a second circuit for said first relay including said second contact, a second relay, a pick-up circuit for said second relay including a contact of said first relay, a first stick circuit for said second relay including its own front contact and said third contact, a second stick circuit for said second relay including its own front contact and said fourth contact, and means controlled by said second relay for controlling said braking bar.

37. Railway braking apparatus comprising a braking bar located in the trackway adjacent a track rail; a plurality of contact groups located at spaced intervals along the trackway, each said contact group comprising a first normally open contact arranged to become closed each time a car wheel passes a first fixed point along the trackway and to remain closed until the car wheel passes a second point a measured distance in advance of said first point, a first normally closed contact arranged to become opened each time a car wheel passes a' third point a short distance in\ advance of saidsecond point and to remainclosed until the car wheel passes a fourth point a measured distance in advance of said and to remain open until the car wheel passes said fourth point; a slow releasing relay, a first circuit for said slow releasing relay including the first normally closed contact'of each contact group, a plurality of other circuits for said slow releasing relay each including the first normally open contact of adifferent one of said contact groups, 'a second'relay, a pick-up circuit for said second relay including a back contact of said first relay, a first stick circuit for said second relayincluding its ovm front contact and the second normally'closed contact of each contact group, a plurality of other stick circuits for said second relay eachincluding a front contact of said second relay'and the-second normally open contact of a different one of said contact groups, and means controlled by said second relay for controlling said braking bar.

38. In combination, a stretch of railway track, a car retarder associated with said stretch, power operated means for controlling the brakingaction of said carretarder', manually controlled means for controlling said power operated means, a relay, means controlled by said relay for at times rendering said manually controlled means ineffective for controlling said power operated meanspand means controlled by a car traversing said stretch for controlling said relay.

39. In combination, a stretch of railway track, a car retarder associated with said stretch, a relay, means controlled by said relay for controlling the braking action of said car retarder,

manually operable lever capable of assuming a plurality of positions, and means controlled by a car traversing said stretch for' operating said relay when the spced of the car is less than a speed which depends upon the position of said lever.

40. In combination, a stretch of railway track,

a car retarder associated with said stretch, a relay, manually controlled power operated means effective when and only when said relay is desaid relay when the speed of the car decreasesbelow a speed which depends upon the position of said speed control lever.

41 In combination, a stretch of railway track, a car retarder associated with said stretch, a relay, manually controlled power operated means efiective whenand only when said relay is deenergized, for causing said car retarder to exert different braking forces, a speed control lever having a plurality of positions, and means controlled by a car in said stretch for energizing sai-d'relay when the speed of the car decreases below a predetermined speed which depends upon the position of said speed control lever and for again deenergizing said relay if the speed of the car again increases beyond sai-d predetermined speed.

42. In combination, a stretch of railway track, a car retarder associated with said stretch, manually controlled power operated means for causing said car retarder to exert different braking forces, a first relay, means eilective when said first relay becomes operated for cutting ofi the supply of power to said power operated means, a manually operable speed control lever having a plurality of positions, a plurality of timing relays having different operating characteristics, a plurality of circuits for each of said timing relays, means controlled by said speed control lever for selectively controlling said circuits in such manner'that the circuits for a different one of said timing relays arerendered effectivefor controlling such timing relay in each diiierent position of said lever, means controlled by a car traversing said stretch for controlling said circuits, and means controlled by said timing relays for controlling said first relay.

43. In combination, a stretch of railway track, a braking bar located in the tracliway adjacent a track rail, means for moving said braking bar toward or away from the rail into a braking or a non-braking position according as the speed of a car is above or below a predetermined speed while the car is traversing any one of a plurality of fixed distances located along said stretch, and manually controlled means for controlling the braking force that said braking bar will exert when it is moved to its braking position.

44. In combination, a stretch of railway track, a braking bar located in the trackway adjacent .a track rail, means for moving said braking bar toward or away from the rail into a braking or a hon-braking position according as the speed of the car is above or below 'a selected one of a plurality of predetermined speeds while the car is traversing any one of a plurality of fixed distances located along said stretch, and'manuall'y controlled means for controlling the braking force that said braking bar will exert. whenit is moved to its braking position.

HERBERT L. BONE.

Images