Abstract
A grip strap is removably attachable to a grip of a firearm using a plunger mounted in the grip and biased by a mainspring which also biases a hammer strut of the firearm.
Claims
1. A firearm, said firearm comprising: a frame defining a grip; a hammer strut positioned within said grip; a cup positioned within said grip; a mainspring positioned within said grip and acting between said hammer strut and said cup; a plunger mounted on said cup and extending through an opening in said grip; a grip strap removably positionable on said grip, said grip strap comprising: a strap portion overlying said frame, said strap portion having first and second ends oppositely disposed; a spur projecting from said first end of said strap portion, said spur engaging a recess in said frame; an aperture positioned in said second end of said strap portion, said aperture receiving said plunger, engagement of said spur with said frame and said plunger with said aperture retaining said grip strap to said grip.
2. The firearm according to claim 1, wherein said aperture is defined by a lug projecting from said second end of said strap portion.
3. The firearm according to claim 2, wherein said lug comprises a ramp surface surrounding said aperture, said ramp surface facing said plunger when said grip strap is retained to said grip.
4. The firearm according to claim 1, further comprising a plate mounted on said grip, said plate defining said opening.
5. The firearm according to claim 4, wherein said plate has a plate surface facing said mainspring, said plate surface surrounding said opening and defining a line of motion along which said plunger moves, such that movement of said plunger toward said mainspring compresses said mainspring.
6. The firearm according to claim 5, wherein said mainspring comprises a coil spring surrounding an axis oriented parallel to said line of motion of said plunger.
7. The firearm according to claim 6, wherein said axis is coaxially aligned with said line of motion.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is a side view of an example pistol and grip strap according to the invention;
(2) FIG. 2 is a partial sectional view of the pistol in FIG. 1;
(3) FIG. 3 is a detailed view of a portion of the pistol of FIG. 1 shown on an enlarged scale;
(4) FIG. 4 is a side view of an example grip strap according to the invention;
(5) FIGS. 5, 6 and 7 illustrate an example method of attaching a grip strap to a pistol; and
(6) FIGS. 8, 9 and 10 illustrate an example method of removing a grip strap from a pistol.
DETAILED DESCRIPTION
(7) FIG. 1 shows an example firearm 10 and grip strap 12 according to the invention. In this example firearm 10 comprises a semiautomatic pistol having a frame 14 defining a grip 16. As shown in FIG. 2, a hammer strut 18 is positioned within the grip 16. The hammer strut 18 is pivotably connected to a hammer 20 which pivots about an axis 22 on frame 14 to strike a firing pin 24 to discharge firearm 10 when a trigger is pulled. The force necessary to pivot hammer 20 is provided by a mainspring 26. Mainspring 26 is positioned within grip 16 and acts between the hammer strut 18 and a cup 28, also positioned within the grip. Cup 28 helps to retain and stabilize mainspring 26 within the grip 16. As shown in FIG. 3, a plunger 30 is mounted on cup 28 and extends in a direction opposite to the mainspring 26 through an opening 32 in the grip 16. In this example embodiment, the opening 32 is defined by a plate 34 mounted on the grip 16. Plate 34 has a plate surface 36 which faces mainspring 26 and surrounds opening 32 to define a line of motion 38 along which plunger 30 moves. In this example embodiment, mainspring 26 comprises a coil spring surrounding an axis 40 which is coaxially aligned with the line of motion 38 of plunger 26. Motion of plunger 26 along the line of motion 38 toward the mainspring 26 compresses the mainspring, which biases both the plunger 30 and the hammer strut 18.
(8) FIG. 4 shows an example grip strap 12 which is removably positionable on grip 16. Grip strap 12 comprises a strap portion 42 which overlies the frame. A spur 44 projects from a first end 46 of the grip strap 12, and an aperture 48 is positioned in a second end 50 of the grip strap. In this example the aperture 48 is defined by a lug 52 which projects from the second end 50 of the grip strap 12. Lug 52 comprises a ramp surface 54 which faces the plunger 30 when the grip strap is positioned on the grip 16. Engagement of the spur 44 with frame 14 and the aperture 48 with the plunger 30 removably retain the grip strap 12 to the grip 16 as described below.
(9) FIGS. 5-7 illustrate an example method according to the invention of attaching the grip strap 12 to the firearm 10. As shown in FIG. 5, grip strap 12 is positioned such that the spur 44 engages a recess 56 in the grip 16. Grip strap 12 is then rotated about spur 44 toward the grip 16. As shown in FIG. 6, lug 52 is positioned such that upon rotation of the grip strap 12, the ramp surface 54 engages plunger 30 and moves the plunger along the line of motion 38, compressing the biasing mainspring 26. As shown in FIG. 7, once the aperture 48 aligns sufficiently with the plunger 30 the mainspring 26 biases the plunger into engagement with the aperture. The plunger 30 and lug 52 cooperate with the spur 44 and recess 56 to securely retain the grip strap 12 to the grip 16.
(10) FIG. 8-10 illustrate an example method according to the invention for removing the grip strap 12 from the firearm 10. As shown in FIG. 8, a tool 58 is inserted into the aperture 48 of lug 52 sufficient to move the plunger 30 against the biasing force of mainspring 26 and out of engagement with the aperture. As shown in FIG. 9, the grip strap 12 may now be rotated away from the grip 16 to disengage the second end 50 of the grip strap from the grip 16. Both the tool 58 and the plunger 30 may have rounded heads to permit easy relative motion between the grip strap and the grip. As shown in FIG. 10, the spur 44 is next disengaged from recess 56 to remove the grip strap 12 from the grip 16.
(11) It is expected that the firearm and grip strap according to the invention, which uses the hammer strut mainspring to bias the plunger as well as the hammer strut, will provide a simpler way to modify the grip of a firearm to accommodate different users by allowing easy substitution of different sized grip straps to fit different sized hands.
