Abstract:
A fluid-fuel operated setting tool for driving in fastening elements includes a housing ( 11 ) with a combustion chamber provided therein for combusting fluid fuel, with a released energy of combustion of the fluid being used for driving in a fastening element, and a reservoir ( 20, 20′, 20″ ) for storing the fluid fuel and attached to the tool housing and having, in a direction parallel to its longitudinal axis ( 22 ), a jacket ( 21 ) shape and habit of which are defined by inscribed and circumscribing envelope circles ( 211, 212 ), with the cricumscribing envelope circle having a size of its circumference greater than the size of the circumference of the insribed envelope circle.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a fluid fuel-operated setting tool for driving-in fastening elements and including a housing with a combustion chamber provided therein for combusting fluid fuel, with a released energy of combustion of the fluid fuel being used for driving in a fastening element, and a reservoir for storing the fluid fuel and from which the fluid fuel is fed to the combustion chamber and mounted on the housing. 
     2. Description of the Prior Art 
     Setting tools of the type described above are disclosed, e.g., in German Publication DE-198 53 555 A1 and U.S. Pat. No. 4,403,722. In the known setting tools, the tool-operating fuel is stored in elongated cylindrical containers or reservoirs which are arranged in the housing of setting tools. The gaseous or liquid fuel is fed to the combustion chamber by using a metering valve. The energy, which is released upon combustion of the fuel, is used, at least partially, for driving a piston that drives a to-be-set nail, pin, etc. . . . in a substrate. 
     The possibilities of arrangement of the fuel containers or fuel reservoirs on setting tools are rather limited because of the shape of the containers and reservoirs. German Publication DE-198 53 555 A1 discloses an arrangement of a fuel container in the handle of a setting tool. The drawback of this arrangement consists in that because of a limited available space in the handle, the fuel container or cartridge cannot exceed a certain size. In setting tool with a large power stage, the fuel consumption is very high, and the container or cartridge should be replaced after a very short use of the setting tool. 
     U.S. Pat. No. 4,403,722 discloses a setting tool in which a fuel reservoirs, which is formed as an elongate cylinder is arranged between the combustion space and the handle. This arrangement, in addition to a limited fuel supply, has a drawback which consists in that because of an increased distance between the handle and center of gravity of the setting tool, this setting tool is difficult to handle. 
     Accordingly, an object of the present invention is to provide a setting tool of the type described above in which the drawbacks of the conventional setting tools are eliminated, and the setting tool has a compact design. 
     SUMMARY OF THE INVENTION 
     This and other objects of the present invention, which will become apparent herein after are achieved by providing a fluid-fuel operated setting tool of the type described above in which the fuel reservoir has, in a direction parallel to its longitudinal axis, a jacket shape and habit of which are defined b inscribed and circumscribed, substantially similar envelope circle, with the fuel reservoir being so formed that in a direction perpendicular to the longitudinal axis of the fuel reservoir, the jacket envelope defining, inscribed and circumscribing envelope circles stay in relationship such that a size of a circumference of the circumscribing envelope circle is greater than a size of a circumference of the inscribed envelope circle, preferably in more than two times, as a result, a width of the fuel reservoir exceeds the reservoir height in more than two times. 
     The fuel reservoir according to the present invention is formed, with respect to its inner space of convex and/or concave jacket sections which can be adapted to the respective outer surface of the tool housing, so that the reservoir can be harmoniously adapted to the shape of the tool housing. 
     The fuel reservoir jacket can be formed of straight and bent sections and have one or more edges. A reservoir with such a jacket can be arranged in the setting tool or outside of the setting tool in which to this end, a spandrel can be provided. This is possible because a reservoir can be adapted to a geometry of the tool housing. 
     Advantageously, the reservoir is releasably mounted on the setting tool, and is reversibly secured thereto with appropriate connection means. This permits an easy and quick replacement of the reservoir. 
     Advantageously, the reservoir is provided with a contact surface that permits to formlockingly support the reservoir on the tool housing. This insures an easy access to the reservoir and provides for a favorable visual impression. 
     Advantageously, the connection or mounting means provides for a releasable connection of the reservoir with the fuel feeding conduit in the tool housing. 
     Advantageously, the fuel reservoir is mounted on a periphery of a central housing section in a spaced relationship to a handle of the setting tool, with the longitudinal axis of the fuel reservoir extending parallel to a longitudinal axis of the setting tool. The arrangement of the reservoir in a spaced relationship to the handle provides sufficient space for the user to conveniently grip the handle, which facilitates handling of the setting tool. The arrangement of the reservoir along an axis parallel to the setting tool axis provides for a favorable location of the center of gravity of the tool with the mounted reservoir. 
     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 embodiments, when read with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the Drawings: 
     FIG. 1 shows a perspective view of a first embodiment of a setting tool according to the present invention with a fuel reservoir mounted on the setting tool; 
     FIG. 2 shows a perspective view of a second embodiment of a setting tool according to the present invention with a mount provided on the setting tool for receiving a fuel reservoir; 
     FIG. 3 shows a rear view of a third embodiment of a setting tool according to the present invention with a fuel reservoir arranged between the tool handle and the tool housing; 
     FIG. 4 shows a schematic view of a fourth embodiment of a setting tool according to the present invention with a fuel reservoir arranged between the tool handle and the tool housing in a spandrel; 
     FIG. 5 shows a cross-sectional view of the fuel reservoir shown in FIG. 4; and 
     FIG. 6 shows a cross-sectional view of a fuel reservoir shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first embodiment of a setting tool  10  and a fuel reservoir  20  according to the present invention are shown, as discussed above, in FIGS. 1 and 6. The setting tool  10  has a housing  11  in which the tool mechanics and, if necessary, the tool electronics, in particular for controlling the fuel delivery and the ignition of the fuel contained in the combustion chamber, are located. On the housing  11 , there is provided a handle  15  with a trip switch  16  for actuating the setting tool and starting the setting process. The setting tool  10  further includes a pin guide, the setting direction side, end piece  18  of which is shown in FIG.  1 . Before actuation of the setting tool, a bolt, nail or the like is advanced into the pin guide  18 . Upon actuation of the trip switch  16 , an explosive combustion of the fuel in the tool combustion chamber is initiated. The combustion of fuel leads to displacement of the drive piston that drives, e.g., the nail, which is located in the pin guide, into e.g., constructional component. Conventionally, bolts, nails, etc. . . . are arranged in a magazine, such as a magazine  42  shown in the drawings, and are advanced into the pin guide automatically. 
     The fuel for the setting process, in the embodiments of the setting tool shown in the drawings is fed from a fuel reservoir arranged outside of the tool housing. In the embodiment shown in FIG. 1, the fuel is fed from the reservoir  20  mounted on the housing  11 . The reservoir  20  has an elongate shape and extends along a longitudinal axis  22  which extends substantially parallel to the tool axis  12  of the setting tool  10 . The fuel reservoir  20  has a jacket  21  that surround the loading chamber. The jacket  21  has a bottom  29  and an end surface  30  in which a fuel outlet is provided. Also provided on the end surface  30 , a receptacle  31  and a connection member  27  that cooperates with a matching connection member  17  provided on the housing for releasably securing the fuel reservoir  20  on the housing  11 . The connection members  17 ,  27  also provided, in the embodiment shown in FIG. 1, for connection between the fuel reservoir  20  and a tool-side, fuel conduit leading to the tool combustion chamber. In order to prevent the fuel reservoir from inadvertently falling off the setting tool during the operation of the setting tool  10 , securing means  19  is provided, e.g., in the region of the bottom  29 . The securing means  19  is secured at one of its end to the housing  11  and with its other end engages the fuel reservoir  20  from behind, preventing disconnection of the connection members  17  and  27 . The jacket  21  of the fuel reservoir  20  has a concave surface section  23  that forms a contact surface  28  abutting the outer surface section  13  of the housing  11  of the setting tool  10 . The jacket  21  further has three convex surface sections  24 . The shape of the reservoir  20 , which is defined by the concave surface section  23  and the free convex surfaces  24  insures a reliable support of the reservoir  20  on the tool housing  10 . 
     FIG. 6 shows, as it has already been discussed, the cross-section of the fuel reservoir  20  according to the resent invention. As shown in FIG. 6, the geometry of the cross-section of the fuel reservoir  20  transverse to its axis  22  is defined by two envelope circles  211 ,  212 , with the inscribed envelope circle  211  being substantially smaller, more than in two times, than the circumscribing envelope circle  212  that surrounds the largest longitudinal extent of the jacket  21  of the fuel reservoir  20 . 
     FIG. 2 shows a second embodiment of a setting tool according to the present invention. In this embodiment, there is provided, on the setting tool  10 , a housing pocket  41  into which the fuel reservoir  20  is pushed. As in the embodiment of FIG. 1, the reservoir  20  is releasably secured to the housing  11  with the connection members  17 ,  27 . To facilitate the insertion and the removal of the reservoir  20 , there is provided, on the outer wall of the pocket  41 , at its rear end, at least one break-out  43  through which the reservoir  20  can be manually seized and retracted from the housing pocket  41  upon release of the connection members  17  and  27 . 
     In the embodiment of the inventive tool shown in FIG. 3, a fuel reservoir  20 ′ is located in al housing pocket  43 ′ provided between a central housing section  14  and the handle  15 . In this embodiment as in the embodiment of FIG. 1, the contact surface  28  of the reservoir  20 ′ is adapted to the outer surface  13  of the housing  11 . Despite the fuel reservoir  20 ′ being arranged between the central housing section  14  and the handle  15 , the setting tool  10  has a favorable center of gravity that insures an easy handling of the setting tool  10 . This is because the fuel reservoir  20 ′ is formed as a relatively flat body the geometry of which is characterized by the inscribed envelope which is substantially smaller than the circumscribing envelope (in cross-section perpendicular to the reservoir axis). As in the previous embodiments shown in FIGS. 1-2, the reservoir  20 ′ is mounted on the central housing section  14 , which provides a visual impression of proper proportionality. 
     FIG. 4 shows an arrangement of a fuel reservoir  20 ″ in a spandrel between the central housing section  14  and the handle  15  in a housing pocket  41 ″. The jacket  21 ″ of the reservoir  20 ″ has a linear surface section  25  and a concave  26  and convex  23 ,  24  surface sections which come together at a common edge  26 . In the embodiment shown in FIG. 4, the housing pocket  41 ″ forms an integral part of the housing  11 . 
     FIG. 5, which shows the cross-section of the fuel reservoir shown in FIG. 4, illustrates that the characterizing envelope circles  211 ,  212  are also so formed that the inscribed envelope  211  is substantially smaller than the circumscribing envelope circle. Also, the combination of concave, convex, and linear or even surface sections  23 ,  24 ,  25  insures an optimal adaptation of the fuel reservoir  20 ″ to the geometry or present dimensions of the tool housing  11  and the tool handle  15 . 
     Though the present invention was shown and described with references to the preferred embodiments, such are merely illustrative of the present invention and are 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 embodiments 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.