Patent Publication Number: US-8528243-B1

Title: Pistols and methods of manufacture

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a co-pending application which claims priority to Austrian Application No. A520/2012, filed Apr. 30, 2012, which is incorporated by reference herein in its entirety. 
     TECHNICAL FIELD 
     The invention relates to a small caliber pistol, a pistol for low-impulse ammunition (e.g. 0.22 LR or 0.380 auto/9 mm short) or a training pistol. 
     DESCRIPTION OF THE RELATED ART 
     In general and specifically with respect to the application at hand, a training pistol or small caliber pistol or a pistol for low-impulse ammunition refers to pistols which resemble traditional pistols as closely as possible in terms of appearance, exterior dimensions and handling, but which are only suitable for use with low-impulse ammunition or training ammunition (blank cartridges, color marking cartridges, rubber bullets) because of altered breech components, barrels, magazines, etc. The reason for these efforts is the increased safety associated with training ammunition and the lower costs for low-impulse ammunition. 
     These types of designs are not only known for pistols; in fact, the Austrian Federal Armed Forces used a similar device for the Belgian-produced STG-58, said Belgian original being referred to as FN FAL. This weapon was available with the so-called K-device and after putting (screwing) it on, it was possible to fire blank cartridges, because with the virtually complete coverage of the mouth of the barrel even blank cartridges containing only a minimum amount of gun powder generated a sufficient amount of pressure to enable the automatic charge. In connection with this approach, it was and is extremely problematic that the K-device is optically inconspicuous, thus inevitably resulting in the destruction of the weapon and injury of the shooter when traditional ammunition is fired through the screwed-on K-device. 
     The barrel and slide of the aforementioned pistols are made of aluminum, while the regular material, usually steel, is left in place for the traditional handle parts. As a result of the mass reduction induced by the moveable parts, it is also possible for the propellants to sufficiently move the slide even when using low-impulse training ammunition, for example 9 mm FX in a weapon normally used with 9 mm ammunition, in order to push out the cartridge shell and pull the next cartridge into the breech. 
     From a technical point of view, the major issue is that the used moveable parts made of aluminum display a completely different thermal expansion behavior than the handle part of the weapon and the slide parts normally made of steel, resulting in problems especially in connection with longer exercises during which a greater number of shots are fired. Finally, the entire tribological behavior of aluminum in contact with the steel of the guides in the handle piece is extremely problematic and unforeseeable and results in a host of troubles. 
     The purpose and objective of the invention is to solve these problems and to create an exercise weapon in which as few parts as possible are different from those of the original weapon, in which the handling and the feel associated with the use of the weapon in training mode resemble the use of the original weapon as closely as possible in case of an emergency, in which the safety aspects are ensured the best they can possibly be, and which is in line with the prior art from an economical point of view. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is explained in more detail below based on the drawing. In the figure(s): 
         FIG. 1  shows a breech according to the invention including the barrel in the section I-I of  FIG. 3 , 
         FIGS. 2 to 4  show side views and a top view of the breech, 
         FIG. 5  shows the detail V of  FIG. 1 , 
         FIG. 6  shows the detail VI of  FIG. 1 , 
         FIG. 7  shows the section VII-VII of  FIG. 2 , 
         FIG. 8  shows the detail VIII of  FIG. 4 , 
         FIG. 9  shows the detail IX of  FIG. 7 , 
         FIG. 10  shows a cross section of the barrel part, 
         FIG. 11  shows an exploded sketch in perspective and 
         FIG. 12  shows a perspective representation of an entire weapon. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     The or a part of the slide that forms the barrel sheath and/or the or a part of the slide that forms the outer cover of the firing mechanism is not made of metal but of plastic, while the remaining part that carries or forms the guides and is in contact with the handle part includes regular steel in these types of pistols. The manufacture can either be realized by inserting the remaining residual metal slide in the fashion of a lost core into a matching mold of an injection molding machine or by customized injection molding of the plastic cover parts with correspondingly designed slot-spring connector elements both on the residual slide as well as the plastic parts. Adhesive joints are also an option. 
     In one embodiment, it is intended to design the barrel in a suitable shape for low-impulse ammunition and to fill the free volume remaining between the training barrel and the regular barrel with plastic, preferably by way of extrusion-coating the training barrel with an injection molding machine. In the process, the barrel is preferably arranged off-center or diagonal to the regular barrel axis, such that the trajectory of the low-impulse projectile coincides to the greatest possible extent with an imaginary trajectory of the projectile of the original weapon within the intended distance. 
     On the one hand, the measures achieve an excellent mass reduction of the moveable parts of the weapon, ensuring its full functionality in connection with the use of low-impulse ammunition while, on the other hand, any problems associated with the kinetic friction between steel and aluminum are prevented and finally, the plastic, preferably featuring a suitable color, achieves a highly visible optical cue to the effect that this concerns, e.g., a training weapon which may only be used with training ammunition or a low-impulse weapon with a caliber of e.g. 0.22 LR or 0.380 auto/9 mm short. In so doing, it is possible to use different colors to indicate different types of permitted ammunition. 
       FIG. 1  illustrates a cross section of the slide or breech  1  designed which corresponds to the plane through section I-I in  FIG. 3 , hence along the plane of symmetry in the barrel area and parallel to the plane of symmetry in the firing pin area. The barrel part  2  in locked position is also illustrated. The slide  1  comprises a steel frame  3  which is brought into an exterior shape illustrated in  FIG. 2  by means of a plastic part  4  provided in the area of the barrel cover and a plastic slide cover  5  in the area of the firing mechanism, and said shape is not deviating from a traditional pistol with respect to its outline. 
     As seen in  FIGS. 1 to 4 , the slide  3  or the residual metal slide  3  is reduced to two longitudinal bars  13 ,  14 , said bars extending along the entire length on the left and right side, just underneath the barrel in the direction of the barrel axis and they are essentially connected with the arc-shaped connector elements in three positions: in the area of the barrel opening and an outlet arc  15 , which also extends to below the guide plane of the slide  1  where it forms the abutment for the recuperating spring; behind the breech in a breech arc  16  and at the end of the breech  1  in a terminal arc  17 . In addition, the guide for the striking pin and the firing spring is designed in the region of the firing mechanism, nearly in the middle behind the barrel; this part  18  also connects the two longitudinal bars. 
     The figures and description illustrate that essential parts of the slide are made of plastic and that the respective mass reduction ensures the proper operation of pistols even with low-impulse ammunition. 
     For the use of small caliber ammunition mentioned above fired from weapons which are actually intended for larger calibers with respect to the handle piece and the exterior dimensions of the breech, the design of a barrel as illustrated in  FIG. 5  is proposed in an advantageous embodiment in a systematic upgrade of the inventive idea. The barrel part  2  includes a basic part  6  made of commonly used steel and a plastic barrel  7  enveloping the largest part. As clearly seen in  FIG. 10  illustrating a cross section through the axis of symmetry of the barrel piece  2 , the barrel axis  8  is tilted compared to the top most generatrix or outlining edge  9  of the barrel envelope  7 , whose exterior contours correspond to the contour of the barrel part when using traditional ammunition and traditional calibers. This means that the barrel part  2  corresponds to an “original” barrel part in terms of its exterior dimensions and its appearance, except for the fact that the plastic material has a clearly different visual appearance than the metal, while the arrangement of the barrel axis  8  and the design of the breech with a correspondingly smaller caliber is nevertheless possible. 
     The inclination between the barrel axis  8  and the parallel straight lines  9  relative to the “regular” barrel axis ensures that the fired bullet intersects the normal trajectory of a regular caliber weapon in the target area again with shorter training distances (e.g., 10 meters for pistols) and identical use and therefore the handling of the training weapon or a weapon with low-impulse ammunition also corresponds to the handling of a regular weapon. 
     As briefly mentioned above, the plastic parts around the metal parts can be molded in the fashion of lost cores; alternatively, they can be manufactured separately by attaching corresponding holder elements on the metal residues of the breech  3  and the barrel  6  in order to build the breech. 
       FIGS. 5 to 9  illustrate how these elements are designed in a preferred embodiment: 
       FIG. 5  shows the detail V of  FIG. 1  in the area of the front arc  15  of the residual metal breech  3 : this barrel arc  15  has a groove-shaped or pocket hole-like recess  10  on its abutting surface pointing back toward the breech, with the front abutting surface of the plastic barrel cover resting on said abutting surface, and with a ridge-shaped or hat-shaped projection  11 , originating from the abutting surface of the barrel cover  4 , extending into said recess and preferably snapping in under light prestress (compression). 
     If the recess  10  is designed groove-shaped and hence the projection  11  is designed ridge-shaped, these two elements essentially extend across almost the entire area of the inner width of the residual breech  3 . If the front bracket  15  in the direction of the barrel axis is designed particularly thin so that almost no substance remains in the top most area above the highest generatrix of the barrel part  2 , it is advantageous to provide two shorter or pot-like recesses on the left and right of the middle plane instead of the groove-shaped recess  10  and to adjust the shape and dimension of the recess or recesses  11  accordingly. 
       FIG. 6  shows the detail VI of  FIG. 1 , hence if looking at the top view of the slide according to  FIG. 3 , it shows area  12 . As seen in  FIG. 6 , the same procedure as for the barrel arc  15  was implemented in the region of the breech arc  16 , except that here, because of the offset of the transverse pitch into sections  12  and  12 ′ ( FIG. 3 ), it is innately necessary to bisect both the recess  10  as well as the projection  11 . Whether they subsequently have a more groove-shaped or a more pot-shaped design and are possibly divided once more is a question the designer will easily be able to answer based on the design criteria available to him/her and the advantages or disadvantages associated with the manufacture of the shapes for the plastic part and the incorporation of the recesses into the metal part. 
       FIG. 7  shows section VII-VII of  FIG. 2  normal relative to the axis of the weapon, which would also be normal relative to the barrel axis  8  with a “regular” design, but which is considered normal relative to the generatrix  9  ( FIG. 10 ) in this case. As seen in this figure, the barrel cover  4  made of plastic forms the largest part of the breech surface and the sheathing in this large area of the breech, while the metal residue  3  of the slide in this area is reduced to the two longitudinal bars  13  with a small cross section, said cross section forming the guides (without reference numbers) arranged in the lower area for the counterstays on the handle piece and comprising longitudinal grooves on the side facing the plastic, said longitudinal grooves being clearly visible in  FIG. 9  which once again shows the enlarged detail IX of  FIG. 7 : a ridge-shaped projection  11  of the barrel cover  4  made of plastic projects into said grooves  10 . 
       FIG. 8  illustrates the detail VIII of  FIG. 4 . It is the back end of the right bar  13  (always relative to the normal hold of the weapon while in use) and comprises an undercut for retaining the plastic part  4  in the residual metal breech  3 , with a bulge of the plastic part inserted into said undercut and hence absorbing longitudinal forces on this side of the cover part  4  without being able to break away. 
     Finally,  FIG. 11  shows a kind of vertical exploded sketch of the two cover parts  4  and  5  made of plastic, the residual slide  3  made of metal and the assembled barrel part  2  underneath, whereby the shoulder of the plastic sheath surrounding the metal barrel is clearly visible for the barrel part  2 . Other components of the pistol relating to a striking pin safety mechanism and a back cover of the slide  3  are also illustrated in  FIG. 11 ; however, they are not associated with the invention and are therefore not labeled with reference numbers. 
     Finally, for the sake of completeness, these parts are illustrated in normal, assembled condition placed on a handle part  19  in  FIG. 12 . 
     The invention is not restricted to the illustrated exemplary embodiment, but it can be modified in different ways. For instance, the plastic parts and the residual metal slide can be connected differently, for example by way of gluing, and the size of the areas of the covers of the slide replaced with plastic can vary, especially with respect to the different designs of known pistols, which comprise different mass distributions between the breech, guide area of the slide, cover of the barrel and breech, etc. 
     The only essential condition is that the parts of the “original” slide, which are used as guides, as an impact base, as contact areas in the region of the breech or as contact elements in the region of the ejection port for whatever components or projectile parts, are still made of metal and must have a sufficient amount of substance to ensure the mechanical stability. 
     It is obviously necessary to always base the different applications on the specific weapon for which a training weapon is to be created. This special normal weapon is used to define the area of the slide to be replaced with plastic in order to achieve the mass reduction which a person skilled in the art can easily calculate with the knowledge of the selected training ammunition. Said area of the slide is subsequently defined based on the criteria: reduction where the guide on the handle piece is not impaired and in such a way that the mechanical stability of the slide is not impaired. 
     Any plastic can be used which is capable of withstanding the expected thermal and mechanical exposures. The growing use of plastic for firearms in recent years provides the person skilled in the art with a host of potential plastics, including PA66 as an example.