This invention relates to a shock-absorbing handle for a tool, and in particular a shock-absorbing handle for hand tools such as shingle removal tools, spades, shovels, pitch forks and the like.
The use of hand tools dates to the stone age, when humans first used stones for hammering and cutting. In time, both the materials and design of hand tools have evolved to provide users with greater comfort and more effective operation. These improvements have included modifications to the hand tool's working end and handle.
The working end may be broadly understood to include the distal portion of the hand tool that has an implement attached for contact with a workpiece. The implement is designed to provide the desired effect when it comes into contact with the workpiece; one non-limiting example would be a spade head (implement) that is adapted to easily remove soil from the ground (workpiece). The implement is also adapted to attach to the handle, which is designed to assist the user in holding and manipulating the working end of the hand tool; one non-limiting example of a handle includes a shaft and a grip that is proximal to, and engaged by, the user.
The evolution of hand tools has included numerous changes to the handle that provide for easy replacement, reduced weight, and improved ergonomics. To date, however, efforts to modify hand tool handles to minimize the impact stresses users feel when working with hand tools that strike, or are driven into, a workpiece have been largely unsuccessful. For example, the addition of a padded portion to the handle grip has been insufficient to reduce impact stresses passed along to the user during operation. Design changes to hand tool handles that permit movement of the working end relative to the handle have also been ineffective, as the torsional forces generated during use cause unacceptable torsional movement of the implement.
The general object of the present invention is to provide a new and improved handle for a hand tool, wherein the handle is characterized by shock-absorbing qualities that minimize impact stresses generated during use. It is also an object to provide a shock-absorbing hand tool handle that is highly resistant to torsional forces and can maintain proper position of the implement during use.
Particular embodiments of the present invention include an apparatus comprising a hand tool handle and an implement adapted for use with an associated workpiece, wherein the hand tool handle comprises a shock-absorbing assembly for absorbing impact forces and resisting torsional movement caused by the implement's contact with the associated workpiece.
Embodiments of the present invention also include a method of using a hand tool comprising applying a force to the hand tool, the hand tool comprising a hand tool handle and an implement. The implement is arranged at a distal end of the hand tool, and the hand tool handle comprises a shock-absorbing assembly. The method further includes contacting workpiece with the implement, wherein the shock-absorbing assembly absorbs impact forces and resists torsional movement caused by the implement's contact with the workpiece.
These and other features and advantages of the present invention will be apparent to those of skill in the art in view of the following written description and drawings.
An example of a shock-absorbing hand tool 1 in accordance with one embodiment of the present invention is shown in
The working end is situated at the end distal to the user's hands and includes one or more implements 4 that are configured to effect a change to an associated workpiece. By way of non-limiting examples, with reference to
The hand tool handle 10 may include a shaft 20, a grip 40 and a shock-absorbing assembly 60. The grip 40 may be situated at the end proximal to the user's hands, and adapted to facilitate handling and use of the hand tool 1, and may be configured in any shape or size chosen with sound engineering judgment, including particularly the form of a D-grip 42. The grip 40 may be adapted for operative attachment to the shaft 20. The shaft 20, which can be a solid or hollow elongated member, may be adapted to operatively engage the grip 40 at the end proximal to the user, and the shock-absorbing assembly 60, and/or implement 4, at the end distal to the user. The shaft 20 can be substantially straight, curved, or consisting of various angles in its lengthwise direction, and consist of a cross-sectional shape that is partially, or entirely, round, oval, square, rectangular or the like. In some embodiments, the shaft 20 may comprise one or more sections such that one of the one or more sections telescopes into another of the one or more sections.
With reference to
In still other embodiments, shown in
In one embodiment, the compression device 68 is a spring 69, such as a die spring, a heavy spring, or other spring selected by a person of skill in the art The spring 69 may have a diameter which permits the bolt 62 to pass through the spring 69 before mating with the nut 72. In other embodiments, the compression device 68 may be a hydraulic, pneumatic, gas shock, or coilover type shock absorber.
In these configurations, when the implement 4 is assembled onto the shock-absorbing assembly 60 and shaft 20 it is situated in a resting position RP, until impact forces F caused by impact of the implement 4 onto the workpiece cause the implement 4 to travel temporarily into a working position WP, defined generally as a position that is more proximal to the user than when the implement 4 is in a resting position RP, by virtue of movement of the compression device 68. The travel of the implement 4 relative to the handle 10—from a resting position RP to the working position WP, and back to the resting position RP as impact forces are absorbed—dampens the impact forces that would otherwise be transmitted to the user, thereby permitting the user to manipulate the hand tool 1 with greater comfort.
In various embodiments of the invention the distance the implement 4 travels from the resting position RP to the working position WP can vary according to user preferences. In one embodiment, the implement 4 travels approximately one quarter (¼) of an inch between its resting position RP and working position WP. In other embodiments, which might be characterized as further softening impact forces, the implement 4 moves approximately one (1) inch between its resting position RP and working position WP. In still other embodiments, the implement 4 may travel between one quarter (¼) inch and one (1) inch, or between one (1) inch and two (2) inches, or greater than two (2) inches between the resting position RP and working position WP.
In embodiments of the invention the distance the implement 4 is configured to travel between a resting position RP and working position WP can be changed by adjusting the position of the nut 72 relative to the bolt 62. For example, tightening the bolt 62 into the nut 72 secured within the shaft 20 compresses the spring 68 to a point where the implement 4 travels less distance between its resting position RP and its working position WP when confronted with impact forces. Similarly, as shown in
It may also be a feature of the invention that the implement 4 is resistant to the torsional forces caused by impact with the workpiece. In short, unless the shock-absorbing assembly 60 is configured to move the implement 4 between the resting position RP and working position WP in a substantially reciprocating path along the longitudinal axis of the handle 10, then torsional rotation TR of the implement 4 relative to the shaft 20 can cause either damage or ineffective and imprecise operation of the hand tool 1.
To prevent unwanted torsional movement, in some embodiments the shaft 20 has a distal end DE with a shape corresponding to the housing 66 of the shock-absorbing assembly 60. In some embodiments, the housing 66 is fixedly engaged to the implement 4. In the embodiment shown in
In some embodiments, the distal end DE of the shaft is of a shape different than the rest of the shaft 20; by way of non-limiting example, shown in
It should be recognized that the present invention is not limited to the exemplary hand tool handle 10 as shown. The configuration described herein and the particulars thereof can be readily applied to a variety of tools and applications. It is therefore understood that the above-described embodiments are illustrative of only a few of the possible specific embodiments which can represent applications of the invention. Numerous and varied other arrangements can be made by those skilled in the art without departing from the spirit and scope of the invention.
This application claims priority from U.S. Provisional Patent Application No. 62/421,574 which was filed on Nov. 14, 2016.
Number | Date | Country | |
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62421574 | Nov 2016 | US |