BACKGROUND

Tamper proof â€œsecurity screwsâ€ and nuts have been used to prevent or frustrate vandals and petty thieves. These are used, for example to secure wheel rims to automobiles or protect against unauthorized removal of license plates. Some security screws rely upon a screw head having an unusual shape that requires a special tool to be used. Other security screws may have an asymmetric one-way, clutch head design that allows for easy attachment but not for removal. Alternatively, a threaded cap requiring a special tool to remove the cap may be used to hinder access to a traditional screw, as shown for example in D621,2545.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a license plate securely attached to an automobile in accordance with an embodiment of the invention.

FIG. 2 shows security covers being used to securely attach a license plate to an automobile in accordance with an embodiment of the invention.

FIG. 3 and FIG. 4 show a disassembled security cover in accordance with an embodiment of the invention.

FIG. 5 shows a simplified cross-section of a disassembled security cover in accordance with an embodiment of the invention.

DESCRIPTION OF THE EMBODIMENT

FIG. 1 shows a license plate 10 securely attached to an automobile 9 using screws covered by a security cover 21 and a security cover 22.

FIG. 2 shows additional details of security cover 21 as assembled. Particularly, a cap 12 and a ring 13 both spin freely when security cover 21 is attached to automobile 9. A hole 14 is used to attach and remove secure security cover 21, as is further described below.

FIG. 3 and FIG. 4 show security cover 21 in a disassembled state. To assemble, a screw 18 is placed through an anchor 20. Herein, screw is used generically to refer to screws, bolts or any other attachment device that uses helical threads for secure attachment. For example screw 18 is a standard screw that may have a head shaped to receive a Phillips screwdriver or a flat head screwdriver. Alternatively, screw 18 may have another standard or non-standard shaped screw head. Anchor 20 is placed within container 17 while screw 18 is placed through a hole in license 10 and screwed into a threaded hole 16 in automobile 10. When tightened, screw 18 holds anchor 20 tightly against license 10. Anchor 20 and the inside of container 17 are shaped so that when screw 18 is tightened, container 17 can be freely rotated while being securely prevented from removal from license 10 and automobile 9.

Cap 12 includes internal screw threads (shown in FIG. 5) that match external screw threads on an external surface of a portion of container 17, as shown in FIG. 3.

Ring 13 is located over the unthreaded portion of container 17 and rotated so that a hole 15 in ring 13 is aligned with a hole 19 in container 17. Placing a pin 14 through hole 15 and hole 19 allows a user to prevent rotation of container 17 when cap 12 is screwed on to container 17 or when cap 12 is screwed off of container 17. Once license plate 10 is attached to automobile 9, hole 15 can be filled in, for example, using solder, glue, or some other filling material, when it is desired to increase the difficulty of removing screw 18 from hole 16.

For example parts of security cover 21 and security cover 22 are made of steel, another suitable metal, alloy or other hard material, such as a very hard plastic.

FIG. 3 additionally shows an optional set screw 53 that can be used after license place 10 is attached to automobile 9 and cap 12 is mounted on container 17. Threaded hole 51 on cap 51 is aligned with hole 52 on container 17 and set screw 53 is screwed in. For example, set screw 53 is a hex key or Allen key that can be screwed in using an Allen wrench. Alternatively, set screw 53 can have another type of screw head or bolt head. This provides one more layer of protection to removal of license plate 10.

FIG. 5 shows a simplified cross-section of disassembled security cover 21. When screw 18 is tightened against license 10, a bottom face 44 of a narrowed ring 42 of anchor 20 is pressed against license 10. A lip region 41 of anchor 20 locks a lip region 43 of container 17 against license 10. A length 31 of narrowed ring 42 is slightly longer than a width 32 of lip region 43. This gives sufficient slack so that container 17 can still rotate freely even when screw 18 tightly holds anchor 20 against license 10.

The foregoing discussion discloses and describes merely exemplary methods and embodiments. As will be understood by those familiar with the art, the disclosed subject matter may be embodied in other specific forms without departing from the spirit or characteristics thereof. Accordingly, the present disclosure is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.