US1980084A - Power-operated lock for spring switches - Google Patents

Description

Nov. 6, 1934. J. A. PEABODY POWER OPERATED LOCK FOR SPRING SWITCHES Filed July 2, 1930 INVENTO ATTORNEY Patented Nov. 6, 1934 UNlTED STATES PATENT OFFICE POWER-OPERATED LOOK FOR SPRING SWITCHES Application July 2, 1930, Serial No. 465,306

19 Claims.

This invention relates to power-operated locking devices for spring switches.

Track switches, commonly known as spring switches, are held in one position, usually the normal position, by a heavy spring, which acts to return the switch points automatically to the normal position when the switch is trailed, a suitable oil dash-pot device being commonly employed to retard the return movement of the switch points, so that the points are not shifted back and forth by the successive wheels of the train trailing the switch. Since the spring or some of the connections to the switch points may be broken or otherwise out of order, so that the points might be displaced by the wheels of a train passing over the switch in the facing direction, and thereby cause derailment, it is not considered safe for a train to travel over a spring switch in the facing direction at normal speeds. There are many applications of spring switches, however, where train delays would be avoided if trains could pass over the spring switch in the facing direction at the normal running speeds and not be required to reduce speed.

In accordance with this invention, it is proposed to provide locking means of the plunger type for positively holding the switch points in the normal position, so that when this locking means is effective, trains may safely pass over the switch in the facing direction at high speeds.

One object of the present invention is to provide a power-operated locking means for holding a spring switch in the normal position, this locking means being normally ineffective, and also to provide suitable controlling means for the locking means, so that the switch is automatically locked upon approach of trains travelling in the facing direction, but remains unlocked for a train travelling in the opposite direction and trailing the switch.

A further object of the invention is to control the signals, governing traffic in opposite directions over a spring switch, in accordance with the locked or unlocked condition of the switch, so that the signal governing trafiic in the'facing direction over the switch cannot clear unless the switch is locked, and the signal governing traflic in the opposite or trailing direction cannot clear if the switch is locked.

Other objects, characteristic features and advantages of the invention will be in part apparent, and in part pointed out, as the description progresses.

The accompanying drawing illustrates in a simplified and diagrammatic manner one typical embodiment of the invention applied to a spring switch at one end of a passing siding on a single track railroad, assumed to be equipped with an automatic block signal system, the parts and circuits being shown in this drawing more with the object of making it easy to understand the nature and principles of the invention, than for the purpose of showing specifically the mechanical construction and arrangement of parts and circuits that would be preferably employed in practice.

Referring to the accompanying drawing, the track switch SW, shown conventionally, is of the usual type and construction. Mechanically connected to the movable points of this switch SW in the usual way is a suitable spring and dashpot mechanism, shown conventionally and designated S, which acts in the usual way to move the switch points to the normal position and hold them in that position. A switch stand or handthroW mechanism HT of the usual construction is also connected to the switch points, so that the switch may be shifted manually to the reverse position, to permit trains to enter the siding. This hand-throw device HT is preferably connected to the spring mechanism S so that the switch points may be thrown without acting in opposition to the spring.

The track is divided into track circuit sections 5, 6, '7 and 8 in the usual way, each track section having a track battery and a track relay, these track relays being designated 5T, 6T, etc. The track circuit section 'lis relatively short as shown, for example, about 800 feet long; and the track circuit section 8 is the usual detector track circuit section at the switch SW. An absolute or stopand-stay signal 2 governs train movement from right to left into the stretch of single track between the end of the siding shown and the next adjacent siding. The approach permissive signal 1 governs traffic in the facing direction' over the switch SW; and the signal 3, next in the rear of the signal 1, governs traffic in the same direction as'signal 1.

These signals 1, 2 and 3, which are illustrated conventionally as semaphore signals, but may be color-light signals or any other suitable type, are assumed to be controlled in accordance with the circuits and principles of the well-known type of block signalling system for single track railroads, commonly known as the absolute-permissive-block system. A block signal system of this type is shown and described, for example, in the patent to S. N. Wight, No. 1,294,736, dated February 18, 1919. In order to simplify the i1- lustration, no attempt has been made to show all of the circuits for the control of the signals 1, 2 and 3, only those circuits more directly related to the invention having been conventionally illustrated; but reference may be made to the patent to S. N. Wight, above mentioned, for other detailsof the signalling circuits.

Each of these signals 1, 2 and 3 is controlled by a suitable signal or line relay, usually of the neutral-polar type to provide for three positions or indications. The line relays 1H and 2H are shown for controlling the signals 1 and 2, but

the caution control for these signals is omitted.

The energizing circuits for these relays are more conveniently discussed later in connection with the explanation of the operation of the invention.

The locking device or mechanism of this invention, illustrated conventionally and included within the dotted lines WL, comprises a lock rod LR, connected in the usual way to the movable points of the switch SW. A locking bolt or plunger 10 is arranged to enter a hole 11 in this lock rod LR, when the switch SW is in the normal position, and thus positively lock the switch points. Said lock rod LR and locking plunger 10 are suitably supported and guided in a frame or casing partially indicated at 12. The locking plunger 10 is connected by'a pivoted link 13 to a gear14. Fastened to the shaft 15 (indicated in part by a dash line) to which the gear 14 is fixed, are two circuit controlling earns 16 and 17. Projecting insulated lugs on these cams 16 and 17 co-operate with rollers on spring contact fingers 18, 19, 20 and 21, so as to move these fingers into and out of engagement with stationary contacts, indicated conventionally as arrows.

The main gear 14 of the locking mechanism WL is driven by a suitable electric motor M, having an armature 22 and two reversely arranged field coils or windings 23 and 24, through a friction' clutch 25, and suitable reduction gearing, illustrated as one pinion 26. The shaft of the motor M is provided with a socket 27 to receive the end of a hand crank 28, so that the motor shaft may be turned by hand. Suitable provision is made for cutting off the'supply of current to the motor M when the hand-crank 28 is used. As shown, the hand crank 28 when not in use is assumed to compl'ete a circuit through contacts 29 included in the motor circuit, so that when the hand crank is removed and inserted in the socket 27, the circuit through the motor armature is broken. Any other suitable means,

'7 such as'disclosed, for example, in the patent to W. K. Howe, No. 1,466,903, dated Sept. 4, 1923, may be employed for the same purpose.

Considering now the mode of operation of the invention, the parts and circuits are shown in the usual or normal condition, the locking plunger 10 being disengaged from the lock rod LR, and the switch being unlocked. indicates stop, and the signal 3 next in the rear indicates caution. The signal 2indicates clear.

Assuming that a train, travelling from left to right in the facing direction toward the switch SW, enters the stretch of single track at the left of this switch, then the energizing circuit for the line relay 2H is broken, to cause the signal 2 to indicate stop, by the action of the tumble-down circuits characteristicof the absolute-permissive-block system, as disclosed more in detail in said patent to S. N. Wight above mentioned. The de-energization of the 'line re- 5 lay 2H closes an energizing circuit for the motor The signal 1v M of the locking mechanism so as to lock the switch SW. This circuit may be traced from indicating a connection to one terminal of the battery or other suitable source of current, through the front contact 30 of the track relay 7T, wire 31, front contact 32 of track relay 8T, wire 33, back contact 34 of relay 2H, wire 35, back contact 36 of a directional stick relay 2S, wire 37', contact finger 19, wire 38, motor field winding 23, wire 39, armature 22, wire 40, through crank controlled contacts 29, to indicating a connection to the other terminal of this battery.

When the armature 22 and the field winding 23 of the motor M are thus energized, the gear 14 is turned from the position shown in a clockwisev direction, to move the locking plunger 10 into the hole 11 in the lock rod LR, and thus positively lock the switch SW in its normal position. In this locked position of the locking plunger 10, the end of the connecting link 13 is beyond dead center and adjacent to the fixed stop 41, so that the locking plunger 10 cannot be displaced by vibration or the like from its locking position. I

During this movement of the gear 14, the circuit controller cams 16 and 17 are shifted from the positions shown approximately a half revolution, to open the contact fingers 19 and 20, and close the contact fingers 18 and 21. The opening of the contact finger 19 breaks the motor energizing circuit above traced, so that operating current is cut off from the motor at the end of this locking operation.

The closing of the contact finger 21, at the end of this locking operation, completes a break in the energizing circuit for the line relay 1H, so that if traiiic conditions permit, this relay 1H may be energized over a circuit, which is only partially shown and may be traced from (C), indicating a connection to the usual common return wire, relay 1H, wire 42, front contact 43, track relay 7T, wire 44, front contact of track relay 8T, wire 46, which preferablyincludes a switch circuit controller contact WP, closed inthe normal position of the switch, contact finger 21, wire 47, and thence through other controlling contacts of the signalling system, to a source of current connected to the common return wire.

Thus, when a train approaches the switch SW in the facing direction, the locking mechanism WL is operated to lock the switch, and if this locking operation actually occurs, then only may the signal 1 clear.

If the switch SW should not be over in the full normal position, or if the locking plunger 10 cannot enter the hole'll in. the lock rod LR for any other reason, the gear 14 can not be moved far enough to close the contact finger 21, and the signal 1 can not clear. In such a case, the friction clutch 25 slips; and if desired, suitable timeelement means such as disclosed, for example, in the application of S. N. Wight, Ser. No. 293,664, filed July 18, 1928, may be employed to cut off theoperating current, after the lapse of a predetermined time, in case of failure in the locking operation.

jVhen this train in question, assumed to have caused locking of the switch, has passed beyond the switch SW and out of the detector track cirof track relay 8T, wire 33, front contact '34'of relay 2H, wire 48, contact finger 18 (now closed) wire 49, motor field 24, and thence through the armature 22 to the same as in the locking circuit.

With the motor field 24 energized, the armature 22 of the motor M rotates in the opposite direction and drives the crank 14 counter-clockwise to withdraw the locking plunger 10 to its unlocked position. This opens the circuit for the line relay 1H, putting the signal 1 tostop; opens the contact finger 18 to cut off the operating current to the motor M; and closes the contact finger 20 to complete a circuit for clearing the signal 2, which may be traced from through the front contact 50 of the relay 2H, signal 2, wire 51, and contact finger 20 to In this way, the switch SW is automatically unlocked, after passage of the train in the facing direction which caused locking of the switch.

When a train on the siding trails the switch SW, the switch points may be freely moved, since the lock plunger 10 is then disengaged. If the switch SW should be locked for any reason, the signal 2 is held in the stop position, irrespective of the control of its line relay 2H, by the opening of the contact finger 20.

When a train trailing the switch SW enters the track circuit section '7 and de-energizes the line relay 21-1, the locking circuit for the motor M is broken at the front contact 30 of the track relay 7T before it is closed at the back contact 34 of the line relay 2H. Also, the directional stick relay 2S is energized over a circuit from through the back contact 30 of the track relay 7T, wire 52, circuit controller 53 of signal 2, closed in the clear and caution positions, wires 54 and 55, relay 2S to and when the line relay 2H drops, the stick relay 2S is stuck up through its front contact 56 and a back contact 5''! of the relay 2H. The energization of this stick relay 2S breaks at its back contact 36 the locking circuit for the motor M, so that after the train in question, travelling in the trailing direction, passes out of the track circuit section '7 and into and through the track circuit sections 5 and 6, this locking circuit is maintained open and an idle locking operation is avoided.

The directional stick relay 23 is also picked up by a train travelling from right to left past the switch SW on the main track; and consequently the locking mechanism WL is not operated to lock the switch when this train advances into the approach locking track circuit sections 5 and 6, as otherwise would occur if'it were not for this stick relay 2S and its control of the locking circuit. For such a train movement in the trail ing direction over the switch SW in its normal or main track position, it is not necessary to lock the switch points, since the wheels of the train will keep the switch points in the proper normal position, even though the spring and dash-pot mechanism S may not be fully effective.

From this explanation it can be seen that, for a trailing train movement, the signal 2 cannot clear if the locking mechanism WL is effective to lock the switch SW. In other words, the points of the switch SW must be free to be moved, if necessary, by the wheels of the train trailing the switch, before the signal 2, governing traffic in the direction of such trailing movement, can clear. This prevents damage or breaking of the locking device or other parts associated with the switch, which would otherwise occur, if the wheels of the train would force over the switch points from the locked position.

If the locking mechanism WL, clue to a failure in the operating parts or circuits, or for any other reason, should not lock or unlock the switch when'it should, the hand crank 28 may be used to operate the main gear 14 by hand, and move the locking plunger 10 into or out of engagement with the lock rod LR. For example, if the looking mechanism WL should fail to unlock having once been locked by an approaching train, the switch may be unlocked by hand to permit a train to come off" of the siding and trail through the switch. Also, when a train approaching the switch SW in the facing direction automatically locks the switch, as above explained, it is necessary to use the hand crank to unlock the switch before the switch stand or handthrow device HT can be operated to reverse the switch and permit this train to enter the siding. When the hand-crank 28 is in use, the circuit through the motor armature 22 is broken at the contacts 29.

This invention provides for the desirable and requisite safety in the use of a spring switch and permits train movements at normal speeds in the facing direction over the switch, thereby facilitating trafiic. The signals 1 and 2, governing traffic in opposite directions over the spring switch, are controlled in such a way that these signals may not clear unless it is safe for the train to pass over the switch, that is, is positively locked for train movements in the facing direction and unlocked for train movements in the trailing direction. The switch points of the spring switch are positively and securely held by a lock of the plunger type; and since this locking plunger is power-operated, the parts may have the necessary size and strength, and yet the switch may be automatically locked and unlocked, as required, in spite of the friction and pressures ordinarily encountered in practice in connection with a plunger type lock. Also, provision is made for operating the switch look by hand, when necessary, either because the looking mechanism is out of order, or because a train wishes to enter the siding. Various other characteristic features and advantages of the invention will be apparent.

The present invention is an improvement upon the disclosure in the prior application of Preston and Dicke Ser. No. 187,490 filed April 29, 1927, and no claim is made in this application to any of the subject matter disclosed in said prior application.

The particular construction and arrangement of parts and circuits shown and described are merely illustrative of one specific embodiment of the invention, considered diagrammatically, rather than structurally; and various additions, modifications and adaptations may be made in this specific embodiment without departing from the invention.

What I claim is:-

1. 'In a traffic controlling system for railroads, a track switch, spring means tending to move and hold said switch in the normal position, a lock rod and locking plunger engageable only in one 146 position of the switch for locking said switch, and power-operated means for moving said lock plunger to its locked and unlocked positions.

2. In a traffic controlling system for railroads,

a track switch, spring means tending to move and 145 hold said switch in the normal position, locking means for positively holding said switch in its normal position, power-operated means governed by the approach of a train for actuating said locking means, and manually operable means for 150 Sill GOT

independently actuating; said locking means.

3. In a traffic. controlling system for'railroads, a track switch, spring means tending to move and hold said switch in the normal position, a plurality of track circuit sections adjacent the switch, a normally energized line relay governed by said track circuits and deenergized upon occupancy of any of said track circuits by a train, normally in-' active locking means for said switch, and poweroperated means governed by said line relay for rendering said locking means effective upon the approach of a train travelling in the facing direction toward said switch.

4. In a trafiic controlling system for railroads, the combination with a spring switch, a locking plunger for positively holding said switch in its normal position only, an electric motor and gearing for operating said plunger, and manually operable means for also operating said plunger.

5. In a trailic controlling system of the type described, a spring switch, signals governing traffic in opposite directions over said switch, a lock rod connected to the points of said switch, a locking plunger co-operating with said lock rod to hold said switch points in the normal position,

power-operated means for positively moving said plunger to and from its locked position, and circuit controlling means op'eratively connected. to said plunger for selectively controlling said signals.

6. In a traflic controlling system for railroads, a spring switch, a plurality of track circuits adjacent the switch, a line relay governed by said track circuits, a stick relay responsive to the direction of train movement over said track circuits, power-operated locking means for said switch, and a control circuit for said means including a back contact of said stick relay and a back contact of said line relay. 7

7. In a system of safety control for spring switches, a plurality of track circuits adjacent the spring switch, a line relay governed by said track circuits, a signal governing traffic in the trailing direction over said switch, power-operated'locking means for the switch governed by said line relay, and a clearing circuit for said signal controlled by said line relay and by said locking means.

8. In a railway signalling system of the type described, the combination with a spring switch, a track circuit adjacent the switch and having a track relay, a normally disengaged plunger lock for said switch, power-operated means for actuating said lock to its locking position, and a control circuit for supplying power to said means including a front contact of said track relay.

9. ,A locking mechanism of spring switches comprising the locking plunger, power-operated means having locking and unlocking control circuits for actuating said plunger, a plurality of track circuits adjacent the switch, and a line relay controlled by said circuits for alternatively governing said controlcircuits.

10. Looking means for spring switches, comprising a locking plunger operable both manually and by power, and signal control circuits selectively governed in accordance with thelocked or unlocked position of said plunger.

11. In a traffic controlling system for railroads, a track switch, spring means tending to move and to hold said switch in the normal position, a signal governing traffic toward said switch in the facing direction, normally inactive locking means for positively holding said switch in its normal position, power-operated means electric motor and gearing for rendering said locking means effective upon the approach of a train in the facing direction, and means for preventing the clearing of said signal unless said locking means is in its locked condition.

12. In a traffic controlling system for railways, a track switch, a signal governing trafl'ic toward the switch in the facing direction, locking means for positively holding the switch in one extreme position, and reversible motor operated means for rendering the locking means effective upon the approach of a train in the facing direction so as to put said signal to stop.

13. In a traflic controlling system for railways, a track switch, locking means for positively holding the switch in one extreme position, and reversible electrically controlled motor operated means for rendering the locking means efiective only upon the approach of a train in the facing direction.

14. In a railway signal system, in combination, a stretch of track, a track switch, lock meansfor the switch, power operating means for the switch lock means, a signal governing traflic over the switch in one direction, and a translating device controlled by trafiic approaching the switch from the other direction, for simultaneously operating said signal and for making the power operating means effective to control the lock means.

15. In a railway signal system, in combination, a stretch of track, a track switch, lock means for the switch, power operating means for the switch lock means, a signal governing trafiic over the switch, in a switch trailing direction, and a relay controlled by traffic approaching the switch from the facing point direction, for simultaneously operating said signal to stop and for making the power operating means effective to control the lock means to lock the track switch.

16. In .combination, a trailing fiy-back switch, a lock means for the switch comprising, a looking plunger and lock rod engageable only in the normal position of said switch, and an electric motor and gearing for operating said plunger to its locked and unlocked positions.

17. A locking device for trailing fly-back switches comprising, a lock rod connected to the switch points, a locking plunger, the lock rod'being engageable only with said locking plunger and then engageable with said lock rod only in the normal position of the switch points, an electric motor and gearing for operating said plunger to the locked and unlocked positions, and circuit controlling means automatically opened and closed in accordance with the position of said plunger.

18. A locking device for trailing fiy-back switches comprising, a lock rod connected to the switch points, only a single locking plunger engageable with said lock rod and then only in one position of the switch points, an electric motor, and gearing including a friction clutch for operatively connecting said plunger to said motor.

19. In a traffic controlling system for railways, a trailing fiy-back track switch, locking means for positively holding'the switch in one extreme position, and reversible motor operated means for rendering the locking means efiective upon the approach of a train in the facing direction only.

JAMES A. PEABODY.

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