US20080072887A1

US20080072887A1 - Limb for compound archery bow

Info

Publication number: US20080072887A1
Application number: US11/533,783
Authority: US
Inventors: Kyung-Rae Park
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-09-21
Filing date: 2006-09-21
Publication date: 2008-03-27

Abstract

Disclosed herein is a limb for a compound archery bow, comprising a core and a thin composite material completely surrounding the core. The core is made from synthetic foam or wood and the thin composite material is made from carbon fiber, a glass fiber, or a combination thereof. With such a structure, the compound archery bow has excellent impact absorption ability and high torsional strength, thereby achieving an increase in shooting speed.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates, in general, to a limb for an archery bow and, more particularly, to a limb for a compound archery bow, which is comprised of a core that is completely surrounded by carbon fiber or glass fiber so that it is light and durable and has high impact absorption.
2. Description of the Related Art
In order to better understand the background of the invention, conventional compound archery bows are described with reference to FIGS. 1 and 2. As shown in FIG. 2, a conventional compound archery bow comprises a handle 1 generally made from aluminum, a pair of upper bow limbs 2 and 3 detachably coupled to the upper portion of the handle 1, a pair of lower bow limbs detachably coupled to the lower portion of the handle 1, and a bowstring 6 coupled at both ends thereof to the limbs. FIG. 1 shows an early model of a compound archery bow. As illustrated in FIG. 1, each of the limbs of this conventional compound archery bow is a flat plate with bifurcate ends between which an eccentric wheel 4 is installed.
The upper and the lower eccentric wheel 4 rotate on their respective eccentric axes and are connected to each other by a cable 5 installed therebetween.
Whenever an archer shoots an arrow using the early model of archery bow, that is, whenever the bowstring is drawn and released, the eccentric wheel is stressed. Repetitive stress causes the bifurcate ends to split further.
With reference to FIGS. 3 and 4, cross sectional structures of such a conventional plate- or bar-type limb are shown. As seen, the limb is structured to have a core layer 7 with a carbon layer 8 and a glass fiber layer 9 laminated on either side thereof. Composed mainly of glass fiber, the limbs of the conventional archery bow are heavy and have insufficient impact absorption ability to ensure the durability of the archery bow.
In an archery bow, the structure of the limbs thereof is very important. Mechanically, it is the limbs that shoot arrows. The structure of the limbs directly influences the shooting speed and stability of the arrow and the resistance to vibrations occurring immediately after the shooting of the arrow. In this shooting mechanism, the weight and impact absorption ability of the limbs play a pivotal role.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made to solve the problem with the conventional limb, and an object of the present invention is to provide a limb for a compound archery bow, impact absorption, torsional strength and shooting speed of which are greatly improved.
In order to satisfy the object, an aspect of the present invention provides a limb for a compound archery bow, comprising a core completely surrounded by a thin composite material selected from a group consisting of a glass fiber, a carbon fiber, and a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIGS. 1 and 2 are perspective views showing conventional compound archery bows;

FIGS. 3 and 4 are enlarged cross-sectional partial perspective views respectively showing plate-type and bar-type limbs of conventional compound archery bows;

FIGS. 5, 7, 9 and 11 are enlarged cross-sectional partial perspective views showing plate-type limbs of compound archery bows in accordance with first to fourth embodiments of the present invention, respectively; and

FIGS. 6, 8, 10 and 12 are enlarged cross-sectional partial perspective views showing bar-type limbs of compound archery bows in accordance with first to fourth embodiments of the present invention, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Below, a detailed description will be given of the present invention in conjunction with embodiments illustrated in the accompanying drawings.
In accordance with an embodiment of the present invention, provided is a limb for a compound archery bow, which comprises a core made of wood or foam completely surrounded by a thin composite material selected from among carbon fiber, glass fiber and a combination thereof.
With reference to FIGS. 5 and 6, cross sectional partial perspective views show respective plate-type and bar- type limbs 100, 200 according to a first embodiment of the present invention. In this embodiment, the limb 100, 200 is comprised of a core 110, 210 completely surrounded by a carbon fiber layer 120, 220.
With reference to FIGS. 7 and 8, plate-type and bar- type limbs 100, 200 in accordance with a second embodiment of the present invention are respectively shown in cross sectional partial perspective views. In this embodiment, the limb 100, 200 is composed of a core 110, 210 completely surrounded by a glass fiber layer 130, 230.
FIGS. 9 and 10 show plate-type and bar- type limbs 100, 200, respectively, according to a third embodiment of the present invention in cross sectional partial perspective views. As shown in these views, the limb 100, 200 according to the third embodiment of the present invention is composed of a core 110, 210 completely surrounded by a carbon fiber layer 120, 220 and a glass fiber layer 130, 230 in that order.
FIGS. 11 and 12 are cross sectional partial perspective views respectively showing plate-type and bar- type limbs 100, 200 in accordance with a fourth embodiment of the present invention. In this embodiment, the limb 100, 200 is composed of a core 110, 210 completely surrounded by a glass fiber layer 130, 230 and a carbon fiber layer 120, 220 in that order.
In accordance with the present invention, the core 110, 210 is preferably made from synthetic foam or wood. It is preferable that the carbon fiber layer 120, 220 and the glass fiber layer 130, 230 each have a thickness of 0.5 mm or greater.
As described hereinbefore, provided is a limb of a compound archery bow, which comprises a core 110, 210 made from foam or wood with a carbon fiber layer 120, 220 and/or a glass fiber layer 130, 230 completely surrounding the core 110, 220.A compound archery bow having such a structure has excellent impact absorption ability and high torsional strength, thereby achieving increased shooting speed.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible. Accordingly, the modifications, additions and substitutions should be understood as falling within the scope and spirit of the invention.

Claims

1. A limb for a compound archery bow, comprising a core and a thin composite material completely surrounding the core.

2. The limb according to claim 1, wherein the thin composite material is selected from the group consisting of a carbon fiber layer and a glass fiber layer.

3. The limb according to claim 1, wherein the thin composite material has a bilayer structure comprising a carbon fiber layer and a glass fiber layer, with the carbon fiber layer in contact with the core.

4. The limb according to claim 1, wherein the thin composite material has a bilayer structure comprising a glass fiber layer and a carbon fiber layer, with the glass fiber layer in contact with the core.

5. The limb according to claim 1, wherein the limb, in cross section, is one of:

oval, and

circular.