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Publication numberUS3564967 A
Publication typeGrant
Publication dateFeb 23, 1971
Filing dateSep 9, 1968
Priority dateSep 9, 1968
Publication numberUS 3564967 A, US 3564967A, US-A-3564967, US3564967 A, US3564967A
InventorsKennedy Ralph C, Violette Paul A La
Original AssigneeColt S Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pistol barrel positioning means
US 3564967 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

United States Patent [72] Inventors Paul A. La Violette North Haven; Ralph C. Kennedy, Wapping, Conn. [211 App]. No. 758,223 [22] Filed Sept. 9, 1968 [45] Patented Feb. 23, 1971 [73] Assignee Colts Inc.

Hartford, Conn.

[54] PISTOL BARREL POSITIONING MEANS 8 Claims, 8 Drawing Figs. [52] U.S. CI 89/163 [51] Int. Cl F41c 5/06 50] Field of Search 89/ l 60, 163,194,195,196,197 [56] References Cited UNITED STATES PATENTS 3,158,064 11/1964 Charron 89/196 2,627,686 2/1953 Shockey 2,889,753 6/1959 Whitney ABSTRACT: An improved muzzle bushing and cam means for use in a firearm of the type in which relative motion occurs between the barrel and slide members. The bushing has a plurality of integral resilient fingers, each having at least one longitudinally curved surface thereon. The bushing and cam means are affixed to the slide members and barrel respectively such that motion between said barrel and slide members causes similar movement between said bushing and cam means, permitting the cam means to fllex the resilient fingers. The fingers are radially interposed between the barrel and slide members such that each time said members return to battery position, the cam means cause the fingers to wedge the barrel and slide members into the same relative position.

BACKGROUND OF THE INVENTION Large clearances between barrel and bushing and bushing and slide have long been known to interfere with the repeatably accurate firing of a pistol. However, in the past these large clearances have been desirable both to minimize manufacturing costs and to minimize the jamming effect of dirt on the mechanism.

Typically, prior attempts to accurize a pistol having a large clearance between barrel and bushing and bushing and slide have utilized an unidirectional transverse spring force either to tilt and muzzle bushing to take up all lateral play or to load the barrel against the bushing in a predetermined direction. Another scheme utilizes a spherical hump on the barrel mated to coact with the bushing bore with negligible clearance therebetween to limit transverse play and yet provide for the necessary pivoting action. All of these schemes are characterized by the following associated faults; viz, closely held clearances between slide, bushing and barrel, which are expensive to produce and are subject to jamming. Also these close tolerances are subject to wear with an ensuring loss of accuracy. Unidirectional transverse loading means provided to take up play are often incapable of overcoming the high magnitude explosive transient shock loads which occur as the bullet travels down the bore; or if the loading means have sufficient magnitude to overcome transient forces, a rapid wear rate occurs which causes pistol accuracy to deteriorate in the absence of a wear compensation mechanism.

SUMMARY or THE INVENTION A unique resilient fingered bushing and cam mechanism provides means to permit a pistol to initially incorporate and permanently retain a high degree of accuracy.

It is an object of this invention to provide means insensitive to wear which positively and reproducibly wedges the barrel of a pistol in a muzzle bushing and the muzzle bushing in a slide member as the pistol is readied for firing.

Another object is to provide a bushing having resilient fingers integral with the body of the bushing, such that the fingers are wedged between barrel and slide members to uniformly take up radial clearances therebetween, with at least one longitudinally curved surface on each finger contacting cam means whereby the barrel is rigidly supported laterally at battery position and yet is provided relative freedom of motion within said slide member during the recoil and battery strokes.

A further object of the invention is to provide cam means positioned to interact with a plurality of resilient fingers each having a longitudinally curved surface thereon such that said cam means deform said fingers as required to wedge together or to release said barrel and slide members.

Yet another object is to provide barrel loading means which permit use of pistol components manufactured to relatively loose tolerances, but simultaneously provide loading means that cause the members subject to relative motion to always return to the same relative positions prior to firing despite said loose tolerances and despite wear caused increases to originally existing clearances.

These and other objects will be apparent to those versed in the art upon examination of the specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a pistol barrel according to one embodiment ofthe present invention.

FIG. 2 is a perspective view of a pistol bushing according to one embodiment of the present invention.

FIG. 3 is a side elevation view partly broken away in section of a pistol utilizing the present invention.

FIG. 4 is a vertical sectional view along the longitudinal axis of the barrel of FIG. 3 of the preferred embodiment of the present invention.

FIG. 5 is an end view along the line 5-5 of the bushing of FIG. 2.

FIG. 6 is a partial end view along the line 6-6 of FIG. 3.

FIG. 7 is a sectional view of a first alternate embodiment of the present invention.

FIG. 8 is a sectional view of a second alternate embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and more particularly to FIG. I, a barrel 10 is shown which embodies the cam mechanism 14 utilized in the present invention. Modifications to the barrel configuration are made according to the type of pistol action, such as straight blowback, rotational blowback, pivot link action, etc. By way of example, FIG. 3 shows a barrel 10 having locking lugs 16 to permit it to function in a specific pistol action such as the COLT .45. The improvement comprises a cam surface 14 positioned on the barrel exterior and shown in FIG. 1 as a frustoconical tapered surface; however, it is to be understood that variants such as a nonfrustoconical cam surface may provide a more desirable action in some specific types of pistol actions.

Referring to FIG. 2, an improved muzzle bushing shown generally at 20 has a cylindrical body 22, an integral flange 25, an axis of symmetry 28, and a plurality of resilient fingers 30 having at least one longitudinally curved surface 34 on each finger. While flange 25 is shown to have a horseshoe shape typical of a COLT .45 bushing, any other appropriate shape may be utilized. Similarly while locking means to retain bushing 20 in a slide may comprise lug 24 on body 22 of finger 30, as shown in FIG. 2 for the COLT .45 configuration, equivalent locking means may be substituted such as external threads on body 22 or flange 25 which can engage the internal threads of a slide or an internal snap ring engaging the slide member outboard of the bushing flange.

In FIG. 3, a COLT .45 pistol is shown to illustrate the elements of the invention with respect to a typical pistol action. It is to be understood that with appropriate modifications, as described in detail later herein, the subject invention when applied to any pistol action will result in improved initial accuracy that will be retained over the operational life of the pistol. Referring to FIG. 3, a slide 40 is axially slideably mounted for reciprocating movement on a frame 44. A bushing, such as bushing 20, is locked to said slide by locking means previously described such that bushing 20 and slide 40 move together as a subassembly. In FIG. 3, the slide is cutaway to show barrel 10 supported by bushing 20. The arrangement of these details is shown in FIG. 4, the section being taken along lines 4-4 of FIG. 6 to include locking lug 24.

Referring to FIG. 4, flange 25 and locking lug 24 of bushing 20 engage slide member 40. Resilient fingers 30 integral with bushing 20 are wedged between the interior of slide 40 and cam surface 14 of barrel 10. With the barrel and slide in relative positions associated with the ready to fire" condition, cam surface 14 bears against longitudinally curved surface 34 on finger 30. Two equivalent forms of protuberance 34 are indicated; the upper one 34' being machined or molded without altering the outer finger surface; and the lower one 34 having an altered outer surface opposite the protuberance caused by a process such as coining or swaging utilized to produce the longitudinally curved surface. The wedging action occurs as the cam surface causes fingers 30 to flex outwardly until the distal ends of fingers 30 contact the slide member. Further axial motion of bushing 20 with respect to barrel I0 continues to force convex surfaces 34 outward; but since the inboard finger ends are restrained, bending of the fingers must occur, wedging barrel 10 into a repetitive position within the slide in such a fashion that the high shock loads associated with firing the pistol cannot cause relative lateral motion between slide and barrel. Thus one each stroke to battery or "ready to fire" condition, barrel 10 is repetitively aligned by a balanced'force applied by the fingers such that high shock loads associated with firing of the pistol cannot cause relative lateral motion between the slide and barrel. It is evident that wear of the inner surface of slide member 40, cam surface 14, distal ends of fingers 30, and longitudinally curved surfaces on fingers 34 will be evenly distributed such that wear will not change the balanced nature of the forces which repetitively align the barrel within the slide in the same relative position after each fir- FIG. 5 is an end view of bushing 20 of FIG. 2, wherein a symmetrical placement of four fingers as used with the COLT .45 pistol action is shown. Modification of the number and placement of the fingers may be required for application of the instant invention to other pistol actions. By way of illustration, the gap, shown as X in FIG. 5, is approximately onefourth inch, and the gap, shown as Y in FIG. 5, is approximately one-eighth inch for the COLT .45 configuration. This symmetrical placement of the fingers insures the balanced force generated by the fingers will be applied to barrel when the fingers are flexed by the cam means 14. In FIG. 6, the relative placement of barrel l0, bushing and slide member 40 is illustrated.

FIG. 7 shows an alternate bushing configuration 720 having a plurality of longitudinally curved surfaces 734 and 735 on each finger in contact with a barrel 710 and slide 740 in the ready to fire position. Bushing 720 is shown in the installed deformed condition. The bushing 720 is shown in the installed fixed to slide 740 has a plurality of fingers 730 interposed between a slide member 740 and a barrel 710 having cam surface 714 thereon. Each finger has an inwardly projecting protuberance 734 and outwardly projecting protuberance 735 which bears against cam surface 714 and the inner surface of slide 740 respectively whereby the cam load applied at or near the distal ends of fingers 730 causes bending of said fingers about pivot protuberances 735, thus deflecting portions of the fingers inwardly to form longitudinal curved surfaces 736 which provide lateral support to barrel l0. Numerous modifications to the FIG. 7 configuration may be envisaged such as the addition of cam means to the inner surface of slide member 740 to coact with protuberance 735.

FIG. 8 shows a second alternate configuration that is essentially an inversion of the mechanism shown in FIGS. 4 and 7. Bushing 820 is affixed to barrel 810 by snap ring 811 or other suitable means such as conventional screw threads and is fixed against rotation by conventional means 5 such as a key (not shown). The cam means comprises at least one cam surface 814 on the inner surface of a slide 840. Bushing 820 has outwardly extending longitudinally curved surfaces at protuberance 835 positioned on a plurality of fingers 830. Protuberances 835 coact with cam surface 814 to bend the distal ends of fingers 830 against barrel 810 to provide lateral support thereto as relative motion between said barrel and slide occurs on the stroke to the ready to fire position.

While reference has been made to a pistol throughout the specification, it must be recognized that the invention can be readily adapted to certain designs of semiautomatic and automatic rifles and relates to firearms in general being limited to pistols. The description and drawings have been set out to illustrate rather than limit the inventive concept, and it must be understood that our invention encompasses all of the various modifications.

We claim:

1. In a firearm comprising barrel and slide members telescopically mounted to permit relative bidirectional sliding movement therebetween:

at least one partially resilient bushing interposed between said members and enveloping said barrel member;

cam means to cause a portion of said bushing to flex to thereby reduce the lateral clearances between said barrel member and said slide member such that the barrel and slide are rigidly and repetitively aligned with each occurrence of the firearm in the ready to fire condition.

2. A firearm, as claimed in claim 1, wherein the bushing comprises the body portion enveloping said barrel member and includes a plurality of resilient fingers integrally connected to said body portion.

3. A bushing, according to claim 2, having integral bushing retention means thereon.

4. A bushing, according to claim 2, having a substantially symmetrical placement of said resilient fingers with respect to the longitudinal axis of the said body portion of said bushing such that the force generated by said resilient fingers compensates the effect of wear of said bushing, slide and barrel to maintain firearm accuracy.

5. A bushing, according to claim 2, comprising fingers each having at least one longitudinally curved surface thereon.

6. Cam means, according to claim 1, comprising at least one sloped surface one the exterior of said barrel member.

7. Cam means, according to claim 1, comprising at least one sloped surface on the interior of said slide member.

8. A pistol comprising in combination:

a frame;

a slide member axially movable on said frame;

a bushing fixed within said slide member, said bushing having a body portion with a bore therethrough and fastening means thereon to cooperate with said slide member, a plurality of symmetrically arranged resilient fingers integral with said body portion each having at least one longitudinally curved surface thereon;

a barrel positioned within the bore of said bushing, said barrel having a frustoconical cam surface thereon adapted to contact at least one of said longitudinally curved surfaces on each of said resilient fingers such that on recoil stroke said cam surface permits said resilient fingers to contract diametrically, and on battery stroke said cam surface causes said fingers to expand diametrically to thereby remove lateral clearances between said barrel and slide and repetitively align said barrel and slide each time the ready to fire position is approached.

ggggg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 564 ,967 Dated F r ary 23 1971 lnvent fl Paul A. LaViolette and Ralph C. Kennedy It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:


Column 1, line 23, change "ensuring" to ensuing Column 2, line 69, change "one" to on Column 3, line 22, delete "is shown in the installed" Column 3, line 53, after "general" insert without IN THE CLAIMS:

Claim 6, line 2 (Column 4, line 31) change "one" to Signed and sealed this 13th day of July 1971.

(SEAL) Attest:


.F'LETCHER JR. EDWARD M commissioner of Patents Attesting ffic r

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2627686 *May 18, 1951Feb 10, 1953Shockey Richard LRecoil reducer and accuracy improver
US2889753 *May 9, 1958Jun 9, 1959Whitney George WBarrel positioner for automatic pistol
US3158064 *Jan 23, 1962Nov 24, 1964Smith And Wesson IncFirearm with a pivotable barrel having a spherical hump engaging a slide member
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4173169 *May 9, 1977Nov 6, 1979Beals Jeffrey RSemi-automatic firearm
US4178833 *Oct 18, 1976Dec 18, 1979Miller Fred RSnap ring bearing for a gun barrel bushing
US4483235 *May 20, 1982Nov 20, 1984Aktiebolaget BoforsBearing means for a gun barrel
US5437120 *Dec 10, 1993Aug 1, 1995Richard A. VoitFirearm having improved safety and accuracy features
US5654519 *Apr 11, 1995Aug 5, 1997Heckler & Koch GmbhAutomatic pistol
US5969285 *May 8, 1998Oct 19, 1999Krebs; Marc K.Drop-in barrel for recoil operated pistols
US7389719 *Dec 22, 2005Jun 24, 2008Smith & Wesson Corp.Wire bushing for use with a firearm barrel
US7735411 *Feb 28, 2005Jun 15, 2010Caracal International LlcPistol with semi-rigid locking
US20060185508 *Dec 22, 2005Aug 24, 2006Smith & Wesson Corp.Wire bushing for use with a firearm barrel
US20070256344 *Feb 28, 2005Nov 8, 2007Wilhelm BubitsPistol with Semi-Rigid Locking
DE3219578A1 *May 25, 1982Dec 30, 1982Bofors AbLageranordnung fuer ein geschuetzrohr
DE4443940A1 *Dec 9, 1994Jun 13, 1996Heckler & Koch GmbhSchu▀waffe, insbesondere Selbstladepistole
DE4443940C2 *Dec 9, 1994Nov 12, 1998Heckler & Koch GmbhSelbstladepistole
EP0057733A1 *Feb 5, 1981Aug 18, 1982Llama Gabilondo y Cia. S.A.Semiautomatic hand gun
EP0716283A1 *Dec 6, 1995Jun 12, 1996HECKLER & KOCH GMBHFire arm, in particular self-loading pistol
EP0969236A2Apr 15, 1999Jan 5, 2000Parker Hannifin GmbHKink resistant high pressure hose
WO1998003833A2 *Jul 23, 1997Jan 29, 1998Sigg Hans PeterSelf-loading pistol
WO1998003833A3 *Jul 23, 1997Jun 25, 1998Sigg Hans PeterSelf-loading pistol
U.S. Classification89/163
International ClassificationF41A25/00, F41A25/22
Cooperative ClassificationF41A25/22
European ClassificationF41A25/22
Legal Events
Jul 10, 1987AS03Merger
Effective date: 19870706
Jul 10, 1987ASAssignment
Effective date: 19870706