Projectile launching device with self-timing and without cam lean

Abstract

A projectile launching device includes self-timing without cam lean. The projectile launching device includes a riser, a rail, two energy storing components, (such as two limbs), two cams, a launch string, and least one cable. The ends of the launch string are attached to the two cams. Opposing ends of first and second cables are coupled to the rail. A mid-portion of the first and second cables are slidably engaged with the first and second cams, respectively. Alternatively, a single cable may replace the first and second cables. The two cams are preferably built as mirror images of each other at a centerline of the rail. The two cams include a launch string track, having identical, but mirrored, upper and lower cable tracks.

Claims

1. A projectile launching device without cam lean includes a rail, a riser, a first energy storing component, a second energy storing component, the riser is attached to the rail, one end of the first energy storing component is attached to a first end of the riser, one end of the second energy storing component is attached to a second end of the riser, comprising: a first cam is capable of being pivotally retained on the first energy storing component, said first cam includes a first launch string track, a first upper cable track, a first lower cable track and a first cable boss, said first upper cable track is located above said first launch string track, said first lower cable track is located below said first launch string track, said first cable boss extends from an edge of said first cam; a second cam is capable of being pivotally retained on the second energy storing component, said second cam includes a second launch string track, a second upper cable track, a second lower cable track and a second cable boss, said second upper cable track is located above said second launch string track, said second lower cable track is located below said second launch string track, said second cable boss extends from an edge of said second cam, wherein said first and second launch string tracks are capable of retaining a launch string; a first cable having one end coupled to said rail, said first cable is retained in said first upper cable track, said first cable passes through said first cam, said first cable is slidably engaged with said first cam boss, said first cable is retained in said first lower cable track, an opposing end of said first cable is attached to said rail; and a second cable having one end coupled to said rail, said second cable is retained in said second upper cable track, said second cable passes through said second cam, said second cable is slidably engaged with said second cam boss, said second cable is retained in said second lower cable track, an opposing end of said second cable is attached to said rail.

2. The projectile launching device without cam lean of claim 1 wherein: said first and second cables are substantially parallel to said launch string.

3. The projectile launching device without cam lean of claim 1 wherein: a first distance between said upper cable track and said launch string track is equal to a second distance between said lower cable track and said launch string track.

4. The projectile launching device without cam lean of claim 1, further comprising: a first upper cable post extends from a first side of the rail, above a plane of said first and second cams, a first lower cable post extends from the first side of the rail below said plane of said first and second cams.

5. The projectile launching device without cam lean of claim 1, further comprising: a second upper cable post extends from a second side of the rail, above a plane of said first and second cams, a second lower cable post extends from the second side of the rail below said plane of said first and second cams.

6. A projectile launching device without cam lean includes a rail, a riser, a first energy storing component, a second energy storing component, the riser is attached to the rail, one end of the first energy storing component is attached to a first end of the riser, one end of the second energy storing component is attached to a second end of the riser, comprising: a first cam is capable of being pivotally retained on the first energy storing component, said first cam includes a first launch string track, a first upper cable track, a first lower cable track and a first cable boss, said first upper cable track is located above said first launch string track, said first lower cable track is located below said first launch string track, said first cable boss extends from an edge of said first cam; a second cam is capable of being pivotally retained on the second energy storing component, said second cam includes a second launch string track, a second upper cable track, a second lower cable track and a second cable boss, said second upper cable track is located above said second launch string track, said second lower cable track is located below said second launch string track, said second cable boss extends from an edge of said second cam, wherein said first and second launch string tracks are capable of retaining a launch string; and a cable having one end coupled to said rail, said cable is retained in said first upper cable track, said cable passes through said first cam, said cable is slidably engaged with said first cam boss, said cable is retained in said first lower cable track, said cable extends across the rail, said cable is retained in said lower cable track, said cable passes through said second cam, said second cable is slidably engaged with said second cam boss, said cable is retained in said second upper cable track, an opposing end of said cable is attached to said rail.

7. The projectile launching device without cam lean of claim 6 wherein: said cable is substantially parallel to said launch string.

8. The projectile launching device without cam lean of claim 6 wherein: a first distance between said upper cable track and said launch string track is equal to a second distance between said lower cable track and said launch string track.

9. The projectile launching device without cam lean of claim 6, further comprising: a first upper cable post extends from a first side of the rail, above a plane of said first and second cams, a second upper cable post extends from a second side of the rail, above said plane of said first and second cams.

10. A projectile launching device without cam lean includes a rail, a riser, a first energy storing component, a second energy storing component, the riser is attached to the rail, one end of the first energy storing component is attached to a first end of the riser, one end of the second energy storing component is attached to a second end of the riser, comprising: a first cam is capable of being pivotally retained on the first energy storing component, said first cam includes a first launch string track, a first upper cable track, a first lower cable track and a first cable boss, said first upper cable track is located above said first launch string track, said first lower cable track is located below said first launch string track, said first cable boss extends from an edge of said first cam; a second cam is capable of being pivotally retained on the second energy storing component, said second cam includes a second launch string track, a second upper cable track, a second lower cable track and a second cable boss, said second upper cable track is located above said second launch string track, said second lower cable track is located below said second launch string track, said second cable boss extends from an edge of said second cam, wherein said first and second launch string tracks are capable of retaining a launch string; a first cable having one end coupled to said rail, said first cable is retained in said first upper cable track, said first cable passes through said first cam, said first cable is slidably engaged with said first cam boss, said first cable is retained in said first lower cable track, an opposing end of said first cable is attached to said rail, said first cable does not cross the rail; and a second cable having one end coupled to said rail, said second cable is retained in said second upper cable track, said second cable passes through said second cam, said second cable is slidably engaged with said second cam boss, said second cable is retained in said second lower cable track, an opposing end of said second cable is attached to said rail, said second cable does not cross the rail.

11. The projectile launching device without cam lean of claim 10 wherein: said first and second cables are substantially parallel to said launch string.

12. The projectile launching device without cam lean of claim 10 wherein: a first distance between said upper cable track and said launch string track is equal to a second distance between said lower cable track and said launch string track.

13. The projectile launching device without cam lean of claim 10, further comprising: a first upper cable post extends from a first side of the rail, above a plane of said first and second cams, a first lower cable post extends from the first side of the rail below said plane of said first and second cams.

14. The projectile launching device without cam lean of claim 10, further comprising: a second upper cable post extends from a second side of the rail, above a plane of said first and second cams, a second lower cable post extends from the second side of the rail below said plane of said first and second cams.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of a crossbow with no cam lean in accordance with the present invention.

(2) FIG. 2 is a top view of a crossbow with no cam lean, where the cable tracks are mostly round, and the launch string is at rest in accordance with the present invention.

(3) FIG. 3 is a partial bottom view of a crossbow with no cam lean, where the cable tacks are mostly round, and the launch string is at rest in accordance with the present invention.

(4) FIG. 4 is a partial top view of a crossbow with zero cam lean, where the cable track is not round, and the launch string is at rest in accordance with the present invention.

(5) FIG. 5 is a partial bottom view of a crossbow with zero cam lean, where the cable track is not round, and the launch string is at rest in accordance with the present invention.

(6) FIG. 6 is a partial top view of a crossbow with zero cam lean, where the cable track is mostly round, and the launch string is in a ready-to-fire position in accordance with the present invention.

(7) FIG. 7 is a partial bottom view of a crossbow with zero cam lean, where the cable track is mostly round, and the launch string is in a ready-to-fire position, in accordance with the present invention.

(8) FIG. 8 is a cut away view of a crossbow with zero cam lean, looking forward, just behind the cams, showing the launch string and routing of the cables, in accordance with the present invention.

(9) FIG. 9 is a front view of a crossbow with zero cam lean with a stirrup removed, looking at the front of the crossbow, showing the launch string and routing of the cables, in accordance with the present invention.

(10) FIG. 10 is a front view of a crossbow with zero cam lean with a stirrup removed, looking at the front of the crossbow, showing the launch string and routing of the single cable, in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(11) With reference now to the drawings, FIG. 1 shows a side view of a projectile launching device 1, which includes a operably releasable launch string housing 56 coupled to a rail 12. With reference to FIGS. 2-6, the projectile launching device 1 preferably includes a bow riser 10, a rail 12, a first limb 14, a second limb 16, a first cam 18, a second cam 20 and at least one launch string 22. The bow riser 10 may be joined with the rail 12 in any method known to join two pieces, as well as the rail 12 and the riser 10 being formed together as a single unit. A first end of the first limb 14 is coupled to a first end of the bow riser 10 and a first end of the second limb 16 is coupled to a second end of the bow riser 10. The first cam 18 is pivotally retained on an opposing end of the first limb 14 and the second cam 20 is pivotally retained on an opposing end of the second limb 16.

(12) The first cam 18 includes a first launch string track 19, a first cam upper cable track 40, a first cam launch string post 61, a first cam boss 34, and a first cam lower cable track 41. The second cam 20 includes a second launch string track 21, a second cam upper cable track 42, a second cam launch string post 63, a second cam boss 35, and a second cam lower cable track 43. The first and second cam bosses 34, 35 preferably have a round diameter. A first end of the launch string 22 is retained by the first cam launch string post 61, a portion of the span of the launch string 22 at least partially wraps the first cam 18 in the first cam launch string track 19, a portion of the span of the launch string 22 at least partially wraps the second cam 20 in the second cam launch string track 21, and a second end of the bowstring 22 is retained by the second cam launch string post 63.

(13) A first end of a first cable 44 is coupled to a first upper cable post 24, a segment of the first cable 44 before the center of the cable 44 partially engages the first cam upper cable track 40, the middle of the first cable partially wraps around the first cam cable boss 34, a segment of the first cable 44 after the center of the first cable 44 partially engages the first cam lower cable track 41, and the second end of the first cable 44 is coupled to the first lower cable post 25. The first cable 44 does not cross the rail 12. A first end of a second cable 46 is coupled to a second upper cable post 26, a segment of the second cable 46 before the center of the second cable 46 partially engages the second cam upper cable track 42, the middle of the second cable 46 partially wraps around the second cam cable boss 35, a segment of the second cable 46 after the center of the second cable 46 partially engages the second cam lower cable track 43, and the second end of the second cable 46 is coupled to a second lower cable post 27. The first and second upper cable posts 24, 26 are located above a horizontal plane of the first and second cams 18, 20. The first and second lower cable posts 25, 27 are located below a horizontal plane of the first and second cams 18, 20. The second cable 46 does not cross the rail 12.

(14) With reference to FIGS. 6-9, when the launch string 22 is drawn from an at rest position to a ready to fire position, the first cam 18 rotates in a first direction, and the second cam 20 rotates in a second direction. As the cams 18 and 20 rotate, the launch string 22 is unwound from the first and second launch string tracks 19 and 21. Simultaneously, the cables 44 and 46 wind into the upper 40 and 42 and lower 41 and 43 cable tracks of the first 18 and second 20 cams. When the launch string 22 has been drawn to the ready-to-fire position, it may be held in this the position by an operably releasable catch located in a housing 56. The first cable 44 is slidable relative to the first cam cable boss 34 and the second cable 46 is slidable relative to the second cam cable boss 35.

(15) With reference to FIG. 10, an alternate embodiment uses the launch string 22 and a single cable 45. A first end of the single cable 45 is attached to the first upper cable post 24, a span of the single cable 45 is retained on the first cam boss 34 of the first cam 18, crosses a center-line of the rail 12, is retained on the second cam boss 35 of the second cam 20, and a second end of the single cable 45 is attached to the second upper cable post 26. The single cable 45 replaces first and second cables 44, 46.

(16) It is preferable for both single and double cable designs that a vertical distance between the lower cable tracks 41, 43 and the string launch track 19, 21 be equal to a vertical distance between the upper cable tracks 40, 42 and the string launch track 19, 21. However, the projectile launching device 1 will function satisfactory without the above vertical distance conditions. It is also preferable that the cables 44, 45, 46 be parallel to the launch string 22. However, the projectile launching device 1 will function satisfactory without the parallel conditions.

(17) While the preferred embodiment of the invention has been illustrated and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.