US3518856A - Combination lock with cam follower positioned,cumulatively arrested tumbler elements - Google Patents

Description

July 7, 1970 A. J. POTZICK 3,518,856

COMBINATION LOCK WITH CAM FOLLOWER POSITIONED, CUMULATIVELY ARRESTED TUMBLER ELEMENTS Filed March 22, 1968 7 Sheets-Sheet 1 July 7, 1970 A. J. POTZiCK 3,518,856

COMBINATION LOCK WITH CAM FOLLOWER POSITIONED, CUMULATIVELY ARRESTED TUMBLER ELEMENTS Filed March 22, 1968 7 Sheets-Sheet 2 SLIDER HOLDING PIN \ RATCHET fla FLAPPER HOLDING STE PPING PAWL CAM

FOLLOWER W .2 WM zi gj A. J. POTZICK 3,518,856

ARRESTED TUMBLER ELEMENTS 7 Sheets-Sheet 5 m \Q MW MN July 7, 1970 COMBINATION LOCK WITH CAM FOLLOWER POSITIONED, CUMULATIVELY Filed March 22, 1968 July 7, 1970 A. J. PO'TZICK 3,513,856

COMBINATION LOCK WITH CAM FOLLOWER POSITIONED, CUMULATIVELY ARRESTED TUMBLER ELEMENTS Filed March 22, 1968 7 She ets-Shee c 4 WWW f A. J. POTZICK FOL n TUMBLER July 7, 1970 3,518,856 COMBINATION LOCK WITH CAM LOWER POSITIONED, CUMULATIVELY ARRESTE ELEMENTS 7 Sheets-Sheet 5 Filed March 22, 1968 July 7, 1970 A. J. POTZICK 3,

COMBINATION LOCK WITH CAM FOLLOWER POSITIONED, CUMULATIVELY ARRESTED TUMBLER ELEMENTS 7 Sheets-Sheet 6 Filed March 22, 1968 QMN m'm MAN July 7, 1970 J, poTz cK 3,518,856

COMBINATION LOCK WITH CAM FOLLOWER POSITIONED, CUMULATIVELY ARRESTED TUMBLER ELEMENTS Filed March 22, 1968 7 Sheets-Sheet United States Patent US. Cl. 70-499 40 Claims ABSTRACT OF THE DISCLOSURE In this combination lock, the dial turns a rotatable cam the movement of which is followed by a set of cam followers. The motions of the respective cam followers are in turn followed by tumbler elements. The elements can be arrested and held against further movement by holding means which is engageable with the respective elements in accumulating sequence. Fence members are interfittable with the respective tumbler elements if the elements have been arrested by the holding means in predetermined positions of alignment with the respective fence members. The members are coupled to a lever which is connectable to a bolt thrower to withdraw the bolt, and they are moved toward the elements when the lever is moved. The elements and members must be interfitted before the lever can contact the bolt thrower. Combination changing structure is also provided, which selectively permits changing the relative position of the members when they are interfitted with the elements.

This application is related to my copending application Ser. No. 645,849, filed May 29, 1967, titled Combination Lock With Cam Operated Tumblers and Sequentially Engageable Tumbler Stops, now Pat. No. 3,436,941, dated Apr. 8, 1969.

This invention relates to a combination lock which embodies new principles of operation.

Combination locks are responsive to a pre-established combination of numbers or letters which are set into the lock in sequence by operating a dial. For many years combination locks have been based on mechanisms which require that the dial be operated in a precise program or pattern of turning movements to set the combination into the lock. Commonly the program has required turning the dial a specified number of turns in a certain direction, say four turns to the right, before stopping at the first number or letter of the combination, then a series of turns one less in number in the opposite direction, e.g. three turns to the left, to the next number of the combination, followed by a decreasing sequence of turns in opposite directions to set the other numbers into the lock. As a practical matter, the operation of such locks is undesirably complex because of the need to remember not only the combination but also the dialing program and to execute it properly, including both the number and direction of turns required before stopping at each number of the combination. Because of this complexity, locks with combinations of more than four numbers or letters are rarely used, and such locks are relatively slow to use and require careful attention in operation.

In contrast, the combination lock of this invention obviates the precise programs of dial turning previously required. The new lock can be operated by turning the dial in either direction directly to the numbers or letters of the combination, and it does not require opposite rotations of the dial between successive numbers of the combination. Moreover, it does not require any prede- 3,518,856 Patented July 7, 1970 termined number of turns, or indeed, any turns, of the dial between succeeding numbers of the combination. When the dial of the new lock has been turned to a given number, that number is set into the lock by axial movement of a dial shaft, for example by pushing the dial inwardly a short distance. Hence the new lock operates with much greater simplicity and rapidity than combination locks of the past, because it requires no complex dial turning program. It thus makes practicable the use of combinations consisting of a larger set of numbers than previously. For example, a combination of seven numbers may be used to provide greater resistance to surreptitious attack.

Prior combination locks have also tended to have a certain amount of play, or lack of sensitivity, which renders them responsive to imprecise dial settings; that is, they can be operated by dialing numbers merely adjacent to the proper numbers of the combination. Thus a previous lock set to operate at the combination 2l-73-49 would usually operate if the dial were set at 20-74-50, thus significantly reducing the number of true combinations from the number of theoretical combinations.

In contrast, the new lock of this invention requires precise dial setting. It will not open if set at numbers which are merely adjacent the proper numbers, and it will not operate when the dial is positioned between integers. Each of the theoretical combinations is a true combination.

Another difiiculty with prior combination locks has been that they have required parts made of plastic of low radiographic density to reduce susceptibility to surreptitious analysis by X-ray. However, the use of plastic tumblers and other parts, while impeding radiographic analysis, does not provide the rigidity or stability afforded by metal parts.

In contrast, the lock of this invention affords generally equal or superior resistance to radiographic analysis, yet its structure is such that it can be made entirely out of metal, with its superior qualities of rigidity and stability.

In the conventional rotating tumbler combination locks of past, the tumblers are turned through lost motion couplings. A given tumbler moves only when the lost motion is taken up.

In contrast, in the new combination lock, movable elements which might be likened to tumblers are positioned without lost motion, by cam followers engaged with a rotatable cam.

Conventional tumbler operated combination locks are opened by setting the tumblers in positions of alignment to interfit with a fence or bar projecting from the lever which withdraws the bolt. Conventionally the tumblers are positioned to receive the fence when the tumbler gates are oriented in a straight line opposite the fence.

In contrast, in the lock of this invention what might be likened to a fence is comprised by a set of fence members which can be staggered with respect to one another. The alignment positions of the tumbler elements with the fence members with which they interfit is not limited to a straight line orientation.

In conventional key changeable tumbler operated locks, the combination is changed by changing the position of the tumbler gate with respect to the fly or drive means through which dial motion is imparted to the tumbler. In contrast, in the present lock the combination may be changed not by changing the tumbler elements, but by changing the positions of the fence members with which the tumbler elements are interfitted in positions of alignment.

Moreover, the lock of this invention permits building in other variants from lock to lock, besides the combination itself. The shape of the cam can readily be varied from lock to lock; the position and shape of that portion of the interfitting means which is on the tumbler element can differ from tumbler to tumbler, and from lock to lock, and the position and shape of that portion of the interfitting means which is on the fence member can also differ.

Briefly described, in the present lock, the dial arbor rotates a cam the movement of which is followed by a set of cam followers. The cam followers do not themselves act as tumblers, but they transmit motion of the cam to movable tumbler elements. The latter elements follow the motions of the respective cam followers, but are arrestable by holding means so that when arrested, the elements no longer follow the movements of the cam followers. The tumbler holding means is advanced in increments, as by ratchet stepping means. Interfittable means are presented in part on the tumbler elements and in part on fence members associated with the respective elements. These interfittable means can be interfitted only if the tumbler elements have been arrested by the holding means in predetermined positions of alignment with the respective fence members.

The fence members are moved as a set toward and away from the tumbler elements by a coupling to a lever which is connectable to a bolt thrower to withdraw the bolt. Movement of the lever toward bolt withdrawing position is blocked by disoriented tumbler elements, and connection to withdraw the bolt can only be made if all the tumbler elements are interfitted with the respective fence members.

The combination of the lock is dependent upon the positions of the gates or other interfitting means on the respective fence members. Optional structure is provided whereby the positions of the members with respect to one another can quickly be changed thereby to change the combination. This structure includes means for clamping the members in fixed positions with respect to another, which means can be released when the members have been interfitted with the respective tumbler elements and the bolt has been withdrawn.

In some conventional tumbler operated locks, it is possible to tap the fence by means of rotating the gate in the bolt thrower under the nose of the lever. The camming engagement of the bolt thrower with the lever nose gently lifts and lowers the fence off the tumbler peripheries and it is sometimes possible to obtain an indication of tumbler gate orientation in this manner.

Preferred structure in the present lock eliminates the possibility of such tapping. The lever and the fence members are held away from the tumbler elements until all of the elements have been arrested by the holding means. As the last tumbler element is set, the lever is abruptly released and it drops uncontrollably under the influence of a biasing spring toward the bolt thrower. If the proper combination has been dialed, so that all elements align with the fence members, then the members can drop to the fullest extent. Only when that occurs will the nose of the lever contact the periphery of the bolt thrower. When the fence members drop to the fullest extent, the nose of the lever can enter a gate in the bolt thrower, and thereby be connected to withdraw the bolt. The bolt thrower rotates at all times with the cam shaft and the lock arbor, and need not be disconnected from the cam to withdraw the bolt.

The details and features of the invention can best be further described by reference to the drawings in which:

FIG. 1 is a perspective view of the preferred embodiment for this invention, showing the lock mounted to a safe door, partly broken away, with the lock cover removed and the bolt in extended position;

FIG. 2 is a simplified diagrammatic perspective illustrating major operating components of the lock;

FIG. 3 is a horizontal section taken along the line 33 in FIG. 1, with the lock cover in place;

FIG. 4 is a vertical section taken along line 44 of FIG. 3, with the lock cover removed;

FIG. 5 is a vertical section taken along line 5-5 of FIG. 3;

FIG. 6 is a vertical section taken along line 66 of FIG. 4;

FIG. 7 is a vertical section similar to FIG. 6 but shows the tumbler holding means advanced to the position at which all of the respective tumbler elements are held against movement and the lever is lowered for bolt retraction;

FIG. 8 is a vertical section taken on line 88' of FIG. 4;

FIG. 9 is a fragmentary horizontal section showing the fence set, taken on line 99 of FIG. 4;

FIG. 10 is a fragmentary horizontal section taken on line 1t)10 of FIG. 5 showing the ratchet stepping means in starting position;

FIG. 11 is a fragmentary horizontal section similar to FIG. 3, but shows the position of the ratchet stepping means when the arbor is pushed in to set a dialed number;

FIG. 12 is a fragmentary section taken on line 1212 of FIG. 5 and illustrates the holding pawl of the stepping means;

FIG. 13 is a fragmentary section similar to FIG. 11 but illustrates the position of the stepping means when the arbor is pulled out to clear the lock; and

FIG. 14 is a sectional view similar to FIG. 12 but illustrates the position of the holding pawl when the arbor has been pulled out to clear the lock.

GENERAL DESCRIPTION A general understanding of the components and operation of a preferred form of this combination lock can be gained by reference to the structure diagrammatically shown in FIG. 2.

Rotating the lock dial (not shown in FIG. 2), turns a driver which is connected to rotate cam means in the form of a disk-like cam. One end of a pivoted cam follower is spring urged into contact with the shaped periphery of the cam, and the cam follower turns and follows the cam surface as the driver is rotated. The other end of the cam follower bears upon and cams a movable tumbler element or slider in sliding movement. The slider is spring urged against the cam follower and is positioned in accordance with the position of the driver. The lock includes a number of sets of cams, cam followers and sliders, only one set of which is shown in FIG. 2 for purposes of explanation, the other sets being similar. Thus, as the lock dial is dialed to a certain number, the sliders are slid to various positions.

At the start of running the combination, rotation of the dial operates all of the cam followers and sliders, but as the numbers are dialed and set, the respective sliders are arrested in sequence by tumbler holding means or a slider holding pin which engages one of a series of holes in each slider. This slider holding pin is mounted to and moves with a ratchet. The ratchet is moved in steps to engage the sliders one by one in accumulating sequence, by setting the number by pushing axially on the lock dial after each combination number is dialed. Pushing in on the dial moves a flapper or lever to which a stepping pawl is attached, which in turn pushes the ratchet forward one notch. When the ratchet has been so advanced, a holding pawl prevents its return while the flapper is returned to its starting position, during which the stepping pawl drops back to its starting position, ready to advance the ratchet again upon the next push of the dial. This sequence causes the slider holding pin to engage and arrest one slider, and is repeated for each slider as it is set in sequence.

A set of fence members are interfittable with the tumbler elements or sliders, each slider having a tooth which must be aligned with a gate on the corresponding fence member before the bolt can be withdrawn; the slider teeth can be interfitted with the respective gates only if all of the teeth are properly aligned with the respective gates. The fence members are mounted for movement toward and away from the slider teeth, and for that purpose respond through a sliding coupling to movement of a lever which is in turn connected to the bolt. The lever has a nose at one end which is engageable in a notch on a bolt throwing cam when the lever nose is properly oriented with respect to the notch, so that the bolt can be withdrawn.

During running of the combination the lever nose is prevented from contacting the bolt thrower notch by a leg which rests on the ratchet. When the last slider has been engaged by the pin (which corresponds to setting of the last number), the lever leg is released or dropped off the ratchet, and the lever drops toward the bolt throwing cam. The fence members respond to movement of the lever by moving toward the slider teeth. If the sliders are correctly positioned, their teeth will interfit with the respective fence member gates so that the lever nose can drop into engagement with the bolt throwing cam notch. If the sliders are not properly oriented, then one or more of the disaligned slider teeth will block and prevent such interconnection of the lever to the bolt throwing cam. When the lever is engaged in the bolt throwing cam, the bolt can be withdrawn by further rotation of the driver. The lock is cleared by pulling out on the dial which releases the pawls from the ratchet, and a spring moves the slider holding pin out of engagement with the sliders so that all the sliders again bear on the cam followers and are scrambled by the cams.

SPECIFIC DESCRIPTION The combination lock illustrated for purposes of explanation is seen in FIG. 1 as mounted adjacent the edge of a safe door 20 with the lock bolt 21 in locked or extended position. The lock is manually operated through the dial means designated generally by 22 in FIG. 1, by turning a dial or knob 23 having number graduations 24 thereon alignable with an index mark (not shown) on a stationary surrounding frame or housing 25. As will be described hereinafter, dial 23 can both be rotated about its axis, and at certain positions can be pushed inwardly (that is, toward door 20) over a short limited distance. At one position dial 23 can be pulled outwardly a short distance. The periphery of dial 23 is marked with a series of numbers, preferably the integers 0-9, but it will of course be appreciated that it can be marked with more or fewer numbers or letter designations. The lock is further explained hereinafter with specific reference to a lock dial having the integers 0-9 on it.

The lock itself is mounted to the inside of the door 20, and is contained within a housing or casing having a base or frame 28, mounted to safe door 20 by machine screws 29 which pass through bosses in the four corners of the base 28. A lock cover 30 fits over and is secured to base 28 through fixed internal components thereof by machine screws 31 (see FIG. 3).

As best seen in FIG. 3, an operating shaft or arbor 33, to which dial 23 is connected, extends into the lock casing through an opening in the bottom 34 of base 28 (the lock is frequently referred to herein as if viewed with the bottom 34 of the base resting upon a horizontal surface, so that down refers to the direction toward base 34, while up refers to the direction toward surface 35 of cover 30).

Arbor 33 is threaded adjacent its upper end, and a generally cylindrical driver 36 is threaded onto it and keyed to the arbor by a key 37. An opening 38 in top surface 35 may be provided so that key 37 can be inserted with the cover in place. Driver 36 is thus fixed to arbor 33 for both rotation and axial movement therewith.

Just above the case bottom 34, driver 36 has an outer flange 39 having a groove 40 in its rim. A plurality of notches or cross-slots 44 are spaced equally around flange 39. The notches 44 correspond in angular position and number to the integers on dial 23. A pin or stud 45 (see FIG. 3), which may be formed on a corner boss of base 28, overhangs the rim of driver flange 39, and this stud 45 is shaped so as to prevent upward movement of arbor 33 and driver 36 (i.e., movement imparted to the arbor by pushing dial 23 toward the safe door) by abutting driving flange 39 unless the arbor is so oriented that one of the rim notches 44 is aligned to receive stud 45 (see FIG. 4). Since the positions of the notches 44 correspond to integer positions on the dial, stud 45 thus prevents the shaft 33 from being pushed inwardly unless the dial is aligned at a whole number. In this connection, it is noted that a small lead or round may be provided on either stud 45 or the notches 44, to cam the driver into proper aligned position if it is only slightly disali-gned when the dial is pushed in. These means insure that the dial can be pushed in only at whole number positions and not at substantially misaligned fractional or intervening orientations.

"Pull-out movement of dial 23 that is, movement which tends to move shaft 33 downwardly as seen in FIG. 3, is limited by pin or stud 46 on the base 28. This stud 46 abuts the driver unless a single recess or opening 47 in the driver is aligned with the stud 46. The recess 47 is preferably so located that the driver can be pulled out only when the dial is set at zero. A small taper can be provided to align the dial if it is set just slightly out of exact position. By reason of their effects in limiting axial movement of shaft 33, the studs 45 and 46 are sometimes referred to hereinafter as the push-in and pull-out pins, respectively. Interengagement of the driver flange 39 with the push-in pin 45 is shown in FIG. 11, and the interengagement of the driver flange with the pull-out pin 46 is shown in FIG. 13.

The driver is urged to a centered or neutral axial position in which it does not engage either the push-in or pull-out pins 45 or 46, by biasing means in the form of a push-plate or flapper designated generally by 50 (see FIGS. 3 and 5). The flapper 50 is pivoted at one side to base 28 for rotation about an axle or shaft 51 which is transverse to the axis of arbor 33, and has a rounded outer end 52 which is engaged within driver groove 40 and which slides therein as the driver is rotated. Opposed springs 53 and 54 engage opposite sides of flapper 50 and bias it toward its centered or neutral position.

The shank of driver 36 is provided with angularly spaced longitudinal grooves 56 in each of which a ball key 57 rides. The ball keys provide a sliding universal joint whereby the driver is connected to rotate a hollow cylindrical earn shaft 59 which loosely encircles the upper end of the driver 36 (see FIGS. 3 and 4). The balls 57 reside in recesses or openings 60 in cam shaft 59. It can be seen that this interconnection permits the driver 36 to be shifted axially while at all times remaining rotationally interconnected to the cam shaft. This method of interconnection has the advantage of permitting some cooking of arbor 33 with respect to the cam shaft, without causing binding thereof. Cam shaft 59 is journalled at its upper and lower ends for rotation in a midplate and top plate designated by 64 and 65 respectively (see FIG. 3), both of which are secured to the lock base 28 by means to be described.

Midplate 64 is seated on bosses formed on base 28 and is located thereon by a stud or pin 68 and fastened to the base by screws 69 (FIGS. 3 and 4). A bearing 70 may be press-fitted around the shaft opening in midplate 64 to journal the cam shaft 59. Beneath midplate 64 a bolt thrower or bolt-throwing cam 72 having a peripheral notch 73 is secured to cam shaft 59 for rotation therewith. At the upper end of the cam shaft, above top plate 65, a spring retainer 75 is snapped into a groove in the cam shaft. Thus the bolt throwing cam 72 and spring retainer 75 prevent axial movement of the cam shaft.

The top plate is spaced from and mounted to the midplate 64 by spacer sleeves 76 on screws 77 (see FIGS.

1 and 4). The lock cover is secured by the machine screws 31 to the top plate 65 (see FIG. 3).

A set of cam disks 79, seven in number in the embodiment shown, are mounted on cam shaft 59 for rotation therewith. One suitable outline form for the cam disks is shown in FIG. 4. It is convenient for manufacturing purposes (although not necessary) that all the cams be similar in outline; to scramble them, the cams are differently oriented on the cam shaft. To that end the cams are splined to the cam shaft through points 80 on each cam which interfit with a series of corresponding grooves 81 formed on the cam shaft (see FIG. 4). The various possible angular positions of the cams correspond to whole number settings of the dial 23. It can be seen that cam arrangement can readily be varied from lock to lock simply by changing the cam orientations on the cam shaft.

For each cam 79 there is provided a cooperating cam follower 83, a tumbler element or slider 84, and a fence member 85 (see FIGS. 2 and 4), together with associated biasing springs to be described. Thus, in the embodiment shown there are seven such sets, each including a cam, cam follower, slider and fence member. The sliders form a pack or deck, as do the fence members.

As seen in FIGS. 3 and 4, the cam follower 83 may be levers, and are pivotally mounted between the top plate and midplate on a post 87. At one end, each cam follower 8-3 is provided with a rounded tip 88 which is urged by a biasing spring 89 toward engagement with the periphery of the respective cam 79. At its other end each cam follower 83 has a slider-engaging camming surface 90.

As seen in FIG. 4, each slider 84 may be a flat, generally rectangular, slotted element supported for sliding movement on a pair of posts 94. Slider biasing springs urge the respective sliders 84 into engagement with the tips 90 of the cam followers, and the sliders are thus cammed in sliding movement on posts 94 as the cam followers 83 follow movement of the cams 79 when the dial 23 is rotated. Each slider 84 has a fence member interfitting portion such as a tooth 96 which, when properly aligned, will engage or interfit with a cooperating interfitting portion such as a gate 97 on the respective fence member 85 (see FIGS. 2 and 4). Each slider 84 is also provided with a series of openings or holes 98 which are aligned with holding means in the form of a shaft or pin 100 at whole number dial positions. The respective sets of cam followers, sliders and associated springs 89 and 95 are separated from one another by interleaved spacers 101 (see FIG. 4) which are positioned by the posts 76 extending between the midand top plates. The springs 89 and 95 are held in place by spring retainers 102, the retainers being sandwiched between the spacerplates 101 and mounted on the posts 76. The spacers 101 prevent each cam follower from engaging any cam or slider other than that with which it is associated.

The cam follower biasing spring 89 is stronger than and overrides the slider biasing spring 95 so that the cam follower 83 rides on the periphery of the cam 79. The slider 84 follows the movement of the cam follower 83 so long as the slider is not held in fixed positin by engagement of pin 100 in any of the holes 98 therein. When any slider is so held by pin 100, the respective cam follower will ride on the came periphery over the radial extent permitted within the limit imposed by the fixed slider 84.

The holding pin 100, by which the respective sliders can be held in positions corresponding to whole number dial settings, is mounted to and projects toward the lock top surface 35 from an L-shaped bracket 105 (see FIGS. 5 and 6). Bracket 105 is secured as by brazing onto a flat formed on one surface of a ratchet member designated by 106. Ratchet member 106 is generally sleevelike, and is provided with a series of steps or V-shaped circumferential grooves 107 on its outside surface, for

engagement by pawls. The ratchet 106 is mounted for axial sliding movement along a shaft 109 having an axis parallel to the axis of arbor 33. Holding pin 100 is mounted to its bracket 105 parallel to shaft 109. Shaft 109 is received at one end in a recess of a boss 108 formed in the lock bottom 34 and is received at the other end in the lock top plate 65 (see FIGS. 3 and 6). A coil spring 110 around shaft 109 bears on the ratchet and urges it toward an initial, cleared, or starting position shown in FIG. 3, at which the ratchet abuts the boss 108 on the look bottom 34.

From FIG. 6 it can be seen that as the ratchet is advanced in the direction toward the lock top 35, the pin 100 is passed in sequence through the sliders 84, extending through the holes 98 therein. As will be seen, the holes 98 are positioned in the sliders to align with the pin as the pin is advanced; the positions of the holes are those in line with the pin at the whole number settings of dial only at which the dial can be pushed in. The ratchet 106 is sequentially advanced by push-in movement of dial 23 through a stepping or advancing pawl 112 shown in FIG. 3, and is held in each position of advancement by a holding pawl 113, shown in FIG. 6.

As best shown in FIGS. 2, 3, and 5, the stepping pawl 112 is pivotally mounted on flapper 50 on a shaft between two cars or legs 115 and 116, and has a tip which is shaped to interfit in the ratchet notches 107, toward which position it is urged by a biasing spring 119. An outer end portion of the stepping pawl extends through an opening formed in the flapper 50, and is positioned for engagement by a stepping pawl release cam 121 on the case bottom 34. Such release is illustrated in FIG. 13, wherein it can be seen that when arbor 33 is pulled out, it moves the flapper 50 toward bottom 34- so that cam 121 engages and cams stepping pawl 112 out of engagement with the notches 107 on ratchet 106, so that the stepping pawl then exerts no force on the ratchet.

When arbor 33 is pushed inwardly flapper 50 is moved toward the top 35 (see FIG. 11), and the stepping pawl 112, engaged in one of the notches 107, exerts an axial force on ratchet 106 which moves the ratchet upwardly toward the lock top 35. It is thus the function of the stepping pawl 112 to advance the ratchet; it is the function of the holding pawl 113 to hold the ratchet in any incremental psition to which it has been advanced by the stepping pawl. As best shown in FIGS. 2, 5 and 6, the holding pawl 113 is pivotally mounted on the lock midplate 64 between two ears 124, 125 formed thereon. A holding pawl biasing spring 126 urges the tip of the pawl into engagement with a notch 107 on ratchet 106. When flapper 50 is pushed into advance the ratchet, movement of the ratchet cams the holding pawl 112 out of one notch and it drops into the next lower notch. When the flapper 50 is returned to centered psition (i.e. when the push-in force on the dial is released), the holding pawl 113 engages and holds the ratchet position while the stepping pawl 112 is cammed out of one notch 107 and drops into the next lower notch.

Holding pawl 113 has an outer end portion 127 which extends into an opening in the flapper (see FIGS. 2, 5 and 6) and is disposed to be engaged by a holding pawl release cam surface 128 on the flapper when the arbor is pulled out. This operation can be seen in FIG. 14. Pullout movement on arbor 33 swings flapper 50 toward lock bottom 34, and surface 128 cams holding pawl 113 out of engagement with ratchet 106. Since pull-out movement on the arbor also causes the stepping pawl 112 to be cammed out of engagement with ratchet 106, as explained above, the ratchet is then moved by spring 110 to the starting or home position shown in FIG. 3.

Clearance is provided in midplate 64 for movement of the respective pawls, as shown in FIGS. 6, 11 and 14. Together, the stepping and holding pawls 112 and 113 cooperate with the ratchet 106 to provide sequential advancing means for moving pin 100 in increments through the stack of sliders 84 in response to push-in movements of the arbor. The ratchet notches 107 are sized to effect an advancement of the ratchet equal to the thickness of one slider and spacer pair. Advancement of the pin through all the sliders is illustrated in FIGS. 6- and 7, FIG. 6 illustrating the position of the pin when it is engaged with the first slider only, while in FIG. 7 the positions ofthe components are shown when the pin has been advanced to hold all the sliders in place against movement responsive to the cam followers 83.

The set of fence members, each designated by 85, corresponds in number to the number of ca-rn disks, cam followers, and sliders. Each member 85 has a gate 97 with which the tooth 96 of the respective slider is interengageable. As shown in FIG. 4, the individual members 85 may be generally rectangular in form, and (when released) are slidable along a path parallel to the movement of the sliders '84, on a sleeve 132 which passes through slots 133 in the members. As can be seen from FIGS. 6 and 7, the sleeve 132 is brazed or otherwise fixed at its end closest to the case bottom 34, in a fence mounting means or block 134.

As seen in FIG. 6, the fence mounting means 134 includes an overhanging top flange 136, against which the upper edges (as seen in FIG. 6) of the separate members 85 reside. Thus, it keeps the members from cocking or turning around sleeve 132. The members are clamped against bracket 134 by a fence lock shaft 137 having a cross pin 142 that engages sleeve 132, the inner end of which is in turn secured to bracket 134. The head of shaft 137 bears upon a fence clamping leaf spring 138, which in turn presses upon a pressure plate 139. Pressure plate 139 is juxtaposed with the uppermost member 85.

As seen in FIG. 6, the lower end of fence lock shaft 137 is provided with a tip portion 141 that projects beyond mounting means 134, for engagement by a bolt lever to be described. The cross pin 142 of the shaft 137 cooperates with a series of contiguous slots in the sleeve 132 (see FIGS. 6, 7, and 9) to alternately hold the fence members in fixed position, or to release them for sliding movement relative to one another. When pin 142 is aligned in the shorter slot 143 in sleeve 132, the fence members are clamped in place; when shaft 137 is turned so that the pin 142 is released from the short slot 143 and moved into the longer slot 144 the compression of spring 138 is released and the members are free to slide to the extent permitted by their slots 133.

A boss 146 (see FIG. 6) on the lower side of mounting means 134 has a tongue 148 that projects into a slot 149 formed in midplate 64. The fence pack is supported and guided for sliding movement toward and away from the sliders by the tongue 148 in slot 149, and by ribs 147 (see FIG. 9) formed on the midplate adjacent the edges of bracket 134. The fence pack, including the individual members 85, shaft 137, mounting means 134, and associated structure, is slidable relative to the midplate, between the disengaged position shown in FIGS. 4 and 6, in which the gates 97 are disengaged from and out of contact with the teeth 96, and the engaged position shown in FIG. 7 in which the teeth 96 are each received in and interfit with the respective gates 97. Such interengagement can occur only if the sliders are in positions in which the individual teeth are aligned with the gates.

A fence biasing spring 150 bears on the projecting boss 146 of the fence mounting means 134, and urges the fence assembly toward the slider teeth 96. When the fence members are engaged with the respective slider teeth, as shown in FIG. 7, it can be seen that the slotted head of shaft 137 is accessible through an aperture 151 formed in the top surface 35 of the lock case cover 30, so that the shaft can be turned by a screwdriver.

In essence, the combination of the lock is determined by the positions of the respective gates 97. The gates are typically set in positions of disorder, so that the slider teeth must be set at different positions to align with and interfit with the respective fence gates.

Contact of the fence members with the slider teeth 96 during setting of the combination is prevented by engagement of the fence lock shaft tip portion 141 with a bolt lever designated generally at 155. This element 155 is best seen in FIG. 5, and at one end is pivotally connected as at 156 to the bolt 21. This lever has a leg 157 the end of which rests on a flat surface 163 of pin bracket 105 until the ratchet has been indexed to engage pin with all the respective sliders (see FIGS. 5 and 6). At the end opposite from pivot 156, lever 155 has a nose 158 that is shaped to interfit with the notch 73 of the bolt thrower or bolt throwing cam 72 when aligned therewith. A leaf spring 159 constantly bears on the lever 155 so that leg 157 thereof rides upon surface 163 of the pin bracket 1'95, tending to move nose 158 toward the periphery of the bolt throwing cam 72 (see FIG. 2).

Lever 155 is provided with an angulated slot 161 having a width equal to the diameter of shaft tip 141. When the bolt is extended, as shown in FIG. 5, tip 141 resides in this slot so that the fence members to which shaft 137 is connected are prevented from moving toward the sliders. The slot 161 is positioned or located so that clearance is maintained between the fence members and sliders, and between the lever nose 158 and the bolt thrower periphery, so long as leg 157 rides on surface 163. This prevents any possibility of detecting contact between the teeth 96 and the fence members.

As seen in FIG. 6, the surface 163 of pin bracket is in a plane parallel to the axis of pin 1% and shaft 109. As a result, when ratchet 166 is indexed to arrest the respective sliders 84 this surface 163 slides beneath lever leg 157 without swinging lever around its pivot 156. Thus, engagement of lever nose 158 with the periphery of the bolt throwing cam 72, and contact of the slider teeth 96 with the respective tumblers 85, does not occur during indexing of the sliders while the combination is being run. As also seen in FIG. 6, at the lower end of pin bracket 105, adjacent lock case bottom 34, there is provided an angulated or cam surface 164 leading from flat 163. When the pin is indexed to engage the last slider, lever leg 157 is dropped off the angulated surface 164 (see FIG. 7). Under the influence of spring 159, the lever thereby moves toward the bolt throwing cam, and it carries the fence pack toward the sliders. If the slider teeth are all aligned with the respective gates, lever nose 158 will under these circumstances engage the bolt throwing cam 72. If any of the sliders is disaligned, it will hold the lever nose off the periphery of cam 72.

Bolt 21 is received for sliding movement in guides or ways formed in the lock base 28 (see FIGS. 3 and 5). The pivot member 156 by which lever 155 is connected to the bolt has an enlarged head 1 67 which slides in a T-shaped slot 168 formed in midplate 64. The slot guides the bolt and prevents it from cocking as it is moved between extended and withdrawn positions.

By reference to FIGS. 3 and 8, it can be seen that the flapper pivots 51 are received or journalled in spaces defined between projecting ribs or bosses 170; and 171 formed on the lock base 28 and midplate 64 respectively. As previously explained, the flapper springs 53 and 54 are torsion springs encircling the flapper pivots 151 and they act in opposition or buck one another, thereby urging the flapper toward the neutral or centered position shown in FIG. 3.

OPERATION IN RUNNING THE COMBINATION Assuming that at the start the lock is in the position shown in FIG. 3, with the sliders and fence members in disarray, setting the combination is started by turning the dial 23 to the first number of the combination. As previously expressed, this can be done by turning the dial in either direction, that is, either clockwise or counterclockwise, directly to the number. No prescribed program of 1 1 numbers of turns, or of movements in alternating clockwise and counterclockwise directions, need be followed.

Rotation of the dia is imparted to cam shaft 59 and and cams 79 through the universal ball joint incuding the balls 57 and ball grooves 56. As the cams rotate, the cam followers 83 follow the peripheries of the cams, and correspondingy cause the respective sliders to be moved laterally on the posts 94. The springs 89 urge the cam followers toward the cams, and the springs 95 hold the sliders in engagement with the cam followers, so that the sliders are positioned according to the dial setting. When the dial is at the desired number, the number is set by pushing the dial inwardly. This can be done only at precise or whole number dial positions, and not at intermediate positions, for unless the dial is at a position at which push-in stud 45 on the frame is aligned with one of the push-in notches 44 on the driver flange 39, the stud will block push-in movement. This prevents restriction of the effective number of possible combinations, since the lock will not respond to intermediate dial settings.

Assuming, then, that the dial is at an integer setting, pushing in on shaft 33 causes the flapper 50 to be pivoted clockwise (as seen in FIG. 3) about its pivots 51. In the manner previously described, the steping pawl 112, which is engaged with the first notch 107 of ratchet 106, shoves the ratchet incrementally toward top surface 35,, and the holding pawl 113 drops into the second notch of the ratchet. Further push-in movement of flapper 50 is limited by a stop (not shown) on the dial. When the push-in force on the dial is released, the flapper is returned to its neutral position by its biasing springs 53 and 54. As this occurs the holding pawl 113 prevents the ratchet from sliding back to starting position under the influence of the ratchet spring 110, and the stepping pawl 112 drops into the second notch of the ratchet.

Advancing of the ratchet by this first push-in or indexing motion moves pin 100 an increment sufficient to cause it to engage one of the holes 98 in the first slider 84, and thereby holds that slider against further movement. Thereafter that slider remains set at the same position, and if the number to which the dial has been turned is the true first number of the combination, in that position the tooth of the first slider will be aligned opposite the gate 97 of the first fence member.

The combination setting operation continues in similar fashion until all of the numbers of the combination have been dialed and set into the lock. The holes 98 are so positioned in the sliders that when the dial is set at any whole number position a hole 98 will be in alignment with the pin 100 and the slider is arrested in such position. Further, the ratchet notches 107 are dimensioned so that each push-in on the flapper advances the holding pin 100 from one slider to the next.

When the seventh or last number of the combination is dialed and the dial is pushed in, the final advancing movement of the ratchet 106 carries camming surface 164 from beneath the lever leg 157, and the lever 155 is permitted to drop from that surface. Such lever movement is imparted to the fence pack by the inter-engagement of fence shaft tip 141 in the lever slot 161. If, as is assumed for this example, the correct combination has been set into the lock, then all of the slider teeth 96 will be correctly aligned opposite the disarrayed fence gates 97, and as the fence pack is moved toward the sliders, these will interfit, and the siders do not block the drop of the lever. Hence the lever nose 158 drops onto the periphery of the bolt throwing cam 72.

As a final step, dial 23 is turned to a predetermined or constant final position (typicaly zero position), which brings the bolt throwing cam notch 73 into alignment with the lever nose 158, and the lever nose drops into the notch, thereby connecting the lever to withdraw the bolt. Further counterclockwise rotation of arbor 33 (as seen in FIG. cams lever 155 to the left, As this occurs, it

12 an be seen that the fence shaft tip 141 slides in the lever slot 161, and the lever leg 157 moves to the left off of the ratchet surface 165. Continued arbor rotation withdraws the bolt.

The bolt is extended by opposite rotational movement of the driver. Coaction of lever nose 158 with the edge of notch 73 earns the lever out of the notch. Simultaneously, engagement of the pin 141 in slot 161 cams the fence pack away from the sliders, and lever leg 157 is lifted from surface 165. When the bolt is extended, the lower surface of the leg 157 is substantially aligned with the camming surface 164. With the bolt extended, the lock is cleared by pulling outwardy on dial 23. Such pull-out axial motion or the arbor is limited to a position, such as dial zero position, at which the pull-out stud 46 on the lock case is aligned with the pull-out opening 47 in the driver flange.

When arbor is pulled out, the flapper moves the stepping pawl 112 into engagement with the stepping pawl release cam 121, and the pawl is swung out of the ratchet notches. Similarly the camming surface 128 on the flapper disengages the holding pawl 113 from the ratchet notches. The ratchet is then free to move to its original or starting position under the bias of the spring 110. As the ratchet returns to starting position, camming surface 164 earns the driver leg 157 onto the flat 163, the fence members are disengaged from the respective teeth, and pin is backed out of engagement with all of the respective sliders. As the sliders are released, they are again moved into engagement with their respective cam followers, and their positions are again determined by the cams.

From the foregoing it can be seen that in setting the combination the sliders are moved from starting positions of unknown disarray, to positions of known disarray corresponding to the combination, and that when the lock is cleared, they are returned to positions of unknown disarray.

CHANGING THE COMBINATION The combination of the lock is dependent upon the respective positions of the fence gates 97. An important feature of the preferred lock of this invention is that the combination can readily be changed without dissassembly of the lock, and even without removal of the cover 30.

To change the combination, the previous combination must first be run in the usual manner and the bolt withdrawn. The fence members are thereby interfitted with the respective sliders. The head of the fence lock shaft 137 is now accessible through aperture 151 in lock cover 30 (see FIG. 7). By rotating shaft 137 so that the clamping force on the fence members is released, the members are freed so that they can individually be moved to new positions, for lock shaft cross pin 142 rides in the l nger slot 144 of sleeve 132, and spring 138 shifts the shaft 137 so that the tip 141 thereof is disengaged from the lever slot 161. The bolt is then extended, but the fence members are now disconnected from the lever and therefore are not lifted out of their engagement with the sliders. Next, the new combination is run in the ordinary manner, with the bolt extended. However, as the new combination is run, not only do the sliders follow the camming movement of the cam followers, but the fence members are also shifted by the sliders and follow the slider movement, so that the fence members are positioned in accordance with the cams. Stepping of the ratchet holds each slider by the engagement of pin 100 in a hole 98, as stated earlier.

When the new combination has been run, the bolt is again withdrawn, shaft 137 is turned so that the fence members are clamped in their new positions, and tip 141 is again positioned to couple the fence pack to the lever. When the bolt is thrown and the lock is cleared, the fence members are lifted out of engagement with the sliders, in their new positions.

Another feature of the present lock is that it can accept sliders and/or fence member of several different shapes, which have the teeth and gates in different positions thereon. This individualizes each lock. Another degree of individuality can also be built in by changing the positions of individual cam disks 79 on the cam shaft from lock to lock. This can readily be done in assembly of the cam disks on the cam shafts, since thecams can be placed thereon in any of the several orientations permitted by the interfitting points 80 and slots 81. This changes the relation of the dial to the fence gates, or the starting disarray, from lock to lock, and in addition to the fact that the combination itself is varied from lock to lock, this provides additional resistance against surreptitious attack.

For purposes of illustration, I have described herein a preferred example of a lock construction embodying the features of this invention. However, those skilled in the lock art will recognize that the invention is not limited to this embodiment alone, but is susceptible of variations and modifications including but not limited to use of other interfitting means on the tumbler elements or sliders, and the fence members, than the teeth and gates shown herein. For example, the positions of the teeth and gates can be reversed; or other interfitting means can be used. Further, individual cam disks need not be used, but instead an axially symmetric cam may be provided. Use of pivotally mounted cam follower engaging tumbler elements in place of the sliders shown is also envisioned.

I claim:

1. A combination lock comprising,

rotatable cam means,

a set of cam followers cammed by rotation of said cam means,

a set of movable elements biased toward engagement with the respective cam followers for movement therewith,

a set of members interfittable with the respective movable elements if the respective movable elements are in predetermined positions of alignment with respect thereto,

holding means engageable with each said movable element to arrest said element and thereby prevent said element from moving with the respective cam follower,

means for cumulatively engaging said holding means with the individual movable elements,

a bolt,

a lever connectable to withdraw said bolt,

and means responsive to movement of said lever to move said members toward the respective elements, said members having surface means thereon engaging said elements to block connection of said lever to withdraw said bolt unless said elements are arrested by said holding means in said predetermined positions of alignment with the respective members.

2. A look in accordance with claim 1 wherein said movable elements are in the form of flat plates and are arranged as a pack.

3. A lock in accordance with claim 1 wherein said movable elements are mounted for linear sliding movement relative to one another.

4. A lock in accordance with claim 1 wherein said cam followers are levers each having an area riding on said cam means and a second area spaced therefrom contacting the respective movable element to cam the latter in accordance with rotation of said cam means.

5. A lock in accordance with claim 1 wherein said cam means comprises an assembly of discrete disk-like cams engaged by the respective cam followers and rotated together.

6. A lock in accordance with claim 5 wherein said lock has a dial-operated cam shaft, and wherein said cams are keyed on said cam shaft.

7. A lock in accordance with claim 6 wherein keying means are provided at spaced angular positions on said cam shaft so that said cams can be keyed thereon in different orientations.

8. A lock in accordance with claim 1 further comprising ratchet and pawl means for moving said holding means in increments.

9. A lock in accordance with claim 1 wherein said holding means comprises a pin movable transversely to the movable elements, and a series of holes in each said element in which said pin can interfit to arrest said element.

10. A lock in accordance with claim 9 wherein the shaft of said holding means is mounted to a ratchet.

11. A look in accordance with claim 10 wherein said ratchet is moved by pawl means responsive to axial movement imparted to a shaft.

12. A lock in accordance with claim 11 wherein said ratchet is mounted for movement along a path parallel to the axis of said shaft, and said pawl means is actuated by a lever mounted to be swung by axial movement of said shaft.

13. A lock in accordance with claim 12 wherein said pawl means comprises a stepping pawl moving said ratchet in response to axial movement of said shaft, and a holding pawl holding said ratchet during return of said stepping pawl.

14. A lock in accordance with claim 11 wherein said shaft is rotatable as well as axially movable and is connected to rotate said cam means.

15. A lock in accordance with claim 1 wherein said members are arranged as a pack and are mounted for sliding movement toward said members.

16. A lock in accordance with claim 15 wherein said pack is coupled to said lever by a shaft cammed by movement of said lever.

17. A lock in accordance with claim 1 which further includes clamping means clamping said members together,

and means for releasing said clamping means when said members are interfitted with said elements.

18. A lock in accordance with claim 17 wherein said clamping means also couples said set of members to said lever.

19. A lock in accordance with claim 18 wherein said clamping means also includes structure decoupling said set of members from said lever when said clamping means is released from said members.

20. A combination lock comprising,

rotatable cam means,

an arbor for turning said cam means,

a set of cam followers cammed by turning of said cam means,

a set of movable elements biased toward engagement with the respective cam followers for movement therewith,

holding means engageable with said movable elements to prevent said elements from movnig with their respective cam followers,

ratchet and pawl means for advancing said holding means into holding engagement with the respective movable elements in accumulating sequence.

a set of members mounted for movement toward said movable elements,

interfittable means presented in part on said members and in remaining part on said elements interfitting when said members are moved toward the respective movable elements if all of said elements have been engaged by said holding means in predetermined positions of alignment with the respective members,

a bolt and a bolt thrower,

a lever connectable with said bolt thrower for extending and withdrawing said bolt,

and means coupling said lever to said set of members to move said members toward said elements when said lever is moved to connect it to said bolt thrower and to prevent said lever from connection to said bolt thrower unless said interfittable means are interfitted.

21. A lock in accordance with claim 20 wherein said ratchet and pawl means includes a ratchet to which said holding means is mounted.

22. A lock in accordance with claim 21 wherein said ratchet and pawl means further includes a pawl operated by axial movement of said arbor.

23. A lock in accordance with claim 22 wherein said pawl is mounted to a lever swung by axial movement of said arbor.

24. A lock in accordance with claim 23 wherein said *lever has a portion riding in a circumferential groove presented on means rotated by said arbor.

25. A lock in accordance with claim 24 which further includes a stop limiting axial movement of said arbor to an amount sufiicient to advance said holding means the dimension of one movable element.

26. A lock in accordace with claim 24 further including means preventing axial movement of said arbor except at certain predetermined angular positions thereof.

27. A lock in accordance with claim 26 wherein said preventing means includes a stud and an opening WhlCh must be aligned with one another for said arbor to be moved axially.

28. A lock in accordance with claim 22 which further includes means for returning said ratchet to a starting position in response to an axial movement imparted to said arbor the direction opposite that for advancing said ratchet.

29. A lock in accordance with claim 28 wherein the ratchet returning means includes a ratchet biasing spring and a pawl release cam.

30. A lock in accordance with claim 29 which further includes means for preventing such opposite axial movement of said arbor, except at a single predetermined angular position thereof.

31. A lock in accordance with claim 22 which further includes opposed springs biasing said arbor axially to astarting position.

32. In a combination lock including a set of movable tumbler elements, means for positioning said tumbler elements comprising,

rotatable cam means,

a set of cam followers biased toward engagement with said cam means,

means biasing said tumbler elements toward engagement with the respective cam followers for cammed movement therewith,

movable holding means engageable with the respective tumbler elements to prevent them from moving with the respective cam followers,

and means for advancing said holding means to cumulatively engage the respective tumbler elements one by one.

33. A lock in accordance with claim 32 wherein said holding means comprises a shaft insertable in openings in said tumbler elements.

34. A lock in accordance With claim 32 wherein the means advancing said holding means includes a ratchet advanced by axial motion imparted to a lock dial.

35. A lock in accordance with claim 32 which further includes structure permitting advancement of said holding means only at predetermined positions of said cam means.

36. A combination lock having a bolt,

a lever connectable to withdraw said bolt,

movable tumbler elements,

means for positioning the respective tumbler elements,

means for holding the respective tumbler elements against further movement when they have been positioned,

fence means blocking connection of said lever to withdraw said bolt unless said movable tumbler elements are held in predetermined positions of alignment with respect to said fence means and said fence means are interfitted with said tumbler elements at such positions,

means movably coupling said fence means to said lever for moving said fence means toward said tumbler elements in response to movement of said lever toward connection to withdraw said bolt, said coupling means permitting movement of said lever with respect to said fence means and tumbler elements when they are interfitted with one another,

and means preventing such moving of said fence means toward said tumbler elements until all of the respective tumbler elements are held by the holding means.

37. A combination lock in accordance with claim 36 wherein said fence means comprises a set of individual fence members fixed in staggered positions with respect to each other.

38. A combination lock in accordance with claim 37 which further includes means for changing the positions of said fence members with respect to one another to change the combination of the lock.

39. A combination lock having a bolt,

a lever connectable to withdraw said bolt,

a set of movable tumbler elements and dial-operated means for positioning said tumbler elements,

a set of fence members connected to said lever, each said fence member being associated with a respective tumbler element,

each said tumbler element presenting one of a gate and a tooth receivable in a gate, each said fence member presenting the other of the gate and tooth than the respective tumbler element,

means holding said fence members in predetermined positions with respect to one another,

selectively operable means for changing the positions of said fence members with respect to one another while said teeth are received in the respective gates,

and means for moving said lever relative to said fence members when said lever withdraws said bolt.

40. A lock in accordance with claim 39 which further includes means preventing contact between said fence members and tumbler elements until all of said tumbler elements have been positioned.

References Cited UNITED STATES PATENTS 86,908 2/1869 Cole et al 708O 247,250 9/1881 Hall 70-322 2,126,063 8/1938 Van Dine et al 7029 2,925,726 2/1960 Miller 70333 3,196,643 7/1965 Moss 70-133 3,357,216 12/1967 Cook 70313 3,383,887 5/1968 Harris et al 70305 3,416,337 12/1968 Hotchins 70284 FOREIGN PATENTS 16,822 1906 Great Britain.

MARVIN A. CHAMPION, Primary Examiner R. L. WOLFE, Assistant Examiner US. Cl. X.R. 70315

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