Patent Publication Number: US-8984787-B1

Title: Rotating and translating extractor

Description:
FIELD OF THE INVENTION 
     This invention relates to auto-loading firearms and particularly, extractors for use therewith. 
     BACKGROUND 
     Modern auto-loading pistols having a reciprocating slide mounted atop a frame typically have an extractor mounted on the slide which engages the rim of a chambered cartridge and pulls the cartridge out of the chamber when the slide moves from battery to the open position. Such extractors have a hook positioned at one end which engages the cartridge rim and are pivotably mounted on the slide. To ensure reliable extraction, the hook must engage the cartridge with significant force to prevent the hook from pivoting outwardly and passing over the rim during extraction as the slide moves out of battery. To that end, the extractor is spring biased to force the hook into the rebate of the cartridge. The pivotably mounted extractor also allows the hook to engage a chambered cartridge without breaking because the hook can pivot outwardly from the slide to clear the rim of the chambered cartridge as the slide moves to battery and then snap into the cartridge rebate, ready to extract the cartridge when the slide again moves out of battery. 
     However, the necessary biasing force on the extractor causes the hook to drag across the rim as the slide moves to battery. Moving contact between the hook and the cartridge generates friction which slows the slide and inhibits slide movement to battery. There is clearly a need to reduce the friction between the hook and cartridge to alleviate the drag problem without compromising the reliability of cartridge extraction. 
     SUMMARY 
     The invention concerns an extractor for a auto-loading firearm. In one example embodiment the extractor comprises a body defining a longitudinal axis and having a hook at a first end thereof. A first slot is positioned in the body distal to the first end. The first slot is oriented parallel to the longitudinal axis. A first cam follower is located at the first end. 
     By way of example, the body further comprises a second end opposite the first end. The first slot is positioned between the first and second ends. In an example embodiment, the first slot extends through the body. By way of further example, the first cam follower is positioned on the hook. In a particular example embodiment, the first cam follower comprises a cam follower surface projecting from the hook transversely to the longitudinal axis. By way of a further example, at least a portion of the cam follower surface is oriented angularly relatively to the longitudinal axis. The portion of the cam follower surface may have an orientation angle of about 45° relatively to the longitudinal axis. In another example, at least a portion of the cam follower surface is oriented substantially parallel to the longitudinal axis. In another example, a second cam follower may be positioned on the hook. 
     In a further example embodiment, the body further comprises a second slot contiguous with the first slot. The second slot is oriented parallel to the longitudinal axis in this example. A spring is mounted within the second slot by way of example. 
     The invention further encompasses a slide for an auto-loading firearm. In an example embodiment, the slide comprises an elongate channel formed of a U-shaped sidewall. The channel defines a longitudinal axis. The sidewall has an opening therein. A first cam is positioned on the slide adjacent to the opening. An extractor body is mounted on the example slide and has first and second ends oppositely disposed. The extractor body is movable relatively to the slide in a direction parallel to the longitudinal axis. A first cam follower is located at the first end of the extractor body. The first cam follower is engageable with the first cam. A first spring acts between the slide and the extractor body for biasing the extractor body into engagement with the first cam. A hook is positioned at the first end of the extractor body. The hook is positioned adjacent to the opening in this example. The extractor body is pivotally mounted on the slide for motion of the hook toward and away from the longitudinal axis. 
     In an example embodiment, the first cam comprises a cam surface positioned on the sidewall and facing toward the longitudinal axis. The cam surface may be angularly oriented with respect to the longitudinal axis by way of example. The cam surface may have an orientation angle of about 45° relatively to the longitudinal axis. An example embodiment may further comprise a recess in the sidewall contiguous with the cam surface. In a particular example embodiment, the cam surface is oriented substantially parallel to the longitudinal axis. By way of example, the slide may further comprising a recess in the sidewall contiguous with the cam surface. 
     An example embodiment may further comprise a pin mounted on the slide proximate to the opening. A first slot is positioned in the extractor body. The first slot is oriented parallel to the longitudinal axis and receives the pin. The first slot and the pin cooperate to permit pivoting of the extractor body and motion thereof parallel to the longitudinal axis. 
     In another example embodiment, a second slot is positioned in the extractor body. The second slot is contiguous with the first slot and oriented parallel to the longitudinal axis. The first spring is positioned within the second slot and acts between the pin and the extractor body in this example. By way of example, a second spring is mounted on the slide. In this example the first slot is positioned between the first and second ends of the extractor body. The second spring engages the second end of the extractor body and thereby biases the hook toward the longitudinal axis. 
     By way of example, the first cam follower is positioned on the hook. In another example, the first cam follower comprising a cam follower surface projecting from the hook transversely to the longitudinal axis. In an example embodiment, at least a portion of the cam follower surface is oriented angularly relatively to the longitudinal axis. By way of example, the portion of the cam follower surface may have an orientation angle of about 45° relatively to the longitudinal axis. In a further example, at least a portion of the cam follower surface is oriented substantially parallel to the longitudinal axis. A second cam follower may be positioned on the hook in another example embodiment. 
     The invention also encompasses an auto-loading firearm. In an example embodiment, the auto-loading firearm comprises a frame. A barrel is mounted on the frame and has a bore defining a firing axis. A slide is mounted on the frame and is movable relatively thereto along the firing axis between an open position and a battery position. The slide has an opening therein. A first cam is positioned on the slide adjacent to the opening. An extractor body is mounted on the slide and has first and second ends oppositely disposed. The extractor body is movable relatively to the slide in a direction parallel to the firing axis. A first cam follower is located at the first end of the extractor body. The first cam follower is engageable with the first cam. A first spring acts between the slide and the extractor body for biasing the extractor body toward the barrel and into engagement with the first cam. A hook is positioned at the first end of the extractor body. The hook is positioned adjacent to the opening. The extractor body is pivotally mounted on the slide for motion of the hook toward and away from the firing axis. 
     By way of example, the first cam comprises a cam surface positioned on the sidewall and facing toward the firing axis. In an example embodiment, the cam surface is angularly oriented with respect to the firing axis. For example, the cam surface may have an orientation angle of about 45° relatively to the firing axis. Another example further comprises a recess in the sidewall contiguous with the cam surface. In a particular example embodiment, the cam surface is oriented substantially parallel to the firing axis. By way of example, a recess may be positioned in the sidewall contiguous with the cam surface. 
     In another example embodiment, the auto-loading firearm further comprises a pin mounted on the slide proximate to the opening. A first slot is positioned in the extractor body. The first slot is oriented parallel to the firing axis and receives the pin. The first slot and the pin cooperate to permit pivoting of the extractor body and motion thereof parallel to the firing axis. 
     By way of example, the auto-loading firearm further comprises a second slot positioned in the extractor body. The second slot is contiguous with the first slot and oriented parallel to the firing axis. The first spring is positioned within the second slot and acts between the pin and the extractor body. In another example, the auto-loading firearm further comprises a second spring mounted on the slide. In this example, the first slot is positioned between the first and second ends of the extractor body. The second spring engages the second end of the extractor body and thereby biases the hook toward the firing axis. By way of example, the first cam follower is positioned on the hook. In another example, the first cam follower comprises a cam follower surface projecting from the hook transversely to the firing axis. By way of example, at least a portion of the cam follower surface is oriented angularly relatively to the firing axis. For example, the portion of the cam follower surface may have an orientation angle of about 45° relatively to the firing axis. In another example embodiment, at least a portion of the cam follower surface may be oriented substantially parallel to the firing axis. The example may further comprise a second cam follower positioned on the hook. The second cam follower is engageable with the barrel. By way of example, the auto-loading firearm comprises a pistol. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an example firearm according to the invention; 
         FIG. 2  is an isometric view of a portion of the firearm shown in  FIG. 1  on an enlarged scale; 
         FIG. 2A  is a detailed view of an example component according to the invention; 
         FIG. 3-5  are partial sectional views of a portion of the firearm according to the invention shown in  FIG. 1 ; and 
         FIGS. 6 and 7  are partial sectional views of another embodiment of the firearm according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an example auto-loading pistol  10  having a frame  12  and a barrel  14  mounted on the frame. Barrel  14  has a bore  16  which defines a firing axis  18 . A slide  20  is mounted on the frame  12 . The slide is movable relatively to the frame  12  along firing axis  18  between an open position and a closed or “battery” position (shown). Slide  20  in this example takes the form of an elongate channel  22  formed of a U-shaped side wall  24 . The channel  22  defines a longitudinal axis  26  which, in this example, is coincident with the firing axis  18 . An opening  28  is positioned in the side wall  24  of channel  22 . Opening  28  is an ejector port which permits cartridges, or casings from spent cartridges, to be ejected from the pistol  10  when the slide moves to the open position to extract and eject a cartridge. 
     Extraction is effected by an extractor  30 , shown in detail in  FIGS. 2 and 2A . Extractor  30  comprises a body  32  that defines a longitudinal axis  34 . A hook  36  is positioned at a first end  38  of the body  32 . A first slot  40  is positioned within body  32 , the slot  40  being positioned distal to the first end  38  and oriented parallel to the longitudinal axis  34  defined by the body  32 . In this example the first slot  40  extends through body  32  and receives a pin  42  mounted on the slide  20  proximate to the opening  28 , thereby positioning hook  36  adjacent to the opening  28 . Pin  42  cooperates with the slot  40  to permit pivotal motion of the body  32  about rotational axis  44 , and translational motion of the body  32  parallel to the longitudinal axis  34 . These motions of the body  32  are relative to the slide  20 . A second slot  46  is positioned in body  32  (see also  FIG. 3 ), the second slot being contiguous with the first slot  40  and also oriented parallel to the longitudinal axis  34  of the extractor. A spring  48  is positioned within the second slot  46 . Spring  48  acts between the pin  42  and the body  32  to bias the body along the longitudinal axis  34  and in a direction away from the breech face  50  mounted in the slide  20 . Allowing the body  32  to move longitudinally along axis  34  permits the so-called “flag distance”  52  between the breech face  50  and the hook  36  to vary as necessary to ensure proper ammunition feeding and extraction. The flag distance for prior art extractors normally provides space between the hook  36  and the breech face  50  for the cartridge rim and some clearance, and it is advantageous to make the flag distance  52  as large as possible so that it reliably clears the rim of a cartridge as the cartridge moves from the magazine and into the barrel chamber during feeding. However, the flag distance  52  is limited by the available space between the breech face  50  and the face of the barrel  14  (not shown). As can be appreciated, it is a challenge to establish and maintain the proper flag distance for a fixed extractor. By allowing the extractor  30  to move along axis  34  relatively to the breech face  50 , and biasing the hook  36  away from the breech face  50 , a larger flag distance  52  can be established when it is needed during ammunition feeding, but the extractor will not prevent the slide from moving into battery because contact between the extractor  30  and the barrel face will move the extractor against its biasing spring  48  and toward the breech face  52  as necessary to permit the slide to return to battery, as described in more detail below. 
     A second spring  54  is mounted on the slide  20 , the second spring being oriented transversely to the slide&#39;s longitudinal axis  26 . Spring  54  acts between the slide  20  and a second end  56  of the extractor body  32 , distal from the pin  42 . Spring  54  thus biases the hook  36  in a direction toward the longitudinal axis  26  of the slide  20 , as well as toward the firing axis  18  of the pistol  10  (see also  FIG. 1 ). Allowing the body  34  to pivot about rotation axis  44  defined by the pin  42  permits the hook  36  to pass over and engage the rim of a cartridge which is already chambered as the slide  20  moves into battery. Spring  54  helps to ensure proper engagement between the hook  36  and the rim of a cartridge, as described below. 
     As shown in  FIG. 2A , a first cam follower  58  is located at the first end  38  of the body  32 . In this example embodiment, cam follower  58  comprises a cam follower surface  60  that projects from the hook  36  transversely to the longitudinal axis  34 . At least a portion  60   a  of cam follower surface  60  is oriented angularly relatively to the longitudinal axis  34  of body  32 . In the example extractor  30  shown in  FIG. 2A  the surface portion  60 A has an orientation angle  61  of about 45° . As shown in  FIG. 3 , cam follower  58  cooperates with a first cam  62  positioned on slide  20  adjacent to opening  28 . First cam  62  comprises a cam surface  63  that faces toward the longitudinal axis  26  of the slide  20 . Cam surface  63  may be angularly oriented with respect to the longitudinal axis  26 . In the example shown, the orientation angle  65  of the cam surface is 45° , matched to the orientation angle  61  of the cam follower surface  60  (see  FIG. 2A ). A recess  67  in the sidewall  24  of the slide  20  is contiguous with the cam surface  63 . Recess  67  helps define the cam  62  and permits motion of the hook  36  in a direction away from the firing axis  18  during action operation as described below. 
       FIG. 3  shows the action of pistol  10  during extraction. A cartridge  64  is in the chamber  66  of the barrel. Hook  36  of the extractor  30  is biased toward the firing axis  18  by spring  54  and engages the cartridge rim  68 . Spring  48  biases the extractor body  32  away from the breech face  50  and maintains the cam follower  58  in engagement with the cam  62  on the slide  20 . As the slide  20  moves out of battery and away from the barrel face  70  the hook  36  pulls on the rim  68  and extracts the cartridge  64  from the chamber  66 . Any tendency of the hook  36  to pivot away from the firing axis  18  and ride up and over the rim  68  (and thereby fail to extract the cartridge  64 ) is prevented by the cam  62  as it engages the cam follower  58 . Spring  48  biases the extractor body  32  toward the cam  62  and maintains the cam and cam follower  58  in engagement as the slide  20  moves out of battery. Without the cam  62  and cam follower  58 , engagement between the hook  36  and the rim  68  would depend almost exclusively on the spring  54  biasing the hook  36  toward the firing axis  18 . Use of the cam  62  and cam follower  58  allow the spring  54  to be less stiff than would otherwise be necessary if the spring  54  alone were to maintain the hook  36  in contact with the rim  68  to ensure extraction of cartridge  64 . 
     A less stiff spring  54  is advantageous when the slide  20  moves into battery because the drag on the slide caused by contact between the extractor and the cartridge is lower as a cartridge is stripped and fed into the chamber. A less stiff spring  54  is especially advantageous when a cartridge  64  is already present in the chamber  66  as the slide  20  moves into battery. For this condition, shown in  FIG. 4 , as slide  20  moves into battery, a second cam follower  72  positioned on the hook  36  engages the rim  68  of cartridge  64 . The cam follower  72  is shaped so that the resultant force between the rim  68  and the extractor body  32  pushes the body  32  toward the breech face  50 , compresses biasing spring  48 , and pushes the hook  36  away from the firing axis  18 . Slot  40  permits hook  36  to move relatively to the slide toward the breech face  50 , but the hook  36  cannot initially pivot away from the firing axis  18  because the first cam follower  58  is still engaged with the cam  62  on the slide  20 . As the body  32  moves relatively to the slide  20 , with hook  36  moving toward the breech face  50 , the first cam follower  58  on hook  36  eventually clears the cam  62  on the slide  20  and aligns with the recess  67  contiguous with the cam. This allows the hook  36  to pivot away from the firing axis  18 , compressing spring  54  and clearing the rim  68 . This configuration is captured in  FIG. 4 . Once the hook  36  clears the rim  68 , the spring  54  biases it back toward the firing axis  18  and the hook  36  snaps over the rim  68 . As the slide  20  attains battery (shown in  FIG. 5 ), the second cam follower  72  may engage the barrel face  70 , moving the hook  36  toward the breech face  50  and compressing the spring  48 . 
       FIGS. 6 and 7  illustrate another embodiment of a cam  74  on slide  20  and a cam follower  76  on the extractor  30 . Cam  74  comprises a cam surface  78  that is oriented substantially parallel to the longitudinal axis  26  of the slide  20 . Cam surface  78  is positioned on sidewall  24  of slide  20  and faces the longitudinal axis  26 . Cam follower  76  comprises a cam follower surface  80  that is also substantially parallel to the longitudinal axis  26 . The recess  67  in sidewall  24  is again contiguous with the cam surface  78  and permits the extractor body  32  to pivot and move hook  36  away from the firing axis  18  ( FIG. 6 ) so that the hook can clear the rim  68  of a cartridge  64  already within chamber  66  as the slide moves into battery. As shown in  FIG. 7 , the cam surface  78  of cam  74  cooperates with the cam follower surface  80  on cam follower  76  to prevent rotation of extractor body  32  (and hence motion of hook  36  away from the firing axis  18 ) to ensure that the hook remains engaged with the rim  68  of cartridge  64  during extraction. 
     The rotating and translating extractor according to the invention is expected to improve the functioning of auto-loading firearms by preventing the extractor from disengaging from the cartridge during extraction while enabling the extractor to snap over a cartridge when closing. This is accomplished using an extractor biasing spring with a lower spring constant, which reduces friction between the hook and the cartridge and hence facilitates closing of the slide. The invention also permits a larger flag distance which will lead to more reliable ammunition feeding as well as increased efficiency of production since the flag distance will no longer be a close tolerance dimension.