US3423970A - Combination lock mechanism - Google Patents

Description

Jan. 28, 1969 HARRELL I I 3,423,970

COMBINATION LOCK MECHANI SM Sheet g of5 Filed Feb. 23, 1967 J {g /3 nan 4 702:

v if .305 19/726544 FIG ,3 4 6 yzrazmer B. G. HARRELL.

Jan. 28, 1969 COMBINATION LOCK MECHANI SM Sheet Filed Feb. 25, 1967 Jan. 28, 1969 B. G. HARRELL COMBINATION LOCK MECHANISM Sheet Filed Feb. 23, 1967 FIG.6

FIGJI I 7 Claims ABSTRACT OF THE DISCLOSURE A combination lock mechanism having a plurality of rotary tumblers actuated by a dial from the exterior of the casing to align the gates in the tumblers so that a reversibly movable pawl carried on the inner portion of a locking bolt may be forced by reversing driver means first in a direction to cause a fence on the pawl to move into the aligned gates. Entry of the fence into the gates will unlock the bolt and allow the pawl to move in a direction to by-pass a stop pin by means of a by-pass slot in the pawl. Upon reversal of the driver means the pawl is shifted to reverse the direction of movement away from the tumblers to withdraw the pawl projection from the gates. When the unlocking pressure is removed from the bolt a spring will return the bolt to locking position and at the same time pull the pawl around the stop pin to its starting position ready to again strike the stop pin and prevent unlocking actuation of the bolt until the tumblers are again rotated to align the gates in the adjusted position where unlocking of the bolt may take place. During the pawl engagement in the aligned gates the tumblers are angularly displaced to a position removed from the initial position where the pawl fence first entered the gates so that reentry of the pawl fence is prevented after the pawl has passed around the stop pin on its movement to the starting position.

This improvement relates to combination type lock mechanisms having rotary combination discs or tumblers United States Patent and a pivoted bolt that is controlled by a simplified pawl and pawl driving means in association with the combination discs.

The combination lock mechanisms heretofore provided have required intricate components for scrambling the tumblers each time the lock is unlocked so that the gates are thrown out of alignment to prevent subsequent unlocking operation Without first dialing the proper combination.

The object of this improved lock mechanism is to avoid the complex construction of components, to eliminate certain components, and to simplify the construction of a combination lock without detriment to the security desired which is that of preventing unauthorized actuation.

A further object of this improved lock mechanism is to provide a simple pawl and stop means that will prevent picking the lock by feel of the tumbler gate positions.

In accordance With the foregoing brief description of the improved lock mechanism as preferred'construction will be hereinafter disclosed in connection with the accompanying drawings, wherein:

FIG. 1 is afragmentary front elevation of the present lock for a door post and door lock actuation rod to illus trate one embodiment of the invention;

FIG. 2 is a greatly enlarged sectional view taken at line 22 in FIG. 1 of the lock mechanism;

FIG. 3 is a view taken at line 33 in FIG. 2 with the pawl in its starting position;

FIG. 4 is a view similar to FIG. 3, but wherein the pawl fence has entered the gates in the tumblers;

FIG. 5 is another view similar to FIG. 3 but with the 3,423,970 Patented Jan. 28, 1969 bolt moved and the mechanism placed;

FIG. 6 is yet another view similar to FIG. 3 but with the bolt and pawl positioned for the return of the pawl about the outside of the stop pin;

FIG. 7 is a view similar to FIG. 6 to show one of the two positions of the pawl spring, the other position being that of FIG. 6;

FIGS. 8 and 9 are respectively side and end views of the bolt used in the mechanism of FIG. 2;

FIGS. 10 and 11 are respectively top and side views of the pawl associated with the bolt of the preceding views; and

FIG. 12 is a plan view of a passkey actuated cam member by which the mechanism heretofore shown may be unlocked without having to work the tumblers into alignment.

Referring to FIG. 1, the present combination lock mechanism 14 is shown mounted on a door or movable part 15 (such as a locker door) with its locking bolt 16 engaged in a notch 17 in a slide rod 18 carried by the door. The door cooperates with a fixed frame or part 19 (such as a locker frame member having a suitable notch to receive a catch 19' that hooks into the notch). The lock mechanism includes a rotary dial or knob 20 and an escutcheon plate 21 which holds the dial in position.

Turning now to FIGS. 2 and 3, the mechanism combines a combination lock with a cylinder lock mounted in a housing or case 22 having flanges 23 and 24 at opposite sides and an enlarged chamber 25 of generally rectangular shape. The chamber 25 opens at its central area into a well 26 having a suitably shaped bore 27. The case 22 is closed by a cover 28 which is substantially coextensive with the case flanges 23 and 24. The case 22 and cover 28 are positioned against the back side of the door or part 15, and suitable holes in the part 28 admit the insertion of mounting studs 29 which with threaded nuts 30 secure the face plate 31 at the front of part 15 and the case 22 at the back of part 15.

The lock case operatively receives a key operated cylinder lock 32 (FIG. 2) mounted in the bore 27 of well 26, and a tubular key receiving shaft 33 extends outwardly from the plug cylinder 32 through the chamber 25 to the cover 28. The cylinder 32 has the usual retractable prongs (not shown) which control rotation and it is retained in position axially of the bore 27 by a base plate 34 located by and secured in the bottom of the case chamber 25 by a plurality of rivet 0r headed elements shown at 35. Between the base plate 34 and cover 28 there are arranged on the tubular shaft 33 in stacked relation the'following parts: adjacent the base plate 34 is a key operated cam plate (FIG. 12), next a compression spring 36 is placed on the cam plate 80 to support the bottom most tumbler disc 37. A spacer 38 is placed on the tumbler 37 and the middle tumbler disc 39 is placed thereon, followed by a second spacer 40 and then the topmost tumbler disc 41 is placed next. A drive tube 42 connected to the tumbler 41 is received over the upper end of the tubular shaft 33, and the dial 20 is then mounted on the outer end of the drive tube 42. All of these parts are of known construction and are held in position by the compression spring 36. The tumblers 37, 39 and 41 are each formed with gate notches, such as the gate notch 43 shown in FIG. 3 for the top tumbler 41, and the peripheral edges of the tumblers are given an undulated shape to discourage picking attempts, as is well known.

Looking at FIGS. 2 and 3, it can be seen that the locking bolt 16 has one end 46 mounted on a pivot pin 47 securely positioned in the case 22, the other end 48 of the bolt 16 extends about the tumblers 37, 39 and 41 toward the opposite side from the pivot pin 47. As can correspondingly dis- 3 be seen in FIGS. 8 and 9 the locking bolt 16 is made up of a top plate 49, a center plate 50' and a bottom plate 51 of wider dimension than either plate 49 or 50. Thus, plate 51 has an inner circular edge 52 that is offset from the edge 53 of the two plates 49 and 50. The plates 49, 50 and 51 are held in assembly by rivets 54. The locking bolt 16 (FIG. 3) is urged into its locking position by the spring arm 55. The body 56 of the spring is mounted about pin 47, and the opposite arm 57 presses against the interior wall of the case chamber 25.

The arm 48 of the bolt 16 is apertured at 58 (FIG. 8) in plates 49 and 51 to receive a pivot element 59 (FIG. 3) that operatively connects the lug 60 (FIGS. and 11) of a pawl 61 between plates 49 and 51. The pawl 61 has an enlarged body 62 with a notch 63 formed in its bottom edge 64, and a fence portion 65 provided near the bevelled end 66 opposite the lug 60. The pawl body 62 is slotted at 67 to receive one arm 68 of a pawl actuating or drive means, such as a spring 69 mounted or coiled about the head end of the pivot element 59. The opposite arm 70 of the spring is formed with a looped end 71 which is free to engage at certain times the wall surface 72 and the wall surface 73 of the case chamber 25 to shift the direction of reaction of spring arm 68 upon the pawl 61 as will be set forth in more detail presently. The pawl 61 normally cooperates with stop pin 74 carried in the bottom of the case 22 adjacent the position where the tumbler gates are intended to come into aligned positions, and where the pawl fence 65 may enter the aligned gates. The wall of the case chamber 25 adjacent the stop pin 74 is recessed at 75 to allow for the pawl to pass between the pin 74 and the recess 75.

It is noted that when the tumbler gates or gate notches are misaligned the pawl fence 65 is prevented from moving inwardly of the peripheries of the tumblers and force applied on the bolt face 76 will only move the bolt 16 a very short distance to bring the bevelled face 66 of the pawl against the stop pin 74 to block or stop unlocking action of the bolt. Normally in the locked position the pawl spring 69 has its active end 71 engaged on wall surface 72 so that the arm 68 is stressed to pivot the pawl 61 in a clockwise direction (FIG. 3) about the pivot 59. At this time the fence rides on the peripheries of the tumblers 37, 39 and 41. When the end 71 of the pawl spring shifts with the locking bolt 16 so that it engages the wall 73 in the case 22 it changes the direction of force exerted by the arm 65 upon the pawl 61, and the pawl wants to pivot about pin 59 in a counterclockwise direction. The reversal of the force eifect exerted by the pawl drive means is an important feature of the mechanism.

Combination lock operation Having described above the components, parts and mechanism of the present lock assembly, reference will now be made to the views of the drawings, and particularly FIGS. 3 to 7 inclusive.

FIG. 3 illustrates the combination lock mechanism in which the tumblers 37, 39 and 41 have their gate notches, such as notch 43, scrambled so as not to be in aligned registration. At this time any force applied upwardly on the face 76 of the bolt 16 will effect a slight pivoting movement of the bolt about the axis of the pivot pin 47 which causes pawl movement also, until the bevelled face 66 on the pawl 61 strikes the stop pin 74 of the bolt 16 and is prevented from moving sufiiciently to permit the slide rod 18 to move upwardly far enough so that the surface 76 on the bolt 16 will allow the lock rod 18 to move sufliciently for unlocking purposes. During this slight permissive movement of the bolt 16 the end 71 on the pawl spring arm 70' will not break engagement with the wall surface 72, consequently the bolt 16 will be urged to pivot in a clockwise direction about the axis of the pivot pin 59.

In FIG. 4 it is assumed that the dial 20 has been correctly operably actuated to relatively rotate the tumblers 37, 39 and 41 so that the gate notches therein will all be in alignment. As this alignment occurs the force exerted on the pawl by the spring arm 68 will cause the pawl 61 to pivot in a clockwise direction, without any movement of the bolt 16, so that the fence 65 will enter the aligned notches. This action will remove the bevelled face 66 on the end of the pawl 61 from engagement with the stop pin 74, thereby allowing the bolt 16 to pivot without obstruction about its pivot 47. The bolt movement in its unlocking operation is shown by comparing FIGS. 4 and 5 As shown in FIG. 5 the bolt 16 has moved into a position where it is almost in a full unlocked position, and it is noted that in this position the notch 63 in the bottom edge 64 of the pawl body 62 (FIG. 11) will have moved into alignment with the stop pin 74. Concurrently with the alignment of the notch 63 and stop pin 74, the end 71 on the pawl spring arm 70 will have shifted its operative position from engagement on the wall surface 72 to engagement on the wall surface 73 in the chamber 25. The shifting of the engagement of the end 71 on the spring arm 70 will shift the direction of spring pressure applied by the opposite arm 68 on the pawl 61 and cause the pawl 61 to swing in a counterclockwise direction to the position shown in FIG. 6. The sequence of motion of the pawl 61 is shown partly in phantom outline in FIG. 6 and its fully retracted position is shown in full line.

In the motion of the locking bolt 16 between the positions shown in FIGS. 4 and 5, it will be understood that the tumblers 37, 39 and 41 will be rotated in unison to a new position (FIG. 5) where they will be left at the time the pawl spring shifts its direction of force on the pawl 61 and causes the pawl to move to the fully released position shown in FIG. 6. The locking bolt 16, it is noted, is at all times subject to the pressure from the arm 55 of a coil spring body 56. The spring arm 55 constantly urges the bolt 16 to pivot in a counterclockwise direction so as to normally want to assume its locked position.

In referring to FIG. 7 it can be seen that the spring arm 55 has caused the locking bolt 16 to move in a counterclockwise direction, and in doing this the pawl 61 is displaced from the position shown in FIG. 6 to a position as shown in FIG. 7 where the fence 65 thereon will now be out of registration with the gate notches in the several tumblers, and the gate notches 43 in the tumblers 37 and 39 have a shape different from the gate notches 43 in the tumbler 41. The relatively different shaped gate notches will prevent the fence 65 from reentering, and the amount of angular displacement experienced by the tumblers during the unlocking action of the bolt 16 will likewise prevent the fence 65 from automatically registering with the gate notches. Hence, once the bolt 16 has returned to its normal starting position (FIGS. 3 and 7) the pawl 61 will thereafter be blocked from allowing the bolt 16 to move to unlock because its bevelled face 66 will strike the stop pin 74. It is always recommended when using a combination lock, to give the dial an extra spin when the mechanism is returned to its intended locked position so that there will be very little likelihood of leaving the gate notches in the tumblers near the position of alignment. The precaution makes it necessary to have the proper combination whereby the tumblers at some future time can be again brought into gate notch alignment.

The foregoing operation of the combination lock mechanism has set forth the important characteristics wherein the pawl drive means or spring 69 is made to perform two functions by means of changing its direction of applied force. In FIG. 4 the pawl spring 69 is in its position to force the pawl 61 to move in a clockwise direction for unlocking the bolt 16. The unlocking action of the bolt 16 causes the pawl 61 and the spring 69 to move through intermediate positions of FIGS. 5 and 6 where the pawl 61 displaces the tumblers and then leaves the tumblers and passes outwardly around the backside (referring to the relative position of the tumblers and the stop pin) of the stop pin 74 due to the change of direction of the pawl spring 69 and particularly of the spring arm 68. When the pawl 61 reaches the position of FIG. 6, the pawl and the bolt will be in position to return to the starting locked condition as is shown in FIGS. 7 and 3. FIG. 7 shows an intermediate position and FIG. 3 shows the normal locked position of the components and parts.

Cylinder lock operation It has been heretofore pointed out that the present lock mechanism includes a cylinder lock 32 mounted in the well 26 of the case 22. In order to operate the cylinder lock 32, the tubular shaft 33 which extends through the chamber 25 of the case 22 is formed with a suitable slot 77 for the reception of a key (not shown) through the center of the dial 20. The insertion of the key in the slot 77 will draw in the projecting prongs and permit the cylinder 32 to be rotated in the well 26, and rotation of the tubular shaft 33 will cause the key cam 80 (FIG. 12) to be rotated because the key cam 80 is formed with a pair of nibs 78 that fit into longitudinal and similarly shaped grooves 79 (FIG. 2) in the opposite sides of the tubular shaft 33. Thus, the key cam 80 is keyed to the tubular shaft 33 and may be driven by it when the proper key is inserted in the slot 77. The purpose for the key cam 80 is to permit only persons who have authorized possession of the proper key to bypass the combination lock mechanism and unlock the bolt 16. This is accomplished by turning the key slot 77 from the position shown in FIG. 6, where the cam lobe 80 is in corresponding position, to the position shown in FIG. 7 where the cam lobe 80 has been moved approximately 90 in a clockwise direction to strike the surface 81 (FIG. 11) on the pawl body 62. The engagement of the cam lobe 80 with the surface 81 on the pawl body will cause the pawl 81 to be lifted from the full line position of FIG. 7 to the fragmentary dotted line view of FIG. 7 where it can be seen that the bevelled face 6-6 on the outer end of the pawl has been lifted above the stop pin 74. This is all that is required to unlock the bolt 16.

The foregoing description has set forth the components and parts of the improved combination lock mechanism, and has set forth the cooperation between a combination lock mechanism and a cylinder lock mechanism for effectively bypassing the combination lock mechanism when it is desired to do so under authorized conditions. There has also been disclosed a combination lock mechanism that has an organization of parts and elements which provide a unique and novel way of utilizing a pawl for scrambling the set of tumblers and for preventing unlocking action of the usual locking bolt. Furthermore, there has been herein disclosed a structure for effective operation of a combination lock pawl for two different purposes by the unique incorporation of a driving member that is able to drive the pawl in opposite directions in response to movement of the usual locking bolt. It is, of course, understood that changes and modifications may occur to those skilled in this art, and it is intended to cover such modifications and changes within the spirit and scope of the annexed claims.

What is claimed is:

1. In a combination lock, a case, a locking bolt pivotally mounted in said case and having a part extending outwardly of said case, said bolt being movable between locking and unlocking positions, a pawl pivotally mounted on said bolt within said case and movable with and relative to said bolt, a stop element in said case in position to block movement of said pawl with said bolt and prevent movement of said bolt into unlocking position, a plurality of combination discs operable in said case to normally maintain said pawl against movement relative to said bolt but adjustable to permit such relative movement, and drive means connected to said pawl having a first position urging said pawl to move in one direction relative to said bolt upon adjustment of said combination discs and bypass said stop element, said drive means being movable, in response to bolt movement into unlocking position, into a second position to reverse the urging motion of said pawl relative to said bolt to cause said pawl to bypass said stop element upon bolt return movement into locking position.

2. The combination lock set forth in claim 1 wherein said drive means has one arm engaged on said pawl and a second arm in position to engage different portions of said case in response to said bolt being in locking and unlocking position, said drive means engagement with said case developing its urging effect upon said pawl.

3. The combination lock set forth in claim 1 wherein said pawl is formed with a surface engage-able on said stop element to block bolt movement toward unlocking position, and said pawl is formed with a notch in position, upon said bolt reaching its unlocking position, to permit said pawl to pass said stop element upon reverse motion of said pawl.

4. The combination lock set forth in claim 1 wherein said drive means is a spring member having one arm engaged on said pawl and having a second arm extending into engagement on said case, movement of said bolt and pawl between bolt locking and unlocking positions causing said second arm to stress said first arm to drive said pawl.

5. The combination lock set forth in claim 1 wherein said plurality of combination discs are provided with gate notches movable into alignment upon combination disc adjustment, and said pawl is provided with a fence in position to be driven into engagement with said aligned gate notches by said drive means, said fence displacing said discs upon bolt movement into unlocking position and said drive means upon movement into said second position reversing the drive on said pawl to extract said fence from said gate notches and prevent re-engagement thereof.

6. In a combination lock, a case, combination tumbler discs operable in said case and having gate notches movable between a first position preventing unlocking and an adjusted aligned second position where the lock may be unlocked, a manual control member projecting from said case permitting said tumbler discs to be moved out of said first position such that said gate notches are moved to said adjusted aligned second position, a bolt operably mounted in said case for movement between locked and unlocked positions, spring means normally urging said bolt into its locked position, and a reversible power operated pawl carried by said bolt, said pawl having a fence thereon, said pawl and fence normally in the second position of said tumbler discs being urged by said pawl into said aligned gate notches to permit bolt movement toward its unlocked position and tumbler disc movement into locked position, movement of said bolt into unlocked position causing said pawl to reverse its powered operation and withdraw its fence, said bolt spring returning said bolt to its locked position.

7. The combination lock set forth in claim 6 wherein the reversible power for said pawl is a spring having one arm engaged on said pawl and another arm movable in said case to engage different portions of said case for changing the direction of spring reaction of said one arm on said pawl.

References Cited UNITED STATES PATENTS 1,956,069 4/1934 Hill 70293 2,775,115 12/1956 Bremer 70133 3,176,486 4/1965 Richardson 70133 MARVIN A. CHAMPION, Primary Examiner. EDWARD J. MCCARTHY, Assistant Examiner.

US. Cl. X.R.

Images