Abstract:
The semiautomatic pistol has a rigidly fixed barrel and sights attached thereto. The body of the pistol receives a breechbolt that moves axially in line with the fixed barrel. Cartridges are transferred from the magazine up to the action in the breechbolt, and spent cartridge cases are ejected out of a side eject port disposed on the pistol. Dismounting of the breechbolt is facilitated by a pivotal dismounting post at the rear of the eject port.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to firearms, and more particularly to a semiautomatic pistol having a breechbolt slidable and rotatable on the receiver. 
   2. Description of the Related Art 
   The design of the semiautomatic pistol has not changed significantly since the introduction of the Colt .45 Model 1911 in the early 1900s. Since that time, others have made some minor modifications in the basic design, but nothing of a fundamental nature. 
   In the Model 1911 pistol, cartridges are stored in an ammunition clip, which is inserted into the grip of the pistol. Cocking and firing of the gun are accompanied by movement of an external slide, and spent shells are ejected from the top of the gun, where they can be distracting to the shooter. The slide travels a distance on the order of two inches each time the gun is fired, and this limits the cycle time or rate at which successive rounds can be fired. Sights are mounted on the moving slide, which makes aiming difficult, and the sliding mechanism and other parts of the action are subject to substantial wear and mechanical failure. 
   In case of the gun being of a target type, it is nearly impossible to get a secure aim with recoiling sights. Therefore sights should be mounted on places free from recoiling, shaking and locations subject to substantial wear and mechanical failure. On a gun with a reciprocating slide, the sights should be at a most forward location and a most rearward location of the gun on safe and secure places. Given the aforementioned, there would only be one way to mount the breechblock, i.e., from the sides, since front and rear portions are closed. 
   Thus, a semiautomatic pistol solving the aforementioned problems is desired. 
   SUMMARY OF THE INVENTION 
   The semiautomatic pistol has a rigidly fixed barrel and sights attached thereto. The body of the pistol is receives a breechbolt that moves axially in line with the fixed barrel and then rotatably with respect to the fixed barrel axis. Cartridges are transferred from the magazine up to the action in the breechbolt, and spent cartridge cases are ejected out of the eject port. Sights are attached to front and rear sections of the fixed barrel. 
   These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  side view of the semiautomatic pistol according to the present invention. 
       FIG. 2  is a side view of the semiautomatic pistol according to the present invention, showing slider action according to the present invention. 
       FIG. 3  is a perspective view of the semiautomatic pistol according to the present invention, showing the breechbolt rotated. 
       FIGS. 4A and 4B  show exploded perspective views of subassemblies of the semiautomatic pistol according to the present invention. 
       FIG. 5  is a partial side view of the semiautomatic pistol according to the present invention, broken away and partially in section to show details thereof. 
       FIG. 6  is a partial side view of the semiautomatic pistol according to the present invention, broken away and partially in section with the breechbolt drawn. 
       FIG. 7  is a perspective view of the breechbolt of a semiautomatic pistol according to the present invention having alternative retainer elements. 
   

   Similar reference characters denote corresponding features consistently throughout the attached drawings. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As shown in  FIGS. 1-4B , the present invention relates to a semiautomatic pistol  60 , including a barrel  120  having a hollow tubular front portion  400  and a rear portion formed by a top wall  402  that extends away from the front portion  400  of the barrel  120 . A barrel retainer pin  160  is used to attach a rigid receiver  100  to the barrel  120  to form a longitudinally extending eject port  122 . A breechbolt slide post  100   a  extends downward from the barrel rear portion top wall  402  into the receiver  100  at the rear of the eject port  122 . 
   A breechbolt  130  being slidably and rotatably mounted around the breechbolt slide post  100   a  is mounted within the receiver  100  and top wall  402 . The breechbolt  130  includes a front face having a recess  130   c  receiving the forward end of a recoil spring guide  53 , with the rear end of the recoil spring guide  53  received within a recoil spring compressor  52  fixedly mounted to rear distal end of the receiver  100  to bias the breechbolt  130  in a forward orientation. 
   A recoil spring  54  may be wound about the guide  53  and captured between the front face  130   c  of breechbolt  120  and the compressor  52  by retaining an axially engaged recoil spring plug  55  with a recoil spring plug retaining pin  56  that slidably mounts into a vertical bore in breechbolt  130 . Internal walls of the breechbolt side arms  130   b  form an opening capable of receiving a firing pin plunger  50  and firing pin spring  51  therethrough, the firing pin plunger  50  being in an axially sliding relationship relative to the breechbolt  130 . 
   Between the front and rear of breechbolt  130  are indentations in the breechbolt side arm interior walls that form a turn recess  130   a . Turn recess  130   a  functions as a pivot point for axial rotation of the breechbolt  130 . Firing pin  49  is movably disposed inside front portion of the breechbolt  130  for operable communication with the firing pin plunger  50 . 
   An extractor  46  is biased forwardly by an extractor plunger  47  that captures an extractor spring  48  between the extractor plunger  47  and a forward end of the breechbolt face for operable communication of a cartridge head directed into a bore of barrel  120 . 
   A top wall lever aperture  404  is disposed in the top wall  402 . Lever  10  is disposed inside the top wall lever aperture  404 , the lever being pivotally attached to the top wall  402  by lever axis pin  190 . The lever  10  is biased by a lever plunger  11  in combination with a lever plunger spring  12 . Adjusting pin  22  in combination with adjusting pin retainer ring  24  is in operable communication with lever  10  in order to adjust pivotal travel distance of the lever  10 . The breechbolt  130  preferably has at least one longitudinally disposed groove  130   d  that the lever  10  can slidably engage to guide reciprocal motion of the breechbolt  130  during firing of the gun  60 . 
   A hammer  40  capable of engaging firing pin plunger  50  is pivotally mounted in the receiver  100  about a hammer axis pin  38  and is disposed in a position for engagement with sear  33  in a cocked orientation of the hammer  40 . Ejector  39  is coaxially mounted with the hammer  40 . Adjusting pin  23  in combination with adjusting pin retainer ring  25  is in operable communication with the hammer assembly in order to limit cocking travel of hammer  40 . A hammer strut  42  is pivotally disposed on the hammer  40  and is retained by hammer strut axis pin  41 . A hammer stop pin  43  is disposed through the receiver to arrest forward pivotal motion of the hammer  40  during firing action. Sear  33  is pivotally mounted in the receiver  100  and retained by sear axis pin  32  while being biased by coaxially mounted sear spring  34 . A main spring  18  is wound about a hammer plunger  19  at an upper end of the main spring  33  and wound about a magazine latch plunger  17  at a lower end of the main spring  33 . A magazine latch  16  is configured to abut against the free end of magazine latch plunger  17  to retain a magazine when the pistol  60  is fully assembled. A hollow main spring housing  44  is attached to the receiver  100  by a main spring housing retaining pin  45  and may extend downward from the receiver  100  at an angle. The main spring  18 , hammer plunger  19  and magazine latch plunger  17  are disposed through a mainspring washer  15  and inside the hollow main spring housing  44 . When handle  140  is attached to receiver  100  a lower handle retainer pin  14  being disposed through the handle  140  and the main spring housing  44  retains handle  140  and magazine latch  16  in operable position. 
   Receptacles  20  and  21  are disposed on the receiver  100  and slidingly engage top of handle  140  for a secure friction fit attachment to the receiver  100 . The handle  140  houses a trigger  27  pivotally about a trigger axis pin  26 , the trigger axis pin  26  being disposed in the receiver  100 . The trigger includes a trigger spring  31  having a trigger spring plunger  30  at its forward end mounted between the trigger and the receiver  100  in order to bias the trigger  27  downwardly in communication with a forward end of a trigger bar  29 . Forward end of trigger bar  29  is pivotally retained in the trigger  27  by trigger bar axis pin  28 . The trigger bar  29  extends rearward of the trigger  27  inside handle  140 . Extreme rear of trigger bar  29  has a boss that engages the sear  33  to displace the sear  33  relative to the hammer  40  permitting the hammer  40  to engage the firing pin plunger  50  directing the firing pin  49  forwardly into engagement with a cartridge (not shown) positioned within a bore of barrel  120 . 
   An elongate safety latch  35  is pivotally disposed in the receiver  100  to engage the trigger  27  in a safety position that prevents firing of the pistol  60 . A breechbolt stop  36  having a breechbolt stop spring  37  is attached to the receiver  100  in a position for operable communication with the breechbolt  130  to limit travel of the breechbolt  130 . 
   The handle  140  is further secured to the receiver by upper handle retainer pin  13  and can receive an automatic pistol magazine of a type known in the art. 
   A rear sight  180 , as well as a front sight  170 , are aligned and mounted to respective rear and front portions of barrel  120  respectively. Advantageously, when firing the gun  60  neither the rear sight  180  nor the front sight  170  moves with respect to the barrel  120  or receiver  100 . 
   As shown in  FIGS. 5-7  an alternatively configured breechbolt  521  may be used. A top strap  501  is attached to and extends rearward away from barrel  301 . The top strap  501  has a breechbolt retainer guiding groove  505   a  and a breechbolt retainer lock rotating recess  505   b . Top strap  501  and receiver  591  attach to form a bottom and top enclosure having an open sided eject port  708 . A breechbolt retaining assembly  512  is mounted in the breechbolt for slidable engagement with receiver  591  and comprises L shaped breechbolt retainer body  512   a  having breechbolt retainer detent grooves  512   c . A breechbolt lock  512   b  has a lateral slot that engages the retainer lever  512 . A breechbolt retainer firing pin crosscut  512   d  is disposed in the breechbolt retainer lock  512   b . Recoil spring plugs  527   a  and  528   a  are held by retainer lever  512 . Recoil springs  525   a  and  526   a  are wound around recoil spring plugs  527   a  and  528   a  respectively. The entire recoil assembly is disposed within the breechbolt  521  with the recoil springs  525   a  and  526   a  having one end fixedly attached to a rear portion of the receiver  591  to provide spring bias to the breechbolt  521 . The breechbolt  521  is slidably engaged between the top strap  501  and the receiver  591 . Interior portion of breechbolt  521  has a solid lateral piece  521   a  joining the sidewalls. The breechbolt retaining detent grooves  512   c  of the retaining assembly  512  being attached to the breechbolt  521  allow the breechbolt  521  to slidably engage a correspondingly grooved receiver  591 . Sidewalls of breechbolt  521  have indentations that form a turn recess  530   a  for pivotal movement of the breechbolt  521  during firing action. Axially extending slidable firing pin  533  is disposed within the breechblock  521  and biased by firing pin spring  534 . Extractor  536  is pivotally disposed within the breachbolt  521  to provide extraction of spent cartridges through the eject port  708 . 
   It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims.