Stock for precision sport rifles, particularly for biathlon.
The butt design for precision sporting rifles addresses the challenge of wind-induced instability by incorporating an ovalized front volume with optimized dimensions, resulting in improved stability and accuracy during outdoor shooting.
Patent Information
- Application Number
- FR2022009507
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-09-20
- Publication Date
- 2025-03-28
- Estimated Expiration
- 2042-09-20
AI Technical Summary
Existing rifle designs struggle with stability and precision due to wind-induced lateral aerodynamic thrust, which causes unpredictable movements and loss of accuracy in outdoor shooting conditions, particularly in biathlon.
The design features a butt for precision sporting rifles with a front volume that has an ovalized side profile, reducing air resistance and turbulence. This is achieved by a length of at least 150 mm, a transverse section with a height/width ratio of less than or equal to 65%, and a succession of oval sections that gradually offset to the front, optimizing wind penetration and stability.
This solution significantly reduces the harmful effects of lateral air flows, enhancing the stability and precision of the rifle by minimizing wind-induced instability, thus improving shooting accuracy in biathlon and similar sports.
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Abstract
Description
Title of the invention: Stock for a precision sport shooting rifle, in particular for biathlon Technical field of the invention
[0001] The present invention relates to a stock for a precision sport shooting rifle, in particular for practicing biathlon or similar sports. Prior art
[0002] Certain recreational or sporting shooting activities, in particular rifle shooting competitions in the standing or prone position, such as biathlon, are very largely practiced outdoors. The rifle user is therefore subject not only to intrinsic physiological phenomena of tremors linked to the practice (heartbeat / intense breathing after an effort which is difficult to control and which affects the stability of the weapon), but is also dependent on external conditions, and in particular the wind.
[0003] If it is already complex to manage the stability of a rifle, and therefore the precision of aiming and then shooting, during strong gusts of wind, the problem of the stability of the rifle in conditions considered normal in recreational practice, and especially in competition, is a particularly difficult question to resolve.
[0004] Indeed, the stocks of outdoor shooting rifles must meet multiple requirements, in particular adjustment, mass and sensitivity to wind. In the case of biathlon, the side wind can create a lateral aerodynamic drag force (turbulence against and around the rifle), which induces a heterogeneous thrust on the stock and an unpredictable movement of the latter which therefore more or less significantly distorts the accuracy of the shot.
[0005] However, the practitioner may have difficulty compensating for these (micro) movements because it is impossible to predict in advance the strength and direction of the wind at the time of aiming and then shooting. The practitioner therefore has difficulty opposing in real time, with delicacy and precision, the thrust force induced by this wind, which causes a significant loss of shooting accuracy, which is highly detrimental in competition.
[0006] Since the rifle's holding points are located behind it, in contact with the shooter's body, the moment of aerodynamic forces is all the greater the further they are applied from the holding points, i.e. on the front of the rifle. A significant part of the surface subjected to the wind therefore comes from the stock.
[0007] At the same time it is necessary to have a system for adjusting the position of the hand restraint offering a maximum amplitude and a fixing system of the carrying harness during non-shooting phases (Nordic skiing part).
[0008] Optimizations have been patented previously, concerning other parts of the rifle and relating to adjustments as well as wind resistance. For example, we can cite the international patent application WO2014104922Al relating to an adaptive cradle allowing length and height adjustments to be made on the rear of the stock.
[0009] Patent DE202015002015U1 describes carrying straps with a reduction in the wind-resistant surface.
[0010] Patent FR2463380A1 relates to a possible approach allowing easy adjustment of the harness.
[0011] Finally, patent EP3705836A1 describes the adaptation of the rear of the stock to a specific user.
[0012] None of these inventions address the wind resistance created by the front of the stock, and the resulting constraints on the harness adjustment latitude and the mass of the stock.
[0013] Thus, no truly effective solution has been proposed to counteract the effects of wind on the stability of the rifle, so that practitioners must redouble their efforts to obtain the desired shooting precision in order to obtain good results. Presentation of the invention
[0014] The present invention aims to remedy these drawbacks with a completely innovative approach. More specifically, the invention proposes to reduce the lateral aerodynamic thrust caused by the wind on the stock while allowing a large amplitude of adjustment of the stock's hand rest.
[0015] To this end, according to a first aspect, the present invention relates to a stock for a precision sport shooting rifle, in particular for biathlon practice, comprising a first rear part extending up to approximately 80 mm from a front edge of a breech housing and extending into a second front part of oblong shape defined by a front volume having: - a length extending along a firing axis, - a transverse dimension, or width, substantially perpendicular to the length, and - a vertical dimension, or height, substantially perpendicular to the length and width, characterized in that: - said front volume is less than or equal to approximately 200 cm3, - the length is greater than or equal to approximately 150 mm, and - the front volume has an oval lateral profile limiting air resistance, including at least one cross-section perpendicular to the firing axis has an aspect ratio less than or equal to about 65%.
[0016] This solution thus makes it possible to provide the front part of the stock with an optimized lateral air penetration rate in order to reduce turbulence and therefore the instability that this can cause when aiming and shooting, thus guaranteeing better precision of use as required for biathlon practice.
[0017] The invention is implemented according to the embodiments and variants set out below, which are to be considered individually or in any technically effective combination.
[0018] Advantageously, the front volume has, along a section plane perpendicular to the firing axis, a laterally oval section on either side of said axis.
[0019] This shape reduces the rate of air penetration and thus reduces the harmful effects of lateral air flows against / around the stick (lateral thrust of air on the stick causing movements of greater or lesser amplitude creating random instability that is difficult for the practitioner to control).
[0020] Preferably, the front volume axially comprises a succession of oval-section projections of different heights so that said projections gradually become thinner up to the front end, the height / width ratio of a first portion being between approximately 60% and 65%, preferably close to 62.75%, and the height / width ratio of a second portion being between approximately 40% and 45%, preferably close to 43%.
[0021] This solution makes it possible to refine the performance of the stock in terms of wind penetration and stability by dividing its front part into several sections of different dimensions.
[0022] In particular, the height of the first portion is at most approximately 35 mm and the height of the second portion is at most 25 mm, for a common width of approximately 40 to 55 mm.
[0023] More specifically, the height of the first portion is approximately 30 mm and the height of the second portion is approximately 21 mm, for a common width of approximately 48.5 mm.
[0024] According to a preferred embodiment of the present invention, the front volume has a lateral surface, called the aerodynamic reference surface, less than or equal to approximately 50 cm2.
[0025] According to a particular embodiment of the present invention, the front volume locally has an axial upper groove adapted for the passage of a barrel inserted in whole or in part in said groove.
[0026] Similarly, the front volume locally has lateral and / or lower grooves adapted to receive rails
[0027] According to a complementary aspect, the lower groove receives a longitudinal rail positioned at an angle of approximately 0 to 10 degrees relative to the firing axis, preferably between approximately 6 and 10 degrees, so that the front end of the stock approaches the barrel.
[0028] According to a preferred characteristic, the front volume is less than or equal to approximately 180 cm3.
[0029] Advantageously, the length is greater than or equal to approximately 170 mm
[0030] The present invention also relates to a rifle for precision sport shooting, in particular for practicing biathlon, comprising at least one cheek rest, a barrel which can be equipped with a sighting system, a receptacle for external ammunition magazine(s), a breech housing, an engagement lever / trigger, and a stock as described previously. Brief description of the figures
[0031] Other advantages, aims and characteristics of the present invention emerge from the following description given, for explanatory and in no way limiting purposes, with reference to the appended drawings, in which:
[0032] [Fig-1] [Fig.l] is a perspective view of a sport shooting rifle, and more spec specifically biathlon, equipped with a stick in accordance with the present invention,
[0033] [Fig.2] [Fig.2] is a perspective view of a front part of the stock in its raw state,
[0034] [Fig.3] [Fig.3] is a similar to [Fig.2] in which the front part of the stock has an upper groove for the passage of a barrel,
[0035] [Fig.4] [Fig.4] is a right view of [Fig.3],
[0036] [Fig.5] [Fig.5] is a left view of [Fig.3],
[0037] [Fig.6] [Fig.6] is a view similar to [Fig.5] in which the front of the stock is equipped with a side rail,
[0038] [Fig.7] [Fig.7] is a bottom view of [Fig.3], and
[0039] [Fig.8] [Fig.8] is a view similar to [Fig.7] in which the front of the stock is equipped with a bottom rail. Description of the embodiments
[0040] [Fig. 1] represents a precision sport shooting rifle 10, for example for recreational biathlon or preferably in competition, equipped with a stock 100 in accordance with the present invention and represented in more detail in FIGS. 2 to 8.
[0041] This biathlon rifle 10 typically comprises, in a known manner, a rear butt plate 12, a handle 14, a pommel 16, a cheek rest 20, a barrel 30 extending along a firing axis XX' and provided with a sighting system 40 (divided into a first proximal part of the eyepiece type 40a positioned substantially at the rear end of a breech housing 60 and a second distal portion 40b positioned at the front end of the barrel 30), a receptacle 50 for external magazine(s) of 22 Long-Riffle ammunition, a breech housing 60, a trigger 70, a manual engagement lever 80, a hand rest 90 and a stock 100 more specifically the subject of the present invention and divided into a rear portion 110 extended axially by a front portion 120.
[0042] Prior to the description, it is useful to precisely define the concept of front of butt 100. By convention, it will be noted that this is the part 120 extending by a distance D of more than 80 mm from the front plane of the breech housing 60, as can be seen in [Fig. 1].
[0043] This stock 100 is preferably made of solid wood, and more particularly of a type which allows, due to the weight / volume ratio of the stock and of course its shape, to provide the shooter with: - excellent stability, and therefore optimal precision and reproducibility of the shot, - excellent mechanical resistance, and therefore little, if any, deformation when fired, - good resistance whatever the thermal / climatic conditions of use (-20°C to +40°C, humidity or dryness), - consistency / homogeneity of the transfer of Fonde into the fibers, thus helping to guarantee the desired precision when aiming and then shooting.
[0044] The stock 100 of the present invention is designed to combine minimal lateral drag (side wind resistance), limited mass, and a particularly large hand rest adjustment range to accommodate different users and / or uses.
[0045] As a reminder, the lateral drag force produced by the movement of a fluid (air for example) of speed v is proportional to the section perpendicular to the flow of said fluid and to a drag coefficient, and more precisely such that:
[0046] [Math 1] F = 1 / 2 (p.v2.S.cx)
[0047] Where p is the density of the fluid, v is its speed, S is the cross-sectional area perpendicular to the movement of the fluid and Cx is the drag coefficient.
[0048] The objective of the invention is to adapt the front of the rifle 10 in order to reduce the sectional area S, as well as the drag coefficient, while allowing for example a large amplitude of adjustment of the hand rest 90.
[0049] The drag coefficient Cx is in particular dependent on the shape of the object which is in the moving fluid flow. In particular an oval shape following a direction perpendicular to the axis of the gun makes it possible to significantly lower this drag coefficient compared to a shape of identical non-ovalized section. This effect is particularly implemented on aircraft wings for which the drag coefficient must be as low as possible. In the case of a rifle stock, the wind can blow from one side or the other (or even above / below) the stock 100. Thus, unlike an aircraft wing, it is therefore necessary to adopt a shape that is symmetrical with respect to the vertical median plane of the stock 100.
[0050] Ultimately, an optimal shape of stock 100 makes it possible to reduce the cross-section, to have an elongated shape in the direction parallel to the axis of the barrel (firing axis) and to have an oval shape in the plane perpendicular to the axis of the barrel. All of these constraints must be applied in such a way as to reduce the volume and therefore the mass of the front of the stock 100.
[0051] Under these conditions, and as indicated previously, the stock 100 thus has a first rear part 110 arranged close to the breech housing 60 and extending into a second front part 120 of oblong and oval shape defined by a front volume V having a length L extending along a firing axis XX' (or aiming axis), a transverse dimension 1, or width, substantially perpendicular to the length, and a vertical dimension h, or height, substantially perpendicular to the length L and to the width 1.
[0052] According to a particular characteristic of the present invention, and as illustrated by figures 2 to 8, the volume V of the front part 120 of the stock 100 is less than or equal to approximately 200 cm3, preferably less than or equal to 180 cm3. This gives this front part 120 a sufficient dimension to fulfill its various functions (grip, possibility of fixing rails - see later in the description), with an optimized weight and above all a very particular shape which can be described as aerodynamic, with a reduced S.Cx.
[0053] For this purpose, the length L of the front part 120 of the stock 100 is greater than or equal to approximately 150 mm, preferably greater than or equal to approximately 170 mm, and the front volume V has a lateral profile that is laterally ovalized on either side of the axis XX' along a section plane perpendicular to the longitudinal axis XX'.
[0054] A cross-section, perpendicular to the axis of elongation, has a height h / width 1 ratio less than or equal to approximately 65%.
[0055] According to a particularly optimized embodiment, the front part 120 of the stock 100 axially comprises a succession of oval-section projections of different heights, so that said projections gradually become thinner up to the front end 101. In particular, the front part 120 comprises a first rear projection 121 whose height hl / width 11 ratio is between approximately 60% and 65%, preferably close to 62.75%, and a second front projection 122 whose height h2 / width 12 ratio is between approximately 40% and 45%, preferably close to 43%.
[0056] The projections 121 and 122 are connected by a slope 123 making a gentle and continuous transition, with an evolving inclination (from steeper to less steep as one approaches the front section 122)
[0057] More precisely, as can be seen in [Fig.4], the height hl of the first rear projection 121 is at most approximately 35 mm and the height h2 of the second front projection 122 is at most 25 mm, for a common width 11 or 12 of approximately 40 to 55 mm.
[0058] Even more precisely, the height hl of the first rear projection 121 is approximately 30 mm and the height h2 of the second portion 122 is approximately 21 mm, for a common width 11 or 12 of approximately 48.5 mm.
[0059] According to the right and left views of figures 4 to 6, the front portion 120 of the stock 100 has a lateral surface S, called the aerodynamic reference surface, less than or equal to approximately 50 cm2, which makes it less sensitive to the wind thanks to its highly oval transverse profile around which the air flows can circulate while reducing the grooves and the turbulences.
[0060] As can be seen in [Fig. 3], the front portion 120 of the stock 100 also locally has an upper groove 125 extending along the firing axis XX' and adapted for the passage of the barrel 30, which is then inserted in whole or in part into said upper groove 125. Thus, the barrel 30 can be inserted over approximately half of its external diameter inside this upper groove 125.
[0061] As can be seen in [Fig.5] to 8, the front portion 120 of the stock 100 also locally has a left lateral groove 126 and a lower groove 127.
[0062] The left lateral groove 126 is adapted to receive a rail 128 for example screwed directly into the wood and used to fix a carrying harness (not shown).
[0063] The lower groove 127 is adapted to receive a longitudinal rail 130, for example screwed directly into the wood and positioned at an angle a of approximately 0 to 10 degrees relative to the firing axis XX', and preferably between approximately 6 and 10 degrees, so that the front end 101 of the stock 100 gradually approaches the barrel 30. This lower rail 130 is used to receive the manual stop 90 (also called a hand rest), for example in the form of a small upright cylindrical stud measuring approximately 2-3 cm in height which can slide and be locked in the lower rail 130. This stop allows the user to position, during the prone shooting phase, the area of his hand located between his thumb and index finger in order to have a good grip on the rifle and therefore better precision.
[0064] When using this rifle 10, the user grips the stock 100 with his right or left hand (depending on whether he is right-handed or left-handed - the complete design of the rifle is therefore potentially partially or completely inverted / symmetrized with respect to a vertical plane parallel to the firing axis XX').
[0065] If gusts of wind or even a sufficiently strong breeze occur during aiming / shooting, and if the air currents generated are likely to have a destabilizing effect on the user's grip on the rifle due to excessive lateral thrust being exerted on the stock 100, the very specific shape of the front part 120 thereof will reduce turbulence (friction of the air on the external surface of the front volume V) so as to greatly reduce the risks of instability.
[0066] The user will therefore be able to concentrate more easily and in better conditions on his aim and the triggering of the shot, without fear of being destabilized, which will significantly improve the precision of his shot.
[0067] The user will also be able to have several longitudinal adjustment positions for the hand rest stop 90 and the harness to carry his rifle on his shoulders.
[0068] It should be clearly understood that the detailed description of the subject of the Invention, given solely by way of illustration, does not constitute in any way a limitation, the technical equivalents also being included in the scope of the present invention.
[0069] Thus, the wood / species chosen could be replaced by a wood-based composite material, carbon fiber or a mixture of several materials (a matrix / core and an external coating). 3D printing can be considered in some of the cases mentioned above to reduce costs and produce large series.
[0070] The front of the stock may have more than two projections provided that the lateral aerodynamics are respected (ovalized transverse shape and height / width ratio within the values indicated).
Claims
Claims
1. Stock (100) for a precision sport shooting rifle (10), in particular for biathlon, comprising a first rear part (110) extending up to a distance (D) of approximately 80 mm from a front edge of a breech housing (60) and extending into a second front part (120) of oblong shape defined by a front volume (V) having: - a length (L) extending along a shooting axis (XX'), - a transverse dimension (1), or width, substantially perpendicular to the length (L), and - a vertical dimension (h), or height, substantially perpendicular to the length (L) and to the width (1), characterized in that: - said front volume (V) is less than or equal to approximately 200 cm3, - the length (L) is greater than or equal to approximately 150 mm,and - the front volume (V) has an oval lateral profile limiting air resistance of which at least one cross-section perpendicular to the firing axis (XX') has a height (h) / width (1) ratio less than or equal to approximately 65%.,
2. Stock (100) according to claim 1, characterized in that the front volume (V) has, along a section plane perpendicular to the firing axis (XX'), a laterally oval section on either side of said axis.
3. Stock (100) according to any one of the preceding claims, characterized in that the front volume (V) axially comprises a succession of projections (121, 122) with an oval section of different heights so that said projections (121, 122) gradually thin out to a front end (101) of said stock (100), the height (hl) / width (11) ratio of a first portion (121) being between approximately 60% and 65%, preferably close to 62.75%, and the height (h2) / width (12) ratio of a second portion (122) being between approximately 40% and 45%, preferably close to 43%.
4. Stock (100) according to claim 3, characterized in that the height (hl) of the first portion (121) is at most approximately 35 mm and the height (h2) of the second portion (122) is at most 25 mm, for a common width (1) of approximately 40 to 55 mm.
5. Stock (100) according to claim 4, characterized in that the height (hl) of the first portion (121) is approximately 30 mm and the height (h2) of the second portion (122) is approximately 21 mm, for a common width (1) of approximately 48.5 mm.
6. Stock (100) according to any one of the preceding claims, characterized in that the front volume (V) has a lateral surface (S), called aerodynamic reference surface, less than or equal to approximately 50 cm2.
7. Stock (100) according to any one of the preceding claims, characterized in that the front volume (V) locally has an axial upper groove (125) adapted for the passage of a barrel (30) inserted in whole or in part in said groove (125).
8. Stock (100) according to any one of the preceding claims, characterized in that the front volume (V) locally has a lateral (126) and / or lower (127) groove adapted to receive rails (128; 130).
9. Stock (100) according to claim 8, characterized in that the lower groove (127) receives a longitudinal rail (130) positioned at an angle of about 0 to 10 degrees relative to the firing axis (XX'), preferably between about 6 and 10 degrees, so that the front end (101) of the stock (100) approaches the barrel (30).
10. Stock (100) according to claim 9, characterized in that the longitudinal lower rail (130) receives a hand-stop (90) movable along the latter.
11. Stock (100) according to any one of the preceding claims, characterized in that the front volume (V) is less than or equal to approximately 180 cm3.
12. Stock (100) according to any one of the preceding claims, characterized in that the length (L) is greater than or equal to approximately 170 mm.
13. Rifle (10) for precision sport shooting, in particular for practicing biathlon, comprising at least one cheek rest (20), a barrel (30) which can be equipped with a sighting system (40), a receptacle (50) for external magazine(s) of ammunition, a breech housing (60), a trigger (70), a manual engagement lever (80), and a stock (100) according to any one of the preceding claims.