Method and apparatus for rapid mounting and dismounting of a firearm accessory

A firearm accessory mount includes a main part with a rail receiving portion extending in a first direction that can receive a firearm mount rail, and includes a holding part with a rail engaging portion. The holding part is movable relative to the main part so that the rail engaging portion moves approximately parallel to a second direction forming an angle to the first direction. An adjusting portion positionally adjusts the rail engaging portion with respect to the main part, approximately parallel to a third direction transverse to each of the first and second directions. A manually operable member is operatively coupled to the holding part so that the holding part is moved approximately parallel to the second direction in response to movement of the member.

FIELD OF THE INVENTION

This invention relates in general to accessories for firearms and, more particularly, to techniques for removably mounting a firearm accessory on a firearm.

BACKGROUND

In some situations, it is desirable to be able to mount an accessory on a firearm. The most common type of accessory is a sight or scope that can increase the accuracy with which a person can aim the firearm. The person views an intended target through the sight or scope in association with a reticle, often with a degree of magnification.

Accessories such as firearm sights are usually aftermarket devices that need to be mounted on the firearm after the manufacturer has made and shipped the firearm. Usually, it is the end user who selects and mounts the accessory on the firearm. In some circumstances, a person may want to be able to quickly switch from one accessory to another, for example from one sight to another sight. Therefore, it has become relatively standard for firearm manufacturers to provide an accessory mounting rail on the firearm. The rail is usually provided on the “receiver” of the firearm, or in other words the part of the firearm that carries the bolt.

One very common type of mounting rail is known in the industry as a Picatinny rail. Although the Picatinny rail is effectively an industry standard, the industry specification for the Picatinny rail is not particularly precise. For example, it includes a drawing that has some dimensional errors. As a result, Picatinny rails vary somewhat in dimension from manufacturer to manufacturer, and even among different versions of a Picatinny rail made by the same manufacturer.

Many firearm accessories such as sights and scopes are provided with mounting arrangements that are designed to cooperate with a Picatinny rail. While these existing mounting arrangements have been generally adequate for their intended purposes, they have not been satisfactory in all respects.

For example, some have one or more knobs that each need to be rotated through several 360° revolutions in order to couple or decouple the mounting arrangement to the rail. Devices of this type cannot be mounted to and dismounted from a rail as rapidly as is sometimes desirable.

A further consideration is that, due to the dimensional variations among different Picatinny rails, some mounting arrangements will tightly and securely grip some Picatinny rails, but cannot tightly and securely grip other Picatinny rails. In some cases, if a particular Picatinny rail happens to be on the large side, a user may have to press hard on a lever or other actuating member in order to get the clamping mechanism to properly lock onto the rail. The force exerted on the lever can sometimes cause the lever to break.

Still other mounting arrangements have a cam or other clamping part that, as it moves into a clamping position, rubs along the side of the Picatinny rail, thereby abrading the side of the rail. This can mar and/or burnish the rail, which in turn can reduce the ability of the rail to be tightly and securely gripped by the mounting arrangement.

DETAILED DESCRIPTION

FIG. 1is a diagrammatic bottom view of an apparatus that is a firearm accessory mount10embodying aspects of the present invention.FIG. 2is a diagrammatic sectional view taken along the section line2-2inFIG. 1. In the following discussion, words such as up, down, top, bottom, horizontal and vertical are used in relation to the normal operation orientation of the accessory mount10, but it will be understood that this is for convenience and is not to be considered limiting. The accessory mount10is used to removably mount a not-illustrated accessory on the mounting rail12(FIG. 2) of a not-illustrated firearm, such as a rifle. The most common type of accessory is an aftermarket sight or scope, or in other words a device that is used to increase the accuracy with which the firearm can be aimed at a target. However, the accessory mount10can be used not only for a sight or scope, but also for any of a variety of other accessories.

The rail12inFIG. 2is a conventional type of rail that is commonly known in the art as a “Picatinny” rail. Although the Picatinny rail is effectively an industry standard, the industry specification for the Picatinny rail is not particularly precise. For example, it includes a drawing that has some dimensional errors. As a result, Picatinny rails vary somewhat in dimension from manufacturer to manufacturer, and even among different versions of a Picatinny rail made by the same manufacturer. With reference toFIG. 2, the rail12is elongate in a horizontal direction perpendicular to the plane ofFIG. 2. This direction is indicated diagrammatically inFIG. 1by a broken line16. The rail12has opposite side edges13and14that extend parallel to each other and to the direction16. The side edges13and14each taper outwardly, and would end in a sharp corner or point, except that there is a chamfer or bevel surface extending along the outer end.

The accessory mount10has a main part or base21. The base21is also sometimes referred to as a cover.FIG. 3is a diagrammatic perspective bottom view of the main part21. In the disclosed embodiment, the main part21is made of aluminum or an aluminum alloy, but it could alternatively be made of any other suitable material. A groove-like channel23is provided in the bottom of the main part21. The channel23extends parallel to the direction16, and is open at each end. The channel23has a flat inner surface24, and two sides27and28. The side27has two surfaces that intersect approximately at a right angle, to define a V-shaped groove. As shown inFIG. 2, this groove can slidably receive the outwardly tapered edge13of the rail12. The other side of the channel23is defined by a surface28that is inclined at an angle of approximately 45° with respect to the inner surface24, and that can slidably engage a surface on the edge14of the rail12. Thus, the rail12can be received within the channel23, and the accessory mount10is capable of sliding movement along the rail12in directions parallel to the line16, until the accessory mount is securely clamped to the rail in a manner described later. With reference toFIGS. 1 and 3, a projection33is disposed within the channel23, and extends downwardly from the inner surface24. When the accessory mount10is securely clamped to the Picatinny rail12, the projection33can engage any of several not-illustrated recesses provided at spaced locations along the length of the rail12, in order to prevent sliding movement of the base21on the rail12.

The base21has a downwardly-facing flat surface38that extends horizontally outwardly from the lower edge of the side28of the channel23. A short distance outwardly from the side28, the base21has a threaded cylindrical opening36that extends vertically upwardly from the surface38. The opening36does not extend all the way through the base21. The base21also has in the surface38a shallow annular groove37that concentrically encircles the opening36, a short distance radially outwardly from the opening36.

At a location spaced further outwardly from the channel23, the base21has a further cylindrical opening40that extends vertically upwardly from the surface38, and that opens through the top of the base. The opening40has a lower portion41and an upper portion42. The lower portion41has a larger diameter than the upper portion42, thereby defining a downwardly-facing annular shoulder43within the opening40. The base21also has a tab47that projects horizontally outwardly from a location near the openings36and40. Two spaced and parallel ribs or guides48and49are disposed on opposite sides of and project downwardly from the surface38. The guides48and49each extend parallel to a horizontal direction52that is perpendicular to the horizontal direction16.

With reference toFIG. 2, the accessory mount10includes a sleevelike cylindrical bushing61.FIG. 4is a diagrammatic perspective bottom view of the bushing61. The bushing61has a sleevelike lower portion62and a sleevelike upper portion63. The lower portion62has inside and outside diameters that are respectively larger than the inside and outside diameters of the upper portion63. Thus, the bushing61has a downwardly facing annular shoulder64in its interior, and upwardly facing annular shoulder65on its exterior. In the disclosed embodiment, the bushing61is made of steel, but it could alternatively be made of any other suitable material. The bushing61fits snugly with a force fit in the opening40(FIGS. 2 and 3) of the base21.

With reference toFIG. 2, the accessory mount10includes a shaft71that can rotate about a vertical axis72.FIG. 5is a diagrammatic perspective bottom view of the shaft71. The shaft71has a lower cylindrical portion76, a middle cylindrical portion77, and an upper cylindrical portion78, all of which are concentric to the axis72. The middle portion77has a larger diameter than the upper portion78, and the lower portion76has a larger diameter than the middle portion77. The upper portion78has external threads. The upper part of the middle portion77has flat surfaces on opposite sides thereof, one of which is visible at81. Adjacent each flat surface is an upwardly facing shoulder, one of which is visible at82. The shaft71has a cylindrical eccentric portion83that projects downwardly from a bottom surface of the lower portion86. The eccentric portion83has an axis84that is parallel to but offset radially from the axis of rotation72of the shaft71. In the disclosed embodiment, the shaft71is made of steel, but it could alternatively be made of any other suitable material.

With reference toFIGS. 2 and 5, the shaft71extends through and is rotationally supported by the bushing61. The lower portion76of the shaft has a bottom surface that is approximately flush with a bottom surface of the bushing61, and with the surface38on the base21. The shoulders82on the shaft71are approximately flush with a top surface of the bushing61, and with an adjacent surface on the base21.

With reference toFIGS. 1 and 2, the accessory mount10includes a locking lever101.FIG. 6is a diagrammatic perspective top view of the locking lever101. In the disclosed embodiment, the locking lever101is made of steel, but it could alternatively be made of any other suitable material. The locking lever101has a disk-shaped portion102at one end, and an arm103extending outwardly from the disk-shaped portion102. The locking lever101is generally platelike, except that the outer end of arm103is thicker than the rest of lever101. The lever101has a flat top surface104. Near the outer end of the arm103, three spaced cylindrical openings106,107and108each extend downwardly from the top surface104into the thicker part of the arm103. The openings107and108each extend completely through the arm103. The opening106extends only partway through the arm103. The disk-shaped portion102has in the center thereof a slot111that extends vertically through the portion102.

With reference toFIGS. 2,5and6, the slot111in the lever101receives the upper part of the middle portion77of the shaft71. The flat surfaces81on opposite sides of the shaft71engage the flat surfaces on opposite sides of the slot111, so that the lever101is fixed against rotation with respect to the shaft71about the axis72. The disk-shaped end portion102of the lever101has a bottom surface that engages the upwardly-facing shoulders82on the shaft71, and that slidably engages a top surface of the bearing61. With reference toFIG. 2, a nut116engages the threaded upper portion78of the shaft71, in order to keep the locking lever101in position on the shaft71, and in order to keep the shaft71within the bushing61.

With reference toFIG. 1, a locking slide121is movably supported on the outer end of the arm103of the lever101.FIG. 7is a diagrammatic perspective top view of the locking slide121, andFIG. 8is a diagrammatic perspective bottom view of the locking slide121. In the disclosed embodiment, the locking slide121is made of aluminum or an aluminum alloy, but it could alternatively be made of any other suitable material. The locking slide121has a top surface122, and a bottom surface123. A recess126of approximately oval shape extends upwardly into the locking slide121from the bottom surface123. At one end of the locking slide121, the recess126opens laterally outwardly through a side wall of the slide, as indicated at127. Horizontal ribs128and129are provided on opposite sides of the recess126adjacent the bottom surface123, and each project inwardly a short distance. Each of the ribs128and129defines an upwardly facing shoulder, one of which is visible at131. At the end of the slide121opposite from the open end127of the recess126, a slot136extends vertically downwardly from the top surface122and opens into the recess126.

FIG. 9is a diagrammatic top view of the locking lever101, with the slide121movably supported thereon.FIG. 10is a diagrammatic sectional view taken along the section line10-10inFIG. 9. With reference toFIG. 10, an upper end of the recess126in the slide121is defined by a downwardly-facing top surface141. The top surface141has two spaced, shallow recesses142and143that each have the shape of a portion of a sphere. The thick outer end of the arm103on lever101extends into the recess126through the open end127, and is slidable within the recess126. The upwardly facing top surface104of the lever101slidably engages the downwardly facing top surface141in the recess126. A bottom surface146on the thick end of arm103slidably engages the upwardly facing shoulders131on each of the ribs128and129. A tubular slotted spring pin151is made of steel, and is snugly received with a force fit in the vertical opening108of the lever arm103. The upper end of the pin151extends beyond the top surface104of the lever, and is slidably received within the slot136in the slide121. The upper end of the pin151can engage opposite ends of the slot136in order to limit sliding movement of the slide121relative to the lever arm103.

A detent mechanism is disposed within the opening106in the lever arm103, and includes a metal coil spring161disposed in the lower portion of the opening106, and a steel ball bearing162disposed in the upper portion of the opening106. The spring161resiliently urges the ball bearing162upwardly. The slide121can move with respect to the arm103between a locking position and a release position in which the ball bearing162respectively engages the recesses142and143. As the slide121is moved from one position to the other, the ball bearing162is forced downwardly against the urging of the spring161as it leaves one recess, and then is moved back upwardly by the spring161when it reaches the other recess.

With reference toFIGS. 1 and 2, a threaded stud171has its upper end threadedly engaging the threaded opening36(FIGS. 2 and 3) in the base21. This end of the stud171is fixedly secured within the opening36by a commercially-available adhesive, such as a cyanoacrylate adhesive. In the disclosed embodiment the stud171is made of steel, but it could alternatively be made of any other suitable material.

Referring toFIGS. 1 and 2, the accessory mount10also includes a platelike locking blade173that, in the bottom view ofFIG. 1, has an approximately rectangular shape. In the disclosed embodiment the locking blade173is made of steel, but it could alternatively be made of any other suitable material. The locking blade173has two slots176and177that open vertically therethrough. The slot176extends approximately parallel to the direction52, and the slot177extends approximately parallel to the direction16. The locking blade173has an end surface178(FIG. 2) that is adjacent to the side28of the channel23in the base21, and that is inclined at approximately 90° with respect to the surface defining the side28of the channel. The surfaces28and178together define a V-shaped groove that can slidably receive the outwardly tapered edge14of the rail12.

The locking blade173has a top surface181that is slidably disposed against the downwardly facing surface38on the base21. The groove176in the locking blade173slidably receives the threaded stud171, and the groove177slidably receives the eccentric portion83of the shaft71. The locking blade173is disposed between the guides48and49on the base21, and each guide48and49slidably engages a respective side edge of the locking blade173.

A locking nut182is threadedly engaged with the outer end of the threaded stud171, and slidably engages the bottom surface of the locking blade173. With reference toFIG. 2, a multiwave compression spring186is disposed within the annular groove37, and slidably engages the top surface181of the locking blade173. In the disclosed embodiment, the multiwave compression spring is obtained commercially as part number MW0375-0150-04S from Associated Spring Raymond, Barnes® Group Inc., of Maumee, Ohio. However, it would alternately be possible to use some other type of spring arrangement.

The multiwave compression spring186resiliently urges the locking blade173downwardly away from the base21. Downward movement of the locking blade173under the urging of the spring186is limited by sliding engagement of the locking blade173with the locking nut182on the stud171. By rotating the locking nut182, the vertical position of the nut182on the stud171can be varied, and this in turn determines the vertical position of the end of locking blade173having the inclined end surface178. Thus, by turning the locking nut182, the surface178can be adjusted vertically with respect to the adjacent surface on base21that defines side28of the channel23.

A brief description of the operation of the accessory mount10will now be provided. With reference toFIGS. 1 and 2, the lever101can be manually pivoted about the vertical axis72, thereby rotating the attached shaft71about the axis72. In response to this rotational movement of the shaft71, the eccentric portion83of the shaft, through cooperation with the slot177in locking blade173, moves the locking blade173horizontally with respect to base21, parallel to the direction52. During this movement, the threaded stud171slides within the slot176.

If the lever101is pivoted counterclockwise inFIG. 1from the illustrated position through an angle less than 180°, the locking blade173is moved horizontally outwardly, or in other words downwardly inFIG. 1and rightwardly inFIG. 2. This moves the end surface178on the locking blade away from the channel23in the base21, so that the rail12can be inserted into or removed from the channel. Assume that the rail12is inserted into the channel23. The lever101is then pivoted clockwise inFIG. 1back to the position illustrated inFIG. 1. As this occurs, the locking blade173is moved inwardly, or in other words upwardly inFIG. 1and leftwardly inFIG. 2. This causes the end surface178on the locking blade to move to the position shown inFIGS. 1 and 2, where the rail12is retained within the channel23. The geometry of the mechanism is such that, as the lever101is pivoted clockwise, the manual force needed to move the lever decreases, even as the rail is being gripped more tightly. Also, the eccentric portion83moves through an over-center position in relation to the Locking blade173, such that the lever101, the shaft71and the locking blade173all tend to remain in their locking positions.

With reference toFIG. 1, when the lever101is in this locking position, the slide121is aligned with the tab47on the base21, and the slide121can be manually moved inwardly to its locking position, causing the tab47to be captured within the recess126in the slide. In this position of the slide121, the cooperation of the slide121with the tab47holds the arm101against pivotal movement. Of course, as discussed above, the eccentric portion83is in an over-center position in relation to the locking blade173, and thus the lever101would tend to remain in its locking position even without engagement of the slide121with the tab47. However, engagement of the slide121with tab47avoids inadvertent movement of the lever101away from its locking position, for example where the firearm is being carried and the lever101is accidentally bumped against a stationary object such as a door frame. Eventually, the slide121can be manually moved outwardly to the position shown inFIG. 1, thereby releasing the tab47from the slide, so that the lever101can again be manually pivoted.

With reference toFIG. 2, the spring186urges the locking blade173downwardly against the locking nut182. The locking nut182can be turned to adjust its vertical position on the stud171, thereby adjusting the vertical position of the end surface178of locking blade173with respect to the surface defining side28of channel23in base21. This permits the accessory mount10to be adjusted to readily accommodate dimensional variations from one Picatinny rail12to another. In particular, it ensures that the accessory mount10can be easily adjusted to securely grip any Picatinny rail12, without being too loose or too tight. By avoiding a situation where the grip is too tight, there is no risk that a manual force needed to move the lever101to its locking position would be so great that it might bend or even break the lever101. Since the locking blade173moves transversely with respect to the rail12, the end surface178thereon does not rub against and abrade the locking rail12as the locking blade moves to and from its locking position. Since the lever101pivots through an angle less than 360°, and in fact less than 180°, the disclosed locking mechanism is a quick-release arrangement that permits the accessory mount10to be rapidly mounted on or dismounted from the rail12.

Although a selected embodiment has been illustrated and described in detail, it should be understood that a variety of substitutions and alterations are possible without departing from the spirit and scope of the present invention, as defined by the claims that follow.