1. Field of the Invention
The present invention relates to hand tools; and more specifically the invention relates to locking head for tools at the end of handles; more specifically still, the invention relates to a locking head for a pick axe.
2. Description of the Related Art
Historically hand tools such as axes, pick axes, hammers, etc., have had a tapered handle that locks the head of the tool at the end of the handle. Typically, the handle is simply a shaft which is tapered to a larger diameter at the end where the tool is located. The taper of the handle matches the inside surface of the tool head so that a frictional arrangement is possible between them. In order to secure the tool at the end of the handle, the tool collar is placed around the handle and urged down the shaft to the tapered end. The head is locked into the handle by the interference fit between the tapered surfaces.
One problem arising in the prior art designs is due to the frictional fit and its likelihood of loosening when the tool is in use. For example after use and wear on the tool, the head can become loose and slide down the handle. The use of cement between the handle and head tends to become ineffective over time. The loosening heads can cause serious damage to people using the hand tool and to personal property.
Therefore, a need exists for an improved apparatus and method for locking the head of a hand tool to the handle.
Embodiments of the present invention are generally directed to an apparatus for locking the head of a hand tool to the handle of the tool. In one embodiment, the apparatus includes a handle with a tapered tool end and a gripping end. The head of the tool has a correspondingly tapered inner surface and is placed on the handle and urged towards the tool end of the handle. The head of the tool slides into place and becomes fixed on the handle due to the tapered surfaces of the handle and tool head. With the head in place, a portion of the compressible material between the handle and the head becomes compressed. However, a portion of the compressible material not covered by the head retains its non compressed thickness and serves as a stop to prevent the tool head from moving back down the handle.
In yet another embodiment, the tool end of the handle has one or more grooves formed in the handle. Each groove is filled with a compressible material that runs substantially the length of the groove.
In yet another embodiment, the present invention is directed to a method for locking a tool to the end of a handle. The tool is locked by placing one or more compressible members on the tool end of a handle and placing the tool around the handle. The tool is then moved so that the tool is over a portion of the compressible member. Friction is used to cause the compressible member to lock the tool into place.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
The grooves (400) in the handle at least partially house a compressible member (401). The depth of the groove (400) can be any depth so long as the compressible member (401) fits within the groove (400). The grooves (400) are long enough so that a portion of the groove (400) and a corresponding portion of the compressible member (401) will be outside the collar (301) of the tool head (300) while a portion will be under the collar (301) of the tool head (300) when the tool is assembled. In the embodiment shown there are four grooves (400) spaced symmetrically around the handle. It should be appreciated that the one or more grooves (400) could be at any location around the handle so long as a portion of the groove (400) extends under the collar of the tool head.
The compressible member (401) can be made of any material so long as it will compress and allow the collar (301) to slide over it as the tool is assembled. The compressible member (401) can be attached to the handle itself in the groove, or just rest in the groove (400). It should be appreciated that the compressible member (401) could be used without a groove by placing it on the smooth surface of the handle. The compressible member (401) will assist in locking the tool head (300) into place on the handle as described below.
With the tool head (300) in place, the compressible member (401) assists in locking the tool head (300) to the handle. The compression of a portion of the compressible member (401) between the collar and the tool head causes a portion of the compressible member (401) at the edge of the collar (301) to rise up as shown in FIG. (3). The raised portion (402) of the compressible member (401) forms a stop and assists in locking the tool head (300) on the handle.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims benefit of U.S. provisional patent application Ser. No. 60/582,437, filed Jun. 23, 2004, which is herein incorporated by reference.
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Number | Date | Country | |
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20050284264 A1 | Dec 2005 | US |
Number | Date | Country | |
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60582437 | Jun 2004 | US |