Patent Publication Number: US-8118196-B2

Title: Cartridge pistol with a cartridge holder

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. §365(a) to International Patent Application No. PCT/IB2005/000947, filed Apr. 6, 2005, and under 35 U.S.C. §120 to International Patent Application No. PCT/IB2005/000947, filed Apr. 6, 2005, which claims priority to Swiss Patent Application No. 00619/04, filed Apr. 8, 2004. 
     FIELD OF THE INVENTION 
     The invention generally relates to a cartridge gun with a cartridge holder. 
     BACKGROUND OF THE INVENTION 
     Cartridge guns, also known as cartridge presses, are known in the art, and may be used for pressing out pasty materials from cartridges, e.g. sealing materials, adhesive materials, and the like. In general, these cartridge presses comprise a shell for receiving a cartridge wherein the shape of the shell matches the external shape of the cartridge. One side of the shell is fastened to the handle of the cartridge press and comprises a recess in which a pressure rod with the stamp attached thereto is displaceable. The opposite side of the cartridge press is slotted, so that the tip of the cartridge which comprises a displaceable floor acting as a piston can be placed in said slot. The pressure rod, comprising an actuating member in the form of a swivelable trigger lever, can be pushed forward by a gun-like actuating or triggering mechanism. The pressure rod is moved a short step forward during each triggering movement. The actuating mechanism comprises an advancing element which is pushed forward by the manual movement of the actuating member and entrains the pressure rod. When the actuating member is released, the advancing element slides back onto the pressure rod. 
     A major disadvantage in the above-described cartridge presses is their overall size, resulting in added weight of the cartridge presses. The cartridge holder is generally made of sheet metal or the like, which results in a relatively high consumption of material. Approximately half the material required for such cartridge presses is used for the construction of the cartridge holder, which has an effect on the overall weight of the cartridge gun. A reduction of the share of material of the cartridge holder and a reduction in the weight is therefore desirable. A further disadvantage of these cartridge holders is that the insertion and removal of the cartridges is cumbersome because they frequently jam. 
     DE G89 01 028.0 discloses a hand press gun, in which a screw cap with an inside thread is attached to the face side of a gun grip, into which a threaded ring with an external thread and axial bore is screwed. The cartridge, comprising a flange at the rear end, is pushed from behind through the threaded ring until the flange abuts on the rear side of the threaded ring, and the threaded ring is screwed into the screw cap. 
     EP-A2-1 034 847 discloses a cartridge press with a cartridge holder comprising claws having free ends which engage in the outside wall of a cartridge pushed into the holder. The claws dig slightly into the material of the cartridge, so that the cartridge is held in a secure manner. A displaceable sleeve is pressed against the cartridge holder and against the claws for removing the cartridge from the cartridge holder, as a result, the cartridge can be pulled from the cartridge holder. 
     The above-mentioned hand press gun and cartridge press have the disadvantage in that the exchange of cartridges is cumbersome and time-consuming. A threaded ring or a sleeve needs to be unscrewed first or actuated before the cartridge can be removed from the cartridge holder. This manipulation is cumbersome because the process requires three actions: holding the gun, unscrewing the threaded ring and pressing the cartridge against the claws, and removing the empty cartridge from the cartridge gun. 
     SUMMARY OF THE INVENTION 
     A cartridge gun comprising a cartridge holder is provided. The inventive cartridge gun requires little material and allows a simple exchange of cartridges. The cartridge gun comprises a piston rod and a base in which the lower end of a cartridge is insertable. Gripping elements are arranged in the base which engage the inside wall of the inserted cartridge and hold the cartridge. To release the gripping elements, the piston rod is withdrawn completely from the cartridge until a stamp arranged at the front end of the piston rod presses back the gripping elements from the gripping position and releases the cartridge for removal. The advantage of such a cartridge gun is that the cartridge receiver, comprising a base, does not extend over the entire length of the cartridge to be inserted therein. Material is saved by omitting a shell construction for the cartridge holder. The overall weight of the cartridge gun can thus be kept low. The cartridge gun further comprises an actuating device for displacing the piston rod, which allows the displacement of the piston rod in a continuous manner, alternating in the forward direction or in the reverse direction. A stamp, comprising a rearward projecting stamp, is arranged at the front end of the piston rod. To remove a used or empty cartridge, the stamp is retracted with the piston rod until the edge of the stamp rests on the gripping elements arranged in the base of the cartridge holder. The retraction of the stamp can be achieved either by pulling at the rear end of the piston rod or by multiple pressing of a retraction lever, which displaces the piston rod in a rearward direction. By pressing the retraction lever, the stamp presses against the gripping elements and detaches the gripping elements from their anchoring in the cartridge wall. The cartridge can thus be removed without any obstructions from the cartridge holder. The removal of a used or empty cartridge from the inventive cartridge gun is thus substantially simplified, when compares to cartridges guns or presses known in the art. 
     A further advantage of the inventive cartridge gun is that the actuating device allows a displacement of the piston rod in a continuous manner in the forward and rearward direction. One problem with conventional cartridge guns or presses is that a pressure builds up within the cartridge during the advancement of the stamp, which is attached to the piston rod. After the emission of the pasty material within the cartridge, a subsequent dripping of the pasty material within the cartridge usually occurs due to the release of the pressure within the cartridge, thus achieving precise dosing and apportioning of the pasty material is difficult. The subsequent dripping of the pasty material can soil the ambient environment. The pressure build-up within the cartridge which causes the subsequent dripping is caused by the fact that the medium to be pressed out from the cartridge comprises a certain compressibility and also by a certain elastic deformability of the cartridge. Subsequent dripping can be avoided when the pressure within the cartridge is reduced. This reduction of pressure can be achieved by withdrawal of the stamp before the pressure begins to build up within the cartridge. Once sufficient pasty material has been released from the cartridge attached to the inventive cartridge gun, the retraction lever is pressed slightly, resulting in the stamp being slightly withdrawn, and the force from the stamp cease to act on the piston. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be described in greater detail in the following detailed description, with reference to the accompanying drawings, wherein: 
         FIG. 1  shows a side view of an embodiment of a cartridge gun; 
         FIG. 2  shows a cross-sectional side view of the cartridge gun shown in  FIG. 1 , with an inserted cartridge; 
         FIG. 3  shows a cross-sectional side view of the cartridge gun shown in  FIG. 2 , with an enlarged illustration of the cartridge holder and the actuating device for displacing the piston rod; and 
         FIG. 4  shows cross-sectional side view of the cartridge gun shown in  FIG. 2 , with an enlarged illustration of the cartridge holder, the actuating device for displacing the piston rod, and a completely retracted stamp. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A cartridge gun comprising a cartridge holder is provided. The inventive cartridge gun has the advantages of weighing lighter than cartridge guns or presses known in the art and being able to substantially eliminate the subsequent dripping of materials released from the cartridge due to the pressure build-up within the cartridge when the cartridge is pressed. 
       FIG. 1  shows a side view of an embodiment of a cartridge gun  1 . The cartridge gun  1  comprises a housing  7 , a grip  2 , and a cartridge holder  3 . The housing  7  comprises a piston rod  4 , and an advancement and retraction device for displacing the piston rod  4  is arranged in the housing  7 , and the device can be actuated by way of a pressure or advancement trigger  8 . The piston rod  4  is moved forward a short step towards the front of the cartridge gun  1  with each pressure movement on advancement trigger  8 , and it is moved a short step backward towards the rear of the cartridge gun  1  following a pressure movement of a retraction trigger  9 . The term “front” refers to the area where cartridge holder  3  is arranged on cartridge gun  1 , as shown in the accompanying figures, and the term “rear” refers to the opposite end of the “front” of cartridge gun  1 . The piston rod  4  comprises a stamp  5  at its front end and the rear end of the piston rod  4  is provided with a holding knob  6 . The holding knob  6  can be used to withdraw the piston rod  4  or it can be used to push into the cartridge up to the cartridge floor. 
       FIG. 2  shows a cross-sectional view of the cartridge gun  1  shown in  FIG. 1 , with a cartridge  10  inserted into the cartridge holder  3 . The cartridge  10  is shown without any content and without the cartridge floor which forms the piston. In the embodiment shown in  FIG. 2 , the piston rod  4  has been fully withdrawn. With each pressure movement on the advancement lever  8  in the direction towards the grip  2 , the piston rod  4  is pressed slightly forward into the cartridge  10  in the direction towards nozzle  11 . During this process, the stamp  5  presses against the piston in the cartridge (not shown) and presses the pasty material situated in the cartridge  10  outwardly through the nozzle  11 . A short pressure movement on the retraction lever  9  in the direction towards the grip  2  pushes the piston rod  4  a small step backwards towards the rear of the cartridge gun  1 , whereupon the piston in the cartridge  10  is relieved and the pressure in the cartridge  10  is reduced. Subsequent dripping of any pasty material within the cartridge  10  can thus be avoided. 
       FIG. 3  shows an enlarged cross-sectional view of  FIG. 2 , illustrating the cartridge holder  3  and an actuating device arranged in housing  7  for displacing the piston rod  4 . The cartridge holder  3  comprises a cylindrical base  12  with an annular groove  14 . The outside diameter of the annular groove  14  corresponds to the outside diameter of cartridge  10 , so that the cartridge  10  can be inserted effortlessly into the annular groove  14  of base  12 , and rests on the outside wall of annular groove  14 . An axially extending, graduated hole bore  15  in the center of base  12  is used for receiving a hub  16 . A plurality of gripping elements  17  are clamped between the edge  20  of the collar  18 , which is formed by the annular groove  14 , hole bore  15 , and hub  16 . Said gripping elements  17  can be individual claws projecting into the annular groove  14 , wherein free ends of gripping elements  17  reach up to the outside wall of annular groove  14 . In the illustrated embodiment as shown in  FIG. 3 , the gripping elements  17  are formed by the jacket surface with longitudinal slots of an element in the shape of a truncated cone. The upper cover surface of the truncated element comprises a bore in such a way that the remaining circular ring of said cover surface can be clamped between hub  16  and the edge  20  of the collar  18 . Strip-like gripping elements  17  are obtained by the slots in the jacket surface of the truncated element, wherein the free ends project into the annular groove  14  in the direction towards the housing  7  of the cartridge gun  1  up to the outside wall of the annular groove  14  and can be provided with a sharp edged or pointed configuration. In order to ensure sufficient stability and elasticity of the resilient gripping elements  17 , gripping elements  17  are made of, but not limited to, spring steel and the like. Once a cartridge  10  is pressed into the base  12  of the cartridge holder  3 , the gripping elements  17  press with their free ends against the inside wall  13  of the cartridge  10 , wherein the cartridge  10  is securely held. As soon as stamp  5  is used to press against the piston in the cartridge  10 , a pressure is also exerted on the cartridge  10 , resulting in a pressing action of the cartridge  10  from the cartridge holder  3 . This pressing action is prevented because the gripping elements  17  tightly grasp the side wall of the cartridge  10 . 
     As shown in  FIG. 3 , a forward drive disk  21 , which is tiltable, is attached to the housing  7 , with the piston rod  4  projecting through its opening. The opening on the forward drive disk  21  is slightly larger than the diameter of the piston rod  4 , so that the forward drive disk  21  is freely displaceable along the piston rod  4 . The forward feed disk  21  is pressed to the back by the pressure spring  22 . The grip  2  comprises an advancement trigger  8  which acts upon the lower side of the forward drive disk  21 . As a result of actuating the advancement trigger  8 , the forward drive disk  21  is tilted forwardly until it presses against the piston rod  4  and gets jammed, and it is further pressed forward against the pretension force of the pressure spring  22 . It forwardly moves the piston rod  4  with the stamp  5 . A further tiltable drive disk  24  for the rearward displacement of the piston rod  4  is attached to the housing  7 . This retraction drive disk  24  is pressed forwardly by the pressure spring  22 . A retraction trigger  9  which can be swiveled about an axis  19  is arranged in the housing  7  for the reverse displacement of the piston rod  4 , which acts upon the lower side of the retraction drive disk  24 . The retraction drive disk  24  is tilted in a rearward manner by actuating the retraction trigger  9  until it presses against the piston rod  4  and gets jammed, whereupon it is pushed further back against the pretension force of the pressure spring  22 , whereby the piston rod  4  with the stamp  5  moves towards the rear of the cartridge gun  11 . 
     In FIG.  3 ., the piston rod  4  and the cartridge  10  are shown in retracted positions. By pressing the advancement trigger  8 , the piston rod  4  with the stamp  5  is pressed continuously in the forward direction into the cartridge  10  and against the piston of cartridge  10 , whereby the material within the cartridge  10  are pressed and ejected from the cartridge  10 . Once sufficient material has been ejected from cartridge  10 , applying slight pressure or pulling on the retraction trigger  9  towards the rear of cartridge gun  1  is sufficient move the piston rod  4  slightly backwards or towards the rear of cartridge gun  1 . As a result of pulling the retraction trigger  9 , the pressure acting on the piston within the cartridge  10  by stamp  5  is substantially eliminated, and the excess pressure in cartridge  10  is reduced, thus preventing subsequent dripping of the material within the cartridge  10 . The stamp  5  which is arranged at the front end of the piston rod  4  comprises a plane front surface and a rearwardly projecting edge  25  which is slightly sloped at its end  26 . The sloping corresponds approximately to the inclination of the gripping elements  17 . To remove or exchange an empty or used cartridge  10 , the piston rod  4  is pushed towards the rear of the cartridge gun  1 . This action can be achieved manually by pulling the piston rod  4  to the back on the knob  6  until the stamp  5  rests with its edge  26  on the gripping elements  17 . The retraction of the piston rod  4  can also be achieved by actuating the retraction trigger  9  several times until the stamp  5  is fully retracted. To remove the cartridge  10  from the cartridge holder  3 , the cartridge  10  is held by one hand of the user, while actuating the retraction trigger  9  by the other hand. This action causes the sloping end  26  of the edge  26  of stamp  5  to press against the resilient gripping elements  17 , which are pressed away from the inside wall  13  of the cartridge  10 , and the cartridge  10  can be removed from the cartridge holder  3 . As soon as the stamp  5  has been pushed in a forward direction towards the front of the cartridge gun  1  again, the resilient gripping elements  17  return to their initial position as a result of their elasticity, which means that the free ends of the gripping elements  17  reach up to the inner edge of the circular groove  14  again. 
       FIG. 4  shows an enlarged cross-sectional view of the housing  7  with the cartridge holder  3  and the actuating device for displacing the piston rod  4  when the stamp  5  is fully retracted.  FIG. 4  further shows the retraction trigger  9  in a pressed position and the gripping elements  17  are pressed from the rearward projecting edge  25  of the stamp  5  against the inside, thus releasing the boundary region of the annular groove  14 , as a result, the cartridge  10  can be withdrawn from the cartridge holder  3 . 
     The embodiments shown in  FIGS. 1-4  illustrate cartridge gun  1  in which the housing  7 , the grip  2 , and the cartridge holder  3  is of an integral configuration and may be, made of plastic, for example. In another embodiment, cartridge gun  1  includes individual parts and the base  12  of the cartridge holder  3  is screwed onto the face side of the housing  7 . 
     While certain embodiments of the present invention have been described, it will be understood that various changes may be made in the above invention without departing from the scope of the invention. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     REFERENCE NUMERALS 
     
         
           1  Cartridge gun 
           2  Grip 
           3  Cartridge holder 
           4  Piston rod 
           5  Stamp 
           6  Knob at the end of the piston rod 
           7  Housing of the cartridge gun 
           8  Advancement trigger 
           9  Retraction trigger 
           10  Cartridge 
           11  Nozzle 
           12  Cylindrical base 
           13  Inside wall of cartridge 
           14  Annular groove 
           15  Graduated hole bore 
           16  Hub 
           17  Gripping element (gripper) 
           18  Collar adjacent to hub 
           19  Axis lever  9   
           20  Edge of collar adjacent to hub 
           21  Forward drive disk 
           22  Pressure spring 
           23  Axis lever  8   
           24  Retraction drive disk 
           25  Collar on stamp 
           26  Incline of collar  25