Abstract:
An explosive powder charge-operated setting tool for driving fastening elements in a constructional component includes a propellant-driven setting mechanism, an ignition element ( 23 ) for igniting a propellant ( 71 ) received in the propellant receptacle ( 18 ) of the setting mechanism, and a transporting device ( 30 ) for displacing a propellant magazine in a guide channel ( 22 ) and including elements operable by the ignition element ( 23 ) for displacing the transporting device from a first position in which the transportation of propellants is prevented, into a second position in which at least partial transportation of the propellants is possible.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of Invention  
         [0002]     The present invention relates to a combustion power-operated setting tool such as an explosive powder charge-operated setting tool for driving fastening elements in a constructional component and including a propellant-driven setting mechanism including a propellant receptacle for receiving a propellant, ignition means for igniting the propellant received in the propellant receptacle, a guide channel for receiving a propellant magazine, and a transporting device for displacing the propellant magazine in the guide channel.  
         [0003]     2. Description of the Prior Art  
         [0004]     The setting tools of a type described above operate, mostly, with solid fuels in form of cartridges filled with the explosive powder or in form of pellets made of compressed explosive powder. The setting mechanism of these setting tools includes a piston guide which is at least partially arranged in the tool housing, and a setting piston axially displaceable in the piston guide. The setting piston of these setting tools is driven by combustion gases of the fuel. The setting piston drives fastening elements, such as nails, bolts, etc. in the constructional components. After completion of a setting process, the setting piston should be returned to its initial position. The propellants are fed to the propellant receptacle in the setting tool, e.g., in form of a magazine strip. As a rule, after completion of a setting process, the magazine strip, which is displaced in a guide channel, is displaced by a transporting mechanism by one cartridge.  
         [0005]     German Publication DE 30 359 28 A1 discloses a combustion power-operated setting tool in which the cartridges are displaced by a mechanism that is actuated upon the setting tool being pressed against a constructional component. The transportation of the cartridges, however, is blocked if the setting tool, upon having been pressed against a constructional component, is not actuated. The blocking can, however, be released upon actuation of overriding means, e.g., in order to unload the setting tool. The transporting mechanism includes a transporting slide that is arranged on the displaceable in the housing piston guide in the region of the cartridge socket. The transporting slide is connected by a lever with a transporting pawl that engages the magazine strip.  
         [0006]     The drawback of the known setting tool consists in that the cartridge, which is located in the cartridge socket, is transported further even when the cartridge is not ignited after actuation of the setting tool. A new actuation attempt with the same cartridge is not possible.  
         [0007]     Accordingly, an object of the present invention is to provide a setting tool in which the drawback of the known combustion power-operated setting tool is eliminated.  
         [0008]     Another object of the present invention is to provide a setting tool in which a reliable transportation of cartridges during a setting process is insured.  
       SUMMARY OF THE INVENTION  
       [0009]     These and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a setting tool of the type described above and the transporting device of which includes means operable by the ignition means for displacing the transporting device from a first position in which the transportation of propellants is prevented, into a second position in which at least partial transportation of the propellants is possible. For operating the displacing means, an ignition displacement of the ignition means, e.g., of a firing pin is used when it is advanced toward a propellant located in the propellant receptacle. This insures that a non-consumed propellant can only then be completely transported up to the propellant receptacle or be at least partially transported toward the propellant receptacle when the ignition means actually strikes, after actuation of the setting tool, the propellant in the propellant receptacle. In case when the ignition means is not displaced, the transportation device is not released so that the same propellant would be enclosed in the propellant receptacle when the setting tool is pressed against a constructional component anew. A non-consumed propellant would not be automatically transported.  
         [0010]     Advantageously, the transporting device includes transporting spring means for biasing the propellant magazine, e.g., a propellant strip or a cartridge strip, which is received in the guide channel, in a transporting direction. The spring means provides for a technically simple displacement of the propellant magazine.  
         [0011]     It is further advantageous when the transporting device displacing means includes at least one locking member and a spring for biasing the at least one locking member in a direction toward the guide channel into a position in which transportation of the propellant is blocked. The locking member fixes the magazine or the propellant strip in its position in the guide channel until the locking member is actuated. Advantageously, the locking member cooperates with recesses provided on a side of the propellant strip. The side recesses permit to control in a simple manner the displacement of the propellant strip by the transporting spring means.  
         [0012]     Advantageously, the transporting device includes at least one actuator for displacing the at least one locking member against a spring-biasing force of the biasing spring from the position in which the transportation of the propellants is blocked, into a position in which the transportation of the propellants becomes possible. Thus, the actuator controls the operation of the locking member.  
         [0013]     Advantageously, the at least one actuator is displaced by the ignition means from a release position in which displacement of the at least one locking member by the actuator is prevented, into an actuation position in which the displacement of the at least one locking member by the actuator becomes possible. If a further actuator is provided, it can be controlled exclusively by the press-on mechanism of the setting tool. In this way, the transporting device can be controlled or at least partially controlled in a simple manner. It can further be advantageous to provide the ignition means with a control element for displacing the at least one actuator from its release position into its actuation position upon displacement of the ignition means after actuation of the setting tool, from an ignition-ready position of the ignition means into its ignition position.  
         [0014]     Advantageously, the transporting device displacing means includes two locking members axially offset relative to each other and arranged on opposite sides of the guide channel. With two locking members, the transportation path of the transporting device can be divided in two parts or sections.  
         [0015]     For effecting a complete transporting sequence for displacing a new propellant in a position coaxial with the propellant receptacle and, optionally for a complete transporting sequence for displacing a burnt-up propellant out of a position coaxial with the propellant receptacle, actuation of both locking members one after another is necessary.  
         [0016]     Advantageously, the locking members are formed as pawls pivotally supported on respective pivot supports. This permits to reduce the actuation force and the actuation path of the actuators.  
         [0017]     It is further advantageous when the pivot supports are secured to the guide housing for the ignition means. This permits to obtain a compact structure.  
         [0018]     The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiment when read with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     The drawings show:  
         [0020]      FIG. 1 a  partially cross-sectional view of a section of a combustion power-operated setting tool according to the present invention in an initial position of the setting tool;  
         [0021]      FIG. 2 a  cross-sectional view of the setting tool along line II-II in  FIG. 1 ;  
         [0022]      FIG. 3 a  cross-sectional view of the setting tool along line III-III in  FIG. 1 ;  
         [0023]      FIG. 4 a  cross-sectional view of the setting tool according to  FIG. 3  in a partially pressed-on condition;  
         [0024]      FIG. 5 a  longitudinal cross-sectional view of a section of the setting tool showing a detailed view of the ignition unit;  
         [0025]      FIG. 6 a  cross-sectional view of the setting tool according to  FIG. 2  in a completely pressed-on condition;  
         [0026]      FIG. 7 a  cross-sectional view of the setting tool according to  FIG. 3  in a completely pressed-on condition;  
         [0027]      FIG. 8 a  cross-sectional view of the setting tool according to  FIG. 3  in a release condition;  
         [0028]      FIG. 9 a  cross-sectional view of the setting tool according to  FIG. 2  in its partially lifted-off condition; and;  
         [0029]      FIG. 10 a  cross-sectional view of the setting tool according to  FIG. 3  in its partially lifted-off condition. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]     A combustion power-operated setting tool  10  according to the present invention, which is shown in  FIGS. 1 through 10 , includes a one-or multi-part housing  11 , and a piston guide  13  which is displaceably arranged in a receiving chamber  24  of the housing  11  and is supported in the housing  11  by a spring  17  that biases the piston guide  13  in a setting direction. A setting piston  15  is axially displaceably arranged in a guide chamber  14  of the piston guide  15 . In the piston guide  13 , there is provided a propellant receptacle  18  which is formed as a cartridge socket for receiving propellants  71 , e.g., cartridges with which the setting piston  15  is driven. An ignition unit  20  serves for ignition of a propellant  71  that is received in the propellant  71  that is received in the propellant receptacle  18  (see, in particular,  FIG. 1 ). As particular shown in  FIG. 5 , the ignition unit  20  includes ignition means  23  which is displaceable in a firing pin guide  21  and which is formed as a firing pin. The ignition means  23  is biased in the ignition direction by a spring  25 .  
         [0031]     On the housing  11 , there is provided, in the embodiment shown in the drawings, a handle  12  that carries an actuation switch  19  for actuating the ignition unit  20  and thereby the setting process. The actuation switch  19  is actuated by a user of the setting tool  10 .  
         [0032]     Cartridges with propellants  71  are stored in a propellant magazine which is formed as a propellant strip  70  displaceable in a guide channel  22  by a transporting device  30 . The transporting device  30  has a transporting spring element  39  which is formed as a scroll spring having its free end secured at a point  29  to the housing  11  in the region adjacent to the ignition unit  20  and the receiving chamber  24 . Upon displacement the propellant strip  70  in the guide channel  22  in a direction opposite the transporting direction  63 , the transporting spring element  39  becomes tensioned and biases the propellant strip  70  in the transporting direction  63 . The transporting device  30  further includes two opposite, offset relative to each other locking members  31 ,  32  arranged on opposite sides of the guide channel  22  and formed as pawls. The locking members  31 ,  32  are pivotally arranged on respective pivot support  35 ,  36  provided in a guide housing  28  of the ignition unit  20 . Two springs  33 ,  34  bias the respective locking members  31 ,  32  toward the guide channel  22 , as particularly shown in  FIGS. 2, 6 , and  9 . In the initial position of the setting tool  10 , which is shown in  FIGS. 1-3 , the locking member  31  engages in a side recess  73  of the propellant strip  70 , whereas the second locking member  32  engages an elevation between two recesses  72  provided on opposite side of the propellant strip  70 . Both locking members  31 ,  32 , thus, project into the guide channel  22  (see, in particular,  FIGS. 2-3 ). Both locking members  31 ,  32  have each an actuation section  37 ,  38  formed as inclination surface means. The actuation sections  37 ,  38  cooperate with respective adjusting sections  47 ,  48  of respective actuators  41  and  42 .  
         [0033]     The first actuator  41 , which is formed as a pin, is arranged on the same side of the setting tool as the locking member  31  and is secured on the piston guide  13 . The adjusting section  47 , which is formed as an inclination surface, is provided at a free end of the actuator  41  and is spaced, in the initial position of the setting tool  10  shown in  FIGS. 1-3 , from the actuation section  37  of the respective locking member  31 . The actuator  41  is displaceably arranged in a guide  45  provided in the guide housing  28  of the ignition unit  20 . The actuator  41  is displaceable against a biasing force of a spring  43 .  
         [0034]     The second actuator  42 , which is also formed as a pin, is arranged on the same side of the setting tool  10  as the locking member  32 . The actuator  42  is displaceably arranged in a guide  46  provided in the guide housing  28  of the ignition unit  20 , and is displaceable against a biasing force of a spring  44 . The adjusting section  48  of the actuator  42  is formed as a blade-shaped projection. In the initial position shown in  FIGS. 2-3 , the actuator  42 , together with its adjusting section  48 , is located in its release position  50  in which the adjusting section  48  is pivoted out from the axial projection of the actuation section  38  of the locking member  32 . An actuation of the locking member  32 , with the adjusting section  48  of the actuator  42  acting on the actuation section  38 , is not possible in the position  50  of the actuator  42 .  
         [0035]     On the ignition means  23 , there is provided a control element  26  having a control section  27 . Upon displacement of the ignition means  23  toward the propellant receptacle  18  in the setting direction  60 , the control section  27  displaces the actuator  42 , together with its adjusting section  48 , in a manner of a link control, from its release position  50  in its actuation position  51  in which the adjusting section  48  is pivoted into the axial projection of the actuation section  38  of the locking member  32 , as will be explained in more detail further below.  
         [0036]      FIG. 4  show the setting tool  10  in a condition in which it is partially pressed with its mouth portion against a constructional component (not shown). In this position of the setting tool  10 , the piston guide  13 , together with the actuator  41 , is displaced in a direction  61  opposite the setting direction toward the ignition unit  20 . The adjusting section  47  of the actuator  41  acts on, applies pressure to the actuation section  37  of the locking member  31 , lifting it, against the biasing force of the spring  33  (not shown in  FIG. 4 , see  FIG. 2 ), off its locking position in the recess  73  of the propellant strip  70 .  
         [0037]     As a result, the propellant strip  70  is displaced in the transporting direction  63  by the transporting spring  39  (see  FIG. 1 ) until the locking member  32  engages, under the biasing force of the spring  34 , in the next recess  72  of the propellant strip  70  (see  FIG. 4 ). Now, the propellant strip  70  is located in a position in which a new propellant  71  is arranged coaxially with the propellant receptacle  18 .  
         [0038]     With the setting tool  10  being further pressed against the constructional component, an actuator (not shown), which is provided on the piston guide  13  preloads the ignition means  23 , displacing it into its ignition position, as shown in  FIG. 5 .  
         [0039]      FIGS. 6-7  show the setting tool  10  in a position in which it is completely pressed against the constructional component. As a result of further displacement of the piston guide  13  in the direction  61 , the propellant  71  is pushed into the propellant receptacle  18 , becoming enclosed herein, as particularly shown in  FIG. 7 . The locking member  31  still remains in its lifted off position in which it is held by the actuator  41 . The second locking member  32  meanwhile engages in the recess  72 . The actuator  42 , together with its adjusting section  48 , remains in its release position  50 , and the transporting device  30  remains, thus, in a position in which transportation of propellants is prevented.  
         [0040]      FIG. 8  shows the setting tool  10  in a position in which the ignition has taken place, as shown by a burnt-up propellant  71   b . To this end, upon actuation of the actuation switch  19  (see  FIG. 1 ), the ignition means  23  strikes the propellant  71 , igniting the same, upon being displaced by the biasing force of the spring  25  (see  FIG. 5 ). With this, the control section  27  of the control element  26  engages the adjusting section  48  of the actuator  42 , displacing the actuator  42  in its actuation position  51 , shown in  FIGS. 8-10 , and in which the adjusting section  48  lies in the axial projection of the actuation section  38  of the locking member  32 . The position of the first locking member  31  remains unchanged.  
         [0041]      FIGS. 9-10  show the setting tool  10  in a condition in which it is almost completely lifted off the constructional component. In this position of the setting tool  0 . 10 , the piston guide  13  and the actuator  41 ,  42  are displaced in the setting direction  60  away from the ignition unit  20 . As a result, the actuator  41  releases the locking member  31 , which is pivoted by the spring  34  in the guide channel  22  in the direction toward the propellant strip  70  and which engages an elevation between two recesses  73  in the propellant strip  70 . Immediately thereafter, the adjusting section  48  of the actuator  42  acts on the actuation section  38  of the locking member  32 , pivoting the locking member  32  out of the recess  72 . In this position of the transporting device  30 , the propellant strip  70  is transported by the transporting spring  39  (see  FIG. 1 ) further forward until the locking member  31  engages in the next recess  73 . The propellant strip  70  occupies an intermediate position, shown in  FIGS. 9-10 , in which enclosure of the next, non-burnt-up propellant  71  in the propellant receptacle  18  is not possible as the propellant  71  is not coaxially aligned with the propellant receptacle  18 .  
         [0042]     Upon a complete lifting of the setting tool  10  of the constructional component, the actuator  42  is displaced, with link control means, not shown, from its actuation position  51  in its release position  50  in  FIG. 2 , and the setting tool  10  is returned into its initial position. Actuation of the locking member  32  is not possible without a new actuation of the ignition means  23 .  
         [0043]     In the inventive setting tool  10 , transportation of the propellants is reliably prevented even when the actuation switch  19  is actuated but the ignition means  23  or the fire pin does not strike the propellant  71 . The actuator  42  is not displaced, at that, in its actuation position, and the locking member  32  is not lifted off the respective recess  72 , even upon the setting tool being again lifted off the constructional component.  
         [0044]     Further, the inventive setting tool can be provided with a simple detection device that would prevent a press-on process when the presence of a fastening element in the bolt guide of in the magazine of fastening elements is not detected. In this case, the actuator  41  would not lift the locking member  31  off the recess  73  in the propellant strip  70 , and the propellant strip cannot be displaced further.  
         [0045]     The setting tool according to the present invention can further be provided with means for manual lifting of the locking members  31 ,  32  off the guide channel, so that the propellant strip  70 , which is located in the guide channel  22 , can be removed from the tool even when the strip is not completely spent.  
         [0046]     Though the present invention was shown and described with reference to the preferred embodiment, such is merely illustrative of the present invention and is not to be construed as a limitation thereof and various modification of the present invention will be apparent to those skilled in the art. It is therefore not intended that the present invention be limited to the disclosed embodiment or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims.