Abstract:
A propellant charge-operating setting tool for driving fastening elements and including a housing ( 11 ), a setting mechanism ( 12 ) located in the housing ( 11 ) and actuated in response to ignition of a propellant charge ( 24 ) for driving in a fastening element, and a device ( 30, 40, 50, 60, 70 ) for cutting a used portion of a propellant charge-carrying magazine strip ( 22 ).

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a propellant charge-operated setting tool for driving in fastening elements, such as nails, bolts, pins, etc. . . in a constructional component and including a housing, and a setting mechanism located in the housing and actuated in response to ignition of a propellant charge, which is carried by magazine strip displaceable in the setting tool, for driving in a fastening element.  
           [0003]    2. Description of the Prior Art  
           [0004]    The propellant charge, which is used in the setting tools of the type described above, is formed as a pill or cartridge of a powder fuel. A plurality of such pills or cartridges is arranged on a magazine strip. Magazine strips are pushed through a feeder provided on a setting tool, with a single charge being received at a time in a cartridge socker. The magazine strip with blisters of pills or cartridges is automatically displaced through the setting tool upon completion of a setting process for placing a new charge in the cartridge socket.  
           [0005]    A setting tool of the type described above is disclosed in German Publication DE 199 01 268 A1.  
           [0006]    In order to be able to conduct a greatest possible number of setting processes without the replacement of the necessary cartridges, blisters, or magazine strips, there was proposed to use very long magazine strips.  
           [0007]    U.S. Pat. No. 4,204,473 discloses a cartridge strip with a large number of propellant charges The cartridge strips are arranged in a magazine box. The cartridge or magazine strips in this magazine box are arranged in layers.  
           [0008]    U.S. Pat. No. 6,053,108 discloses an arrangement of pill-shaped charges in a blister or magazine strip, and an arrangement of powder charges in a cartridge strip. The magazine or cartridge strip contains a large number of charges and is unwound along a spiral.  
           [0009]    The drawback of the use of such long magazine strips, such as cartridge of blister strips, in setting tools consists in that they make handling of the setting tools very difficult when a large section of the used portion of the magazine strip extends from or is suspended from a setting tool.  
           [0010]    Accordingly, an object of the present invention is to provide a setting tool of the type described above in which the drawback of the prior art is eliminated and in which a long magazine strip can be used without adversely affecting handling of the setting tool.  
         SUMMARY OF THE INVENTION  
         [0011]    This and other objects of the present inventions which will become apparent hereinafter, are achieved by providing the setting tool with a device for cutting the magazine strip.  
           [0012]    The cutting device permits to separate an empty section, of the magazine strip, e.g., of a cartridge or blister strip from a usable section of the magazine strip. The cutting device in this way prevents formation of long empty ends of magazine strip suspendable from the setting tool and which made the handling of the tool more difficult. The cutting devices can be, e.g., of a mechanical type or also include electrical components for control purposes and for an automatic start of a cutting process. The use of a cutting device simultaneously permits to eliminate, in the setting tool, a storage space for the used section of the magazine strip, which otherwise would have been needed and which occupies a large space in the setting tool.  
           [0013]    Advantageously, the cutting device has at least one cutting element arranged behind the cartridge socket in the displacement direction of the magazine strip, so that it always cuts the used portion of the magazine strip. Ideally, the cutting element is so arranged that it effects transportation of the magazine strip during the cutting process while severing the magazine strip.  
           [0014]    To prevent suspension from the setting tool of non-yet used magazine strip, specific magazine-receiving means is provided in the setting tool in which the magazine strip can be placed.  
           [0015]    According to one advantageous embodiment of the present invention, the magazine-receiving means is formed as a magazine comportment displaceable between a first position corresponding to an operational position of the setting tool, and a second position corresponding to a position of the setting tool in which insertion/removal of the magazine strip is possible.  
           [0016]    An arrangement of a magazine strip in a magazine or magazine box from which the strip can be pulled out, advantageously insures a reliable support and transportation of magazine strips. Further, an easy handling of the setting tool is also insured.  
           [0017]    Advantageously, the cutting element can be mounted on the magazine compartment and be fixedly connected therewith. When the magazine compartment is displaced from the operational position to a removal position, the cutting element is displaced through the displacement path of the magazine strip, cutting off the used portion of the magazine strip, so that the used portion falls out of the setting tool. The magazine compartment functions similar to a drawer which is used for inserting the magazine box into the setting tool and for removal the magazine box from the setting tool. The movement of the magazine compartment is similar to that of a magazine of an automatic gun. By the time the magazine box is removed from the tool, the cartridge or magazine strip is cut out. It is advantageous when the used portion of the magazine strip can be easily removed only with a partial movement of magazine strip. In this case the magazine strip is cut out by a blade provided on the magazine compartment.  
           [0018]    According to a further advantageous embodiment of the present invention, the setting tool has two housing parts movable relative to each other. The two parts can move relative to each other as a result of recoil of the setting tool upon ignition of the propellant charge. According to the invention, the cutting element, e.g., a blade is so arranged on one of the housing parts that it is displaced through the displacement path of the magazine strip in response to movement of the two parts relative to each other which is caused by the recoil of the tool.  
           [0019]    A particular advantage of cutting of the used portion of the strip as a result of the recoil of the tool consists in that a user of the setting tool does not need initiate a cutting process after a setting step as the magazine strip is already cut automatically, with the cut-out blisters and/or cartridges falling out.  
           [0020]    The adverse effect of recoils on the tool user, and cutting off the magazine strip upon pressing of the tool against an object is prevented by arranging a damping device that can be formed, e.g., of a damping element and a spring element, between the two housing parts for preventing a relative movement therebetween. When one of the housing parts includes a handle, with the use of the dampening device, no additional damping means is needed in the interior of the tool, which simplifies the construction of the setting tool.  
           [0021]    Further with the described embodiment, the entire recoiling mass of the tool is used for effecting the cut, which permits to make the tool relatively light.  
           [0022]    According to another advantageous embodiment of the present invention, the cutting device comprises a manually actuated actuation lever and a pivotal cutting element that upon actuation of the actuation lever, is displaced through the displacement path of the magazine strip for cutting the used portion of the magazine strip. The actuation lever and the cutting element are brought back into their initial position by an appropriate spring element. With this embodiment, a tool user can effect cutting-off of the used section only then when the suspended portion interferes with the handling of the setting tool.  
           [0023]    Advantageously, the actuation lever and the pivotal cutting element are formed as a one-piece part supported on a single pivot axle. The cutting device of this type can be easily manufactured and is relatively inexpensive.  
           [0024]    Besides this simple mechanical cutting device, other manually actuated cutting devices without a pivotal lever can be used. E.g., mechanical cutting devices with which the cutting element, e.g., a blade, performs a translational movement through the displacement path of the magazine strip.  
           [0025]    According to a further advantageous embodiment of the present invention, the cutting device or at least the cutting element are electronically controlled. The advantage of an electronically controlled cutting element or a complete electronic cutting device consists in that the cutting process can be effected without any physical intervention of a tool user, with the cutting process being controlled in accordance with predetermined criteria. E.g., the following logical condition can lead to the initiation of a cutting process. E.g., the cutting process can be initiated after, e.g., at least an X number of cartridges have been used or fired, after a setting process ends, or upon actuation of a trigger or an actuation button. Such control eliminates excessive cuttings.  
           [0026]    According to a further advantageous embodiment of the present invention, an electronic cutting device or an electronically controlled cutting element has an electrical drive, e.g., an electric motor or a solenoid. The electrical drive can be associated with a gear set. Thus, when the electrical drive has a small power capacity and a high-speed motor, a gear set with a high transmission ratio can drive a rotatable cutting element. The control of the electric motor and the transmission ratio can be so selected that a rotatable knife would perform exactly one revolution per cut.  
           [0027]    It is advantageous when the cutting element is formed as an eccentrically rotatable cutting body, e.g., as a spiral knife or a spiral blade. Preferably, the rotatable cutting body or the spiral knife has a recess that would permit passing of propellant charges or blister cartridges during displacement of the magazine strip. With this embodiment of a cutting device, complicated movements of the cutting element can be avoided and which otherwise would have to be effected by an appropriate control of the electrical drive.  
           [0028]    According to yet another advantageous embodiment of the present invention, the electronically controlled cutting element is formed as a thermal cutting element, e.g., as an incandescent wire or a heatable blade. With such a cutting element, e.g., the incandescent wire, the magazine strip can be melt through at a desired point in time. Advantageously, the thermal cutting element is spring-biased toward the magazine strip. It is further advantageous when a feeler or scanning element, which cooperates with the thermal cutting element, is provided. The feeler element can scan cutting marks provided on the magazine strip. The thermal cutting element or the incandescent wire usually slides over the magazine strip, without being hot, or is spaced by a small distance from the magazine strip. The scanning element or the feeler is usually made of an electrically insulating material and also slides over the magazine strip, which is made of a plastic material, under an action of a biasing force. When a cutting mark which, e.g., coincides with transportation holes provided on the magazine strip, is scanned, the feeler falls into a hole(s), causing lowering of the cutting element. If the cutting element is not under current, i.e., that wire does not glow, the wire would prevent further falling of the feeler into the transportation hole. The magazine strip can be further advanced into a longitudinal direction If a cut should be made, and the wire is hot, the magazine strip would be molten through.  
           [0029]    According to a yet another advantageous embodiment of the present invention, the cutting element is formed of two, inclined to each other cutters forming together an angle which is not equal 180°. With such configuration of the cutter arrangement, with the cutters being inclined toward each other or away from each other, the cutting process can be effected with a smaller expenditure of force that with a cutter(s) not inclined to the magazine strip.  
           [0030]    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  
       [0031]    The drawings show:  
         [0032]    [0032]FIG. 1. A schematic, partially cross-sectional side view of a first embodiment of a setting tool according to the present invention in an operational position thereof with a magazine of to-be-set fastening elements located in the setting tool;  
         [0033]    [0033]FIG. 2. A schematic, partially cross-sectional, side view of the setting tool shown in FIG. 1 in its transitional position between the operating position and a position in which the magazine with to-be-set fastening elements is removed;  
         [0034]    [0034]FIG. 3. A schematic, partially cross-sectional, side view of the setting tool shown in FIG. 1 in the position in which the magazine with to-be-set fastening elements has been removed;  
         [0035]    [0035]FIG. 4. A schematic, partially cross-sectional side view of a second embodiment of a setting tool according to the present invention in an operational position thereof with a magazine of to-be-set fastening elements located in the setting tool;  
         [0036]    [0036]FIG. 5. A schematic, partially cross-sectional side view of a third embodiment of a setting tool according to the present invention in an operational position thereof with magazine of to-be-set fastening elements located in the setting tool;  
         [0037]    [0037]FIG. 6. A schematic, partially cross-sectional, side view of the setting tool shown in FIG. 5 after actuation of the cutting device for a magazine strip;  
         [0038]    [0038]FIG. 7. A schematic cross-sectional view of cutting means according to the present invention and of a magazine strip;  
         [0039]    [0039]FIG. 8. A schematic cross-sectional view of another embodiment of cutting means according to the present invention and of a magazine strip;  
         [0040]    [0040]FIG. 9. A schematic view of the cutting device according to the present invention;  
         [0041]    [0041]FIG. 10. A schematic, partially cross-sectional, side view of a setting tool according to the present invention with the cutting device shown in FIG. 9 and located in the setting tool;  
         [0042]    [0042]FIG. 11. A perspective view of a further embodiment of a cutting device according to the present invention; and  
         [0043]    [0043]FIG. 12. A cross-sectional view of the cutting device shown in FIG. 11. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0044]    A setting tool according to a first embodiment, which is shown in FIGS.  1 - 3 , has a housing  11  and a setting mechanism  12  located in the housing  11 . The setting mechanism  12  includes a drive piston  12  located in a piston guide  13  or in a piston chamber, and a cartridge chamber or a cartridge socket  14  in which a cartridge or a propellant charge  24  is received. Upon ignition of the located in the cartridge socket  14 , propellant charge  24 , the drive piston  12  would be driven away from the cartridge socket  14  by explosive gases and would be able to perform a setting operation, e.g., to drive a nail or a bolt, which is located in a bolt guide  13 , into a constructional component. The inventive setting tool, which is shown in the drawings, further includes a handle  17 , on which a trigger  18  or other type of an actuator is provided. Upon being actuated, the trigger  18  initiates the ignition of the propellant charge  24  located in the cartridge socket  14 . The setting tool further includes a magazine compartment  21  having magazine-receiving means  20  in which a magazine box  27  is received.  
         [0045]    The setting tool is shown in FIG. 1 in its operational position  25  in which actuation of the setting tool is possible. In the position  25 , the magazine box  27  cannot be removed from the setting tool because it is secured in the magazine compartment  21  with a locking element  29 . In addition to the locking element  29 , other locking or fastening means can be provided which can be arranged in the setting tool independently of the magazine compartment  21 . The magazine box  27  contains a magazine strip  22  that can be pulled out from the magazine box  27 . The propellant charges  24  are arranged on the magazine strip  22 . The magazine strip  22  can be formed, e.g., as a blister strip on which pill-shaped propellant charges  24  are arranged. The magazine strip can also be formed as a cartridge strip with cartridges with a powder charge being arranged on the cartridge strip.  
         [0046]    In the operational position of the setting tool, not yet ignited propellant charge  24  is located in the cartridge socket  14 , with the propellant charge  24  being sealingly supported against the bottom  14 ′ of the cartridge socket  14  when the setting tool is pressed against a constructional component.  
         [0047]    The magazine compartment  21  forms part of a cutting device which, in addition to the magazine compartment, includes a blade or cutter  31  fixedly connected with the magazine compartment  21 . The magazine compartment  21  is displaceably arranged in the setting tool.  
         [0048]    In FIG. 2, it is shown that the magazine compartment  21  is displaced in a direction shown with an arrow so that the cutter or blade  31  can be displaced across of a displacement path  23  of the magazine strip  22 ′ for cutting the magazine strip  22 ′. The separated end of the magazine strip  21  can be removed from the setting tool or it falls out. In this transitional or intermediate position of the setting tool, the locking element  29  is already released. However, as discussed above, there can be provided other locking or retaining means that could retain the magazine box  27  in the setting tool.  
         [0049]    In the position shown in FIG. 3, the magazine compartment  21  is pulled all the way backward to its second position  26  so that the magazine box  27  can be removed from the magazine compartment  21 . The cartridge bottom  14 ′ is so far removed from the cartridge socket  14  that the propellant charge  24  still located in the cartridge socket  14  can be withdrawn from the socket  14 , and the magazine strip  22  can be pulled in a direction of arrow  32  from the setting tool.  
         [0050]    It should be pointed out that the user can cut the magazine strip  22  in a simple manner, without withdrawing the magazine box  27 , by displacing, for a short time, the magazine compartment  21  into the position shown in FIG. 2 and then displacing it back into the position.  
         [0051]    [0051]FIG. 4, as discussed above, shows another embodiment of a setting tool according to the present invention. In the embodiment shown in FIG. 4, the setting mechanism  12  includes, in addition to the elements discussed with reference to FIGS.  1 - 3 , a magazine  90  for fastening elements, such as nails, bolts, etc. . . , which is attached to the bolt guide  13 ′.  
         [0052]    In the setting tool shown in FIG. 4, the magazine receiving means  20  is located directly in housing  11  of the setting tool. The setting tool has two housing parts  15  and  16 . The setting mechanism  12  is located in the housing part  15 , and the housing part  16  includes the handle  17  with the trigger  19 . A damping device  42 , which is formed, in the embodiment of the setting tool shown in FIG. 4 of a spring  43  and a damping element  44 , is arranged between the two housing parts  15  and  16 . The object of the damping device  42  is to damp the recoils of the setting tool upon explosion of the propellant charge  24  in the cartridge socket  14 . Another object of the damping device  42  is to insure a positional stability of the housing part  15  and  16  relative to each other when the setting tool is pressed against a constructional component. The magazine strip  22  is guided in the setting tool of FIG. 4. through a free space or gap between the housing parts  15 ,  16  and outside of the setting tool. A cutting device  40  is provided in the region of the free space between the housing parts  15  and  16 . In the embodiment shown in FIG. 4, the cutting member  41  provided on the first housing part  15 , and a cutting member  45  is provided on the second housing part  16  and located approximately opposite the cutting member  41 . Upon movement of the housing part  15  and  16 , upon explosion of the propellant charge  24  in the cartridge socket  14 , toward each other in direction of arrow  38 , the cutting member  41  is displaced toward the magazine strip  22  pushing it toward the second cutting member  45 , so that upon further movement of the housing parts  15  and  16  toward each other, a portion of the magazine strip  22 , which is suspended from the setting tool, is cut out.  
         [0053]    [0053]FIGS. 5 and 6 show a further embodiment of a setting tool according to the present invention. In this embodiment likewise, the magazine box  27  is located in the magazine-receiving means  20  of the housing  11 . The housing  11  is formed as a one-price part, and the setting tool is provided with a magazine  90  of to-be-set fastening elements. Above the housing  11 , there are provided a pivot lever  50  formed of an actuation/cutting lever  52  and a pivoted blade-shaped cutting member  51 . The pivot lever  50  is pivotally supported on a bearing  53 . In FIG. 5, the actuation/cutting lever  52  and the cutting member  51  and shown in their non-operational positions. The magazine strip  22  is displaced beneath the cutting member  51  which is arranged, in the displacement direction  23  of the magazine strip  22 , behind the cartridge socket  14 , as was the case in the embodiment of FIG. 4. It should be noted that the cutting member can be located in front of the cartridge socket (in the displacement direction of a strip). The position of a cutting member depends on a displacement mode of the magazine strip. When the displacement of the magazine strip is effected when the setting tool is pressed against a constructional component, the cutting mechanism can be arranged in front of the cartridge socket in the displacement direction.  
         [0054]    In the embodiment shown in FIG. 5, a second blade-shaped cutting member  55  is provided on the other side of the magazine strip  22  and serves as an end support for the cutting member  51 . Upon actuation of the pivot lever  50  in a direction of arrow  54  (which corresponds to the cutting movement), the blade-shape cutting member  51  pivots into the displacement path of the magazine strip  22 , as shown in FIG. 6. Thus, upon actuation of the lever  52 , the end  22 ′ of the magazine strip  22 , which extends beyond the setting tool, is cut out from the magazine strip  22 .  
         [0055]    The actuation/cutting lever  52  can be actuated by the setting tool user when necessary, e.g., when a lengthy piece of the magazine strip extends from the setting tool.  
         [0056]    [0056]FIGS. 7 and 8 show two other embodiments of cutting means according to the present invention. In the embodiment of FIG. 7, the cutting means has two cutters  81  arranged at an angle  82  to each other, with the angle  82  being less than 180° and forming a V-shaped profile. With this arrangement of cutters  81  relative to each other, the cutting strip  22  can be cut, in the direction of arrow  83 , with small expenditure of force.  
         [0057]    In the embodiment of FIG. 8, the two cutters  81  are arranged at an angle  82  to each other which is greater than 180°. Both cutter  81  are displaced to a common central point in which they can be displaced into an opening  85  in the magazine strip  22 . In this embodiment likewise, due to the inclination of the cutters  81  to the magazine strip  22 , the cut is effected in the direction of the arrow  83  without a great expenditure of force. Though cutting means with two cutters were described, the use of a single cutter within an angle of 180° is not, however, excluded.  
         [0058]    [0058]FIG. 9 shows another embodiment of cutting device  60  according to the present invention. The cutting device  60  has an electrical drive  63  and a gear set  64  connected with the electrical drive  63  and having an output shaft  65 . A rotating blade  61  is arranged on the free end of the shaft  65 . The blade  61  had on its circumference a cutter  69  that cuts the magazine strip  22  upon rotation of the blade in the direction of arrow  67 . To prevent deflection of the magazine strip  22 , a counter support  68 , e.g., a second blade, can be provided. The counter support  68  is arranged opposite the rotating blade  61  on the other side of the magazine strip  22 . For a free displacement of propellant charges  24  in a rest position of the rotating blade  61 , there is provided a recess  66  in the region of the cutter  69 .  
         [0059]    As shown in FIG. 10, the cutting device  60  is located within the setting tool which corresponds essentially to the setting tool shown in FIGS.  1 - 3 . The magazine box  27  is located in the magazine compartment  21 . The cutting device  60  is fixedly connected with the housing  11 . Upon withdrawal of the magazine compartment  21  in its withdrawal position, which the magazine box  27  is removed, the cutting of the magazine strip  22  is effected with the rotating blade  61  of the cutting device  60  upon electrical actuation of the drive  63 . The control circuit not shown in the drawing, however, the cutting process can be initiated by actuation of an electrical switch  62  provided on the handle  17 . However, the electrical control can be activated automatically, e.g., after each setting process or after a predetermined number of setting processes, for actuation of the cutting device  60 .  
         [0060]    FIGS.  11 - 12  show another embodiment of an electrical cutting device. The electrical cutting device  70 , which is shown in FIGS.  11 - 12 , includes a thermal cutting element, e.g., an incandescent wire  71 . The cutting device  70  is usually pivotally supported in a setting tool, not shown in FIGS.  11 - 12 , with bearing journals  75 . The cutting device  70  includes, in addition to the thermal cutting element, wire  71 , a feeler element  72  that is arranged beneath the thermal cutting element, wire  71 , at a small distance therefrom. The feeler element  72  is biased by a spring  73  that biases the feeler element  72  in a direction toward a magazine strip  22 . Holding elements  76  for the cutting element are fixedly connected, at least regionwise, with the feeler element  72 , whereby the thermal cutting wire  71  is also biased in the direction toward the magazine strip  22 . The feeler element  72  can be displaced toward, e.g., a cutting mark  74  on the magazine strip  22 . A cutting instruction can be communicated to the cutting element, wire  71 , by an electronic control system not shown. To this end, on the bearing journals  75 , electrical contacts  77  are provided through which current can be fed to the wire  71  to bring it to glow. The magazine strip  22  can be cut as a result of heating with the wire  71 .  
         [0061]    The cutting can be generally affected in accordance with a predetermined program or be initiated by actuation of an electrical switch provided on the setting tool handle or in another region of the setting tool, upon removal of the wire strip or the magazine box from the setting tool.  
         [0062]    Though the present invention was shown and described with the references to the preferred embodiments, such are merely illustrative of the present invention and are not to be construed as 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 with the spirit and scope of the present invention as defined by the appended claims.