US635988A - Brake-slack take-up. - Google Patents

Description

Patented out. 3|, |899.

V 2 Sheets-Sheet 2,

ion ledy May 5, 1898.)

J. C.` WANDS. BRAKE SLACK TAKE-UP.

(Applicat .l llll IU VIIIIL ('No Model.)

UNITED STATES PATENT EErcE.

JOI-INC. WANDS, OF ST. LOUIS, MISSOURI.

BRAKE-SLAC'K TAKE-UP.

SPECIFICATION forming' part of Letters Patent No. 635,988, dated October 31, 1899.

Application tiled May 5, 1898. Serial No. 679,845. (No model.)

To all whom, t may concern:

Be itv known that I, J oHN O. WANDs, a citi; Zen of the United States, residing at St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Brake- Slack Take-Ups and I hereby declare the following to be a full, clear, and exact description of the saine, reference being had to the accompanying drawings, in which-- Figure l is a side elevation of devices embodying myinvention shown in connection with a freight-brake cylinder, the cylinder and tubular piston-rod being in section. Fig. 2 is a plan view of devices embodying myinvention shown in connection with a brakecylinder and the lioating levers of a brakerigging, parts of the cylinder and brakelevers broken away. Fig. 3 is an enlarged side elevation of devices embodying my invention as shown in Fig. l, the lever-block and the push-bar lug and lever-blocking for the spring-bar being in section and portions of the carry-iron and distance-stop being broken off. Fig. 4 is a horizontal sec-l tion of the devices shown in Fig. 3, taken on the line 4 4, Fig. 3, looking in the direction of the arrows, showing a plan view of the spring-bar. Fig. 5 is a sectional view of the devices shown in Fig. 3, taken on the line 5 5, looking in the direction of the arrows, showing an end elevation of the lever-block, a portion of one of the floating levers, and crosssectonal views of the push-bar casting and the spring-bar.

Like symbols refer to like parts Wherever they occur.

My invention relates to the construction of that class of devices especially designed for eliminating the slack from the brake-rigging of a brake system whether the same be due to shoe-wear, stretching of the brake-rigging, or from other well-known causes, and in so far as my present invention is particularly adapted to freight-car air-brakes I have chosen tov illustrate itin connection therewith, but'wit'hout any intention of limiting its use or my claims to such a combination. Heretofore, so-

far as I am aware, in this class of slack takeups the common practice has been to depend on the inward movement of the push-bar resulting from the gravitation of the brakes when released to take up the slack, which movement being varied and uncertain resulted in a corresponding uncertainty in the operation of the take up mechanism. To overcome this objection and obtain a positive operation of the take-up devices independent of any movement of the brakes is one object of my present invention, and this I accomplish by interposing a spring or equivalent resilient medium between the push-bar and the loatin g lever or the lever-block, whereby the reaction of the spring positively actuates the push-bar and lever or lever-block whenever-the push-bar has exceeded its predetermined or normal travel in applying the brakes, and such a combination or its equivalent embodies one feature of my invention.

As is now understood by those acquainted with air-brake practice, there is an appreciable difference(sometimes two or three inches) between the standing and running travel of the air-brake piston, and to effectively elimi-v nate the slack from the brake-rigging system the excessive travel of the piston or push-bar should be measured while running. To accomplish this and automatically eliminate the slack is a second object of my invention, for which purpose I provide a spring-bar actuated from or carried by the push-bar, a distance-stop, and'means whereby the springbar may act upon the floating lever or leverblock, and such a combination or its equivalent embodies a second feature of my invention.

Under certain conditions-as, for instance, inv shunting or making a runningswitchthe brakes are applied by hand in the ordinary manner instead of by the airbrakes, and under said conditions as at present constructed the operative relation of the slack-take-up mechanism with reference to the air-brake piston and push-bar is liable to be so disturbed as to render the take-up mechanism subsequently inoperative, and especially is this the case where a loose push-bar is used, as inthe case of freight-car air-brake cylinders. To overcome said objection is a third object Iv have in view, and to accomplish the same I combine with a iioating lever or lever-block and a push-bar means for locking said parts together or causing them to IOO move in unison when the brakes are applied by hand, whereby the fixed relations of the push-bar and take-up mechanism are maintained at all times, and such a combination or its equivalent embodies a third feature of my invention.

A further object which I have in view is to cause the setting of the brakes by hand to so actuate the slack-take-up mechanism that on the release of the brakes slack, if present, shall be eliminated from the system, and this I effect by combining with the hand-brake rod and the ioating lever or lever-block a distance-stop, a spring-bar, and means for actuating the lever or lever-block from the spring-bar, and such a combination or its equivalent embodies a fourth feature of my invention.

There are other (minor) features of invention, all as will hereinafter more fully appear.

I will now proceed to describe my invention more fully, so that others skilled in the art to which it appertains may apply the same.

In the drawings, A indicates an air-brake cylinder, I3 the piston, C the tubular pistonrod, D the pistou-spring, and E the push-bar, of the usual or any approved form of airbrake for freight-cars.

F F' indicate the iioating levers of a brakerigging, having the usual connections with the rods leading to the brakes, as well as with each other, by means of the tie-rod f, and with the hand-brake by means of the handbrake rod f.

The push-bar E of the air-brake may be extended sufliciently to constitute the rack for the lever-block, but is preferably shortened and supplemented by a push-bar casting l, securely attached thereto and provided on its upper surface with a rack, with which engages a dog 2 on the slide or lever-block 2, and on its under surface with a perforated lug l, through which passes the spring-bar 3.

In order to accommodate the height and angles of the levers of brake-rigging now in use, I prefer to drop the push-bar casting 1, and this also brings thc center of the main lever F on a line with the center of the push-bar E. The free end of push-bar casting 1 passes loosely through a carry-iron 4, the lower end of which constitutes a distance-stop for the spring-bar 3 and has an inclined inwardlyprojecting lug 5 for lifting the spring-bar at the end of its outward travel and an overhang 5 above the incline to limit the rise of the spring-bar 3 and hold it thereafter.

2 indicates a lever-block arranged to be carried by and slide on the push-bar casting l, said lever-block having a pawl or dog 2,whieh engages the rack on the upper surface of the push-bar casting and prevents the movement of the slide backward or toward the cylinder A. Vith this slide or lever-block 2 the main iioating lever F is pivotally connected in any suitable manner; but preferably, forconvenience in fitting up the parts, the lever-block 2 is provided with an open slot or jaw 2",which permits of the introduction of the lever F from the front, and with a bolt 2C,which forms the pivotal connection between the lever and the lever-block.

Upon its under surface and in line with perforated lug la of the push-bar casting the lever-block 2 is provided with a slotted lug 2d for the passage of the spring-bar 3, and on said slotted lug 2d is pivoted a gravity-dog 20, adapted to engage a rack on the upper face of the spring-bar 3, while the bottom of the slot is shaped to form or constitute a fixed dog 2f, (see Fig. 3,) adapted to engage arack on the under side of spring-bar 3.

3 indicates the spring-bar, supported loosely in the perforated lugs ln and 2d, pendent from the push-bar casting and lever-block, so as to both move therewith and independently thereof, and said spring-bar is at its forward end provided on its upper and under surfaces with reversely-arran ged racks, the one adapted for the engagement of the gravity-dog 2c and the other adapted to engage the fixed dog 2f.

3n indicates a collar or button on one end of the spring-bar 3,whicl1 restricts the forward movement of the bar and prevents its escape from the perforated lug l, and 3'b is a collar on the spring-bar between the lugs ln and 2, which forms one seat of a spiral spring G,which encircles the spring-bar, the other seat of said Spring G being the face of lug l, so that the spring-bar 3 is normally held in the forward position, as indicated in Fig. l of the drawings. Said spring-bar 3 is the means whereby any excessive travel of the piston, due to lost motion in the brake-rigging, is measured While running and in applying the brakes and by which the lost motion is eliminated from the system when the brakes are released. For this purpose it is so set (see Fig. l) and the distance-stop 4 and 5 is so located with relation thereto that the devices remain inoperative so long as the travel of the piston (or movement of the lever-block) is normal, but when the same is excessive the forward end of spring-bar 3 engages the distance-stop 5 and the take-up devices are brought into operation.

The construction and combination of the devices being substantially such as hereinbefore set forth, their operation will be as follows: The air is admitted to the cylinder A in the usual manner, the piston-head B and hollow stem C move outward, forcing the push-bar E and its continuation-the pusl1- bar casting l-in the same direction, and the push-bar casting, through the medium of dog 2, carries with it the lever-block 2 and main lever F', thus applying the brakes. So

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long as the travel of the air-brake piston is normal-that is to say, does not exceed the predetermined travel required to set the brakes when there is no slack or lost motion in the system-the spring-bar 3 will reciprocate with the push-bar casting and leverblock without coming in Contact with the distance-stop 5, and the slack-take-up mechanism will remain inoperative. As soon, however, as any lost motion or slack occurs in the system from shoe-wear or other cause and the air-brake piston exceeds its normal or predetermined travel in applying the brakes the forward end of spring-bar 3 will come in contact with distance-stop 5, up which it will ride until its motion is arrested, and said lifting of the spring-bar 3 will disengage the rack on its under surface from the fixed dog 2f on the lug 2d of lever-block 2. The movement of the spring-bar 3 being thus arrested, while that of the push-bar casting l and lever-block 2 continues to the extent required to apply the brakes, the spring 6 is compressed, and the gravity-dog 2,pivoted on lug 2d of the lever-block, traverses the rack on the upper surface of the spring-bar 3, measuring the excessive travel of the air-brake piston while running, and when the movement of the lever-block ceases by reason of the set of the brakes said dog 2e (see Fig. 3) drops into the notch corresponding with the distance measured or excessive travel of the piston. On the release of the brakes the forward end of spring-bar 3 will escape from inclined lug or distance-stop 5, allowing the rack on the under face of the spring-bar to again engage fixed dog 2f, and the reaction of spring G will force the push-bar and pushbar casting back to its original position and the lever-block 2 forward a distance equal to that measured by the spring-bar or sufficient to eliminate the slack from the system, the dog 2 of the lever-block 2 meanwhile traversing the rack on the upper surface of the pushbar casting and rengaging at the limit of its movement, so that on the next outward movement of the piston-rod in applying the brakes the lever-block will move with the push-bar casting, and the travel of both will be normal or only the predetermined distance required to apply the brakes where no lost motion or slack exists.

In case the brakes are applied by hand, as in shunting or making a running-switch, the power applied through the hand-brake rod f', acting on the main lever F, thence on the lever-block 2, thence on the spring-bar 3, and thence on the push-bar casting l, will cause said parts to retain their fixed relations and move in unison, in like manner returning to their original position when the brakes are released, the same as if operated by means of the push-bar of the brake-cylinder, and, furthermore, if any slack exists in the system when the brakes are thus applied by hand the operation of the lspring-bar 3 (its arrest by the distance-stop, the.) will be the same as hereinbefore set forth, and the slack will be eliminated upon the release of the hand-brake.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

l. In a brake-slack take-up, the combination with a push-bar, of a brake-lever movably connected therewith, and an interposed resilient device which yields to measure the slack on the outward movement of the pushbar and reacts to eliminate the slack upon the instroke of the push-bar, substantially as and for the purposes specified.

2. In a brake-slack take-up, the combination with a push-bar, and a brake-lever movable thereon, of an interposed spring adapted to be compressed by the excessive outward movement of the push-bar to measure the slack and byits reaction to eliminate the slack upon the instroke of the push-bar; substantially as and for the purposes specified.

3. In a brake-slack take-up, the combination with a push-bar, of a lever-block movably mounted on the push-bar and provided with means for engaging the push-bar, a resilient device interposed between the pushbar and lever-block and having means for engaging the lever-block, and a distance-stop arranged in the path of said resilient device; substantially as and for the purposes specified.

et. In a brake-slack take-up, the combination with a push-bar provided with a rack, of a sliding lever-block arranged thereon and provided with a dog to engage the rack of the push-bar, a spring-bar provided with a rack, a dog on the lever-block adapted to engage the'rack of the spring-bar, and a distancestop; substantially as and for the purposes specified.

5. In a brake-slack take-up, the combination with a push-bar, a lever-block mounted thereon and provided with means for engaging the push-bar, of a spring-bar having reverse-racks upon its opposite faces, a fixed dog and a movable dog on the lever-block said dogs arranged to engage the racks of the spring-bar, and an inclined distance-stop adapted to lift the spring-bar from engagement with the fixed dog; substantially as and for the purposes specified.

6. In a brake-slack take-up, the combination with a push-bar, a movable lever-block arranged on the push-bar and provided with means to engage the same, of a spring-bar interposed between the push-bar and leverblock and provided with means for engaging the lever-block, and a distance-stop provided with an incline to lift the spring-bar and an overhang to limit the rise of the spring-bar, substantially as and for the purposes specified.

7. In a brake-slack take-up, the combination with a push-bar, and a hand-brake rod, of a lever-block movably mounted on the push-bar, a lever connected with the leverblock, a resilient device interposed between the push-bar and lever-block, and means for causing the lever-block to engage the push- IOO IIO

bar and the interposed resilient device Whereby the relation of said parts are preserved when operated through said hand-brake rod; substantially as and for the purposes specified.

S. In a brake-slack take-up, the combination of a push-bar, a lever-block, a floating lever, a hand-brake pull-rod, and means for locking the lever-block on the push-bar when a pull is exerted on the hand-brake rod; substantially as and for the purposes specified.

9. In a brake-slack take-up, the combination with the push-bar of an air-brake, of an offset push-bar extension, and a lever-block movably mounted on said offset push-bar extension; substanfiallyas and for the purposes specified.

10. In a brake-Slack take-up for freight-car service, the combination with an air-brake piston and an independent push-bar, of a fioating lever, a hand-brake pull-rod connectin(r with said fioating lever, and means for locKin g the floating lever to the push-bar, substantially as and for the purposes specified.

1l. In a brake-slack take-up for freight-car service, the combination with an air-brake piston and an independent push-bar, of a floating lever, a hand-brake pull-rod connecting with said floating lever, a device for locking the floating lever to the push-bar, and means for releasing the locking device after a predetermined travel of said push-bar; substantially as and for the purposes specified.

In testimony whereof I affix my signature, in presence of two Witnesses, this 25th day of April, 1898.

JOHN C. XVANDS. Witnesses:

HUGH K. WAGNER, F. R. CORNWALL.

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