Double limb for arrow throwing device and arrow throwing device using the same

Abstract

The limb for an arrow throwing device, e.g. a bow or a crossbow, includes an upper portion, a lower portion, and an intermediate portion arranged between the upper portion and the lower portion. The upper portion and the lower portion are resilient. The intermediate portion is made non-resilient, capable of moving freely and not being deformed in conditions of load exerted on the limb during use thereof. The limb and the bow or the crossbow, featuring the limbs, can ensure a high speed of the arrow and a large stroke at small dimensions of the limb.

Claims

1. A bow comprising: two limbs, each limb having a first end and a second end; a bowstring; securing means for the bowstring arranged on said first ends of said limbs; and a handle on which said two limbs are installed with their second ends, wherein each limb comprises: an upper portion having one upper portion end and an opposite upper portion end; a lower portion having one lower portion end and an opposite lower portion end; and an intermediate portion arranged between the upper portion and the lower portion, wherein said one upper portion end connects to said intermediate portion, said opposite upper portion end forming a respective first end of each limb, wherein said one lower portion end connects to said intermediate portion, said opposite lower portion end forming a respective second end of each limb, wherein the upper portion and the lower portion are resilient, and wherein the intermediate portion is non-resilient, capable of moving freely and being not deformed in conditions of load exerted on the limb during use thereof.

2. The bow according to claim 1, further comprising at least one cable and attachment means for said at least one cable being installed on each of the first ends.

3. The bow according to claim 1, wherein the upper portion, the intermediate portion and the lower portion of each of the limbs are made as a single member.

4. The bow according to claim 1, wherein the upper portion, the intermediate portion and the lower portion of each of the limbs are made as separate elements connected therebetween.

5. The bow according to claim 4, wherein for each of the limbs at least two portions selected from the upper portion, the intermediate portion and the lower portion are made of different materials.

6. The bow according to claim 4, wherein for each of the limbs the upper portion, the intermediate portion and the lower portion are connected therebetween with the possibility of being separated.

7. The bow according to claim 1, wherein for each of the limbs resilience of the upper portion differs from resilience of the lower portion.

8. A crossbow comprising: two limbs, each limb having a first end and a second end; a bowstring; securing means for the bowstring arranged on said first ends of said limbs; and a body on which said two limbs are installed with their second ends, wherein each limb comprises: an upper portion having one upper portion end and an opposite upper portion end; a lower portion having one lower portion end and an opposite lower portion end; and an intermediate portion arranged between the upper portion and the lower portion, wherein said one upper portion end connects to said intermediate portion, said opposite upper portion end forming a respective first end of each limb, wherein said one lower portion end connects to said intermediate portion, said opposite lower portion end forming a respective second end of each limb, wherein the upper portion and the lower portion are resilient, and wherein the intermediate portion is non-resilient, capable of moving freely and being not deformed in conditions of load exerted on the limb during use thereof.

9. The crossbow according to claim 8, further comprising at least one cable and attachment means for said at least one cable being installed on each of the first ends.

10. The crossbow according to claim 8, wherein the upper portion, the intermediate portion and the lower portion of each of the limbs are made as a single member.

11. The crossbow according to claim 8, wherein the upper portion, the intermediate portion and the lower portion of each of the limbs are made as separate elements connected therebetween.

12. The crossbow according to claim 11, wherein for each of the limbs at least two portions selected from the upper portion, the intermediate portion and the lower portion are made of different materials.

13. The crossbow according to claim 11, wherein for each of the limbs the upper portion, the intermediate portion and the lower portion are connected therebetween with the possibility of being separated.

14. The crossbow according to claim 8, wherein for each of the limbs resilience of the upper portion differs from that of the lower portion.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 shows perspective views of embodiments of a curved (extending in different directions) limb according to the invention.

(2) FIG. 2 shows perspective and side schematic views of embodiments of a straight (unidirectional) limb according to the invention.

(3) FIG. 3 shows perspective views of embodiments of a bow according to the invention.

(4) FIG. 4 shows top plan view of an embodiment of a crossbow with straight (unidirectional) limbs.

(5) FIG. 5 shows upper and lower perspective views of embodiments of a crossbow with curved (extending in different directions) limbs.

DETAILED DESCRIPTION OF THE INVENTION

(6) A limb 1 according to the invention comprises an upper portion 2, an intermediate portion 3 and a lower portion 4. At an end 5 of the lower portion 4 connecting means 7 for connecting to an arrow throwing devicea bow 8.1 or a crossbow 8.2can be attached. A bowstring 10 is secured directly to a free end 6 of the upper portion 2 (FIGS. 3a, 3b, 4) or with the use of securing means 11 for securing the bowstring 10, e.g., a block (FIGS. 3c, 5a, 5b).

(7) The upper portion 2 and the lower portion 4 of the limb 1 are made resilient, so, when the bowstring 10 is being drawn, said portions 2, 4 are bended, i.e. change their shape, and when the bowstring 10 is released, said portions 2, 4 return to their initial positions, i.e. take the initial shape. The intermediate portion 3 is not deformed, i.e. does not change its shape when using the limb, and in this sense the intermediate portion 3 is non-resilient.

(8) The invariable shape, lack of deformation in the intermediate portion 3 means that the intermediate portion 3 is not involved in energy accumulation when the bowstring 10 is being drawn and in subsequent transfer of the accumulated energy to an arrow when the bowstring 10 is released. Energy is accumulated and transferred only due to bending of the upper portion 2 and the lower portion 4 of the limb 1, the limb 1 being attached to the arrow throwing device only via the end 5 of the lower portion 4, and the bowstring 10 is secured to the opposite end of the limb 1, namely to the free end 6 of the upper portion 2, either directly or via the securing means 11. When drawing the bowstring 10 the bend occurred practically along the whole length of the limb 1, except for the region where the intermediate portion 2 is arranged, enables to make draw of the bowstring 10 more smooth and simple with large amplitude, which ensures a high initial speed of the arrow. The most loaded portion of the limb 1, namely the intermediate portion 2, is made non-resilient, i.e. not bending, not changing its shape when the bowstring 10 is being drawn, and, consequently, it is not subjected to high wear during operation of the limb 1.

(9) The upper portion 2, the intermediate portion 3 and the lower portion 4 of the limb 1 may be made as a single element, as shown in FIG. 1a. In this case, in order to ensure non-resilient properties of the intermediate portion 3 during operation of the limb 1, the intermediate portion 3 is made, for example, with a cross-section that is greater than cross-sections of the upper portion 2 and the lower portion 4. One with ordinary skill in the art will understand how should relate the cross-sections of the upper portion 2, intermediate portion 3 and the lower portion 4 of the limb 1 in order to make the intermediate portion 3 not changing the shape thereof during conventional use of the limb in the bow 8.1 or the crossbow 8.2.

(10) Alternatively, the upper portion 2 and the lower portion 4 of the limb 1 may be made as individual members connected through the intermediate portion 2, as shown in FIG. 1b. In this case non-resilient properties of the intermediate portion 3 may be provided not only due to increased cross-section, but due to, for example, use of another material which, at typical loads exerted on the limb 1, allows the intermediate portion 3 keeping the shape thereof. It should be noted that in this embodiment the intermediate portion 3 may be also an individual member, or may form a single member either with the upper portion 2 or the lower portion 4.

(11) The limb 1 according to the invention may be not only curved, or extending in different directions (the upper portion 2 and the lower portion 4 of the limb 1 are arranged at an angle to each other even in complete absence of action from the bowstring 10), as shown in FIGS. 1a, 1b, but also essentially straight (in complete absence of action from the bowstring 10), or unidirectional, as shown in FIGS. 2a, 2b, 2c. In the latter case, the upper portion 2, the intermediate portion 3 and the lower portion 4 are arranged nearly along one line. The condition for resilience of the intermediate portion 2 is still valid, namely, the intermediate portion 2 should be non-resilient under load in the conventional operation mode of the limb 1. The shapes of the upper portion 2, the intermediate portion 3 and the lower portion 4 of the limb 1 may be different.

(12) The upper portion 2 and/or the lower portion 4 of the limb 1 may be made as one-piece members or may consist of several elements. For example, as shown in FIG. 3a, the upper portion 2 and the lower portion 4 of the limb 1 are made each as a one-piece member. FIG. 3b shows an embodiment wherein the upper portion 2 is made as a one-piece member, and the lower portion 4 consists of two elements. FIGS. 3c, 5a, 5b show another embodiment wherein the upper portion 2 consists of two elements, and the lower portion 4 is made as a single member. It is also possible to make the upper portion 2 and the lower portion 4 consisting of two elements each.

(13) FIGS. 3a, 3b, 3c show embodiments of a bow according to this invention. The limbs 1 are attached to a handle 9.1 with the ends 5 of the lower portion 4, and the bowstring 10 is secured to the ends 6 of the upper portion 2. The bowstring 10 may be secured to the ends 6 in the way shown in FIG. 3a, 3b, or via the securing means 11 made, e.g., as a block shown in FIG. 3c. If the securing means 11 is used, the bow 8.1 may also comprise one or more cables 12.

(14) FIG. 4 shows an embodiment of a crossbow according to the invention, wherein the lower portion 4 of the limb is attached to a body 9.2 of the crossbow, and the bowstring 10 is secured to the ends 6 of the upper limb 2 directly. Alternatively, in the embodiments of the crossbow according to the invention, as shown in FIGS. 5a, 5b, the bowstring 10 is secured to the ends 6 of the upper limb 2 via the securing means 11.

(15) Strengthening of the limb 1 in the region of the intermediate portion 3 by making the intermediate portion 3 non-resilient in conventional operation of the limb 1 enables to use practically the whole length of the limb 1 for accumulating energy and to ensure stability of the most loaded intermediate portion 3 at various loads. This principle may be applied to the limbs 1 of any shape, both unidirectional and extending in different directions.

(16) The proposed limb and the bow or the crossbow featuring said limbs ensure a high speed of the arrow and a large stroke at small dimensions of the limb.