Abstract:
The invention relates to a stock mounting device for fixing a stock on a receiver of a small arm that includes a clamping pin, and a clamping cam cooperating with the clamping pin, by which the shank can be mounted on the receiver by generating an axial force.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. §119 to German Patent Application No. 10 2011 114 687.7 filed Oct. 4, 2011, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to stock mounting device for a small arm. The invention further relates to a small arm with such a stock mounting device. 
     BACKGROUND OF THE INVENTION 
     In previously known small arms, the stocks, typically consisting of wood or plastic, are generally fixed to the action or receiver by means of special threaded screws. One disadvantage of this mounting is that several turns of the threaded screws are required in order to mount or detach the barrel, which is connected with a corresponding expenditure of time and assembly work. The threaded screws can also be lost while in use. 
     SUMMARY OF THE INVENTION 
     One object of the invention is to create a stock mounting device and a small arm with such a stock mounting device that allow easy and fast mounting or detachment of a stock. 
     This problem is solved by a stock mounting device as set forth herein and by a small arm with the characteristics as also set forth herein. Expedient configurations and advantageous refinements of the invention are also disclosed. 
     The stock mounting device according to the invention consists of a clamping pin and a clamping cam cooperating with the clamping pin, by means of which the stock can be mounted on the receiver by generating an axial tensile force. The clamping cam comprises a central though-hole for passage of a tensioning head of the clamping pin and at least one lateral slot for receiving a slimmer area of the clamping pin. Thereby the clamping pin can be pushed through the clamping cam and the clamping cam can be rotated into a clamping position. A quick-release fastener that allows fast and secure mounting and dismounting of the stock without laborious assembly work is made possible by the clamping cam and the associated clamping pin. In comparison to the usual mounting screws, the clamping cam need only be rotated by one quarter turn in order to effect clamping or releasing. A fixed clamped position can additionally be specified by the clamping cam, so that excessively weak or strong tightening of the stock and associated inaccuracies or warping can be avoided. In addition, the clamping cam and the clamping pin remain mounted on the parts to be connected even when the stock is released, so that they cannot be lost even during dismounting of the stock in the field. 
     In an advantageous configuration, the clamping pin is arranged on the receiver, and the clamping cam in the stock. In order to mount a front stock, for example, the clamping cam can be arranged in the front stock rotatably about an axis perpendicular to the longitudinal axis of the stock. The clamping cam is expediently accommodated on a baseplate inside a housing. The clamping cam can also be arranged in the stock without a separate housing, however. 
     The clamping cam preferably has at least one eccentric clamping face on its outer side for contacting a tightening face of the clamping pin. In this way, an axial retraction force can be generated between the clamping cam and the clamping pin. The clamping cam can also be constructed symmetrically, however, and have two opposing eccentric clamping faces and two opposing slots. Then it is not necessary to take account of any special installation position when mounting the clamping cam. 
     A locking device for preventing an undesired rotation of the clamping cam can be arranged on the clamping cam. For example, the clamping device can be an actuating element, form-fit to the clamping cam and axially movable between a locking position and an actuation position, that can only be rotated in the actuation position. This can be achieved in an expedient embodiment in that the actuating element has a head constructed as a hexagon and a slimmer shank located underneath the head, and runs through an opening constructed as a slotted hole of a baseplate in such a manner that the head is held secured against rotation in the locking position inside the opening, and in the actuating position, the shank moves into the area of the opening in order to rotate the actuation element. 
     In another expedient embodiment, the clamping pin can be mounted on the receiver via a mounting element. The mounting element can be arranged, pivotable between a stock mounting position and a barrel mounting position, in a slot of a barrel receptacle of the receiver constructed as a slotted sleeve, and can be constructed in the form of a wedge in such a manner the barrel receptacle is widened in the barrel-mounted position. Thereby the mounting element is not only able to take on the retention of the clamping pin, but can also take over the function of an installation aid for mounting and dismounting the barrel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional details and advantages of the invention emerge from the following description of a preferred embodiment with reference to the drawings. Therein: 
         FIG. 1  illustrates a receiver of a repeating rifle with a stock mounting device according to the invention for fixing a front stock on the receiver; 
         FIG. 2  illustrates the stock mounting device of  FIG. 1  without its housing; 
         FIG. 3  illustrates a detail view of the stock mounting device with an actuating element in a locked position; 
         FIG. 4  illustrates a detail view of the stock mounting device with the actuating element in the actuation position; 
         FIG. 5  illustrates the stock mounting device with a clamping cam in a releasing position in cross section; 
         FIG. 6  illustrates the stock mounting device with the clamping cam of  FIG. 5  in a releasing position in cross section; 
         FIG. 7  illustrates a bottom view of a receiver with a mounting element for the stock mounting device in a stock mounting position; and 
         FIG. 8  illustrates a bottom view of the receiver with the mounting element for the stock mounting device in a barrel mounting position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The stock mounting device  1  shown in different views in  FIGS. 1-6  contains a clamping pin  3  mounted on an action or receiver  2  of a repeating rifle and a clamping cam  4  in accordance with  FIG. 2  that can be arranged according to  FIG. 5 , for example, in the front stock  5  of the repeating rifle. The front stock  5  can be fixed on the receiver  2  by means of the clamping pin  3  and the clamping cam  4 . 
     As can be seen in  FIGS. 5 and 6 , the clamping cam  4  is arranged inside the front stock  5  rotatably about an axis perpendicular to the longitudinal axis of the stock  5 . The clamping cam  4  is arranged inside a housing  6  on a base plate  7  recognizable in  FIG. 2  so as to be rotatable between a released position shown in  FIG. 5  and a clamping position shown in  FIG. 6 . The base plate  7  and the housing  6  with the clamping cam  4  arranged therein are mounted via holes  8  and screws  9  recognizable in  FIG. 2  in a corresponding recess  10  of the front stock  5 . A through-hole  11  for introducing the clamping pin  3  is provided in the housing  6 . 
     A passage  12 , aligned with the opening  11 , for introducing the clamping pin  3  is also situated in the stock  5 . The clamping pin  3  mounted at the front end of the receiver  2  is arranged in the assembled position so as to project forward in the direction of the longitudinal axis of the receiver  2 , and has a tensioning head  13  at its front end and an adjoining slimmer area  14 . In the clamped position shown in  FIG. 6 , the clamping pin  3  projects through the clamping cam  4  and the tensioning head  13  is opposite the clamping cam  4 . 
     The clamping cam  4  shown in  FIG. 2  and  FIGS. 5 and 6  contains a central through-hole  15  running perpendicular to its axis of rotation and two diametrically opposed lateral slots  16  and  17  which extend up to a respective web  18  and  19 . The through-hole  15  has a somewhat larger inside diameter than the outside diameter of the tensioning head  13 , so that the tensioning head  13  can be pushed completely through the clamping cam  4 . The slots  16  and  17  have a somewhat larger width than the slimmer area  14  on the clamping pin  3 . The slots  16  and  17  are constructed in such a manner that the clamping cam  4  can be rotated by approx. 90° with clamping pin  3  inserted. On the outside of the clamping cam  4 , at least one eccentric clamping face  20 , spiral-shaped for example, is provided, which comes into contact with an inner tightening face  22  on the inner side of the tensioning head  13  in case of a rotation of the clamping cam  4  into the clamping position and generates an axial retraction force between the clamping pin  3  and the clamping cam  4 . 
     In the embodiment shown, the clamping cam  4  is constructed symmetrically with two opposing clamping faces  20  and  21  and two lateral receptacle slots  16  and  17 . Thereby the clamping cam  4  can be installed in two positions. The clamping cam  4 , however, can also have only one clamping face  20  and one associated receptacle slot  16 . 
     The clamping cam  4  is rotated by a bolt-like actuating element  23 , rotatably arranged inside the stock  5  coaxially with the axis of rotation of the clamping cam  4  and movable axially, that can be moved axially against the force of a compression spring  24  between a lower locking position shown in  FIG. 3  and an upper actuation position shown in  FIG. 4 . The actuation element  23 , rotatable by an Allen wrench or another suitable tool, contains an upper part projecting through an opening  25  in the base plate  7  with a head  26  constructed as a hexagon and a slimmer cylindrical shank  38  below it, which is recognizable in  FIG. 4 . 
     In order to rotate the clamping cam  4 , the hexagon-shaped head  26  positively engages in a recess shaped as a hexagon socket on the underside of the clamping cam  4 . The opening  25  is constructed as a slotted hole with a width that is only slightly larger than the wrench size of the hexagon-shaped head  26 . Thus, if the hexagon-shaped head  26  is in the area of the opening  25  in the baseplate  7 , the actuating element  23  cannot be rotated. The slimmer shank  38  underneath the head  26  is arranged in such a manner that it only comes into the area of the opening  25 , constructed as a slotted hole, of the baseplate  7  in case of a displacement of the actuating element  23  into the upper actuation position, and thereby allows turning of the clamping cam  4 . On the other hand, if the actuating element  23  is pressed by the compression spring  24  into the lower locking position, the hexagonally shaped head  26  also comes into engagement with the opening  25  constructed as a slotted hole, whereby a rotation of the clamping cam  4  is prevented. The actuating element  23  must therefore be pushed in against the force of the compression spring  24  before the clamping cam  4  can be turned. This creates a locking device for preventing an undesired rotation of the clamping cam  4 . 
     In the embodiment shown in the drawing, the action or receiver  2  has a barrel receptacle  27  constructed as a slotted sleeve for detachable retention of a barrel  28 . The clamping pin  3  is connected via a bolt-like mounting element  29  to the receiver  2 . As follows from the bottom views in  FIGS. 7 and 8 , the barrel receptacle  27  contains a slot  30  and lateral holes  31 , visible in  FIG. 1 , via which the barrel receptacle  27  constructed as a slotted sleeve can be pressed together with the aid of clamping screws  32  to fix the barrel  28  in place. The mounting element  29  is arranged with its bilaterally flattened rear end  33  in the slot  30  so as to be rotatable about a transverse pin  34  recognizable in  FIG. 1  between a stock mounting position illustrated in  FIG. 7  and a barrel mounting position shown in  FIG. 8 . 
     The clamping pin  3  is screwed tightly into a threaded hole  35 , recognizable in  FIG. 8 , in the front end of the bolt-like mounting element  29 . The flattened rear end  33  of the mounting element  29  is constructed like a wedge in such a manner that the barrel receptacle  27  is spread open for easier mounting or dismounting of the barrel  28  when the mounting element  29  is pivoted into the position of  FIG. 8 . To accomplish this, it is possible to provide, on the end  33  of the mounting element that is articulated in the slot  30 , lateral wedge faces  36 , as can be seen in  FIG. 7 , that, if the mounting element  29  is pivoted into the position of  FIG. 8 , come to rest against a step-like shoulder  37  between a wider outer area and a narrower inner area of the slot  30 , and thereby spread open the barrel receptacle  27 . 
     In the shank mounting position of  FIG. 7 , the mounting element  29  is oriented according to  FIG. 1  in the longitudinal direction of the receiver  2 , so that the clamping pin  3  fastened in the mounting element  29  can be introduced into the clamping cam  4  when the front stock  5  contacts the receiver  2 . In the downward-pivoted barrel mounting position of  FIG. 8 , on the other hand, the barrel receptacle  27  is widened so that the barrel  28  can be more easily mounted and dismounted. The mounting element  29  therefore serves not only for retaining the clamping pin  3 , but can also take on the function of an assembly aid for mounting and dismounting the barrel  28 .