Wheel lug nut security seal

[0002] The present application claims the benefit of U.S. Provisional Appln. No. 60/316,937, filed Sep. 5, 2001.

[0003] 1. Technical Field of the Invention

[0004] The present invention is directed to a security seal assembly designed to provide detection of tampering with or the removal of a wheel lug nut, particularly on a truck tire. The security seal is designed as an indicative seal rather than theft seal. When the seal is fitted onto the wheel lug nut, it prohibits access to the nut unless the cover is broken.

[0005] 2. Prior Art

[0006] U.S. Pat. Nos. 4,324,516 and 4,645,397 are inventions with the same purpose but of different design. Both these designs can be removed undamaged and re-fitted without detection if certain conditions apply when the seal is originally fitted.

[0007] There are several security seals for vehicle wheels, particularly trucks, on the market and the security seal has been in use for more than 15 years. Security seals for wheel lug nuts are basically either a lock seal or an indicative seal. The lock seal is design to prevent removing the lug nut unless some special tool is used. This seal can often be reused and is therefore expensive to manufacture. The indicative seal is however inexpensive and designed to be a one time use only, once it is fitted it cannot be removed unless it is broken. The idea is that a broken or missing indicative seal is easy to detect by a quick visual inspection and this will then initiate an investigation by the equipment owner of unauthorized removal and replacement of a wheel or tire from a vehicle while in the care of a third party, domestically or abroad.

[0008] Prior art designs of the indicative seal have however not proven to be effective. Under some circumstances such as a short lug nut, they can be removed intact and refitted without detection when inspected. Some designs have also proven to be difficult to fit properly, resulting in fitted seals that can be removed without detection.

[0009] The primary object of the invention is directed to providing an indicative seal that eliminates the problems of the prior art indicative seal devices but remains simple and economical to manufacture and use.

[0010] FIG. 1 shows an exploded view of the indicative seal according to the invention and the conventional wheel stud and nut to which the seal will engage.

[0011] FIG. 2 is an elevation view of the indicative seal of FIG. 1 in combination with the wheel stud and nut.

[0012] FIG. 3 is a top view of the indicative seal of FIG. 2.

[0013] FIG. 4 is a cross-section along section line 4—4 of FIG. 2

[0014] As depicted in FIGS. 1-4, the present invention is an indicative seal assembly 1 consisting of three plastic parts: 1) a nut cover 2, 2) a cap 4, and 3) a stud nut 6.

[0015] The nut cover 2 has a hole 8 through which a conventional wheel stud 10 can be inserted and is shaped for corresponding engagement over a nut 12 on the wheel stud 10. Locking teeth 14 are formed to project up from the circumference of hole 8 of the nut cover 2.

[0016] The cap 4, which is to be engaged over the nut cover 2, has an outer wall 15 which can be conical and an inner tubular wall 16 extending down within the outer wall 15 from the circumference of a hole 17 in the top wall 19 of the cap 4. A circular ledge 18 at the bottom end of the inner tubular wall 16 projects in from the inner circumference of the tubular wall 16.

[0017] The stud nut 6 has a tubular wall 20 extending down from a top wall 22 and a circular ledge 24 near the bottom end of the tubular body 20 that projects out from the outer circumference of the tubular body 20. Locking teeth 26 corresponding to locking teeth 14 of nut cover 2 are formed below ledge 24. The inside threads 29 on tubular body 20 allow the stud nut 6 to be threaded onto the threads 30 of the wheel stud 10 internally of the cap 4 so as to hold down the cap 4 against nut cover 2 when ledge 24 of the stud nut 6 engages ledge 18 of the cap 4. When the stud nut 6 is fully threaded onto the wheel stud 10, as shown in FIG. 4, by rotating the fitting wing 28, the locking teeth 26 of the stud nut 6 are also engaged with the locking teeth 14 on the nut cover 2.

[0018] When the stud nut 6 cannot be tighten any further on the wheel stud 10, additional twisting torque breaks the fitting wing 28 off at the scored or indented line 32 at the bottom of the fitting wing.

[0019] With the fitting wing 28 gone, the force required to back out the stud nut 6 would either shear the locking teeth 14, 26 on the nut cover 2 and stud nut 6 or break the nut cover 2. Since the cap 4 covers the stud nut 6 and the nut cover 2, it is not possible to grip the stud nut 6 with fingers or tools to back it out unless the cap 4 is broken. The cap 4 also freely turns between the stud nut 6 and nut cover 2, making it impossible to turn the stud nut 6 by squeezing and turning the cap 4. The design only requires a short thread on the wheel stud 10 above nut 12 and once the operator is able to twist the stud nut 6 until the fitting wing 28 breaks off, it is a certain and easy indication that the seal is fitted correctly and securely. The outer wall 15 of the cap 4 can be made to be transparent so that a user can attach stickers with seal numbers readable when the security seal assembly is fitted to the wheel stud, thereby alerting the user to any seal with different numbering that might be substituted.

[0020] The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptions and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.