US3277679A

US3277679A - Snap-lock assembly

Info

Publication number: US3277679A
Application number: US503367A
Authority: US
Inventors: Albert C Sanowskis
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-23
Filing date: 1965-10-23
Publication date: 1966-10-11
Anticipated expiration: 1983-10-11

Description

Oct. 11, 1966 A. c. SANOWSKIS SNAP-LOCK ASSEMBLY 2 Sheets-Sheet 1 Filed Oct. 23, 1965 1|| Ill e "Illlllll f 45556;; iawa Oct. 11, 1966 A. c. SANOWSKIS 3,277,679

SNAP-LOCK AS SEMBLY I- T g United States Patent 3,277,679 SNAP-LOCK ASSEMBLY Albert C. Sanowskis, 7321 S. Shore Drive, Chicago, Ill. Filed Oct. 23, 1965, Ser. No. 503,367 16 Claims. (Cl. 70-313) This invention relates generally to push-button operated combination locks and more particularly, is concerned with a snap-lock assembly for use therewith.

Structures characterized as push-button operated combination locks herein are those of the type operable by a set of keys or buttons and which are provided with a lock controlling device shiftable step by step, in one direction, by operation of the keys or buttons in a predetermined sequence to release a latch engaging bolt from a latch; and which device, when the keys are not operated in sequence, will be disabled and the latch engaging bolt not released. Structures of this general character are those disclosed in my earlier United States Patents Nos. 2,665,- 57 7 and 2,75 0,786. The combination lock structure with which this invention is most closely associated is that structure disclosed and claimed in my co-pending patent application Serial No. 395,372 filed September 10, 1964.

The lock structure disclosed in my co-pending patent application utilized lock controlling means comprising a pair of flat shiftable racks or slides frictionally held in place side by side and arranged for slidable movement, each slide being provided with tines having cam surfaces at their free ends. The said cam surfaces are keyed to face in a direction so that when the keys or push-buttons are actuated, levers associated with said buttons engage the cam surfaces of the tines to shift the slides. The keying is arranged so that the cam surfaces of selected tines of one slide face in one direction and are aligned with like directed cam surfaces of the other slide whereby actuation of the levers against said aligned cam surfaces serve to move both slides conjointly and in alignment. The remaining cam surfaces of the tines of both slides are arranged so that actuation of the levers thereagainst reverse the slides or shift only one of the slides relative the other. The slides either move in a direction reversed to that desired, thereby failing to advance toward open condition or fail to move conjointly but instead, are moved relative one to the other and hence are misaligned. When the slides are misaligned, the keyed cam surfaces are also misaligned, and hence, the slides cannot further be moved conjointly and .in alignment unless and until they are realigned.

Each of the slides is provided with an opening therein to permit passage of a spring biased latch bolt control member, same functioning as latch bolt control means, So long as the slides move conjointly and aligned by manipulation of the buttons in the proper predetermined sequence, the openings in the slides also move in aligned condition. Said bolt control member is arranged so that one end bears against the slide and the other end bears against the latch bolt to prevent withdrawal thereof from the latch. After the predetermined number of stepwise movements, the openings are thus brought into alignment with the spring biased latch bolt control member so that the same passes through the aligned openings. This in turn releases the latch bolt. Ordinarily, the latch bolt is spring biased so that on release, it will snap back or withdraw into the housing. The door or like closure thus may be opened.

The co-pending patent application provided resetting means for the lock assembly to enable simultaneous withdrawal of the latch bolt control member from said aligned openings in the slides and movement of the slides to their initial condition, thereby forcing the latch bolt to extend outward from the housing. In this manner the lock was reset for reuse. However, use of the reset button was ice necessary to force the latch bolt into engaging condition with the latch. Thus when the door was closed, one had to manipulate the resetting means. Operation of the resetting means to set the latch bolt also reset the combina tion so that, to open the door, one merely performed the required manipulations of the push-buttons.

In many applications of the combination lock structures for residential and/or commercial purposes, it is desired that the residential or commercial door upon which the lock is used automatically be locked upon closing thereof instead of requiring the subsequent operation of the resetting mechanism. Further it is desired that the combination mechanism remain disabled until the door is to be opened. This would involve the provision of snaplock type structures for use in conjunction with the specific push-button operated combination lock structure. What is desired is a mechanism operative to withdraw the latch bolt controlling means from the described aligned passageways and also to set and effectively dead-bolt the latch bolt in the latch-all simultaneously with the closing of the door. Generally, available snap-lock arrangements include various forms of articulated linkages, springs, levers and the like which act to cause the latch bolt memher to be immobilized. These arrangements are not adapted for operation in conjunction with the lock structure of the character described because of the relative size and complexity of the component parts thereof, Not only are many of these arrangements unsuited because of size and complexity for use with the described combination lock structure but incorporation of such arrangements greatly increase the cost of the lock structure.

Accordingly, it is the principal object of this invention to provide an automatic resetting dead-bolt snapa lock assembly for use with a pushabutton operated combination lock of the character described, said snap-lock assembly having means for'setting of the latch bolt control means to a neutral condition on opening of the door and the dead-locking of said latch bolt upon reclosing of the door.

Another object of this invention is to provide a snap- =lock assembly of the character described for use with a push-button operated combination lock wherein the combination lock is immobilized, yet the latch bolt set in locked condition without operation of the reset means of the combination lock structure.

A further object of the invention is to provide a snaplock of the character described wherein dead-locking of the latch is effected by depression of a retractile, spring biased, rod member to compress the spring and activate a detent means, and, further to utilize the spring tension not only to release the detent means when the door is opened but, additionally to actuate a lock control mechanism for subsequent operation to unlock the lock.

Other objects and advantages of this invention will be evidenced as a preferred embodiment thereof is describe-d in detail with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a perspective view of the snap-lock according to the invention as used in conjunction with a pushbutton operated combination lock as installed on a residential and/ or commercial door.

FIG. 2 is a rear elevational view of the lock illustrated in FIG. 1.

FIG. 3 is a-perspective view of the snap-lock mechanism according to the invention in combination with selected operating elements of the push-button operated combination lock with portions deleted to show interior structure.

FIGS. 4, 5 and 6 are sectional views of the snap-lock arrangement such as illustrated in FIG. 3 so as to dia grammatically illustrate the operation of the snap-lock 3 according to the invention in its various stages of operation. 7 FIG. 7 is an end-on view of the snap-lock assembly according to the invention.

Referring to the drawings, in FIG. 1 a push-button operated combination lock structure of the character dis- I closed in my co-pending patent application to which reference has been made is designated generally by reference character 10 and is illustrated as installed on a door 12 pivotally disposed on hinges or the like (not shown) for movement in a door frame 14. The door is provided with handle 16 on opposite sides thereof to facilitate opening and closing of the door.

The combination lock structure 10 operates a snap-lock assembly according to the invention, same being generally I designated by reference character 20.

The snap-lock assembly 20 is disposed in a suitable opening 18 of the door 12 in a direction normal to the elongate body of vthe combination lock structure 10 and secured on the body by suitable slot and groove means (not shown). The snap-lock assembly 10 is provided with a retractile latch bolt 22, the end 23 of which extends outward of the door into the latch 26 contained by striker plate 28, which is secured to the door frame 14.

The operation of the push-button combination lock structure 10 is identical to that described in my pending patent application to which reference is made for details as to the construction and operation thereof. For the purposes of this description, it will sufiice to state that at least a pair of lock controlling

slides

30 and 32 are arranged in a housing 33 for conjoint slidable movement, step by step in one direction caused by selective operation of buttons or keys 34 in a predetermined sequence. Latch bolt controlling means comprising a latch bolt controlling member 36 has one end 38 bearing against a planar portion of that slide which faces the same until said end 38 is brought into alignment with a pair of aligned passageways formed in the slides so that the latch control member end 38 may be passed therethrough. The opposite end of member 36 is arranged to urge the latch engaging portion of bolt 22 exterior of the door.

The latch bolt controlling member 36 is biased so that upon placement of the passageways 40 in alignment'therewith, the member end 38 passes through said passageways. In the structure disclosed in my copending application, the latch bolt is spring biased to retractilely withdraw into its housing upon the passage of said member end 38 through the aligned passageways 40.

The combination lock structure concerned is provided with resetting means which simultaneously cause the withdrawal of the latch bolt controlling member and from the aligned passageways to reset the latch bolt and force same to extend from the housing and returns the lock controlling membersthe slidesto their initial lock set condition. In said lock set condition, all that is necessary to open the door is the proper manipulation of the buttons 34.

In the herein structure, the reset button is designated by reference character 42 and is a semi-hollow member reciprocally movable in a suitable passageway formed in the face of the plate 44 of the combination lock housing 33 and biased so that it normally extends from said housing. The reset button 42 has secured thereto a bifurcated member 46 consisting of a pair of spaced arms 47 defining a wedge-shaped slot 48 operative upon scissors .lever means 49 to reset the

slides

30, 32 in the manner described in said copending application, to their initial position for operating the lock.

The bolt withdrawal means set interior of the reset button 42 which is utilized in the structure described herein differs slightly from that described in the copending application. Here, a spring biased T-shaped member or level 50 is provided having a long arm 52 extending out- :Ward from the recess or cavity 54 of the button 42. The opposite end 56 thereof is set within one corner of said cavity 54. A helical wire spring 58 is secured between the other corner 60 and the arm 52 to insure only pivotal movement of the arm 52 around a pivot axis at 56. The short arm 53 acts as a stop to limit the reverse movement of arm 52. The latch bolt controlling member 36 includes a notched portion 62 located so that actuation of the reset button 42 in the direction indicated by arrow A, urges the free end 64 of said arm 52 against a notch 62 moving the latch bolt controlling member 36 in the direction of arrow B to withdraw the same from the aligned passageways 40 of the

racks

30 and 32.

In the assembly, according to the herein invention, the reset button 42 functions simply to cause resetting of the

slides

30 and 32 to their neutral or initial position and withdraw member end 38 from blocking contact within the passageways 40 when the

slides

30 and 32 are misaligned due to the operation of button 34 in other than the predetermined sequence and the end 38 only passes through one of the slides. Thus the purpose of the resetting button 42 in the herein invention is not simply to withdraw the latch controlling bolt member'from the aligned passageways to set the latch bolt. According to the invention, when the buttons 34 are depressed in the proper sequence and the member end 38 passes through both slides to enable opening of the door, the member end 38 is withdrawn from the passageways 40 on mere opening of the door. The mechanism by which such sequence is carried out will be described in greater detail hereinafter.

Now referring to FIG. 3, the snap-lock assembly embodying the invention is illustrated in its dead-bolted condition with the retractile latch bolt 22 extending into the latch 26 contained by striker plate 28. The bolt 22 is disposed for horizontally oriented movement in an open ended cylindrical housing 66 closed otf at its inner end 68 by a cap 70. Cap 70 has a slot 72 therein permitting the passage of the latch bolt controlling member 36 therethrough, and also includes slot and key means (not shown) for cooperation with like means (not shown) on the combination lock body 33 for securing the snap-lock assembly 20 thereto.

The latch, bolt 22 is of generally cylindrical configuration having a latch engaging end 23 integral therewith and normally disposed outward from housing 66. Said end 23 has a cam surface 76 presented to curved portion 78 of the striker plate 28. The latch engaging end 23 of bolt 22 also is provided with a fiat surface 79 which surface functions as a keeper, bearing against the edge 80 of the lat-ch when the end 23 is disposed in latch 26. Surface 79 defines with surface 82 of the bolt 22, a shoulder indicated by reference character 84. A retainer plate 24 is provided with opening 86 of semi-cylindrical crosssectional configuration so as to permit passageof the latch engaging end 23'of bolt 22 therethrough, but to retain the remainder of bolt 22 in the housing by providing a retainer surface 88 adapted to have shoulder 84 seated thereagainst. A pair of small diameter, closed end bores 90 are provided in said bolt 22 opening to surface 82, and a pair of like helical springs 92 are seated therein. An axial, closed end bore 94 is formed in said bolt 22 opening to the rear surface 82' thereof and a helical spring '96 is accommodated seated therein. Spring 96 is chosen to be stronger than the pair of springs 92 for a purpose to be described.

An elongate groove 98 of substantially semi-cylindrical, cross-section is formed in the annular surface 102 of A latch bolt 22. Groove 98 is disposed between the pair of bores 90 and opening radially to said surface 102. An elongate, hollow, retractile rod 104, preferably of cylindrical cross-sectional configuration is disposed for reciprocal movement within groove 98. Said hollow rod 104 has an inner open end 106 and a closed end 107 which extends outward of the housing 66 through suitable opening 108 formed in plate 24. A helical spring 110 is seated within the hollow portion 112 of rod 104 and bears against the closed end 107. The opposite end of spring 110 is seated against surface 114 of cap 70.

A disc 116 is disposed within housing 66 between the end cap 70 and the inner end surface 82' of latch bolt 22. Rod 104 is secured at its open end 106 to disc 116 with the spring 110 passing through opening 106 formed in the disc 116. The disc 116 also has a central passageway 118 of a configuration to accommodate, loosely, the latch bolt controlling member 36 for movement therethrough. Disc 116, of course, is movable reciprocally in the housing, carried by movement of rod 104. Latch bolt controlling member 136 is provided with a plate or seat 120 secured thereto adjacent end 122 thereof. Seat 120 is of a dimension so as to be capable of passage into bore 94. Passageway or slot 118 in disc 116 is of non-conforming configuration to that of seat 120 so that said seat cannot pass through slot 118. In the embodiment described seat 120 is of circular configuration while slot 118 is of rectangular configuration. The maximum diameter of seat 120 is chosen so as to be slightly less than the diameter of bore 94 so that seat 120 can pass freely therewithin. The diameter of the spring 96 is chosen so that one end 124 is seated on seat 120 with said spring being within bore 94. A wire spring 128 is secured to member 36 at notch 130 formed in said latch bolt controlling member. Wire spring 128 has an elongate portion 132 arranged disposed outwardly inclined along member 36 toward the end 122 thereof. The elongate portion 132 has a bent terminal portion 134 integral therewith and extending toward the member 36. End 122 of member 36 is provided with a transverse passageway 136 formed therein closely adjacent the seat 120 to accommodate terminal portion 134 of spring 128 when portion 132 thereof is disposed fiat against the member 36. Under such conditions, both spring 128 and seat 120 can enter bore 94. The angle of inclination of portion 134 of wire spring 128 relative to member 36 is chosen so that said terminal portion 134 normally extends outward of passageway 136 and bears against surface 82' unless restrained by the disc 116. Thus, the terminal portion 134 functions as detent means to prevent movement of the latch bolt 22 when the disc 116 is spaced from the end surface 82' of said latch bolt 22. Such condition exists when the member 104 is retracted interior of the housing 66 and the latch bolt 22 extends outward from the housing 66.

Attention is now directed to the operation of the automatic resetting deadbolt, snap-lock assembly 10. In the view shown in FIG. 3, the assembly is shown in a deadlock position With latch bolt 22 extending into the latch 26 surrounded or contained by striker plate 28. The hollow rod 104 is retracted into the housing 66 and retained against the bias of spring 110 by striker plate 28. Spring 110 is in compressed condition. Member 36 is threaded through slot 118 but disc 116 is spaced from the rear surface 82' of bolt 22. Spring 128 is shown inclined away from member 36 with terminal portion 34 hearing against surface 82'. Springs 92 are compressed while spring 96 is in normal extended condition. The reset button 42 has not been depressed, but the slide 30 has its planar surface bearing against end 38 of member 36.

In FIG. 4, the door 12 is fully open subsequent to the correct manipulation of buttons 34. Spring 110' has expanded to force member 104 from the housing 66 since rod 104 is no longer restrained by portion 78 of strike plate 28. The disc 116 is carried by movement of mem her 104 and forces the latch engaging end 23 of bolt 22 from the housing 66. Springs 92 seated in openings 90 in bolt 22 are compressed and are restrained by the inner surface 108 of plate 124 as shown at 142. Movement of disc 116 has forced the spring 128 against member 36 with terminal portion 134 accommodated entirely Within passageway 136 of member 36 so that the seat 120 and spring 128 can enter passageway 94 to compress spring 96. The movement of disc 116 also carries with it the seat 120 of member 36 withdrawing end 38 from the

slides

30 and 32. Gravity then causes the slides to descent since there is no longer friction exercised to maintain the position thereof. Now the end 38 is spaced slightly from the planar surface of facing slide 30'.

When the door 12 is closed, portion 78 of striker plate 28 will contact the cam surface 76 of latch engaging end 23 of bolt 22 to cause same to retract into the housing 66. Simultaneously disc 116 is carried inward of the housing 66. The rod 104 is thus retracted into housing 66 to compress spring 110. Now .the assembly assumes the condition shown in FIG. 6. Since the latch bolt controlling member 36 cannot move because the

racks

30 and 32 prevent such movement and because seat 120 and spring 128 can move through passageway 118 into bore 94, the retraction of latch bolt 22 compresses spring 96 as shown in FIG. 6'. As the bolt 22 clears the surface 78 and is aligned with the latch opening contained by plate 28, the spring 96, being stronger than springs 92, will leave its compressed condition forcing the latch bolt end 23 outward from the housing into the latch to assume a position as shown in FIG. 5. The strike plate surface 78 restrains the movement of rod 104 so that the same is not permitted to move exterior of the housing and spring remains compressed.

At the same time that bolt 22 moves away from the disc 116, the spring 128 is no longer held against bolt 36 by the disc 116 and so terminal portion 134 moves out of passageway 136 so as to prevent the latch bolt 22 from retracting interior of housing 66. Thus the bolt is dead-locked as shown in FIGS. 3 and 5.

Once the

slides

30 and 32 are reset and move stepwise conjointly by proper manipulation in the predetermined sequence of buttons 34 so that openings 40 are brought into position to enable end 38 of member 36 to pass therethrough, the latch bolt 22 then will be forced, by expansion of springs 92, to retract into housing 66. Thus the latch bolt 22 moves against disc 116 so as to clear the latch. By such movement of member 36, the spring 128 is again urged against member 36 as it travels through passage 118. Now the door can be opened simply by grasping and pulling upon handle 16.

As the door opens, and the rod 104 clears the strike plate 28, spring 110 expands and urges the rod 104 outward, simultaneously moving the member 36 and moving the end 38 thereof away from the

slides

30 and 32. Since the slides, as stated, normally are held in place by the friction caused by the bearing of end 38 thereagainst as described in my copending application, when the friction is removed, the slides drop due to gravity so that the passageways 40 are no longer aligned with end 38. Now the assembly 10 assumes a condition illustrated in FIG. 4. Therefore when the door is pushed closed in the manner described above, the lock already is placed in substantially set condition.

The combination lock can only be operated with the door closed because so long as the door is ajar, there is no friction holding the slides in place. In order to open the lock when the door is closed, reset button 42 is depressed in the direction indicated by arrow A. The

slides are returned to normal or initial neutral position by the camlike edges of .slot 48 exercised against the scissors lever means (not shown). Reference is made to my copending application for detailed explanation of this mechanism. Thus the reset button 42 need only be actutted for opening of the door while, once closed, the door is locked, the latch bolt 22 being deadlocked relative the latch.

It should be understood that variations and modifications can be made to lock assembly 20 without departing from the concept of the invention. For example, spring 128 may be replaced by an end pivoted lever secured within an elongate slot formed in member 36. Spring end 124 then would be provided with a tail or extension which acts to bias the lever normally from the said slot to 7 block the retraction of bolt 28. Another modification may be made independently of that last described. Here, the rod 104 may be formed as a solid member with spring 110 enlarged in diameter but reduced in length so as to bear against disc 116 between said disc and cap '70.

It is believed that the invention has been described in sulficient detail to enable the skilled artisan to practice the same. Other variations than those above described may occur to the skilled artisan without departing from the spirit and scope of the invention as defined in the claims.

What I claim is: 4

1. In combination, a push button operated combination lock having a plurality of push buttons requiring the consecutive depression of a chosen sequence of said push buttons to effect the change of said lock from an initial locked condition to an open condition, and including a lock controlling device coupled to said buttons and shiftable stepby step in one direction to pass latch bolt control means therethrough to release the latch bolt but only upon depression of the proper sequence of said chosen buttons and wherein depression of said push buttons in other but the predetermined sequence serves to disable a lock controlling device, means for resetting the lock controlling device to the initial locked condition, which means includes scissors lever means operable on the lock controlling device, withdrawal means cooperable simultaneously with said scissors lever means to release said lock controlling device for resetting and actuating means to operate simultaneously both the scissors lever means and the withdrawal means, and, an automatic snap-lock assembly comprising -a hollow housing adapted to be secured to said combination lock, one end of the housing adapted to have the latch bolt disposed therein with a portion thereof normally biased exterior thereof, said latch bolt control means extending within said housing, detent means carried by said latch bolt control means and operable to prevent retraction of said latch bolt, detent control means operable to render the said detent means normally inefiective when the door is open, plural spring means disposed in .the housing and operable normally to bias both the latch bolt and the detent control means exterior of the housing, and means operable to first retract both detent control means and latch bolt during the closing of the door and thereafter to permit release of the latch bolt while retaining the detent control means retracted interior of the housing to render the detent means effective whereby to prevent retraction of the latch bolt so long as the door is closed and until the operation of said push button in the predetermined sequence.

2. The combination as claimed in claim 1 in which said latch bolt has a cavity opening to the housing and said plural spring means comprises a. first spring means disposed in said cavity and seated upon the latch bolt controlling means, and said latch bolt has a second cavity opening to the exterior of the housing and a second spring means seated therein to bias the latch bolt in retracted condition and stop means to contain said second spring means within the housing, said first spring means being stronger than the second spring means.

3. The combination as claimed in claim 1 wherein said detent means comprises an elongate member secured at one end thereof to said latch bolt controlling means and biased to be normally disposed with the opposite end thereof blocking retraction of said latch bolt.

4. The combination as claimed in claim 3 in which said detent control means comprises a spring biased rod disposed for reciprocation within said housing and normally biased exterior thereof and a disc disposed within said housing and secured to the inner end of said rod and having a passageway of configuration to accommodate said latch bolt controlling means therethrough and movable with said rod between two conditions, the first being adjacent the inner end of said latch bolt and the second being spaced from the inner end of said latch bolt,

said detent means being in effective condition when the disc is in its second condition.

5. The combination as claimed in claim 3 in which said elongate member is a spring.

6. An automatic dead-bolt snap-lock assembly for use with a push button operated combination lock which includes latch bolt control means normally urging a spn'ngbiased retractile latch bolt exterior of a housing to engage within a latch and said latch bolt control means operable, upon manipulation of a plurality of push-buttons in a predetermined sequence of operation, to release the latch bolt whereupon the same retracts into the said housing; said snap-lock assembly comprising a hollow open-end housing, a cap closing off one end of the housing, said cap having slot means therein for accommodating said latch bolt control means therethrough and means for securing said housing to said combination lock, a spring biased retractile latch bolt arranged for linear movement within the housing and having a latch engaging end normally protruding from the housing, detent means for preventing retractile movement of the latch bolt interior of the housing, detent control means disposed within the housing between the latch bolt and the cap, said detent control means operating to place the detent means in its effective condition when the door is closed and to release said detent means when the door is opened, and plural spring means of differing strength selectively to bias both latch bolt and detent control means exterior of the housing when the door is open, to bias only the :latch bolt exterior of the housing when the door is closed and to retractthe latch bolt interior or the housing on release of the latch bolt control means upon completion of proper manipulation of the push buttom.

7. The structure as claimed in claim'6 wherein said detent means comprises an elongate member secured to said latch bolt control means and having a position thereof arranged normally biased to block retraction of the latch bolt and said detent control means comprises an elongate element, a disc secured at one end of said element, the other end of said element biased normally extending from the housing and said disc carrying means to operate on said elongate member to disengage said portion thereof from blocking position relative to said latch bolt when said elongate element is in extended position.

8. The structure as claimed in claim 7 in which said elongated element is a hollow rod closed off at one end and secured to said disc at the opposite end thereof, said third spring means being disposed within said hollow tube.

9. The structure as claimed in claim 7 and means for retaining the tube in retracted condition while permitting the latch-engaging end of the latch bolt to extend from the housing when the door is closed.

10. The structure as claimed in claim 7, the said disc has a passageway to permit reciprocal movement of said latch bolt control means therethrough but also to retain said latch bolt control means within the housing, said latch bolt control means having an end formation of non-conforming configuration relative the said passageway. a

11. A self-setting snap-lock assembly for a door and the like comprising:

(i) a latch bolt housing open at one end thereof;

(ii) a retr actile latch bolt mounted in said housing for rectilinear sliding movement and having a latch engaging portion movable through said open end of said housing;

(iii) a releasable latch-bolt control means operable between two conditions, the first with the latch engaging end of the latch bolt biased exterior of the housing and the second, with the said latch engaging end retracted within the housing;

(iv) detent means mounted on said latch-bolt control means for preventing retractile movement of said latch engaging end during the aforesaid first condition;

(v) detent control means operable to render the detent effective when the door is closed and to release the etent upon opening of the door;

(vi) first spring biasing means disposed between the latch bolt control means and the latch bolt, normally to bias the latch engaging end of the latch bolt exterior of the housing, second spring biasing means between the interior of the housing and the detent control means and operative on said detent control means normally to bias said detent control means in position to release the detent means, and third spring biasing means disposed interior of the housing and operative on said latch bolt normally to bias said latch bolt interior of the housing, said first spring biasing means being stronger than said third spring biasing means whereby to overcome same upon closing of the door and said third spring biasing means operative to retract said latch bolt when said latch-bolt control means assumes the second condition thereof, said third spring biasing means being in compressed condition when the door is closed.

12. A snap-lock assembly for a door and the like comprising: a latch bolt housing open at one end, a retractile latch bolt slidably mounted in said housing and having a latch engaging end movable rectilinearly into and out of said housing through the open end thereof, detent means arranged within said housing and operable between an active and a passive condition respectively to block and to permit retractile movement of said latch bolt end, a retractile member slidably mounted in said housing adjacent to said latch engaging end and movable rectilinearly, independent of movement of said latch engaging end, into and out of said housing through the open end thereof along a path of movement parallel to the path of movement of said latch engaging end, detent control means arranged within said housing and coupled to said retractile member spring biasing means arranged within said housing normally to bias both latch engaging end and retractile member exterior of the housing, said retractile member capable of being depressed against its normal bias to retract same interior of said housing upon closing of the door, means to maintain said retractile member in retracted condition while the door is closed although said latch engaging end is disposed exterior of the housing thereby to space the detent control means from said latch engaging end and activate said detent means, a lock control mechanism selectively operable to release the normal spring bias operative upon said latch engaging end :to permit retraction of same interior of the housing and, simultaneously to cause the detent means to retract further interior of said housing along with retraction of said latch engaging end, said detent control means operable to deactivate said detent means during said last mentioned movement thereof, and, said retractile member being released from the housing upon opening of the door simultaneously to reset said lock control mechanism to its preoperated condition.

13. The structure as claimed in claim 12 in which said detent control means comprises a plate secured to the inner end of said retractile member, and movable therewith, said plate being reciprocable between a first posi tion adjacent to the latch engaging end and a second position spaced from said latch engaging end and said detent means being in active condition in said second position and caused to assume passive condition in said first position.

14. The structure as claimed in claim 12 in which said plate has a passage formed therein and said detent means is arranged through said passage.

15. The structure as claimed in claim 14 in which said detent means comprises a wire having an end portion arranged norm-ally to block retraction of said latch engaging end but movable upon release of said lock control mechanism through said passage in said plate which movement causes said portion to assume a non-blocking position.

16. A pushbutton operated combination lock for a door and the like which comprises a plurality of pushbuttons adapted to be depressed in accordance with a pre-selected program, rcc-tilinearly movable lock controlling means driven by said buttons and having recesses adapted to align only when the pre-selected program has been followed, latch bolt controlling means normally held in a first position when the recesses are not aligned but movable to a second position when the recesses are aligned, and an automatic snap lock assembly comprising a hollow housing adapted to be coupled to said combination lock, one end of the housing adapted to have the latch bolt disposed therein with a portion thereof normally biased exterior thereof, said latch bolt controlling means extending interior of said housing, detent means carried by said latch bolt controlling means and operable to prevent retraction of said latch bolt, detent control means operable to render the said detent means normally ineffective when the door is open, plural spring means disposed in the housing and operable normally to bias both said portion of the latch bolt and the detent means exterior of the housing, and means operable to first retract both detent control means and latch bolt during the closing of the door and thereafter permit release of the latch bolt portion while retaining the detent means effective whereby to prevent retraction of the latch bolt so long as the door is closed and until the operation of said push buttons in accordance with said pre-selected program.

References Cited by the Examiner UNITED STATES PATENTS 1,185,468 5/1916 Borg -313 2,029,080 1/1936 Mills 70-313 2,346,513 4/ 1944 Sidel-inker 703 13 2,750,786 6/ 1956 Sanowskis 70-3 13 BOBBY R. GAY, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIQN Patent No, 3,277,679 October 11, 1966 Albert C, Sanowskis It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 73, for "level" ead L lever column 6, line 65, for "actutted" read w actuated column 8, line 38, for "position" read portion line 49, for "elongated" read elongate Signed and sealed this 22nd day of August 1967,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Offieer Commissioner of Patents

Claims

1. IN COMBINATION, A PUSH BUTTON OPERATED COMBINATION LOCK HAVING A PLURALITY OF PUSH BUTTONS REQUIRING THE CONSECUTIVE DEPRESSION OF A CHOSEN SEQUENCE OF SAID PUSH BUTTONS TO EFFECT THE CHANGE OF SAID LOCK FROM AN INITIAL LOCKED CONDITION TO AN OPEN CONDITION, AND INCLUDING A LOCK CONTROLLING DEVICE COUPLED TO SAID BUTTONS AND SHIFTABLE STEP BY STEP IN ONE DIRECTION TO PASS LATCH BOLT CONTROL MEANS THERETHROUGH TO RELEASE THE LATCH BOLT BUT ONLY UPON DEPRESSION OF THE PROPER SEQUENCE OF SAID CHOSEN BUTTONS AND WHEREIN DEPRESSION OF SAID PUSH BUTTONS IN OTHER BUT THE PREDETERMINED SEQUENCE SERVES TO DISABLE A LOCK CONTROLLING DEVICE, MEANS FOR RESETTING THE LOCK CONTROLLING DEVICE TO THE INITIAL LOCKED CONDITION, WHICH MEANS INCLUDES SCISSORS LEVER MEANS OPERABLE ON THE LOCK CONTROLLING DEVICE, WITHDRAWAL MEANS COOPERABLE SIMULTANEOUSLY WITH SAID SCISSORS LEVER MEANS TO RELEASE SAID LOCK CONTROLLING DEVICE FOR RESETTING AND ACTUATING MEANS TO OPERATE SIMULTANEOUSLY BOTH THE SCISSORS LEVER MEANS AND THE WITHDRAWAL MEANS, AND, AN AUTOMATIC SNAP-LOCK ASSEMBLY COMPRISING A HOLLOW HOUSING ADAPTED TO BE SECURED TO SAID COMBINATION LOCK, ONE END OF THE HOUSING ADAPTED TO HAVE THE LATCH BOLT DISPOSED THEREIN WITH A PORTION THEREOF NORMALLY BIASED EXTERIOR THEREOF, SAID LATCH BOLT CONTROL MEANS EXTENDING WITHIN SAID HOUS-