US2858419A - Emergency key release latch for electric locks - Google Patents

Description

Oct. 28, 1958 H. L. BONE ET AL 2,85

EMERGENCY KEY RELEASE LATCH FOR ELECTRIC LOCKS Filed May 12, 1954 5 Sheets-Sheet l INVENTORS Herbert L. 60129 and John W Logan J1:

7 1mm ATI'oRylzr Oct. 28, 1958 H. BONE ETAL EMERGENCY KEY RELEASE LATCH FOR ELECTRIC LOCKS Filed May 12, 1954 3 Sheet sSheet 2 l/ll/l/l/l/ lnsalqtimz 5,9

Fey 2 I INVENTORS Herbert L.Bone and BY Jblzzz Wboyan J1:

MAW

THEIR ATTflHNEY Oct. 28, 1958 H. BONE ET AL EMERGENCY KEY RELEASE LATCH FOR ELECTRIC LOCKS 3 Sheets-Sheet 5 Filed May 12, 1954 fi a m 8. Q N %N WA MN O gm; mm Tm R m R m i Q N\\ mm Wm Ne 3 wum aazc QE ww R mw m NWQN QR NM mm R R mm .3 N% m v m ww Q m w NA. in 14%... \A n I w Nam NW HHHHHHJWWM QW mwm u m N w m w R R n Q6. v. v NM, Emfi N WW 5 fimww .w w QM l Q3 mm, 6 Q a m m 1 J 4 m! R g f w n Q I Mo ,WF v I J! J n 7 mm vw i. mm Sv m A m .K w n m. R L 0 1 QS N mm M Wm J F r" L \w a Q kw I l--:..... MC C H L QN EMERGENCY KEY RELEASE LATCH FOR ELECTRIC LOCKS Herbert L. Bone and John W. Logan, Jr., Forest Hills, Pa., assignors to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application May 12, 1954, Serial No. 429,247

10 Claims. (Cl. 246-159) Our invention relates to lock devices for railway track switches, derails, and the like, and particularly to emergency key release latches for electric locks.

In railway signaling and trafiic controlling systems, outlying track switches are commonly protected against operation by unauthorized persons by means of padlocks which may be opened by keys carried by certain selected railway personnel. It is sometimes necessary or desirable to supplement the protection obtained from the use of a padlock by adding another lock which may be controlled from a remote point or automatically in accordance with traflic conditions. A common expedient is to provide an outlying track switch associated with a main track or the center stand of a crossover connected to the operating mechanisms of the two track switches, with an electric lock, such as illustrated for example in Letters Patent of the United States No. 2,517,280, granted August 1, 1950, to Herbert L. Bone et al. The supplemental control imposed by an electric lock of this type permits selected railway personnel provided with the necessary keys to initiate the unlocking of the hand-throw lever, energization of the lock magnet of the electric lock being required before the lever latch may be moved out of the way to free the hand-throw lever.

An emergency key release is often incorporated in such electric locks to enable a trainman to unlock the electric lock without Waiting for the electric unlock if conditions are such that he is authorized to do so. To opcrate the emergency key release of such an electric lock, a trainman must first break a seal before he can insert his key in the release mechanism. There have been times, however, when trainmen have broken the seal and used the emergency key release Without authorization. In such cases, the fact that the emergency key release has been used without authorization might not be brought to the attention of the proper authorities until a signal maintainer on a periodic inspection tour finds the broken seal on the electric lock. Considerable time may have elapsed between the unauthorized use of the emergency release and the discovery of the broken seal on the electric lock. With the seal broken, the person responsible for the unauthorized use cannot be ascertained nor can there be any check made as to how many times the electric lock was released without authority.

It i therefore an object of our invention to provide a latch for the emergency key release of electric locks which operates whenever the key release is used and prevents the control contacts of the lock from returning to their normal or locked position.

It is a further object of our invention to provide an emergency key release latch for electric locks which may bereset only by a maintainer equipped with the proper key for the electric lock housing.

Another object of our invention is to provide an emergency key release latch for electric locks which will permit the electric lock to be padlocked even though the control nited States PatentO 2,858,419 Patented Oct. 28, 1958 contacts of the electric lock are in their unlocked position.

Still another object of our invention is to provide a safeguard for the emergency key release latch to maintain and insure the proper alignment of the latch mechanism with the key release mechanism.

In carrying out the foregoing and other objects of our invention, we provide a spring biased latching member for an electric lock similar to that shown in the aforesaid patent. With reference to the aforementioned patent, the foot pedal is provided with a spring biased stop sleeve which, upon depression of the foot lever to release the hand-throw lever, is moved in the direction of the foot lever. As more fully shown and described in the aforesaid patent, the stop sleeve cooperates with a locking dog which is under the control of an electromagnet. Energization of the electromagent will lift the locking dog out of the path of the locking sleeve to permit the depression of the foot pedal of the electric lock. Movable with the foot pedal is a camming nut which cooperates with a contact operating cam so that the depression of the foot pedal in releasing the hand-throw lever will move the cam to a position in which the electric contacts of the lock are actuated.

The latching member of our invention is so arranged within the electric lock that a trigger arm secured to the key barrel of the emergency key release will release the latching member. The end of the latching member will abut the locking sleeve but, as the foot pedal is depressed to release the hand-throw lever, the end of the latching member will be inserted behind the locking sleeve, thereby preventing its return. The foot pedal, however, will be permitted to return to its normal position so that the hand-throw lever may be locked in its normal or locked position. The holding of the locking sleeve in its forward position, however, prevents the locking dog from returning to its inoperative position. The retained operative position of the locking dog retains the armature of the electromagnet in its operative condition to maintain the signal contacts in their actuated or unlocked positions. To release the latching member it is necessary for a maintainer provided with the necessary key to open the case of the electric lock and reset the latching member. The resetting of the latching member will permit the locking sleeve to return to its unlocked position, thereby permitting the locking dog to assume its locked position. The return of the locking dog to its locked position will permit the armature to return to its locked position, the actuated contacts returning to their normal or locked position. Thus a trainman after using the emergency release mechanism may leave the electric lock prior to the arrival of a maintainer with the certainty that no one without a key to the padlock of the lever latch can operate the foot pedal of the electric lock to free the hand-throw lever.

Other objects and characteristic features of our invention will become apparent as the description proceeds.

In the accompanying figures of the drawings wherein similar reference characters designate similar parts in each of the several views,

Fig. 1 is a top elevational view showing the association of a lock device as shown in Letters Patent of the United States No. 2,517,280 to a center stand disposed between the rails of a crossover.

Fig. 2 is a top view of the electric lock with the cover removed, portions of the electric lock being broken away to show the details of our latch mechanism.

Fig. 3 is a fragmentary end view of the key barrel andthe trigger arm for releasing the latching member upon operation of the emergency key. release, as viewed along line III-J11 of Fig. 2.

Fig. 4 is a sectional view taken approximately along the line IVIV of Fig. 2.

Fig. 5 is a sectional view taken approximately along the line V-V of Fig. 2.

Fig. 6 is a-view similar to Fig. 5 illustrating the positions of the locking sleeve 28 and the locking dog-'30 after a latchout, and of the locking rd-22 with the lever latch padlocked.

Fig. 7 is a sectional view taken along the line NIL-VII of Fig. 4.

Fig. 8 is a portion of Fig. 4 showing in enlarged scale the emergency key releasemechanism, while "Fig. 9 is 'a sectional view taken approximately along the line IX--IX of Fig. 8.

Referring now in detail of Fig. 1 of the drawings, the reference character l designates a center stand having a hand-throw lever 2 for operating a mechanical pipe connection 3 connected to manually operable switch operating mechanisms as illustrated in the aforesaid patent. Hand-throw lever 2 is operable between two' extreme positions in which the pipe connections 3 will actuate the switch operating mechanisms. An electric lock 4 associated with hand-throw lever 2 is effective to permit operation of the stand lonly when conditions are proper for such operation. The electric lock 4 is controlled to permit operation of the hand-throw lever 2 only when the electromagnet of the lock is energized by a control circuit which may be effected by an operator of a centralized traffic or remote control system, and/ or by automatic control imposed by-track circuits, positions of signals, etc., asis well understood in the art. As will hereinafter be more fully described, the electric lock 4 may be released by an emergency key release. The handthrow lever 2 of the center stand has a normal position in which it is illustrated and may be operated-through an angular movement of substantially 180 to a reverse position. The lever 2 is shown in its locked position inthe electric lock 4 which is secured to a supporting plate 5 on ties 6.

The electric lock 4 comprises a housing 7 enclosed at its upper end by a hinged cover 8. The housing is provided with a hasp 9 while the cover is provided with a staple 10, the bail of a padlock 11 passing through the staple to lock the housing against unauthorized access. The housing 7 is provided at its forward side with an integral extension 12 (Fig. 5) formed at its outer end with an upturned leg 13 and. with spaced vertical. standards 14 which, together withleg 13, form a jaw for receiving the hand-throw lever 2 of the center stand when the lever is in its locked or normal position. The

lower portions of standards 14 support a pivot pin 15 on which is pivotally mounted a lever latch 16 movable between a padlocked position, as. illustrated in Fig. 5, through an intermediate latching position, to an unlatchedposition. In both .the padlocked and intermediate positions of .the lever latch, the latch projects. into theupper end of the jawin such a manner as to prevent movementof the hand-throw lever 2 pasttthe latch. In the unlatched position, latch 16 is withdrawn from the jaw to permit movement of the hand-throwlever. In the padlocked position of latch 16, a hasp staple 17 provided on leg 13 projects through a suitable opening 16a of latch 16, the bail 17a of apadlock, not otherwise illustrated, locking the lever latchrin its padlocked position. Formed integrally with latch 16 are a treadle 18 and a bifurcated crank arm 19, the crank arm being provided at its outer ends with slotted openings 20 which engage a pin 21 carried on the outer end of a locking rod 22. The locking rod22 is mounted for lateral sliding movement inopenings 23a formed in a housing extension 23 in the forward side wall of the housing 7.

The inner end of rod 22 which projects into the housing is formed of reduced diameter to provide a shoulder 24 on the rod. The extreme inner end of the rod is threaded into a cam nut 25 slidablymounted in a slotted opening 26a provided in a boss 26 formed integrally with housing 7. Sleeved collars 27 and 28 and a coil spring 29 are slipped over the reduced portion of the rod 22 before attaching the nut 25, the spring 29 being disposed between the inner faces of the collars. Sleeved collar 28 will hereinafter be referred to as the locking sleeve 28. When the rod 22 is in its padlocked position, spring 29 is provided with suflicient initial compression so that collar 27 is urged constantly by spring 29 into engagement with shoulder 24 of the rod 22, while the locking sleeve 28 is forced by the spring 29 into engagement with the end 26b of the boss 26. In this condition of the parts the spring 29 is compressed, tending to bias the rod 22 toward the right as viewed in Fig. 5. When the bail 17a of the padlock is removed from the hasp staple 17, the parts'are so proportioned that the collar 27 and locking sleeve 28 will be driven apart by the spring 29 until the collar 27 engages the adjacent end wall 23b of the housing extension 23. The rod'22 will thus be moved to the right, as viewed in Fig. 5, to move cam nut 25 to the position where it just touches locking sleeve 28. In this position, which is referred to asthe intermediate or unlocked position, the collar 27 and locking sleeve 28 will engage the confronting surfaces of shoulder 24 and cam nut 25, respectively. The cam nut 25 is threaded on the rod 22 to a position so selected that, when collar 27 and locking sleeve 28 are in engagement with the respective confronting surfaces of shoulder 24 and nut 25, the collar 27 and locking sleeve 28 also engage the end 23b of the housing extension 23 and the inner end 26b of the boss 26, respectively. The housing extension 23 and the boss 26 constitute stops for the collar 27 and locking sleeve 28, respectively, in the intermediate or unlocked position of the rod 22.

A locking dog 30 is carried on the end of a bar 31, the other end of which bar is secured to one arm of a lever 32 (Fig. 4) pivotally supported on pivot pin 33. The pivot pin 33 is mounted in depending lugs 34 provided on a supporting strap 35 secured to a magnetic bracket 36. The magnetic bracket 36 is fastened by bolts 36a to the bottom wall of housing 7. The other arm of the lever 32 carries an armature 37 adapted to be attracted by an electromagnet 38 mounted in the bracket 36. In the condition of the parts shown in Fig. 4, the magnet 38 is deenergized and the dog 30 is disposed in the path of movement of the locking sleeve 28 between the inner end of the locking sleeve and the end 3911 of a plate 39 secured to the top of housing extension 23 to prevent movement of the locking sleeve to the right, as viewed in Fig. 5. The magnet 38 when energized will attract the armature 37 to lift the dog 30 out of the path of movement of locking sleeve 28 provided that a depressor 40 and a hold-down spring 40a, hereinafter more fully described, are lifted clear of the bar 31. Checking contacts, generally designated by the reference character 41, for checking the position of armature 37 of the electromagnet 38 and comprising fixed and movable contact fingers, not shown in detail, are mounted on a terminal block 42 secured to bracket 36. The checking contacts 41 are operated by the armature 37 through an insulating driving member 43 connected by a pin 43a to the bar 31 and suitably connected to the movable contact fingers, as set forth in the aforesaid patent.

Housing 7 is provided with an opening 44 in its end adjacent to the armature 37, and a housing member 45 is suitably secured to the housing 7 in alignment with the opening 44 (Figs. 4, 8 and 9). Housing member 45 contains a locking mechanism 46 which may take any -desired form. The arrangement is such that, when a proper key is inserted into the mechanism, it may be rotated to rotate an actuating member 47 driven by the lock mechanism and projecting into the housing 7. The actuating member 47 has a cammed surface 48 which cooperates with a cam follower 49 provided on a depending spring 50 supported from the supporting strap 35.

Upon turning of the key barrel, the cammed surface 48 drives the spring 50 toward the armature 37 so that an insulating pin 51 carried on the spring 50 is forced into engagement with the armature 37 and drives it to the pole pieces of the electromagnet 38. Bar 31 is thus rotated to lift the locking dog 30 out of the path of movement of the locking sleeve 28 permitting the treadle 18 to be depressed to move the locking rod 22 to the right, as will be described in detail hereinafter. The housing member 45 ofthe lock release is preferably enclosed by a hinged cover 52 biased by a spring 53 to cover the locking mechanism of the release, eyelets 54 or the like being provided on the housing and the cover through which a sealing wire or band (not shown) is passed to seal the lock release mechanism.

An insulating terminal block 55 (Figs. 4 and 7) fastened to the upturned leg of a contact supporting bracket 56 secured by bolts 56a to the bottom wall of housing 7 has molded therein two rows of contact terminals 57 and 58. A movable contact finger 59 is riveted to each terminal 57 and a fixed contact finger 60 is riveted to each terminal 58, the contact fingers 59 and 60 cooperating in pairs to provide mating contacts. Each movable contact 59 is operatively connected with an insulating driving member 61 in a suitable manner. The member 61 is guided at its upper end for up and down movement in a slotted guide 62 secured to the bracket 56, and carries near its lower end a laterally projecting pin 63. Block 55 and supporting bracket 56 have aligned openings 64 through which projects an arm 65 of a pivoted operating member 66 (Figs. 2 and 4), the arm being bifurcated at its end and provided with openings to receive the pin 63 of the driving member 61.

Operating member 66 comprises a substantially U- shaped member 67 (Fig. 2) provided with integrally formed trunnions 68, one of which is journaled in a bore 69'on the rear side wall of the housing 7, while the other is journaled in a trunnion screw 70 threaded through the front side wall of the housing and secured by a nut 71. Integrally formed with the U-shaped member 67 is the contact operating arm 65 described, and a dependent arm 72 (Fig. 4). Also formed on the U-shaped mem ber is a cam arm 73 having secured thereto on its under side a cam follower 74. Secured to an integral arm 75 of the U-shaped member is a depressor bracket 76. Secured to the depressor bracket 76, as by screws 76a, are the depressor spring 40a and a laterally projecting member 77, the screws 76a passing through the bracket 76 and threaded into suitable openings provided in the depressor 40 disposed in axial alignment with the arm 75.

The dependent arm 72 on the operating member 66 cooperates with a coil spring 79 confined between the arm and a boss 80 formed in the housing 7. The coil spring 79 biases the operating member 66 in a clockwise direction, as viewed in Fig. 4, about its point of pivotal support 68. In the biased clockwise position of the operating member 66, the cam follower 74 on cam arm 73 is disposed in engagement with the cam nut 25 on the locking rod 22, with the cam follower 74 disposed just clear of a mating beveled surface of the nut 25 (Fig. 5). The depressor spring 40a is forced firmly into engagement with the top of the bar 31 carrying the dog 30. The depressor 40 is disposed above and just clear of the bar 31, and the parts are so proportioned that the depressor spring 40a holds down the bar with sufficient force to overcome any tendency of the bar to raise the locking dog 30 out of the path of the locking sleeve 28 as, for example, due to the energization of magnet 38,'or in response to vibrational disturbances of the mech anism such as would be occasioned by passing trains, etc. The;driving member 61 is positioned by the arm 65 of the operating member 66 so that the contacts carried by block 55 assume the positions in which they are shown in Fig. 7. I

The electric lock is further provided with an indicator designated generally by the reference character 81 (Fig.

5). The indicator may be viewed through a window 82 provided in the cover 8 of the housing. As more particularly set forth in the aforesaid patent, the indicator 81 is actuated by the extending member 77 secured to the depressor bracket 76 of the lock.

The electric lock and center stand hereinbefore described operate in a manner similar to that described in Letters Patent of the United States No. 2,517,280. As more fully described in the aforesaid patent, the removal of the padlock bail 17a from the hasp staple 17 will permit the coil spring 29 to move the locking sleeve 28 to the right to its afore-described intermediate position, the cam nut 25 lifting the cam follower 74 and cam arm 73. Operating member 66 is thus rotated in a counterclockwise direction to lift the depressor 40 and depressor spring 40a to permit arm 31 to be raised upon energization of the electromagnet 38. Upon energization of the electromagnet 38 of the lock, the treadle 18 may then be depressed to move the locking rod 22 to its unlocked position, the locking dog 30 having been lifted so that the locking sleeve 28 may be moved to the right. In moving to its intermediate position, the locking rod will carry the cam nut 25 with it so that the camming surface on the cam nut engages the cammiug surface of the cam follower to lift the cam arm 73 of the operating member 66. The operating member 66 will thus be rotated in a counterclockwise direction (Fig. 4) to move the driving member 61 secured to the arm 65 in a downward direction, thereby actuating the contacts 59--6tl. The energization of the electromagnet 38 in rotating the arm 32 to lift the locking dog 30 moves the driving member 43 in an upward direction to actuate the checking contacts 41 secured to the terminal block 42. The actuation of the contacts 59-60 by the driving member 61 sets up the necessary circuits for thesafe operation of the center stand. The depression of the foot pedal 18 will remove the lever latch 16 so that the hand-throw lever 2 may be thrown to its reverse position. A return of the hand-throw lever to its normal position and the return of the lever latch 16 to its latching position will restore the electric lock elements to their intermediate positions. The lifting of the foot pedal 18 and the insertion of padlock bail 17a in the hasp staple 17 will restore the lock to its locked position as shown in Fig. 5.

As more fully described in the aforesaid patent, the use of the emergency release lock mechanism 46 will rotate the actuating member 47 so that the cammed surface 48 will move the cam follower 49 to the left, as viewed in Fig. 8, to move the spring 50 and its attendant pin 51 against the armature of the electromagnet 38. The clockwise rotation of the armature 37 about the pin 33 will move the arm 31 upwardly to lift the locking dog 30 to permit the movement of the locking sleeve 28 in the manner herein described.

In order to operate the emergency release lock mechanism, it is necessary for the trainman to cut the lock wire or band used in sealing the lock mechanism cover 52. Although the use of the emergency release lock mechanism in the initial case may have been authorized, the. sealing wire or band passing through the eyelets 54 of the cover and case of the emergency release lock mechanism will remain severed and any future use of the emergency release lock will not be detected. While an authorized use of the electric lock as described is brought to the attention of the maintenance department and a maintainer sent 'to reseal the electric lock, any unauthorized use of the electric lock may not be brought to the attention of the proper authorities for some time, or until a signal maintainer on a periodic inspection tour notices the broken seal on the lock. Since only the maintainer has access to the inside of the lock housing, a latching mechanism is now provided for the electric lock for preventing the resetting or clearing of the signals 7: set .by the actuated contacts of the electric lock,. the latching-mechanismpartsbeing; inaccessible from. the exterior of the housing.

To this end, therefore, thereeissecured to the interior of the housing 7 (Figs 2 and 3), a latch guide bracket 83 formed with two parallelarms. 83a ands3b, the arm 83b. being the longer of the two. At the junction of the short arm 83a with the bracket 83 an elongated opening 830 is provided; The longer arm 83b of the latch guide bracket is also provided with an elongated opening 83d. adjacent'to the end of the arm. Secured to the extreme end of the longer arm 83b of the latch guide. bracket .is a spring stud 84. Slidably received in theopenings 83c and.83d provided in the latch guide bracket. arms is, a latch bar 85, the latch bar being of an open 8. form. The end of the latch bar 85 cooperating with the shorter arm 83a of the guide bracket is providedwith. an elongated. notch 85a, while the other end of .the latch bar cooperating with the longer arm 83b of the guide bracket is formed with a reduced end 85b which passes through the opening 83d of the bracket. Secured to the latch bar'adjacent to the notch 85a is a spring; stud 86. Interconnecting the spring studs 84 and 86 is a coil spring 87, which tends to move the latchbar to the left, as viewed in Fig. 2. It will be noted that the right-hand edge of the notch 85a abuts the arm 831 1.of the latch guide bracket so that the latch 'bar is prevented from being moved toward the left by the coil spring 87.

To release the latch bar from the guide bracket, a trigger arm 88 is secured to the actuating member 47 of the locking mechanism 46 (Fig. 3). In rotating the actuating'member by the emergency key, the trigger arm 88 will be moved clockwise to abut the end of the latch bar 85 to release the latch bar notch from the guide bracket arm 83a. The coil spring 87 may now move the latch bar toward the left, the end 85b of the latch bar abutting the locking sleeve 28. It will be noted that the latch bar is tripped before the emergency key has rotated far enough to operate the lock armature. The latch bar will thus be tripped before the lever latch 16 is freed. After the latch bar has been tripped and the locking dog 30 lifted in the manner hereinbefore described, the depression of the foot pedal 18 will move the locking sleeve 28. toward the right as seen in Fig. 5. The movement of the locking sleeve will permit the spring 87 to move the latch bar end portion 85b behind the locking sleeve 28.so that the latch bar is now between thelocking sleeve and the end 2612 ofthe boss 26 as illustratedin Fig. 6. The lever latch will be operated in its normal manner to release the hand-throw lever 2.

The tripping of the latch bar upon use of the emergency key release will not prevent the padlocking of the electric lock: in the normal manner. However, since the latch bar is behind the locking sleeve 28, the locking sleeve will be prevented from returning to its normal position. The locking dog 30 will therefore be prevented from returning to its normal locked position (Fig. 6) so that the arm 31 is now kept in its extreme or energized position. The armature operated checking contacts 41 will thus be actuatedby the lifted arm 31 and lifted driving member 34 pivoted to the arm. The arm 31 being held up will hold up the arms 73 (Fig. 6) and 75 of the operating member 66 due to the abutment of the arm 31 with the depressor 40. The operating member 66 will thus be held in its counterclockwise or actuated position to maintain the contacts 59-60 actuated. Since the cover 8 of the housing 7 is locked by the padlock 11 to which only the maintainer has a key, it will be apparent that, Whether the use of the emergency lock be authorized or unauthorized, .the signals or circuits controlled over the contacts 59-60 provide a tell-talethat the emergency key release mechanism has been used.

To reset the signals or circuits actuated by the contacts 59 -60, the maintainer must'unlock the padlock 11 and remove the cover 8. By pushing the latch bar .to the right (Fig. 2), the tension of the coil spring 87 will cause the notch 85a of the latch bar to catch on the arm'83a of the latch guide bracket. It will be necessary before, the latch bar is released to step on the foot pedal 18 to release the pinching action of the lockingsleeve 28-to permit the withdrawal of the latch bar from behind the sleeve.

It will be noted that the right-hand end of the. latch. bar 85 is notched as at 850 to provide enough clearance to return the trigger arm to its normal positionaftertripping of the latch bar even though the left-hand end of the latch bar is still held against the locking. sleeve '28. As previously described, this condition exists until the trainman steps on the foot treadle. This feature .enables the. trainman to remove his key even though he may, for some reason, decide not to press the foot treadle'afterhehas used the emergency release. bar will be released the next time the foot treadle is-operated whether the locking dog is withdrawn by electrically 1 energizing the electromagnet or turning the key release.

In checking the electric lock4 hereinbefore described. during a regular tour of inspection, the maintainer may;

in the course of his work, accidentally trip the latchwbar- 85. The latch bar may easily be reset in the manner here-- in described. However, should the latch bar be tripped by the inadvertent rotation of the trigger arm 88- ina clockwise direction (Fig. 3) and the latch bar reset with the trigger arm beyond the latch bar as indicated in thedashed position of the arm in Fig. 3, it may prove diffi cult or impossible to insert a key in the emergency release mechanism due to the rotation of the locking mechanism 47 by the trigger arm.

To avoid this difficulty there is riveted to the-inside of the cover a protruding member 90 which, when the: cover is closed, extends into the housing 45 (Fig. 8). Se-

cured to the inwardly projecting surface of member 90-'is an extending ridge or ward 91 which is adapted to register in the space between the key cams 92 and 93 as indicated" in the dashed position in Fig. 9, provided on the locking mechanism 46, the ward 91 passing throughan' appropri ate keyhole plate 94 secured within the housing 45. The ward 91 will only register properly within the'space='be'-- tween the cams 92 and 93 'when the trigger arm 88 is in In any other position, the ward' 91" will abut the outer surface of cam 93 to prevent the'closing and sealing of the cover 52'. Withthe cover SZ'Cprovided with a projecting ridge or-ward as 'described'and"'- the cover closed,the trigger arm will be held in-its' locked Should the cover 52'be open andthe-trigger its locked position.

position. arm rotated, the cover cannot be closed and sealed until the trigger arm is restored toits proper position. i

The latchout mechanism as herein described may be used advantageously on various forms of electric'locks. With a latchout mechanism of the character described; the authorized or unauthorized use of the emergency k'ey release of the electric lock will provide'a tell-tale either by way of setting a restrictive signal for traffic 'moving over the protected switch, or by other changes in the particular control circuits used, which may only be reset to normal by a maintainer equipped with the proper pad lock key. Delays in moving traffic over such a protected switch are also reduced to a minimum in that the electric lock latch mechanism may be padlocked in its locked position after the hand-throw lever has been restoredft'oits normal position by a trainman without waiting'for the" arrival of the maintainer to reset the latchout mechanism; I The additional safeguard provided by the ridge or on the emergency release cover is also advantageous 'iir that proper relation of the latchout mechanism Withthe' emergency key release is at all times maintained and as A sured.

key release for an electric lock embodying our invention,

In this case, the latch 9 it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from thespirit and scope of our invention.

Having thus described our invention, what we claim is:

1. A latchout mechanism for a member movable from a locked position to an unlocked position, said member being prevented from being moved to its unlocked position by a locking dog positioned in its path, comprising, release means for moving the locking dog out of the path of the movable member, a latch member movable behind said movable member in its unlocked position to prevent the return of said movable member to its locked position, and means operatively connected to said release means for tripping said latch member upon operation of said release means to permit movement of the latch member behind said movable member.

2. A latchout mechanism for a member movable from a locked position to an unlocked position, said member being prevented from beingmoved to its unlocked position by a locking dog positioned in its path, comprising, release means for moving the locking dog out of the path of the movable member, a latch member biased for movement into the path of movement of said movable member, means for holding said latch member out of the path of said movable member, and means operatively connected to said release means for tripping said latch member upon operation of said release means, said latch member when tripped abutting said movable member in its locked position, the movement of the movable member to its unlocked position after the locking dog is moved out of its path by the release means permitting the latch member to be moved behind said movable member to prevent the return thereof to its locked position.

3. A latchout mechanism for a member movable from a locked position to an unlocked position, said member being prevented from being moved to its unlocked position by a locking dog positioned in its path, comprising, release means movable from an inoperative position to an operative position for moving the locking dog out of the path of the movable member when the release means is moved to its operative position, a latch member movable behind said movable member in its unlocked position to prevent the return of said movable member to its locked position, means operatively connected with said release means for tripping said latch member upon initiating the movement of the release means from its inoperative to its operative position to permit movement of the latch member behind the movable member, and a locking element movable into and out of engagement with said release means, said locking element being movable into engagement with said release means only when said release means and tripping means are in their inoperative positions, said locking element when in engagement With said release means preventing movement of the release means and tripping means to their operative positions.

4. A latchout mechanism for a member movable from a locked position to an unlocked position, said member being prevented from being moved to its unlocked position by a locking dog positioned in its path, comprising, release means movable between an inoperative and operative position for moving the locking dog out of the path of the movable member when said release means ismoved to its operative position, a latch member biased for movement into the path of movement of the movable member, means for holding said latch member out of the path of said movable member, means operatively connected to said release means for trippinpg said latch member upon initiating the movement of said release means to its operative position, said latch member when tripped abutting the movable member in its locked position, the movement of the movable member to its unlocked position upon withdrawal of the locking dog by the release means from me path of movement of the movable member permitting 10 the latch member to be moved behind the movable member to prevent the return thereof to its locked position, and a locking element movable into and out of engagement with said release means, said locking element being movable into engagement with said release means only when said release means and connected tripping means are in their inoperative positions, said element when in engagement with said release means preventing the movement of said release means and tripping means to their operative positions.

5. A latchout mechanism for a member movable from a locked position to an unlocked position, said member being prevented from being moved to its unlocked position by a locking dog positioned in its path, comprising, release means for moving the locking dog out of the path of the movable member, a latch member movable behind said movable member in its unlocked position to prevent the return of said movable member to its locked position,

means operatively connected to said release means for tripping said latch member upon operation of said release means to permit movement of the latch member behind said movable member, and control elements actuated by said movable member in moving from its locked position to its unlocked position, said control elements remaining actuated as long as said movable member is in its unlocked position.

6. A latchout mechanism for a member movable from a locked position to an unlocked position, said member being prevented from being moved to its unlocked position by a locking dog positioned in its path, comprising, release means for moving the locking dog out of the path of the movable member, a latch member biased for movement into the path of movement of said movable member, means for holding said latch member out of the path of said movable member, means operatively connected to said release means for tripping said latch member upon operation of said release means, said latch member when tripped abutting said movable member in its locked position, the movement of the movable member to its unlocked position after the locking dog is moved out of its path by the release means permitting the latch member to be moved behind said movable member to prevent the return thereof to its locked position, and control elements actuated by said movable member in moving from its locked position to its unlocked position, said control elements remaining actuated as long as said movable member is in its unlocked position.

7. A latchout mechanism for a member movable from a locked position to an unlocked position, said member being prevented from being moved to its unlocked position by a locking dog positioned in its path, comprising, release means movable between an inoperative and operative position for moving the locking dog out of the path of the movable member when said release means is moved to its operative position, a latch member biased for movement into the path of movement of the movable member, means for holding said latch ember out of the path of said movable member, means operatively connected to said release means for tripping said latch member upon initiating the movement of said release means to its operative position, said latch member when tripped abutting the movable member in its locked position, the movement of the movable member to its unlocked position upon withdrawal of the locking dog by the release means from the path of movement of the movable member permitting the latch member to be moved behind the movable member to prevent the return thereof to its locked position, control elements actuated by said movable member in moving from its locked position torits unlocked position, said control elements remaining actuated as long as said movable member is in its unlocked position, and a locking element movable into and out of engagement with said release means, said locking element being movable into engagement with said release means only when said release means and connected tripping means are in their inoperative positions, said element when in. engagement with said release means preventing the movement of said release means and tripping means to their operative positions.

8. In. combination with a throw lever operatively connected with a switch operating mechanism and operable between two extreme positions in one of which positions said lever is locked to prevent operation of the switch operating mechanism, a lock device having a latch member for locking said lever and movable from an intermediatelatched position to an extreme latched position and'an extreme unlatched position, means for locking said latch member in its extreme latched position, a member movable from an intermediate position to extreme'locking and lunlockingtpositions, means resiliently interconnecting said movable member and said latch member and permitting relative movement between said members, said means biasing said movable-member and said latch member to their intermediate positionslwhen said locking means is unlocked, electrical control elements actuated when said-movable member is in its intermediate and unlocked positions, a locking dog inthe path of the movable member to prevent movement of said movable and latch members from their intermediate positions to their respective unlocked and unlatched positions, key operated 'means for moving said locking dog out of the path of said movable-member, a latching bar biased for movement into the path-of said'movable member, and means forming a part of said key operated'means fortripping said latching bar upon initiatingthe operation ofsaid key operated means, said latching bar after tripping being biased against said movable member in its locked and intermediate positions, the movement of said movable member to its unlocked position by the latch member permitting the latching bar to move into the path behind the movable member'to hold the movable member against return to its intermediate and locked positions, the resilient interconnecting means permitting the return of the latch member to its latching position to lock the throw lever against movement, the actuated electrical control elements providing a tell-tale that the key operated means was operated.

9.' In combination with'a throw lever operatively connected with a switch operating mechanism and operable between two extreme positions in one of which positions said lever is locked to prevent operation of the switch operating mechanism, a lock device having a latch member for locking said lever and movable from an intermediate latched position to an extreme latched position and an extreme unlatched position, means for locking said latch member in its extreme latched position, a member movable from an intermediate position to extreme locking and unlocking positions, means resiliently interconnecting said movable member and said latch member and permitting relative movement between said member, said means biasing said movable member and said latch member to their intermediate positions when said locking means is unlocked, a locking dog in the path of the movable member to prevent movement of said movable and latch members from their intermediate positions to their respective unlocked and unlatched positions, electrically operated means for moving said locking dog out of the path of said movable member, key operated means for moving said locking dog out of the path of said movable member, a latching bar biased for movement into the path of saidmo-vable member, and means forming a part of said -key operated means for tripping said latching bar upon initiating the operation of said key operated means, said latching bar after tripping being biased against said movable member in its locked and intermediate positions,- the movement of said movable member to its unlocked'position by the latch member permitting the latching barto move into the path behind the movable memberto hold the movable member against return to its intermediate and locked positions, the resilient interconnecting means permitting the return of the latch member to'its latching position to lock the throw lever against movement.

10. In combination with a throw lever operatively connected with avswitch operating mechanism and operable between two extreme positions in one of which positions said lever is locked to prevent operation of the switch operating mechanism, a lock device having a latch member for locking said lever and movable from an intermediate latched position to an extreme latched position and anextreme unlatched position, means for locking said latch member in its extreme latched position, a member movable from an intermediate position to extreme locking and unlocking positions, means resiliently interconnecting said movable member and said latch member. and permittingrelative movement between said member, said means biasing said movable member and said latch member to their intermediate positions when said locking means is unlocked, electrical control elements actuated when said movable member is in its intermediate and unlocked positions, a locking dog in the path of the movable member to prevent movement of said movable and latch members from their intermediate positions to their. respective unlocked and unlatched positions, electrically operated means for moving said locking dog out of the pathof said movable member, key operated means for moving said locking dog out of the path of said 'movable member, a latching bar biased for movement into the path of said movable member, and means forming a part of said'key operated means for tripping said. latching bar upon initiating the operation of said key operated means, said latching bar after tripping being biased against-said movable member in its locked and intermediate positions, the movement of said movable member to its unlocked vposition by the latch member permitting the latching bar to move into the path behind the movable member to hold the movable member against returntto its intermediate and locked positions, the resilient interconnecting means permitting the return of the latch'member to its latching position to lock the throw lever'against movement, the actuated electrical control elements providing a tell-tale that the key operated means wasoperated.

References Cited in the file of this patent UNITED STATES PATENTS Langdon Aug. 28, 1951

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