Abstract:
A setting tool for driving in fastening element includes a bolt guide ( 12 ) axially displaceably arranged in the tool housing ( 11 ), a magazine ( 15 ) projecting sidewise from the bolt guide ( 12 ) and displaceable in a direction opposite the setting direction ( 40 ) against a biasing force of a first spring ( 22 ) relative to the bolt guide ( 12 ), a second spring located between the housing ( 11 ) and the magazine ( 15 ) and having a maximal biasing force acting in the setting direction ( 40 ) and an excursion greater than a maximal biasing force and an excursion of the first spring ( 22 ); and an annular element ( 23 ) which surrounds the piston guide ( 13 ) of the tool and is located in a receiving space ( 20 ) formed in the housing ( 11 ) for transmitting a biasing force of the second spring ( 21 ) to at least one engagement surface ( 19 ) provided on the magazine ( 15 ).

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a setting tool, in particular, to an expandable gas-driven setting tool for driving fastening elements, such as bolts, nails and the like in a constructional component and including a housing, a bolt guide axially displaceably arranged in the housing, a magazine for the fastening elements projecting sidewise from the bolt guide and displaceable in a direction opposite the setting direction against a biasing force of a first spring relative to the bolt guide, a second spring located between the housing and the magazine and having a maximal biasing force acting in the setting direction and an excursion greater than a maximal biasing force and an excursion of the first spring, and a piston guide axially displaceably arranged in the housing.  
           [0003]    2. Description of the Prior Art  
           [0004]    European Publication EP-0 743 141 B1 discloses an explosive powder charge-operated setting tool having a housing and an axially displaceable bolt guide arranged in the housing and projecting beyond the housing in a setting direction. A magazine for fastening elements is suspended sidewise from the bolt guide. The magazine is displaced relative to the bolt guide in a direction opposite the setting direction against a spring-biasing force. The magazine provides for storing of a plurality of fastening elements, such as bolts or nails, which are located in guide sleeves connected with each other in a belt-like manner, and for advancing of the fastening elements into the bolt guide. The fastening elements are displaced in a direction toward the bolt guide with a spring-biased slide located in the magazine. On the magazine, there is provided a pin that is supported against the magazine with a spring and is pressed toward the tool housing when the setting tool is pressed against a constructional component. The bolt guide is so displaced that the displacement of the fastening elements is blocked. The maximal biasing force applied to the pin and the corresponding spring excursion of the spring are greater than the spring-biasing force and excursion of a spring located between the bolt guide and magazine. This is necessary to insure the forward movement of the fastening elements located in the magazine.  
           [0005]    For actuating the setting tool, the housing should be displaced relative to the bolt guide over a certain so-called “press-on path.” To this end, in a first stage of the press-on displacement, a setting direction-side, press-on surface of the bolt guide is set against a constructional component, and the housing is pressed in the setting direction. During the press-on step, the magazine is displaced in the setting direction relative the bolt guide until the magazine abuts the constructional component. The spring, which is arranged between the housing and the magazine, reaches during the first press-on phase or stage, the setting direction-side, end surface of the housing and displaces the magazine, because of its greater biasing force and excursion, relative to the bolt guide in the setting direction until the magazine contacts the constructional component. At the same time, the spring, which is located between the bolt guide and the magazine, becomes preloaded. In this position of the magazine, the advancement of the fastening elements from the magazine into the bold guide is prevented. After the setting process, when the setting tool is lifted off the constructional component, first, the magazine, the bolt guide, and the piston guide are displaced together relative to the housing. Only, when the magazine and the bolt guide have been displaced relative to the housing so far that the spring or the pin does not contact the housing anymore, the displacement of the magazine relative to the bolt guide takes place under the biasing force of the spring arranged between the bolt guide and the magazine, until the magazine reaches its initial position. In this way, the lifting off the displacement blocking means takes place with a time delay.  
           [0006]    The drawback of the known setting tool consists in that the pin, which is not arranged coaxially with the press-on direction, applies a torque to the displacement parts, in particular to the magazine. This leads to an asymmetrical load and, as a result, to jamming of the movable parts.  
           [0007]    Accordingly, an object of the present invention is to so modify a setting tool of the type discussed above that a reliable forward displacement of the fastening elements is insured, and the above-noted drawbacks are eliminated.  
         SUMMARY OF THE INVENTION  
         [0008]    This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing, on the magazine, at least one engaging surface that at least partially surrounds the bolt guide, and by providing an annular element circumferentially surrounding the piston guide and located in a receiving space formed in the housing for transmitting a biasing force of the spring which is located between the magazine and the housing to the at least one engagement surface of the magazine upon the setting tool being pressed against the constructional component.  
           [0009]    The annular element is arranged coaxially with the press-on or setting direction.  
           [0010]    These novel features of the present invention permits to pivot the magazine with the bolt guide by 360° as its cooperation with the annular element and, thereby, a forward advancement is possible in any pivotal position. Further, the application of force to the movable parts during the press-on stage takes place symmetrically, which prevents jamming of the movable parts, and no decrease of the press-on force because of jamming takes place.  
           [0011]    The annular element, which is guided in the front, setting direction-side, of the housing, is biased in the setting direction by a compression spring likewise coaxially arranged with respect to the setting direction. The compression spring is supported against the housing or a sleeve fixedly secured in the housing.  
           [0012]    Advantageously, the receiving space is formed as a socket in which both the annular element and compression spring are arranged. A stop in the housing can prevent the annular element from falling out of the housing. These measures permit to provide a compact and easy to assemble setting tool.  
           [0013]    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  
       [0014]    The drawings show:  
         [0015]    [0015]FIG. 1 a side, partially cross-sectional view of a setting tool according to the present invention in its initial position;  
         [0016]    [0016]FIG. 2 a bottom, partially cross-sectional view of the setting tool show in FIG. 1;  
         [0017]    [0017]FIG. 3 a side, partially cross-sectional view of the setting tool shown in FIG. 1 in a first partially press-on position;  
         [0018]    [0018]FIG. 4 a side, partially cross-sectional view of the setting tool shown in FIG. 1 in a second partially press-on position;  
         [0019]    [0019]FIG. 5 a bottom, partially cross-sectional view of the setting tool of FIG. 1 in a second partially press-on position; and  
         [0020]    [0020]FIG. 6 a bottom, partially cross-sectional view of the setting tool of FIG. 1 in a completely press-on position. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    A setting tool  10  according to the present invention, which is shown in FIGS.  1 - 2  in its initial position, has a housing  11 , a bolt guide  12  projecting beyond the housing  11  tin a setting direction  40 , and a handle  31  extending downward from the housing. On the handle  31 , there is provided an actuation switch  32  or trigger for initiating a setting process.  
         [0022]    The setting tool  10  can be driven, e.g., with propellant charges arranged on a displaceable carrier strip, not shown in the drawings. E.g., with the setting tool being arranged on a mount, the housing  11  can also have two, movable relative to each other parts.  
         [0023]    A magazine  15  for fastening elements  18  and displaceable in an axial direction is arranged on the bolt guide  12 . The fastening elements  18  are carried by a belt-shaped magazine strip  16 , with the fastening elements  18  being arranged in respective separate guide elements  17 . The displacement of the fastening elements  18  in a direction toward the bolt guide  12  takes place in the magazine  15  automatically by a spring-biased transportation carriage, not shown, displaceable along a guide in the magazine  15 . The fastening elements  18  are advanced from the magazine  15  into the bolt guide  12  through a side opening  14 . In the housing  11 , there is further provided a displaceable piston guide  13  that is supported in the housing  11  by a spring  27 . A percussion piston, not shown, is displaceably arranged in the piston guide  13 . The percussion piston drives a fastening element  18  in a constructional component after actuation of the switch  32  and ignition of a propellant charge.  
         [0024]    The magazine  15  is so formed that it circumferentially surrounds the bolt guide  12  at least regionwise. At the end of the magazine  15  adjacent to the housing  11 , there is provided an engagement surface  19  that is formed as annular surface, at least regionwise, and that surrounds the setting direction end of the piston guide  13 . The engagement surface  19  can be completely circular or be regionwise interrupted. The function of the engagement surface  19  will be explained in detail further below.  
         [0025]    In a recess of the magazine  15  adjacent to the bolt guide  12 , there is arranged a spring  22  supported at its opposite ends against the magazine  15  and a projection  25  provided on the bolt guide  12 . The bolt guide  12  has another projection  26  which is supported, in the initial position of the setting tool  10 , against a stop surface  30  of the magazine  15 , as shown in FIG. 1. The spring  22  biases the projections  25 ,  26  against the respective stop surfaces  30 ′  30  of the magazine  15 .  
         [0026]    The front, in the setting direction  40 , end surface of the bolt guide  12 , defines a press-on surface  28  that is pressed against a constructional component U. The bolt guide  12  is further provided with a locking edge  29  located at the end of the opening  14  through which a fastening element  18  is advanced into the bolt guide  12 . The locking edge  29  can prevent the displacement of the fastening element  18  and of the magazine strip  16  even in a completely press-on condition of the setting tool  10 , as it will be explained in detail further below. The magazine  15  can be connected with the bolt guide  12  without a possibility of rotation relative thereto, and the unit formed of bolt guide  12  and the magazine  15  can be rotated with respect to the piston guide  13 . In this case, it becomes possible to displace the magazine  15  with respect to the handle  31  of the setting tool  10 , e.g., by 180°.  
         [0027]    At the setting direction end of the housing  11 , there is provided a cylindrical receiving space  20  defining, at its end adjacent to the housing  11 , a support surface  24  against which a second spring  21  is supported. The second spring  21  that surrounds the piston guide  13  and a spring  27  which circumferentially surrounds the piston guide  13 . The front end of the second spring  21  is closed with an annular element  23  displaceably arranged in the receiving space  20 .  
         [0028]    The annular element  23  can be pressed into the receiving space  20  against a biasing force of the spring  21 .  
         [0029]    To make the actuation of the setting tool  10  possible, the bolt guide  12  and the piston guide  13 , which adjoins the bolt guide  12 , should be displaced relative to the housing  11  over a press-on path A 1  through A 3  in order to cock the ignition device, not shown, which is arranged in the rear of the housing  11  and to be able to actuate the switch  32 . To this end, as shown in FIG. 3, the press-on surface  28  of the bolt guide  12  is set against the constructional component U, and the housing  11  is pressed against the constructional component U in the setting direction  40 . In FIG. 3, the setting tool  10  has already been displaced over a press-on path A 1  against the construction component U (see FIGS. 1 and 2). The press-on path A 1  is defined by a distance between an engagement surface  19  and a stop surface  33 . With the setting tool  10  being displaced over the press-on path A 1 , the piston guide  13  is displaced against the biasing force of the spring  27  into the housing  11 , with the spring  27  being compressed by a respective length. In this position of the setting tool  10 , the position of the bolt guide  12  with respect to the magazine  15  remains unchanged. The annular element  23  only engages, with its setting direction stop surface  33 , the engagement surface  19  of the magazine  15  under action of the biasing force of the spring  21 .  
         [0030]    In FIGS.  4 - 5 , the setting tool  10  is displaced further over a press-on path A 2  in the setting direction  40  and remains pressed against the constructional component U. In this position of the setting tool  10 , the bolt guide  12  is displaced relative to the magazine  15  by the biasing force of the spring  22 . As a result, the locking edge  29  is so displaced (see FIG. 5) that it prevents displacement of the magazine strip  16  or the guide elements  17  as it overlaps the end  34  of the uppermost guide element  17 . At that, the initial condition of the spring  21  remains unchanged as the biasing force of the spring  21  is greater than that of spring  22 .  
         [0031]    In FIG. 6, the setting tool  10  is displaced further over a distance A 3  in the setting direction  40  against the constructional component U. Upon displacement of the setting tool  10  over the path A 3 , the annular element  23  is displaced against the biasing force of the  21  into the receiving space  20  in the housing  11 . Only in the position of the setting tool  10  shown in FIG. 6, the setting process can be initiated by the actuation of the switch  32 . When the setting tool  10  is lifted off the constructional component U, the springs  21 ,  22 ,  27  act in a reverse, in comparison with the press-on step, order, displacing the corresponding components of the setting tool  10  in the setting direction  40 .  
         [0032]    Upon lifting off the setting tool  10  over the path A 3 , the magazine  15  is pressed away from the housing  11  by the annular element  23  and the spring  21  that applies a biasing force to the annular element  23  into the position shown in FIGS.  4 - 5 . The displacement of the magazine strip  15  in this position of the setting tool  10  is prevented as the locking edge  29  of the bolt guide  12  is located between two guide elements  17 , so that the displacement of the magazine strip  17  is blocked. Thus, the forward movement of the magazine strip  16 , during the lifting of the setting tool  10 , is prevented. If the magazine  15  and the bolt guide  12  are pivoted with respect to the piston guide  13  by 180°, when the unit of the magazine  15  and the bolt guide  12  is pivotally arranged relative to the piston guide, this effect is still available. This is because a contact between the annular element  23  and the engagement surface  19  of the magazine  15  is insured due to the annular shape, at least regionwise, of the engagement surface  19  and the annular element  23 .  
         [0033]    Only after the setting tool  10  has been lifted over the path A 2  to the position showing FIG. 3, the locking edge  29  is displaced out of the displacement path of the magazine strip  19 . The bolt guide  12  is displaced relative to the magazine  15  by the spring  22 , so that the projections  25 ,  26  again abut the stop surfaces  30 ′,  30  of the magazine  15 , respectively.  
         [0034]    Upon a complete lifting of the setting tool  10  over the path A 1 , the setting tool  10  returns into its initial position shown in FIGS.  1 - 2 .  
         [0035]    Though the present invention was shown and described with references to the preferred embodiment, such is merely illustrative of the present invention and is not to be construed as a limitation thereof and various modifications 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.