Aspects of the present invention deal with crossbows, and in particular deal with trigger assemblies for use in crossbows.
Crossbows have been used for centuries for both hunting and recreation. They are typically characterized by horizontal limbs mounted on a stock with a bowstring that is drawn to store energy that is transferred to a bolt upon firing. The bowstring is held in a string catch that holds the bowstring until the user is ready to fire. When the user is ready to shoot the bolt, the user pulls a trigger. Upon pulling the trigger, a series of interactions occurs between components of a trigger assembly, allowing the bowstring to be released from the string catch and allowing transfer of the energy stored in the bowstring to the bolt.
There are several different designs of crossbows. A recurve crossbow has a bowstring attached directly to limbs that extend from the body of the crossbow. When the bowstring is drawn, the limbs deflect and store potential energy that is transferred to the bowstring and a loaded arrow when the crossbow is fired. A compound crossbow has a set of wheels or cams attached to its limbs. A cabling system attached to the wheels or cams is used to bend the limbs as the bowstring is drawn.
Certain embodiments deal with a trigger assembly used in a crossbow. The trigger assembly includes a trigger mechanism, a pivot beam, a cable catch, and may include a safety mechanism. The cable catch is designed so that the trigger and pivot beam can remain in a non-firing position and do not need to move while the crossbow is cocked. The design of the trigger assembly may also allow a user to cock the crossbow while the safety mechanism is either engaged or disengaged.
A floating sear is attached to the cable catch and interacts with the pivot beam. In an uncocked position, the floating sear sits above the pivot beam; however, upon cocking the bow, the cable catch rotates and the floating sear slides past the pivot beam. A spring biases the floating sear to rotate downward upon gaining clearance from the pivot beam so that the back surface of the floating sear pivots downward to abut against the front surface of the pivot beam. Contact between the floating sear and the pivot beam maintains the trigger assembly in a loaded position.
To fire the crossbow, a user pulls a trigger, causing the trigger to rotate and moving a trigger roller to contact the pivot beam and to rotate the pivot beam. This rotation causes the front surface of the pivot beam to drop and lose contact with the floating sear. With clearance between the pivot beam and the floating sear, the cable catch is free to rotate and release a bowstring held within the cable catch.
Certain embodiments include a safety mechanism that includes a sliding safety bar with an opening. When the safety mechanism is disengaged, the safety bar is in a position where the opening is aligned with a safety pin mounted between the safety bar and the pivot beam. When the pivot beam rotates upon a user pulling the trigger, the safety pin is able to move into the opening in the safety bar. When the safety mechanism is engaged, the opening in the safety bar is not aligned with the safety pin. In this situation, if a user tries to pull the trigger, the safety pin is blocked and unable to move and thus the pivot beam is prevented from rotating.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
Certain embodiments shown in
In certain embodiments, when cocking the crossbow, the cable contacts a safety bar, pushing the safety bar backward into an engaged position. Thus, the safety mechanism is automatically engaged when a cable is loaded into the cocked position. The safety bar overlies a safety pin and the bar prevents the safety pin from moving, which in turn prevents the pivoting beam from pivoting. To disengage the safety, the user pushes the safety bar slightly forward, for example using the thumb of the hand adjacent the trigger, in the direction of firing. In the disengaged position, a hole in the safety bar is positioned over the safety pin and allows the safety pin to move upward, allowing the pivoting beam to pivot.
When a user pulls the trigger, a roller on the trigger mechanism contacts the pivot beam and urges the beam to rotate clockwise (from the perspective of
The floating sear setup described above allows the cable catch to pivot during loading without having to move the pivoting beam. This allows the crossbow to be loaded without having to move the trigger or the pivot beam into a firing position.
A sear or pivot beam 50 is positioned directly above trigger mechanism 20 and includes a rearward portion 52, a medial portion 54, and a forward portion 56. Contact member 28 generally contacts the bottom surface of rearward portion 52. The bottom surface of rearward portion 52 angles upward, providing a surface on which contact member 28 may roll when trigger mechanism 20 and pivot beam 50 both rotate. Medial portion 54 of pivot beam 50 forms a level surface adjacent a safety pin 58. Pivot beam 50 may pivot or rotate with respect to housing 14 on an attachment point to housing 14 at pivot 59.
Cable catch 40 is rotatably attached to housing 14 at a pivot point 41 and biased to rotate clockwise, in a forward direction. Cable catch 40 is shaped so that its top portion is able to retain the bowstring cable of a crossbow. The upper portion of cable catch 40 has two sets of prongs, rearward prongs 42, 44 and forward prongs 46, 48. A slot-like top opening 43 provides spacing between prong 42 and prong 44 and also provides spacing between prong 46 and prong 48. In the embodiment shown, the prongs are positioned so the upper portion of cable catch 40 has a substantially U-shaped channel between rearward prongs 42, 44 and forward prongs 46, 48 from a side view.
The bottom portion of cable catch 40 forms a slot-like bottom opening 45 between two side pieces. A floating sear 70 is rotatably mounted in opening 45 between the side pieces at sear pivot 74. Floating sear 70 translates with cable catch 40 as cable catch 40 rotates around pivot point 41. Sear pivot 74 allows floating sear 70 to also rotate with respect to cable catch 40. A stop 49 within housing 14 limits the clockwise rotation of cable catch 40 and floating sear 70.
Safety mechanism 60 includes a safety bar 62 that slides horizontally within trigger assembly 10. A safety switch 64 is positioned at the rearward end of safety bar 62. Visible in
A detent 78 is positioned underneath safety bar 62. Detent 78, for example, may be a spring-loaded, protruding ball bearing. Detent 78 engages with notches on the underside of safety bar 62. These notches are positioned at the forward and rearward limits of the movement of safety bar 62 with respect to detent 78. Detent 78 may be positioned to engage a corresponding notch to urge safety mechanism 60 to remain in either in an engaged or disengaged position.
For some embodiments, when trigger assembly 10 is in an uncocked position, as shown in
Trigger assembly 10 also includes an anti-dry fire lever 80 positioned so that when a bolt is not loaded in the crossbow, an end of lever 80 is in the forward end of opening 43. Lever 80 is attached to housing 14 at pivot 81, so that it may rotate with respect to housing 14. The anti-dry fire lever is engaged when lever 80 is positioned as shown in
Also, as cable catch 40 rotates, bowstring 8 contacts forward portion 68 of safety bar 62 between prongs 42, 44, forcing safety bar 62 to slide rearward and automatically engaging safety mechanism 60. As safety bar 62 slides rearward, safety opening 66 slides past safety pin 58, so that opening 66 and pin 58 are no longer aligned. In this position, safety mechanism 60 is engaged, as the lack of clearance between opening 66 and pin 58 will not allow pivot beam 50 to rotate if trigger 22 is pulled.
In other embodiments, the crossbow may be cocked while the safety is already set in the engaged position. For example, safety bar 62 can be manually slid rearward until opening 66 is no longer positioned above safety pin 58. The rotation of cable catch 40 while it is being cocked does not affect the position of pivot beam 50, so safety pin 58 does not move during the cocking process. This provides the advantage of allowing the user to cock the crossbow while safety mechanism 60 is engaged.
Due to the ability of floating sear 70 to rotate, pivot beam 50 is able to remain stationary throughout the cocking process. Because pivot beam 50 does not rotate as cable catch 40 is moved into the cocked position, trigger mechanism 20 also remains stationary throughout the cocking process. This feature allows trigger mechanism 20 and pivot beam 50 to remain in a non-firing position while the cable 8 is loaded into cable catch 40.
The clockwise rotation of pivot beam 50 forces safety pin 58 to move upward. As long as safety mechanism 60 is in the disengaged position, the movement of safety pin 58 is unconstrained and pin 58 enters opening 66. The forward portion 56 of pivot beam 50 moves downward as pivot beam 50 rotates, eventually providing clearance between forward portion 56 and floating sear 70. Once there is clearance and floating sear 70 disengages from forward portion 56, cable catch 40 rotates clockwise. The clockwise rotation of cable catch 40 releases bowstring 8 and, in turn, fires bolt 95.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
This application claims the benefit of U.S. Provisional Application No. 62/067,679 filed Oct. 23, 2014, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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62067679 | Oct 2014 | US |