CA1299885C - Radiological detection resistant combination lock - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A combination lock of the type adapted for changing of the combination by a change key, a lock case housing, a stack of a plurality of tumbler wheels loosely journaled on a tumbler post for rotation about its axis and each including an annular outer rim portion and an inner annular hub portion having teeth releasably intercoupling the hub portion and rim portion at any of a plurality of relative angular positions. The rim portions of the tumbler wheels have specially shaped peripheral gates to receive confronting portions of a fence on the fence lever when the tumbler wheels are properly aligned. The tumbler post is supported within the tumbler wheel hub portions for nonrotatable axial movement to shift the hub portions axially relative to the outer rim portions between coupled and decoupled relation. An actuator is activated by rotation of the change key for axially moving the tumbler post and the tumbler wheel hub portions to shift the hub portions to decoupled relation for combination change and a secondary change fence member is moveable into inserted relation in the tumbler wheel gates and retractable therefrom upon movement the of the actuator to selectively hold the rim portion against rotation.

Description

12998~5 Il ,1 ,¦ BACKGROUND AND OBJECTS OF THE INVENTION
The present invention relates in general to combination locks, and more particularly to combination locks especially designed to resist compromise of security by detection of the opening combination of the lock through radiography or high energy radiation techniques.
Locks of the type commonly rererred to as combination locks depend for their operation upon the alignment of a plurality of disc-like rotary elements, commonly called tumbler wheeis, in a preselected manner to permit retraction of a reciprocative bolt from its projected position. Each tumbler is provided with a peripheral recess, commonly termed a gate, designed to receive a bar or fence normally disposed in overlying relation with the tumbler wheel peripheries and e~tending from a fence lever which is pivoted or otherwise coupled to a bolt and controls movement of the latter. When the tumbler gates are all disposed in registry with each other ~ and in preselected alignment with the fence, and a driving cam ¦ which effects angular adjustment of the tumbler wheels through ! lost-motion connections and controls the fence lever is adjusted to a selected angular position, the fence may drop into the tumbler gates and permit such an interconnection of the fence lever with the driving cam that limited arcuate ~ movement of the driving cam will impart movement to the fence , lever to retract the bolt. The security of such locks is ¦ dependent upon the fact that the number of orders or permu-;l tations of the possible relative positions of the tumbler '!
~ -2-!, ~29988S
.1 i gates before all of the tumbler gates come into registry with the fence to permit retraction of the bolt is so large that the chance of these gates being aligned by a person not familiar with the combination is negligible.
S In recent years, mechanical arrangements have been devised which are reasonably effective to protect the com-bination lock against mechanical manipulation thereof by unauthorized persons to surreptitiously detect the combination. However, various techniques have been developed in recent years for compromising the security of combination locks in safes and other security closures by the use of high-energy radiation. These have been variously termed radiography or radiological techniques and in general involve the production of pictures or other types of images of the lock works by photographing high-energy radiation which has passed through the lock mechanism, or by otherwise measuring such radiation emerging at various locations or for various positions of the pack G r tumbler wheels. With the I developments made in portable radiation sources, unauthorized I persons may enter on the premises containing a security container and by radiological methods determine the , combination setting of the lock and secure unauthorized entry to the protected enclosure in a short time without leaving any evidence of compromise of the lock combination.
25 I Various arrangements have been devised in an effort to protect combination locks against compromise of the combination by such radiographic techniques, including particularly the provision of radiant energy scattering ¦ devices disposed within the lock housing, especially in surrounding relation to the tumbler wheels, to effect ,1 scattering of the penetrating radiation and thereby confound l the image or photograph produced by radiological techniques.
! Examples of such radiant energy scattering devices may be found in earlier U.S. Patents Nos. 2,970,217 and 3,024,640.
S Other efforts to avoid detection by such radiographic image techniques attempting to permit observation of the angular locations of the tumbler wheel gates, with or without the presence of such radiation scattering devices, has been to form the tumbler wheels of low density materials such as nylon, rather than the metallic materials conventionally employed, to minimize the production of ~-ray or high energy radiation shadows which would reveal the positions of the tumbler wheel gates.
In addition to use of X-ray photography techniques which provide a flat photograph o' the wheel pack showing the positions of the gates, neutron beam gauging techniques or related high energy radiation measuring techniques have also been de~eloped to reveal the combination of the lock. In the ! neutron beam gauging procedure, a neutron beam from an appro-1 priate source is aimed at the edge of the tumbler wheel pack and the location of the gates is indicated on a counting device by a higher count for a set time period, which results from less metal, nylon or other material from which the tumbler wheel is made being in the beam path when the beam passes through a gate.
Some of the techniques developed to attempt to resist attack by such radiation detection procedures have included provision of additional false gates on each of the tumblers in I addition to the true gate, to confound the radiological image, or the use of additional false tumbler wheels which indicate additional combination positions other than those for the true ~Z99885 gates of the true tumbler whee],s. Another technique deve].oped is that discl,osed in the Todd U.S. Patent 3,983,727 of October 5 ".976 assigned to the United States of America as represented by the Secretary of the Army, wherein a whee], pack is used in which a novel true-fa]se gate system is provided on the perimeters of the tumb],er whee]s. The tumb].er whee]s are provided with a ].arge number of gates about the periphery of each tumbler whee], the gates being cut in the shape of right triangles and so positioned that the hypotenuse of the triangle on one side of each whee], intersects the hypotenuse of the triang],e on the other side of the whee],, and on].y one of the gates on each whee] is a true gate. The contact portion of the fence associated with these tumbler whee].s is designed to on],y contact one-ha],f of 1.5 each whee]. and is shaped so that it wi].]. on]y fit into a gate whose shape and orientation is identica], to the fence. Since a],l of the gates, whether true or fa],se, have a mirror image gate immediate].y behind them, they a]], ],ook the same in the X-ray image or the neutron counter measurement.
Whi],e combination ],ocks with the Todd type tumb],er whee], construction are effective in resisting radio].ogical detec-tion, the tumbler whee],s disc],osed in that patent are not of a construction suitab],e for effecting change of the ],ock combination. Obviously periodic changing of the combination of the ],ock by security personne]. is a usefu] and important additiona], factor in deterring unauthorized opening of the combination ].ock.
According to one aspect of the present invention, there is provided a combination ],ock of the type adapted for changing of the combination by a change key and which includes a ],ock case having front and rear wa].]s and a cylindrica]. tumbler post norma].],y extending a].ong a horizon-tal axis rearward],y from the front wa].l. A tumbler whee], stack formed of a p],ura].ity of tumb],er whee]s is ]oose],y journalled on the tumbler post for rotation about the axis thereof and each inc].uding an annu],ar outer rim portion and an inner annu].ar hub portioning formations about it periphery re],easable intercoup].ing the hub portion and the rim portion -1~99885 at any of a p]ura]ity of re]ative angu]ar positions. A
peripheral,],y gated rotatab]e driving cam is driven by a rotatab]e dia],, and means is provided for driving the tumb]er wheels responsive to rotation of the dial. and driving cam. A
fence ].ever is pivota],]y connected to a bo].t for shifting the bo]t between ],ocked and un]ocked positions, and the rim portions of the tumb],er whee],s have periphera]. gates thereon to receive therein confronting portions of a fence on the fence ],ever when the tumbler whee],s are proper]y a],igned fo],]owing dia].ing of the proper ],ock opening combination.
The rear wa],l of the ],ock case has an opening therein for insertion of a combination change key into the ],ock case and rotation thereof at a position ],ocated radia]],y outward],y of the tumbler whee],s adjacent the outer peripheries thereof.
],5 Means supports the tumb],er posts within the tumb]er whee]. hub portions for non-rotatab],y axia] movement between first and second positions and having shou],der means forward].y and rearward],y abutting the whee], hub portions of the tumb],er wheel stack for movement of the hub portions axia]],y re],ative to the outer rim portions between coup],ed and decoup],ed re]ation therewith. Rim restraint means restrain the outer rim portions against axia] movement, and tumb]er post positioning means within the lock case are activated by rotation of the change key within the ].ocked case between coup].ed and decoup]ed positions for axia], moving the tumb].er post and the tumb],er whee] hub portions to shift the tumb]er whee] hub portions to decoupled re]ati.on with the tumb],er wheel rim portions for combination change by rotation of the hub portions to new combination posi,tions re]ative to the rim portions responsive to rotation of the dia], and driving cam to a new changed ].ock opening combination. The tumb]er post position means is operative to return the tumb],er post and the tumbler whee], hub portions axia],],y to position again inner coupling the tumbler whee], hub portions and the respective rim portions responsive to rotation of the change key to coup],ed position.
According to another aspect of the present invention, there is provided a tumb]er whee] for a plura]. tumb],er whee]
- 5a -lX99885 combination ]ock capab].e of manipu].ation to change the ]ockcombination, the tumb],er whee]. inc],uding an annu]ar outer rim portion and an inner annu],ar hub portion with the outer rim portion of each tumb]er whee]. having a center opening of a diameter corresponding substantia]].y to the outer diameter of the center hub portion. The center opening of the rim portion and the outer perimeter of the hub portion have confronting substantia].],y cy]indrica] surfaces adapted to re],easab]y abut each other with the rim and hub portions in 1.0 co-p]aner alignment and interrupted by tooth formations on each of the hub and rim portions to inner fit with each other restraining the associated hub and rim against re~.ative rotation when in the co-planer norma] operating position.
The surface of the perimeter of each hub portion has a ]5 protruding ramp formation formed with a pair of inc],ined ramp surfaces converging to a crest, the ramp formation encirc]ing the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circu],ar recess therein receiving a spring member encircling the confronting hub portion and distorted from circu]ar configuration to project portions thereof from the recess into engagement with the confronting perimeter surface of the associate hub portion. The spring member engages and is disposed adjacent one inc],ined surface of the protruding ramp formation when the hub and rim portions are in norma].
operating, co-p].aner inter]ocking portion and are distorted by the ramp formations upon movement of the associated hub portion to combination change positions disp].aced from the p].ane of the associated rim portion to engage in opposite inclined portion of the ramp formation and resi]ient]y restrain the associated hub and rim portions in the combina-tion change position to provide snap action re].ative movement of the hub portion to fu].ly projected change position or to fu]ly retracted co-p]aner inter].ocked portion upon passage of the spring member over the crest.
An object of the present invention, therefore, is the provision of a nove] combination ].ock with tumb]er whee]s having hub portions or whee] centers and rim portions or whee]. cases, capab]e of being changed in their re~ative angu]ar - 5b ---- .

~299885 .
positions to each other circumferentially of each tumbler wheel to change the lock combination, and wherein the tumbler wheel gate arrangement provides true and false gates resistant I to radiation detection, and the tumbler wheels are not provided with any change key holes in the wheel or gate con-figurations which could be detected radiographically.
Another object of the present invention is the provision of a novel radiographic detection resistant combination lock construction as described in the immediately preceding para-graph, wherein novel means are provided to effect axial move-ment of the wheel centers or hub portions of the tumbler wheels making up the wheel pack is effected by means which avoid the use of a change key which would require change key holes in the tumbler wheel centers or hub portions to resist radiographic detection of tumbler wheel position by detection of key change wheel openings.
Still another object of the present invention is the pro-vision of such a combination lock construction wherein novel ! means are provided to restrain the tumbler wheel cases or rim I portions against movement during combination change movement ¦ of the tumbler wheel centers or hub portions without revealing ¦ the position of the true gates of the tumbler wheels.
Another object of the present invention is the provision of a novel radiographic detection resistant combination lock as described in the preceding paragraphs, wherein a secondary or change fence is provided, in addition to the usual fence and fence lever, together with means for axially moving the wheel centers or hub portions of the tumbler wheels, whe~ein an actuator cam structure is provided to be rotated by a I change key, associated with means which prevent change key movement of the actuator cam through a predetermined wheel hub 12g9.13~5 i disengaging range of movement when the previously existing l proper opening combination has not been dialed, but which, if ! the correct combination has been dialed, permits tumbler wheel I hub disengagement from the wheel cases during an active I portion of actuator cam movement toward the end of the range of rotation of the change key.
Still another object of the present invention is the provision of a novel tumbler wheel structure wherein the wheel centers or hub portions of the tumbler wheels are capable of ' axial movement relative to the peripheries or case portions of the tumbler wheels and spring means are provided in the wheels coactive with shaped shoulder formations to cause the hub portions and wheel perimeters to snap apart and snap together for combination changing of the wheel in a hand change wheel assembly or during assembly of the lock having key change facilities.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed l description, taken in con,unction with the accompanying draw-ings illustrating preferred embodiments of the lnvention.

i BRIEF DESCRIPTION OF T~E FIGURES
i FIGURE 1 is a perspective view of a combination lock con-structed in accordance with the present invention;
l FIGURE 2 is a horizontal longitudinal sectional view of the combination lock, taken along the line 2-2 of Fig. 1;
. FIGURE 3 is a rear elevation view of the combination lock . with the rear cover removed, showing the lock in locked condi-tion;
( YIGURE 4 is a perspective view, with part of the lock 1 case shown in section of the support plates, and secondary , fence, with the tumbler wheels and associated spacers removed;

. 7-!¦

12998~5 ¦ FIGURES 5 and 5A are top plan and elevation views .~ respectively of a tumbler wheel of the tumbler wheel pack and bottom plate, with the actuator cam and change fence removed;
FIGURE 6 is a rear elevational view of one of the tumbler wheel centers and an associated fly member;
FIGURES 7A and 7s are enlarged fragmentary section views of adjacent portions of the tumbler wheel rim members and centers and the hub encircling spring associated therewith, shown in locked position and unLocked position respectively;
FIGURE 8 is a fragmentary elevational view of the spring of Fig. 7A;
FIGURE 9 is a fragmentary perspective view of the lower tooth formation portion of the primary fence on the fence lever;
FIGURE 10 is a diagramatic rear elevational view showing the lift post member, the lift-post-moving gear member, and the sector gear member with the wheel pack, plates and other components removed to reveal these components; and FIGURES llA, llB, and llC are somewhat diagramatic, enlarged drawings of the actuator cam and adjacent portions of ¦ the secondary or change fence showing the same at normal ,¦ locking and unlocking mode positions, at the position terminating movement of the actuator cam before completion of its stroke when the prcper combination has not been dialed, and showing the parts in the combination change mode position, respectively.

129g885 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, wherein ],ike reference characters designate corresponding parts throughout the severa]. figures, there is i],],ustrated in Figs. 1-]], a combination ].ock genera].],y indicated by the reference charac-ter 20, which inc],udes a substantia],].y rectangu].ar lock case 2]. having top and bottom wa],],s 21a, 21b and means rotatab]y supporting a ho],].ow tubu]ar tumb].er post assemb],y 22, of specia], construction as hereinafter described, for rotary and axia], movement, which projects rearward].y re]ative to the front wa].], 23 of the ],ock case. A removab].e rear cover plate 21.c is provided to c],ose the rear of the lock case.
The lock case 21 is designed to be mounted against the inner surface of a safe door, file cabinet door or other security closure in the conventiona~ manner as by mounting screws extending through screw ho],es near the corners of the lock case and into the supporting door, file cabinet front wa],] or the like. Secured to the outer face of the supporting door or mounting wall concentric with the axis of the tumbler post assembly 22 is a dia], ring 24, here shown as having a cylindrical shield 24a surrounding and shie].ding from view the major portion of the periphera]. f]ange 25a of the dial.
portion 25 of the dial, and knob member 26, the shie],d 24a being interrupted by a sight opening of suitab].e circum-ferentia], extent.
The dia]. and knob member 26 is supported for rotation within the forward],y opening cylindrica]. we].]. of the dia], ring 24 defined by the shield 24a, and inc]udes a drive spind].e 27 coup].ed at its outermost end to the dia], and knob member 26 and extending through the ho]],ow tumb],er post assembly 22 on the front wal], of the ],ock case 2l., to be rotatably journa]ed by the tumb],er post assemb],y and supported at the desired position. The dia]. and knob member 26 has an integra], knob portion 26a thereon which projects forward].y from the dia].
portion 26 and preferab]y has a knurled periphery to faci~i-tate manipu],ation of the dia], and knob member 26.
The threaded rearmost end of the drive spind].e 27 receives an interna]].y threaded portion of a tubular boss formation 32a projecting forward].y integra]]y from the driving cam 32. The driving cam 32 is keyed to the drive spind],e 27 at the desired angular position by inserting a suitab],e sp],ine key into the radia]. groove in the center bore of the drive cam which is a3,igned radia].].y with a kerf in the spind],e 27 to interlock these components against further re],ative rotation. A stack or array of a p],ura].ity of tumb],er whee],s, for examp]e a four whee]. stack or a three whee]. stack, here shown as a four whee], stack, indicated by the reference characters 34, 35, 36 and 37, of special construction hereinafter described, are supported to rotate freely upon the cy].indrica] surface 22a of the ho],].ow tumb]er post assemb],y 22 extending rearward].y from the front wa]] of the lock case 21. It wi]], be appreciated, of course, that a three tumb],er whee]. stack, or a stack of any other number of tumbler whee],s may be used.
Each of the tumb],er wheels 34, 35, 36 and 37 have an inner hub or whee], center portion 38 provided with a center opening for journa].].ing the tumb].er whee] on the cy]indrica].
post assemb].y 22 and have an outer rim or "whee] case"
portion 39, which is interrelated in a specia]. way with the whee], center or hub 38 of the associated tumb],er whee], to permit combination change of the tumb].er whee]s in a nove], way and resist radiographic detection.

--],0--, ~, 1299~8S
.1 The lock is also provided with the usual bolt 40 which is ~¦ adapted to slide in a suitable guideway formed in one end of the lock case 21. The bolt 40 is operated by means of a fence ~ lever 41 which is pivotly attached to the bolt by means of a screw 42. The fence lever 41 is normally resiliently urged to the elevated position illustrated in Fig. 3 by a lever spring such as the spring 43 having, for example, one end received in the fence lever 41 and another end inserted in a hole in a stationary portion of the lock casing to resiliently urge the fence lever to rotate to the raised position. The fence lever 41 is provided with a laterally projecting bar 44, commonly referred to a fence, which is of special configuration coactive with the configuration of the peripheries of the wheel case or rim portions 39, which projects along an axis parallel to the a~is of the drive spindle 27 and overlies the peripheries of all of the tumbler wheels 34, 35, 36 and 37.
The outer wheel case or rim portions 39 of the tumbler wheels contain a specially shaped periphery defining a j plurality of gates, only one of which is a true gate, in 1 accordance with the principles disclosed in earlier U.S.
I Patent 3,983,727 to Orin Todd, granted October 5, 1976.
¦ Generally speaking, each wheel case or rim portion 39 includes an annular main body portion 45 having a shaped inwardly and outwardly directed faces 45a, 45b provided with tooth-like formations providing a plurality of gates, generally indicated at 46, extending circumferentially throughout the periphery of the wheel case with half of the gates on each wheel case or rim portion 39 being cut half way through one side of the I wheel case and the other half of the gates being cut half way ¦ through the other side of the wheel case. All of the gates 46 are cut in the shape of a right triangle and are so positioned i, -11-,j around the outer perimeter of each wheel case 39 that the hypotenuse of a triangle on one side of each wheel intersects the hypotenuse of a triangle on the other side of that wheel case.
S Similarly, the fence 44 of the fence lever 41 which must drop into a gate on each wheel case 39 to permit opening of the lock by withdrawal of the lock bolt 40 is specially shaped with adjacent pairs of shaped triangular fence teeth, such as teeth 44-a, 44-b, arranged in immediately adjacent pairs and directed in oppositely inclined relations to interfit into the shaped gates 46 of the tumbler wheel case portions 39 so that they will only contact one-half of each wheel case 39 and will only fit into a gate identical in shape and orientation to the aligned fence tooth. There is only cne gate on each wheel case that meets this requirement, and thus there is only one true gate on each wheel tumbler, while the rest of the gates form false gates. However, since all the gates, whether true or false, have a mirror image gate immediately behind them, I they all look the same on a flat X-ray plate or to a neutron ! beam counter recording the strength of a gamma neutron source, ¦ so that it is not possible to distinguish the true gates from ~¦ the false gates using X-ray or neutron sauging techniques.
More specifically, as shown in Figs. 5A and SA, the gates 46 are cut in the front and back half, in faces 4Sa, 46b of each wheel case or rim portion 39 and are so positioned relative to each other to form gate pairs 46-2, 46-3, or 46-4, 46-5, or 46-6, 46-7, as typical examples with the hypotenuse of the triangle of a gate on one side, for example 46-2, 46-4 or 46-6, intersecting the hypotenuse of the triangle of a gate .
.
l -12-1~99885 on the other side, for examp]e 46-3, 46-5, or 46-7. Whi]e the specific number of gates is not critica], it is obvious that the tota] number of gates wi],], a],ways be an even number since the gates in the back and front form gate pairs.
On].y one of the gates 46 is a true gate, as the rest are fa]se gates. The hypotenuse of the true gate goes from the edge of the whee]. case 39 in an inward],y s],anting rotation to the right whereas the hypotenuse of each of the other triangu]ar gates 46-2, 46-4, and 46-6 for examp],e, on the ].0 re]ated side of the whee], case, go from the edge of the whee]
case in inward~.y s],anting rotation to the ].eft. The hypo-tenuse of the triang],e of each of the gates 46-3, 46-5, 46-7 and so on on the other side of the whee], case, for examp],e, the rear side, a].l s].ant in the opposite direction from the 1.5 hypotenuse of the triangle of gates 46-2, 46-4, 46-6, etc., and thus each of the gates has a mirror image gate behind it.
The whee]. case or rim portions 39 of the tumb].er whee]s 34, 35, 36 and 37 and the inner hub or whee] center portions 38 thereof are provided with interfitting teeth 47, 48 designed to interfit when the whee], and center portions 39, 38 are in the a],igned or ]ocked positions shown in Fig. 7A
and to be disengaged when they are axia].].y disp],aced re]ative to each other to the un]ocked positions shown in Fig. 7B.
The inner diameter or center opening surface of the whee].
case members 39 are a]so provided with a retaining groove 39a designed to receive a spring wire 49 which forms a po],ygon with a ]arge number of sides, a part of this spring wire retainer 49 remaining exposed outside the retaining groove 39a to a],],ow for an interference fit with a ramp formation 38a on the whee], center members 38. This interference produced between the spring wire retainer 49 and the ramp formation 38a of the lX9988S

i wheel centers 38 controls the ability of the wheel center 38 to move in or out with respect to the wheel case or rim portion 39. The wheel center portions 38 are moved by applying a force sufficient to elastically deform the spring wire retainer 49 upon movement of the tumbler post assembly 22 axially to shift the wheel centers from the Figure 7A locked position to the Figure 7B unlocked position when it is desired to change the combination of the lock. The shaping of the ramp formation 38a and its interaction with the spring wire retainer 4g are such as to produce a snap action arrangement whereby, when axial force in the proper direction is applied to the wheel center while the wheel rim or case portion is held against movement, the spring w ' re retainer 49 is progressively distorted radially outwardly until it reaches the crest of the ramp formation 38a ar.d the energy stored in the spring then rapidly releases itself against the wheel hub or center portion to move it through the remainder of its allowed range of travel to the released position relative to its associated wheel rim or case portion. Similar snap action , occurs during return o~ the wheel center or hub portion to the normal interlocked relation with its associated rim or case 'I portion, which facilitates hand change of the combination of the tumbler wheel and retains the wheel center or hub portion and outer rim or case portion together as an assembly until forced sufficiently toward the released position, facilitating hand change of the wheel combination and assembly of the components in the lock mechanism assembly where key change features are provided.
The pack of tumbler wheels 34-37 are assembled together I between bottom and top plate members 51, 52 and intervening spacers 50 fixed by spacer posts 53a fixed to the bottom plate ; -14-1~98BS
,1 51 and mounting screws 53 threaded onto the front end wall 23 ¦ with the wheel case or rim portions 39 of the tllmbler wheels 34-37 retained against axial movement by the wheel spacers 50, and by the bottom plate 51 and top plate 52, assembled together in a modular arrangement. The wheel spacers 50 are provided with center openings of slightly larger diameter than the tumbler wheel centers 38 to permit relative.axial movement of the tumbler wheel centers 38 with respect to the tumbler wheel rim or case portions 39, while the spacers 50 and top and bottom plates 52, 51 restrain the wheel case or rim portions against axial movement. The spacer posts 53a and mounting screws 53 are located outwardly of the peripheries of the tumbler wheels 34-37 so that the tumbler wheels are free to rotate upon rotation of the dial and knob member 26.
The tumbler post assembly 22 provides the means for moving the wheel centers or hubs 38 axially in a direction to disengage their teeth 48 from the teeth 47 of the wheel rim or case portions 39, and comprises an axially moveable hollow tubular wheel post member 22b having a shoulder flange or 'l collar 54 near its forward end adjacent the front wall 23 of the lock case forming a lift shoulder movable in the opening 51a of the bottom plate 51 between the nearest tumbler wheel 34 and a gear member 56 for axially moving the member 22b to move the flange or collar 54 against the confronting surface of the wheel center or hub portion 38 of the nearest tumbler wheel 34. ,he wheel post member 22b has an internally threaded bore porticrl which is threaded onto the threaded stub shaft portion 55 of a gear member 56 having a short forwardly projecting cylindrical tubular portion 56a journaled in the 1 opening 23a in the front wall 23 of the lock case and extending through the bottom plate center opening 51a. The movable whee~. post member 22b a].so inc]udes a pair of diametrica]]y opposite s].ots 22c to receive diametrica]]y opposite ]ugs 51d projecting inwardly through the bottom p],ate opening 51a and s],ots 56a in gear member 56, restrain-ing the post member 22b against rotation whi].e a].].owing axia].movement thereof as the gear member 56 is rotated.
The gear member 56 serves to axia].],y move the whee]. post member 22b by the threads on portion 56a interengaging threads on the inner surface of post 22 and is rotated by a change key sector gear 57 having a stub shaft 57a projecting into a ho].e 51e of the bottom p]ate 51 and into a socket in actuator cam member 57b to journa]. gear 57 for rotation. The sector gear 57 member is located be],ow the bottom plate 5l, adjacent its associated actuator cam member 57b which has a 1,5 hol.low opening there through of square or other appropriate configuration to receive and be operated by a change key of typica]. non-round cross-section as ].ater described, and is at a ].ocation spaced outwardl.y from the periphery of the tumb].er wheels 34-37. Thus there is no change key opening in the tumbler whee].s, such as are present in conventiona] combina-tion ].ocks, by which radio],ogica]. images or measurement may be made identifying tumb]er whee]. change key openings signifying angular positions of the whee].s. The actuator cam member 57b has a finger 57c moving in slot 51e of the bottom p]ate to selectively engage shoulder surfaces 57d, 57e of gear member 57 and inc].udes a formation 57g coactive with part of a change fence 65 spaced radia]].y outward].y of the tumb]er wheels and pivoted to permit shifting of the fence 65 into and out of the true gates of the tumbler whee~s at the change mode position. The change fence 65 and actuator cam member 57b are appropriate~.y biased by spring formations 51,f and 51g on the bottom plate 5], as ]ater described.

lZ99885 Movement of the whee] center ].ift post member 22b and the engagement and disengagement of the whee] case and whee], center teeth 47, 48 is achieved by rotation of the change key gear sector member 57 through a suitab]e ang],e by finger 57c abutti.ng shou],ders 57d or 57e, causing rotation of the gear member 56 during a predetermined portion of the range of movement of cam 57b, rotating the ma],e thread on portion 56a of the gear member 56, within the fema],e threaded portion of the whee]. center lifting post member 22b. This produces axia], trans],ation of the ]ifting post member 22b and its shou],der f]ange 54 rearward]y through the bottom p],ate opening, thus forcing the tumbler whee] centers 38, the forwardmost of which bears against the ].ift f],ange 54, axia].ly rearward]y from the Fig. 7A position to the Fig. 7B
position to disengage their teeth 47, 48 so that re],ative rotation of the whee]. centers 38 re]ative to the tumb],er whee]. case or rim portions 39 can be achieved to effect combination change. The wheel, centers 38 are returned forwardly to the norma], interlocking re].ation with the rims 39 upon return of the post member 22b forwardly by rotation of gear member 56 as the washer 22d in a groove near the rearmost end of the post member 22b engages the rearmost tumb],er whee], center and moves a]], the centers forward]y.
The tumb].er whee].s 34-37 are dri,ven from the driving cam 32, spind]e 27, and the dia]. and knob member 26 which operates the spind].e 27, by means of a driving pin and f].y arrangement, wherein the driving cam has three driving pins arranged at three equa], circumferentia],],y spaced ang].es spaced different radia]. distances from the cam center, and engaging three rearward].y projecting ],ugs 59 projecting from a genera].],y circu],ar f],y 60 seated in a rearward]y facing recess or we],], in the hub portion or whee], center 38 of the rearmost -],7-; .
tumbler wheel 34 and similarly spaced different radial dis ¦ tances from the the center axis o~ the wheel centers to be engaged by a different respective one of the drive pins. The fly 60, provides the usual lost motion coupling which is well known in tumbler wheel type combination locks by having arcuate recesses 61 at three equally spaced circumferential locations which receive similarly shaped, but circumferen-tially shorter arcuate projections 62 extending from the wheel centers 38 of the forwardly adjacent tumbler wheels and received in the recesses 61. A set of three forwardly projecting drive pin lugs 63 extend forwardly from the opposite face of each wheel center 39 to engage the fly lugs 59 of the fly 60 on the next forwardly adjacent tumbler wheels 35, 36 or 37 to achieve the usual lost motion coupling drive upon appropriate rotation of the dr ~ing cam 32. This fly arrangement, employing three drive projections or drive pins and three fly lugs to be engaged thereby, instead of the usual drive pin and single fly lug on the fly, is an improvement over the conventional single point drive providing for ~ balanced forces, greater accuracy, and greater resistance to ,I wear.
To effect changing of the combination, the existing opening combination is first dialed with respect to a combination change index reference, for example as indicated at 64, rather than the normal dialing reference index. The secondary or combination change fence 65, actuated by the actuator cam member 57b rotating the gear sector member 57, ¦ has teeth 67 similar to the teeth 44a or 44b of the normal j dialing fence 44 to interfit with the true gates 46 defined by ! the right triangular tooth formations on the perimeters of the wheel case or rim portions 39 when the proper opening ~299885 combination has been dialed with respect to the change index mark 64. Upon insertion of the change key through the change key opening 68 in the rear cover of the lock case, and through , the non round opening in the actuator cam member 57b, rotation 1 of the change key through about 90 rotates the actuator cam member 57b by driving engagement of the finger 57c with shoulder 57d of gear 57, if the proper combination was dialed, after the nose 57g engaged the lower end 65a of fence 65, to , trip the change fence 65 and allow its spring 51f to propel it ! radially inwardly to interengage its teeth 67 in the true gates of the tumbler wheel case or rim portions 39 during initial movement of the change key. During the remainder of movement of the change key, the change key gear sector member 57, rotated by finger 57c, drives the gear member 56 through an appropriate arc to cause the tubular lift post member 22b to move rearwardly sufficiently to force the wheel centers 38 rearwardly relative to the wheel case or rim portions 39 held by the wheel spacers and bottom and top plates 50, 51 and 52 and disengage the teeth 47, 48 of the wheel cases 39 and 1 centers 38.
I The new or changed combination of the lock can then be dialed in the usual manner, causing the wheel centers 38 to be rotated to the new combination positions relative to their associated wheel cases 39 by the action of the driving cam 32 1 and its drive pin formations, and the flies 60 and associated lost motion coupling structure of the flies 60 and wheel centers 38, while the wheel case or rim portions 39 are held against rotation by the combination change fence 65. Upon I completion of dialing of the new combination, the change key ¦ is then rotated back to its initial insertion position, '~ causing rotation of the change key gear member 57 and gear '.1 ,1 -19-,1 !

¦ member 56 to cause the tubular lift post member 22b to return ¦ to its normal position and, through engagement of the washer 22d with the rearmost tumbler wheel center 38 of tumbler 39, returning the wheel centers 38 forwardly relative to the wheel case or rim portions 39 to reengage their teeth 47, 48 and couple them in the new combination position. During the latter part o~ the rotation of the gear member 57 and its assGciated actuator cam member 57b, the shaped projection 56b engages the forwardly proJecting lug 65b on the front side of the secondary change fence 65, pivoting the change fence 65 to its normal position withdrawing its teeth from the true gates of the tumbler wheels.
Once the combination has been set by the above described procedure, the combination lock is operated in the normal manner to open the lock in accordance with the new combination which has been set, by rotating the dial and knob member 26 first in one direction for more than four complete turns to bring the first number of the combination as indicated on the flange 25a of the dial portion 25 into alignment with the I normal dialing stationary index mark on the dial ring 24, during which the three drive pins which are circumferentially spaced and of different radial spacings from the center of the : drive cam 32 engage the fly drive lugs 59 associated with the rearmost tumbler wheel 34 and rotate that fly 60 through the lost motion arc permitted by the recesses 61 to then commence ; rotating the associated tumbler wheel 34. In similar fashion, through interaction of the driving pins 63 of wheel 34 with he fly drive lugs 59 associated with the next tumbler wheel 1 35, the tumbler wheel 35 is rotated and, through successive ~ revolutions, rotation of the tumbler wheel 36 and then the 1 tumbler wheel 37 is achieved to locate wheel 37 at its proper combination positlon. Rotation of the dial and knob member 26 I in the opposite direction through more than three revolutions to the next combination position similarly effect positioning of the tumbler wheel 36, and rotation of the knob again n the opposite direction through more than two rotations effect adju5tment of the tumbler wheel 35 to the proper position followed by final rotation o the dial again i~ the opposite direction to properly position the tumbler wheel 34. Upon return of the dial to the zero or opening position, the fence lever 41 is allowed to fall by registry of the gate of the driving cam with the nose of the fence lever, permitting the fence 44 to be lowered to a position inserting its tooth for-mations 44a into the properly aligne~ true gates on the rim portion of the tumbler wheels. Return rotation of the dial lS and knob member 26 in the opposite direction causes the fence lever nose to be cammed up out of the driving cam gate and projects the bolt 40 to the locking position. Further rotation of the dial and knob member through more than four revolutions insures scrambling of the tumbler wheels 34-37 to random nonaligned positions.
; The action of the actuator cam member 57b in relation to the tail portion 65a of the secondar~ or change fence 65 is illustrated in Figures llA, llB, and llC. Figure llA shows the parts in their normal relative position when the lock is in regular locking mode with the change fence 65 in its clockwise limit position wherein the teeth 67 thereof are spaced from and out of engagement with the peripheries 39 of the tumbler wheels. This is the relative position of the parts when the existing combination has been dialed preparatory to changing the combination of the lock. It will be noted that in this position, the nose formation 57g of the actuator cam member 57b is to the right of the proximal edge 65a' of the lower portion 65a of the secondary fence 65, and this proximal edge 65a' is in the path of movement of the formation 57h of the actuator cam 57b if one attempts to rotate the actuator cam 57b by means of a change key, when the secondary or change fence 65 has not been pivoted counterclockwise to interpose its teeth 67 in the true gates of the tumbler wheel peripheries. The actuator cam 57 is resiliently held in this position during regular operation of the lock by the lea spring formation 51g formed from the bottom plate 51. If one attempts to place the lock in a combination change condition by inserting a change key in the opening 57d therefore in the actuator cam 57b, without manipulating the lock to the unlocke& condition by dialing 'he lS combinaticn so that the true gates o. the tumbler wheels are positioned to receive the secondary or change fence teeth 67 therein, the tail formation 57h will be intercepted by the proximal corner or edge portion 65a' as illustrated in Figure llB, preventing further rotation of the change key and the actuator cam 57b through its full stroke. At the j intermediate intercept positlon of the actuator cam 57b ¦ illustrated in Figure llB, the finger 57c of the actuator cam 57b has not yet contacted the abutment shoulder 57d of the driving sector gear 57 so that the sector gear is not rotated and thus no rotation of the gear member 57 has occurred. Thus no lifting of the tumbler post 22b and no axial displacement of the tumbler wheel center or hub portions has occurred at this Figure llB intercept position of the actuator cam 57b.
If, however, the proper combination is dialed and the change key is inserted to rotate the actuator cam member 57b ! counterclockwise from the Figure llA position, the nose ; -22-¦ formation 57g when it ccntacts the proximal edge or corner 65a" of the change fence 65 trips or cocks the change fence 65 through a short range of clockwise angular movement stressing the depending leg 51f' of its associated spring arm 51f and then releasing the change fence 65 as the nose formation 57g passes from under the lower edge thereof, permitting the enerqy in the spring leg 51f' to propel the upper end portion of the change fence 65 towards the tumbler peripheries and insert the teeth 67 thereof in the true gates of the tumbler wheels. The full range of actuator cam movement to the Figure llC position is thus permitted, during the latter portion of which the finger 57c contacts the abutment shoulder 57d and rotates the drive gear sector 57 through an appropriate arch to rotate the gear member 56 a sufficient lS amount to lift the tumbler post member 22b and the tumbler wheel center or hub portions moved therewith to the release position. The new lock combination is then dialed in the usual manr.er to set the tumbler wheel hubs or centers 38 at the proper angular positions for the new combination, and the change key and the actuator cam 57b rotated thereby are then ! rotated in a return direction back to the initial insertion position of the change key, disposing the actuator cam 57b in the Figure llA position. This return rotation of the change key and actuator cam 57b, and thus of the sector gear 57 when the finger 57c contacts abutment shoulder 57e, brings projection 56b against lug 65b of the change fence 65 to rotate fence 65 and shiftits teeth 67 out of the true gates and swings the change fence 65 back to the initial, reguiar locking mode, position.

Claims (24)

1. A combination lock of the type adapted for changing of the combination by a change key, comprising a lock case having front and rear walls and a cylindrical tumbler post normally ex-tending along a horizontal axis rearwardly from said front wall, a tumbler wheel stack formed of a plurality of tumbler wheels loosely journaled on the tumbler post for rotation about the axis thereof and each including an annular outer rim portion and an inner annular hub portion having formations about its periphery releasably intercoupling the hub portion and rim portion at any of a plurality of relative angular positions, a peripherily gated rotatable driving cam driven by a rotatable dial, means for driving the tumbler wheels responsive to rotation of the dial and driving cam,a fence lever pivotally connected to a bolt for shifting the bolt between locked and unlocked positions, the rim portions of said tumbler wheels having peripheral gates therein to receive therein confronting portions of a fence on said fence lever when the tumbler wheels are properly aligned following dialing of the proper lock opening combination, said rear wall of the lock case having an opening therein for insertion of a combination change key into the lock case and rotation thereof at as position located radially outwardly of the tumbler wheels adjacent the outer peripheries thereof, means supporting said tumbler post within the tumbler wheel hub portions for nonrotatable axial movement between first and second positions and having shoulder means forwardly and rearwardly abutting the wheel hub portions of the tumbler wheel stack for movement of the hub portions axially relative to said outer rim portions between coupled and decoupled relation therewith, rim restraint means restraining said outer rim portions against axial movement, and tumbler post positioning means within the lock case activated by rotation of the change key within the lock case between coupled and decoupled positions for axially moving the tumbler post and said tumbler wheel hub portions to shift the tumbler wheel hub portions to decoupled relation with the tumbler wheel rim portions for combination change by rotation of the hub portions to new combination positions relative to their rim portions responsive to rotation of the dial and driving cam to a new changed lock opening combination, and said tumbler post positioning means being operative to return the tumbler post and the tumbler wheel hub portions axially to positions again intercoupling the tumbler wheel hub portions and their respective rim portions responsive to rotation of the change key to coupled position.

2. A combination lock as defined in claim 1, including rim portion holding means associated with said tumbler post position-ing means moveable concurrently with movement of the latter re-sponsive to rotation of the change key to decouple and couple positions to respectively engage and hold the tumbler wheel rim portions against rotation while the tumbler wheel hub portions are being decoupled and intercoupled with their respective rim portions and while they are in decoupled relation.

3. A combination lock as defined in claim 2, wherein said rim portion holding means comprises a secondary change fence member moveable into inserted relation in the gates of said tumbler wheel rim portions and retractable therefrom, said secon-dary change fence being located in radially outwardly spaced relation to and adjacent the peripheries of said tumbler wheel rim portions.

4. A combination lock as defined in claim 3, wherein the lock includes means supporting said secondary change fence member for pivotal movement to insert a nose formation thereof into the gates of said tumbler wheel rim portions responsive to rotation of the change key between said couple and decouple positions and while occupying said decoupled position.

5. A combination lock as defined in claim 1 wherein said tumbler post positioning means comprises a lag screw member journaled for rotation adjacent the front wall of the lock case in coaxial relation to and extending into the tumbler post and the tumbler post having a threaded bore receiving the lag screw member in threaded relation therewith for axially movement of the tumbler post relative to the lag screw member between hub portion coupling position and the hub portion decoupling position relative to the tumbler wheel rim portions, and the tumbler post positioning means including means for rotating the lag screw member responsive to rotation of the change key between the couple and decouple positions.

6. A combination lock as defined in claim 5, wherein said lag screw member includes a lag screw portion threaded into the bore of the tumbler post and a gear portion located outwardly adjacent the proximal end of the tumbler post and said tumbler post positioning means includes a gear formation and actuator means receiving the change key for rotating a drive gear having gear teeth intercoupled with gear teeth of a gear formation for rotating the lag screw member to position the tumbler post.

7. A combination lock as defined in claim 2 wherein said tumbler post positioning means comprises a lag screw member journaled for rotation adjacent the front wall of the lock case in coaxial relation to and extending into the tumbler post and the tumbler post having a threaded bore receiving the lag screw member in threaded relation therewith for axially movement of the tumbler post relative to the lag screw member between hub portion coupling position and the hub portion decoupling position relative to the tumbler wheel rim portions, and the tumbler post positioning means including means for rotating the lag screw member responsive to rotation of the change key between the couple and decouple positions.

8. A combination lock as defined in claim 7, wherein said lag screw member includes a lag screw portion threaded into the bore of the tumbler post and a gear portion located outwardly adjacent the proximal end of the tumbler post and said tumbler post positioning means includes a gear formation and actuator means receiving the change key for rotating a drive gear having gear teeth intercoupled with gear teeth of a gear formation for rotating the lag screw member to position the tumbler post.

9. A combination lock as defined in claim 3 wherein said tumbler post positioning means comprises a lag screw member journaled for rotation adjacent the front wall of the lock case in coaxial relation to and extending into the tumbler post and the tumbler post having a threaded bore receiving the lag screw member in threaded relation therewith for axially movement of the tumbler post relative to the lag screw member between hub portion coupling position and the hub portion decoupling position relative to the tumbler wheel rim portions, and the tumbler post positioning means including means for rotating the lag screw member responsive to rotation of the change key between the couple and decouple positions.

10. A combination lock as defined in claim 9, wherein said lag screw member includes a lag screw portion threaded into the bore of the tumbler post and a gear portion located outwardly adjacent the proximal end of the tumbler post and said tumbler post positioning means includes a gear formation and actuator means receiving the change key for rotating a drive gear having gear teeth intercoupled with gear teeth of a gear formation for rotating the lag screw member to position the tumbler post.

11. A combination lock as defined in claim 4 wherein said tumbler post positioning means comprises a lag screw member journaled for rotation adjacent the front wall of the lock case in coaxial relation to and extending into the tumbler post and the tumbler post having a threaded bore receiving the lag screw member in threaded relation therewith for axially movement of the tumbler post relative to the lag screw member between hub portion coupling position and the hub portion decoupling position relative to the tumbler wheel rim portions, and the tumbler post positioning means includ-ing means for rotating the lag screw member responsive to rotation of the change key between the couple and decouple positions.

12. A combination lock as defined in claim 11, wherein said lag screw member includes a lag screw portion threaded into the bore of the tumbler post and a gear portion located outwardly adjacent the proximal end of the tumbler post and said tumbler post positioning means includes a gear formation and actuator means receiving the change key for rotating a drive gear having gear teeth intercoupled with gear teeth of a gear formation for rotating the lag screw member to position the tumbler post.

13. A combination lock as defined in claim 1, wherein the outer rim portions of each of said tumbler wheels has a center opening having a diameter corresponding substantially to the outer diameter of the center hub portion and said center opening of the rim portion and the outer perimeter of said hub portion having confronting substantially cylindrical surfaces adapted to releasably abut each other with the rim and hub portions in coplanar alignment and interrupted by tooth formations on each of the hub and rim portions to interfit with each other restraining the associated hub and rim against relative rotation when in the coplanar normal operating position the surface of the perimeter of each hub portion having a protruding ramp formation encircling the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circular recess therein receiving a spring member encircling the confronting hub portion and distorted from circular con-figuration to project portions thereof from said recess into engagement with the confronting perimeter surface of the associated hub portion the spring member engaging and being disposed adjacent one inclined surface of the ramp formation when the hub and rim portions are in normal operating coplanar interlocked position and being distorted by the ramp formation upon movement of the associated hub portion to combination change position displaced from the plane of the associated rim portion to engage an opposite inclined portion of the ramp formation and resiliently restrain the associated hub and rim portions in the combination change position.

14. A combination lock as defined in claim 2 wherein the outer rim portions of each of said tumbler wheels has a center opening having a diameter corresponding substantially to the outer diameter of the center hub portion and said center opening of the rim portion and the outer perimeter of said hub portion having confronting substantially cylindrical surfaces adapted to releasably abut each other with the rim and hub portions in coplanar alignment and interrupted by tooth formations on each of the hub and rim portions to interfit with each other restraining the associated hub and rim against relative rotation when in the coplanar normal operating position the surface of the perimeter of each hub portion having a protruding formation encircling the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circular recess therein receiving a spring member encircling the confronting hub portion and distorted from circular con-figuration to project portions thereof from said recess into engagement with the confronting perimeter surface of the associated hub portion, the spring member engaging and being disposed adjacent one inclined surface of the ramp formation when the hub and rim portions are in normal operating, coplanar interlocked position and being distorted by the ramp formation upon movement of the associated hub portion to combination change position displaced from the plane of the associated rim portion to engage an opposite inclined portion of the ramp formation and resiliently restrain the associated hub and rim portions in the combination change position.

15. A combination lock as defined in claim 3, wherein the outer rim portions of each of said tumbler wheels has a center opening having a diameter corresponding substantially to the outer diameter of the center hub portion and said center opening of the rim portion and the outer perimeter of said hub portion having confronting substantially cylindrical, surfaces adapted to releasably abut each other with the rim and hub portions in coplanar alignment and interrupted by tooth formations on each of the hub and rim portions to interfit with each other restraining the associated hub and rim against relative rotation when in the coplanar normal, operating position, the surface of the perimeter of each hub portion having a protruding ramp formation encircling the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circular recess therein receiving a spring member encircling the confronting hub portion and distorted from circular con-figuration to project portions thereof from said recess and into engagement with the confronting perimeter surface of the associated hub portion, the spring member engaging and being disposed adjacent one inclined surface of the ramp formation when the hub and rim portions are in normal operating, coplanar interlocked position and being distorted by the ramp formation upon movement of the associated hub portion to combination change position displaced from the plan of the associated rim portion to engage an opposite inclined portion of the ramp formation and resiliently restrain the associated hub and rim portions in the combination change position.

16. A combination lock as defined in claim 4, wherein the outer rim portions of each of said tumbler wheels has a center opening having a diameter corresponding substantially to the outer diameter of the center hub portion and said center opening of the rim portion and the outer perimeter of said hub portion having confronting substantially cylindrical surfaces adapted to releasably abut each other with the rim and hub portions in coplanar alignment and interrupted by tooth formations on each of the hub and rim portions to interfit with each other restraining the associated hub and rim against relative rotation when in the coplanar normal operating position, the surface of the perimeter of each hub portion having a protruding ramp formation encircling the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circular recess therein receiving a spring member encircling the confronting hub portion and distorted from circular con-figuration to project portions thereof from said recess into engagement with the confronting perimeter surface of the associated hub portion, the spring member engaging and being disposed adjacent one inclined surface of the ramp formation when the hub and rim portions are in normal operating, coplanar interlocked position and being distorted by the ramp formation upon movement of the associated hub portion to combination change position displaced from the plane of the associated rim portion to engage an opposite inclined portion of the ramp formation and resiliently restrain the associated hub and rim portions in the combination change position.

17. A combination lock as defined in claim 5, wherein the outer rim portions of each of said tumbler wheels has a center opening having a diameter corresponding substantially to the outer diameter of the center hub portion and said center opening of the rim portion and the outer perimeter of said hub portion having confronting substantially cylindrical.

surfaces adapted to releasably abut each other with the rim and hub portions in coplanar alignment and interrupted by tooth formations on each of the hub and rim portions to interfit with each other restraining the associated hub and rim against relative rotation when in the coplanar normal, operating position, the surface of the perimeter of each hub portion having a protruding ramp formation encircling the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circular recess therein receiving a spring member encircling the confronting hub portion and distorted from circular con-figuration to project portions thereof from said recess into engagement with the confronting perimeter surface of the associated hub portion, the spring member engaging and being disposed adjacent one inclined surface of the ramp formation when the hub and rim portions are in normal, operating, coplanar interlocked position and being distorted by the ramp formation upon movement of the associated hub portion to combination change position displaced from the plan of the associated rim portion to engage an opposite inclined portion of the ramp formation and resiliently restrain the associated hub and rim portions in the combination change position.

18. A combination lock as defined in claim 6, wherein the outer rim portions of each of said tumbler wheels has a center opening having a diameter corresponding substantially to the outer diameter of the center hub portion and said center opening of the rim portion and the outer perimeter of said hub portion having confronting substantially cylindrical, surfaces adapted to releasably abut each other with the rim and hub portions in coplanar alignment and interrupted by tooth formations on each of the hub and rim portions to interfit with each other restraining the associated hub and rim against relative rotation when in the coplanar normal operating position, the surface of the perimeter of each hub portion having a protruding ramp formation encircling the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circular recess therein receiving a spring member encircling the confronting hub portion and distorted from circular con-figuration to project portions thereof from said recess into engagement with the confronting perimeter surface of the associated hub portion, the spring member engaging and being disposed adjacent one inclined surface of the ramp formation when the hub and rim portions are in normal operating, coplanar interlocked position and being distorted by the ramp formation upon movement of the associated hub portion to combination change position displaced from the plan of the associated rim portion to engage an opposite inclined portion of the ramp formation and resiliently restrain the associated hub and rim portions in the combination change position.

19. A combination lock as defined in claim 1, wherein said drive cam includes three equally circumferentially spaced drive pin formations projecting forwardly therefrom toward the nearest tumbler wheel and located each on dif-ferent respective radii, each tumbler wheel having an annular fly member disposed against the rearwardly facing surface of its hub portion each having three lug formations thereon circumferentially spaced and radially disposed in correspond-ing with the three drive pin formations of the drive cam to be engaged thereby during rotation of the drive cam, and lost motion interengageable shoulder formations on the fly members and associated tumbler wheel hub portions for engagement and rotation of the disassociated hub portion with rotation of the fly after limited predetermined lost motion relative circumferentially movement thereof, and the surfaces of the hub portions opposite the first mentioned surfaces adjacent to the associated fly members having three drive pin forma-tions projecting toward the next foreward hub portion and located in correspondence with the drive pin formations on the driving cam.

20. A combination lock as defined in claim 2, wherein said drive cam includes three equally circumferentially spaced drive pin formations projecting forwardly therefrom toward the nearest tumbler wheel and located each on dif-ferent respective radii, each tumbler wheel having an annular fly member disposed against the rearwardly facing surface of its hub portion each having three lug formations thereon circumferentially spaced and radially disposed in correspond-ing with the three drive pin formations of the drive cam to be engaged thereby during rotation of the drive cam, and lost motion interengageable shoulder formations on the fly members and associated tumbler wheel hub portions for engagement and rotation of the disassociated hub portion with rotation of the fly after limited predetermined lost motion relative circumferentially movement thereof, and the surfaces of the hub portions opposite the first mentioned surfaces adjacent to the associated fly members having three drive pin forma-tions projecting toward the next foreward hub portion and located in correspondence with the drive pin formations on the driving cam.

21. A combination lock as defined in claim 7, wherein said drive cam includes three equally circumferentially spaced drive pin formations projecting forwardly therefrom toward the nearest tumbler wheel and located each on dif-ferent respective radii, each tumbler wheel having an annular fly member disposed against the rearwardly facing surface of its hub portion each having three lug formations thereon circumferentially spaced and radially disposed in correspond-ing with the three drive pin formations of the drive cam to be engaged thereby during rotation of the drive cam, and lost motion interengageable shoulder formations on the fly members and associated tumbler wheel hub portions for engagement and rotation of the disassociated hub portion with rotation of the fly after limited predetermined lost motion relative circumferentially movement thereof, and the surfaces of the hub portions opposite the first mentioned surfaces adjacent to the associated fly members having three drive pin forma-tions projecting toward the next foreward hub portion and located in correspondence with the drive pin formations on the driving cam.

22. A combination lock as defined in claim 5, wherein said drive cam includes three equally circumferentially spaced drive pin formations projecting forwardly therefrom toward the nearest tumbler wheel and located each on dif-ferent respective radii each tumbler wheel having an annular fly member disposed against the rearwardly facing surface of its hub portion each having three lug formations thereon circumferentially spaced and radially disposed in correspond-ing with the three drive pin formations of the drive cam to be engaged thereby during rotation of the drive cam, and lost motion interengageable shoulder formations on the fly members and associated tumbler wheel hub portions for engagement and rotation of the disassociated hub portion with rotation of the fly after limited predetermined lost motion relative circumferentially movement thereof, and the surfaces of the hub portions opposite the first mentioned surfaces adjacent to the associated fly members having three drive pin forma-tions projecting toward the next foreward hub portion and located in correspondence with the drive pin formations on the driving cam.

23. A combination lock as defined in claim 11, wherein said drive cam includes three equally circumferentially spaced drive pin formations projecting forwardly therefrom toward the nearest tumbler wheel and located each on dif-ferent respective radii, each tumbler wheel having an annular fly member disposed against the rearwardly facing surface of its hub portion each having three lug formations thereon circumferentially spaced and radially disposed in correspond-ing with the three drive pin formations of the drive cam to be engaged thereby during rotation of the drive cam, and lost motion interengageable shoulder formations on the fly members and associated tumbler wheel hub portions for engagement and rotation of the disassociated hub portion with rotation of the fly after limited predetermined lost motion relative circumferentially movement thereof, and the surfaces of the hub portions opposite the first mentioned surfaces adjacent to the associated fly members having three drive pin forma-tions projecting toward the next foreward hub portion and located in correspondence with the drive pin formations on the driving cam.

24. Tumbler wheel for a plural tumbler wheel combina-tion lock capable of manipulation to change the lock combina-tion, comprising annular outer rim portion and an inner annular hub portion, the outer rim portion of each tumbler wheel.

having a center opening having a diameter corresponding substantially to the outer diameter of the center hub portion, said center opening of the rim portion and the outer perimeter of said hub portion having confronting substantially cylindrical surfaces adapted to releasably abut each other with the rim and hub portions in coplanar alignment and interrupted by tooth formations on each of the hub and rim portions to interfit with each other restraining the associated hub and rim against relative rotation when in the coplanar normal operating position, the surface of the perimeter of each hub portion having a protruding ramp formation formed with a pair of inclined ramp surfaces converging to a crest, the ramp formation encircling the hub portion and the confronting portions of the center opening surface of the associated rim portion having a circular recess therein receiving a spring member encircling the confronting hub portion and distorted from circular configuration to project portions thereof from said recess into engagement with the confronting perimeter surface of the associated hub portion, the spring member engaging and being disposed adjacent one inclined surface of the protruding ramp formation when the hub and rim portions are in normal operating, coplanar interlocked position and being distorted by the ramp formation upon movement of the associated hub portion to combination change position displaced from the plane of the associated rim portion to engage an opposite inclined portion of the ramp formation and resiliently restrain the associated hub and rim portions in the combination change position to provide snap action relative movement of the hub portion to fully projected change position or to fully retracted coplanar interlocked position upon passage of the spring member over said crest.