US 3664231 A
There is disclosed a combination lock which is actuated by two sets of numbered keys. Contained within the lock is a tape which is pre-punched with a succession of randomly generated codes. The lock can be actuated only when the keys punched by the user correspond with the code on the punched tape. Each actuation of the lock advances the tape to establish a new code.
Description (OCR text may contain errors)
[451 May 23, 1972 United States Patent Hanson  LOCKING DEVICE  Inventor:
Walter J. Hanson, Old Greenwich, Conn.
Pitney-Bowes, Inc., Stanford, Conn.
Dec. 17, 1970  Assignee:
 Appl. No.: 98,999 Primary Examiner-Albert G. Craig, Jr.
' Attomey-William D. Soltow, .lr., Albert W. Scribner, Martin D. Wittstein and Louis A. Tirelli m c 7 w 5 e n Em fi man Ba ME 9 2 5 1 7 6 2 .26 m 3 s8 /6001 u. 0 2 "n W mm 2-02 m a BMJm mm 0 "u m m mm nl A n 5 "0 wk N. 1 7 C n B m m 5 m .m m8 m E ma m A 4 m m r T rm 1 H .m S ea B m m m D vK .m M NE E ho n c7 4 Q N i we U 1 in m d Ld 59 n 91. I 1.] 1. MW 3% 6,9, [.l 22
ABSTRACT There is disclosed a combination lock which is actuated by two sets of numbered keys. Contained within the lock is a tape which is pre-punched with a succession of randomly generated codes. The lock can be actuated only when the keys punched by the user correspond with the code on the punched tape. Each actuation of the lock advances the tape to establish a 22 Claims, 15 Drawing Figures PATENTEBMAY 23 I972 SHEET 1 [IF PfxTENTEDMM 23 1972 SHEET 2 BF 8 INVENTOR. WALTER J. HANSON PATENTEUMM 23 I972 SHEET 3 BF 8 INVENTOR. WALTER .J. HANSON PATEF-1TEU'MAY23 19-12 3 664, 2 31 sum 4 OF 8 INVENTOR. WALTER J. HANSON www WW \ww ATTORNEY PATENTEDHAY 23 1972 SHEET 5 [1F 8 465 %64 1501; 1&9
PATENT ED MAY 2 3 I972 SHEEI 8 BF 8 mm m1) MHWHHHHHI INVENTOR. WALTER J. HANSON i the following description and appended claims.
1 LOCKING DEVICE BACKGROUND OF THE INVENTION There are a number of applications in which it would be desirable to have a combination lock which would automatically change its combination upon each actuation. One such application is in postage meters. At the present time, when the postage value of a meter has been used, it is necessary to physically carry it to a post office where the meter is reset to the correct amount. This could be avoided if the postage meter included a combination lock whose combination changed upon each usage. This would make it possible, for example, to mail a check or otherwise provide for the proper credit and then obtain by telephone the combination required to actuate the lock and reset the meter by a predetermined amount. The combination would then change and the succeeding combination would be available only after another unit of postage has been paid for.
Locks with automatically changing combinations have been proposed in the past. One, for example, is disclosed in U.S. Pat. No. 3,034,329 which issued May l5, I962 to R. C. Pitney et al. Locks of that nature, although important advances over the state of the art, retain certain disadvantages which it would be desirable to overcome. For example, the combination of such a lock is determined by the mechanical elements of the lock itself. This makes it difficult to alter the combination sequences. It also requires rather complex mechanical elements, causing the lock to be larger and more expensive than would be desirable.
Accordingly, it is an object of the present invention to provide an improved combination lock'of simple construction which can be easily mass produced. Other objects are to provvide such a lock wherein the sequence of combinations is established by punched tape which is easily replaced. Other objects, features, and advantages will become apparent from SUMMARY OF THE INVENTION In accordance with the present invention there is provided a combination lock including an actuating member which can be unlocked upon entry of the correct combination therein. The lock includes combination determining means selectively positionable in the lock and defining apertures representing elements of a preselected combination. A plurality of sensing means are individually advanceable against the combination determining means and are positioned to enter any aperture which is aligned therewith. The lock includes a plurality of manual selection means, each of which corresponds to one of the sensing means and is independently movable to represent elements of a selected combination. A linkage interconnects each of the selection means and its corresponding sensing means and is adapted to assume a clearing position when an element of the selected combination corresponds to an element of the preselected combination and a blocking position in the absence of such correspondence. Means are provided for normally blocking the actuating member but releasing it when all of the linkage means are in their clearing positions.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view on a reduced scale of a postage meter incorporating a combination lock in accordance with this invention;
FIG. 2 is a plan view of the combination lock of this invention with a portion of the housing broken away to illustrate its internal construction;
FIG. 3 is a cross section taken substantially along line 3-3 of FIG. 2;
FIG. 4 is a cross section on an enlarged scale taken substantially along line 44 of FIG. 3;
FIG. 5 is a cross section on an enlarged scale taken substantially along line 55 of FIG. 3;
FIG. 6 is a cross section on an enlarged scale taken substantially along the line 6-6 of FIG. 3;
FIG. 7 is a cross section taken substantially along the line 7-7 of FIG. 3;
FIG. 8 illustrates a portion of the tape advance mechanism of the invention;
FIG. 9 is a perspective view of the sensing gate mechanism of the invention;
FIG. 10 is a perspective view of the release bar mechanism of the invention;
FIG. 11 is a cross section taken substantially along the line 1lll ofFIG. 5;
FIG. 12 is an illustration depicting the manner in which an improper combination keeps the lock in its locked position;
FIG. 13 illustrates the manner in which a proper combination unlocks the lock;
FIG. 14 is a timing chart illustrating the various steps in operation of the lock of the invention; and
FIG. 15 is an elevational view illustrating a modified version of the gate.
DESCRIPTION OF THE PREFERRED EMBODIMENT There is illustrated in FIG. 1 a postage meter M to which is secured the combination lock L of this invention. Mounted on the side of lockLis an input knob 10. This knob when rotated sets into the meter M a preselected amount of postage. The lock, however, permits turning of the knob only when a correct combination is selected. Positioned on the top of lock L are two sets 12, 14 of numbered buttons. The buttons of each set carry the digits I-9 and the two sets may be differentiated by color. For example, buttons 12 may be white and buttons 14 red.
Referring now to FIGS. 2-5, the lock will be seen to comprise an inner side frame 16 and an outer side frame 18 connected together in spaced parallel relationship by means of conventional boIt-nut-spacer assemblies 20. Also mounted to these assemblies is back plate 22 and housing 24. Extending between the side frames 16, 18 is a top plate 26 which is parallel to and spaced below the top of the housing. Parallel to, and spaced below, the top plate 26 is a guide plate 28. The top plate 26 and guide plate 28 each defines a total of 18 slots. These slots are aligned to retain therein the key stems of the button sets 12, 14 as will now be described.
Button sets 12 and 14 are substantially identical. Each comprises a total of 9 key stems, 121-129 and 141-149. Each key stem is topped by a suitable button 120, 140. Only two types of key stems are required for all the eighteen keys. Those keys which form the center row of each set, namely, I22, 125, 128 and 142, 145, 148 are straight and their lower ends are positioned directly beneath the corresponding buttons as shown in FIG. 3. The key stems of those keys forming the outside rows ofeach set, namely, 121, 123, 124, 126, 127, 129, 1, 3, 4, 6, 7, 9 have their lower extremities cut at an angle in order that the bottom ends of all keys in each set are aligned as shown in FIG. 3. All the angled key stems are identical. Each key stem is stamped to form a central tongue 30 having a detent 32 therein (FIG. 6) which coacts with the top plate 26 to retain a key either in a raised or lowered position.
The lower end of each key stem carries a pivot 34. Supported by the pivots 34 on the stems of key set 12 is a set 36 of tumbler levers. The individual tumbler levers 361-369 correspond respectively to the key stems 121-129. A similar set 38 of tumbler levers are mounted on the pivots 34 of the stems of key set 14. The individual tumbler levers 381-389 correspond respectively to the key stems 141-149. The tumbler levers are identical although reversed in each set. Their construction is best seen in FIGS. 12 and 13. They are elongated and pivoted at approximately their center points. At their inner ends, each lever is formed with an offset T head 40.
A pair of shafts 42, 44 extend horizontally between the inner and outer side frames. Pivotally mounted on shaft 42 is a set 46 of sensing members 461-469. A similar set 48 of sensing members 481-489 is mounted on shaft 44. The sensing members override a plate 50 which is slotted to restrain them to vertical movement only. The sensing members are identical although the two sets are reversed. The construction of the sensing members is most clearly illustrated in FIGS. 12 and 13 which portray members 468, 488. Each member includes an elongated inwardly extending body portion which terminates in a downwardly dependent sensing finger 52. An upwardly extending portion of the member defines a horizontal slot 54 which loosely engages the offset T 40 of its corresponding tumbler lever. Below the slotted portion of each sensing member is a shoulder 56. The opposite ends of the sensing members extend beyond the pivot and are provided with a horizontal lever arm 58 and a vertical lever arm 60. Each of lever arms 58 of sensing member set 46 is engaged by a horizontal leaf spring 62. Each vertical lever arm 60 of the sensing member set 48 is engaged by a vertical leaf spring 64. These leaf springs bias the corresponding sensing members causing sensing fingers 52 to be urged downwardly through an opening 66 in plate 50. Positioned directly below the opening 66 is a punched computer tape 68 supported by a tape support plate 70 defining two parallel rows of 9 holes 72 (FIG. 7) aligned with sensing fingers 52.
The knob on the side of the lock is secured to the end of a combination drive and cam shaft 74. The shaft 74 extends through the lock to actuate a meter input mechanism 76. Mounted upon shaft 74 are a plurality of cams and other elements which will now be described.
Mounted on shaft 74 on the outside of side frames 16, 18 are a pair of identical sense release cams 78a, b. These cams control the vertical position ofa sense release bar 80 which extends through suitable openings in the side frames and lies below shoulders 56 of the sensing members forming sensing member sets 46 and 48. As will be more apparent from FIG. 10, the bar 80 is supported between parallel arms 82a, b which are pivoted on shaft 42 and include cam follower portions 84a, h. The cams 78a, 78b define circular raised portions extending approximately 203, the remaining circumference of the cam being relieved. When the cam followers are contacting the raised portion of the cams, the sense release bar 80 is raised to the position shown in FIG. 3 thereby lifting the sensing members of sets 46, 48. When the cam is rotated until the relief portions are beneath the cam followers, the bar is lowered to the positions shown in FIGS. 12 and 13.
Also mounted on shaft 74 is lock release cam 86 (FIG. 9). The cam controls the movements of a pair of gates 88, 90, each defining a window 880, 90a therein. The gates are respectively pivotable about shafts 44, 42 and are joined by a cross link 92 connected above the pivot point of gate 88 and below the pivot point of gate 90. A coil spring 94 biases the gates inwardly but they are retained in a normally upright position by means of a cam follower 96 which bears against the circular portion of cam 86.
Also mounted on shaft 74 is a dead lock cam 98. This cam is provided with a radial projection 98a which, as shown in FIG. 12, engages gate 90 when rotated counterclockwise with the gate in its raised position. As shown in FIG. 13, projection 98a clears the gate when the gate is rotated inwardly.
The tape drive is controlled by a pair of conjugate cams 100a, l00b mounted on shaft 74 (FIG. 8). The cams are engaged by cam followers 1020, 102b on an escapement pawl I04 rotatably mounted on shaft 42. The opposite end of the cscapement pawl engages a four toothed ratchet 106. This ratchet, in turn, is secured to a shaft 108 controlling a toothed feed roller 110. In the illustrated embodiment, the teeth of feed roller 110 are at its ends and the tape 68 is of the type having sprocket holes along its two edges. This, however, is not a critical feature of the invention and a tape utilizing a single sprocket drive could be employed if desired. The tape 68 which passes over the feed roller is removed from a supply roll 112 (FIG. 3) rotatably mounted on a shaft 114. From the feed roller the tape passes through the spaces defined between plate 50 and support plate 70 and over an idler 116 rotatably mounted on shaft 118. From idler 116 the tape 68 passes over a torque roller assembly 150 which maintains the tape under tension in a manner to be described.
The construction of the torque roller assembly will be most apparent from a consideration of FIGS. 5 and 11. From these figures, it will be noted that a shaft 152 extends between side frames l6, l8 and is secured at its right end (as viewed in FIG. 5) to the hub 154 of a pulley 156. Pulley 156 is driven via a coil spring drive belt 158 from a drive pulley 160 mounted on shaft 74.
Rotatably mounted on shaft 152 between side frames 16, 18 is a roller 162 and end cap'164. These two elements form a take-up spool for the tape 68. The space within the roller houses a torsion spring 166 which, in its relaxed state, has an internal diameter larger than the external diameter of shaft 152. The left end 1660 of the torsion spring is secured to shaft 152 by capturing it in a diametrical slot as shown in FIG. 11. The right end l66b is engaged in a slot 168 in roller 162.
The lock 'of this invention also includes a key reset mechanism which is best illustrated in FIGS. 3 and 6. It includes a hand actuated reset bar 170 extending across the top surface of the lock and including a pair of spaced arms 170a, 17% which are pivoted to the side frames by stub shafts 172. The inner ends of the arms are bifurcated and engage pins 174a, b mounted in identical Y-shaped side members 176a, b. The pins 174a, b also extend through guide slots 178 in the side frames and additional slots 180 in the side members are guided by fixed studs 182. Extending between the side members 176a, b and across the width of the lock below the pivots 34 on the lower ends of the key stems are reset bars 184, 186. The lock of this invention is also designed to clear the keyboard automatically on completion of a cycle. For this purpose, there is mounted on the end of shaft 74, as seen in FIG. 3, a clearing cam 188. This cam has opposed high lobe portions 190, 192 terminating at radial shoulders 194, 196. A stub shaft 198 on side frame 18 rotatably supports a clearing lever 200. The lever is biased in a counterclockwise direction by means of a coil spring 202. The left end of the lever is bifurcated and engages pin 174a. At its right end the lever carries a pair of cam followers in the form of two offset ears 204, 206 which are angularly separated by an amount slightly less than the angle between shoulders 194, 196.
OPERATION The combination required to operate the lock of this invention is established by a prepunched paper tape 68. Each combination comprises two series of four digits each. Preferably, these are randomly selected by a computer which punches the tape and stores the sequence of combinations in its memory. The lock can be operated only when the proper four keys in each bank are depressed. If an improper key is depressed, or if a key is not depressed when it should be, the lock cannot be operated. The means by which this result is achieved are shown in FIGS. 12 and 13 which illustrate only the 8 key in each bank. All other keys function in an identical manner.
In order to initiate sensing, the sense release bar 80 is lowered, thereby freeing sensing members 468, 488 as well as all other sensing members. In the illustration the number "8" appears in the combination for the righthand set of keys, but not in the combination for the lefthand set of keys. FIG. 12 illustrates two improper key settings. Key 120, which should be depressed, has not been and key 140, which should not be depressed, has been. Each of these key positions establishes the vertical position of the corresponding pivot 34. However, sensing finger 52 of sensing member 468 has passed through the opening in tape 68, lowering the left end of tumbler lever 368. The right end of tumbler lever 368 is therefore positioned above the window in gate 90.
On the left side of the figure, it will be noted that, as no hole exists in the punched tape 68, sensing finger 52 is in a raised position, as is the righthand end of tumbler lever 388. This brings the lefthand end of tumbler lever 388 to a position below the window in gate 88. The gates at this point have been released, as cam 86 has been moved away from cam follower 96, and spring 94 (FIG. 9) tends to bias the gates inwardly. However, they are unable to move substantially due to the imposition of the tumbler levers. In this position, rotation of shaft 74 is stopped by virtue of deadlock cam 98 engaging the top of gate 90. As the gates are interconnected by cross link 92, only one key out of 18 needs to be improperly positioned to prevent operation of the lock.
FIG. 13 illustrates operation of the lock by proper adjustment of the keys. Here it will be noted that key 120 has been depressed, lowering pivot 34 and the righthand end of tumbler lever 368 so as to clear gate 90. Similarly, the lefthand key 140 has not been depressed, leaving the pivot point 34 raised and allowing the left end of tumbler lever 388 to clear gate 88. In this position, therefore, the gates are permitted to move inwardly as illustrated, clearing deadlock cam 98 and permitting rotation of shaft 74.
The tape control system is best described by reference to FIGS. 5, 7, 8 and 11. Drive pulley 160 on shaft 74 drives pulley 156 on shaft 152 through the action of the coil spring drive 158. As shaft 152 is not secured to the roller 162 or its end cap 164, it will wind down the torsion spring 166 against the pull of the tape until the inner diameter of the torsion spring is reduced to shaft size. Under this condition, it stores a fixed torque value. In actual practice, these elements are sized so that, with the roller fixed, approximately three turns are required to reach this condition. The torque which is delivered by the spring belt 158 must slightly exceed the stored spring torque. Thereafter, the belt 158 will slip in the pulleys. Referring now to FIG. 3, it will be noted that the torque roller assembly 150 just described will exert a pull on tape 68, keeping it under tension against the restraining force of the sprocketed feed roller 110. Movement of the tape for changing from one combination to the succeeding combination upon each actuation of the lock is provided by the escapement mechanism shown in FIG. 8. As the conjugate cams 100a, 10% are rotated, they cause the escapement pawl 104 to rock about shaft 42 in a clockwise direction. The upper lobe of the pawl releases the upper tooth of ratchet 106 causing it to rotate 45 in a clockwise direction under the tension of the tape. The 45 motion is a result of the righthand tooth of ratchet 106 contacting the lower lobe of the pawl. When the pawl then returns to the position illustrated in FIG. 8, a full 90 rotation of ratchet I06 and feed roller 110 results. The tape is punched in such a manner that the twin rows of combination-defining holes are separated by distances equal to one-fourth the circuml'ercnce of the feed roller so that they are properly aligned beneath the sensing fingers for the next operation of the lock. Each tape advance is immediately taken up by the stored torque in the roller assembly and the continuing torsional effort of the felt drive recharges the spring.
As the tape 68 accumulates on roller 162, its diameter increases, resulting in decreasing tape tension due to the fact that the torque is relatively fixed. Accordingly, the percentage of slip of the belt 158 increases proportionately. For this reason, the torque values are established to provide a suitable range of tape tension safely below the tensile strength of the tape at start up but sufiicient to assure reliable escapement function at minimum tension. These values, however, are easily ascertainable by one skilled in the art and need not be set forth in detail.
The overall operation of the lock of this invention can best be described by reference to the timing chart, FIG. 14. The
horizontal scale of this chart is one rotation of shaft 74 through 360. It will be assumed that the combination has been correctly inserted by depressing the proper four keys in each set. Knob I0 on the side ofthe lock is then turned.
As rotation begins, the shoulder 194 of clearing cam 188 passes beneath the ear 204 of clearing lever 200 (FIG. 3). This blocks manual operation of clearing bar 170 preventing the keys from being reset during the sensing portion of the cycle.
Next, cams 78a, 12 (FIG. 10) release arms 82, permitting the sense release bar 80 to drop. The eighteen sensing members then drop to a sensing position with their sensing fingers 52 either resting on the paper tape or passing through a hole therein. This causes all tumbler levers to be positioned to enter the respective windows of the movable gates as shown in FIG. 13.
Next, cam 86 releases the cam follower 96 and the gates, under the influence of spring 94, rotate inwardly, thereby clearing the deadlock cam 98 permitting continued rotation of shaft 74. After a short sensing period of less than of shaft rotation, cam 86 once more picks up cam follower 96 and retracts the gates to their initial positions.
Thereafter, at approximately 90, two cams come into action. Cams 78a, b raise the sense release bar 80, once more lifting all 18 of the sensing members. Also, high lobe portion 190 of the clearing cam 188 engages ear 206 of clearing lever 200, raising the side members 176a, b and reset bars 184, 186. The reset bars engage the lower ends of the key stems, raising all keys until they detent into their raised positions.
Thereafter, at approximately of rotation, the tape advance escapement of FIG. 8 is actuated, permitting the tape to advance and align the next combination in proper position.
Immediately after deadlock cam clears gate 90, anti-reverse means (not shown) of any suitable type may be used to prevent reverse rotation of shaft 70.
It is believed that the many advantages of this invention will now be apparent to those skilled in the art. For example, the lock is constructed primarily of stamped metal parts, many of which are duplicates. This results in a lock which is inexpensive and can be easily mass produced. Furthermore, since the combination is established by an easily changeable paper tape, all locks can be mechanically identical and still have different combinations and sequences of combinations.
It will also be apparent that a number of variations and modifications can be made in this invention without departing from its spirit and scope. The tape, for example, need not be of paper but may be of any suitable material. Furthermore, the tape may be of chadless type, defining depressions rather than holes. For this reason, the term apefture as used in the following claims is to be construed as defining such depressions and their equivalents. Also a modified construction for the gates 88 and 90 may be used as illustrated in FIG. 15 wherein the upper and lower portions of each gate window may be separated by integral horizontal bar 90'.
The lock of this invention has been described primarily as an adjunct to a postage meter. However, it will be apparent that its applications are not so limited but extend to any usage wherein its unique characteristics would be of value.
For all these reasons, the foregoing description is to be construed as illustrative only, rather than limiting. This invention is limited only by the scope of the following claims.
l. A combination lock adapted to be unlocked upon entry of the correct combination therein which comprises: an actuating member; combination determining means defining therein apertures representing elements of a preselected combination; a plurality of sensing means individually advanceable against said combination determining means and positioned to enter any aperture aligned therewith; a plurality of manual selection means, each corresponding to one of said sensing means and independently movable to represent elements of a selected combination; linkage means intermediate each of said selection means and its corresponding sensing means and adapted to assume a clearing position upon correspondence of an element of said selected combination to an element of said preselected combination and a blocking position in the absence of such correspondence; and means for normally blocking said actuating member but releasing said actuating member when all of said linkage means are in their clearing positions.
2. The lock of claim 1 wherein said combination determining means comprises a tape.
3. The lock of claim 2 wherein said tape defines therein a plurality of sets of apertures, each aperture set determining a different preselected combination.
4. The lock of claim 3 wherein said combination determining means comprises means for advancing said tape upon each actuation of said actuating member to present a different aperture set to said sensing means.
5. The lock of claim 1 wherein said combination determining means comprises: a tape defining therein a plurality of sets of apertures, each determining a different preselected combination; means for tensioning said tape for advancement relative to said sensing means; and means for normally restraining such advancement but releasing said tape for an incremental advance upon each actuation of said actuating member to present a different aperture set to said sensing means.
6. The lock of claim 5 wherein said tensioning means comprises: a shaft; means for driving said shaft uponactuation of said actuating member; a roller secured to said tape and mounted on said shaft for rotation relative thereto; and resilient means interconnecting said roller and shaft for storing a selected torque value therebetween.
7. The lock of claim 6 wherein said resilient means comprises a coil spring surrounding said shaft having its first end connected to said shaft and its second end connected to said roller, the internal diameter of said spring in its relaxed condition being greater than the outside diameter of said shaft.
8. The lock of claim 6 wherein said driving means comprises a belt and pulley drive connected to slip when said selected torque value is stored.
9. The lock of claim 1 wherein each of said manual selection means comprises a key stem longitudinally movable between a first and a second position.
10. The lock of claim 1 wherein each of said linkage means comprises a tumbler lever having first and second ends, a first pivot point therebetween, and a second pivot point at said first end, one of said pivot points being movable by said manual selection means and the other of said pivot points being movable by said sensing means.
11. The lock of claim 10 wherein each of said manual selection means comprises a key stem connected to said first pivot point of a respective tumbler lever.
12. The lock of claim 1 wherein each of said sensing means comprises: a substantially planar .member having thereon a sensing finger adapted to enter an aperture aligned therewith; and means for resiliently urging said finger into said aperture about an axis of rotation substantially perpendicular to the plane of said member and spaced from said finger.
13. The lock of claim 12 wherein said axis of rotation is common to a plurality of said members.
14. The lock of claim 12 wherein each ofsaid linkage means comprises a tumbler lever having first and second ends, a first pivot point therebetween, and a second pivot point at said first end, one of said pivot points being movable by said manual selection means and the other of said pivot points being movable by said sensing means.
15. The lock of claim 14 wherein each of said manual selection means comprises a key stem connected to said first pivot point of a respective tumbler lever.
16. The lock of claim 10 wherein said actuating member is a rotatable shaft and said blocking means comprises: a gate movable between a locking position and an actuating position, said gate being retained in said locking position by any of said tumbler levers in a blocking position but movable to said actuating position when all of said tumbler levers are in their clearing position; and a deadlock cam secured to said shaft positioned to engage said gate in its locking position to prevent rotation of said shaft and to pass said gate in its actuating position to permit rotation of said shaft.
17. The lock of claim 16 wherein each of said manual selection means comprises a key stem connected to said first pivot point of a respective tumbler lever.
18. The lock of claim 17 wherein each of said sensing means comprises: a substantially planar member having thereon a sensing finger adapted to enter an aperture aligned therewith; and means for resiliently urging said finger into said aperture about an axis of rotation substantially perpendicular to the plane of said member and spaced from said fin er.
19. A combination lock adapted to be unloc ed upon entry of the correct combination therein which comprises: a tape defining therein a plurality of sets of apertures, each determining a different preselected combination; a plurality of sensing means individually advanceable against said tape and positioned to enter any aperture aligned therewith; means for tensioning said tape for advancement relative to said sensing means; a plurality of manual selection means, each corresponding to one of said sensing means and independently movable to represent elements of a selected combination; a plurality of tumbler levers, each having first and second ends, a first pivot point therebetween, and a second pivot point at said first end, one of said pivot points being movable by one of said manual selection means and the other of said pivot points being movable by one of said sensing means, each tumbler lever assuming a clearing position upon correspondence of an element of said selected combination to an element of said preselected combination and a blocking position in the absence of such correspondence; gate means movable between a locking position and an actuating position, said gate means being retained in said locking position by any of said tumbler levers in a blocking position but movable to said actuating position when all of said tumbler levers are in their clearing positions; an actuating member normally restrained by said gate means in a locking position but movable when said gate means is in an actuating position; and means for normally restraining advancement of said tape but releasing said tape for an incremental advance upon movement of said actuating member to present a different aperture set to said sensing means.
20. The lock of claim 19 wherein each of said manual selection means comprises a key stem connected to said first pivot point of a respective tumbler lever.
21. The lock of claim 20 wherein each of said sensing means comprises: a substantially planar member connected to said second pivot point of a respective tumbler lever; a sensing finger extending from said planar member and adapted to enter an aperture aligned therewith; and means for resiliently urging said finger into said aperture about an axis of rotation substantially perpendicular to the plane of said member and spaced from said finger.
22. The lock of claim 21 wherein: each set of apertures in said tape comprises two subsets formed on spaced, parallel lines; said sensing means are arranged in two sets corresponding, respectively, to said subsets, each set being rotatable about a different axis of rotation; said key stems are arranged in two sets corresponding, respectively, to said sets of sensing means; said tumbler levers are arranged in two opposed sets with the second ends of the levers of the two sets in reversed relationship; said gate means comprise first and second planar gates disposed adjacent the respective second ends of said lever sets, each of said gates defining a window therein, said gates being biased for complementary, reversed, inward movement toward the respective lever sets, said windows being aligned to receive the second ends of those tumbler levers in a clearing position.