US 3563067 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Feb.16,1971 DHOOTE 3,563,067.
PERMUTATION PADLOCK MECHANISM Filed Feb. '7, 1969 INVE NTOR DANIEL J. FOOTE ATTORNEY United States Patent U.S. CI. 70-25 3 Claims ABSTRACT OF THE DISCLOSURE This permutation padlock contains mechanism which, following the dialing of the last number of the combination and the withdrawal of the shackle to its outer released position, will automatically turn the dial substantially away from the last dialed number thereon. The improved mechanism also includes a confined band spring engaging the shackle locking lever in a manner so as to relieve the pressure exerted on the tail of the lever resulting from the weight of the padlock body when the same is suspended from a shackle engaged hasp staple or the like, thus insuring free and proper operation of the padlock release mechanism including the dial number upset above referred to. Moreover, the locking lever tail under these conditions is maintained out of contact with the tumblers whereby a tamperer cannot feel out the positions of the tumbler gates, and thus surreptitiously, find the combination.
BACKGROUND OF THE INVENTION In many conventional permutation locks, after the lock has been opened or the shackle released the dial knob is frequently left in its last position of turning movement which designates the last number of the lock combination. Padlocks, being relatively small and compact may have their minimum number of tumblers operated by only three dial numbers. Hence, with the last number being known, as above noted, it is possible for a tamperer having knowledge of permutation locks to easily determine the first two numbers of the combination and thereby unauthorizedly operate and release the lock. With the foregoing in mind, one of the principal objectives of the present invention is to overcome the deficiency above noted by the provision of permutation padlock mechanism which, after the last number of the combination has been dialed and the padlock shackle is pulled to its released position, will automatically turn the dial a variable but substantial distance away from the last dialed number of the combination, effecting a dial number upset.
A further object of the invention is to provide permutation padlock mechanism which includes a combination disc or tumbler fast with the dial and adapted to be engaged by a pawl carried by the long leg of the padlock shackle, etfective, when the shackle is moved to its extended, released position, to turn the dial off the last number of the combination.
Another object of the invention is to provide in a permutation lock mechanism which includes a pivotal locking lever, spring means reacting against said locking lever in a manner so as to prevent, during unlocking operations, weight and gravitational forces from undesirably causing the locking lever tail to engage in tumbler gates or notches and thereby preclude proper operation of the lock mechanism including the dial number upsetting means.
As an incident of the last-mentioned object the reaction of the spring against the locking lever prevents, during certain periods, contact between the lever tail and the tumblers when the latter are turned, rendering it impossible for a tamperer to feel out the positions of the tumbler gates to unauthorizedly learn. the lock combination.
Still further objects of the invention are to provide permutation lock mechanism for the purposes set forth which is relatively simple and inexpensive, which does not interfere with the normal functioning of the conventional tumbler discs, which is automatic, and which is well adapted for the purposes set forth.
It has long been conventional in the art to provide means for upsetting a lock mechanism releasing tumbler when the shackle is pushed back into the casing, after having been released. Also, the Iunkunc Pat. No. 3,270,534 discloses means, in a combination padlock, for turning the dial ofi the last number of the: combination when the released shackle is moved to its closed position. However, applicant has no knowledge of any prior patent or patents wherein the last dial number upset or turn-off is accomplished automatically when the shackle is moved to its unlocked position free of the casing. Additionally, applicant has no knowledge of any prior patents disclosing a band spring reacting against the locking lever in the manner and for the purposes herein set forth.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings wherein the same reference characters designate the same or similar parts in all of the views:
FIG. 1 is a front face view of a permutation padlock containing the improved mechanism with a portion of the dial broken away to show internal components, the padlock shackle being in its locked position with the last number disc or tumbler having been dialed so that its gate is in position to accept the locking lever tail when the shackle is pulled toward its extended position;
FIG. 2 is a vertical sectional view taken approximately along the line 22 in FIG. 1;
FIG. 3 is a view similar to FIG. 1 only showing the padlock shackle moved toward its released position;
FIG. 4 is a sectional view taken approximately along the line 4-4 in FIG. 2;
FIG. 5 is a view similar to FIG. 4 only with the first and second tumbler disc assembly removed and showing the last number cam disc engaged by the forked pawl collar during movement of the shackle toward its released position;
FIG. 6 is a face view of the last number cam disc or tumbler;
FIG. 7 is a perspective view of the shackle locking lever and its associated band spring; and
FIG. 8 is a fragmentary perspective view of the inner end portion of the long leg of the shackle and the cam disc operating pawl collar carried thereby.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularly to the drawing it will appear that the permutation padlock mechanism includes a conventional casing 15, preferably of cylindrical form, having openings in its Wall portion to slidably receive the long leg 16 and the short leg 17 of a U-shaped shackle 18. At its inner end the long leg of the shackle is formed with an annular groove to receive a forked pawl collar 19. The inner end portion of the short leg 17 of said shackle is beveled and notched, as at 20, to disengageably receive a spring loaded plunger 21 mounted within a locking lever 22, as is common in the art, said locking lever 22 being pivotally mounted on a post 23.
The construction, mounting and functioning of the assembly which includes the first and second number tumbler discs 24 and 25, the friction disc 38 and the stud 26 whereon they are mounted is substantially similar to that disclosed in the Soref and Marshall US. Pat. No. 2,169,907, and need not be described in detail. However, concentric with said discs 24 and is a last number combination tumbler disc 33 shown in detail in FIG. 6 and which is mounted fast on a reduced and shouldered hub portion 27 of an externally accessible dialing knob 28. Said dialing knob is rotatably mounted in the front wall of the casing 15 and rigidly carries an external dial plate 29 for rotation with the knob. The front wall of the casing is formed with an annular bead 31 surounding the dial plate 29 and the bead carries an index mark (not shown) for registration with predetermined scale markings on the face of the dial plate.
The locking lever 22 is specially shaped, as shown in FIG. 7, with an eccentrically shaped cavity 32 in its under side to accommodate peripheral portions of the last number cam disc 33 when the latter is turned. Also, the outer peripheral portion of said cavity 32 is provided with an inset transverse rib 34 which forms a lever tongue for entry into the gates 35 of the tumbler discs 24, 25 and 33 under proper operational conditions. The inner face of the locking lever 22, spaced from its upper edge, is formed with a slot 36 in which is tightly imbedded an extent of a band spring 37. The latter extends in a slight curve beyond an end of said lever across the short leg 17 of the shackle 18 and yieldingly bears against an inner surface portion of the casing, as is best shown in FIGS. 4 and 5. Said spring exerts a force on the lever 22 such as will yieldingly oppose pivotal movement of the lever in a direction to contact its tail or tongue 34 with peripheral portions of the discs 24, 25 and 33.
OPERATION In the padlock embodiment illustrated three predetermined numbers are dialed in the usual manner to successively turn the discs 24, 25 and 33 so that their gates 35 will be in registry and be positioned ready to receive the locking lever tail or tongue 34. Thereafter, a further manual pull exerted on the shackle 18 moves its short leg 17 from the position of FIG. 4 to the position of FIG. 5 where the notched end 20 of said shackle leg is working free of the lever plunger 21. During such movement the force exerted by the beveled end of the shackle leg 17 will rock the lever assembly in a counterclockwise direction (relative to FIGS. 4 and 5) so that the lever tail 34 drops into the alined gates 35. When the notched end 20 of said shackle leg 16 clears the locking lever and plunger 21 but is still within the lock casing the spring 37 will be effective to move the locking lever 22 in a clockwise direction (relative to FIG. 5) and thus remove the tail 34 from the tumbler gates 35. Further outward pull exerted on the shackle 18 until the leg 17 is completely free of the lock casing will, due to the upward outward movement of the long leg 16 of the shackle, engage the pawl lug 39 on the member 19 in a notch between a pair of teeth 40 on the last number disc 33 and thereby turn said disc 33 and the knob 28 and dial plate 29 fast therewith in a clockwise direction (relative to FIG. 5) whereby the scale marking 30 last dialed will be removed an indiscriminate number of graduations away from the last dialed number, rendering it impossible for a tamperer to thus determine the last dialed number for the particular permutation padlock. When the shackle 18 is ultimately pushed back into the casing the friction plate 38 will operate to turn the innermost tumbler disc 24 away from its dialed position. The construction and operation of the friction plate 38 is similar to that illustrated and described in the Soret et a1. Pat. No. 2,169,- 907.
From the foregoing it will be seen that the improved permutation padlock mechanism incorporates simple, but elfective means for automatically turning the dial away from the last dialed number thereon when the shackle, after being unlocked, is Withdrawn to its outer position free of the lock casing. During the movement of the shackle from its innermost to its outermost position there are a sequence of operational movements as between the locking lever 22 and the discs 24, 25 and 33, particularly with respect to the gates therein. At such times the spring 37 functions and even when the Weight of the suspended lock might, without the spring, permit canting of the locking lever tail to a position of contact with the disc peripheries or their gates, the force of the spring 37 opposes such improper movements of the locking lever. Moreover, with the locking lever tail being maintained out of contact with the discs in the locked condition of the shackle, shown in FIG. 1, a tamperer is precluded from feeling out the positions of the tumbler disc gates when turning the dialing knob, to surreptitiously learn the combination and unauthorizedly release the shackle. Furthermore, the permutation padlock mechanism is free of manufacturing complications, the hereindisclosed structural features operate automatically, the mechanism renders the padlock strong and safe, and the mechanism is well adapted for the intended purposes.
What I claim is:
1. In a permutation padlock including a casing having openings therein, a dialing disc rotatably carried by the casing, a shackle having legs slidable in said openings, one of the legs being longer than the other and the short leg being formed with a latching notch, a plurality of rotatable tumbler discs formed with gates and operated by said dialing disc, one of said tumbler discs being fast with said dialing disc and having peripheral teeth, a combined locking lever and latch plunger rockingly mounted Within said casing and formed on its underside with an eccentrically shaped cavity to accommodate peripheral portions of the last-mentioned tumbler disc and with a transverse depending rib across one end of said cavity which serves as a lever tongue for entry into the tumbler disc gates, a band spring carried fast by said locking lever and extending beyond the same and into resilient contact with an inner wall portion of the casing to yieldingly resist rocking movement of the locking lever in one direction, the latch plunger portion of the locking lever being releasably engageable with the notch in the short leg of the shackle, and an upsetter pawl on the long leg of the shackle and engageable only with registering peripheral teeth on the last-mentioned tumbler disc for further turning the latter and the attached dialing disc an indiscriminate distance ofi of its last dialed position when the shackle is moved to released position with its short leg free of the casing.
2. The permutation padlock mechanism of claim 1 wherein the release of the short leg of the shackle during outward movement of the shackle is accomplished sequentially relative to the engagement of the upsetter pawl with the last-mentioned tumbler disc teeth with the upset of the dialing disc occurring during the final movement of the shackle to its fully released position.
3. In a permutation padlock including a casing having openings therein, a dialing disc rotatably carried by the casing, a shackle having legs slidable in said openings, one of the legs being longer than the other, shackle locking means in said casing including a plurality of rotatable tumbler discs operated by said dialing disc, and turnable to release said shackle, one of said tumbler discs being fast with said dialing disc, means associated with the longer leg of the shackle and engageable with the lastmentioned tumbler disc to further turn only the latter and the attached dialing disc off of its last dialed position when the shackle is moved to released position with its short leg free of the casing, and means for turning an- 6 other tumbler disc away from its dialed position when 2,931,203 4/1960 Check 70--25X the shackle is pushed back into the casing. 3,270,534 9/1966 Junkunc 7025 References Cited MARVIN A. CHAMPION, Primary Examiner UNITED ST S PATENTS 5 E. J. MCCARTHY, Assistant Examiner 2,113,864 4/1938 Soret 70-25 2,155,732 4/1939 Molinare 70-25 2,926,514 3/1960 Junkunc 70 -25X 70 -314