Fletching alignment nut

• US 4,781,386 A
• Filed: 07/31/1987
• Issued: 11/01/1988
• Est. Priority Date: 07/31/1987
• Status: Expired due to Term

• Current Assignee: Sandra L. Armitage
• Original Assignee: George E. Armitage
• Inventors: Armitage, George E.
• Primary Examiner(s): Shapiro, Paul E.
• Application Number:
  US07/080,018
• Time in Patent Office: 459 Days
• Field of Search: 273/416, 273/419-423
• US Class Current: 473/584
• CPC Class Codes: F42B 6/02 Arrows; Crossbow bolts; Harpoons for hand-held spring or air guns

Abstract

An arrow which includes a broadhead having a tapered body with axial blade receiving slots formed therein and an axial aperture formed in the rearward end thereof, a point coupled to the forward end of the body, and blades removably received in the slots with their forward ends removably secured in position by the point and with their rearward ends extending rearwardly of the body. The arrow also includes a shaft having a nock at the rearward end therof, an axial aperture formed in the foward end thereof and fletching symmetrically arranged around its periphery adjacent to the nock equal in number to the number of blades. The arrow also includes an assembly coupling the broadhead and shaft. The assembly comprises a cylindrical stem having cylindrical surfaces formed on its forward and rearward ends coupled to the axial apertures in the rearward end of the broadhead and the forward end of the shaft and intermediate external threads therebetween. The assembly also includes a cylindrical cap having internal threads received on the intermediate threads whereby rotation of the cap with respect to the stem will adjust the axial position of the cap along the length of the stem allowing for the varying of the rotational position of the broadhead with respect to the shaft. The assembly yet further includes an adjusting washer positionable for correcting rotational non-symmetry of the arrow.

Claims

1. For use in association with an arrow broadhead having a blades symmetrically arranged around its periphery and an arrow shaft having fletching symmetrically secured around its periphery in number equal to the number of blades, apparatus for coupling a broadhead and a shaft comprising:

a cylindrical stem having first means formed at its forward end for coupling with the rearward end of a broadhead and having second means formed at its rearward end for coupling with the forward end of a shaft and having threads therebetween formed on the exterior surface of the stem; and

a cylindrical cap having internal threads received on the threads of the stem whereby rotation of the cap with respect to the stem will allow for the adjustment of the rotational position of a broadhead with respect to a shaft when coupled to the stem.

2. The apparatus as set forth in claim 1 and further including an adjustment washer having an internal aperture of a diameter for positioning over the stem adjacent to one end of the cap.

3. The apparatus as set forth in claim 2 wherein the adjustment washer has an internal diameter sufficiently greater than that portion of the stem upon which it is received to allow for its radial shifting to thereby correct for rotational non-symmetry.

4. The apparatus as set forth in claim 3 wherein the external diameter of the adjustment washer is less than the external diameter of the cap.

5. The apparatus as set forth in claim 2 wherein the cap has a forward abutment surface to limit the movement of a broadhead onto the stem and a rearward abutment surface to limit the movement of a shaft onto the stem.

6. The apparatus as set forth in claim 1 wherein one of the means includes a circumferential groove to receive a pin for restricting axial movement therebetween.

7. The apparatus as set forth in claim 6 wherein the groove is the first means.

8. The apparatus as set forth in claim 1 wherein the first and second means are threads of a different number of threads per inch so that the axial position of the cap with respect to the stem will determine the rotational orientation of a broadhead with respect to a shaft to allow for the axial alignment of their blades with their fletching.

9. An arrow including, in combination:

a broadhead having a tapered body with a plurality of axial blade receiving slots symmetrically formed around the periphery thereof and an axial aperture formed in the rearward end thereof, a point coupled to the forward end of the body, and blades removably received in the slots with their forward ends removably secured in position by the point and with their rearward ends extending rearwardly of the body;

a shaft having a nock at the rearward end thereof, an axial aperture formed in the forward end thereof and fletching symmetrically secured around its periphery adjacent to the nock equal in number to the number of blades; and

an assembly coupling the broadhead and shaft comprising a cylindrical stem having a cylindrical forward end coupled within the rearward end of the broadhead and having a cylindrical rearward end coupled within the forward end of the shaft and having intermediate external threads formed therebetween, the assembly also including a cylindrical cap having internal threads received on the intermediate threads of the stem whereby rotation of the cap with respect to the stem will move the cap along the length of the stem allowing for the varying the rotational position of the broadhead and shaft with respect to each other.

10. The arrow as set forth in claim 9 wherein the cap has a forward abutment surface for assisting in the retaining of the blades in their operative positions in the slots.

11. The arrow as set forth in claim 10 and further including an adjustment washer received over the stem and the rearward ends of the blades between the forward abutment surface of the cap and the rearward end of the body.

12. The arrow as set forth in claim 11 wherein the adjustment washer has an internal diameter sufficiently greater than the ends of the blades over which it is received to allow for its radial shifting to thereby correct for rotational non-symmetry.

13. The arrow as set forth in claim 12 wherein the external diameter of the adjustment washer is less than the external diameter of the cap.

14. The arrow as set forth in claim 11 wherein the cap is undercut at its forward end for receiving the rearward ends of the blades to preclude their radial movement out of the slot.

15. The arrow as set forth in claim 14 wherein the forward abutment surface of the cap provides an axial force with respect to the rearward ends of the blades to preclude their axial movement with respect to the slot.

16. The arrow as set forth in claim 9 wherein one of the ends of the stem includes threads and its associated axial aperture also includes threads received by the threads of the stem while the other of the ends of the stem includes a circumferential groove and its associated axial aperture includes a pin received within the groove to restrict axial movement therebetween.

17. The arrow as set forth in claim 16 wherein the groove and pin couple the shaft and the broadhead.

18. The arrow as set forth in claim 9 wherein the axial apertures and the ends of the stem are all threaded.

19. The arrow as set forth in claim 18 wherein the threads coupling the stem and broadhead are of a different pitch than the threads coupling the stem and shaft whereby the position of the cap with respect to the stem will determine the rotational orientation of the broadhead with respect to the shaft to allow for the axial alignment of their blades with their fletching.