Patent Publication Number: US-2003221350-A1

Title: Loading device for kinetic operation automatic or semi-automatic rifles

Description:
[0001] The present invention refers to a loading device for kinetic operation automatic or semi-automatic rifles. The loading device for automatic or semi-automatic rifles can have different operating principles, based upon which we can distinguish:  
       [0002] gas recovery fixed barrel rifles, in which the gases generated by the firing of a cartridge are in part used to rearm a loading kinematism through a feeder mechanism equipped with a piston and a cylinder;  
       [0003] barrel recoil rifles (with a long or short recoil), in which the barrel, having the possibility of moving in the opposite direction to that in which the projectiles leave, determines a thrust and the actuation of the feeder mechanism, which, in turn, takes care of rearming the loading kinematism;  
       [0004] pump-action rifles, i.e. manual bolt-action rifles, in which the loading kinematism is actuated by the hand of the firer which pulls back a mobile shaft which is integral with the feeder mechanism;  
       [0005] inertia or kinetic fixed barrel rifles, in which the feeder mechanism which rearms the loading kinematism is actuated through the kinetic energy of the recoil (FIG. 1).  
       [0006] In particular, hereafter reference shall be made to a smooth-bore rifle equipped with a semi-automatic loading device with inertia or kinetic operating principle, i.e. a rifle equipped with a so-called mixed loading device (semi-automatic-pump), where the semi-automatic function is in any case determined by the kinetic principle.  
       [0007] For some time inertial or kinetic operation rifles have been on the market, an example of which is shown in FIG. 1, generally indicated with  11 .  
       [0008] Such conventional rifles have, in their breech area, a breechblock latch  13  of the breech itself and, moreover, a kinetic spring  14 , placed between the latch  13  and the rear element of the breechblock  12  with respect to the direction in which the rifle  11  is supposed to be held.  
       [0009] Following a shot, the breechblock  12  of the rifle  11 , from the closed position, due to the inertia force in the opposite direction to the recoil force, advances along a central axis of symmetry in the same direction as the fired projectiles, compressing the kinetic spring  14 . Such a kinetic spring  14 , compressed, accumulates energy which it releases at a second moment, expanding and causing the sliding back of the breechblock  12  in which the feeder mechanism slides, which rearms the loading kinematism. During the sliding back motion all of the kinematisms which carry out the operating cycle of the rifle  11  are actuated chronologically arranging them for another shot.  
       [0010] The kinetic spring  14 , which constitutes the essential element of kinetic loading devices and which determines the operating characteristics of the rifle  11 , in conventional embodiments is bound by strict geometric and dimensional limitations. This prevents its optimisation in terms of comfort for the firer and limited stresses for the firearm.  
       [0011] The purpose of the present invention is that of eliminating the aforementioned technical drawbacks, realising a loading device for kinetic operation automatic or semi-automatic rifles, which has reduced bulk and determines a less rigid and more optimised and gradual operation.  
       [0012] Another purpose of the invention is that of realising a loading device for kinetic operation automatic or semi-automatic rifles which is substantially simple, safe and reliable.  
       [0013] These and other purposes, according to the present invention, are accomplished by realising a loading device for kinetic operation automatic or semi-automatic rifles according to claim 1.  
       [0014] Other characteristics of the present invention are, moreover, defined in the subsequent claims.  
       [0015] As already stated previously, the prior art foresees kinetic or inertia operation semi-automatic firearms in which the kinetic rearming thrust is activated, even in different points, by springs which are spiral, disc or cup-shaped, indifferently, made from steel which may be more or less special.  
       [0016] It is clear that a spring of this type, according to its design, can be more or less rigid and with more varied parameters. All of its actions and behaviour are, however, essentially regulated by the general characteristics of the springs.  
       [0017] Regarding this, on kinetic operation firearms, the characteristics of the spring, although necessary for correct operation, determine some negative consequences which are now implicit and accepted for this type of operation.  
       [0018] Some of these negative components concern vibrations, action and rest times which are too violent and loading diagrams which are essentially linear and subject to the physical laws of springs.  
       [0019] The described negative effects for the user mean greater discomfort when firing and more difficulty in controlling the stability of the firearm during firing, especially if it is a light firearm.  
       [0020] Violent actions and vibrations also produce greater stresses for the mechanical components of the firearm, decreasing their average working life.  
       [0021] Therefore, it can be summarised that kinetic operation firearms, which represent an enormous advantage for constructive simplicity, lower costs and lower maintenance needs, on the other hand are not very comfortable when firing above all in rifles which the market requires to be ever lighter.  
       [0022] So far, however, the advantages which are achieved on kinetic firearms, with respect to other techniques, such as “gas recovery”, “with a long barrel recoil” or “with opening delay”, largely overcome the negative effects described previously.  
       [0023] The object of the present invention thus proposes adding to the indisputable advantages of the inertia system with further advantages of use of the firearm which is thus optimised in all aspects. 
     
    
    
     [0024] Further characteristics and advantages of a loading device for kinetic operation automatic or semi-automatic rifles, according to the present invention, shall become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings, in which:  
     [0025]FIG. 1 partially shows a section view of a rifle which adopts a loading device with conventional kinetic operating principle;  
     [0026]FIG. 2 partially shows a section view of a rifle which adopts a loading device with kinetic operating principle, according to the present invention;  
     [0027]FIG. 3 shows a Cartesian diagram relative to the curve of the force applied in relation to the squashing produced in a conventional spring;  
     [0028]FIG. 4 shows a Cartesian diagram relative to the curve of the force applied in relation to the squashing produced in an elastomer. 
    
    
     [0029]FIG. 2 shows, in particular, a loading device for kinetic operation automatic or semi-automatic rifles  11 , according to the present invention, where, inside a housing  23 , a breechblock  24  of a barrel  25  of the rifle  11  is housed so that it can slide.  
     [0030] The breechblock  24  is of the per se known type with a locking latch  26 , according to which the latch  26  is housed inside the breechblock  24  and has a tooth-shaped protrusion  27 , which can engage in a recess of a portion of the housing  23  to close tight a chamber of the barrel  25  of the rifle  11 .  
     [0031] Inside the breechblock  24 , moreover, a firing pin  29  is housed which, in known embodiments, is equipped with suitable springs (not illustrated in the figures for the sake of simplicity) for keeping it in rest position.  
     [0032] The breechblock  24  is functionally associated with a feeder mechanism  22  through a loading kinematism, which is not shown for the sake of simplicity.  
     [0033] The feeder mechanism  22  comprises a tubular tank  31  with one end equipped with a cartridge feeding opening and an opposite end equipped with a blind base.  
     [0034] The cartridge feeding opening of the tank  31  is integral with the housing  23 , locked in a sleeve extension thereof  32 . On the front of the extension  32  are placed a folding lever  33 , which locks the cartridges  34  inside the tank  31 , by means of a tailpiece which interferes with a base portion of the cartridges  34  themselves, and a lifter  35 , suitable for carrying the cartridges  34  fed from the tank  31  into a position at the front of the barrel  25 . The blind base is realised through a plug extension  36  of a shaft  37 , which carries a knob  38  at a free front end thereof.  
     [0035] The plug extension  36  is screwed onto the body of the tank  31  and carries a spring  39  equipped at its free end with a plug  40 , which pushes the cartridges  34  contained in it towards the outlet opening of the tank  31 .  
     [0036] The shaft  37  is supported in a through-hole formed on a ring  41  for attaching the barrel  25  to the housing  23  and in a bushed seat  42  formed in a front portion of the housing  23 , integral with the ring  41  of the barrel  25 .  
     [0037] On the tank  31  and in abutment against the extension  32  of the housing  23 , a spring  43  is inserted, locked at an opposite end by a shaped bush  44 .  
     [0038] The bush  44  has a groove, in which a per se known tailpiece  46  for the connection of a loading kinematism is inserted.  
     [0039] On the shaft  37  and in abutment against the ring  41 , the feeder mechanism  30 , according to the invention, carries a synthetic element  15 , in particular made from an elastomer, inserted inside a blind hole of a swing block  30 .  
     [0040] The elastomer  15  is able to accumulate part of the inertia energy of the recoil of the rifle, whereas the swing block  30  is arranged in a frontal position with respect to the bush  44  which is operatively connected to the breechblock  24 , through the tailpiece  46  of the loading kinematism.  
     [0041] The use of a synthetic element from the elastomer family allows the actions and responses during firing to be adjusted, changing the form of the elastomer, so as to control the behaviour acting upon load diagrams which are variable according to rules dependent exclusively upon design requirements.  
     [0042] To this can be added the characteristics of elastomers themselves, which allow the reduction in vibrations and allow softer movements to be obtained, reducing the exasperation of the behaviour of metal elements.  
     [0043]FIGS. 3 and 4 show the behavioural differences of an elastomer with respect, for example, to a conventional steel spring. From this it can be deduced that, in a conventional spring, the load S (squashing produced) is proportional, according to a variable angle α, to the force F applied (line R of the Cartesian diagram of FIG. 3), whereas in the case of an elastomer the relationship between load S and force F applied is non-linear (curves H and K of FIG. 4).  
     [0044] It is clear, therefore, that by using the elastomer  15  it is possible, for example, to divide the reloading action of the rifle  11  into different behaviours, such as rapid action and breaking action, by simply studying the shapes, the sections and the couplings of the elastomer element.  
     [0045] Such a possibility, which is extremely important for a firearm intended to fire ammunition of various powers, allows both the highly elastic behaviour (for small powers) and stronger behaviour (for powerful loads) to be exploited, so as to dissipate part of the excess power, which determines greater stress.  
     [0046] Indeed, at the time of firing the recoil of the rifle causes the translation of the swing block  30 , by inertia, in the same direction as the projectiles fired, causing the compression of the elastic element  15 .  
     [0047] Then the elastomer  15  expands releasing the accumulated energy and pushing back the swing block  30 , which goes into abutment against the bush  44  which, in turn, makes the breechblock  24  translate, through the loading kinematism. The motion of the breechblock  24  then causes the actuation of the kinematisms which complete the operation of the rifle and arrange them for another shot.  
     [0048] From the description which has been made the characteristics of the loading device for kinetic operation automatic or semi-automatic rifles, object of the present invention, are clear, just as the advantages are also clear.  
     [0049] In particular, the embodiment in variable shapes and sizes, according to the requirements of the firearm, of a loading device for a smooth-bore semi-automatic rifle, comprising an element made from composite material of the elastomer family, allows operation of the rifle which is not very rigid to be obtained, with advantages in terms of less stresses on the firearm and good comfort for the shooter.  
     [0050] The element can also be made from synthetic material, as a single piece or in combination with other operating systems, for example in combination with gas recovery, short barrel-recoil or opening delay systems. The elastomeric element also in these cases optimises the behaviour of the firearm, integrating it with the systems described previously and, moreover, can also be used mixed operation firearms (semi-automatic and manual) in these cases determining solutions with the maximum simplicity and the minimum weight.  
     [0051] It is clear that numerous other variants can be brought to the loading device in question, without for this reason departing from the novelty principles inherent to the inventive idea, just as it is clear that, in the practical embodiment of the invention, the materials, the shapes and the sizes of the illustrated details can be whatever according to the requirements and they can be replaced with others which are technically equivalent.