Abstract:
A firearm such as a semiautomatic pistol or handgun includes a barrel and a slide with a front aperture for rearward movement of the slide around the barrel during cycling of the slide between forward and rearward positions. A wire bushing is provided between the outer diameter of the barrel and the inner diameter of the aperture of the slide for positioning the barrel within the aperture during cycling. The wire bushing is a spring-like, generally round or O-shaped member (e.g., a bent metal wire) mounted within a groove provided in the slide aperture, with portions of the bushing being bent to lie out of the groove for contacting the barrel. The wire bushing reduces the tolerances between the slide and the barrel, thereby improving operation of the firearm, improves re-location of the barrel within the slide, provides for easier maintenance, and reduces mass, cost, and complexity.

Description:
This application claims the benefit of the following U.S. Provisional Applications: Ser. No. 60/639,187; Ser. No. 60/638,594; Ser. No. 60/638,753; Ser. No. 60/638,593; Ser. No. 60/638,746; Ser. No. 60/638,592; Ser. No. 60/638,751; and Ser. No. 60/638,752, all filed Dec. 22, 2004, and all hereby incorporated by reference herein in their entireties. 

   FIELD OF THE INVENTION 
   The present invention relates generally to firearms and, more particularly, to a bushing for a barrel of a semiautomatic pistol or handgun. 
   BACKGROUND OF THE INVENTION 
   In the operation of certain tilting barrel Browning-type semiautomatic pistols or handguns, a slide element is cycled relative to a frame between battery and retired positions via the firing of cartridges. As a cartridge is fired, the slide is driven rearward into the retired position. A spring provides for the return of the slide in the forward direction and in the process replenishes the handgun with a fresh cartridge stripped from a magazine. 
   As the slide is driven rearward, an aperture in the front of the slide allows the slide to move rearward around the barrel. The barrel is supported at its rearward end via a lug on the barrel, the rearward portion of the lug being ramped to receive the next cartridge in preparation for firing. Tolerance between the slide and the lug allows the slide and the barrel to be decoupled as the slide moves rearward. When the slide moves rearward, the forward end of the barrel moves upward, which facilitates the feeding of a fresh cartridge. 
   In order to locate the position of the barrel within the slide from shot to shot, clearances must exist between the outer diameter of the barrel and the inner diameter of the aperture of the slide through which the barrel is received every time the slide is cycled (either manually or during firing). Various methods exist for locating the barrel within the aperture. One method incorporates spherical bushings or bearings into the aperture of the slide at the points of contact. Such bushings or bearings, while being effective to consistently locate the barrel during cycling, generally complicate the structure of the handgun, add mass, are costly, and make the gun difficult to assemble. The use of spherical bushings typically requires that large tolerances exist between the points of contact on the slide and the barrel. 
   SUMMARY OF THE INVENTION 
   A firearm such as a semiautomatic pistol or handgun includes a barrel and a slide with a front aperture for rearward movement of the slide around the barrel during cycling. An embodiment of the present invention provides a wire bushing between the outer diameter of the barrel and the inner diameter of the aperture of the slide. The wire bushing reduces the tolerances between the slide and the barrel, thereby improving operation of the firearm. The wiring bushing also provides for improved re-location of the barrel within the slide during cycling of the slide. 
   One advantage of using a wire bushing between the outer diameter of the barrel and the inner diameter of the aperture of the slide, as described herein, is that the overall mass of the handgun is easily reduced. Reducing the mass improves the comfort level of the firearm. Utilizing a wire bushing also reduces the complexity associated with firearms in which bearings are used as the contact point between the slide and the barrel, reduces cost, and provides for easier maintenance. 
   In one embodiment, the wire bushing is provided as a spring-like wire that is bent to a shape that provides the desired contact between the barrel and the slide. The wire bushing may be generally round in shape (meaning round in overall shape except as possibly to sections bent or otherwise extending inwards for contacting the barrel) to substantially conform to and fit within a groove provided in the slide aperture, into which the wire bushing is mounted. Certain portions of the wire may deviate from the conforming configuration to contact the barrel. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below: 
       FIG. 1  is a simplified schematic side view of a semiautomatic pistol; 
       FIG. 2  is a simplified schematic side view of the pistol of  FIG. 1  shown with the slide moved to a rearward position on the pistol frame; 
       FIG. 3  is a simplified schematic exploded perspective view of a slide of a semiautomatic pistol; 
       FIG. 4  is a simplified schematic perspective view of the slide of  FIG. 3  showing an aperture in which a wire bushing is accommodated; 
       FIGS. 5 and 6A  are simplified schematic elevational views of embodiments of wire bushings of the present invention; and 
       FIG. 6B  is a cross sectional view of a portion of the slide showing the wire bushing of  FIG. 6A  in place. 
   

   DETAILED DESCRIPTION 
     FIGS. 1 and 2  show one example of a semiautomatic pistol or handgun (hereinafter referred to as “firearm  10 ”) that may incorporate a wire bushing  70  according to an embodiment of the present invention. The firearm  10  comprises a frame  12 , a slide  14 , and a fire control mechanism that operates via actuation of a trigger  22 . The frame  12  is fabricated of a high-impact polymer material, metal, a combination of polymer and metal, or other suitable material. The slide  14  houses a barrel  16  in the forward end thereof. The barrel  16  is cooperatively linked with the slide  14  and, together with the slide  14 , defines a longitudinal firing axis  17 . A rearward end  19  of the barrel  16  is adapted for receiving an ammunition cartridge. 
   The slide  14  is fitted to oppositely positioned slide rails  28  on the frame  12  to effect the reciprocal movement of the slide  14  along the longitudinal firing axis  17 . The rails  28  extend along the underside of the slide  14  in the longitudinal direction and are cooperative with the frame  12  to allow the cycling of the slide  14  between forward (battery) and rearward (retired) positions, as shown in  FIGS. 1 and 2 , respectively. The slide  14  further includes a breech face  32  and an extractor port  34 . The breech face  32  is engagable with the rearward end  19  of the barrel  16  to form a firing chamber when the slide  14  is disposed forwardly on the frame  12  ( FIG. 1 ). An ejection mechanism provides for the ejection of a cartridge casing  40  in a direction indicated by an arrow  42  upon firing the firearm  10  or manually cycling the slide  14 . 
   Referring now to  FIG. 3 , the slide  14  has a dosed rearward end and an open forward end at which an aperture  43  is positioned. The forward-most surface of the dosed rearward end is the breech face  32 . The breech face  32  includes an opening  48  through which the forward end of the firing pin is received to strike a cartridge (not shown) and fire the handgun. The undersurface of the closed rearward end of the slide  14  also includes a pickup rail  50 . The pickup rail  50 , upon operation of the handgun, functions to strip cartridges from the magazine and urge the cartridges into position to be fired. 
   The open forward end of the slide  14  houses the barrel  16  through which projectiles of the fired cartridges are directed. The barrel  16  includes a tubular portion  54  that is receivable through the aperture  43  at the forward end of the slide  14  and a rearward portion  56  that, when the barrel  16  is mounted in the slide  14 , doses the extractor port  34  through which spent cartridge casings are ejected. A recoil spring  58  is operatively engaged with the barrel  16 . The operative engagement of the recoil spring  58  with the barrel  16  is effected by the mounting of the recoil spring  58  at a surface  60  of the barrel  16  and at a surface  64  on the slide  14  to allow the slide  14  to be biased rearward into the retired position relative to the barrel  16  and the frame during operation or manual cycling of the handgun. 
   Referring now to  FIGS. 4 and 6B , a wire bushing  70   a ,  70   b  is located within a groove  72  in the defining surfaces of the aperture  43  at the forward end of the slide  14 . For example, the aperture  43  will typically be defined by a cylindrical sidewall  44  extending from the fore end of the slide part ways down the longitudinal axis of the slide. The groove  72  may comprise a shallow channel, generally coaxial with the slide axis, formed in the sidewall  44 . The groove  72  may span the circumference of the sidewall  44 /aperture  43 , but more typically there will be a break or discontinuity in the groove as provided by a shoulder  45 , e.g., the groove may be generally C-shaped in longitudinal cross section, for maintaining proper placement and orientation of the wire bushing  70   a ,  70   b  (see  FIG. 6B ). The groove  72  is dimensioned to have a depth that accommodates portions of the wire bushing  70   a ,  70   b  completely within the groove  72  while allowing other portions of the wire bushing  70   a ,  70   b  to extend out of the groove  72  and into the aperture  43 . For example, the inner diameter of the wire bushing  70   a ,  70   b  may engage the outer diameter of the barrel at approximately the ten o&#39;clock and two o&#39;dock positions. Spring-like characteristics of the wire bushing  70   a ,  70   b  urge the barrel downward in the direction of the six o&#39;dock position of the aperture  43  to consistently relocate the position of the barrel and to accommodate upward motion of the barrel as necessary. The wire bushing  70   a ,  70   b  provides sufficient contact between the slide  14  and the barrel at the ten o&#39;clock and two o&#39;clock positions such that when the slide  14  is cycled the barrel is consistently re-located to the same position within the slide  14 . 
   Referring now to  FIGS. 5 ,  6 A, and  6 B, the wire bushing  70   a ,  70   b  (barrel locating means) comprises a wire  80  that is bent to a shape that provides the desired contact between the barrel and the slide. The wire  80  will typically substantially conform to the orientation/configuration of the groove in which the wire bushing  70   a ,  70   b  is mounted. Distances along the length of the wire  80 , however, deviate from the conforming configuration to provide “extension” portions  82  of the wire  80  that contact the barrel (e.g., as stated above, at the ten o&#39;clock and two o&#39;dock positions). In other words, when deployed in the groove  72 , portions  82  of the bushing  70   a ,  70   b  extend out past the peripheral lip of the groove and into the aperture  43  for contacting the barrel  16 . As is shown in  FIG. 5 , the wire  80  of the bushing  70   a  may have two terminal ends  84  that define surfaces/tabs that can be grasped with fingers, pliers, or the like and manipulated to compress the wire bushing  70   a , thereby facilitating its removal from the groove. In the embodiment shown, the wire  80  may approximate the shape of the Greek letter “omega.” As shown in the embodiment in  FIGS. 6A and 6B , the terminal ends  84  of the wire  80  of the bushing  70   b  may be configured to fit within the groove, thereby requiring the wire  80  to be pulled out by the portions  82  of the wire  80  that protrude out of the groove. 
   The wire  80  will typically be formed from a metal or other material having sufficient hardness to withstand the environment of a firearm. Furthermore, the metal from which the wire  80  is formed is sufficiently ductile to allow it to be formed into a clip-like structure or member having a spring rate that allows for the retention of the bushing formed from the wire  80  in a groove in a slide of a firearm. (For example, with reference to  FIG. 5 , when compressed in direction “A” the bushing will tend to flex outwards in a direction “B.”) Moreover, the wire  80  is of sufficient softness so as to buffer the frictional contact encountered during cycling of the slide. In particular, the wire  80  may be fabricated from a metal that is at least as soft as the metals from which the surfaces of the aperture and the barrel are formed. Alternatively, the wire  80  may be coated with a softer metal to impart lubricious qualities to the wire bushing  70 . 
   In one embodiment of the present invention, as described above, a semiautomatic firearm comprises a frame, a slide mounted on the frame and reciprocal thereon, and a barrel mounted inside the slide. The slide has a forward end for housing the barrel and a rearward end in which is housed a firing pin that cooperates with a trigger assembly and a fire control mechanism mounted in the frame. The slide includes an aperture positioned in the forward end thereof to accommodate the barrel and to receive the barrel therethrough as the slide cycles rearward. The aperture at the front of the slide includes a groove disposed therein. A wire bushing is disposed in the groove to locate the position of the barrel in the slide during cycling of the slide. 
   In another embodiment of the present invention, as described above, a slide for a semiautomatic firearm is mountable on a frame and is capable of receiving a barrel longitudinally therein such that upon operation of the slide in conjunction with a frame of the firearm, the barrel is longitudinally received through an aperture at the front of the slide. The defining surfaces of the aperture include a groove in which a wire bushing is housed. The wire bushing allows for dose tolerances to be maintained between the slide and the barrel and provides for consistent re-location of the barrel during cycling of the slide. 
   In yet another embodiment of the present invention, as described above, a bushing for a slide of a semiautomatic firearm comprises a length of wire. The wire is configured for placement in a groove in an aperture of the front of the slide through which a barrel of the firearm extends upon cycling the slide. The wire has a substantially round configuration having two terminal points and at least one portion that deviates from the substantially round configuration. The deviation of the at least one portion is a bend in the wire in the direction of the center of the substantially round configuration. When configured in this manner, the wire defines an interior diameter that provides a close tolerance fit with an outer surface of the barrel. 
   The wire bushing  70   a ,  70   b  may be characterized as having one or more arcuate portions positioned entirely within the groove  72 . These portions do not contact the barrel. The wire bushing further includes one or more straight/linear sections  82  integral with the arcuate portions. The straight sections are configured to at least partially extend beyond the confines of the groove to lie within the aperture for contacting the barrel. The arcuate portion can be thought of as defining a circle circumscribing a perimeter of the wire bushing (see  FIG. 6B ), with the straight sections defining chords on said circle. 
   As should be appreciated, the portions  82  of the wire bushing  70   a ,  70   b  configured to extend out past the edge or lip of the aperture groove  72  may be formed in a manner other than bending, and may be configured other than as shown in  FIGS. 5 and 6  for providing a different degree or character of contact between the barrel and bushing. 
   Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of this disclosure.