US3625193A

US3625193A - Archery bow with variable bow-tensioning device

Info

Publication number: US3625193A
Application number: US39297A
Authority: US
Inventors: James R Palma
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-05-21
Filing date: 1970-05-21
Publication date: 1971-12-07
Anticipated expiration: 1988-12-07

Abstract

An archery bow provided with an internal cavity extending substantially along its entire length. A pair of longitudinally movable reinforcing members are disposed in the cavity for movement therein toward the ends of the bow which are drivingly connected by an actuator having a shaft extending outwardly of the bow to which is secured a knob for rotation of said actuator to move the reinforcing members in opposite directions to thereby adjustably vary the tension force of said bow and thereby vary the force necessary to bend the bow. The bow has a pointer that indicates on a scale the adjusted tension force developed in the bow.

Description

United States Patent Inventor James R. Palma 1502 Curry Road, Schenectady, N.Y. 12306 Appl. No. 39,297

Filed May 21, 1970 Patented Dec. 7, 1971 ARCHERY BOW WITH VARIABLE BOW- Primary Examiner-Richard C. Pinkham Assistant Examiner-William R. Browne Anomey- Settle and Oltman ABSTRACT: An archery bow provided with an internal cavity extending substantially along its entire length. A pair of longitudinally movable reinforcing members are disposed in the cavity for movement therein toward the ends of the bow which are drivingly connected by an actuator having a shaft extending outwardly of the bow to which is secured a knob for rotation of said actuator to move the reinforcing members in opposite directions to thereby adjustably vary the tension force of said bow and thereby vary the force necessary to bend the bow. The bow has a pointer that indicates on a scale the adjusted tension force developed in the bow.

ARCHERY BOW WITH VARIABLE BOW-TENSIONING DEVICE BACKGROUND OF THE INVENTION The present invention refers to archery bows for hunting or target shooting and more in particular to an archery bow having a tensioning device to vary the force required to bend the bow.

Archery bows are normally constructed to provide an elongated curvilinear body having a midportion of increased cross section and tapering towards opposite ends to terminate in tip portions which are interconnected by the bow string. The bow is usually made of a flexible material and the tapered configuration adds to the flexibility of the bow when the bow string is tensioned by the placement of an arrow on the string.

It is often required to vary the tension of the bow under certain hunting or target shooting conditions. Thus, under certain circumstances, bows of varying stiffnesses must be used to obtain the required arrow propelling force.

It is known to adjustably mount the bow string so that its position can be varied at the tip ends of the bow to thereby increase or decrease the effective length of the bow adding more stiffness to the bow as the string is moved towards the center of the bow and increasing the flexibility of the bow as the string is moved further outwardly towards the tip ends. However, this arrangement is unsatisfactory in that it foreshortens the arrow string and in that only a limited number of definite positions are available to vary the tension force required to bend the bow.

SUMMARY OF THE INVENTION The present invention provides an archery bow which is hollow substantially along its entire length. Slidable elongated reinforcing members are disposed within the bow for movement in opposite directions toward the bow ends to thereby vary the tension force required to bend the bow. The elongated reinforcing members are interconnected at the center of the bow by a rack and pinion mechanism operable from the outside of the bow. The pinion shaft on the outside of the bow is provided with a knob for rotation of the pinion and which has a pointer to cooperate with a scale or dial to indicate the adjusted tension force.

The tension device of the present invention provides infinite tension adjustment for an'archery bow by simply turning the knob on the outside of the bow to the desired position.

The device of the present invention will be best understood by reference to the following detailed description in connection with the appended drawings forming a part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate a preferred embodiment of the invention in which FIG. I is a longitudinal cross section through an archery bow embodying the device of the present invention;

FIG. 2 is a side elevation of the midportion of the archery bow shown in FIG. I;

FIG. 3 is an enlarged transverse cross section through the midportion of the bow in FIG. I showing the actuating mechanism more in detail; and

FIG. 4 is a transverse cross section through the archery bow as shown in FIG. I as seen along line 44 thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawings an archery bow constructed in accordance with the present invention is shown at comprising substantially identical

elongated body portions

12 and 14 which are shaped curvilinear and provide a substantially rigid midportion of increased cross section 16. From the handle or midportion I6 the bow limb members 12 and I4 are tapered in opposite directions towards the

tip portions

18 and 20 respectively. The tapered configuration adds to the flexibility of the bow and simultaneously uniformly distributes bending stresses along its length.

Each of the opposite body portions I2 and 14 is provided with a longitudinal cavity 22 extending from the midportion 16 16 toward the

ends

18 and 20 of the bow. It will be understood that, in an assembly, the identical body portions I2 and 14 of the bow will be laminated together along their solid cross sections so as to enclose the cavity 22.

A pair of tapered reinforcing

members

24 and 26 are disposed within the cavity 22. Each of the reinforcing

members

24 and 26 comprises an elongated plate which is tapered toward the tip portions I8 and 20 respectively. The reinforcing

members

24 and 26 are disposed such as to overlap at the midportion I6 of the bow. The overlapping ends of the reinforcing

members

24 and 26 are each provided with oppositely disposed

rack teeth

28 and 30 respectively which face each other.

The reinforcing

members

24 and 26 are biased towards each other at the midportion 16 by means of

springs

32 and 34, respectively, secured in the cavity 22 adjacent the sides of the

plates

24 and 26 opposite from the

rack teeth

28 and 30 respectively.

The reinforcing

members

24 and 26 are adapted to slide within the cavity 22 in opposite directions toward the tip ends of the bow or away therefrom towards the midportion. To accomplish this, a pinion 36 is rotatably disposed between the

rack teeth

28 and 30 of the reinforcing

members

24 and 26. The pinion 36 is supported on a pinion shaft 38 which inner end is joumaied within a boss portion 40 provided in the cavity 22 at the midportion 16 of the bow. The pinion shaft 38 extends outwardly of the bow at one side thereof at the midportion I6 and is provided outwardly with a knob 42 providing a handgrip for manual rotation of the pinion shaft 38. The knob 42 is provided with a pointer 44 which cooperates with an indicating means such as a scale or dial 46 provided on the outside of the midportion I6 of the bow. The dial 46 together with the pointer 44 indicates to the bow handler the respective adjusted position of the reinforcing

members

24 and 26 within the bow so as to be able to obtain a correct tension adjustment.

It will be understood that in operation tension adjustment of the bow I0 is accomplished by manipulation of the knob 42 on the outside of the bow. Rotation of the knob 42 in one direction causes longitudinal movement of the reinforcing

members

24 and 26 in opposite directions toward the

tip ends

18 and 20 of the bow l0 and rotation of the knob 42 in the opposite direction causes longitudinal movement of the reinforcing

members

24 and 26, again in opposite directions, toward the midportion 16. If the reinforcing

members

24 and 26 are moved outwardly toward the tip ends 18 and 20 the stiffness of the bow or the tension force required to bend the bow will be increased and, conversely, if the reinforcing

members

24 and 26 are moved towards each other, i.e. toward the midportion I6 of the how the stiffness of the bow will be decreased, requiring a lesser amount of tension force to bend the bow.

The reinforcing

members

24 and 26 are preferably made of spring steel having a desired stiffness against bending.

During assembly the mechanism is preferably lubricated so as to ensure a faultless and foolproof operation of the mechanism and it will be understood from the description that the mechanism is completely sealed in in the cavity 22 by laminating the two

arrow portions

12 and 14 together so as to prevent the entrance of moisture or contaminants into the cavity 22.

It will be understood from the foregoing description that by the present invention an effective tensioning device for an archery bow has been provided having a mechanism completely enclosed within said bow and an actuator outwardly of said bow for operation of the mechanism which cooperates with an indicating means provided on the bow to indicate the adjusted tension force of the bow.

Although the present invention has been described with reference to only one preferred embodiment it will be understood that the device is subject to various modifications as may be made by a person skilled in the art to which the invention pertains and such modifications are desired to be included within the scope of the appended claims.

lclaim:

1. In an archery bow having a flexible elongated curvilinear body tapered from the center toward both its ends and a string connected between the ends, the improvement comprising: a handle and bow limb portions having an internal cavity extending from the handle and into the bow limb portions a substantial distance, a pair of identical oppositely disposed elongated members disposed within said cavities for sliding movement therein, with respect to each other, towards and away from the said bow limb portions; said members having end portions overlapping each other at the center of the cavity in the handle and means adjustably connecting said end portions of said members to selectively move said members with respect to each other within said cavity towards or away from said bow limb portions 2. In the improvement as defined in claim 1, said members comprising plates tapered from the handle towards the bow limb portions and each of said end portions of said members being provided with rack teeth in facing relationship to each other 3. ln the improvement as defined in claim 2, said means adjustably connecting said end portions of said members, comprising a pinion disposed for rotation within said cavity between said members for meshing engagement with said rack teeth and means extending outwardly of said bow connected to the pinion for rotation of said pinion so that upon rotation of said pinion said members will be moved in opposite directions relative to each other.

4. In the improvement as defined in claim 3, means provided within said cavity adjacent each of said members for biasing said members towards each other to retain said rack teeth in engagement with said pinion.

5. In the improvement as defined in claim 3, said means extending outwardly of said bow comprising a pinion shaft and a knob, said knob secured to the pinion shaft for manual rotation thereof.

6. In the improvement as defined in claim 5, further comprising indicating means disposed on the outside of said handle and positioned adjacent said knob and said knob having a pointer cooperating with said indicating means to indicate the relative adjusted position of said members within said bow.

7. An archery bow comprising an elongated flexible body, said body having a rigid midportion, said body being tapered in cross section towards its ends from said rigid midportion; said body having a cavity; body tensioning device comprising: reenforcing means disposed within said cavity in said body and adjustably movable therein toward opposite ends of the body for varying the tension of said body, said reenforcing means comprising a pair of overlapping reenforcing members, rotatable means between said overlapping reenforcing members connecting said reenforcing members at said rigid midportion; an actuator for said rotatable means extending outwardly of said midportion and having a hand piece for manual rotation of said rotatable means, said hand piece being adapted to move said reenforcing members in opposite directions with respect to each other upon rotation thereof; said hand piece having a pointer and, indicating means disposed on the outside of said midportion to indicate the adjusted position of said reenforcing members.

8. In the device as defined in claim 7, said rotatable means comprising a pinion disposed within said body cavity at the rigid midportion thereof and between said pair of reenforcing members, said reenforcing members being provided with rack teeth facing each other and adapted for meshing contact with said pinion and said actuator comprising a pinion shaft connecting said pinion to said hand piece.

9. In the device as defined in claim 8, the further provision of biasing means disposed within said body cavity adjacent each of said members and spaced from said rack teeth so as to continuously bias said members towards each other to maintain said rack teeth in meshing engagement with said pinion.

Claims

1. In an archery bow having a flexible elongated curvilinear body tapered from the center toward both its ends and a string connected between the ends, the improvement comprising: a handle and bow limb portions having an internal cavity extending from the handle and into the bow limb portions a substantial distance, a pair of identical oppositely disposed elongated members disposed within said cavities for sliding movement therein, with respect to each other, towards and away from the said bow limb portions; said members having end portions overlapping each other at the center of the cavity in the handle and means adjustably connecting said end portions of said members to selectively move said members with respect to each other within said cavity towards or away from said bow limb portions.

2. In the improvement as defined in claim 1, said members comprising plates tapered from the handle towards the bow limb portions and each of said end portions of said members being provided with rack teeth in facing relationship to each other.

3. In the improvement as defined in claim 2, said means adjustably connecting said end portions of said members, comprising a pinion disposed for rotation within said cavity between said members for meshing engagement with said rack teeth and means extending outwardly of said bow connected to the pinion for rotation of said pinion so that upon rotation of said pinion said members will be moved in opposite directions relative to each other.