Patent Application
20240133655
The present invention relates to a crossbow and, more particularly, to a high-speed arrow-shooting apparatus.
A conventional crossbow includes a barrel, a limb assembly transversely connected to a front section of the barrel, and a string formed with two ends tied to two ends of the limb assembly. An example of such conventional crossbows can be found in Taiwanese Patent 1582373.
However, the conventional crossbow is bulky because the limb assembly extends transversely relative to the barrel. It is troublesome for a user to carry or use the conventional crossbow, particularly in woods where space is limited.
There are attempts to overcome the above-mentioned problem. For example, US Patent Application Publication No. 2011/0303205 and U.S. Pat. Nos. 10,393,470, 8,671,923 and 4,169,456 disclose crossbows with foldable limb assemblies. The limb assemblies are folded when the crossbows are not in use. The limb assemblies are folded when the crossbows are in use.
When not in use, the crossbows with foldable limb assemblies are narrower than the conventional crossbows with the un-foldable limb assemblies. However, the crossbows with foldable limb assemblies are still bulky in use.
To overcome the above-mentioned problem, for example, U.S. patent Ser. No. 10/533,822 discloses several arrow-shooting apparatuses that occupy a smaller space than the crossbows with foldable limb assemblies in operation. The use of these arrow-shooting apparatuses is however not without any problems.
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In addition, the limbs 4 and 5 are made in one piece with the frame 1. The use of the arrow-shooting apparatus is limited.
Moreover, the string 10 extends in only one lap around the cams 6 and 8, thereby limiting acceleration of the string 10.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.
It is the primary objective of the present invention to provide a reliable high-speed arrow-shooting apparatus.
To achieve the foregoing objective, the high-speed arrow-shooting apparatus includes a barrel, a limb assembly, two fins, two wheels, a secondary-string pulley assembly, a primary string and two secondary strings. The limb assembly includes a riser, two limbs, two upper pulleys and two bars. The riser is connected to the barrel. Each of the limbs is connected to the riser at an end and substantially extends backward in parallel to the barrel. The upper pulleys are respectively connected to the limbs. The bars extend from the riser respectively below the limbs. The fins are connected to the barrel respectively below the bars. Each of the axles is connected to a corresponding one of the bars at an end and connected to a corresponding one of the fins at another end. The wheels are respectively supported on the axles. Each of the wheels includes a flat body, a rod, a primary-string stem and a secondary-string stem. The rod coaxially extends from the flat body. A diameter of the rod is smaller than a diameter of the flat body. The stems extend from the flat body. The secondary-string pulley assembly includes an axle and two lower pulleys. The axle is transversely connected to the barrel. The lower pulleys are supported on the axle respectively below the upper pulleys. Each terminal section of the primary string extends around a corresponding one of the wheels and is tied to the primary-string stem of the corresponding wheel. A middle section of the primary string extends between the wheels over the barrel. Each of the secondary strings is tied to the secondary-string stem of a corresponding one of the wheels at an end and tied to the riser at another end, and extends around the rod of a corresponding one of the wheels, a corresponding one of the lower pulleys, and a corresponding one of the upper pulleys.
Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.
The present invention will be described via detailed illustration of two embodiments referring to the drawings wherein:
Referring to
The barrel 10 is an elongated element. A stock 11 is connected to a rear end of the barrel 10. A cocking stirrup (not numbered) is connected to a front end of the barrel 10. A handle 12 is connected to a lower portion of the barrel 10 so that the handle 12 is located in front of the stock 11. A trigger 13 is pivotally connected to the barrel 10 so that the trigger 13 is located in front of the handle 12. These elements are conventional and will not be described in detail.
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A middle portion of the riser 21 is connected to the front section of the barrel 10. Two lateral portions of the riser 21 are located on two opposite of the barrel 10.
The first limb 22 is formed with a front section connected to the first lateral portion of the riser 21. The first limb 22 extends on a first side of the barrel 10 so that they are substantially in parallel to each other. A first pulley 221 is connected to a rear section of the first limb 22.
Similarly, the second limb 23 is formed with a front section connected to the second lateral portion of the riser 21. The second limb 23 extends on a second side of the barrel 10 so that they are substantially in parallel to each other. A second pulley 231 is connected to a rear section of the second limb 23.
The first stem 24 is connected to the first lateral portion of the riser 21. The second stem 25 is connected to the second lateral portion of the riser 21. The first and second stems 24 and 25 can be made in one piece with the riser 21.
The first bar 26 extends rearward from the first lateral portion of the riser 21. The second bar 27 extends rearward from the second lateral portion of the riser 21. The first and second bars 26 and 27 extends away from the barrel 10 below the first and second limbs 22 and 23.
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In another embodiment, the receptacle 33 can be omitted. Accordingly, the first and second fins 31 and 32 are made independent of each other and then connected to two opposite sides of the barrel 10.
A pivot 34 is located between and connected to the first bar 26 and the first fin 31. Another pivot 34 is located between and connected to the second bar 27 and the second fin 32. Each of the pivots 34 is inserted in an aperture (not numbered) made in a corresponding one of the compound wheels 40.
Referring to
The flat body 41 consists of a semi-circular portion 411 and a circular portion 412. The semi-circular portion 411 and the circular portion 412 are located side by side and made in one piece. The periphery of the semi-circular portion 411 is smaller than the periphery of the circular portion 412. The helical groove 42 extends in the periphery of the semi-circular portion 411 and the periphery of the circular portion 412.
The recess 43 is made in a lower face of the circular portion 412. The recess 43 is in communication with a cutout (not numbered) made in the periphery of the circular portion 412.
The primary-string stem 44 is located in the recess 43, and so is the secondary-string stem 45. The secondary-string stem 45 is located lower than the primary-string stem 44.
The threaded rod 46 extends from a center of the lower face of the circular portion 412. A helical groove 461 extends on the periphery of the threaded rod 46. The helical groove 461 includes an end (not numbered) aligned to the secondary-string stem 45. A diameter of the threaded rod 46 is much smaller than a diameter of the corresponding compound wheel 40.
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The axle 51 is transversely connected to the front section of the barrel 10, i.e., the axle 51 includes two terminal sections on two opposite sides of the barrel 10.
The third pulley 52 is supported on the first terminal section of the axle 51 below the first pulley 221. The fourth pulley 53 is supported on the second terminal section of the axle 51 below the second pulley 231.
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An end of the secondary string 72 is tied to the secondary-string stem 45 of a corresponding one of the compound wheels 40. Sequentially, the secondary string 72 extends around the helical rod 46 (in and along the helical groove 461) of the corresponding compound wheel 40, the fourth pulley 53, the second pulley 231 and the second terminal section of the axle 51. Another end of the secondary string 72 is tied to the second stem 25.
The structure of the high-speed arrow-shooting apparatus has been described above. The operation of the high-speed arrow-shoot apparatus will be described below.
Referring to
When the primary string 60 is released such as when the trigger 13 is pressed or pulled for example, the first limb 22 and the second limb 23 recover to allow the secondary strings 71 and 72 to return to the original positions. Accordingly, the compound wheels 40 are allowed to return to the original positions, thereby reeling in the primary string 60. Thus, the primary string 60 is allowed to shoot an arrow at high speed.
Advantageously, the secondary strings 71 and 72 respectively extend around the threaded rods 46 of the compound wheels 40, the third and fourth pulleys 52 and 53, the first and second pulleys 221 and 231, and the first and second terminal sections of the axle 51 so that a small range of the pivoting of the first and second limbs 22 and 23 causes a large range of the slinging of the primary string 60 to facilitate acceleration of an arrow (not shown) released from the primary string 60.
Preferably, a telescopic sight (not shown) is supported on the rear section of the barrel 10 in operation. The telescopic sight is not shieled by the limb assembly 20 due to the design and arrangement of the limb assembly 20.
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The present invention has been described via the illustration of the embodiments. Those skilled in the art can derive variations from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims.
