Locks – Operating mechanism – Key
Reexamination Certificate
2001-06-11
2002-09-10
Gall, Lloyd A. (Department: 3676)
Locks
Operating mechanism
Key
C070S252000, C070S380000, C070S466000, C070SDIG003
Reexamination Certificate
active
06446475
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to switchlocks and in particular to a switchlock assembly having a snap-in cam and a latch clip allowing the switchlock assembly to be mounted into a panel cutout smaller than what would be required if the cam was attached to the switchlock assembly prior to mounting in the panel.
2. Description of Related Art
Cam locks are well known in the art and have a wide variety of uses ranging from pay telephones, automatic bank tellers, data processing equipment, parking meters, gas pump meters, burglar alarm controllers, gun racks, and the like.
It is also known in the art to have a combination lock/cam lock design which has a dress nut on the front of the assembly and the assembly is mounted from the rear of the panel. Such a switch is sold by ITT Canon, C & K Components, Inc. of Watertown, Mass., the assignee of the present invention. However, when such a switch is mounted from the rear of the panel, the lock can be easily defeated by a wrongdoer removing the dress nut and removing the lock from the panel.
U.S. Pat. No. 4,829,798, entitled “Combination Switch Lock/Cam Lock Assembly” issued May 16, 1989 to Stevie C. Roop and assigned to Medeco Security Locks, Inc., of Salem, Vt., discloses a high security combination lock/cam lock assembly which is resistant to defect and does not have a dress nut which can be unthreaded to defeat the lock. The combination lock comprises a one-piece shell, a plug with a tenon, an electrical switch, and a cam which is insertable from the front face of a panel opening by not affixing the cam until after the lock is inserted in the panel. However, the present invention engages the plug directly with the snap-in cam whereas in the prior art the retainer engages with the plug. Also, the latch clip in the present invention locates the shell on the plug in an axial direction but allows rotation of the plug in the shell. The prior art relied on a retaining ring for this axial retention.
U.S. Pat. No. 2,257,741, entitled “LOCK”, issued Oct. 7, 1941 to R. L. Gray and assigned to Illinois Lock Company discloses a lock operated by a key useful for a desk draw comprising a barrel adapted for fixed attachment to another structure and provided with a plug rotatable in response to operation of a key, a guideway substantially opposite a keeper, a bolt movable to engage or disengage the keeper and provided with a shank and compression spring actuated to extend eccentrically from the plug end in sliding engagement with the shank adapted to establish a pivotal locking connection between the plug and the bolt. However, this design requires the use of a compression spring.
U.S. Pat. No. 2,278,044, entitled “LOCK”, issued Mar. 31, 1942 to R. A. Scanlan and assigned to American Hardware Corporation discloses a key operated lock that is simple in construction and efficient in operating. It is used with metal office furniture. The lock comprises a cylinder with a plug rotatably mounted in the cylinder and has a key slot for a key. In the operation of assembling the device the cylinder is secured in place by means of a nut. The bolt is then inserted through the hole in the upper edge of the drawer and into the opening through the cylinder the detent having an inclined edge which coming in contact with the opening in the cylinder, will cause the detent to be depressed against the tension of the spring and therefore permit the bolt to be inserted until shoulders on the bolt come in contact with the edges of the openings through the cylinder. In this operation of inserting the bolt, the actuating pin should be turned by means of a key. When the bolt is fully inserted the detent will snap into its locking position. A retainer in an annular groove in the wall of the bore retains the key plug in the cylinder. However, this switch design is expensive to produce.
U.S. Pat. No. 2,962,888 entitled “LOCK”, issued to R. W. Ahlquist, and assigned to American Hardware Corporation discloses a key operated cylinder lock of the type commonly used on desk draws and other closures for locking them in a closed position. The lock comprises a cylinder, a bolt and a spring member which permits the bolt to be assembled to the lock cylinder without removing the key plug. However, this switch requires the use of a retaining bar for the spring.
U.S. Pat. No. 5,479,800 entitled “PLASTIC LOCK”, issued Jan. 2, 1996 to G. L. Myers, and assigned to Fort Lock Corporation discloses a key lock mechanism which can be made entirely of molded plastic parts comprising a lock shell that can be snap fit in a mounting opening wherein the shell is predominantly a cylindrical casing, and a lock plug within and rotatable about the longitudinally axis of the shell. The rear end of the plug receives a snap on actuation means such as a cam with a securing ramp which snaps into a securing notch. However, this lock design uses a plastic bolt not having the strength of a metal bolt.
SUMMARY OF THE INVENTION
Accordingly, it is therefore an object of this invention to provide a switchlock assembly with a snap-in cam and a latch clip to allow the switchlock assembly to be mounted into a panel cutout smaller than what would be required if the cam was part of the switchlock assembly prior to mounting of the switchlock assembly in the panel.
It is another object of this invention to provide a switchlock assembly that allows a key to be pulled out in a designated position, but not to allow the key to be pulled out 180 degrees from the designated key pull position, even though a plug of the switchlock assembly can be rotated into either position.
It is a further object of this invention to provide a switchlock assembly that mounts to a panel from the front of the panel and is secured by a spring clip prior to insertion of a snap-in cam.
These and other objects are accomplished by a switchlock assembly for mounting in a panel comprising a cylindrical shell having a circumferential opening in a side of the shell, a lock plug positioned within the cylindrical shell having a keyway entering at a first end and a switch driver extending axially from a second end of the lock plug, a switch base mounted on an end of the shell having an opening for receiving the switch driver from the second end of the lock plug, a latch clip inserted within the circumferential opening of the shell and into a clip slot on a side of the lock plug for securing the latch clip within the lock plug, and a cam, having a first portion inserted into the circumferential opening in the side of the shell, snaps into the lock plug adjacent to the latch clip, a second portion of the cam extending outside the diameter of the switchlock assembly, the cam freely rotating with the plug. The lock plug rotates in accordance with a turning of a key inserted into the keyway, thereby rotating the cam. The cylindrical shell comprises a flanged head at an outer end, the flange being recessed to receive a head portion of the plug whereby a base of the plug is flush with a face of the shell. The lock plug comprises a plurality of tumbler slots for receiving a plurality of tumblers operated by the key inserted in the keyway. The clip slot in the side of the cylindrical plug comprises means for securing a retention tab of the latch clip to prevent removal of the latch clip from the plug. The latch clip inserted in the switchlock assembly extends outwardly to at least the outside diameter of the shell thereby preventing the plug from being removed from the shell. The first portion of the cam comprises a slot for receiving a cam retention tab of the adjacent latch clip thereby preventing the cam from being removed from the switchlock assembly. The latch clip comprises a first retention tab extending at an acute angle in a first direction and a second retention tab extending at an acute angle in a second direction opposite the first direction, the first retention tab snapping into an internal surface of the plug for securing the latch clip within the plug. The latch clip retains the lock plug within the
Agnatovech William Joseph
Ehrensberger Robert
Gall Lloyd A.
Pearson & Pearson LLP
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