United States Patent 3808984

A pair of interrelated lock cylinders mounted in spaced parallel relationship preferably through separate cylinder apertures in a removable closure or door. The door is adapted for accommodation within an access opening of a security box or other enclosure which has marginal recessed portions for receiving the peripheral edges of the door. Each of the lock cylinders is provided, on one side of the door, with a mating gear adapted for meshed engagement to effectuate interdependent cylinder operation. The insertion of a key into a key slot in each of the respective cylinders and the simultaneous turning of both keys is required in order to rotationally displace a tongue latch, integral with one of the mating gears, into selective locking engagement behind a latch keeper, whereby the door is secured in the access opening. Additionally, a tongue latch guard prevents the latch from being deformed by an external force, or otherwise misaligned, and thereby protects against unauthorized disengagement of the latch. An alternate arrangement of the lock mechanism is adapted for incorporation in a rim or mortise type lock.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
International Classes:
E05B35/12; (IPC1-7): E06B5/10
Field of Search:
109/58,59,61,62,64,66,73,50 70
View Patent Images:
US Patent References:
3715998WALL SAFE1973-02-13Teleky
3261188Quick-change axial pin tumbler lock assembly1966-07-19Kerr
3176487Externally mounted lock1965-04-06Davenbaugh
2163121Door lock1939-06-20Holtzman
1850639Chest door and chest structure1932-03-22Sioberg

Foreign References:
Primary Examiner:
Stein, Mervin
Assistant Examiner:
Kannan, Philip C.
Attorney, Agent or Firm:
Natter & Natter
Parent Case Data:


This is a Continuation-In-Part of a co-pending application by the same inventor, Ser. No. 154,362 filed June 18, 1971, now U.S. Pat. No. 3,715,998 and includes subject matter not disclosed in that prior application.
1. In a coinbox including a container for the collection of money deposited therein, the container having an access opening for removal of said money, a frame member around the inside perimeter of the access opening having recessed portions along a top and bottom margin of the opening and along two opposed sides of the opening, a removable closure member having depending flange portions along two opposed edges thereof, the closure member being adapted for selective engagement within the access opening by insertion of a first end of the closure member into a recessed portion along one of said margins with the plane of the closure member at any angle to the plane of the opening and being swingable toward the opening to permit the flange portions to penetrate the recessed portions along the two opposed sides of the opening, the closure member then being slidable to seat a second end of the closure member in the recessed portion along the other of said margins, and improved locking means for the closure member comprising plural lock cylinders separably mounted transversely through the closure member in spaced parallel relationship, a gear member attached to each of said cylinders with one of said gear members being directly engageable by the other of said gear members for mutually dependent cylinder operation, latch means for securing the closure member, including an extension along a portion of the circumference of one of the gear members, said extension being rotationally displaceable during engagement with the other of said gear members, and further including retaining means fixedly positioned with respect to the cylinders and engageable by the extension for securing the closure member in a locked

2. A device as claimed in claim 1 wherein the retaining means includes a latch keeper formed integrally with the frame member, said latch keeper being disposed in confronting relationship with the latch means when the

3. A device as claimed in claim 2 wherein the latch keeper includes a bearing surface disposed substantially normal to the plane of the access opening and engageable by the latch means for seating the closure member and further includes a support leg disposed substantially parallel to the plane of the access opening for structurally reinforcing the bearing

4. A device as claimed in claim 3 further including a tongue latch guard mounted within the access opening interiorly of the latch keeper, said latch means being disposed between the latch keeper and tongue latch guard

5. A device as claimed in claim 1 wherein each gear member has external gear teeth and at least one of said gear members has a discontinuity of teeth coincident with the extension along a portion of its circumference

6. A device as claimed in claim 5 wherein the tongue latch is unitary with the gear and projects radially and substantially in a plane parallel to the plane of the gear.


1. Field of the Invention

The invention relates generally to a security device and especially to a lock mechanism suitable for use with a security box or other enclosure, such as a wall safe, strongbox, coinbox, or similar container, and particularly those receptacles used for the deposit, collection and/or temporary storage of jewelry, money and other valuable property. In particular the lock mechanism of this invention employs a multiple cylinder arrangement for mutually dependent key operation.

2. Description of the Prior Art

Many of the prior security devices employ hinged doors and thus are vulnerable to attack through the exposed hinges; other types are subject to forceable entry by the insertion of a tool under an externally exposed edge of the door for prying same open. It has also been found that the lock cylinders in such doors are readily subject to tampering, and it is commonly known that the insertion of a sharp instrument or pick can open most locks. This situation presents serious security problems especially in regard to easily accessible coinboxes, such as those found in vending machines, parking meters, public telephones and automatic clothes washing and/or drying machines. Because of the large number and diverse location of these receptacles, it is not economically feasible to maintain a close surveillance, yet some effective safeguard is urgently needed to prevent unauthorized persons from breaking into the coinboxes.

In an attempt to alleviate the shortcomings of the prior art, the security device of this invention provides a relatively pick-proof cylinder arrangement for a lock mechanism suitable for incorporation in a closure, such as a door. The door preferably has no hinged connections and is bodily removable and adapted for recessed accommodation within an access opening of a security box or other enclosure. The lock mechanism greatly increases the difficulty, if not making it totally impossible for one to pick the cylinders. Furthermore, the additional time required in even attempting to open more than one cylinder, would be a deterrent, especially if the coinbox is situated in a location where such delay may subject the activities to detection.

Prior art locks employing multiple keys generally are of the master or guard key and customer type and frequently employ a customer key shutout. In a typical lock device, a deadlock dog must first be moved or released by employment of a guard key; a customer key is then used to activate the operating mechanism. These lock devices having multiple key cylinders do not require the simultaneous cooperation of the cylinders, as is necessary in the present invention. Another lock mechanism as shown in U.S. Pat. No. 2,163,121 has a meshed gear arrangement with an intermediary gear and a double cylinder held in twin relation and mounted through a single lock opening. The instant invention utilizes separate interdependent cylinders with gears in direct meshing engagement including an integral tongue latch and provides a much simpler, less expensive and more compact construction.


The security device of the instant invention encompasses a closure member and lock arrangement for use therewith. The closure member includes a generally planar removable door adapted to be selectively received and lockingly engaged within an access opening defined in a security enclosure, such as a coinbox. An internally mounted frame member surrounding the opening provides a recess or groove along the perimeter or boundary of the opening for accommodating the peripheral edges of the door member. Two opposed edges of the door are formed with dependent flange portions which are slidably received in corresponding portions of the recess for positionally adjusting the door in locking engagement and for permitting removal of the door.

The lock arrangement employs multiple interdependent cylinders separably mounted in juxtaposition through cylinder openings as in the door member. Each of the cylinders houses a rotatably key plug having a key slot and a rearwardly extending integral shank portion. The maximum rotational displacement of the key plug is limited by a cam member rotatable with the key plug and into contact with a stop member. Mating gears having external gear teeth, are secured to the shank portion of the respective cylinders for meshing engagement which is effective only during simultaneous rotation of both key plugs. One of the gears has a radial extension along its outer circumference which forms a tongue latch. The tongue latch is adapted to be rotationally displaced behind a latch keeper to secure the door in locked engagement. The latch keeper is formed integrally with the frame member and is reinforced for added strength. The lock cylinders can alternatively be used in other lock mechanisms, and can for example be employed to extend or retract a lock bolt such as in a rim or mortise lock.

Since the key plugs can only be rotated when respective keys are inserted into the key slots in each of the key plugs, a feature of this invention is that the tongue latch is rotatable into a locked or unlocked mode only when both key plugs are released for rotation by respective keys. This provides a relatively pick resistant lock mechanism. Additionally, a tongue latch guard extending from the frame member will prevent the tongue latch from being deformed, misaligned or otherwise distorted as by the application of an outside force to thus avoid the latch keeper. Furthermore, as previously discussed the appearance of multiple lock cylinders serves as a deterrent to potential burglars.

Another feature of the invention to thwart or otherwise discourage forceable entry such as by prying open the door, relates to the cooperation of the door and the security enclosure, wherein a unitary frame is internally mounted adjacent the access opening of the enclosure and provides a recess for accomodation of the peripheral edges of the door. When the door is positioned within the opening, the edges formed with depending flange portions are received in a portion of the recess; the other two opposed edges of the door are also received in other portions of the recess and are overlapped by a lip surrounding the opening; the door is thus highly resistant to unauthorized forceable removal.

A further feature of the invention involves the fact that this lock mechanism can be incorporated with an existing system having a single lock cylinder by providing another cylinder in juxtaposition and by gearing the two for interdependent operation.

An object therefore of this invention is to provide a security device of the general character described herein.

It is another object of the present invention to provide a relative pick-resistant lock mechanism having dual cylinders geared for mutually dependent operation.

Specifically, it is an object of the instant invention to provide a security device having a removable door adapted for overlapped recessed accommodation within an access opening of a security enclosure and including a lock mechanism having key operated multiple cylinders.

It is a further object of the invention to provide in a lock mechanism interdependent operation of two juxtaposed cylinders including mating gears adapted for meshed engagement during simultaneous rotation of both cylinders.

Another object of the invention is to provide in a lock mechanism, locking means including an integral tongue latch extending from one of the gears and adapted for selective rotation into engagement with a latch keeper.

The above and other objects, features and advantages of the present invention will be apparent from the following description of the preferred embodiments when considered in connection with the accompanying drawings.


FIG. 1 is a perspective view of a coin operated commercial clothes washing machine illustrating a typical application of the security device of this invention;

FIG. 2 is an enlarged fragmentary view of a coinbox attached to the washing machine, with a removable door including a multiple cylinder lock mechanism, a portion of the door is cut away to expose an internal frame member;

FIG. 3 is an enlarged sectional view taken along line 3--3 of FIG. 2 showing a section through the internal frame member and a wall of the enclosure, including a recess for accommodating a flange portion of the door;

FIG. 4 is a reduced size perspective view of the door as viewed from the rear with the lock cylinders removed and shows the two opposed dependent flange portions and a locking catch;

FIG. 5 is an enlarged sectional view taken substantially along line 5--5 of FIG. 2 and shows the door member lockingly engaged within an access opening of the enclosure and also illustrates, by phantom lines, the positioning of the door as it is rotated into and out of the opening;

FIG. 6 is an auxiliary view taken substantially along line 6--6 of FIG. 5 and shows the meshed engagement of the mating gears on the respective cylinders and the integral tongue latch, the arrows indicate the direction of rotational movement of the gears;

FIG. 7 is an enlarged fragmentary perspective view showing in exploded fashion, a lock cylinder with a rotational stop number, and two mating gears, one of which has an integral tongue latch; and

FIG. 8 is a sectional view of a modified embodiment wherein the multiple lock cylinder mechanism of this invention is shown as incorporated in a rim lock mounted through the face of a door.


Referring now in detail to the drawings, the reference numeral 10 refers generally to the security device of this invention. In particular, the application illustrated in this preferred embodiment shows the security device 10 used in conjunction with a commercial clothes washing machine 12 having a receptacle or coinbox 14 for receiving money deposited in a slot or slide 15, which activates the operating mechanism of the machine in a conventional manner. It should however be pointed out that the security device can be utilized in other applications, as for example, in wall safes such as those suitable for installation in hotels or motels, in parking meters, in public telephones, in money strongboxes, e.g. for securing fares in taxicabs or buses, and for like purposes.

A preferred embodiment of the security device includes the coinbox 14, shown as having a generally rectangular configuration, and preferably fabricated of heavy gauge steel with welded seams, although other material providing sufficient structural strength may be substituted. An access opening 16 is located in one of the sides of the coinbox 14, and is adapted to accommodate an independent or removable closure member or door 18. The door 18 is preferably fabricated of stainless steel for durability and may be provided with a tray (not shown) affixed to a rear face and into which coins deposited in the coinbox 14 can be collected.

An integral frame member 20 is affixed around the inside perimeter of the access opening 16, and for example, may be attached by welding to the coinbox 14. The frame member 20 is designed to retain the door member 18 in a locked position and for that purpose is shaped or formed to provide corresponding recesses or grooves 22, 22' along two sides of the access opening 16. Two opposed edges of the door form depending flange portions 24, 26 adapted to be slidingly received within the recesses 22, 22'. A top and bottom edge 28, 30 of the door 18 is received respectively in corresponding recesses 23, 23' formed by the frame member 20 along a top 32 and a bottom 34 margin of the access opening 16. The recesses 23, 23' are formed so as to permit the insertion of the door 18 along the top margin 32, while the plane of the door 18 is at a substantial angle to the plane of the opening 16; the door 18 may be then rotated into a vertical disposition so that the flange portions 24, 26 penetrate into the recesses 22, 22'. The door 18 may be slidingly moved downwardly until a locking catch 36, which as illustrated is in the shape of a Z-bar, and can be welded to the rear face of the door 18, comes into contact with the frame member 20 at the bottom margin 34. When the door 18 is in this position, a lip 38, 40 at the top and bottom margins 32, 34 overlaps the door 18.

The door 18 is secured in place by a lock mechanism including two interdependent cylinders 42, 44. In the embodiment illustrated, a lock cylinder such as that sold under the trademark "Ace" and manufactured by the Chicago Lock Company, can be employed and as shown, has a circular keyway or slot 46, 48. However, other conventional lock cylinders may be equally as effective and may be substituted for those shown. The cylinders 42, 44 are mounted to the door 18 through respective cylinder apertures 47, 48 and are secured in place by means of a lock nut 50, 52. It should at this point be mentioned that one of the two cylinders 42, 44 may have been an existing cylinder previously installed for conventional use and may thus be modified by the addition of a second cylinder mechanically linked for interdependent operation in a manner as will be described with respect to the preferred embodiment.

Referring to FIGS. 5, 6 and 7, the cylinder 42 has a rotatable key plug 54, key slot 46 and tumbler arrangement (not shown) as is conventional in the art. Additionally, a rearwardly extending integral shank portion 58 is keyed to accept a cam member 60 which will rotate with the shank 58. However, the rotation of the shank 58 is limited by interference of the cam 60 with a shoulder or stop 62. A gear 64, having external gear teeth around its circumference, is secured for rotation to the shank 58 by lock washer and nut 66. In a similar manner, a gear 70 having external teeth along a portion of its circumference and a cam 68 are secured to cylinder 44.

It should be noted that the cam members 60, 68 are positioned in the complementary fashion so as to permit respective clockwise and counterclockwise meshing engagement during rotation of gears 64, 70, as illustrated in FIG. 6. The rotational displacement is limited to approximately 90° and will be sufficient to rotate a tongue latch 72 integral with the gear 70 into and out of engagement with a latch keeper 74. The latch keeper 74 is formed as an integral part of the frame member 20 and has a bearing surface 76, and a support leg 78 for structurally reinforcing the keeper 74. Additionally, a latch guard 80 adjacent the latch keeper 74 extends to a position behind the tongue latch 72 when in the locked mode.

The tongue latch 72 is formed integrally with the gear 70 and extends downwardly and radially outwardly for alignment between the latch keeper 74 and the latch guard 80 as best shown in FIG. 5. The arrows in FIG. 6 indicate the direction of the rotation of the gears 64, 70, and the displacement of the tongue latch 72; the broken line arrows indicate the direction of rotation of the gears 64, 70 when the tongue latch is rotated to the unlocked position, and the solid line arrows indicate movement to the locked mode.

The tongue latch 72 additionally serves to seat the door 18 and locking catch 36 by exerting a downward force on the bearing surface 76, as the latch 72 is rotated into the locked mode, which in turn causes the door 18 to slide into the locked position shown in FIG. 5. The support leg 78 provides rigidity to the keeper 74 and particularly to the bearing surface 76. This will also defeat an attempt to remove the door 18 by hammering the exposed portion of the cylinders 42 44 or by otherwise forceably sliding the door 18 upward toward the keeper 74 so that the tongue latch 72 could exert enough pressure to bend or deform the bearing surface 76 a distance sufficient to provide the necessary clearance to remove the door without operating the lock cylinders 42, 44.

The latch guard 80 serves to prevent the tongue latch 72 from being deformed, misaligned or otherwise distorted so as to avoid the latch keeper 74. For example, a burglar may attempt to pierce the door 18 with a drill punch or by drilling a hole therethrough and by then inserting an instrument to hammer the tongue latch 72 away from behind the keeper 74; the guard 80 thus provides additional protection.

In order to operate the lock mechanism as previously described, a key must be inserted into each of the respective key slots 46, 48 and simultaneously turned for meshing engagement between gears 64, 70. The cylinders 42, 44 may be adapted to operate with interchangeable or dissimilar keys. However, both keys must be inserted at the same time and each must be rotated in order to displace the tongue latch 72 into the locked or unlocked position. The mechanism is therefore extremely difficult to pick since both of the cylinders 42, 44 must be operated simultaneously.

An alternate application of the lock mechanism is illustrated in FIG. 8 wherein the cylinders 42', 44' are mounted in a door 18' and mating gears 64', 70' are simultaneously rotatable in meshing engagement as described with respect to the previous embodiment, to operate a latch bolt mechanism 100 within a rim type lock 102. Each of the lock cylinders 42', 44' is mounted through a separate cylinder opening and is readily adapted for use with the conventional rim lock 102.

The embodiment does not employ a radial extension from a gear member or tongue latch, however, one of the cylinders 44' is provided with a tail extension 104 projecting rearwardly from and rotatable during the simultaneous operation of both cylinders 42', 44'. The tail extension 102 serves as the actuating means in place of the previously described tongue latch, for operating the lock.

As other possible embodiments might be made of the present invention and various changes might be made in the embodiment set forth, it is to be understood that all matter herein described or shown is to be interpreted as illustrative and not in a limiting sense.