EP1202020A1

EP1202020A1 - Device for the attachment of the elastic ties to the stock of a spear gun

Info

Publication number: EP1202020A1
Application number: EP00122980A
Authority: EP
Inventors: Valerio Grassi
Original assignee: Seatec Di Marcelli Amedeo & C Sas
Current assignee: Seatec Di Marcelli Amedeo & C Sas
Priority date: 2000-10-23
Filing date: 2000-10-23
Publication date: 2002-05-02

Abstract

A device for the attachment of elastics (10, 10') to the stock of a spear gun comprising a support (1) fixed to the free end of stock (2), and an elastics-bearing-head (4) tiltingly pivoted in said support (1). Support (1) is provided with a slit (5) communicating with an enlarged cavity (6) and the elastics-bearing-head (4) comprises two fixing means (9, 9') for elastics (10, 10'), opposed and parallel with each other, and an intermediate transversal arm (11) connecting said fixing means (9, 9'); said intermediate arm (11) having a size such that it can be inserted in said slit (5) and cavity (6) and rotated therein.

Description

The present invention relates to an attachment device of the elastic ties to the stock of a spear gun.
More particularly, the present invention relates to a device for the attachment of elastic ties to the stock of a spear gun, in particular of the "arbalete" type, which allows an easy and quick hooking and unhooking.
As is known, the arbalete-like spear gun is a weapon provided with elastics, capable of throwing a spear or an harpoon at a distance of several meters. It comprises a stock, a long metal staff that ends with an harpoon or a spear; a propulsion means constituted of elastic ties; and a butt or grip comprising a means for the attachment of the staff and a trigger for activating by hand said hooking means.
The propulsion means constituted of elastic ties comprises two elastics placed above the barrel and parallel to the metallic staff. Each tie is screwed to a head fixed to the stock of the spear gun by known fixing means, such as for instance a pin, and at the opposite end it is provided with an end fork that engages in a special notch of the staff.
The connection between the elastic ties and the fork is realized by means of bushings from plastic material, such as for instance nylon, and by means of a connecting metal arm between each bushing and the end fork.
The gun is loaded by drawing the elastic until the hooking notch is reached and locking the end fork in said notch of the staff. By pressing the trigger, the hooking means lowers and unhooks the staff; the free elastics produce on the staff an effect very similar to the one of the arch on an arrow.
The main drawback of such spear guns lies in that the operations of disassembly, replacement and fixing of the elastics to the gun stock often require the use of special tools. Therefore, such operations require much time and, in any case, they cannot be easily performed in the water. Therefore, in case of breaking of the elastics, the user must come out from the water to carry out the replacement.
Besides, as the elastics are parallel to the staff and the stock axis, during their tension, the stock is submitted to a combined effort both of the elastics and the staff and can bend or bulge. Such drawback can be eliminated by producing the stock with very resistant materials, such as for instance carbon fibers, which are however very expensive and affect markedly the cost of the gun.
Object of this invention is to obviate the above drawbacks.
More particularly, object of the present invention is to provide a device for the attachment of the elastics to the stock of a gun such as to allow a quick and easy replacement of the elastics also in the water, without having recourse to the help of any tool.
A further object of the present invention is to provide a device for the attachment of the elastics to the stock of a gun such as to prevent any possible bending or bulging of the stock during the tensioning of the elastics.
According to the present invention, these and other objects are achieved by employing an attachment device comprising a support fixed to the free end of the stock, and an elastics-bearing-head tiltingly pivoted in said support.
Preferably, the support is provided with a slit communicating with an enlarged cavity having preferably a circular section.
The elastics-bearing-head comprises two fixing means for the elastics, opposite and parallel with each other, and an intermediate transversal arm connecting said fixing means. Said intermediate arm, which is inserted in said cavity, has a thickness lower than the aperture of the slit and a length greater than its thickness but smaller than the diameter of the cavity.
The fixing means and the intermediate connecting arm may be obtained as a single piece and from the same material, which may be an aluminum alloy or a plastic material, such as for instance ABS, polycarbonate, polyester, nylon, etc., either reinforced or not reinforced.
According to a preferred embodiment, the slit of the support with the cavity is shaped as a key-lock and the elastics-bearing-head has a "H"-shaped section wherein the two vertical arms represent the fixing means and the orthogonal arm the connecting one.
The intermediate connecting arm may have a rectangular section with rounded-off corners or, preferably, an elliptic section whose smaller diameter is lower with respect of the slit aperture and the greater diameter is lower with respect to the diameter of the cavity.
The means for the fixing of the elastics to the head may be of any known type; preferably, said fixing means comprise a hollow cylinder provided with a threading and a ring nut fixed to the end of the elastics and screwed on said hollow cylinder.
The attachment of the elastics to the stock of a gun by means of the device of the present invention is obtained as follows.
The support is fixed to the end of the stock with the slit facing the stock side opposite to the one of the staff. The elastics-bearing-head is so oriented that the intermediate arm has its greater side or diameter parallel to the axis of the slit. Then, the elastics-bearing-head is introduced in said slit and, afterwards, in the cavity and so rotated as to arrange the elastics in loading position, i.e. with the fork in correspondence of the grip. In such position, the intermediate arm is located in the cavity with its greater side or diameter orthogonal to the slit axis.
The constructive and functional characteristics of the attachment device of the present invention may be better understood thanks to the following description, wherein reference is made to the attached drawings which represent a preferred embodiment reported by way of non-limiting example and wherein:
Figure 1 is a schematic side view of the attachment device of the present invention,
Figure 2 is a schematic, partly sectioned, top view of the attachment device of Figure 1,
Figure 3 is the enlarged schematic view of a section of the device of Figure 2, obtained with a plane passing along the A-A line,
Figures 4 and 5 are enlarged schematic views of the device of the present invention during the steps of insertion of the elastics-bearing-head into the support, and
Figure 6 is a schematic top view of the elastics-bearing head.
With special reference to the figures, the attachment device of the present invention comprises a support 1 fixed to the free end of stock 2 of a gun by means of screws 3, pins or other fixing means, and an elastics-bearing-head 4 tiltingly pivoted in said support 1.
Support 1 may be produced separately and fixed to the free end of the gun stock or may be produced together with the stock, forming one only piece with said stock.
Support 1 is provided at the free end with a slit 5 communicating with an enlarged cavity 6. Preferably, cavity 6 has a circular section with a diameter whose size is greater than the width of slit 5. The cross-section of slit 5 with cavity 6 has a key-lock shape. On the side opposite to that wherein slit 5 is obtained, support 1 is provided with a guide cylindrical tube 7 wherein the metallic staff 8 is inserted that ends with the harpoon, and in the middle part, with a hole 15 for the line.
The elastics-bearing-head 4 comprises two fixing means 9, 9' for the elastics 10, 10', parallel and opposite, and an intermediate transversal arm 11 connecting said fixing means 9, 9'. Preferably, the elastics-bearing-head 4 has a "H"-shaped section, wherein the two vertical parallel arms correspond to both fixing means 9, 9', and the intermediate one, orthogonal to the first ones, corresponds to the connecting arm 11.
The intermediate connecting arm 11 has a thickness lower than the aperture of the slit 5 and a length greater than its thickness, but lower than the diameter of cavity 6. Said intermediate diameter 11 may have a rectangular section with rounded off comers or an elliptic section with the smaller side or diameter of a size smaller than the width of slit 5 and the greater side or diameter of a size smaller than that of the diameter of cavity 6. The greater side or diameter is parallel to the axis of the fixing means 9, 9'.
The fixing means 9, 9' and the intermediate connecting arm 11 may be obtained as one only piece and from the same material such as, for instance and preferably, from aluminum alloy.
Each fixing means 9, 9' preferably comprises a threaded hollow body having a circular section and a threaded ring nut 12, 12' fixed to the end of elastic 10, 10' and screwed on the hollow body.
The free end of each elastic 10, 10' is connected to an arm 13, 13' by means of bushings and both arms 13, 13' are connected to the end fork 14 through articulated means.
With special reference to figures 5 and 6, the attachment of the elastics 10, 10' to stock 2 of a gun by means of the device of the present invention is obtained as follows.
Support 1 is fixed to the end of stock 2 by means of screws 3 with slit 5 facing the side of the stock opposite to the one of staff 8. The elastics-bearing-head 4 is so oriented that the intermediate transversal arm 11 has its greater side or diameter parallel to the axis of slit 5. Then, the elastics-bearing-head is introduced in said slit 5 and, afterwards, in cavity 6 and so rotated as to arrange the elastics 10, 10' in loading position, i.e. with the fork 14 in correspondence of the grip. In such position, the intermediate arm 11 is located in cavity 6 with its greater side or diameter orthogonal to the axis of slit 5.
From the above description the advantages achieved by the attachment device of the present invention are evident. In fact, it allows to perform the assembly and disassembly of the elastics also in the water, in an easy, rapid and comfortable manner by means of a simple rotation of the elastics-bearing-head 4, without employing apparatuses or tools.
A further advantage lies in that by operating the elastics diagonally and from the side opposite, with respect to the stock axis, to that where the staff is located, any bending or bulging of the stock during the loading and tensioning stage is prevented.
Last but not least, the elastics are not fixed but can rotate about the hooking point, orienting in the exact position required by the staff.
While the present invention has been described with reference to a preferred embodiment, various changes and variants may be introduced in the attachment device of the present invention in the light of the above teaching.
Therefore it is implicit that the present invention comprises all the changes and variants that fall within the spirit and protection scope of the following claims.

Claims

A device for the attachment of elastics (10, 10') to stock (2) of a spear gun comprises a support (1), fixed to the free end of stock (2) and an elastics-bearing-head (4) tiltingly pivoted in said support (1).
The attachment device according to claim 1, wherein support (1) is provided with a slit (5) communicating with an enlarged cavity (6) and the elastics-bearing-head (4) comprises two fixing means (9, 9') for elastics (10, 10'), opposed and parallel with each other, and a transversal intermediate arm (11) for the connection of said fixing means (9, 9'); said intermediate arm (11) having a thickness lower than the aperture of slit (5) and a height greater than its thickness and smaller than the diameter of cavity (6), so as to be inserted in said slit (5) and cavity (6) and rotated therein.
The attachment device according to claim 1 or 2, wherein cavity (6) has a circular section with a diameter of a size greater than the thickness of the slit.
The attachment device according to claim 2 or 3, wherein slit (5) with cavity (6) have a key-lock shaped cross section.
The attachment device according to any of the preceding claims, wherein the elastics-bearing-head (4) has a "H"-shaped section with both fixing means (9, 9') vertical and parallel, and the intermediate connection arm (11) orthogonal to the first ones.
The attachment device according to any of the preceding claims 2 to 5, wherein the intermediate arm (11) has a rectangular section with rounded off corners, wherein the smaller side has a smaller size with respect to the width of slit (5) and the greater side has a smaller size with respect to that of the diameter of cavity (6); the greater size being parallel to the axis of the fixing means (9, 9').
The attachment device according to any of the preceding claims 2 to 5, wherein the intermediate arm (11) has an elliptic section with the smaller diameter having a smaller size with respect to the width of slit (5) and the greater diameter has a size smaller that that of the diameter of cavity (6); the greater diameter being parallel to the axis of the fixing means (9, 9').
The attachment device according to any of the preceding claims 2 to 7, wherein the fixing means (9, 9') and the intermediate connecting arm (11) are obtained in one only piece and from the same material.
The attachment device according to claim 8, wherein the fixing means (9, 9') and the intermediate connecting arm (11) are obtained from aluminum alloy.
The attachment device according to any of the preceding claims, wherein each fixing means (9, 9') comprises a threaded hollow body having a circular section and a threaded ring nut (12, 12') fixed to the end of elastics (10, 10') and screwed on the hollow body.
The attachment device according to any of the preceding claims, wherein support (1) and stock (2) form one only piece.