US2767572A - Combination lock - Google Patents

Description

United States Patent COMBINATION LOCK Harry C. Miller, Rochester, N. Y.

Original application October 3, 19$1, Serial No. 249,495L Divided and this application November 17, 1955, Serial No. 547,522

7 Claims. (Cl. 70-333) This invention relates to improvements in permutation locks, commonly referred to as combination locks.

This application covers improvements in the lock disclosed in my Patent No. 2,575,674 dated November 20, 1951, and is a division of my copending application Serial No. 249,495, filed October 3, 1951.

Locks of the type commonly referred to as combination locks are, of course, very well known. Also it is generally known that such locks depend for their operation upon the alignment of a plurality of elements in a preselected manner which permits the operation of a bolt. These elements are usually in the form of discs, commonly called tumblers, each of which is provided with a notch or recess, called a gate, the alignment of the gate determining when the bolt can be moved. It is common for these locks to be provided with three discs, although more could be used. The security of such locks is dependent upon the fact that the number of orders or permutations of the possible relative positions of each disc before all of the gates come into register, which gives the correct combination, is so large that the chances of these notches or gates being aligned by a person not familiar with the combination is so small as to negligible.

The tumblers are operated through means of a member commonly referred to as a drive wheel or driving cam which also has a special gate. An element called a fence mounted on a pivoted fence-lever extends transversely across the edges of all of the tumblers and is adapted to drop into the gates when all of the gates in the tumblers are in alignment and when the drive wheel is manipulated to permit the fence-lever to drop. Conventionally, the fence is held in such a position that it is slightly spaced from the outer peripheries of all of the tumblers. However, because of the difiiculty in manufacture, it is almost impossible to manufacture all of the parts, including the tumblers, to such close tolerances that there will be the same slight difference in the space between the outer edges of the difierent tumblers and the fence. Accordingly, by a very careful manipulation of the drive wheel to a position such that the fence drops against the edge of the highest tumbler, a skilled person can detect by feel or by a very minute sound or click when one of the gates is aligned with the fence. Then by continuing to manipulate the drive wheel by means of the dial, the gate of the next highest tumbler can be aligned with the fence and, therefore, with the gate of the first tumbler, and so on until the correct combination is found and the security of the lock is broken. Accordingly, heretofore, because of the defects generally mentioned above, the security of a so-called combination lock against a skilled person has been limited.

In accordance with the present invention, means are provided for preventing the fence-lever from contacting the drive wheel and seating in the special gate therein. Furthermore, the fence-lever can be dropped into contact with the drive wheel and enter the special gate only when this drive wheel gate is substantially aligned with the fence. This avoids a defect of prior devices in that the drive wheel cannot be turned suificiently to manipu- 2,767,572 Patented Oct, 23, 1956 Ice late the tumblers when the drive wheel is in contact with the fence-lever.

Also, in order to insure that the tumbler-s cannot be vibrated or walked by oscillating the drive wheel over its limited arc of movement, interlocking means are provided in the form of serrations on the fence and on the peripheries of the tumblers so that as soon as the fencelever is permitted to seat in the drive wheel gate, the fence rests on the tumblers with their serrated surfaces inter-engaged, rendering manipulation of the tumblers practically impossible.

The primary object of the present invention is to provide a combination lock in which a manipulation of the dial will not give any indication of the position of the gates in any of the tumblers.

Another object is to provide a combination lock with a drive wheel having means for selectively preventing the fence lever from seating in the drive wheel gate and for permitting rotation of the drive wheel only when the fence is held away from the peripheries of the tumblers.

Another object is to provide a combination lock in which the drive wheel cannot be rotated to manipulate the tumblers when the fence lever is in position to contact the drive wheel.

Another object of the present invention is the provision of a combination lock having interlock means maintaining the fence out of contact with the tumblers at all times except when the fence is substantially aligned with the drive wheel gate.

Another object is to provide a combination lock in which the drive wheel cannot be rotated to manipulate the tumblers when the fence lever is in position to engage the drive wheel and having interlocking means between the tumblers and the fence to prevent the walking of the tumblers when the fence lever is positioned to engage the drive wheel.

A still further object is to provide an improved combination lock in whichthe fence can be held in spaced relation to the outer edges of all of the tumblers until the gates in all of the tumblers are brought into alignment.

Another object of the present invention is the provision of a novel combination lock which is normally biased to a condition maintaining the fence-lever out of contact with the'drive wheel gate, and which can be actuated to engage these elements only when the drive wheel gate and tumbler gates are substantially aligned with the fence.

Other objects, advantages, and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, wherein several preferred embodiments of the invention are shown.

In the drawings:

Figure 1 is a horizontal section of a combination lock embodying the present invention, taken along line 11 of Fig. 2;

Figure 2 is a vertical longitudinal section illustrating the sliding bolt and associated components of the combination lock shown in Figure 1, taken along the line 2-2 of Figure 1; and

Figure 3 is a vertical longitudinal section of the lock illustrated in Figure 1, showing the lock conditioned with the fence seated in the tumbler gates, and taken along the line 22 of Figure 1.

Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, the combination lock of the present invention comprises a casing 11 housing the lock mechanism including a plurality of tumblers 16, 17 and 18 supported for rotation therein. The casing 11 is secured to the door 13 by suitable screws or like fastening means.

80"on the fence arm 80.

ing 11 through gate 85a can only An operating shaft or spindle 21 extends through an accommodating bore in the door 13 and has affixed thereto at its outer end a dial 23 having a dial knob 23a thereon. The dial 23, in accordance with conventional practice, is adapted to be accommodated in a recess in an escutcheonplate 19'afiixed'to the door 13 and in cooperation with the spindle21 serves as the means for manipulating the tumblers 16, 17 and 18.

A sliding bolt 75 projects from the casing 11, and a plate 76 integralwith the bolt 75 extends into the casing and around the shaft 21, The shaft 21 is'provide'd with a bearing sleeve 77 having an annular recess to accommodate a suitable slot 76" in the inwardly projecting bolt plate 76. The sleeve 77 therefore serves as a guide for the bolt 76 in cooperation with a guide screw 78 having a head overlying and contacting a beveled "portion 76" along the lower surface of the plate 76 to confine the bolt to rectilinear movement.

A fence-lever 79 is pivotally mounted by means of a pivot screw 79' to the inner wall of the lock housing 11 and provided with a fence arm 80 projecting toward the shaft 21 and extending through substantially the depth of the lock housing. The outer surface of the arm 80 adjacent the tumblers 16, 17 and "18 forms the fence cooperating with the tumblers. The pivot fence lever 79 is likewise provided with an upwardly extending arm 81 forming an operating arm therefor normally in abutment with a suitableresiliently biased pin 82 projecting slightly from an inwardly disposed face of the bolt 75 to bias the fence-lever 79 in a counterclockwise direction as viewed in Fig. 2. An outstruck lug or shoulder 83 is provided in thebolt plate 76 disposed to be engaged by the operating arm 81 of the fence lever 79 on counterclockwise rotation to retract the bolt 75 from locking position. This lock is provided with a drive wheel 85 disposed forwardly of the tumblers 16, 17 "and 18 in the direction of the forward wall of the lock housing 11 and is provided with a suitable driving stud 85 adapted to engage the projecting detent 27a of a conventional fiyer 27 associated with tumbler 16.-

The drive wheel 85, shaft 21 and dial 23 are'normally biased in rearwardlyprojected position with the drive wheel adjacent the tumbler 16 by means of a suitable coil spring 86 surrounding the shaft 21and extending into a suitable annular recess formed in the sleeve 77, the opposite end of the coil spring 86 being disposed against the adjacent face of the drive wheel 85. The drive wheel 85 is provided with a gate 85a of com ventional form adapted to accommodate a projecting lip drive wheel 85 from position indicated in Fig. 2 will progressively effect seating of the lip 80' in the drive wheel gate 85a and rotates the fence lever 79 counterclockwise to cam the bolt 75 inwardly of the lock housinteraction of the operating arm 81 and Entrance of the lip 80 into the drive wheel be elfected, of course, when thegates of the tumblers 16, 17 and 18 are likewise in alignment with the drive wheel gate.

A fixed L-shaped stud 87 projects rearwardly from the front wall of the housing 11' through the opening 76' of the bolt plate 76 and terminates adjacentthe front face of the drive wheel 85. The drive wheel 85 is lug 83.

provided with a suitable arcuate slot 88 in registry with the fixed stud 87 throughout a preselected arc of rotation of the drive wheel 85 and an enlarged portion 88' is formed at one end of the slot to accommodate the head of the L-shaped stud 87 for entrance ofthe stud 87 through the slot 88. The stud 87 prevents movement of the drive wheel 85 and shaft 21 outwardly of the lock except when the enlarged portion 88' otthe slot 88 is in registry with the head of the stud 87. In this position, the shaft 21 and drive wheel 85 can be withdrawn towards the front of the housing against the bias of the spring 86 and rotated through the limit of the arc defined by theslot 88. Only in this withdrawn position Clockwise rotation of the of the drive wheel 85 is the projecting fence portion 80' disposed to contact the periphery of the drive wheel 85 and'seat in the gate 85a thereof.

The protective interlocking means of this embodiment comprises a cylindrical operating element 90 threaded to the shaft 21 and extending to the rear cover plate 91 of the housing 11 and through a bore formed in a tubular boss 91' formed thereon. The tubular boss 91' in this embodiment is the supporting element about which the,

tumblers are journaled. The cylindrical operating element 9?- is provided with a beveled or tapered end 90' disposed at the rearwardly disposed end thereof. The cover plate 91 of the housing 11 is provided with a pair of guide lugs 92 having radially aligned bores therein through which a sliding pin 93 is extended and arranged for radial movement. A suitable coil Spring 94 extends around the sliding pin 93 between the guide lugs 92 and biases the pin 93 on a radial axis inwardly toward the cylindrical operating element 90. The outer end of the sliding pin 93 projects outwardly of the outer lug 92 and is disposed in contact with a lateral projection 80" integrally formed on the fence arm 80.

With the shaft 21 normally projected rearwardly within the lock housing 11, the inner end of the sliding pin 93 normally bears on the cylindrical periphery of the operating element 90 maintaining the pin 92 in the outwardly projected position illustrated in Fig. 1 against the bias of the spring 94. In this position the pin 93 hearing against the lateral projection 80 of the fence-lever 79 maintains the fence arm 80 out of contact with the peripheries of the tumblers 16, 17 and 18 and drive wheel 85. However, when the tumbler gates have been aligned through proper clockwise and counterclockwise rotation of the dial 23, and the shaft 21 are shifted outwardly of the housing to project the stud 87 through the enlarged portion of the slot 88, the tapered or beveled end portion 90 of the operating element 90 is brought into registry with the inner end of the sliding pin 93. Such movement of the operating element 90 permits the pin 93 to be shifted radially inwardly toward the axis of the shaft 21 under the resilient bias of the spring 94, withdrawing the outer end of the pin 93 from contact with the projection 80 on the fence arm 80 and permitting the fence to be rotated into the gates of the tumblers 16, 17 and 18 and lip 80 thereof to be seated in the drive wheel gate 85a under the counterclockwise bias on the fence-lever 79. Projection of the shaft 21 and drive wheels 85 inwardly again earns the pin 93 radially outwardly through interaction with the tapered portion 90 of the operating element 90,rotating the fence-lever 79 out of contact with the tumbler peripheries.

From the foregoing description it will be seen that the present invention provides an improvement in combination locks which clearly adds to the security thereof and which is relatively inexpensive to manufacture. Although the invention has been described in considerable detail, it will be apparent to those skilled in the art that many variations are possible without departing from the inventive concept. Therefore, while I have particularly shown and described but one specific embodiment of the invention, it is distinctly understood that the invention is not limited thereto, but that various modifications may be made without departing from the spirit and scope thereof, andit is desired therefore, that only such limitations shall be placed thereon as are imposed by the prior art and are set forth in the appended claims.

I claim:

1. A combination lock comprising a plurality of peripherally recessed tumblers, a drive wheel for adjusting said tumblers, an operating shaft rigidly coupled with the drive wheel, a bolt, a fence-lever for operating said bolt having fence means overlying said tumblers and a nose for selectively engaging the periphery of said drive wheel, said drive Wheel having gate means to accommodate said nose and permit said fence means to seat in said tumbler recesses for moving said bolt, means for and drive wheel 85.

continuously urging the nose of said fence lever into engagement with the periphery of said drive wheel, means for axially shifting said shaft and drive wheel, means biasing said drive wheel toward said tumblers, a tapered cam on said shaft, a sliding pin extending between said tapered cam and said fence lever biased toward said cam, said pin normally riding on the larger diameter portion of said cam to maintain said lever and fence out of contact with said drive wheel and tumblers, said pin being biased away from said fence lever on axial shifting of said shaft and registry of the smaller diameter portion of said cam with said pin to permit operative coupling of said nose with said drive wheel gate and seating of said fence in said tumbler recesses.

2,. A combination lock comprising a plurality of peripherally recessed tumblers, a drive whel for adjusting said tumblers, an operating shaft rigidly coupled with the drive wheel and projecting in opposite directions therefrom, dial means alfixed on one end of said operating shaft, a bolt, a fence-lever for operating said bolt having fence means overlying said tumblers and a nose for selectively engaging the periphery of said drive wheel, said drive wheel having gate means to accommodate said nose and permit said fence means to seat in said tumbler recesses for moving said bolt, means for continuously urging the nose of said fence lever into engagement with the periphery of said drive wheel means for axially shifting said shaft and drive Wheel, means biasing said drive wheel toward said tumblers, said shaft terminating remote from said dial means in inclined surface means converging toward the axis of said shaft, radially shiftable means extending radially of said shaft between said shaft and said fence-lever, means biasing said radially shiftable means toward engagement with said inclined surface means, said inclined surface means normally positioning said radially shiftable means to space said fencelever and fence out of contact with said drive wheel and tumblers and shifting said radially shiftable means toward the axis of said operating shaft when said shaft is displaced axially from its normal position to permit operative coupling of said fence lever nose in said drive wheel gate.

3. A combination lock comprising a plurality of peripherally recessed tumblers, an operating shaft extending coaxially of said tumblers and projecting rearwardly thereof, a drive wheel intermediately positioned on said operating shaft and rigidly connected thereto forwardly of said tumblers for adjusting said tumblers, dial means fixed to said shaft opposite said projecting end, a bolt, a fence-lever for operating said bolt having fence means overlying the tumbler peripheries and a nose for selectively engaging the periphery of said drive wheel, said drive wheel having a peripheral gate for accommodating said nose and permitting said fence means to seat in said tumbler recesses for moving said bolt, means for continuously biasing said fence lever nose into engagement with the periphery of said drive wheel means for axially shifting said shaft and drive wheel, means having a pro jecting shoulder radially aligned with said projecting portion of said shaft, said projecting shaft portion having a cam surface inclined in converging relation to the axis of said shaft, and cam follower means extending between said cam surface and said projecting shoulder of said fence means biased to engage said cam surface, said cam surface positioning said cam follower means to space said fence-lever and fence out of contact with said drive wheel and tumblers when said operating shaft is positioned at one limit of axial movement and shifting said cam follower means upon axial movement of said shaft toward its other limit of movement to permit operative coupling of said fence-lever nose in said drive wheel gate means and seating of said fence in said tumbler recesses.

4. A combination lock comprising a plurality of peripherally recessed tumblers, an operating shaft extending coaxially of said tumblers and projecting rearwardly thereof, a drive wheel intermediately positioned on said operating shaft and rigidly connected thereto forwardly of said tumblers for adjusting said tumblers, dial means fixed to said shaft opposite said projecting end, a bolt, a fence-lever for operating said bolt having fence means overlying the tumbler peripheries and a nose for selectively engaging the periphery of said drive wheel, said drive wheel having a peripheral gate for accommodating said nose and permitting said fence means to seat in said tumbler recesses for moving said bolt, means for continuously biasing said fence lever nose into engagement with the periphery of said drive wheel means for axially shifting said shaft and drive wheel, means biasing said drive wheel toward said tumblers, said fence means having a projecting shoulder radially aligned with said projecting portion of said shaft, said projecting shaft portion terminating rearwardly in a frusto-conical surface converging toward the axis and rear end of said shaft, and a pin extending between said frusto-conical surface and said projecting shoulder of said fence means and biased to engage the former, said shaft being normally disposed under the influence of said biasing means at a first limit of axial movement positioning said pin in engagement with said shaft immediately adjacent said frusto-conical surface to support said fence-lever and fence spaced out of contact with said drive wheel and tumblers during adjustment of the tumblers, said pin being shifted axially under the influence of said frusto-conical surface in engaging relation therewith upon movement of said shaft toward a second and opposite limit of axial movement to discontinue supporting association with said fence-lever and permit operative coupling of said fence-lever nose in said drive wheel gate means and seating of said fence in said tumbler recesses.

5. In a combination lock, the combination recited in claim 3 including means for restraining said drive wheel against rotation from a preselected fixed position of orientation during non-registry of said drive wheel with either of said limits of axial movement and substantially throughout travel of said drive wheel between said two limits, and means releasing said drive Wheel for rotation when said drive wheel is positioned at either of said two limits of axial movement.

6. In a combination lock, the combination recited in claim 4 including means for restraining said drive wheel against rotation from a preselected fixed position of orientation during non-registry of said drive wheel with either of said limits of axial movement and substantially throughout travel of said drive wheel between said two limits, and means releasing said drive wheel for rotation when said drive wheel is positioned at either of said two limits of axial movement.

7. In a combination lock having peripherally recessed tumblers, an operating shaft, a peripherally recessed rotatable driving wheel fixed to said operating shaft, dial means fixed to said operating shaft, means for axially shifting said operating shaft and drive wheel between two spaced positions of axial adjustment, said drive wheel having means for adjusting said tumblers when said drive wheel is positioned at one of said positions of axial adjustment, a bolt, a fence-lever for operating said bolt having fence means overlying the tumbler peripheries and a fence-lever nose for selectively engaging the periphery of said drive wheel, said drive wheel having a peripheral gate for accommodating said nose and permitting said fence means to seat in said tumbler recesses for moving said bolt and spring means bearing against said fence lever for continuously biasing said fence lever nose into engagement with the periphery of said drive wheel; the improvement of which comprises a frustoconical cam surface terminally located on said shaft rearwardly of said tumblers converging rearwardly toward the axis of said shaft, cam follower means shiftable along an axis extending radially of said shaft, said cam follower means extending between said shaft and said fence-lever,

means biasing said cam follower means to engage said cam surface, saidscam rfollower means normally riding on thelarger diameter portion of said cam surface to maintain said fence-lever and fence out of contact with said drive wheel and tumblers and being shifted away from said fenceleveronaxial shifting of said operating shaft E and registry of the smaller diameter portion of said cam surface with said cam follower means to permitroperating coupling of said fence-lever nose with said drive Wheel gate means and seating of said fence means in said 5 tumbler recesses.

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