FIELD OF THE INVENTION
This invention relates to target rifles. More particularly this invention relates to fore stock or muzzle supporting bipods which stabilize target rifles during competition target shooting.
BACKGROUND OF THE INVENTION
During competition rifle target shooting the fore stock or muzzle of the rifle is often supported by an inverted “V” configured bipod, having left and right legs. During target shooting, the lower ends or feet of the bipod are often supported by the ground or by a flat table or bench surface. Where the target resides at an elevation equal to or above the elevation of the rifle, and where the rifle's bipod rests upon a table support surface, the aimed trajectory of the rifle's barrel is typically skewed at a slight upwardly sloping angle with respect to horizontal. Upon firing the rifle, the beachward recoil of the rifle is correspondingly skewed at a slight downwardly sloping angle. Where the table's surface is horizontal, such downwardly sloping direction of the recoil may result in mechanical interference between the bipod's legs and the table. Such downwardly directed recoil tends to drive and compress the bipod's legs and feet downwardly against the table's surface.
The rifle's recoil along the table surface may also produce forwardly or muzzlewardly directed frictional forces against the bipod's feet. Where the “table” which supports the bipod's feet constitutes a ground surface, such frictional forces may be significant, resulting from irregularities in the ground and plowing effects of the bipod's feet against the ground. Such frictional forces tend to create moments of torque exerted by the bipod's legs against the rifle's muzzle or fore stock. Where the bipod normally extends perpendicularly downward from the muzzle or fore stock, such forwardly directed frictional forces, and the leg torque resulting from the frictional forces, often produce a slightly angled forward flexion of the bipod's legs at the instant of the rifle recoil. Such forward bipod leg flexions may draw the rifle's muzzle downwardly and rearwardly following an arc about the points of contact of the bipod's feet with the table surface, such downward motion occurring simultaneously with the rifle's recoil.
Such rifle recoil induced bipod leg compression and leg torsion actions constitute forces applied by the rifle to the bipod's legs which may undesireably deflect the rifle's muzzle away from the muzzle's precisely aimed trajectory. In many cases, such recoil induced muzzle deflections occur prior to the bullet's exit from the muzzle, undesirably perturbing the bullet away from its precisely aimed trajectory.
The instant inventive rifle bipod feet solve or ameliorate such undesirable aim disrupting recoil effects by incorporating into the feet of a rifle's bipod specialized components which are movable in relation to each other for the elimination of or minimization of muzzle oscillations and perturbations.
BRIEF SUMMARY OF THE INVENTION
First structural components of the instant inventive rifle bipod feet comprise left and right table contact members. In suitable embodiments, the left and right table contact members may comprise slide bars, slide shafts, roller bars, or roller shafts. Alternatively, the table contact members may comprise slide sleeves. The invention's table contact members necessarily have muzzleward and breechward ends, and have longitudinal axes extending between said ends. In the preferred embodiment, the table contact members are arranged so that their longitudinal axes are substantially parallel to the barrel of a rifle which is supported by the bipod.
Further structural components of the instant inventive rifle bipod feet comprise left and right bipod leg support members in combination with movable mounting means which interconnect the leg support members and the left and right table contact members. In the preferred embodiment, the invention's movable mounting means are adapted for, upon translations of the rifle's recoil from the bipod's left and right legs to the left and right leg support members, permitting longitudinal movements of the left and right leg support members toward the breechward ends of the table contact members. In the preferred embodiment, the surfaces which facilitate such longitudinal movements constitute low friction contacts.
In a suitable embodiment the invention's movable mounting means may comprise roller bearings or ball bearings in combination with roller or ball bearing guiding races formed within the table contact and leg support members. Alternatively, the movable mounting means may comprise a slidable quill and stem combination. For example, the quills of such combinations may comprise the invention's table contact members while the stems of such combinations may comprise the leg support members.
In a preferred embodiment, the table contact members further comprise left and right shoes which are fixedly attached to and extend downwardly from lower and preferably muzzleward ends of the left and right table contact members. The table contact members' shoe components may suitably comprise frictional pads or lugs. Alternatively, the shoe components may comprise pointed spikes or cleats.
Upon firing a rifle equipped with a bipod having feet configured in accordance with the instant invention, the rifle's recoil may drive the bipod's left and right legs and their attached left and right leg support members toward the breechward ends of the table contact members. Where the rifle is aimed at an upward trajectory, the longitudinal axes of the table contact members are oriented at a matching angle, causing the recoil to be directed longitudinally along the longitudinal axes of the left and right table contact members. The parallel motions of the rifle and the leg support members along the upwardly angled table contact members allow the recoil induced downward compression to be continuously experienced by the legs during their breechward passages along the table contact members. By dissipating or distributing the leg compressing impulse of the recoil over the time of passage of the leg support members from the muzzleward ends of the table support members to such members' breechward ends, the instantaneous vertical compression forces experienced by the bipod legs and feet are reduced. Such reduction of instantaneous leg compression forces advantageously reduces vertical oscillations of the rifle's muzzle during the rifle's recoil.
The interface between the leg support members and the table contact members is preferably smooth to facilitate low levels of sliding friction. By reducing sliding friction at the bipod's feet, the instant invention minimizes torque moments that are exerted by the bipod's legs against the rifle's muzzle or fore stock at the instant of the recoil. Such reduction of torque moments minimizes forward flexions of the bipod's legs at the instant of recoil, further reduceing oscillations and perturbations of the rifle's muzzle at firing.
Accordingly, objects of the instant invention include the provision of feet for a rifle bipod which incorporate structures as described above, and which arrange those structures in relation to each other in the manners described above for the performance of beneficial functions as described above.
Other and further objects, benefits, and advantages of the instant invention will become known to those skilled in the art upon review of the detailed description which follows, and upon review of the appended drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram showing a prior art right bipod leg and shoe or conventional foot, resting upon a table surface.
FIG. 2 is a perspective view of a suitable embodiment of the instant invention's right bipod foot, such foot mirroring a left bipod foot (not in view).
FIG. 3 is a sectional view of the FIG. 2 structure as indicated in FIG. 2.
FIG. 4 presents an alternate configuration of the structure of FIG. 3.
FIG. 5 shows mirroring left and right bipod feet, the view representationally showing left and right bipod legs supporting a rifle.
FIG. 6 is a side view of the structure of FIG. 2.
FIG. 7 re-depicts the structure of FIG. 6, the view of FIG. 7 showing bipod leg and leg support members driven breechwardly by a rifle's recoil.
FIG. 8 shows an alternate configuration of the instant inventive rifle bipod foot.
FIG. 9 is a sectional view of the FIG. 8 structure, the sectional plane coinciding with the page.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and in particular to FIG. 1, a right leg 2R of a rifle bipod is shown in dashed lines. The lower end of such rifle bipod leg 2R is equipped with a shoe or conventional bipod foot 4, such foot being attached to the lower end of the leg 2R by a screw 6. The lower end or surface of the shoe 4 rests upon and is supported by a substantially horizontal table for bench top 8. Such table surface or bench top 8 is intended as being representative of other rifle bipod supporting surface such as the ground. Hereinafter, references to table structures are intended to include all surfaces such as the ground, bench tops, wall parapets, and the like which may suitably be used for support of bipod feet during rifle firing.
In the prior art example of FIG. 1, an aim line 9 of a target rifle (not depicted within view) which is supported by the right bipod leg 2R (the left leg also not being within view) is canted slightly upwardly at an angle “a” with respect to the top of table 8. Upon firing the rifle, portions of the rifle's recoil are translated by the bipod leg 2R and by the attached shoe 4 to the table 8. The force of the recoil has orthogonal vector components Vrh and Vrv, the substantially horizontal force vector Vhr being angled slightly downwardly with respect to the horizontal tabletop 8 at the same angle “a” as the aim line 9. The substantially vertical recoil force vector Vrv is perpendicularly directed at an angle 90°—a, and an equal and opposite force Vct is exerted by tabletop 8 against the lower surface of the shoe 4. Such Vct force is simultaneously met and opposed by an equal and opposite force Vcr exerted by the rifle against the upper end of the bipod leg 2R.
The opposing force components Vcr and Vct are experienced within the bipod leg 2R substantially instantaneously with the recoil, resulting in compression of the bipod leg 2R along its vertical length. Such leg compression may produce a downward oscillation of the rifle's muzzle at the instant of the rifle's recoil. Such downward oscillation often occurs prior to the exit of the bullet from the rifle's muzzle, undesirably altering or skewing a precisely aimed trajectory of the bullet. A rebound or rarefaction of the bipod leg 2R often occurs immediately after the compression, further oscillating and skewing the aimed trajectory of the bullet.
Frictional contact between the lower end of the shoe 4 and the table 8 may simultaneously to rotate or pivotally move the leg 2R clockwise (according to the view of FIG. 1) about its upper connection with the rifle muzzle or fore stock, such rotation constituting a forward flexion of the bipod's legs. Where the table 8 constitutes a ground surface, and where the shoe 4 is alternatively configured to include a ground contacting spike or cleat, such recoil induced frictional contact may be markedly increased. Torsion forces resulting from such frictional shoe contact tend to further skew or perturb the precisely aimed orientation of the rifle's muzzle at and including the instant or the bullet's exit from the muzzle.
To ameliorate or lessen such recoil induced rifle muzzle oscillations and perturbations, the instant invention provides, referring further to FIG. 5, left and right rifle bipod feet 10L and 10R, such feet preferably being mirroringly identical to each other or having left to right symmetry. The right bipod foot 10R shown in FIG. 2 comprises a table contact member 20 having a lower end according to the view of FIG. 2, having a breechward end 21b facing the viewer, and having a opposite muzzleward end 21m. The table contact member 20, as depicted in the example of FIG. 2, includes left and right ball bearing or roller bearing receiving races 22 and 24, a breechward travel stop 28, and a muzzleward travel stop 26. Referring further to FIG. 3, the lower end of the table contact member 20 presents a shoe component 4A, such component being attached by means of a downwardly opening helically threaded socket 30 and mounting screw 6A combination.
In the FIGS. 2 and 3 configurations, leg support members 12 are provided, such members suitably forming a downwardly opening “C” channels. The open channels 14 of the leg support members 12 suitably presents left and right longitudinally extending bearing races 16 and 18 which are adapted to receive right and left longitudinally extending series of ball bearings 23 and 25. Such bearing series 23 and 25 are intended as being representative of other types of rollable bearings such as cylindrical roller bearings (not depicted within views).
Movable mounting means such as the ball bearing series 23 and 25 are provided, such means attaching the “C” channel configured leg support members 12 to the table contact members 20. Referring further simultaneously to FIG. 4, structures in FIG. 4 which are identified by a reference numeral having a suffix “B” are configured substantially identically with similarly numbered structures appearing in FIG. 3. In the FIG. 4 structural alternative alternatively configured downwardly opening “C” channel leg support members 13 form open channels 17 whose right and left walls present slide channels 15 and 11. As an alternative to the ball bearing configured movable mounting means of FIG. 4, the movable mounting means of FIG. 5 include right and left slide ridges 27R and 27L which are respectively nestingly received within the slide channels 15 and 11. The table contact members' shoe components, 4 or 4A, may comprise synthetic rubber knobs or lugs. Alternatively, such shoe components may be configured as plates, pointed spikes, or arrays of cleats (not depicted within views).
Referring simultaneously to FIGS. 2, 3 and 5, right and left leg attachment connectors or adaptors 32 are preferably provided, such connectors securely interconnecting the lower ends of bipod legs 3R and 3L with the right and left leg support members 12 of the right and left feet 10R and 10L. Such connectors 32 suitably present upwardly angled “C” channels 40 which are bounded and formed by webs or floors 39 which span between proximal ends of arms 36 and 38. The upwardly and rightwardly opening throats or channels 40 of the “C” channels of the left and right feet 10L and 10R are suitably closely fitted for receipts of the lower ends of the left and right bipod legs 3R and 3R. Inwardly facing walls of the “C” channels' arms 36 and 38 may advantageously bias against outer wall surfaces of such legs to prevent rotation of the feet with respect to the legs. Where the bipod legs have circular cylindrical extreme lower ends, the webs 39 of such “C” channel configured connectors may include a cylindrical walls 42 which are fitted for nesting receipts of such leg ends. Where the lower ends of such bipod legs present downwardly opening helically threaded sockets, the “C” channels' webs 39 may further include screw receiving apertures 45 which receive screw and washer combinations 44 and 43. Such screw and washer combinations may securely hold the bipod legs 3L and 3R within their “C” channel configured connectors 32.
In the configuration of FIGS. 2, 3, and 5, the connectors or adaptors 32 which attach the lower ends of the bipod legs 3L and 3R to the leg support members 12 of the feet 10L and 10R are securely mounted by means of nut and bolt fasteners 46. Return springs 48 span between spring mounts 50 at the muzzleward ends 21m of the table contact members 20 and the leg support members' mounting bolts 46, such springs normally biasing and returning the leg support members 12 to the muzzleward ends 21m of their table support members 20. In a preferred embodiment, the return springs are light force springs whose pulling forces are limited to ½ lbs. at two inches of extension. Such limited force springs are preferably capable of normally positioning the leg support members at the muzzleward ends of the table contact members 20 while translating only negligible portions of the rifle's recoil to the table contact members.
The muzzleward stops 26, which are attached to and extend upwardly from the upper and muzzleward ends of the table contact members, are preferably provided to limit muzzleward movements of the leg support members 12, and the breechward stops 28 correspondingly resist breechward movements of the leg support members 12 beyond the table contact members' breechward ends 21b.
Referring to FIGS. 8 and 9, alternate embodiments of the table contact member and leg support member components of the instant invention are depicted. In the FIGS. 8 and 9 structural alternative, each of the left and right table support members comprises a cylindrical sleeve 74 which slidably receives a cylindrical leg support member 72. Accordingly, the alternatively configured bipod feet of FIGS. 8 and 9 incorporate sliding quill and stem combinations.
In the FIGS. 8 and 9 alternate configuration, an internal springs 88 normally bias the leg support members 72 muzzlewardly, and muzzleward motions of the leg support members 72 are suitably stopped by muzzleward walls 80 of inwardly opening and horizontally extending pin travel channels 78. Latch pins 94 overlie biasing springs 92 which are slidably mounted within a radially extending pin channels 90, such pins 94 being normally positioned radially outwardly with respect to the cylindrical leg support members 72. Release channels 82 may be provided to allow the pins 94 to be driven radially inwardly to effect a muzzleward releases of the leg support members 72 from the table contact members' channels or bores 76. Helically threaded end caps 84 mounted upon helical threads 86 formed at the breechward ends of the table contact members 74 allow the springs 88 to be muzzlewardly installed and breechwardly extracted from the table contact members' hollow bores 76.
Connectors or adaptors represented by dashed line box 70 are provided. Such dashed lined boxes are intended as being representative of “C” channel connectors such as connector 32 shown in FIG. 2, along with other commonly known fasteners such as screw fasteners, snap fasteners, welded joints, adhesively bonded joints, and wholly formed joints. The adaptors 70 attach rifle bipod legs 2RB to the leg support members 72.
Shoes 96, which are suitably configured similarly with the shoe 4A of the FIG. 2 alternative, may be fixedly attached to and may extend downwardly from the lower ends of the table contact members 74 for direct contact with and support by the tabletop 8.
In operation of the instant invention, referring simultaneously to FIGS. 5 and 6, the left and right bipod feet 10L and 10R may be placed upon a tabletop, benchtop, or ground surface 8, with the shoe components 4A of the table contact members 20 directly resting against such table's upper surface. A rifle 64 supported by left and right bipod legs 3L and 3R may be aimed at an upwardly skewed trajectory represented by an acute angle “a” as shown in FIG. 6. The vertical trajectory angle of the rifle 64 preferably matches said angle “a” of the table contact member 20 and, correspondingly, the bipod legs 3L and 3R extend orthogonally at an angle 90°—a with respect to the table 8.
Upon firing the rifle 64, the recoil may move the leg support members 12 of the bipod feet 10L and 10R from their muzzleward positions as depicted in FIG. 6 to the breechwardly removed positions depicted in FIG. 7. During the breechward motions of the leg support members 12 from their muzzleward positions to their breechward positions, downwardly directed compression forces which are induced by the recoil are reduced, advantageously reducing vertical oscillations of the rifle's muzzle. Upon completion of the breechward recoil strokes of the instant inventive bipod feet, return springs 48 oppositely return the leg support members 12 to their muzzleward positions, readying the inventive bipod feet for a next rifle shot.
Referring simultaneously to FIGS. 1, 6, and 7, the rifle recoil which has driven leg support member 12 along table contact member 20 from the muzzleward position of FIG. 6 to the relatively breechward position of FIG. 7 would, if applied to the bipod leg 2R and foot/shoe 4 of FIG. 1, similarly frictionally and slidably move that foot/shoe 4 breechwardly along the table surface 8. Such frictional forces applied by the table 8 to the foot/shoe 4 during the rifle's recoil may rotate, pivot or forwardly flex the leg 2R clockwise about the leg's upper attachment to the rifle's muzzle or fore stock. Such leg rotations constitute applications of torque to the muzzle or fore stock which may undesirably perturb or disrupt the aim of the rifle's barrel. Reductions of sliding friction between the leg support members 12 and the table contact members 20 reduce or minimize torsion forces or torque translated by the bipod legs to the rifle's fore stock or muzzle, advantageously assisting in the maintenance of the marksman's aim during the rifle's recoil, including the instant of the bullet's exit from the muzzle.
Where the marksman's aim of the rifle is achieved and visually verified by an on-target position of the reticule or cross hairs of the rifle's optical targeting scope, and where the rifle's recoil moves the reticule away from the on-target position, the observed reticule movement may be correctly attributed to oscillations and perturbations emanating from the above-described bipod leg compression and torsion effects. Upon installation and use of the inventive bipod feet, the marksman may advantageously visually verify the rifle muzzle oscillation and perturbation reducing performance of the invention by observing a continuation of the on-target position of the rifle scope's reticule. In performance of its rifle muzzle oscillation and perturbation reducing function, the instant invention advantageously causes the rifle scope's reticule to remain on target from the trigger pull through the rifle's recoil, such continuity of reticule position corresponding with continuity of the aimed position of the rifle's muzzle both during and immediately subsequent to the bullet's exit from the muzzle.
While the principles of the invention have been made clear in the above illustrative embodiment, those skilled in the art may make modifications to the structure, arrangement, portions and components of the invention without departing from those principles. Accordingly, it is intended that the description and drawings be interpreted as illustrative and not in the limiting sense, and that the invention be given a scope commensurate with the appended claims.
Patent Application
20250198720
