Patent Publication Number: US-8991293-B1

Title: Pistol having a barrel with synchronized cams

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of application Ser. No. 12/987,317 filed on Jan. 10, 2011, now U.S. Pat. No. 8,621,976, and whose entire disclosure is incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention is directed to semi-automatic pistols. More particularly, the present invention is directed to semi-automatic pistols having improved feeding and extraction of ammunition and improved jamming avoidance. 
     It is highly desirable for semi-automatic pistols to have precise controlled timing of all the elements of its firing cycle. Such a design would provide improved feeding and extraction of ammunition, avoidance of jamming, particularly between ammunition and the pistol&#39;s barrel during a firing sequence, and provide improved case extraction and round in-feeding during a firing sequence. 
     BRIEF SUMMARY OF THE INVENTION 
     In a preferred embodiment of the present invention, a semi-automatic pistol is provided which includes a barrel having a bore, a chamber, an outside surface, a front end and a chamber end, a frame, and a slide adapted for linear motion along the frame during a firing sequence. The slide has a forward end and a block end, the forward end having an upper cam follower surface on an inside surface adjacent to the barrel and a lower cam follower surface on the inside surface adjacent to the barrel. The barrel has three cam surfaces, including a ramp cam surface adjacent to the chamber end of the barrel to effect locking and unlocking of the barrel relative to the slide during the firing sequence, a bottom cam surface and a top cam surface. The bottom cam surface and the top cam surface each are on the outside surface of the barrel and extend from the front end toward the chamber end of the barrel. The bottom cam surface has an undulating surface that moves against the lower cam follower surface of the slide and the top cam surface has an undulating surface that moves against the upper cam follower surface of the slide to cause oscillation of the barrel while the slide moves from a battery position to a fully retracted position and back to the battery position during the firing sequence. 
     Preferably, movement of a trigger of the pistol to a firing position causes the slide to retract relative to the frame and a ramp cam follower on the frame to move against the ramp cam surface to cause the chamber end of the barrel to move downward relative to the frame to release the barrel from fixed engagement with the slide to allow the slide to begin movement to a retracted position. 
     A barrel for a semi-automatic pistol is also provided which includes a bore, an outside surface, a front end and a chamber end. The barrel has a bottom cam surface and a top cam surface. The bottom cam surface and the top cam surface are each on the outside surface of the barrel and extend from the front end toward the chamber end of the barrel. The bottom cam surface and said top cam surface each have an undulating surface to cause oscillation of the barrel while the slide moves from a battery position to a fully retracted position and back to the battery position during a firing sequence. The barrel may also include a ramp cam surface adjacent to the chamber end of the barrel to effect locking and unlocking of the barrel relative to a slide of the pistol during a firing sequence. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
       The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein: 
         FIG. 1  is an isometric view of a pistol having a barrel with synchronized cams in accordance with a preferred embodiment of the present invention; 
         FIG. 2  is a left side isometric view of the barrel of the pistol of  FIG. 1 ; 
         FIG. 3  is a side, elevation view of the barrel of  FIG. 2 ; 
         FIG. 4  is a right, side isometric view of the barrel of  FIG. 2 ; 
         FIG. 5  is a cross-sectional view of the pistol having a barrel with synchronized cams of  FIG. 1 , taken substantially along lines I-I of  FIG. 1 , shown in a battery position; 
         FIG. 6  is a cross-sectional view of the pistol having a barrel with synchronized cams of  FIG. 1 , taken substantially along lines I-I of  FIG. 1 , shown in an unlocked position with the slide partially retracted as it moves rearward; 
         FIG. 7  is a cross-sectional view of the pistol having a barrel with synchronized cams of  FIG. 1 , taken substantially along lines I-I of  FIG. 1 , shown in a case pre-ejected position with the slide partially retracted as it moves rearward; 
         FIG. 8  is a cross-sectional view of the pistol having a barrel with synchronized cams of  FIG. 1 , taken substantially along lines I-I of  FIG. 1 , shown in a case ejected position, with the slide partially retracted as it moves rearward; 
         FIG. 9  is a cross-sectional view of the pistol having a barrel with synchronized cams of  FIG. 1 , taken substantially along lines I-I of  FIG. 1 , shown in an open rear position with the slide fully retracted; 
         FIG. 10  is a cross-sectional view of the pistol having a barrel with synchronized cams of  FIG. 1 , taken substantially along lines I-I of  FIG. 1 , shown in a feed-in position, with the slide in a partially retracted position, as it moves forward; and 
         FIG. 11  is a partial cross sectional view of the slide, taken along lines II-II of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention will be illustrated in more detail with reference to the following embodiments, but it should be understood that the present invention is not deemed to be limited thereto. Referring now to the drawings, wherein like reference numbers refer to like elements throughout the several views, there is shown in  FIG. 1  a semi-automatic pistol  10  having a barrel  12  with synchronized cams in accordance with a preferred embodiment of the present invention. The barrel  12  can best be seen in  FIGS. 2-4 . The barrel  12  has a central bore  14 , an outside surface  16 , a front end  18  and a chamber end  20 . As can be seen in FIGS.  1  and  5 - 10 , the semiautomatic pistol  10  includes a frame  22 , a slide  24 , a firing pin assembly  26 , a trigger  28  and other elements common to semiautomatic pistols. The pistol  10  has a firing sequence typical to semi-automatic pistols and, therefore, will not be described in detail here. The slide  24  slides on rails that provide for linear motion of the slide  24  along the frame  22  during a firing sequence. The slide  24  has a forward end  30  and a block end  32 . 
     In accordance with the present invention the barrel  12  is caused by elements of the frame  22  and slide  24  to follow a unique movement during a firing sequence to provide improved feeding and extraction of ammunition, and avoidance of jamming. Specifically, the forward end  30  of the slide  24  has an upper cam follower surface  34  on an inside surface  36  adjacent to the barrel  12 . Additionally, the forward end  30  of the slide  24  has a lower cam follower surface  38  on an inside surface  36  adjacent to the barrel  12 . The barrel  12  preferably has three cam surfaces. First, the barrel  12  has a ramp cam surface  40  adjacent to the chamber end  20  of the barrel  12  to effect locking and unlocking of the barrel  12  relative to the slide  24  during a firing sequence. Second, the barrel  12  has a bottom cam surface  42  on its bottom side  44 . Third, the barrel has a top cam surface  46  on its top side  48 . The bottom cam surface  42  and the top cam surface  46  are each on the outside surface of the barrel  12  and extend from the front end  18  toward the chamber end  20  of the barrel  12 . The bottom cam surface  42  and the top cam surface  46  each have an undulating surface, as can be seen in  FIGS. 2-10  to cause oscillation of the barrel  12  while the slide  24  moves from a battery position (see  FIG. 5 ) to a fully retracted position (see  FIG. 9 ) and back to the battery position during a firing sequence of the pistol.  FIGS. 5-10  depict this movement of the barrel  12  during various instances in the firing sequence, as will be described in more detail below. 
       FIG. 5  depicts a cross-sectional view of the pistol  10  in battery (i.e., firing) position. As can be seen, the cartridge  58  is in the chamber  60  of the barrel  12 , the breech face end  50  of the barrel  12  is abutted against the slide block  52 , and protuberances  54  on the slide are engaged with mating grooves  56  on the barrel  12  to secure the barrel  12  to the slide  24 . Ramp cam follower  66  on the frame  22  (a pin integral to frame  22 ) is stationary at the right side of the ramp cam surface  40  on the bottom of the barrel  12 . 
       FIG. 6  is a cross-sectional view of the pistol  10  immediately subsequent to firing, shown in an unlocked position with the slide partially retracted as it moves rearward. Here, comparing  FIG. 5  to  FIG. 6 , movement of the trigger  28  of the pistol to a firing position causes the slide  24  to begin is rearward travel during a firing sequence such that the ramp cam surface  40  of the barrel  12  moves against the ramp cam follower  66  on the frame  22  to cause the front end  18  of the barrel to move upward and the chamber end  20  of the barrel  12  to move downward relative to the frame  22  to release the barrel  12  from fixed engagement with the slide  24  to allow the slide  24  to begin movement to a retracted position. The ramp cam follower  66  is now located on the left side of the ramp cam surface  40  on the bottom of the barrel  12  (i.e., the barrel  12  has moved relative to the ramp cam follower  66  on the frame). As can be seen, the bullet  62  has left the casing  64  of the cartridge  58  in the chamber  60  of the barrel  12 , the breech face end  50  of the barrel  12  has moved slightly downward off the block  52 , and protuberances  54  on the slide are disengaged with mating grooves  56  on the barrel  12 . The slide  24  has begun its rearward travel. The upper cam follower surface  34  begins to follow the top cam surface  46  of the barrel  12 , and lower cam follower surface  38  begins to follow the bottom cam surface  44  of the barrel  12 , causing the barrel  12  to begin its undulating movement during a firing sequence. The top cam surface  46  and the bottom cam surface  44  may act on their respective cam follower surfaces  34 ,  38  simultaneously at certain points of the travel or the top cam surface  46  and the bottom cam surface  44  may act independently during any specific point of the firing sequence. That is, all cam surfaces and mating cam follower surfaces need not be in contact with one another at all points of the firing sequence. See the slide  24  as shown in  FIG. 11 . 
       FIG. 7  is a cross-sectional view of the pistol  10  shown in a case pre-ejected position with the slide  24  further retracted from the frame  22  as compared with  FIG. 6 , as it moves rearward during a firing sequence.  FIG. 8  is a cross-sectional view of the pistol  10  shown in a case ejected position, with the slide further retracted (but not fully retracted) as it moves rearward.  FIG. 9  is a cross-sectional view of the pistol  10  shown in an open rear position with the slide fully retracted. Finally,  FIG. 10  is a cross-sectional view of the pistol  10  shown in a feed-in position, with the slide in a partially retracted position, as it moves forward during a firing sequence. As can be seen when comparing these figures to one another and to  FIGS. 5 and 6 , the upper cam follower surface  34  generally follows the top cam surface  46  of the barrel  12 , and lower cam follower surface  38  generally follows the bottom cam surface  44  of the barrel  12 , causing the barrel  12  to oscillate during a firing sequence. Again, during any particular point in the firing sequence, the top cam surface  46  may not necessarily be in contact with the upper cam follower surface  34  and the bottom cam surface  44  may not necessarily be in contact with the lower cam follower surface  38 . 
     While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.