WO2007082990A1

WO2007082990A1 - Stock for a firearm

Info

Publication number: WO2007082990A1
Application number: PCT/FI2007/000016
Authority: WO
Inventors: Juha Aalto; Kari Kuparinen
Original assignee: Sako Oy
Priority date: 2006-01-17
Filing date: 2007-01-17
Publication date: 2007-07-26
Also published as: FI7074U1; EP1979702A1; EP1979702A4; US20100180484A1; FIU20060020U0

Abstract

A stock (10) for a firearm, provided with a stock frame section (3) and a releasably attachable cheekpiece (1, 2), in which the stock frame section (3) is symmetrical in relation to the longitudinal vertical direction of the stock, and when the cheekpiece (1, 2) is installed to the left side of the stock frame section (3), the stock becomes a right-handed stock, and when the cheekpiece (1, 2) is installed to the right side of the stock frame section (3), the stock becomes a left-handed stock. According to an advantageous embodiment the cheekpiece (1, 2) is adjustable, preferably quick- adjustable in height.

Description

Stock for a firearm

The present invention relates to a stock for a firearm, such as a rifle or shotgun, consisting of a stock frame and a releasably attachable cheekpiece.

The stock for a firearm is made either symmetrically to the longitudinal vertical plane of the stock so that the firearm is suitable both for right- and left-handed persons, or asymmetrically, in which case it is better suited for either a right-handed or a left-handed user. In most cases, right-handed users support the firearm against the right shoulder, i.e. they shoot from the right, in which case the user's right cheek is supported against the left side of the stock. Respectively, left-handed users mostly support the firearm against the left shoulder. Thus, an asymmetrical stock is called a right-handed stock, when the stock is designed to be supported against the right shoulder, and a left-handed stock, when the stock is designed to be supported against the left shoulder. If the stock is provided with a cheekpiece, the stock is usu- ally made either as a right- or left-handed version.

In this invention, the cheekpiece refers to an element at the rear part of the stock, which forms a planar surface or a surface with a large radius of curvature to the side of the stock between the grip and the recoil pad, in which case the cheekpiece can also be identified by a surface composed by a large radius of curvature, compared with the absolute value of an average radius of curvature for a contour of a transverse cross-section in relation to a longitudinal direction of the stock. The said planar surface or the surface with a large radius of curvature is arranged at an acute angle α opening downwards in relation to the longitudinal vertical section of the stock, the angle α being approximately 12 - 30°. The function of this cheekpiece is to expand the contact area between the user's cheek and the stock and thus to provide the user with a better touch to the stock and to reduce the recoil feeling caused by the firing of the firearm, which the user experiences in the cheek area.

The publication US 4055016 discloses a releasable stock brush, by means of which the height and shape of the brush can be fitted for the needs of the user.

The publication US 4122623 discloses an adjustable stock, by means of which the height of the stock brush can be adjusted to be suitable for the user.

The publication US Des. 300343 discloses a symmetrical releasable cheekpiece for a rifle stock. The object of the present invention is to achieve a new-type stock for a firearm, such as a rifle or shotgun, which can easily be adapted according to the needs of the user. It is also an object of the invention to offer a solution, which makes possible an easy and simple way to change the geometry of the stock. It is also an object to combine in a simple manner the advantages offered by an asymmetrical stock provided with a cheekpiece and those of a symmetrical stock without a cheekpiece. It is also one object of the invention to simplify the manufacture of the stock especially when the stock is made of a synthetic material, such as fibre-reinforced polymer.

The stock according to the present invention is characterised in that the frame sec- tion 3 of the stock is symmetrical in relation to the longitudinal vertical plane of the stock and, when the cheekpiece 1, 2 is installed to the left side of the stock frame section 3, the stock becomes a right-handed stock, and when the cheekpiece 1, 2 is installed to the right side of the stock frame section 3, the stock becomes a left- handed stock. In this case, the actual frame section of the stock can be symmetrical, and only the cheekpiece is installed to make the stock to be either right- or left- handed. Thus, several advantages are achieved both for the use of the firearm and for the manufacture of the firearm. In this way the stock frame section of the firearm, i.e. the basic structure can be made uniform, and the user-specific fitting can be easily made by means of a changeable cheekpiece. However, it has to be noted that the above-mentioned symmetry must not be interpreted too tightly, i.e. also a symmetrical stock may have some point, which deviate from the absolute symmetry. These points are connected to the construction of the firearm and they can be, for example, the lock cam and its required fitting to the stock, the unilateral need for space required by the firing device, or similar.

The cheekpiece can also have several different sizes and models. This facilitates, for example, the use of scope legs of different heights, because different scopes can be acquired for the same basic firearm for different purposes. For example, in some countries the number of firearms owned by one person has been restricted so that such an easy alteration in the stock geometry corresponding to such changing needs will reduce the need for separate firearms. For example, a scope sight with the outer diameter of 40 mm can be used when hunting in the daylight, which scope can be installed on low legs, in which case the shooting position can be made good and natural when using a medium-height cheekpiece. For stalking hunting in the twilight, a scope sight with the outer diameter of 62 mm can be used, which is attached to the firearm with higher scope legs, in which case the shooting position can again be made suitable when using a higher cheekpiece. Traditional iron sights, i.e. bead loop sights usually have the lowest lines of sight, in which case a low cheekpiece provides the best shooting position for most users.

Further, taking into consideration the personal features of the user's face is easier, when there are different cheekpieces to choose from, from which it is possible to choose for the user a cheekpiece which, in addition to a suitable height is, for example, provided with an appropriate angle α between the planar surface or the surface with a large radius of curvature of the cheekpiece and the longitudinal vertical angle of the stock. Also the user-specific design of this releasable cheekpiece is easy, and it does not have a decisive effect on the resale value of the firearm itself, because the valuable stock assembly or frame section need not be irreversibly redesigned. This is true especially with stocks made of valuable first-rate stock wood, such as root of a walnut tree. This is also true with a stock made of synthetic material, the geometry of which is relatively difficult to change to meet the wishes of the user without the appearance of the stock suffering significantly. By means of the inven- tion, also the appearance of the stock can naturally be maintained similar to the stock of a traditional hunting gun without the stock looking like an adjustable stock of a firearm used in a shooting range.

It is characteristic of an embodiment of the invention that the cheekpiece can be either right-handed for forming a right-handed stock or left-handed for forming a left- handed stock. A second embodiment of the invention is characterised in that the cheekpiece can be symmetrical in relation to a certain plane, in which case either a right- or left-handed stock can be formed by means of the same cheekpiece by altering the installation side.

The invention will next be explained by means of an example, referring to the en- closed drawings, in which

Figure 1 presents a stock for a firearm with a frame section and a cheekpiece;

Figure 2 represents the fastening system of the cheekpiece inside the stock;

Figure 3 presents a cheekpiece fastened to the frame section of the stock for making the stock left-handed; and

Figure 4 presents a cheekpiece fastened to the frame section of the stock for making the stock right-handed. Figure 1 discloses a right-handed stock 10, which has a cheekpiece 1 releasably attached to a frame section 3 of the stock, the cheekpiece thus being installed to the left side of the stock for making a right-handed stock. The stock is also provided with a grip 9 with a recoil pad 5. The longitudinal direction of the stock 10 is sub- stantially the same as the direction of the barrel of the firearm, and the vertical direction of the longitudinal vertical plane of the stock is illustrated by dot-and-dash lines in Figures 3 and 4. Figures 3 and 4 illustrate a transverse cross-section in relation to the longitudinal direction of the stock at the cheekpiece seen from the back, i.e. from the direction of the user. Figure 3 illustrates a left-handed stock according to the invention, in which the cheekpiece 2 is installed to the right from the stock frame section 3, i.e. to the right side. It also discloses the acute angle α opening downwards between the planar surface or surface with a large radius of curvature forming the cheekpiece and the longitudinal vertical plane of the stock. Figure 4 illustrates a right-handed stock according to the invention, in which the cheekpiece 1 is installed to the left side of the stock frame section 3.

One embodiment of the invention is characterised in that the cheekpiece can be attached by a hook-like attaching part inside the stock so that the part can be locked in place by the fastening screws of the recoil pad. A second embodiment of the invention is characterised in that the lower section of the attaching part can be locked to the stock by the fastening screw of the carrying strap for the firearm. One option for realising these embodiments is shown in Figure 2.

Figure 2 illustrates one possible embodiment for fastening the cheekpiece to the stock frame section 3, especially adapted to a case, in which the stock frame section 3 and the cheekpiece 1 are made of synthetic material, such as fibre-reinforced polymer. The cheekpiece 1, 2 can be fastened by the attaching part 4 inside the stock frame section 3 so that the attaching part can be locked in place by the fastening screws 6 of the recoil pad 5. The attaching part 4 can, for example, be hook- shaped and/or wedge-shaped so that tightening the fastening screws 6 of the recoil pad 5 locks the cheekpiece 1, 2 tightly to the stock frame section 3. The lower sec- tion 7 of the attaching part 4 can be locked to the stock frame section 3 by the fastening screw 8 of the carrying strap 8 ofor the firearm. In the embodiment according to the Figure, the parts 1, 2, 3 and 4 are thus all made of synthetic material, such as plastic or polymer. For suppressing the recoil feeling, the recoil pad 5 is made of soft rubber or elastomer. Cheekpieces can also be made in different heights and shapes, even though the Figures only illustrate cheekpieces of one height. One possible embodiment of the invention is further to arrange the cheekpiece 1, 2 to be adjustable in height, preferably quick-adjustable, in which case the user can alter the geometry of the stock according to a momentary need. Such an adjustment option is useful, for example, in situations in which the user uses the firearm in a Iy- ing position instead of the upright position he more often uses. The quick adjustment makes possible the immediate adaptation of the stock 10 for the firearm to correspond to the altered shooting position. One desirable feature in such a quick adjustment is the lockability so that the cheekpiece will stay firmly in place and will not move in its attachments with a play. In connection with this invention, the quick adjustability refers to the option to change the place of the cheekpiece without tools.

The features providing the cheekpiece 1 quick-adjustable in height together with the above-mentioned features providing the reversibility of the cheekpiece make possible a specially convenient embodiment especially for firearms for common use. The stock for the firearm can be made uniform, but the users can easily adjust them to be right- or left-handed and even make the height of the cheekpiece ergonomically optimal for a momentary situation of use.

One factor affecting the user convenience of the cheekpiece, in addition to issues relating to geometry, is the feel against the user's cheek. Factors having an influence on this are the hardness of the cheekpiece, the friction coefficient between the cheek and the cheekpiece, and the thermal conductivity of the cheekpiece. These material parametres can be adapted according to the principal range of use of the stock or the user's habits. For example for cold areas, the thermal conductivity is significant in the situation of use. In such a case the material for the cheekpiece can be selected so that the thermal conductivity of the material is as poor as possible so that the cheek- piece will feel warm against the cheek even in cold air. Further, considering the warm areas of the globe it may be pleasant that the cheekpiece would have a relatively high thermal conductivity so that the cheekpiece will feel cool against the cheek. This effect can be achieved, for example, so that the material for the cheekpiece 1, 2 is selected with its thermal conductivity being lower or higher than the thermal conductivity of the stock frame section 3.

Further, the hardness of the cheekpiece can be selected according to the embodiment; for example, for firearms with a strong recoil the cheekpiece can be made of soft material, such as gel-like rubber or other similar elastomer. In this case, the cheekpiece is thus at least partly made of gel-like material. Likewise, the friction coefficient can be adapted to correspond to a typical situation of use. It can be assumed that the majority of the users of the firearm would think that too high a fric- tion coefficient feels unpleasant when using the firearm, as the skin "sticks" to the cheekpiece and that too low a friction coefficient again makes difficult to find a stable shooting position, if the cheek feels slippery against the cheekpiece.

Claims

1. A stock (10) for a firearm, provided with a stock frame section (3) and a re- leasably attachable cheekpiece (1, 2), characterised in that the stock frame section (3) is symmetrical to the longitudinal vertical plane of the stock and, when the cheekpiece (1, 2) is mounted to the left side of the stock frame section (3), the stock becomes a right-handed stock, and when the cheekpiece (1, 2) is mounted to the right side of the stock frame section (3), the stock becomes a left-handed stock.

2. A stock (10) for a firearm according to claim 1, characterised in that the cheekpiece (1, 2) can be fastened by a hook-like attaching part (4) inside the stock (3) so that the attaching part can be locked in place by the fastening screws (6) of the recoil pad (5).

3. A stock (10) for a firearm according to claim 1 or 2, characterised in that the lower part (7) of the attaching part (4) can be locked to the stock (3) by the fastening screw (8) of the carrying strap for the firearm.

4. A stock (10) for a firearm according to claim 1, characterised in that the cheekpiece can be symmetrical to an axis, in which case either a right- or left- handed stock can be formed by means of the same cheekpiece by changing the mounting side.

5. A stock (10) for a firearm according to claim 1, characterised in that the cheekpiece (1, 2) is adjustable, preferably quick-adjustable in height.

6. A stock (10) for a firearm according to claim 1, characterised in that the material for the cheekpiece (1, 2) is softer than the material for the stock frame section (3).

7. A stock (10) for a firearm according to claim 1, characterised in that the cheekpiece (I₅ 2) is at least partly made of a gel-like material or other elastomer.

8. A stock (10) for a firearm according to claim 1, characterised in that the thermal conductivity of the cheekpiece (1, 2) is lower than that of the material for the stock frame section (3).

9. A stock (10) for a firearm according to claim 1, characterised in that the thermal conductivity of the cheekpiece (1, 2) is higher than that of the material for the stock frame section (3).