Abstract:
A pistol caliber conversion assembly having a slide assembly housing components of lightweight characteristics so as to accept and permit an interchange of a variety of caliber ammunition. The assembly includes a rail and groove arrangement for slidably mounting a slide housing onto the frame and a recoil mechanism for urging a barrel into a reset position after firing. An open lock mechanism selectively engages the slide housing with the frame and sets to an automatic open position upon ejecting of a last round from the ammunition chamber. The critical selection of high strength-to-weight ratio materials permits machining away of excess materials to reduce weight while maintaining sufficient hardness and mass to handle firing loads.

Description:
Priority Claimed on Ser. No. 60-259,940 filed Jan. 2, 2001 now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the field of conversion assemblies for permitting the interchange of a variety of caliber ammunition to be shot and, more particularly, to a slide assembly having lightweight characteristics derived from use of selected materials and adapted to be selectively machined to remove excess material mass. 
     2. Brief Description of the Prior Art 
     In the past, problems and difficulties have been encountered in the pistol armament field which stem from excessive wear between sliding components. This is especially a problem in designing and manufacturing caliber conversion kits so that a lesser caliber ammunition can be fired in a pistol designed to shoot larger center fire ammunition. Almost all caliber conversion kits are composed of lightweight material such as aluminum. Unfortunately, this material is softer than steel which is the material that most larger caliber pistol components are made of. For example, the caliber conversion slide assembly carrying the barrel, bolt, firing pin assembly, extractor, ejector, etc. is of a soft material which does not allow a “Lock Open” feature because of excessive wear that is created when a “Slide Top Lever” engages with the aluminum slide. The “Lock Open” feature is when the slide assembly remains open after the last round has been fired. Therefore, a need has existed to provide a heat treated insert capable of withstanding the wear of constant engagement between the slide stop lever and the lock open insert. 
     Furthermore, prior slide assemblies, including the slide and bolt made as a one-piece construction resulting in a massive use of material, is heavy. Therefore, the manufacturer cannot elect to employ different materials for the slide and the bolt. For example, conventional slide assemblies cannot make the slide of plastic with either an aluminum or steel bolt. Thus, a need has existed to provide a slide assembly whereby different materials can be employed for various components and wherein selected components may be milled or machined to remove unnecessary material in order to lighten the final slide assembly. 
     SUMMARY OF THE INVENTION 
     Accordingly, the above problems and difficulties are avoided by the present invention which provides a pistol frame having a movable slide assembly carried thereon by a groove and rail arrangement. The slide assembly includes a stationary bolt and movable barrel having a recoil mechanism that includes a guide rod with an expansion spring disposed between the bolt and the end of the slide assembly. A lock and release latch mechanism is cooperatively disposed between the frame and the slide assembly that automatically releases the lock to its open position upon ejection of a last round of ammunition. This latter mechanism includes a stop lever operable on the frame to selectively engage and disengage with an insert carried on the slide assembly. The slide assembly has a slide housing and a barrel/bolt combination composed of different materials permitting machining so as to remove unnecessary material mass. 
     Therefore, it is among the primary objects of the present invention to provide a light-weight slide assembly for a pistol having a Lock Open Insert capable of withstanding excessive wear when a Slide Stop Lever engages therewith. 
     Another object resides in providing a slide assembly which includes components such as a slide and a bolt which are composed of different materials and which may be readily machined to remove unnecessary material mass so as to lighten the overall assembly. 
     A further object resides in a novel light-weight slide assembly for a pistol which is able to shoot inexpensive 22 Long Rifle ammunition that were designed to shoot larger center fire ammunition such as 9 mm; 0.40 S and W; 10 mm; and 0.45 auto ammunition. 
     Yet another object of the invention resides in a caliber conversion kit having a light-weight slide assembly assembled with a modular or separate “slide” and “bolt” whereby a two piece design is provided permitting unneeded material to be machined from the slide from under the bolt and further which permits the material composition of the slide and the bolt to be different. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood with reference to the following description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a side elevational view of a pistol having a conversion assembly for accommodating ammunition of different calibers; 
     FIG. 2 is an exploded view of the piston caliber conversion assembly shown in FIG. 1; 
     FIG. 3 is an enlarged side elevation view, partly in section, illustrating the barrel and slide assembly; 
     FIG. 4 is a back end elevational view of the pistol shown in FIG. 3 as taken in the direction of arrows  4 — 4  thereof; 
     FIG. 5 is a front end elevational view taken in the direction of arrows  5 — 5  of FIG. 3; 
     FIG. 6 is a longitudinal cross sectional view of the pistol taken along arrows  6 — 6  of FIG. 3 illustrating components mounted in the pistol; 
     FIG. 7 is a longitudinal cross-sectional view of the pistol shown in FIG. 3 as taken in the direction of arrows  7 — 7  thereof illustrating the components in the slide; 
     FIG. 8 is a side elevational view of the barrel mounted in the slide shown in FIG. 7 with one version of spring return; 
     FIG. 9 is a transverse cross-sectional view of the slide and pistol shown in FIG. 3 as taken in the direction of arrows  9 — 9  thereof; 
     FIGS. 10 and 11 are fragmentary sectional views of the slide and a top elevational view of the barrel illustrating a preferred version of spring biased barrel return; 
     FIG. 12 is a front elevational view of the slide shown in FIG. 10 taken in the direction of arrows  12 — 12  thereof; 
     FIG. 13 is an exploded perspective view of components in the slide; and 
     FIG. 14 is a transverse cross-sectional view of the slide taken in the direction of arrows  14 — 14  of FIG.  13 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     Referring to FIG. 1, a pistol incorporating the present invention is illustrated in the general direction of arrow  10  which includes a pistol frame  11 , slidably supporting a slide assembly  12 , which includes a barrel  13  and a bolt  14  having a firing pin  15 . The slide assembly  12  is adapted to move rectilinearly on the pistol frame  11  in accordance with the arrow  16 . 
     Referring in detail to FIG. 2, it can be seen that the slide assembly  12  includes an elongated slide  17  having an internal cavity which is occupied by the barrel  13 , which further includes a pair of opposing track grooves  20  and  21  for accommodating rails  22  and  23  carried on the midsection of the pistol frame  11  and rear rails  24  and  25  carried at the rear or back end of the pistol frame  11 . The rails are adapted to be introduced into the grooves  20  and  21  via a retainer  26  which holds the rear of the slide assembly. The slide  17  further includes a rear sight  27  as well as a front sight  28 . The bolt  14  is indicated as being within the channel cavity of the slide  17  immediately behind the barrel  13 . However, the firing pin  15 , firing pin block and the extractor spring bias pin are not illustrated in FIG.  2 . The extreme front end of the slide  17  includes a downwardly depending projection  31  having a aperture  32  into which the end of a rod  33  is inserted which forms a part of the recoil mechanism for the barrel  13 . It is noted that the rod  33  includes a circular flange  34  which fits into a slot  35  immediately behind a block  36 . One end of a spring  37  bears against a notch in the block  36 , while the opposite end of the spring  37  bears against the opposing surface of projection  31  to complete the recoil mechanism for the barrel. Immediately behind the slot  35  is a latch block  40  which is insertably received into a latch well  41  in the pistol frame  11 . The well  41  is defined between elements  42  and  43  fixly located in the pistol frame  11 . 
     It is of importance to note that the pistol frame  11  further includes a slide stop lever  44  which is intended to engage with a steel insert  45  carried on the side of the slide  17 . The “Lock Open” feature is when the slide remains open after the last round of ammunition has been fired. The “Lock Open” insert  45  is a heat treated steel insert designed to withstand the wear of the constant engagement between the slide stop lever  44  and the lock open insert  45 . This “Lock Open” feature is not found in any other conversion kit. 
     It is also to be understood that the slide  17  is composed of aluminum material which is anodized so as to be of light-weight. Contrary to conventional practice the slide  17  and the bolt  14  are manufactured and machined individually so as to remove any excess mass material in order to lighten the weight of the slide assembly  12 . The bolt  14  is preferably composed of aluminum with a breech face included. 
     The recoil assembly shown in FIG. 2 is described more completely further on in connection with FIG.  10  and is the preferred construction. However, it is to be understood that an alternative recoil assembly is illustrated in FIGS. 3,  7  and  8  respectively. 
     To complete the pistol, a trigger  46  is included as well as a trigger guard  47  forming a part of the pistol frame. Also, an ammunition chamber is included within the handle  48  for holding a supply of ammunition preparatory for introduction into the ammunition chamber in the slide assembly  12 . 
     Referring now to FIG. 3, it can be seen that the slide assembly is carried on the pistol frame  11  so that the barrel  13  is in the foreword portion of the slide  17  while the bolt  14  occupies the rear end of the slide assembly. The firing pin spring and mount in the bolt  14  is indicated by numeral  50 . The insert  45  is indicated via the broken-way portion of the slide  17  while the release latch  44  is illustrated in its non-lock position. 
     FIGS. 4 and 5 illustrate the rear and front of the pistol  10  as taken in the direction of the respective arrows in FIG.  3 . 
     Referring now to FIG. 7, it can be seen that the insert  45  is carried on the slide  17  and that when the slide  17  is placed on the pistol frame  11 , the insert will engage with the release latch  44 . Shown in FIG. 6 as well, the latch block  40  is in the well so that the slide and pistol frame are secured together, permitting only the slide to move on the rails  22 - 25  inclusive in the respective grooves  20  and  21 . 
     The firing pin assembly bears against a sear which cocks the firing mechanism preparatory for release by the trigger in order to fire a round in the firing chamber. The rail and groove arrangement is shown more clearly in FIG.  9 . 
     An alternative recoil assembly is illustrated in FIGS. 3,  6 , and  8 , wherein a recoil spring  51  is placed around the barrel and at one end engaging a shoulder  52  while the other end butts against the ring  31  of the slide. The slide can move back and forth in accordance with arrow  16  while the barrel  13  remains stationary with the pistol frame  11 . 
     Referring now in detail to FIGS. 10-12 inclusive, the preferred recoil mechanism is indicated which is employed in the embodiment shown in FIG.  2 . The rod  33  is mounted on the pistol frame  11  by means of the flange  34  abutting against a shoulder  39  on the block  36 . The spring  37  is placed about the rod  33  and its forward end butts against the downwardly depending element  31  when the front end of the rod  33  projects through hole  32 . 
     Referring now in detail to FIGS. 13 and 14, it can be seen that the slide  17  has an elongated internal channel into which the bolt  14  is placed and that the insert  45  is carried along the side edge of the slide. The bolt may readily be machined in order to remove excess material mass in order to lighten the bolt. The barrel  13  may also be machined in order to remove material mass so that the slide assembly is light in weight and yet the choice of material between the insert and the latch release  44  permits longevity of usage since material fatigue and wear are reduced. 
     In view of the foregoing, it can be seen that the heat-treated insert engages the cut-out in the slide to keep the slide open. The bolt and the rails are fabricated separately and are not integrally formed with the slide. This allows removal of extra material in the slide in the form of pockets. The novel construction permits excess to areas of the slide which are normally closed or interfere with the integral bolts. The slide moves rearward and the barrel is part of the stop or rearward movement because of the projection block in the well  41 . “Release” is effected by pushing downward and the last bullet follower pushes the release latch  44  upward to keep the slide open. This construction makes the pistol easier to load. FIGS. 8 and 10 illustrate a recoil mechanism which is more conveniently cleanable by means of spring removal and then the barrel is easy to extract. 
     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.