Patent Application
20130303294
1. Technical Field
The present invention relates to thread repair devices, and more particularly to a tool for repairing damaged male threads.
2. Description of Related Art
Thread repair tools are designed for repairing screw threads with thread cutting molds having corresponding screw diameters. One conventional thread repair tool, as disclosed in Japan Patent Publication No. 2006-326731A, is composed of two die halves that only fit threads of a certain thread pitch, screw diameter and screw type. For repairing threads with different designs, the conventional tool would need plenty of said dies, being inconvenient to both carry and use.
The primary objective of the present invention is to provide a thread repair tool that is capable of dealing with screws of various diameters, without using different dies.
According to the present invention, a thread repair tool used for repairing a set of damaged threads on a screw comprises a tool body having at least one surface provided with a thread repair blade that has a tooth pitch identical to a thread pitch of the set of threads, plural rollers separated from the tool body by a gap, and an adjusting means for such adjusting the gap that the screw is firmly held between the tool body and the rollers.
Thereby, the disclosed thread repair tool has the distance between the thread repair blade and the rollers adjusted to fit the to-be-repaired screw's diameter, thereby facilitating threads repair operation. This allows the disclosed thread repair tool to adapt itself to screws with different diameters, opposite to the prior-art device that needs many dies. It is thus evident that the present invention overcomes the shortcomings of the prior art.
The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
While a preferred embodiment provided hereinafter for illustrating the concept of the present invention as described above, it is to be understood that the components of the embodiment shown in the accompanying drawings are depicted for the sake of easy explanation and need not to be made to exact scale.
Please refer to
The tool body 10 has at least one surface provided with a thread repair blade 11 constructed from a row of teeth. The thread repair blade 11 has a tooth pitch matching the thread pitch of a set of threads to be repaired. In the present embodiment, the tool body 10 is a rectangular plank with its four lateral surfaces each provided with a thread repair blade 11, 12, 13 or 14. Preferably, the thread repair blades 11, 12, 13 and 14 on the different surfaces have different tooth pitches. Thereby, a single said tool body 10 is useful to repair screws of different thread pitches. In practice, more than one said tool bodies having different thread repair blades may be provided to adapt the thread repair tool to screws of more different specifications.
The rollers 20 are separated from the tool body 10 by a gap. Preferably, as shown in
The adjusting means includes a base 30, an adjusting screw 40 and a sliding block 50. The base 30 has a lengthwise sliding guide 31, and the rollers 20 are mounted on the base 30 to roll with respect to the base 30. The tool body 10 is deposited on the sliding block 50. Preferably, the tool body 10 is detachably fixed to the sliding block 50. For example, the sliding block 50 is formed with an assembling hole 52, and the tool body 10 is centrally provided with a through hole 17, so that a fixing screw 15 passing through a gasket 16 and the through hole 17 of the tool body 10 can engage with threads formed in the assembling hole 52 of the sliding block 50 to fix the tool body 10 on the sliding block 50. The sliding block 50 is slidably mounted on the sliding guide 31 so it can linearly slide in a sliding direction. The sliding block 50 has a threaded hole 51. The adjusting screw 40 is such assembled to the base 30 in the sliding direction that it is rotatably independent of the base 30 and then engages with the threaded hole 51. By stating that the adjusting screw 40 “is rotatably independent of the base 30”, it means that when rotating, the adjusting screw 40 does not slide axially with respect to the base 30. Thereby, the rotation of the adjusting screw 40 makes the sliding block 50 slide along the sliding guide 31, thereby varying the gap.
Referring to
In an alternative operation of the present invention, for achieving relative rotation between the screw 1 and the thread repair tool, it may be the case where the thread repair tool is held still, and the screw 1 revolves while being held by the thread repair blade 11 and the rollers 20, so as to similarly repair the threads 2.
Referring to
A main advantage of the present invention is that the thread repair tool can fit screws with different diameters by adjusting the gap between the tool body and the rollers, without needing many dies as the prior-art device does, making the tool convenient to use.
Another advantage of the present invention is that the single tool body can have multiple thread repair blades so as to match screws with both forward and backward threads, screws with different thread pitches, and/or screws of different types, making the tool more applicable.
Still another advantage of the present invention is that it allows the threads under repair to be visible to the relevant operator so that the operator can perfectly repair the threads by applying different levels of pressing force to the thread repair blade.
The present invention has been described with reference to the preferred embodiments and it is understood that the embodiments are not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims.
