US1946364A - Key-permutation lock - Google Patents

Description

4 Feb. 6, 1934.

B. c. SMITH KEY PERMUTATION LOCK Filed Dec 6, 1932 2 Sheets-Sheetv l- 3 70 Bernard EEmflh. P

W V ,wfiflww Feb. 1934.

B. c. SMITH KEY PERMUTATION LOCK 2 Sheets-Sheet. 2

Filed Dec. 6. 1932 ATTORNEYS.

Patented at. 6,1934

UNITED STATES-PATENT OFFICE KEY-PERMUTATION LOCK Bernard C. Smith, Long Island City, N. Y. Application December 6, 1932. Serial No. 645,986 12 Claims. (01. 70-53) The present invention relates to improvements in locks and the primary object of the invention resides in the provision of a lock embodying key operated lock mechanism, and permutation or combination lock mechanism. automatically tripped upon unauthorized tampering with the lock to prevent operation of the key operated lock mechanism even by use of the proper key, until the permutation lock mechanism has been prop- 1o erly reset by one knowing the combination, and which resetting of the combination may then only be accomplished through aid of the proper key for the lock.

A further object of the invention is to provide a key-permutation lock embodying trip means for automatically rendering the lock inoperative unless operated by the proper key.

' A further object of the invention is to provide a key-permutation lock wherein the permutation lock mechanism acts to prevent operation of the key operated lock mechanism in event of tampering with the lock.

A further object resides in the novel arrangement whereby thepermutation lock mechanism is automatically tripped through attempted operation of the key operatedlock mechanism.

A still further object of the invention is to provide a combined key-permutation steering wheel and ignition lock wherein a single key acts to unlock the steering wheel and actuate an ignition switch. I

Other objects and advantages of the invention will be apparent during the course of the following detailed description, taken in connection with the accompanying drawings forming a part of this specification and in which drawings:-

Figure 1 is a face plan view of the lock.

Figure 2 is a side view of the lock.

Figure 3 is an enlarged view showing the cover plate removed and parts in section, the view showing the lock attached to a steering column and the locking bolt projected. Figurei is a fragmentary detail view showing the tripper raised when the key is rotated through ninety degrees from the posit-ion shown in Figure 3.

Figure 5 is a view substantially similar to Figure 3 but showing the lock bolt retracted.

Figure 6 is .a view substantially similar to Figure 3 and showing the tripper raised for tripping the permutation lock mechanism and preventing retraction of the lock bolt.

' Figure '7 is a plan view of a key for the lock.

Figures 8 and 9 are enlarged sections substan- 55 tially on the respective lines in Figure 3.

- ignition switch on theline 11--11 of Figure 8.

Figure 10 is an enlarged horizontal section substantiallyon the line 10-10 of Figure 3.

Figure 11 is a longitudinal section through the Referring to the drawings in detail and wherein similar reference characters designate corresponding parts throughout the several views, the improved key-permutation lock comprises a lock casing or housing A enclosing the key operated lock mechanism B and permutation lock mechanism C. The letter D designates an ignition switch carried by the casing A to be actuated by a key when inserted into the casing for operating the key operated lock mechanism B.

The casing A is preferably of flat, circular formation and embodies the tubular or ring-like body portion 5 closed at its rear end by the rear disk-shaped cover plate 6 and at its front end or side by theface cover plate 7. Theplates 6 and '7 may be secured to thebody portion 5 by suitable rivets or the like 8.

The letter E may designate the tubular shell or casing of a steering column of a motor vehicle having a steering post or shaft F rotatable therein. The letter G designates a suitable form of bracket for rigidly securing'the lock casing A to the shell E. Y

The key operated lock mechanism B is preferably arranged in the lower portion of the casing A and embodies a segmentalshaped slide block 9 which may be secured to the rear cover plate Gas by one or more fasteningrivets 9. The upper straight side of theblock 9 provides a sliding surface for alock bolt 10 which slidably projects through a preferably square opening 11 in thetubular body portion 5. The body portion of thislock bolt 10 is preferably square shaped in cross section to prevent rotation of the bolt. The lower side of theopening 11 is in alignment with the upper slide surface of theblock 9, while the inner surface of therear cover plate 6 preferably forms one wall of theopening 11 as shown in Figure 10. The inner end of thelock bolt 10 is preferably reduced to the width of theblock 9 and formed with anupstanding stop shoulder 12. 9 Slidable upon the upper edge of theslide block 9 is atumbler block 13 for retracting thelock bolt 10 by means of akey 14. Thetumbler block 13, adjacent its lock bolt end is recessed as at 14 providing an opening for receiving thestop shoulder 12. This recessed end of the tumbler block is formed with adownturned stop shoulder 15 against which thestop shoulder 12 abuts to limit outward movement of the lock bolt. Projecting upwardly into the recess 14' and preferably formed integral with theslide block 9 is astop 16 against which the tumbler block abuts for limiting movement of the tumbler block by anexpansion coil spring 17 acting between thestop 16 andshoulder 12. By observing Figures 3 and 6 it will be seen that thespring 17 acts to normally project thelock bolt 10. Aguide pin 18 serves to retain the forward portion of thetumbler block 13 against upward movement, while a preferably rectangular-shapedretaining stud 19, projecting inwardly from therear cover plate 6, acts to slidably retain the rear end portion of the tumbler block against upward movement. Thetumbler block 13 is provided adjacent its rear end and in its front face with atransverse guide groove 20 opening at the upper and lower edges of the block. Theblock 13 is provided at the lower end of theguide groove 20 with a substantially quadrant-shaped recess 21 providing a keyengaging edge 22 having at its lower end aprojection 23. Theslide block 9 is provided in its upper edge with asemi-circular recess 24 which aligns with a key barrel or plug 25 rotatably mounted upon the inner side of theface cover plate 7. Thecover plate 7 is provided with akeyway 26 adapted to align with akeyway 26 formed through thebarrel 25.

Slidably guided at its lower portion in theguide groove 20 is a combined latch andtrip member 28 provided with a right angularly extendingkeeper arm 29 having at its outer end adownturned lug 30 adapted to co-act with theretaining stud 19 for holding thetumbler block 13 against longitudinal movement. This down-v turnedlug 30, through engagement with the upper surface of theblock 13 also acts to limit downward movement of themember 28 in thegroove 20. As will be observed in Figures 8 and 10, thegroove 20 extends for one-half the thickness of theblock 13. As will also be noted in Figures 8 and 10, abracket 31, preferably carried by theface cover plate 7, serves to slidably retain themember 28 in thegroove 20 and thetumbler block 13 in sliding engagement against therear cover plate 6. Arib 32 on therear cover plate 6 provides a guide for the upper extremity of the combined latch andtrip member 28. v

The stem or shank portion of thekey 14 is provided adjacent its ends withbittings 33 providing terminal lugs 34. The stem of the key may also be formed with longitudinal grooves 35 for receiving suitable wards formed in thekeyway 26 of thekey barrel 25. Thebittings 33 are formed of unequal depth at the opposi e edges of the key stem so that the key will not operate the lock mechanism B unless properly inserted in the look.

In operating the lock mechanism B through use of a proper key, the key is inserted through the key-ways 26 and 26' until the key abuts therear cover plate 6 and at which time thenotches 36 in the key stem so align with theface cover plate 7 as to permit rotation of the key. The position of the key when first inserted into the lock is shown in Figure 3. The key is then rotated in a clockwise direction and when rotated through ninety degrees to a position as shown in Figure 4, the combined latch andtrip member 28 is raised sufficiently to allow thelug 30 to clear theretaining stud 19. It will be noted that themember 28 is raised through engagement with the base of one of thebit ings 33 and the depth of this bitting determines the proper height that themember 28 may be raised to clear theretaining stud 19 and yet not trip the permutation lock mechanism C. As the key is turned for its limit of movement in a clockwise direction, one of the terminal lugs 34 on the key engages the inclined keyengaging edge 22 of thetumbler block 13 and shifts the block in a direction for retracting thelock bolt 10, As theblock 13 is shifted, thelatch member 28 is permitted to lower as in Figure 5 so that thelug 30 engages behind the retaining stud l9 and thus latches the lock bolt against being accidentally projected. Theprojection 23 limits rotation of the key in a lock opening direction and from Figure 5 it will be seen that the key is not rotated through 180 for operating the look so that the key is held against being withdrawn from the look when in an unlocked condition. The key is held against withdrawal by the notches 86 receiving the reduced portion of theface cover plate 7 at thekey barrel 25. As thetumbler block 13 is moved by the key, theshoulder 15 acts upon thestop shoulder 12 to retract thelock bolt 10 and compress thecoil spring 17. When the key is turned in a counter clockwise direction for the locking operation, the key acts to lift thelatch member 28 and free thelug 30 from the retainingstud 19 and after which thespring 17 acts to project thelock bolt 10 and through theshoulders 12 and 15 return thetumbler block 13 to the position as in Figure 3.

Thelock bolt 10 slidably extends through an opening in the steering column casing E and is intended to have its outer end engage in abolt receiving opening 38 provided in the steering shaft F when theopening 38 is properly aligned with thelock bolt 10. Theopening 38 is preferably arranged to align with thelock bolt 10 when the vehicle wheels are in a straight forward position. Should the lock be operated with the vehicle wheels turned to either side so that theopening 38 does not align with thelock bolt 10, thespring 17 acting to normally project the lock bolt, holds the bolt in engagement with the circumferential face of the steering shaft so that the bolt will enter theopening 38 when the steering shaft is rotated to a straight forward position. Thus it will be seen that it is not essential to have the steering Wheels in a straight forward position at the time the lock is operated for locking the steering wheel.

Referring now to the permutation lock mechanism C, the same is preferably arranged in the upper portion of the lock casing and embodies a mountingspindle 40 having aflange 41 at its rear end for rigid attachment to therear cover plate 6. Rotatable upon the forward end of thespindle 40 is asleeve 42 which projects through an opening in theface cover plate 7 and has secured thereto adial plate 43 provided with suitable numbers or letters for co-acting with a marking provided on the face cover plate. Secured against too rotation upon thesleeve 42 at the inner side of 335 thecover plate 7 is amaster tumbler disc 44 which co-acts with thedial plate 43 to prevent axial movement of the sleeve. Freely rotatable upon thespindle 40 at the inner end of thesleeve 42 is atumbler disc 45 having provided in its peripheral edge a notch orrecess 46. Thesleeve 42 acts to space thediscs 44 and 45.' Pivotally mounted intermediate its ends upon thespindle 40 between theflange 41 andtumbler disc 45 is a lockinglever 47 adapted for swinging movement upon actua ion of thetumbler block 13. Thelower arm 48 of the lockinglever 47 projects into aslot 49 formed in the face side of thetumbler block 13. Theupper arm 50 of the locking lever is provided with a forwardly and right angularly offsetend portion 51.

Pivotally mounted in the upper portion of the casing A as upon asuitable stud 52 carried by therear cover plate 6, is a pivoted lockingpawl 53 of L-shape and providing ahead portion 54 adapted toengage in the notch orrecess 46 provided in the peripheral edge of thetumbler disc 45. Thehead portion 54 of the lockingpawl 53 is intended for swinging movement into and out of the path of swinging movement of the offsetend portion 51 of the lockinglever 47 to prevent actuation of the slidingtumbler block 13.

Extended through the peripheral portion of thetumbler disc 45 to project laterally from each face thereof is a pin or stud providing atrip pin portion 56 projecting from the rear face of the disc and a setting pin portion 5'7 projecting from the forward face of the disc. Projecting rearwardly from themaster tumbler disc 44 is a pin orstud 58 which upon rotation of the master tumbler disc engages thesetting pin portion 57 for imparting rotation to thetumbler disc 45.

The upper end of the body portion of the combined latch andtrip member 28 extends at the rear ofthetumbler disc 45 as shown in Figure 8 and is provided at its upper extremity with a forwardly extending, right angularly off-set looking arm orextension 60 adapted to engage in asuitable notch 61 provided in the peripheral edge of themaster tumbler disc 44.

Projecting forwardly from the upper portion of therear cover plate 6 is apin 62 having an annularly recessed intermediate portion for receiving the convolutions of a spring so coiled upon the pin as to providespring arms 63 and 64 for respectively engaging the lockingpawl 53 and thelocking arm extension 60 of thetrip member 28. As will be observed, thespring arm 63 acts to normally urge thehead portion 54 of the lockingpawl 53 against the peripheral edge of thetumbler disc 45, while thespring arm 64 acts to normally urge themember 28 downward for forcing the lockingextension 60 against the peripheral edge of themaster tumbler disc 44 and thekeeper arm lug 30 into engagement with the upper edge of thetumbler block 13. It will be noted that thetumbler disc 45 is of less diameter than that of themaster tumbler disc 44 to allowfor'the locking arm 60 to properly engage in thenotch 61.

The upper portion of thetrip member 28 is notched out at its edge confronting thespindle 40 as at 66 and provides atrip shoulder 67. Thisrecess 66 accommodates thetrip pin portion 56 of thetumbler disc 45 and is of such length as to permit movement of thetrip member 28, when operated by the proper key, without tripping the permutation lock mechanism C. As shown in Figure 4, when thetrip member 28 is raised for the proper distance through use.of the proper key, thetrip shoulder 67 has just contacted thetrip pin 56 without imparting any rotation to thetumbler disc 45. Should thetrip member 28 be lifted beyond the position shown in Figure 4 by some one endeavoring to operate the lock, and say to a position as shown in Figure 6, thetrip shoulder 67 through engagement with thetrip pin 56 will impart' rotation to thetumbler disc 45 in an anti-clockwise direction thus raising the lockingpawl 53 out of therecess 46 so that thehead portion 54 rides upon the peripheral surface of the tumbler disc. In this position, thehead 54 is moved into the path of swinging movement of the offsetend 51 of the axis slightly below the axis of thekey barrel 25.

Formed longitudinally through theswitch body 70 is a pair of terminal receiving openings '71 which are reduced in diameter at the attaching end of the switch body to provide shoulders for the heads of attaching screws '72 extended through therear cover plate 6 and preferably threaded into theslide block 9. This manner of attaching the switch body to the lock casing permits ready separation of the switch from the lock for repairing the switch without requiring dismembering of the lock. Formed axially through the switch body '70 and terminating just inwardly of the outer end of the body is acircular bore 73 to slidably receive a,plunger 74 formed of any suitable insulating material. Thisplunger 74 is slidable through an opening '75 in therear cover plate 6 and extends through therecess 24 in theslide block 9 just below thetumbler block 13. Anexpansion coil spring 76 arranged in the closed end of the bore '73, acts upon theplunger 74 to normally urge the plunger into the lock casing A into abutting engagement with the inner end of thekey barrel 25. As will be observed in Figure 8, theplunger 74 projects over thekeyway 26 so that when the key is inserted, the key will force the plunger into the switch body '70 against the action of the spring '76.

Recessed into the rear end portion of the plunger '74 is a metallic contact sleeve 77 adapted to be engaged by spring urged contacts '18. The openings 71 receiveterminal wires 79 provided witht ps 80 held against displacement by suitable set screws 81. Thetips 80 are preferab'y recessed to receive the set screws 81. When the plunger '74 is projected into the lock casing as in Figure 8, the metal contact sleeve 77 is out of bridging relation between the contacts 78. When a key is inserted for operating the lock, the key acts to force theplunger 74 into the position shown in Figure 11 so that the contact sleeve '77 bridges the contacts 78. When the key is rotated for lock ng the lock, thespring 76 acting upon theplunger 74 serves to eject the key from the lock and eliminates possibility of the operator leaving the key in the look.

In operation of the. key-permutation lock, and with the lock in a cond tion as shown in Figure 3, it will first be noted that themaster tumbler disc 44 is locked against rotation through engagement of the lockingarm 60 in theperipheral notch 61 of the master tumbler disc. When the proper key is inserted into the lock and rotated in a clockwise direction, the combined latch andtrip member 28 is raised so that thelug 30 clears thestud 19 and after which themember 28 andtumber block 13 are moved as a unit for retracting the lock bo't 10. The proper key raises thetr p member 28 for such an extent that thetrip shoulder 67 just engages thetrip pin 56 without imparting rotation to thetumbler disc 45. So long as the lockingpawl 53 remains in thenotch 46 of thetumbler disc 45, the lockinglever 47 may swing as shown in Figure 5. When thelock bolt 10 is fully retracted thelug 30 engages behind the retainingstud 19 and holds the lock bolt against being accidentally projected.

Now, should an attempt be made by an unauthorized person to operate the lock, it will first be noted that thedial plate 43 is locked against rotation. Should an attempt be made to operate the look by use of an improper key or an instrument inserted through thekey barrel 25, the combined latch andtrip member 28 must first be raised to permit any movement being imparted to thetumbler block 13. Should themember 28 be raised slightly above a point of I its proper operating position, thetrip shoulder 67 so engages thetrip pin 56 as to rotate thetumbler disc 45 thus raising the lockingpawl 53 out of thenotch 46 and into the path of swinging movement of the lockinglever 47. Thus, the key operated lock mechanism is locked against operation. With the lock in this condition, it will not be possible to operate the lock even through use of the proper key and the permutation lock mechanism must be set by the person knowning the proper combination. It may here be well to state that thedial plate 43 not required to be operated for opening the look by the key 14 and is only used in case the lock has been tampered with so as to trip the permutation lock mechanism.

In resetting the lock for proper operation from a condition of the lock as shown in Figure 6, the proper key is first inserted and rotated ninety degrees to the position in Figure 4 for raising thelocking arm extension 60 out of thenotch 61 to permit rotation of themaster tumbler disc 44 by thedial 43. Themaster tumbler disc 44 is then rotated in a clockwise direction whereby itspin 58 will engage thesetting pin 57 of the trippingtumbler disc 45. Continued rotation of thedisc 44 in a clockwise direction until the proper number on thedial plate 43 aligns with the arrow on theface cover plate 7, rotates thedisc 45 to an extent whereby thehead 54 of the lockingpawl 53 drops into thenotch 46. This disposes thetrip pin 56 in proper relation to thetrip member 28. Themaster tumbler'disc 44 is then rotated in an anti-clockwise direction until the proper number on thedial plate 43 is reached, which places thenotch 61 in proper position for receiving thelocking arm extension 60 when thetrip member 28 is lowered.

While the lock has been shown and described as a combined steering wheel and ignition lock, it

will readily be apparent that the ignition switch may be dispensed with if so desired, and that the lock may be used for various other purposes than that of preventing rotation of a steering shaft.

From the foregoing it will be apparent that an improved form of key-permutation lock has been provided embodying a novel arrangement whereby the key operated lock mechanism will be antomatically locked against operation through a trip mechanismincluding permutation lock mechanism which must be properly reset to permit operation of the key operated lock mechanism. It will further be apparent that an improved key-permutation lock has been provided wherein the permutation lock mechanism only serves to prevent operation of the key operated lock mechanism upon attempted unauthorized operation of the lock.

Changes in detail may be made to the form of invention herein shown and described, without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. A lock comprising key operated lock mechanism, permutation lock mechanism for prevent ing actuation of the key operated lock mechanism, tripmeans for automatically tripping the permutation lock mechanism by the key operated lock mechanism, and means actuated through tripping of the permutation lock mechanism to lock the key operated lock mechanism against movement.

2. A lock comprising key. operated lock mechanism, permutation lock mechainsm, means for tripping the permutation lock mechanism upon operation of the key operated lock mechanism, and locking means actuated through tripping of the permutation lock mechanism to prevent opertion of the key operated lock mechanism.

3. A lock comprising in combination, key operated lock mechanism embodying a movable trip member, permutation lock mechanism normally inactive upon operation of the key operated lock mechanism and tripped by said trip member when the member is moved beyond a point of its proper operating position, a locking lever movable with the key operated lock mechanism, and means for locking said lever against movement upon tripping of the permutation lock mechanism.

4. In a lock of the class described, the combination of a casing, key operated lock mechanism in the casing including a sliding tumbler, a combined latch and trip member movable with the tumbler, permutation lock mechanism in the casing embodying a tumbler disc, a locking lever movable by the sliding tumbler, a locking pawl engaging the tumbler disc and normally out of the path of movement of the locking lever, and means for tripping the tumbler disc upon movement of the combined latch and trip member beyond a point of its proper operating position whereby the locking pawl moves to a position preventing movement of the locking lever.

5. In a lock of the class described, the combination of a casing, key operated lock mechanism in the casing including a tumbler block and a combined latch and trip member movable with and slidable in the tumbler block, permutation lock mechanism in the casing including a tumbler disc having a trip pin, a,locking lever pivoted intermediate its ends in the casing with one end engaging the tumbler block for imparting swinging movement to the lever upon movement of the tumbler block, a pivoted locking pawl coacting with the tumbler disc and movable into the path of movement of the opposite end of the locking lever when the tumbler disc is rotated through engagement of the combined latch and trip member with said trip pin, and spring means normally urging the locking pawl into engagement with the tumbler disc.

6..In a lock of the class described, the combination of a casing, a key actuated tumbler in the casing, a lock bolt movable by the key actuated tumbler, a key actuated trip member movable with and in the key actuated tumbler, a tumbler disc rotatable in the casing and having a notch provided in its peripheral edge, a trip pin on the disc, a locking lever pivoted intermediate its ends in the casing, said lever having one end engaging in the key actuated tumbler for swinging the lever and having an offset stop portion at its opposite end, a locking pawl pivoted in the casing and normally seating in the notch in the tumbler disc, and a trip shoulder formed on the trip member to engage said trip pin and rotate the tumbler disc whereby the locking pawl forms an abutment for the ofiset stop portion of the locking lever to prevent movement of said key actuated tumbler to retract the lock bolt.

7. In a lock of the class described, the combination of a casing, a tumbler slidable in the casing and having a transverse guide groove, a lock boltretractable by the tumbler, a combined latch and trip member slidable in the guide groove embodying a keeper arm and a trip portion, a spindle mounted in the casing, a-locking lever intermediately pivoted upon ing one end interlocked with the tumbler and having a stop projection at its opposite end, a tumbler disc rotatable on the spindle and having a recess provided in its peripheral edge, a trip pin carried by the tumbler disc and engageable by the trip portion of the combined latch and trip member for imparting rotation to the tumbler disc, a locking pawl pivoted in the casing and having a head portion for seating in the recess in the tumbler disc, said head portion upon rotation of the tumbler disc to rise out of the recess and into the path of movement of the stop projection on the locking lever to prevent swinging thereof, and means for returning the tumbler disc to a position with the head portion of the locking pawl seating in the recess of the tumbler disc.

B. In a lock of the class described, the combination of a casing, a tumbler slidable in the casing andhaving a transverse guide groove, a combined latch and trip member slidable in the guide groove embodying a keeper arm and a trip portion, a locking extension on the trip portion, a lock bolt movable by the tumbler, a spindle ,mounted in the casing, a tumbler disc rotatable on the spindle and having arecess in its peripheral edge, a stop pin on the tumbler disc engageable by the trip portion of the combined latch and trip member, a locking lever pivoted upon the spindle and having an arm interlocked with the tumbler for imparting swinging movement to the lever, a locking pawl co-acting with the peripheral edge .of the tumbler disc and the recess therein for locking the locking lever against movement when the pawl rides out of said recess, a master tumbler disc rotatable on the spindle and having a notch in its peripheral edge for receiving said locking extension, means for rotating the master tumbler disc, setting pins on the discs for imparting rotation to the tumbler disc upon rotation of the master tumbler and spring means acting upon the locking pawl and the combined latch and trip member for normally urging the'same into engagement with their respective tumbler discs.

9. In a lock embodying key operated lock mechanism including a latch member, a locking lever rotated upon operation lock mechanism, and permutation trip means normal operation,

the spindle and hav-" of the key operatedfor the lock mechanism includin a tumbler disc having a recess in its peripheral edge, a trip pin on the tumbler disc andengageable by the latch member when moved beyond its point of for imparting rotation to the tumbler disc, a locking pawlbearing upon the peripheral edge of the tumbler disc to engage in said recess, said locking pawl when moved out of the recess through rotation of the tumbler disc preventing movement of the locking lever, and resetting means for the tumbler disc to permit actuation of the key operated lock mechamsm.

10. In a lock of the class described, the combination of a. casing, a tumbler slidable in the casing, and having a transverse guide groove, a lock bolt retractable by the tumbler, a retaining stud, a latch member slidable in said guide groove and embodying a keeper arm co-acting with said stud for retaining the tumbler in either of its positions of limited movement, permutation trip means tripped upon movement of the latch member transversely of the tumbler beyond its normal position of operation, and locking means associated with the tumbler and trip means for locking the tumbler against movement upon tripping of the trip means.

11. In a lock of the class described, the combination of a casing, a tumbler slidable in the casing, .and having a transverse guide groove, a lock bolt retractable by the tumbler, a retaining stud, a latch member slidable in said guide groove and embodying a keeper arm co-acting with said stud for retaining the tumbler in either of its positions of limited movement, a locking lever pivoted for swinging movement upon operation of the tumbler, a locking pawl for the looking lever, and means for swinging the locking pawl into locking relation with the locking-lever to prevent retraction of the lock bolt by the tumbler upon movement of the latch member beyond its normal limit of movement.

12. In a lock of the class described, the combination Olf a casing, a tumbler slidable in the casing and having a transverse guide groove, a lock bolt retractable by the tumbler, a retain,- ing stud, a latch member slidable in said guide groove and embodying a keeper arm co-acting with said stud for retaining the tumbler in either of its positions of limited movement, a locking lever pivoted for swinging movement upon operation of the tumbler, a locking pawl for the locking lever, and means for swinging the locking pawl into locking relation with the locking lever to prevent retraction of thelock bolt by the tumbler upon movement of the latch member beyond its normal limit of movement including permutation resetting mechanism and the proper key for operating the lock.

BERNARD C. SMITH.

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