Patent Publication Number: US-8117956-B2

Title: Magazine for a hand gun

Description:
RELATED APPLICATIONS 
     This application claims priority from German Application No. DE 10 2010 009 186.3, filed Feb. 24, 2010, which is herein incorporated by reference in its entirety for all purposes. 
     FIELD OF THE INVENTION 
     The present invention relates to a magazine for a hand firearm, which is detachably mountable to the weapon, incorporating a drum-like, approximately cylindrical housing which accommodates a greater number of cartridges in an orientation parallel to the axis of the housing, further incorporating an approximately spiral-shaped divider device, which is located inside the housing and accommodates the cartridges, a driver plate, which is adapted for indexed rotation about its axis and is driven by the force of a spring, said driver plate causing the cartridges to advance to the next position on a spiral path after each shot, and a follower disposed in the magazine, which causes the cartridges to advance on their spiral path, to exit said divider device and to enter into a magazine head. 
     BACKGROUND OF THE INVENTION 
     What are referred to as drum magazines have long been known in prior art. In this context, the reader is referred to U.S. Pat. No. 2,131,412 for instance. Generally, said drum magazines incorporate a drum housing inside of which there is carried a greater number of for example 50 or more cartridges in an orientation parallel to the axis of the drum housing. The cartridges are conveyed on a spiral path by a follower into a magazine head, said follower advancing by the width of one cartridge after each shot via a mechanism operating under the action of a spring. A spiral spring that can be wound up in the fashion of a mainspring can be used as the spring for example. At need, the drum magazine may be attached to various types of weapons via an adapter. 
     Another drum magazine having the features of the type mentioned herein above is known from U.S. Pat. No. 4,926,742 A wherein the follower, whose one end engages behind the last cartridge in the magazine and pushes the cartridges on their spiral path through the housing, is articulated to the rotatable driver plate in the region of its other end. Thus, in principle, the head of the follower moves on the same spiral path as the cartridges while the end of the follower, which is articulated to the driver plate, always moves on an exterior circular path together with the driver plate, so that the angular position of the follower changes as a function of the filling level of the magazine. Since the mechanics used with this prior art drum magazine is quite complex, the feeding and ejection of the cartridges, which occurs in very short intervals when in use, may be subject to failures. In particular the introduction of forces is disadvantageous due to the pivotal attachment of the follower in the outer region of the driver plate. A force component is thus generated, which presses the follower outward against the wall of the divider device, thus causing friction forces to generate and possibly the follower to get jammed. 
     SUMMARY OF THE INVENTION 
     It is the object of the present invention to provide a magazine for a hand gun of the type mentioned herein above, which ensures failure-free movement of the feeding mechanics for the cartridges. 
     The solution to this object is a magazine for a hand gun of the type mentioned herein above, which has the characterizing features of the main claim. 
     In accordance with the invention, there is provided that the entire follower moves behind the last cartridge stored in the magazine on the spiral feeding path through the divider device, that the follower is not connected solidly to the driver plate but radially displaceably instead, and that said follower glides radially outward in a guide of the driver plate while being forwarded. 
     This implementation of the invention, in terms of construction, of essential components of the feeding mechanics, namely of the follower and of its attachment to the driver plate leads to an advantageous balance of forces. In the spiral feeding path, the follower moves so that the main force component acts in the feeding direction onto the respective last cartridge stored in the magazine. Forces acting outward upon the wall of the divider are avoided. When the cartridges, and together with them the follower, move through the spiral path of the divider on their feeding path, the follower progressively moves farther outward in the radial direction in its guide, thereby performing a kind of gliding movement. As contrasted with prior art, there is no longer any solid attachment point to which the follower is connected to the driver plate and which determines the forces acting onto the follower; instead, depending on the respective position of the follower on the spiral path on which the cartridges progressively move outward as the magazine is getting empty, the follower glides outward to the same extent in a guided movement. Accordingly, the forces applied by the follower always act in the feeding direction of the cartridges so that the follower is prevented from wedging or jamming. 
     According to a preferred developed implementation of the present invention, there is provided that the driver plate has a radial slot serving as a guide for the follower and in which the follower is hung for radial gliding movement. The radial width of the follower thereby approximately fits into the slot of the driver plate, which is of the same width; in an upper region for example, the width of the follower protrudes from said slot, though. If there remains enough clearance for the follower in the slot width, said follower can then glide radially outward in this slot as it progressively moves on the spiral path. 
     The follower may for example incorporate a plurality of links that are movably joined together or that are loosely disposed one behind the other in the spiral feeding path, said links being formed and dimensioned similar to a cartridge. In the first case mentioned, it is a kind of link chain that moves through the divider on said spiral path, in the feeding direction behind the cartridges stored in the magazine, the different links of the chain being linked together. According to the second alternative, it is also possible to use loose elements having approximately the shape of a cartridge, said elements however being blind cartridges without charge and primer and being of dimensions slightly larger than the cartridges themselves so that it is possible to prevent the elements of the follower from being ejected from the magazine through the magazine head. 
     According to a preferred developed implementation of the solution to the invention, the drum magazine of the invention is being used for cartridges having an ignition edge as they are being used for smaller weapon calibres. In this case, it is possible to suspend the cartridges from the top into slots of the driver plate during loading in such a manner that the ignition edge rests on a surface of the driver plate, while the remaining diameter of the cartridge, which is reduced with respect to the ignition edge, is accommodated in the slot. This allows for fast and simple loading of the magazine after which the cartridges are disposed in the slots so as to be oriented in the intended position, each slot of the driver plate only being capable to accommodate one cartridge in its width but several cartridges in the radial direction so that, when the magazine is full, the cartridges are positioned in individual rows in the driver plate, said rows extending radially from the inside toward the outside, each radially adjacent cartridge lying in another row of the spiral-shaped divider in such an individual row so that radially adjacent cartridges are separated from each other by a wall of the divider. By contrast, cartridges of two neighbouring slots, which are disposed next to each other in the circumferential direction, are separated from each other by webs of the driver plate that are disposed between two respective slots. Upon rotation of the driver plate, all the cartridges stored in the magazine are caused to move in the circumferential direction and are urged to the next position, a respective cartridge leaving the drum and being caused to enter the magazine head mounted to said drum. 
     A preferred developed implementation of the solution to the invention intends to dimension the diameter and/or the axial length of the various links of the follower so as to be slightly larger than the cartridges to be stored. In this embodiment, the cartridges can be forwarded one after the other from the drum to the magazine head until the follower has forwarded the last cartridge into the magazine head. The links or the various elements of the follower may then continue to forward the cartridges within the magazine head, this allowing to also evacuate the cartridges located in the magazine head. This process is repeated until the last cartridge has left the magazine head so that the magazine is completely empty. However, due to their dimensions and to a separate mechanism provided for this purpose, the links of the follower cannot leave the magazine head so that it is ensured that the links of the follower remain in the magazine head. Then, the magazine can be again loaded with cartridges. 
     In a preferred developed implementation of the invention there is provided that the magazine head is exchangeably fastened to the housing of the magazine through fastening means. The advantage thereof is that the magazine head can be exchanged and that the same drum magazine can be used for various types of weapons. The magazine head may be changed via a screw connection that may be untightened for example. 
     It is particularly preferred that the magazine incorporates a housing cover, which can be removed from the housing of the magazine, and that a loading plate is disposed between housing cover and driver plate. 
     The features mentioned in the dependent claims relate to preferred developed implementations of the solution to the invention. Other advantages of the invention will become apparent in the detailed description given herein after. 
     The present invention will be described herein after in closer detail, using exemplary embodiments thereof, with reference to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In said drawing: 
         FIG. 1  shows a perspective exploded view of a drum magazine of the invention, given by way of example; 
         FIG. 2  shows a top view of a drum magazine of the invention, when mounted; 
         FIG. 3  shows a side view of the drum magazine shown in  FIG. 2 ; 
         FIG. 4  shows a perspective view of the drum magazine of  FIGS. 2 and 3 ; 
         FIG. 5  is a top view of the housing of the magazine, which is open at the top and is loaded with a number of cartridges; 
         FIG. 6  is a view similar to  FIG. 5 , but with the driver plate omitted; 
         FIG. 7  is a view similar to  FIG. 5  but in another position of the follower and with less cartridges in the magazine; 
         FIG. 8  is a view similar to  FIG. 5  but again in another position of the follower and with the magazine almost empty; 
         FIG. 9  is a sectional view of the empty magazine according to the position shown in  FIG. 8 ; 
         FIG. 10  is a top view of the housing open at the top of a partially filled magazine according to an alternative implementation variant of the invention, slightly amended; 
         FIG. 11  is a corresponding top view like in  FIG. 10 , but without the driver plate; 
         FIG. 12  is a view similar to  FIG. 11 , but with the drum magazine empty. 
     
    
    
     DETAILED DESCRIPTION 
     At first, reference is made to  FIG. 1 . The illustration shows an exploded perspective view of the essential component parts of a drum magazine of the invention. Said drum magazine incorporates an approximately cylindrical housing  10 , a driving spring (torsion spring)  12 , the function of which is similar to that of a mainspring and by means of which the drum magazine is caused to rotate in order to eject the cartridges. Further, there is provided a housing axis  13 , a driver plate  14  with a great number of slots made on its circumference, a loading plate  15  as well as a housing cover  16  by means of which the housing  10  is closed at its top. A magazine head  21  is adapted to be detachably mounted to the housing  10  via fastening means  23 , said magazine head being in turn mounted to the handle (not shown herein) of a weapon. The cartridges are ejected via the magazine head  21 . The housing  10  has a divider device  9  with several partition walls forming a spiral arrangement. The cartridges are accommodated between these partition walls of the divider device  9  so that a spiral-shaped feeding path  8  forms on which the cartridges are transported from radially inside to radially outside until they are ejected from the drum housing  10  and enter the magazine head after having performed several complete movements about the circumference of the magazine in the region  7 , where the magazine head  21  is mounted. In order to forward the cartridges on this spiral-shaped feeding path, they are guided almost one by one in the driver plate  14 , a follower  18  being provided behind the last cartridge  20   a  which also moves on the approximately spiral-shaped feeding path for emptying the magazine, but moving behind the last cartridge  20   a  as far as into the magazine head  21  where it pushes said last cartridge out of the magazine head  21 . 
     Herein after, reference will be made to  FIG. 2 , which shows a top view of an exemplary drum magazine in accordance with the present invention. It shows the closed housing  10  with a housing cover  16  from the top. It appears that this housing cover  16  has a recess  17  in the shape of a segment of a circle so that it is possible to look into the interior of the magazine in one segment and to view the loading plate  15  located underneath said housing cover  16 . The driver plate  14  is rotated clockwise during loading by means of said loading plate  15  so that the cartridges  20  are allowed to glide into the slots  22  of the driver plate  14  and the magazine is wound up at the same time. One also sees the magazine head  21 , which is fastened to the housing  10  and mounted to the firearm by pushing the magazine head  21  into a handle of the weapon for example. Moreover,  FIG. 2  shows the four screws  19  by means of which the housing cover  16  is fastened; after having removed said screws, the housing cover  16  can be removed from the housing  10 . 
     The side view of the housing  10  as shown in  FIG. 3  also shows the removable housing cover  16  and the magazine head  21 , which is fastened to the housing, possibly so as to be exchangeable against another magazine head for another type of weapon. 
     Referring now to the  FIGS. 5 through 9 , the function of the drum magazine of the invention will be discussed in closer detail herein after.  FIG. 5  is a top view of the magazine filled with cartridges, once the housing cover  16  has been removed. It appears that the full magazine easily accommodates 110 cartridges  20 , these cartridges having an ignition edge and being intended for a small-calibre weapon; they are hung by the ignition edge from the top into slots  22  of the driver plate  14 . A plurality of such radially oriented slots  22  are provided, which are spaced a distance apart and which, in principle, extend over the entire circumference of the driver plate. The cartridges  20  are arranged such that several cartridges  20  are accommodated in a respective row in each of the slots  22 . In the illustration shown in  FIG. 6 , the driver plate  14  was omitted so that it appears that the cartridges lie in the magazine in a generally almost spiral-shaped path, this being obtained by the partition walls of the divider device  9  (see also  FIG. 1 ). These partition walls are the inner partition wall  9   a , the partition wall  9   b , which is parallel thereto and lies radially further toward the outside, the partition wall  9   c , which in turn is parallel to the latter partition wall and which lies even further radially outside and the outermost partition wall  9   d , which adjoins the outer housing wall. The two central partition walls  9   b  and  9   c  have an outward oriented offset at one point on the circumference, thus forming the almost spiral-shaped feeding path of the cartridges which thus migrate radially toward the outside as the magazine is emptying. Therefore, the cartridges  20  located in the innermost row are first located between the two partition walls  9   a  and  9   b . After one complete revolution, the cartridges  20  then lie between the two central partition walls  9   b  and  9   c  in a central row that extends in turn over almost the entire circumference of the divider device  9 . Finally, the cartridges  20  lie in an outermost row between the central partition wall  9   c  and the outer partition wall  9   d  until they finally enter into the magazine head  21 . As a result, one obtains three rows of cartridges  20 , the feeding path following an almost spiral-shaped path as the drum magazine empties progressively. 
       FIG. 6  also shows the follower  18 , which in this variant consists of a number of cylindrical elements having approximately the dimensions of a cartridge  20  and moving like the cartridges  20  in the spiral-shaped feeding path, the follower  18  applying a pressure against the last cartridge  20   a  with its foremost element  18   a  when seen in the feeding direction. It appears from  FIG. 5  that the elements of the follower  18  are respectively accommodated in the slots  22  of the driver plate  14  like the cartridges  20 . 
     The functioning of the magazine while emptying will be best understood when comparing the  FIGS. 5 ,  7  and  8 . It appears that the driver plate  14  has performed one complete and one three-quarter turn between the position shown in  FIG. 5  and the one shown in  FIG. 7 . This is obvious from the respective position of the follower  18  and of the last cartridge  20   a . In  FIG. 7 , said last cartridge is located in the region of the offset between the central and the outermost row of the feeding path. The cartridges which then leave the outermost row of the feeding path glide from the respective one of the slots  22  of the guide plate  14  and enter into a channel of the magazine head  21 , where they fit snugly against each other as can be seen in  FIG. 7  (see cartridges  20   b ,  20   c ). If one compares with the illustration shown in  FIG. 8 , the guide plate  14  has performed slightly more than one complete turn when compared with  FIG. 7  so that now there are no cartridges left in the housing  10  of the drum magazine and that the follower  18  is still partially in the feeding path of the drum magazine while partially already being in the channel of the magazine head  21 . The last cartridge  20   a , which is provided with reference numerals in the  FIGS. 5 and 7  as well, is located in the position shown in  FIG. 8  already in the upper region of the magazine head  21  in which, as can be seen, there are only two cartridges left. Through the follower  18 , all the cartridges can be ejected from the drum magazine and also from the magazine head  21 . As can be seen from the comparison between the  FIGS. 5 and 7 , the elements  18  of the follower move progressively radially outward in the corresponding slots  22  of the driver plate  14  when said follower moves on the approximately spiral-shaped feeding path. 
     As can be seen from  FIG. 9 , the discrete elements of the follower  18  are of a design which is slightly different from that of the cartridges  20 . The elements of the follower have another geometry than a cartridge  20 , here for example a central constriction  24 , so that they are narrower than the cartridges  20  in their center, this only by way of example, an appropriate mechanism or a suited geometry allowing to prevent the elements  18  of the follower from leaving the magazine head  21 . In  FIG. 9 , it also appears that both the cartridges  20  and the elements of the follower  18  are hung in the driver plate  14  so that these elements slightly protrude toward the top. The ignition edge of the cartridges  20  in the magazine therefore lies on the top surface of the driver plate  14 . 
     In the sectional view through the housing  10  of the drum magazine as shown in  FIG. 9 , the driving spring  12 , which is also shown in  FIG. 1 , and which functions like a mainspring and causes the driver plate  14  to rotate about its axis after biasing can also be seen. For this purpose, the driving spring  12  is carried on the axis  13  and is retained in this axis in a slot by one end for example. 
     Referring to the  FIGS. 10 to 12 , a slightly amended implementation variant of the present invention will be described herein after. This variant differs from the exemplary embodiment described herein above by the configuration of the follower  18 . Here, the elements are not discrete, loose elements; instead, the elements of the follower  18  are linked together to form a unit like a link chain, said unit urging the cartridges  20  on their approximately spiral-shaped feeding path through the divider device toward the magazine head  21 . In  FIG. 11 , the follower  18  is particularly visible since the driver plate  14 , which is disposed on top of it when the magazine is mounted, has been omitted therein whilst in  FIG. 10  the driver plate  14  is shown so that the follower  18  can only be seen in parts. Both illustrations show a position of the follower  18  in which the drum magazine is only partially filled with cartridges  20 . Again, the last cartridge  20   a  in the feeding path is indicated at  20   a . This cartridge is located in a position in which it lies in the region of the offset and in which it moves from the central to the outer circumferential row of the feeding path. The follower  18  consists of several elements of like configuration although it also has elements of a slightly different configuration that are located at its respective ends as well as an element  18   b  (see  FIG. 10 ) which serves to fasten the follower  18  inside a slot  26  of the driver plate  14  by suspending it therein. 
     As can be seen from  FIG. 10 , there is a difference between the follower plate  14  and the variant described herein above since said plate has a slightly wider web  27  at one point of the circumference between two slots  22  that are open toward the outside so that the distance between these two slots  22  is slightly greater. Accordingly, the time needed for the next cartridge  20  to enter into the magazine head  21  is minimally longer when the driver plate  14  passes this point to which the magazine head  21  is mounted during its movement of rotation. At this point, the cartridges  20  then leave the outermost of the circumferential rows of the divider device  9  and move from the slightly spiral-shaped feeding path into the channel of the magazine head  21  (see  FIG. 11 ).  FIG. 12  shows the position with the empty drum magazine in which the driver  18  has performed slightly more than one additional turn as compared with the position shown in  FIG. 11  and in which the last cartridge  20   a  already is in the magazine head  21  which it leaves shortly thereafter. In  FIG. 12  it can be seen that the follower  18  with its linked elements (links) migrates into the channel of the magazine head so that all the cartridges  20  can be evacuated from the magazine. When the follower  18  moves through the divider device  9  behind the cartridges  20  on the feeding path as the magazine is getting empty, the element  18   b  of the follower  18  glides progressively outward in the slot  26  in which the follower  18  is fastened. 
     LIST OF NUMERALS 
     
         
           8  spiral-shaped feeding path 
           9  divider device 
           10  housing 
           12  driving spring 
           13  axis 
           14  driver plate 
           15  loading plate 
           16  housing cover 
           17  recess 
           18  follower 
           18   b  fastened element of the follower 
           19  screws 
           20  cartridges 
           20   a  last cartridge 
           21  magazine head 
           22  slots 
           23  fastening means 
           24  constriction 
           25  slot 
           26  slot 
           27  web