WO2006045193A1

WO2006045193A1 - Crossbow cocking and stringing device

Info

Publication number: WO2006045193A1
Application number: PCT/CA2005/001645
Authority: WO
Inventors: Derrick John Middleton
Original assignee: Derrick John Middleton
Priority date: 2004-10-26
Filing date: 2005-10-26
Publication date: 2006-05-04
Also published as: US20060086346A1; CA2585456A1

Abstract

The present invention provides a crossbow stringing and cocking device whereby one person may easily and safely draw back the string of a crossbow to engage the trigger mechanism for shooting of a projectile, and may also be utilized to unstring and string the bow. The invention utilizes a pulley system, mounted inside the barrel for convenience and safety.

Description

CROSSBOW COCKING AND STRINGING DEVICE

FIELD OF THE INVENTION

This invention relates to crossbows.

BACKGROUND OF THE INVENTION

It is well known that crossbows are difficult to cock due to the powerful limbs that are used by this equipment. Over the centuries various apparatus has been developed to provide an easier method for drawing a bow string for engagement with a trigger mechanism. Such devices have included levers, windlasses, built-in pulley systems that are attached to the stock of the bow as well portable rope and pulley means. All of these devices provided some degree of mechanical advantage.

Earlier attempts to assist with cocking have been overly complex such as those described in related United States Patents all by Bednar, being, 6,286,496, 6,095,128 and 6,874,491. These devices preferably are utilized in connection with additional power sources such as hand cranks, powered motors, or powered screwdrivers to assist the user in cocking the crossbow. Redundancy for safety purposes is also not incorporated into these devices.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a cocking device that is less expensive to produce than existing systems.

It is an object of the present invention to provide a cocking device that provides easier storage of the cocking device.

It is an object of the present invention to provide a cocking device that provides redundancy for safety in the event of breakage of a cable or handle during cocking.

It is a further object of the present invention to provide a cocking device that is easier to operate than existing devices.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood, the preferred embodiment thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a bottom view, partly in section, showing a crossbow with the cocking device;

, Figure 2 is a close up side view of the string, handle and pulley; Figure 3 is a bottom view, partly in section, showing both tackles engaged with the string; Figure 4 shows a user cocking a crossbow using the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In orderto more clearly understand the present invention part numbers as assigned in the following parts list will be used: Part Number Description

2 Barrel

3 Prod

4 String

5 Stock

6 Forestock

7 Tackle

8 Handles

9 Opening in Barrel

10 Trigger Latch

11 Cable

12 Spring

13 Trigger Mechanism

14 Stirrup

15 Pulley

A preferred embodiment of the crossbow-cocking device is illustrated in the drawing figures. The conventional crossbow is shown from different angles, as shown in Fig 1. & 3. A user is seen utilizing the cocking mechanism of the present invention is Fig. 4. In Fig. 2 a close up is shown of the handles 8 and tackles 7, as stored. Such a conventional crossbow has a stock with a first end and a second end, a first side and a second side, and prods or limbs 3 attached proximal to the first end of the main beam or barrel that is mounted within the stock 5. A string 4 is attached to the prod or limbs and a trigger mechanism 13 located intermediate the first end and the second end of the stock and beam combined length.

The cocking device is comprised of a pair of guide means each of which have an attaching means, also called tackles 7, attached to the barrel 2, as in Fig 1. for removable attachment to the bowstring. Both guide means engage a cord or the like, that has a first and a second end. Each guide means is retractably connected to a cable 11 uncoiled and straight as possible or rope that has been attached to a compact constant force spring 12 for retraction when not in use. Within the barrel 2 of the cross bow the cable 11 or rope has been attached to one of the ends of a constant force spring 12 or other means for retracting.

By generally simultaneously pulling handles 8 on the first and second ropes or cables the cocking means is extracted at point 9 from the barrel 2 and stretched toward the string 4 of the crossbow. Once the block and tackle are attached to both sides of the crossbow string (Fig. 4) the operator bends down

toward the handles 8, grabs them, and pulls them toward himself while bending upward making sure his foot is in the stirrup 14. This procedure stretches the string to a point that it is able to engage the trigger latch 10 within the barrel that is located between the first and the second end of the said crossbow leaving it in a state ready to be fired or discharged.

The typical crossbow generally consists of longitudinally extending main beam, or barrel member 2 and two outwardly extending limb members or member 3, which extend transversely on opposite sides from main beam or barrel

member. The crossbow bowstring 4 is strung between the distal ends of outwardly extending limbs 3. Stock generally includes a rear portion or tailstock 5 having an integrally formed butt portion that is normally positioned against the user's shoulder when crossbow is being aimed and/or fired. The stock further includes a forestock 6 for holding the main beam or barrel 2, which may be integral to the tailstock 5, or may be provided as a separate member secured therewith.

In the preferred embodiment shown, the barrel 2 is a separate member which may be formed of a strong but lightweight material such as aluminum. Extruded aluminum allows for the mounting of the cocking system that resides in the hollow chamber or chambers of the extrusion.

In one example of this invention the cocking device is comprised of a pair of guide means shown generally as handles (left and right) and removable hooks 7 and pulley 15, also referred to as block and tackle 7. As can be seen more clearly in FIG 1. the pulley is comprised of a block and a sheave 7 . In the preferred embodiment the main beam or barrel 2 is formed from aluminum but may be made from any suitable material. A cord or cable 11 is provided having a first end and a second end , as illustrated in Fig. 1 & Fig. 3. Fig. 3 shows the first end of the cable 11 passing through the pulley 15 of the guide means or block and tackle 7 and attached thereafter to a handle 8 to aid in the cocking process. The other end of cable 11 enters the barrel 2 on opposing sides of the same at 9 somewhat rear of the string latching means 10, from the out side of the barrel 2 continuing to the inside of the extrusion or other and attached thereto 12.

In the preferred embodiment a constant force spring 12 is used due to its compact size and its excellent characteristics of equal not' increasing force throughout its extension, as would be found in extension of coil springs, elastic or surgical tubing as well, gas or air filled shocks and lastly a spring loaded hub that usually includes a clock type spring that has an increase force as it is wound and needs ample space for mounting or installation of such a hub system.

Handle 8 is attached for removable attachment to 16 the two are of equal shape in tapered dimensions like male and female, the handle 8 is larger dimensionally than 16. Both have a complimenting taper with the greater of the tapers facing the butt end, thus the handles are secure due to the fit and secondly by the constant force spring that has a constant force oh them in the direction of the larger tapers.

. In the operating position as seen in FIG 2. each guide means 7 is removed from holder 16 that is attached to 2 and pull extracted from hole 9. Once the length, of cable is extracted from the barrel or main beam 2 where it resides

when not. in use, the hooks or block and tackle 7 are extended toward the prod 3 and attached to the bow string 4. Each hook is attached at a point adjacent to opposing sides of the barrel. The handles 8 one per side as illustrated are pulled in both hands on separate sides of this barrel with your foot in 14, the mechanical

advantage of the pullies which in this case is 50% between the pair of guide means.

In the preferred embodiment the cord is made from woven nylon fibers; however, the cord may be constructed of any suitable material, as Well using the one pulley per side we have a mechanical advantage of 50%. Anyone skilled in this art would be able to accommodate a multiple pulley system with increased mechanical advantage that could also be used in the extruded chambers; one could also reverse the whole assembly to operate from the opposite end.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above article without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

WHAT IS CLAIMED AS THE INVENTION IS:

1. A crossbow comprising:

A longitudinally extending main beam having a longitudinally extending track

thereon; a pair of outwardly extending arms having distal ends, said pair of outwardly extending arms extending transversely from opposite sides of said longitudinally extending main beam;

a crossbow bowstring attached to said distal ends of said pair of outwardly extending arms;

a crossbow trigger mechanism mounted on said longitudinally extending main beam; a claw member mounted to move along said longitudinally extending track of said longitudinally extending main beam, said claw member having a first attachment point on a first side of said longitudinally extending track and a second attachment point on a second side of said longitudinally track, said claw member being capable of moving said crossbow bowstring from a first uncocked position to a second cocked position in said crossbow trigger mechanism; and

a crossbow bowstring drawing mechanism including a first string member along said first side of said longitudinally extending track, said first string member having a distal end attached to said first attachment point of said claw member, and a second string member along said second side of said longitudinally extending track, said second string member having a distal end attached to said second attachment point of said claw member, said crossbow drawing mechanism being capable of retracting said first string member and said second string member along said longitudinally extending track at substantially the same rate.

2. The crossbow in accordance with claim 1 , wherein said crossbow bowstring drawing mechanism includes a first hub member positioned on said first side of said longitudinally extending track to retract and store said first string member thereon and a second hub member positioned on said second side of said longitudinally extending track to retract and store said second string member thereon.

3. The crossbow in accordance with claim 1 or 2, wherein said claw member is capable of moving said crossbow bowstring from a second cocked position back to a first uncocked position.

4. A crossbow bowstring cocking mechanism for a crossbow having a longitudinally extending main beam, a pair of outwardly extending arms having distal ends, the pair of outwardly extending arms extending transversely from opposite sides of the longitudinally extending main beam, a bowstring attached to the distal ends of the pair of outwardly extending arms and a trigger mechanism mounted on the longitudinally extending main beam, said cocking mechanism comprising:

a claw member selectively mounted to move along the longitudinally extending main beam, said claw member having a first claw side positioned on a first side of the main beam and a second claw side positioned on a second side of the main beam, said claw member being capable of moving the bowstring between a first uncocked position and a second cocked position in the crossbow trigger mechanism;

at least one string member forming a first string section along the first side of the main beam, said first string section engaging said first claw side; and

a second string section along the second side of the main beam, said second string section engaging said second claw side, and a drawing mechanism being capable of retracting said first and said second string sections along the main beam at substantially the same rate.

5. A crossbow cocking device comprising a drawing mechanism for converting rotational power from an input source into longitudinal movement of at least one r string member coupled to said drawing mechanism, said at least one string member also being operatively connected to a bowstring engaging member to cause corresponding longitudinal movement of said engaging member upon operation of said input source, wherein said drawing mechanism includes a retraction device to cause retraction of said at least one string member in association with said drawing mechanism when said bowstring engaging member is not engaged with a bowstring.

6. The crossbow cocking device in accordance with claim 5, wherein said drawing mechanism includes a reduction gearing system to convert rotational power from said input source into said longitudinal movement of said claw member at a

predetermined gear ratio.

7. The crossbow cocking device in accordance with claim 5 or 6, wherein said at least one string member includes a first string portion operatively connected to a first side of said claw member, and a second string portion operatively connected to a second side of said bowstring engaging member, said drawing mechanism being capable of retracting said first string portion and said second string portion at substantially the same rate.

8. The crossbow cocking device in accordance with claim 5, 6, or 7, wherein

said drawing mechanism includes a first hub member to retract and store said first string portion thereon and a second hub member to retract and store said second string portion thereon and at least one spring member, wherein said hubs are spring loaded by said spring member allowing them to rewind said string portions automatically when said hub members are free to rotate and when said string portions are not under a restraining force.

9. The crossbow cocking device in accordance with claim 5, 6 , 7, or 8 , wherein said drawing mechanism is capable of moving said bowstring engaging member and

a crossbow bowstring engaged therewith from a cocked position back to a uncocked

position.

10. The crossbow cocking device in accordance with claim 5, 6, 7, 8, or 9 wherein said drawing mechanism includes a selectively posϊtionable locking

mechanism, wherein said locking mechanism is positionable to prevent release of said at least one string member while allowing retraction of said at least one string member.

11. The crossbow cocking device in accordance with claim 5, 6, 7, 8, 9, or 10 wherein said device is contained in a housing.

12. The crossbow cocking device in accordance with claim 11 , wherein said housing is mounted integral to a stock of a crossbow.