Patent Application
20110314973
1. Field of Invention
The present invention relates to a wrench and, more particularly, to a well coated wrench.
2. Related Prior Art
A wrench is generally made of metal for excellent rigidity. However, a user might get an electric shock while operating a metal wrench.
To avoid an electric shock, handles of some metal wrenches are coated with an isolative material such as rubber and plastics. However, a user might touch another portion of a metal wrench with a rubber or plastics-coated handle and get an electric shock.
To effectively avoid an electric shock, a well coated wrench is devised referring to
The well coated wrench is tested in an isolation-testing machine before it is made available on the market. The well coated wrench is buried in steel balls 6 after the tongue 3 is located in an isolative cup 7. It is determined whether there is any current between the steel balls 6 and the one-way mechanism. The annular ridge 8 is expected to prevent the steel balls 6 from entering the tunnel 2 and reaching the one-way mechanism. However, the steel balls 6 could get really close to the one-way mechanism when the button 4 is not pushed because an external diameter of the annular ridge 8 is smaller than an internal diameter of the button 4. Therefore, the well coated wrench could fail the test by mistake.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
It is the primary objective of the present invention to provide a well coated wrench that does not fail an isolation test by mistake.
To achieve the foregoing objective, the well coated wrench includes a metal element, a one-way mechanism and an isolative coating. The metal element includes a tunnel defined therein. The one-way mechanism is substantially located in the tunnel. The one-way mechanism includes a tongue located outside the tunnel and a button located outside the tunnel. The isolative coating is provided on the metal element. The isolative coating includes an external annular ridge located around the button.
Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.
The present invention will be described via detailed illustration of the preferred embodiment versus the prior art referring to the drawings wherein:
Referring to
The one-way mechanism 20 is substantially located in the tunnel 14. The one-way mechanism 20 includes a tongue 21 located outside the tunnel 14. The tongue 21 is also made of metal. The tongue 21 is not coated with any isolative material such has rubber and plastics for precise size and excellent rigidity. A detent 23 is attached to the tongue 21. The detent 23 includes a first portion located in the tongue 21 and a second portion that is normally located outside the tongue 21.
A button 22 is operable to release the detent 23 so that the second portion of the detent 23 can be moved into the tongue 21. The button 22 is formed with an annular edge 24. The button 22 is made of an isolative material such as rubber and plastics.
In use, the button 22 is pushed to release the detent 23 so that the second portion of the detent 23 can be moved into the tongue 21. The tongue 21 is inserted in a socket. The button 22 is released so that the second portion of the detent 23 is located outside the tongue 21 again to retain the socket connected to the tongue 21. By pivoting the well coated wrench 100 to and fro, the socket is spun in a selected one of two opposite directions because of the one-way mechanism 20.
The isolative coating 13 is made of an isolative material such as rubber and plastics. The isolative coating 13 covers the metal element 10. That is, the isolative coating 13 covers the shank 11, the handle 12 and the head 18. The isolative coating 13 includes an internal annular ridge 15 around the tunnel 14 and an external annular ridge 16 around the internal annular ridge 15. An external diameter of the internal annular ridge 15 is marginally smaller than an internal diameter of the annular edge 24. An internal diameter of the external annular ridge 16 is marginally larger than an external diameter of the annular edge 24. The width of the gap between the annular ridges 15 and 16 is substantially identical to the thickness of the annular edge 24. Thus, the annular edge 24 is in contact with both of the annular ridges 15 and 16.
The well coated wrench 100 is tested in an isolation-testing machine before it is made available on the market. The well coated wrench 100 is buried in steel balls 98 after the tongue 21 is located in an isolative cup 99. It is determined whether there is any current between the steel balls 98 and the one-way mechanism 20. Both of the annular ridges 15 and 16 are in contact with the annular edge of the button 22. Thus, the annular ridges 15 and 16 affectively prevent the steel balls 98 from entering the tunnel 14 and reaching the one-way mechanism 20 when the button 22 is not pushed. Therefore, the well coated wrench would not fail the test by mistake.
The present invention has been described via the detailed illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.
