FASTENER CAP

Abstract

A fastener cap includes a shank having a longitudinal hole with a closed first end and an open second end. The shank further includes at least one engaging section on an inner wall delimiting the longitudinal hole. The engaging section has an inner diameter smaller than that of a remaining portion of the longitudinal hole. The engaging section is engaged with threading of an exposed portion of a shank of a screw and thus shields the exposed portion of the shank of the screw. The closed first end of the fastener cap improves the rust-preventing effect for the screw.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fastener cap. More particularly, the present invention relates to a fastener cap for covering an exposed portion of a fastener such as screw, bolt, etc.

2. Description of the Related Art

Screws and bolts made of steel or the like provide excellent fastening effect. However, the threaded shank of a screw or bolt is apt to rust due to contact with air or water, resulting in damage in the threading as well as getting stuck. As a result, the screw or bolt could not be detached when desired. This is particularly true for the exposed threaded portion of a headless screw or bolt.

FIGS. 1 and 2 of the drawings illustrate a conventional fastener cap 2 for covering an exposed portion of a shank 11 of a screw 1. The fastener cap 2, generally made of plastic, is substantially a cylindrical member with a longitudinal through-hole 21, allowing it to be mounted around and thus protect the exposed portion of the shank 11 of the screw 1. The fastener cap 2 has an inner diameter slightly greater than a diameter of the shank 11 for protecting the exposed portion of the shank 11 from rusting due to contact with ambient air or moisture. The life of the screw 1 can be prolonged accordingly.

However, the inner circumference of the fastener cap 2 and the outer circumference of the exposed portion of the shank 11 of the screw 1 have no reliable engagement therebetween such that the fastener cap 2 is apt to be disengaged from the shank 11 of the screw 1. In a case that the diametrical dimension of the longitudinal through-hole 21 of the fastener cap 2 is precisely controlled to be in a small tolerance for mating with the diameter of the exposed portion of the shank 11 of the screw 1 for providing a firm engagement therebetween, a problem might arise that, due to expansion and shrinkage resulting from temperature change, the longitudinal through-hole 21 of the fastener cap 2 becomes so small that the fastener cap 2 could not be mounted around the exposed portion of the shank 11 of the screw 1. Further, ambient air or moisture may enter the fastener cap 2 via the open end of the fastener cap 2, resulting in undesired rusting.

SUMMARY OF THE INVENTION

A fastener cap in accordance with the present invention comprises a shank includes a longitudinal hole that includes a closed first end and an open second end. The shank further comprises at least one engaging section on an inner wall delimiting the longitudinal hole. The at least one engaging section has an inner diameter smaller than that of a remaining portion of the longitudinal hole. The at least one engaging section is adapted to engage with threading of an exposed portion of a shank of a screw.

Since the first end of the fastener cap is closed, the exposed portion of the shank of the screw is well shielded from ambient air and moisture. The rust-preventing effect is improved. Damage to the exposed portion of the shank of the screw resulting from impact is also mitigated and/or obviated. Further, the inner diameter of the at least one engaging section of the fastener cap is slightly smaller than the diameter of the exposed portion of the shank of the screw so that the tubular shank of the fastener cap is firmly engaged with the threading of the exposed portion of the shank of the screw.

Preferably, the longitudinal hole of the fastener cap has a diameter slightly greater than that of exposed portion of the shank of the screw.

Preferably, the at least one engaging section includes an annular teeth.

Preferably, the at least one engaging section is substantially triangular in section.

Preferably, the fastener cap further comprises a head on the closed first end thereof.

Preferably, the at least one engaging section is formed on an intermediate portion of the inner wall of the tubular shank of the fastener cap.

Other objectives, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a screw and a conventional fastener cap.

FIG. 2 is a sectional view of the screw and conventional fastener cap in FIG. 1.

FIG. 3 is a perspective view, partly cutaway, of a fastener cap in accordance with the present invention.

FIG. 4 is a perspective view, partly exploded, of a vehicle sideview mirror and a fastener cap in accordance with the present invention.

FIG. 4A is an enlarged view of a circled portion in FIG. 4.

FIG. 5 is a sectional view illustrating use of the fastener cap in accordance with the present invention with an exposed portion of a shank of a screw of the vehicle sideview mirror.

FIG. 6 is an exploded perspective view of a partially embedded screw and the fastener cap in accordance with the present invention.

FIG. 7 is a sectional view of the screw and the fastener cap in FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 3, a fastener cap 4 in accordance with the present invention can be mounted around, e.g., an exposed portion of a shank 31 of a screw 3 of, e.g., a vehicle sideview mirror 5. In this embodiment, the fastener cap 4 comprises a tubular shank 41 including a longitudinal hole 411. More specifically, the tubular shank 41 includes a closed first end 42 and an open second end 43. A head (not labeled) may be formed on the closed first end of the tubular shank 41.

The longitudinal hole 411 includes at least one engaging section 44 (two in this embodiment) on an inner wall of the tubular shank 41 delimiting the longitudinal hole 411. The tubular shank 41 has an inner diameter (i.e., the diameter of the longitudinal hole 411) slightly greater than a diameter of a shank 31 of a screw 3 to be covered. Each engaging section 44 has an inner diameter smaller than the remaining portion of the longitudinal hole 411. Preferably, the engaging sections 44 are formed on an intermediate portion of the inner wall of the tubular shank 41. In this embodiment, each engaging section 44 includes an annular tooth projecting radially inward from the inner wall of the tubular shank 41, and the engaging sections 44 are spaced along a longitudinal direction of the tubular shank 41.

Referring to FIGS. 4, 4A, and 5, the fastener cap 4 can be mounted to a screw 3 of a vehicle sideview mirror 5 via the open second end 43 of the fastener cap 4 for shielding an exposed portion of a shank 31 of the screw 3. Since the inner diameter of the tubular shank 411 is slightly greater than the diameter of the shank 31 of the screw 3, the exposed portion of the shank 31 of the screw 3 can be covered and thus shielded by the tubular shank 411 of the fastener cap 4, preventing the exposed portion of the shank 31 of the screw 3 from rusting due to contact with ambient air or moisture. Since the inner diameter of each engaging section 44 of the fastener cap 4 is slightly smaller than the exposed portion of the shank 31 of the screw 3, the engaging sections 44 of the fastener cap 4 are engaged with the threading of the exposed portion of the shank 31 of the screw 3.

In the illustrated embodiment, the annular tooth of each engaging portion 44 is substantially triangular in section, which is particularly useful to bite into a thread groove (not labeled) of the exposed portion of the shank 31 of the screw 3, providing a firm engagement between the exposed portion of the shank 31 of the screw 3 and the tubular shank 41 of the fastener cap 4, as shown in FIG. 5. Thus, the fastener cap 4 can be easily mounted to the exposed portion of the shank 31 of the screw 3 while allowing a firm engagement between the exposed portion of the shank 31 of the screw 3 and the tubular shank 41 of the fastener cap 4.

Since the first end 42 of the fastener cap 4 is closed, the exposed portion of the shank 31 of the screw 3 is well shielded from ambient air and moisture. The rust-preventing effect is improved. Damage to the exposed portion of the shank 31 of the screw 3 resulting from impact is also mitigated and/or obviated.

Referring to FIGS. 6 and 7, the fastener cap 4 in accordance with the present invention can be mounted around an exposed portion of a shank 61 of a screw 6 that is partially embedded in a concrete wall or the ground. Similar to the use with the screw 3 of the vehicle sideview mirror 5 in FIG. 5, the exposed portion of the shank 61 of the screw 6 is well shielded by the fastener cap 4. Damage to the exposed portion of the shank 31 of the screw 3 resulting from impact is also mitigated and/or obviated.

As apparent from the foregoing, the fastener cap 4 in accordance with the present invention can be used to protect the exposed portion of the shank 31, 61 of a screw 3, 6 while providing a firm engagement with exposed portion of the shank 31, 61 of a screw 3, 6. Further, manufacturing of the fastener cap 4 in accordance with the present invention is easy and thus has a low cost, as it is unnecessary to precisely control the diametrical dimension of the longitudinal hole 411 of the tubular shank 41 of the fastener cap 4 to be in a small tolerance for mating with the diameter of the exposed portion of the shank 31, 61 of the screw 3, 6.

Although specific embodiments have been illustrated and described, numerous modifications and variations are still possible without departing from the essence of the invention. The scope of the invention is limited by the accompanying claims.

Claims

1. A fastener cap comprising:

a shank comprising a longitudinal hole, the shank further comprising a closed first end and an open second end, the shank further comprising at least one engaging section on an inner wall delimiting the longitudinal hole, said at least one engaging section having an inner diameter smaller than that of a remaining portion of the longitudinal hole, said at least one engaging section being adapted to engage with threading of an exposed portion of a shank of a screw.

2. The fastener cap as claimed in claim 1 wherein the longitudinal hole of the fastener cap has a diameter slightly greater than that of exposed portion of the shank of the screw.

3. The fastener cap as claimed in claim 1 wherein said at least one engaging section includes an annular teeth.

4. The fastener cap as claimed in claim 1 wherein said at least one engaging section is substantially triangular in section.

5. The fastener cap as claimed in claim 1 wherein the fastener cap further comprises a head on the closed first end thereof.

6. The fastener cap as claimed in claim 1 wherein said at least one engaging section is formed on an intermediate portion of the inner wall of the tubular shank of the fastener cap.