Abstract:
The present invention relates to a semi-automatic anchor shooter, more particularly to a powder-actuated anchor shooter which may shoot anchors at high precision and has a muffler chamber to minimize the noise from the explosion of powder. The disclosed anchor shooter consists of a shooting mechanism and a thrusting mechanism. The shooting mechanism provides convenient and precise aiming, and the thrusting mechanism provides buffer shooting, these together with a shell-free powder chain and a powder feeding mechanism enable the anchor shooter to steadily, efficiently, and powerfully shoot and implant anchors into a structural material at high precision.

Description:
BACKGROUND OF THE INVENTION 
     A conventional powder-actuated fastening tool for thrusting anchors into hard cement wall or rock wall by means of explosive force produced by powders is shown in FIGS. 7 and 8, which is a substantially tubular tool and mainly includes a chamber tube 1a, a discharge tube 2a, a shell remover 3a, a sleeve 4a, a coupling 5a, an inner sliding block 6a, and a handle 7a. The chamber tube 1a is received in the discharge tube 2a, the discharge tube 2a has a front cover 21a and a rear cover 22a to substantially close two ends thereof, the shell remover 3a extends at one end into the chamber tube 1a and bears at a rear portion thereof an inner spring 31a, a limit nut 32a is screwed to a rear end of the shell remover 3a to prevent the inner spring 31a from moving out of the shell remover 3a and thereby limits the displacement range of the shell remover 3 a. The chamber tube 1a has a threaded rear end which extends out the rear cover 22a of the discharge tube 2a to engage with the coupling 5a so that the rear end of the shell remover 3a along with the inner spring 31a extends into the coupling 5a. An outer spring 33a is put over the inner spring 31a to enable the sleeve 4a to springily slide over the coupling 5a. A positioning slot 51a is provided at each side of the coupling 5a, and, pin holes 41a are provided on the sleeve 4a corresponding to the positioning slots 51a. A pin 42a is inserted into the pin hole 41a at one side of the sleeve 4a and extends through the internal sliding block 6a to fix the same in the hollow coupling 5a. When the sleeve 4a slides forward over the coupling 5a, it brings the sliding block 6a  to move together so that the sliding block 6a may push the limit nut 32a  screwed to the rear end of the shell remover 3a, causing the same to remove the shell in a longitudinal direction. 
     To operate such a conventional powder-actuated fastening tool, first insert a shaped powder 8a into a stepped hole at a front of the chamber tube 1a, then, position an anchor 9a having a ring 91a in a front inner hole of the chamber tube 1a, allowing a distance left between the hammering end of the anchor 9a and the shaped powder 8a. The ring 91a of the anchor 9a is fixedly attached to the anchor 9a and is used to seal the front opening of the chamber tube 1a so that the interior of chamber tube 1a forms a closed explosion chamber and to maintain the distance left between the anchor 9a and the powder 8a. When an anchor 9a is to be forced into a wall or other structural material, such as the light-weight steel frame below the ceiling, screw the handle 7a to the rear end of the above-described fastening tool, aim the anchor 9a at the desired spot, and make strenuous efforts to push the handle 7a, causing the anchor 9a to disengage from the ring 91a and shifts backward. When the hammering end of the anchor 9a contact the percussion cap of the powder 8a, the powder 8a explodes, and the explosive pressure so produced in the closed chamber of the chamber tube 1a pushes the anchor 9a in a reverse direction toward the wall or the target with a extremely big hammering force. When the anchor 9a is hammered into the wall or the target, the ring 91a shall be forced to a rear position near the hammering end of the anchor 9a. 
     There are several disadvantages existed in the conventional powder-actuated fastening tool and needing improvement: 
     1. The anchor 9a projects out of the front end of the chamber tube 1a. For the anchor 9a to disengage from the ring 91a and move back an adequate distance within an instantaneous moment, the user must keep the anchor 9a at an adequate launching distance from the wall or target and aim the anchor 9a at the desired spot and push the handle 7a instantaneously to hammer the anchor 9a in place. However, since there is a launching distance left between the anchor 9a and the wall, and the long handle 7a may not be always pushed steadily to precisely aim the anchor 9a at the target, the anchor 9a is frequently forced into a place deviated from the desired point and must be extracted from the wall and another anchor 9a must be hammered again. All of these cause waste in time, labor and material. The design thereof is not practical nor economical. 
     2. The handle 7a must be strenuously pushed in an instantaneous moment so that the hammering end of the anchor 9a may contact the percussion cap of the shaped powder 8a to explode the powder 8a. The operation is laborious and inconvenient. 
     3. The powder 8a can be used to hammer only one single anchor 9a each time. The user has to re-load the anchor 9a and shaped powder 8a each time an anchor 9a is hammered. The efficiency in using the conventional powder-actuated fastening tool is therefore very low. 
     4. All the conventional powder-actuated fastening tools available in the market do not have muffler, and the loud noise from explosion during operation might have reverse influence on the living quality of area surrounding the working site, especially when the site is in the residential or school district. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a powder-actuated anchor shooter with which the anchor may be automatically, conveniently, continuously, and precisely shot to the desired spots. Meanwhile, the noise from explosion of powder can be muffled. 
     The powder-actuated anchor shooter according to the present invention mainly consists of a shooting mechanism and a thrusting mechanism. The shooting mechanism provides convenient and precise aiming, and the thrusting mechanism provides buffer shooting, these together with shell-free powder chain and powder feeding mechanism enable the anchor shooter to steadily, efficiently, and powerfully implant anchors into a structural material at high precision. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a disassembled perspective of the present invention; 
     FIG. 2 is a-sectional view of the present invention showing the operation thereof; 
     FIG. 3 is still a sectional view of the present invention showing the operation thereof; 
     FIG. 4 is a partial sectional view of the present invention showing the restoring of the shooting mechanism thereof after an anchor is shot; 
     FIG. 5 illustrates the centre rod of the thrusting mechanism of the present invention; 
     FIG. 6 illustrates an embodiment of the present invention; 
     FIG. 7 is a disassembled perspective of a conventional powder-actuated fastening tool; and 
     FIG. 8 is a sectional view of the conventional fastening tool shown by FIG. 7. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Please refer to FIG. 1. The present invention mainly consists of a shooting mechanism 1 and a thrusting mechanism 2. The shooting mechanism 1 includes a main body 11, an inner tube 12 disposed in a front portion of the main body 11, a shooting assembly 13, a dust guard 15, and a hammer 14 disposed in a rear portion of the main body 11. 
     The shooting assembly 13 further includes a hollow body member 131, a head member 132, and a piston rod 133. The piston rod 133 is disposed in the coupled hollow body member 131 and head member 132 and can reciprocate therein. 
     The inner tube 12 is received in the front hollow portion of the main body 11 and the shooting assembly 13 is then received in the inner tube 12. A screw 16 passes through a hole formed on the main body 11 and extends into the inner tube 12 before being retained in an elongated slot 134 formed on the hollow body member 131, such that the shooting assembly 13 may reciprocatingly displace inside the inner tube 12 within a predetermined range. A coil spring 122 and a steel ball 123 received in front of the coil spring 122 are fixed to each side of a rear seat of the inner tube 12 by a screw 121, such that the steel balls 123 protrude into an inner side of the rear seat of the inner tube 12 to springily clamp between them a powder chain 17 by engaging with one of the continuous recess pairs 171 formed at two sides of the powder chain 17. The powder chain 17 extends into the main body 11 from a bottom opening of a front grip 111 of the main body 11 and is moved upward in one direction by means of a springy trigger 18. The powder chain 17 consists of a series of powder packs 172 each of which locates between two adjoining recess pairs 171 and is thereby positioned in place by the steel balls 123. The springy trigger 18 consists of a lever 181 inclinedly extending between the front grip 111 and the rear portion of the main body 11 and an inclined plate 182 connected to a front end of the 1ever 181. A spring 183 connects with the lever 181 at a point near its central portion to give the lever 181 some extent of spring force, so that the trigger 18 may be springily moved to displace the powder chain 17 in one direction. 
     A spring 141 and a hollow housing 142 are put over the hammer 14 disposed in the rear portion of the main body 11. A first connection piece 19 behind the hammer 14 fixes the hammer 14, spring 141 and hollow housing 142 in the main body 11 such that a pointed head of the hammer 14 reaches into the rear seat of the inner tube 12, as shown in FIGS. 2 and 3, pointing to a percussion position of the positioned powder pack 172. A restoring bar 143 is disposed between the hollow housing 142 of the hammer 14 and the shooting assembly 13 to maintain the relative position of the two. That is, when the shooting assembly 13 restores to its original position, the bar 143 shall push the hammer 14 backward and stop the same in place lest the feeding of powder chain 17 should be hindered. 
     A substantially closed muffler chamber 112 is provided at a lower front of the main body 11 and is communicable with the main body 11 via a through hole 6 provided at the top of the muffler chamber 112, as shown in FIGS. 2 and 3. A cover 114 is fixed to a front opening of the muffler chamber 112 by means of a screw 113 and has a through hole 115 formed at a predetermined position thereon. When one of the powder packs 172 is set off to explode in the main body 11, the high-pressure gas so produced may be guided into the muffler chamber 112 via the through hole 6 and then be slowly discharged from the through hole 115. With the hollow muffler chamber 112, the sound wave of sonic boom produced in the main body 11 shall be enclosed and reflect within the substantially closed muffler chamber 112 without leaking out there. The noise brought along with the explosion of powder pack 172 is thereby largely reduced. 
     The thrusting mechanism 2 of the present invention consists of a coupling 21, a sliding block 22, a centre rod 23, a connection member 24, a spring 25, a hollow push member 26, an inner hexagon screw 27, a second connection piece 28, and a sleeve 29. Please refer to FIGS. 1, 2 and 3. The coupling 21 is screwed to a rear end of the first connection piece 19 of the shooting mechanism 1 and has a middle partition 211 therein. All the centre rod 23, sliding block 22, and connection member 24 are received in the coupling 21. 
     The centre rod 23 is a slender rod having a front head 231 with larger outer diameter and a threaded rear end to engage with the connection member 24. The front head 231 of the centre rod 23 is retained to one front side of the middle partition 211 of the coupling 21 and a rear portion of the centre rod 23 is received in the sliding block 22 and the connection member 24 behind the sliding block 22. 
     Please refer to FIG. 5. The centre rod 23 is a solid rod but has a central hole 232 formed at its front portion for receiving an inner rod 233 therein. The inner rod 233 has a side hole 234 at a middle portion thereof for receiving a spring 235 and a spring key 236 therein. The spring key 236 has a substantially triangular top piece having one single backward and downward inclined surface and is springily retractable in the side hole 234. An elongated through hole 237 is formed on the wall of the central hole 232 corresponding to the spring key 236 so as to allow the spring key 236 to project out of the centre rod 23 and to limit the displacement of the spring key 236. A slit 238 is provided on top of the inner rod 233, and a pin 239 transversely passes through the front head 231 of the centre rod 23 and the slit 238 to retain the inner rod 233 in the central hole 232. Then, a C-ring 230 is engaged with a preformed annular groove on the front head 231 to fix the pin 239 in place. Finally, an inner hexagon screw 3 is screwed to the top of the central hole 232 over the inner rod 233 and thereby retains the inner rod 233 in the centre rod 23. 
     Due to the backward and downward inclined surface and the retractility of the spring key 236, as well as the front head with larger outer diameter, the centre rod 23, when being inserted in the coupling 21 with the rear end thereof passing through the middle partition 211 and extending into the rear portion of the coupling 21, will be retained inside the coupling 21. After extending through the coupling 21, the threaded rear end of the centre rod 23 passes through the sliding block 22 and engages with the connection member 24. The spring 25 is put over a rear end of the connection member-24 and the push member 26 is further put over the spring 25 with its front end screwed to the rear end of the sliding block 22 so that the push member 26 may push the sliding block 22 to move. The inner hexagon screw 27 is internally screwed to the rear end of the push member 26 to abut against the rear end of the spring 25. The adjustment of the position of screw 27 in the push member 26 may adjust the spring force of the spring 25 lest the spring 25 should fatigue and deform after a long period of use. The sleeve 29 has a front end with internal threads for the sleeve 29 to screw to the externally threaded rear end of the coupling 21 and receive a part of the push member 26 and thereby prevents the push member 26 from loosely swaying. The second connection piece 28 is screwed at one end to the rear end of the push member 26 and at the other (rear) end to a handle 4 or other member, depending on the actual need, as shown in FIG. 6. 
     Please refer to FIG. 2 which shows a powder-actuated anchor shooter of the present invention in a state of ready for use. When the push member 26 is gradually pushed forward, the sliding block 22 is caused to move forward and the spring 25 is compressed to store larger spring force. When the sliding block 22 is moved to contact the spring key 236 of the centre rod 23, the spring key 236 is springily depressed into the centre rod 23 and the centre rod 23 is no longer retained behind the middle partition 211 of the coupling 21 by the spring key 236. At this point, the compressed spring 25 with largely stored energy of movement shall instantaneously thrust the centre rod 23 forward, causing the front head 231 of the centre rod 23 to strongly impact upon the hammer 14, which in turn contacts the powder pack 172 and causes the same to explode. The pressure produced by the explosion of powder pack 172 is immediately sent into the shooting assembly 13 to powerfully thrust the piston rod 133 which in turn thrusts a anchor 5 loaded in front of the head member 132 and the anchor 5 is thereby shot and implanted into the wall or the target, as shown in FIG. 3. 
     Please further refer to FIG. 4. When the powder pack 172 explodes, the shooting assembly 13 is pushed forward for a certain distance which is limited by the screw 16. When a second anchor 5 is loaded, the shooting assembly 13 is pressed to a position ready for the next thrust. When the push member 26 is pushed, the shooting assembly 13 forms a buffer distance and thrusts backward, thereby, the restoring bar 143 backward pushes the hammer 14 to the original position for the next impact. 
     FIG. 6 shows an embodiment of the present invention. A handle or grip 4 may be screwed to the rear end of the second connention piece 28. When the grip 4 is used together with the front grip 111 of the main body 11, the anchor shooter of the present invention can be conveniently held as a rifle to firmly shoot the anchor 5 at a short distance or at a special angle.