Background of the Invention
It has heretofore been proposed to restrict the access to cylindrical type locks in the walls of cabinets, etc. to prevent tampering with the lock and to prevent theft of the contents of the cabinet.
There have been a number of solutions for protecting the lock by means of a shroud, a keyhole guard, a keyhole stuffer and the like, as exemplified by the disclosures of the following patents.
In U.S. Pat. No. 1,457,702 to Hoff of June 5, 1923, a pair of spaced apart parallel bars with padlock with terminal locking dogs prevent access to the keyhole by filling the keyhole. This invention has the disadvantage of not fitting in small sized keyholes of cylinder type locks and can only fit if the keyhole is of sufficient size, rectilinear and unobstructed. It, therefore, does not have universal application.
In U.S. Pat. No. 1,206,611 to Strode of Nov. 28, 1916 a guard bar covers the keyhole to prevent access to the keyhole, and in U.S. Pat. No. 3,714,804 to French of Feb. 6, 1973 a shutter covers the keyhole. These inventions have the disadvantage of being difficult to install and each requires permanent bolt or rivet attachment to the cabinet so that they are not portable or detachable.
Other types of lock protectors are exemplified in U.S. Pat. No. 1,590,981 to Lockyer, U.S. Pat. No. 3,623,346 to Curtin or U.S. Pat. No. 3,874,204 to Capri wherein a shroud or cover fits over something which is spaced from the wall such as a lock handle or knob and is anchored by a part fitting under the same in the space. These devices would have no utility with the cylinder locks on tool cabinets or tool boxes because they have no projecting hooked parts and no handles or knobs to fit under for padlocking of a cover or shroud.
Summary of the Invention
In this invention, the detachable guard is completely removable when unlocked, but restricts access to the keyhole of cylinder locks in the walls of sheet metal cabinets or the like. The wall of the cabinet supporting the cylinder lock is first provided with two drilled openings of predetermined size each on an opposite side of the lock. The guard consists of a generally U-shaped body formed by a pair of anchor legs joined by, and affixed on, a shouldered rivet. Each of the anchor legs has a free terminal end which has a cut out and a right angular tongue. The tongues fit into the openings to contact the rear face of the wall when the guard straddles the keyhole and the cutouts of the legs engage the front face of the wall.
An elongated locking leg is located between the anchor legs of the U-shaped body and is journalled on the shouldered rivet. The locking leg and each of the anchor legs each have a hole which when the guard is in locked position, register to receive the shackle of a padlock. Alternatively, a lock may be built into the guard.
Brief Description of the Drawing
FIG. 1 is a fragmentary front perspective view of a typical lockable sheet metal tool cabinet with the guard of the invention affixed thereon;
FIG. 2, is an enlarged fragmentary front view of the cylindrical key lock in the front face of the wall of a sheet metal tool cabinet with two openings formed therein;
FIG. 3 is a top plan view of the guard in closed position;
FIG. 4 is a side view thereof;
FIG. 5 is a side view of the guard in open position;
FIG. 6 is an enlarged fragmentary view of the rear face of the wall of the sheet metal tool cabinet with the guard inserted and in locking position;
FIG. 7 is a rear view of the guard in closed position; and
FIG. 8 is a perspective front view of the guard.
FIG. 9 is a plan view, FIG. 10 a front view and FIG. 11 a side view of another embodiment of the invention.
Description of the Preferred Embodiment
The typical sheet metal, tool cabinet 20 shown in FIG. 1 is sometimes called a mechanic's tool chest and cabinet and is used by a mechanic to store tools and other valuables. The cabinet 20 has a plurality of drawers 21 and at least one drawer 18 has a cylinder lock 22. The cylinder lock 22 is usually of the pin-tumbler type and has a keyhole 23 in an annular, truncated conical escutcheon 24 which projects slightly from the chest.
The cylinder lock 22 prevents access to all drawers when locked and is affixed in a wall 25 which has a front face 19 and a rear face 26.
Unlike the complicated permanent, riveted or bolted anchor plates of the prior art, in this invention, anchoring is by merely drilling spaced apart openings 27 and 28 in the wall 25. Since the cabinet 20 is the tool cabinet of a mechanic, the drilling of the openings 27 and 28 as circular quarter inch openings, or preferably, forming the openings as vertical, narrow slots, is an easy task.
The guard 29 comprises a generally U-shaped body 31 consisting of a first anchor leg 32 and a second anchor leg 33. One end of each anchor leg is fast on a shouldered rivet 34 which connects the legs and forms the bight 35 of the U-shaped body. The other free terminal end 36 or 37 of each anchor leg has an elongated, right angular tongue 38 or 39 which is inserted into openings 27 or 28. The front faces 41 and 42 of each tongue 38 and 39 engage the rear face 26 of the wall 25 to secure the guard in place.
The tongue end of each anchor leg has a cut out at 44 or 45 with an upper rear face 46 or 47 which contacts and fits snugly against the front face 19 of wall 25.
Both of the anchor legs 32 and 33 have a central straddle portion 48 or 49 which is outwardly flared at 51 or 52 away from the rivet 34 to follow, and straddle, the contour of the projecting escutcheon 24 of the lock.
The central straddle portions 51 or 52 of each anchor leg are broad to prevent access to the cylinder lock from either side.
A locking leg, or pawl, 57 is journalled on the large diameter portion of the rivet 34. The leg 57 has an elongated shank 58 and is pivotable to move from an open position (FIG. 5) to a closed position (FIG. 4) so that the tip 62 engages the front face of the wall 25.
The rear face 63 of locking leg 57 is cut out at 64 to embrace and intimately contact the escutcheon 24 of the cylinder lock and cover the keyhole 23 to prevent access to the keyhole by lock picking tools, etc.
The bight sections 65 and 66 of the anchor legs and the corresponding section 67 of the locking leg are provided with padlock holes 68, 69, and 71, which register with each other when the guard is in closed position. The padlock holes when in register, receive the shackle 72 of a detachable padlock 73, thereby securing the guard 29 to the drawer 18 and preventing access to the lock 22 and the keyhole 23.
It will be seen that when the tripod-like completely detachable guard 29 is in closed and padlocked position over the cylinder lock 22, the wide straddle portions of the anchor legs prevent access to keyhole 23 from either side while the locking leg prevents access from top or bottom even to a hook shaped lock pick. When unlocked and bodily removed from the front wall of the tool cabinet, there are no projecting parts of the guard assembly on the cabinet and the guard folds into a compact closed tripod, easily stored in the pocket or elsewhere.
As shown in FIGS. 9, 10, and 11, in another embodiment, a cylindrical lock set 81 may be welded to the anchor legs 82 and 83 of a guard 84, with a key hole 85 for a separate key, and with its pivotable pawl 86 normally affixing the locking leg 87 in locked position. When lock set 81 is unlocked, pawl 86 pivots out of the path of leg 87 to permit the leg to pivot relative to the anchor legs 82 and 83 and release the guard 84.