Mount for attaching a device to a firearm
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. Ser. No. 06/520,893, now U.S. Pat. No. 4,494,328 filed Aug. 8, 1983, and entitled &#34;MOUNT FOR ATTACHING A DEVICE TO A FIREARM&#34;. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention relates to weapons, such as firearms which are laser aimed, and more specifically relates to a mount for attaching a device, such as a laser gunsight, to a weapon. 
     Laser aiming devices for firearms are well known. Examples of such devices are disclosed in U.S. Pat. Nos. 4,152,754; 4,233,770; 4,313,272; and 4,313,273. In each of the devices disclosed in these patents, it is important that the laser beam emitting device be properly mounted to the firearm in order to obtain accurate aiming. The mounts for the lasers shown in these patents cannot readily be attached and removed from the weapon. It would be advantageous, however, to have a mount which can quickly be attached and detached from the weapon for immediate interchange for use on another weapon or for storage when not in use. 
     Other considerations are important in providing a means for quickly mounting and detaching a laser gunsight from a weapon. For example, since the combined weight of the weapon and its ammunition becomes critical in combat situations where maneuverability in the field is essential, it is important that any mounting means be lightweight. Further, in order to provide economy and convenience, it would be advantageous to provide a mount which requires no modification to the weapon. Such a mount should also provide adjustment for windage and elevation, and should not be subject to even slight wobble or side-to-side movements once mounted on the firearm, enabling the laser gunsight to be removed from the weapon and remounted and still remain properly aligned. Further, there should be no interference with the conventional sights of the weapon, thereby allowing the user an instant choice as to which aiming method is used. 
     Accordingly, in U.S. patent application Ser. No. 500,417 filed June 2, 1983, now U.S. Pat. No. 4,539,769 owned by the same assignee as the present application, a mount for attaching a device to a firearm is disclosed which comprises a longitudinal base adapted to carry the device to be mounted and having a track extending along the portion of the length thereof. A block is slidably mounted in the track, and spring means is provided for biasing the block toward one end of the base. First means is mounted to the block and adapted to be attached to a first fixed member at one end of a firearm barrel. Second means is provided for attaching the other end of the base to a second fixed member at the other end of the firearm barrel. 
     The device is mounted by attaching the first means to the first fixed member, sliding the base forward relative to the block until the second means is in a position to be attached to the second fixed member, aligning the second means with the second fixed member, and releasing the mount to cause the base to slide rearward with respect to the block in response to the biasing action of the spring means, thereby engaging the second means with the second fixed member. 
     In U.S. patent application Ser. No. 520,893, now U.S. Pat. No. 4,494,328 filed Aug. 8, 1983 in the name of Frederick G. Stevens and also assigned to the same assignee as the present invention, a U-shaped anti-wobble spring is also provided above the second means to grasp and surround the second fixed member on the firearm to substantially preclude side to side or lateral movement of the mount. In this invention, means in the nature of a clamping thumbscrew is provided for contact with the U-shaped anti-wobble spring to assure that it securely locks to the second fixed member on the firearm to preclude even the slightest side to side or lateral movement of the mount relative to the firearm, which may result in improper orientation of the gunsight. 
     As in the prior application, means are provided for windage and elevation adjustment on the mount; and the second means can comprise a second block containing a notch adapted for mating engagement with a portion of the second fixed member, which may, for example, be a bayonet holder fixed to the firearm. A single pivoting lever arm with a tab extending into the notch can be provided, with means for spring loading the tab in the notch to lock the second means onto the second fixed member. The U-shaped anti-wobble spring is mounted in the block above the lever arm to surround and grasp the bayonet holder once the tab extends into the notch to lock the second means onto the second fixed member or bayonet holder. The thumbscrew can then be tightened to assure complete rigidity between the bayonet holder and mount. 
     The mount is particularly suited for mounting a laser gunsight to a conventional weapon. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein: 
     FIG. 1 is a perspective view showing a laser gunsight mounted to a weapon using the mount of the present invention; 
     FIG. 2 is a side view of the gunsight as it is being mounted to the weapon; 
     FIG. 3 is a side view of the mounted gunsight; 
     FIG. 4 is an exploded perspective view of the mount of the present invention; 
     FIG. 5 is a top view of the mount of the present invention; 
     FIG. 6 is a sectional view taken substantially along line 6--6 of FIG. 5; 
     FIG. 7 is a sectional view taken substantially along line 7--7 of FIG. 6; 
     FIG. 8 is a bottom exploded perspective view of the second block of the mount of the present invention; 
     FIG. 9 is an exploded perspective view of an alternative form of a portion of the mount of FIG. 4; and 
     FIG. 10 is a view similar to FIG. 7, but illustrating the use of the alternative mount of FIG. 9. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in FIG. 1, a laser gunsight generally designated 10 is mounted to weapon 14 using the mount of the present invention. Laser gunsight 10 includes a laser which emits a beam from opening 12 and includes a self-contained power source, such as batteries. 
     A first means, shown in this embodiment as an open collar 30, encircles one end of the barrel 20 and abuts the rear of a first fixed member, shown in this embodiment as a flash suppressor 18, of weapon 14. A second means, shown as a clip 52, clips to a second fixed member, shown in this embodiment as a bayonet holder 16, of weapon 14, the mount being held in place by a spring force which urges open collar 30 away from clip 52 as explained hereinbelow. 
     Turning now to FIG. 4, each of the parts of the mount of the present invention are shown. Open collar 30 is secured to block 44 by a threaded shaft 42. One end of threaded shaft 42 is tapered outwardly to form a head 46. A bore 45 in threaded shaft 42 is provided for housing a spring 40 which biases a plastic bearing 38. A top bushing 48 is press fit into hole 47 in block 44. A bottom bushing 50 is press fit into hole 49 of block 44. Threaded shaft 42 is pushed from the bottom of block 44 into bottom bushing 50, through top bushing 48, and is screwed into open collar 30. An elevation thumb wheel 32 is sandwiched within block 44 and threadedly engaged with threaded shaft 42. Spring 36 biases ball bearing 34 against the edge of thumb wheel 32, which includes a plurality of detents 33 for accommodating the ball bearing 34, in order to prevent a change in elevation setting due to vibration or other unintended movement of thumb wheel 32. By turning thumb wheel 32 clockwise, open collar 30 is raised with respect to block 44. Turning elevation thumb wheel 32 counterclockwise causes open collar 30 to move closer to block 44. Head 46 on threaded shaft 42 prevents open collar 30 from being raised so much that it separates from block 44. Once head 46 contacts bottom bushing 50, further clockwise movement of thumb wheel 32, and resultant upward movement of open collar 30, will be prevented. 
     Block 44 slides in a track 96 in base 86 of the mount. A double spring 84 comprising a component 84B inside a component 84A for added stiffness, biases block 44 toward the front end 83 of base 86. Bores 108 and 110 in base 86 accommodate springs 105, 111 and stub platforms 107, 109 respectively. Springs 105 and 111 bias stub platforms 107 and 109 upwardly against block 44 to compensate for any tolerance variations within block 44 or track 96. A pin 88 is inserted in holes 90, 92 at the front end 83 of base 86 to limit the sliding movement of block 44 and to prevent block 44 from being inadvertently removed from base 86. 
     A notch 94 is cut in base 86 at the rearward end of track 96. Notch 94 provides a space in which a user can insert his finger to wipe away any mud or other debris that would otherwise collect in track 96 and interfere with the sliding operation of block 44 in base 86. 
     Second block, or &#34;clip&#34; 52 is slidably mounted for side to side movement within track 100 of base 86, toward the rear end 85 of base 86. Second block 52 contains a notch 82 adapted for mating engagement with a portion of bayonet holder 16 of a firearm 14 as shown in FIGS. 1-3. A lever arm 56 is pivotally mounted by pin 60, which is inserted into hole 80 of block 52. Tab 55 on lever arm 56 extends into notch 82 of second block 52. Spring 62 spring loads tab 55 into notch 82 to lock the second block 52 onto the bayonet holder 16 of weapon 14. This locking arrangement is most clearly shown in FIGS. 6 and 7. 
     Second block 52 also includes a U-shaped anti-wobble spring 73 mounted in notch 82 above lever arm 56 by a screw 78 which extends through an opening 77 in the bight portion of spring 73 and is threadedly received in a threaded bore 79 in clip 52. When second block 52 is locked in place on the bayonet holder 16 of weapon 14, the legs 74 and 75 of spring 73 surround bayonet holder 16 (as shown in FIG. 7) to prevent wobble or side to side movement of the clip 52 relative to weapon 14. A thumbscrew 150 can be threaded through threaded bore 152 in the sidewall of clip 52 surrounding notch 82 to contact one of the legs, e.g., leg 75 of spring 73 to cause the legs 74, 75 of U-shaped spring 73 to be securely clamped about bayonet holder 16 to preclude even the slightest side to side or lateral movement of the mount relative to the weapon 14. The thumbscrew 150 has a reduced diameter portion 154 between its head 156 and threaded shank 158 which is seated in a semi-circular opening 160 in a plate 162 threadedly connected by hexagonal-head screws 164, 166 to the side of clip 52. Abutment of enlarged diameter shank 158 with plate 162 upon backing off or unthreading of screw 150 from bore 152 prevents complete disassociation of thumbscrew 150 and clip 52. 
     As shown in FIGS. 9 and 10, the spring 73 may be eliminated entirely and thumbscrew 150 simply provided with plate 160 to contact and clamp the clip 52 to bayonet holder 16 to prevent side to side wobble or lateral movement of the clip 52 relative to weapon 14. 
     As noted hereinabove, however, second block 52 is slidably mounted in track 100 of base 86 for side to side movement relative to base 86. This structure provides for windage adjustment. Windage is the disturbance of air around a moving projectile, such as a bullet. A windage adjustment compensates for the displacement of the bullet by the wind, by slightly shifting the aim of the gunsight. In the present invention, windage adjustment is provided by thumb wheel 70 which has an offset hole 72 for accommodating a pin 68. Thumb wheel 70 fits within circular cut-out portion 98 of base 86. Pin 68 rides in slot 112 of second block 52, as shown in FIG. 8. A ball bearing 64 seated on a stub platform 65 biased by pressure spring 66 rides between second block 52 and thumb wheel 70. 
     In order to assemble the windage adjustment mechanism, thumb wheel 70 is first placed in circular recess 98 of base 86. Second block 52 is then slid into track 100 of base 86. Spring 66, platform 65 and bearing 64 are sandwiched between second block 52 and thumb wheel 70 as second block 52 is slid into track 100. Guide pin 68 is then pushed through hole 72 from underneath base 86, until guide pin 68 is positioned within slot 112 of second block 52. A set screw 102 holds a spring 104 against ball bearing 106 in rear end 85 of base 86. Ball bearing 106 rides against the edge of thumb wheel 70, which contains a plurality of detents 69, to prevent thumb wheel 70 from moving, and hence the windage adjustment from being affected, by vibration or other movement of the mount. 
     The placement of mount 10 on a weapon will now be explained with reference to FIGS. 2 and 3. The first step in placing the mount on the weapon is to place open collar 30 about the weapon barrel 20 to abut the rear of flash suppressor 18. Base 86 is then slid forward relative to the flash suppressor 18 and firearm barrel 20 until second block 52 is in a position to be attached to bayonet holder 16. The rear end of base 86 is then pivoted upwardly toward the firearm, and the base is released to cause it to slide rearward with respect to block 44 in response to the biasing action of spring 84, thereby engaging second block 52 to bayonet holder 16. 
     Although the invention has been described and illustrated with respect to a preferred embodiment thereof, it will be apparent to those skilled in the art that many modifications and changes in the apparatus may be made without departing from the spirit and scope of the invention as defined in the claims appended hereto. For example, a mount in accordance with the present invention can be attached to different types of firearms. If the firearm of interest does not contain a bayonet holder, the mount can be installed between the flash suppressor at the muzzle end of the barrel, and any fixed member, such a bipod attachment, which exists at the other end of the barrel. 
     For purposes of this disclosure, the &#34;ends&#34; of the firearm barrel are not meant to necessarily be the absolute ends of the tube forming the barrel; rather, while one of the ends of the barrel is generally the muzzle of the firearm, the other one of the ends can, for example, be the portion of the barrel which is adjacent the forestock of the firearm. Depending upon the type of firearm used, a mount in accordance with the present invention can utilize the forestock of the weapon as the &#34;first fixed member&#34; or &#34;second fixed member&#34;, with the muzzle end of the barrel, and particularly the flash suppressor mounted thereto, serving as the other &#34;fixed member&#34;. 
     It should be appreciated that the spring biased sliding block arrangement of the present invention can be adapted to attach a wide variety of devices to many different types of firearms.