Patent Application
20070243959
A broadhead constructed in accordance with an embodiment of the invention is illustrated in
With reference to the figures, the components of the broadhead will now be described in further detail. Referring specifically to
In the embodiment shown, the ferrule 20 is monolithic structure. Therefore, all components and structures associated with the ferrule can be integral with the ferrule and contiguous with other components of the ferrule. As will be discussed below, this monolithic configuration can be achieved via metal injection molding, powder injection molding or by other casting processes.
Referring further to
The blade slot 30, shown in
The monolithic ferrule 20 can be constructed entirely from metal. Optionally, this metal is substantially rigid and non-deformable. Accordingly, the land 34 and inclined surface 35 can be non-deformable so that when the blade 40 is installed in the blade slot 30 and wedged against and engages these two components of the blade slot 30, these components do not deform. Slight scratching and/or marring of these components is not considered deforming.
With reference to
At the forward portion 41 of the blade 40, the blade includes a locking member 42. This locking member is generally substantially triangularly shaped. Of course, the forward most portion of this locking member 42 can be pointed, rounded or cut off at an angle relative to the land edge 48 as desired. Optionally, the forward portion of the blade includes a slot engagement surface 47 that is inclined relative to the land edge. The angle of inclination of this slot engagement surface 47 can be similar to that described above in connection with the inclined surface 35. Indeed, the locking member 42 can be correspondingly shaped and include the same dimensions as the locking pocket 32.
As shown in
When the blade 40 is installed in the blade slot 30, the forward portion 41 of the blade is trapped in the ferrule 20 via the locking member 42 engaging the pocket 32. Specifically, when the ferrule is installed on an arrow and threaded or otherwise tightened relative to the arrow 100 or arrow insert 101, the blade 40 is pressed forward so that the locking member 42 wedges within the pocket 32. More specifically, the slot engaging surface 47 frictionally engages the inclined surface 35 of the blade slot 30. Likewise, the land edge 48 frictionally engages the land 34 of the blade slot 30. Again, where the ferrule 20 is constructed from an non-deformable material, this engagement does not cause deformation of the inclined surface 35 or the land 34.
As shown in
A method of making a broadhead 10 will now be described. This method includes manufacturing the ferrule, and optionally the replacement blades from a metal, such as a steel alloy, using a metal injection molding (“MIM”) or powder injection molding (“PIM”) process. Features of the ferrule such as the blade slot 30 defining the interlocking pocket 32, can be formed in a finished manner using the MIM or PIM process.
In general, the metal injection molding process includes injection molding a mixture of powdered metal and binder into a mold configured in the shape of the ferrule. The ferrule mold can define a blade slot, the blade slot being bounded by a land and an inclined surface that overhangs a portion of the land as described above. It will be appreciated the other features of the broadhead described above can be included in the ferrule mold as desired.
After the ferrule is metal injection molded, it undergoes a debinding step and a subsequent sintering operation, which is a form of heat treatment that bonds the particles and increases the density and strength of the finished ferrule. A more detailed description of the MIM process and the formation of broadhead components such as ferrules and blades is included in U.S. Pat. No. 6,749,801 to Louis Grace, Jr. et al, which is hereby incorporated by reference, and U.S. Pat. No. 6,290,903 to Louis Grace, Jr. et al, which is also incorporated by reference.
With the ferrule metal injected molded or otherwise formed, the blade 40 is joined with the ferrule. As shown in
With the blade installed in the blade slot 30, the annular member 50 is positioned over the tab 49 of the blade to secure the rearward portion of the blade 43. The broadhead can be installed on an arrow by a user. As the broadhead is threaded into the arrow 100, the arrow insert 101 and/or the arrow and/or the retaining member 50 engages the blade 40 thereby urging the blade forward while drawing the ferrule 20 into the arrow insert or arrow shaft. Accordingly, the locking member 42 is lockingly wedged within the pocket 32 of the ferrule. By way of this wedging action, the forward portion of the blade frictionally engages the inclined surface 35 and the land 34, and traps the forward portion of the blade within the blade slot of the ferrule. Where the ferrule 20 is constructed from metal, the components of the blade 40 may scratch or slightly mar the blade slot, namely the land 34 and the inclined surface 35.
Optionally, the monolithic ferrule 20 and the blades 40 can be manufactured using other processes. For example, where the ferrule is manufactured from a light metal alloy, it can alternatively be formed via a casting process such as die-casting, investment casting or thixotropic molding.
The above descriptions are those of the preferred embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular.
This application claims benefit of U.S. provisional patent application 60/792,690 filed Apr. 18, 2006, which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60792690 | Apr 2006 | US |
