Bow-Type Throwing Tool

Abstract

A bow-type throwing tool includes a central body, a nocking string for an arrow, and elastic energy storage mechanism operated by the traction of the string. The elastic energy storage mechanism includes: two opposed primary levers connected with hinging to the central body, the nocking string being constrained by its opposite ends to opposite free ends of the primary levers; two opposed axial action thrust accumulators, defined on the central body; a loading element of the axial action thrust accumulators configured to induce a compression in the thrust accumulators following a traction of the nocking string.

1 . A bow-type throwing tool, comprising a central body, a nocking string for an arrow, and elastic energy storage means operated by the traction of said string,
 said elastic energy storage means comprising:
 two opposed primary levers connected with hinging means to said central body, said nocking string being constrained by its opposite ends to opposite free ends of said primary levers; 
 two opposed axial action thrust accumulators, defined on said central body; 
 loading means of said axial action thrust accumulators configured to induce a compression in said thrust accumulators following a traction of said nocking string, 
   wherein said axial action thrust accumulator comprises at one end a fixed head and at the opposite end a movable head, said axial action thrust accumulator comprising a stem, translatable in the direction of its own axis, to which said movable head is constrained,   said loading means comprising, for each thrust accumulator:
 a loading thread, which is fixed at a first end to the central body and at the opposite second end to a corresponding primary lever; 
 a pulley system configured to cause a translation of said stem, along the line of said axis and in the compression direction of a corresponding thrust accumulator, following a traction of said loading thread. 
   
     
     
         2 . The throwing tool according to  claim 1 , wherein said hinging means comprise for each primary lever a pin, a notch being made on said pin for the passage of said loading thread, said notch being configured to allow the progressive reduction of the distance between the axis of the loading thread and the rotation axis of said pin during the traction step of the nocking string. 
     
     
         3 . The throwing tool according to  claim 1 , wherein the distance of the axis of the loading thread from the rotation axis of the pin is near zero, remaining greater than zero. 
     
     
         4 . The throwing tool according to  claim 1 , wherein said pin, at said notch, has a solid part configured to define a curved surface for the rest of said loading thread, said curved surface having a cusp, the distance between said cusp and the rotation axis of said pin being less than the radius of said loading thread. 
     
     
         5 . The throwing tool according  claim 1 , wherein said central body comprises hinging appendages. 
     
     
         6 . The throwing tool according to  claim 1 , wherein each primary lever comprises a free end and an opposite pivoting portion. 
     
     
         7 . The throwing tool according to  claim 1 , wherein said central body comprises two opposite frames each defining a window, inside each of which windows there is a corresponding thrust accumulator. 
     
     
         8 . The throwing tool according to  claim 1 , wherein each of said axial action thrust accumulators comprises at least one compression load spring, said axial action thrust accumulator comprising, in particular, a plurality of Belleville springs, arranged in series with each other. 
     
     
         9 . The throwing tool according to  claim 1 , wherein said thrust accumulator comprises a stroke adjustment system, configured to limit the crushing of one or more springs. 
     
     
         10 . The throwing tool according to  claim 1 , wherein said stem has a manoeuvring end, available for the connection with the loading means. 
     
     
         11 . The throwing tool according to  claim 1 , comprises a pair of load increase devices, configured to operate in series with a corresponding thrust accumulator. 
     
     
         12 . The throwing tool according  claim 1 , wherein said load increase device comprises:
 a stem of the thrust accumulator, which is equipped with a striker head;   a containment box, fixed externally to the end of the frame;   a slider body placed so as to translate, along the thrust axis of the corresponding thrust accumulator, into a through hole defined at the end of the frame and into a coaxial guide hole defined in the containment box;   a plurality of thrust increase springs, placed so as to act between a cover of the containment box and a shoulder of the slider body;   an abutment element, configured to abut against the striker head of the stem, said abutment element being configured to be able to adjust its own axial position with respect to the slider body itself.   
     
     
         13 . The throwing tool according to  claim 1 , comprises a pair of pre-loadable external auxiliary accumulators configured to operate in series with a corresponding thrust accumulator. 
     
     
         14 . The throwing tool according to  claim 1 , comprising:
 a stem of a corresponding thrust accumulator, which is equipped with a striker head;   a containment box, fixed externally to the end of the frame;   a first slider body placed so as to translate, along the thrust axis of the corresponding thrust accumulator, into a through hole defined at the end of the frame);   a second slider body placed so as to translate, along the thrust axis, into a guide hole defined on the first slider body and into a coaxial guide hole defined in the containment box;   a plurality of thrust increase springs, placed so as to act between a cover of the containment box and a first shoulder of the second slider body;   one or more accompanying springs, placed so as to act between the shoulder of the second slider body and a facing second shoulder of the first slider body;   a pre-load lever, pivoted to a bracket developing from the cover through a pin;   a pre-load tie rod connected at a first end to a first traction pin fixed to the second slider, and at the opposite second end to a second traction pin fixed to the pre-load lever;   an elastic return element constrained on one side to the cover and on the opposite side to the pre-load lever.   
     
     
         15 . The bow-type throwing tool configured as a crossbow, characterized in that it comprisescomprising a central body from which a tiller , a nocking string for a dart and elastic energy storage means operated by the traction of the string develop, said elastic energy storage means comprising:
 two opposed primary levers connected with respective hinging means to said central body, said nocking string being constrained by its opposite ends to opposite free ends of said primary levers   an axial action thrust accumulator, defined on said tiller;   loading means of said axial action thrust accumulator, said loading means being configured to induce a compression in the thrust accumulator following a traction of said nocking string.   
     
     
         16 . A bow-type throwing tool, comprising a central body, a nocking string for an arrow, and elastic energy storage means operated by the traction of said string,
 said elastic energy storage means comprising:
 two opposed primary levers connected with hinging means to said central body, said nocking string being constrained by its opposite ends to opposite free ends of said primary levers; 
 two opposed axial action thrust accumulators, defined on said central body; 
 loading means of said axial action thrust accumulators configured to induce a compression in said thrust accumulators following a traction of said nocking string. 
   
     
     
         17 . Hinging means for a bow-type throwing tool, said bow-type throwing tool comprising a central body, a nocking string for an arrow, and elastic energy storage means operated by the traction of said string, said elastic energy storage means comprising two opposed primary levers connected with said hinging means to said central body, said hinging means comprising, for each primary lever, a pin, a notch being made on said pin for the passage of a loading thread, said notch being configured to allow the progressive reduction of the distance between the axis of said loading thread and the rotation axis of said pin during the traction step of the nocking string. 
     
     
         18 . The hinging means according  claim 17 , wherein the distance of the axis of the loading thread from the rotation axis of the pin is near zero, remaining greater than zero. 
     
     
         19 . The hinging means according to  claim 17 , wherein the distance between the cusp and the rotation axis of the pin is less than the radius of the loading thread. 
     
     
         20 . The hinging means according to  claim 17 , wherein said notch is shaped in such a way that the axis of the loading thread stops at a distance from the axis of the pin which can be comprised between 1 and 5 hundredths of a millimeter, wherein
 said distance between the axis of the pin and the axis of the loading thread corresponds to the difference between the radius of the loading thread and the distance between the cusp and the axis of the pin.   
     
     
         21 . A pin for bow-type throwing tools, wherein a notch is made on said pin for the passage of a loading thread, said notch being configured to allow the progressive reduction of a distance between an axis of said loading thread and a rotation axis of said pin. 
     
     
         22 . The pin according to  claim 21 , wherein at the notch, it has a solid part configured to define a curved surface for the rest of the loading thread. 
     
     
         23 . The pin according to  claim 21 , wherein the notch is concave and the solid part of the pin is correspondingly convex. 
     
     
         24 . The pin according to  claim 22 , wherein the curved surface has a cusp. 
     
     
         25 . The pin according to  claim 22 , wherein the axis of the pin crosses the pin at the notch, and not at the solid part. 
     
     
         26 . The pin according to  claim 21 , wherein said notch develops like an arc of a circle over an angle comprised between 180° and 200°. 
     
     
         27 . A load increase devices, configured to operate in series with a corresponding thrust accumulator, said load increase device comprising:
 a stem of the thrust accumulator, which is equipped with a striker head,   a containment box, fixed externally to the end of a frame,   a slider body placed so as to translate, along the thrust axis of the corresponding thrust accumulator, into a through hole defined at the end of the frame and into a coaxial guide hole defined in the containment box,   a plurality of thrust increase springs, placed so as to act between a cover of the containment box and a shoulder of the slider body.   
     
     
         28 . The load increase devices according to  claim 27 , wherein said slider body also comprises an abutment element, configured to abut against the striker head of the stem, said abutment element being configured to be able to adjust the axial position with respect to the slider body itself, with the aim of defining the distance with the striker head. 
     
     
         29 . A pre-loadable external auxiliary accumulator comprising:
 a stem of a thrust accumulator which is equipped with a striker head;   a containment box, fixed externally to the end of a frame;   a first slider body placed so as to translate, along a thrust axis of the corresponding thrust accumulator, into a through hole defined at the end of the frame;   a second slider body placed so as to translate, along the thrust axis, into a guide hole defined on the first slider body and into a coaxial guide hole defined in the containment box;   a plurality of thrust increase springs, placed so as to act between a cover of the containment box and a first shoulder of the second slider body;   a pre-load lever, pivoted to a bracket, developing from the cover, through a pin;   a pre-load tie rod constrained at a first end to a first traction pin fixed to the second slider, and at the opposite second end to a second traction pin fixed to the pre-load lever;   an elastic return element constrained on one side to the cover and on the opposite side to the pre-load lever.   
     
     
         30 . The pre-loadable external auxiliary accumulator according to  claim 29 , further comprising:
 one or more accompanying springs, placed so as to act between the first shoulder of the second slider body and a facing second shoulder of the first slider body;   a stroke adjustment system for said accompanying springs, defined below by way of example by the striker perimeter wall.