Abstract:
A firearm with replaceable grip in one embodiment includes a grip frame, a grip, and a rotary camlock mechanism configured to lock and unlock the grip from the grip frame. The camlock mechanism may be rotated between locked and unlocked positions preventing or enabling removal of the grip from the grip frame. In one embodiment, the camlock mechanism includes a movable blocking surface engageable with the grip to block its removal. The camlock mechanism in one configuration may comprise a rotatable locking cam that defines the blocking surface. A camtrack may be provided to convert rotary motion of the cam into linear displacement relative to the grip frame for selectively projecting or retracting the blocking surface relative to the frame.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/899,031 filed Nov. 1, 2013, the entirety of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to firearms, and more particularly to a user replaceable and interchangeable firearm grip. 
     Firearms including auto-loading pistols traditionally are offered with a variety of grip styles. The grips may differ in characteristics such as size, shape, material, and surface textures to suit manufacturer and/or user preferences. Grips may sometimes be attached to the grip frame of the firearm with threaded fasteners and other parts which are easily lost in the field, and may make a grip exchange a cumbersome process. 
     An improved user-replaceable grip is desired. 
     SUMMARY OF THE INVENTION 
     A user-replaceable firearm grip mounting system is disclosed that provides a mechanically simple and quick grip exchange. The system includes a firearm having a grip frame and grip detachably mountable to the frame. A rotatable camlock mechanism is provided which operably locks and unlocks the grip from the grip frame, thereby allowing rapid exchange of different grips. The camlock mechanism may remain mounted to the grip frame during the grip exchange to eliminate or minimize the possibility of losing parts in the field. In one embodiment, the firearm may be a pistol; however, the camlock mechanism disclosed is readily adaptable to any type firearm or non-firearm which includes a pistol-type grip. Accordingly, the invention is not limited to pistols or firearms alone. 
     In one embodiment, a firearm with replaceable grip includes a grip frame defining a grip mounting axis, a grip configured for mounting on the grip frame, and a rotary camlock mechanism configured and operable to lock and unlock the grip from the grip frame. The camlock mechanism is rotationally movable between a first locked position preventing removal of the grip from the grip frame and a second unlocked position allowing removal of the grip from the grip frame. The camlock mechanism includes a blocking surface moveable into and out of engagement with an abutment surface on the grip to prevent removal of the grip from the grip frame. In one configuration, the camlock mechanism comprises a rotatable locking cam. 
     In another embodiment, a firearm with replaceable grip system includes a grip frame defining a grip mounting axis, a grip removably mounted on the grip frame, an abutment surface formed on the grip, and a rotary locking cam rotatably received in a complementary configured open receptacle in the grip frame. The locking cam includes a blocking surface movable between a projecting locked position and a retracted unlocked position. The locking cam further includes an inclined cam track configured to engage the grip frame for converting rotational movement of the locking cam into linear movement with respect to the receptacle. Rotating the locking cam in a first direction moves the blocking surface into alignment with the abutment surface forming the locked position that prevents removal of the grip from the grip frame, and rotating the locking cam in a second direction removes the blocking surface from alignment with the abutment surface forming the unlocked position that allows removal of the grip from the grip frame. In one configuration, the locking cam has a cylindrical shape with circumferentially extending sidewalls. 
     A method for mounting a replaceable grip on a firearm is provided. The method includes: providing a grip frame including a grip mounting axis and a rotary locking cam rotated to an unlocked position; providing a grip including an abutment surface; positioning the grip on the grip frame in a removal position wherein the abutment surface is located in a first axial position along the grip mounting axis; sliding the grip on the grip frame to a mounting position wherein the abutment surface is located in a second axial position along the grip mounting axis; and rotating the locking cam from the unlocked position to a locked position thereby moving a blocking surface on the locking cam into axial alignment with the abutment surface of the grip between the first and second axial positions; wherein the grip is not removable from the grip frame when the locking cam is in the locked position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the preferred embodiments will be described with reference to the following drawings where like elements are labeled similarly, and in which: 
         FIG. 1  is a left side perspective view of a firearm with grip mounting system according to the present disclosure; 
         FIG. 2  is side elevation view showing the grip removed from the grip frame; 
         FIG. 3  is a rear perspective view of the grip frame; 
         FIG. 4  is a perspective view of a grip frame insert mountable in the grip frame; 
         FIGS. 5-7  are perspective and plan views of the grip showing the interior; 
         FIG. 7A  is an enlarged view of the exterior of the grip and a cam operating aperture; 
         FIGS. 8-8E  are various views of a grip insert mountable in the grip; 
         FIG. 9  is a side cross-sectional view of the grip frame showing a cam receptacle; 
         FIG. 10  is a top cross-sectional view of the grip frame showing the cam receptacle; 
         FIG. 11  is a rear perspective view of the grip frame showing a locking cam of a camlock mechanism positioned for insertion in the cam receptacle; 
         FIGS. 12-12H  are various views showing features of the locking cam; 
         FIG. 13  is a rear perspective view of the grip frame with locking cam shown in an assembly position therein; 
         FIG. 14  is a rear view thereof showing the locking cam in the assembly rotational position; 
         FIG. 15  is a side cross-sectional view thereof; 
         FIG. 16  is a top cross-sectional view thereof; 
         FIG. 17  is a rear perspective view of the grip frame with locking cam shown in a rotated unlocked position therein; 
         FIG. 18  is a rear view thereof showing the locking cam in the unlocked rotational position; 
         FIG. 19  is a side cross-sectional view thereof; 
         FIG. 20  is a top cross-sectional view thereof; 
         FIG. 21  is a rear perspective view of the grip frame showing the grip positioned thereon in a downward unlocked and partially mounted position; 
         FIG. 22  is an additional perspective view thereof showing grip top mounting tabs positioned for insertion into mating mounting pockets of the grip frame; 
         FIG. 23  is a side cross-sectional view thereof showing a grip locking rail positioned and slidable over the locking cam; 
         FIG. 24  is an additional side cross-sectional view thereof showing mounting rails of the grip positioned below mating mounting slots in the grip frame; 
         FIG. 25  is a top cross-sectional view thereof showing the locking cam in the retracted unlocked and unblocking position; 
         FIG. 26  is a rear view of the grip frame showing the locking cam in the locked rotational position; 
         FIG. 27  is a rear perspective view thereof of the grip frame showing the grip positioned thereon in an upward locked and fully mounted position; 
         FIG. 28  is an additional perspective view thereof showing grip top mounting tabs inserted in the mating mounting pockets of the grip frame; 
         FIG. 29  is a side cross-sectional view thereof showing the grip locking rail positioned above the locking cam wherein the axial removal path of the locking rail is blocked; 
         FIG. 29A  is an enlarged detail from  FIG. 29  showing the locking cam region; 
         FIG. 30  is an additional side cross-sectional view thereof showing mounting rails of the grip slideably inserted into the mating mounting slots in the grip frame; 
         FIG. 31  is a top cross-sectional view thereof showing the locking cam in the projected locked and blocking position; 
         FIG. 32  is an additional top cross-sectional view thereof showing the mounting rails of the grip inserted into the mating mounting slots of the grip frame; and 
         FIG. 33  is a top cross-sectional view thereof showing the grip top mounting tabs inserted in the mating mounting pockets of the grip frame. 
     
    
    
     All drawing shown herein are schematic and not to scale. Parts given a reference number in one figure may be considered to be the same parts where they appear in other figures without a reference number for brevity unless specifically labeled with a different part number and described herein. Reference to whole numerical figure numbers having related figures with an alphabetical suffix shall be construed as a reference to all the figures beginning with that number unless specifically noted otherwise. 
     DETAILED DESCRIPTION 
     The features and benefits of the invention are illustrated and described herein by reference to preferred but non-limiting exemplary embodiments. This description of the embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. Accordingly, the invention expressly should not be limited to such embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto. 
     In the description of embodiments disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures may be secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. 
     An exemplary firearm incorporating an embodiment of a replaceable grip system according to principles of the present invention will now be described with reference to a semi-automatic pistol. The principles and features of the embodiments disclosed herein, however, may be embodied with equal benefit in other types of hand-held firearms or weapons including without limitation rifles with pistol-type grips, revolvers, grenade launchers, etc. Accordingly, the invention is not limited in its applicability or scope to pistols alone as described herein. The replaceable grip system is also readily adaptable for use in non-firearm related applications such as without limitation power hand tools (e.g. drills, impact drivers, nail guns, etc.) which may benefit from the ability to easily replace hand grips used in such devices to suit different user and/or manufacturer preferences. The replaceable grip allows end users to select grips with different girths to match variations in hand size for comfort and/or other personal preferences such as grip texture, appearance, color, material, etc. 
       FIGS. 1-32  depict a firearm grip mounting system and component parts according to the present disclosure.  FIGS. 1-3  specifically illustrate a full view and rear portion thereof of a pistol embodying the present grip frame and replaceable grip assembly. The pistol  20  includes a grip frame  22  having a horizontally elongated top portion supporting a reciprocating slide  30 , a barrel  40  defining an axial bullet pathway disposed inside the slide with rear chamber  42  therein for holding an ammunition cartridge, and a trigger mechanism  44  supported by the frame for firing the pistol. Barrel  40  defines a longitudinal axis LA of the pistol. 
     The grip frame  22  includes a vertically elongated rear gripping or grasping portion  23  configured for grasping by a user. The grasping portion  23  includes a front wall  24 , opposing rear wall  25 , and opposing lateral sidewalls  26   a  (left),  26   b  (right). The grasping portion  23  defines a grip mounting axis GA and a transverse axis TA oriented perpendicular to axis GA. Grip mounting axis is oriented transversely to longitudinal axis LA and is oriented substantially parallel to the front and rear walls  24 ,  25  of the grasping portion  23 . Grip mounting axis GA defines an axial grip direction and transverse axis TA defines a transverse grip direction. 
     The walls of the grasping portion  23  further define a hollow downwardly open magazine well  51  that slideably and insertably receives a removable magazine  50  configured for holding a plurality of ammunition cartridges. The grasping portion  23  of the grip frame  22  may be disposed and inclined at an angle to vertical as shown for improved grasping ergonomics. 
     Referring to  FIGS. 5-8 , a detachable grip  60  is removably mounted on the grip frame  22 , and more particularly grasping portion  23 . In one embodiment, the grip  60  may have a generally U-shaped body in transverse cross-section including a rear wall  61  defining a backstrap which conjoins a spaced apart pair of sidewalls  62   a ,  62   b  defining side panels. The grip  60  defines a forward facing and open cavity  63  configured to receive a portion of the grip frame  22  therein. The rear and sidewalls of the grip may be vertically elongated and have an axial length (measured vertically albeit at an angle) that may be substantially coextensive with a majority of the corresponding axial length of the grasping portion  23  of the grip frame  22  on which the grip is mounted. In one embodiment, the rear wall  61  of the grip includes mounting features configured to lockingly engage mounting features formed on the rear side of the grip frame, as further described herein. 
     The grip frame  22  and grip  60  include mating pairs of complementary configured guide or mounting slots and guide or mounting rails, respectively. In one embodiment, referring to  FIGS. 1-8 , the grip frame  22  includes a first laterally spaced pair of mounting slots  70  configured to receive a first mating laterally spaced pair of mounting rails  71  formed in the grip  60 . The mounting slots  70  may be oriented substantially parallel to the rear wall  25  of the grip frame  22  so that the mounting rails are freely and uniformly slideable into the slots without binding or increased pressure as the rails become further inserted into the slots. The mounting slots  70  are vertically elongated and may be disposed at the rear wall  25  of the grip frame somewhat proximate to the sidewalls  26   a ,  26   b  and on either side of the grip mounting axis GA. The mating mounting rails  71  may similarly be disposed on the rear wall  61  of the grip  60  inside the cavity  63  somewhat proximate to the sidewalls  62   a ,  62   b . The mounting slots and rails properly locate and position the grip on the grip frame, in addition to securing the grip to the grip frame as further described herein. 
     In one embodiment, the mounting slots  70  of the grip frame  22  may form laterally outward and downwardly facing open recesses  72 . The mounting slots  70  are defined the rear wall  25  of the grip frame  22  and an opposing parallel axially-extending upper surface  73  formed by a raised protrusion  74  on the rear wall  25  of the frame. In one embodiment, the top end of each slot  70  is closed and the bottom end is open (see, e.g.  FIG. 3  and particularly  11 ) to allow axial insertion of the mounting rail  71  into the slot through the open bottom. The closed top end of slots  70  serve to limit the axial insertion depth of the mounting rails  71  into slots  70  thereby ensuring that the grip is fully seated on grip frame  22  (i.e. grasping portion  23 ) so that cam operating aperture  135  is aligned with the centerline CL 2  of cam receptacle  102  for locking/unlocking the grip  60 . 
     The mounting rails  71  may be formed by inwardly facing projections  75  disposed on the grip inside the cavity. In one embodiment, the rails  71  may be formed on L-shaped projections  75  (in transverse cross-section) having one leg attached to the rear wall  61  of the grip  60  and the remaining perpendicular free leg projecting laterally inwards therefrom towards the centerline CL 1  of the grip. The perpendicular leg of the L-shaped mounting rails  71  may be spaced apart from the rear wall  61  of the grip  60  forming a gap therebetween for receiving a portion of the frame protrusion  74  therein when the grip is mounted on the grip frame  22 . 
     In one embodiment, the grip frame  22  and grip  60  includes a second mating pair of complementary configured bottom guide or mounting slots and rails. In one embodiment, with continuing reference to  FIGS. 1-8 , the grip frame  22  includes a second laterally spaced pair of mounting slots  80  configured to receive a second mating laterally spaced pair of mounting rails  81  formed in the grip  60 . The bottom mounting slots  80  and rails  81  may be configured similarly in general to top mounting slots  70  and rails  71  described above and function in a similar manner. The first pair of mounting slots  70  are spaced axially apart from the second pair of mounting slots  80  along the grip mounting axis GA forming a transverse opening or entrance  82  therebetween that allows for insertion of the first pair of mounting rails  71  therein for mounting the grip. The first pair of mounting rails  71  similarly are spaced axially apart from the second pair of mounting rails  81  along the grip centerline CA 1  forming an opening or entrance  83  therebetween that allows insertion of a portion of the raised protrusion  74  of grip frame  22  therein that defines the mounting slots  80 . In other embodiments, the second pair of mounting rails  81  may be formed on a separate raised protrusion  74  on the grip frame  22  (see, e.g.  FIG. 11 ). 
     Interaction between the mounting slots  70 ,  80  and rails  71 ,  81  prevent withdrawal and removal of the grip  60  from the grip frame  22  in a perpendicular direction to the grip mounting axis GA (i.e. along the transverse axis TA) when the rails are positioned in the slots (see, e.g.  FIG. 2 ). In one embodiment, grip frame  22  may include a pair of laterally spaced and raised stop surfaces  141  shown in  FIGS. 3 and 11  to keep the grip  60  from sliding down too far when removing grip. Stop surfaces  141 , formed on a protrusion on rear wall  25  of grip frame  22 , may be positioned to engage the bottom ends of mounting rails  71  (see also  FIGS. 5-7 ). In that configuration, the stop surfaces  141  are disposed at the top ends of each of the bottom mounting slots  80  adjacent the rearwardly open entrance  82  formed between the top and bottom mounting slots  70 ,  80 . The raised structure defining stop surfaces  141  therefore further serves to limit the axial insertion depth of the bottom mounting rails  81  into slots  80 . 
     The grip  60  further includes a pair of top mounting tabs  90  which are slideably and insertably received in a mating pair of tab pockets  91  formed in the grip frame  22  (see, e.g.  FIGS. 3 and 5 . The tabs  90  act to secure the top portion of the grip to the grip frame to further stabilize the grip when fully mounted. Tabs  90  may be formed in the grip cavity  63  in one embodiment. In one embodiment, the tab pockets  91  may be formed at the top of the grasping portion  23  of the grip frame  22  beneath the rear end of the grip frame. 
     The grip  60  also includes an elongated locking rail  64  which is slideably received in a corresponding elongated locking slot  65  formed in the grip frame  22 . In one embodiment, the locking rail  65  may be disposed and axially aligned with the axial centerline of the grip CL 1  being located approximately midway between the lateral sidewalls  62   a ,  62   b  of the grip. Locking rail  64  is equidistantly disposed between mounting rails  71 . The locking slot  65  may similarly be disposed and axially aligned with the grip mounting axis GA of the grip frame being disposed approximately midway between the lateral sides  26   a ,  26   b  of the grip frame  22 . When the grip  60  is mounted on the grip frame  22 , the locking rail  64  is axially alignable with the mounting axis GA and locking slot  65  of the grip frame for locking the grip to the pistol, as further described herein. The locking slot  65  further functions as an alignment guide or slot to facilitate mounting the grip on the grip frame. 
     In some embodiments, grip  60  may also include an alignment rail  132  which is slideably received in a mating alignment groove  134  formed in grip frame  22  (see  FIGS. 5-8 and 11 ). This facilitates properly aligning the grip  60  with the grip frame  22  for mounting and guides the grip along the grip mounting axis GA together with the mounting rail  74  during the mounting process. 
     The firearm grip mounting system further includes a rotary camlock mechanism comprising a rotatable locking cam  100  which is disposed in complementary configured and dimensioned cam receptacle  102  formed in the rear side  25  of the grip frame  22 , and more particularly in grasping portion  23 . Referring to  FIGS. 3, 4, and 11-14 , cam receptacle  102  is rearwardly open for insertably receiving the cam  100 . 
     With continuing reference to  FIGS. 3, 4, and 11-14 , locking cam  100  is rotatably movable between a locked position shown in  FIG. 27  in which the grip cannot be removed from the pistol  20  (i.e. grip frame  22 ) and an unlocked position in shown in  FIG. 23  which the grip may be removed from the pistol. The locked position is also an inward recessed position of the locking cam  100  in which the cam fully retracts inside the cam receptacle  102 . The unlocked position is also an outward projected position of the locking cam  100  in which a portion of the cam projects above the rim  111  of the receptacle  102  to block removal of the grip  60 , as further described herein. 
     The cam  100  is rotationally moveable using an appropriately configured key or tool between a locked position and an unlocked position. In one embodiment, the locking cam has a generally cylindrical body including an outward facing top surface  104  (facing away from the grip frame, an opposing inward facing bottom surface  106  (facing towards the grip frame), and circumferentially extending circular sidewall surfaces  105  extending between the top and bottom. The top surface  104  may include a recessed operating socket  108 , which may extend partially into or completely through the cam body to bottom surface  106  in various embodiments. In one embodiment, the operating socket  108  is centered in the cam top surface  104  between sidewalls  105  and axially aligned with the cam receptacle centerline CL 2  when the cam is mounted therein. The operating socket  108  is configured to receive a working end of a complementary shaped key or tool that may be used to rotate the cam between the locked and unlocked positions. In one embodiment shown, operating socket  108  may be a star shaped hexalobular or T10 socket. This female socket is configured to receive a key or screwdriver having a complementary configured star-shaped male working end which positively engages the socket to rotate the locking cam  100 . In other possible embodiments, the operating socket may be shaped as an elongated slot to be operated with a slotted screwdriver or key. It will be appreciated that numerous other shapes of operating socket may be used. In other possible embodiments, the operating socket may have other such conventional shapes such as for example, without limitation, a cross (e.g. Phillips head), hexagon, square, or others. Other non-conventional and special operating socket shapes may also be used wherein a custom key is provided which is configured to engage a complementary configured operating socket. 
     When the grip  60  is fully mounted on the grip frame  22 , the cam  100  is accessible through a cam operating aperture  135  formed through the rear wall  61  of the grip (see, e.g.  FIGS. 5-8 ) with the key or tool. When the rotary locking cam  100  is not being locked or unlocked, the aperture  135  may be closed by a suitable configured plug or cap (not shown) to prevent ingress of moisture or dirt. 
     The top surface  104  of locking cam  100  may further include a detent recess or pocket  109  configured to engage an inwardly extending free hooked end  110   a  of an elongated resilient locking cantilevered detent arm  110  (see, e.g.  FIGS. 6-7 and 27 ) disposed on the grip  60  for retaining the cam in the locked position during repeating firing cycles of the firearm is firearm. The detent pocket  109  may be arcuately shaped in one embodiment forming a recessed arc segment and may be disposed near the peripheral edge of the top surface  104  as shown in  FIG. 12 . Hooked end  110   a  of cantilevered detent arm  110  is disposed at an angle to the straight portion of arm  110  fixedly connected to the grip  60 . The configuration of the cantilevered detent arm  110  provides a resiliently flexible structure with elastic spring-like properties that allows the hooked end  110   a  to deflect and move transversely to grip mounting axis GA for engaging/disengaging the cam detent pocket  109 . Various embodiments of cantilevered detent arm  110  may be made of plastic or metal. In one embodiment, the detent arm  110  is formed as an integral unitary structural part of the grip  60  such as when the grip is formed of molded polymer or plastic. The hooked end  110   a  and adjacent portion of cantilevered detent arm  110  are configured and dimensioned to project into the cam operating aperture  135  as shown to engage the cam detent pocket  109 . 
     Top surface  104  of locking cam  100  may further include an alignment mark  107  to facilitate inserting the locking cam  100  into the cam receptacle  102  during initial preassembly of the locking system before installing the grip, as further described herein. Alignment mark  107  may be formed as a recessed feature in top surface  104  of cam  100  in the shape of a line segment in one embodiment. In other embodiments, mark  107  may be formed by etching or a painting the shape onto the top surface of the cam. Other types and shapes of marks may be used. 
     Referring to  FIGS. 11 and 12 , the circumferential sidewall surfaces  105  of the cam  100  include at least one recessed cam track  120  configured to movably receive a mating grip retention locking protrusion  124  formed in the inside surface of cam receptacle  102 . In some embodiments, two cam tracks  120  and mating locking protrusions  124  may be provided on opposing sides of the sidewall surfaces. Each cam track  120  includes two opposing closed ends  121 ,  122 . The locking protrusions  124  are movable and travel back and forth in the track  120  between each end as the locking cam  100  is rotated between the locked and unlocked positions, as further described herein. One end of the cam track  120  is a locked end  122  that defines a locked location or position of the locking protrusion  124  in the track. The other end  121  of the cam track is an unlocked end that defines an unlocked location or position of the locking protrusion in the track. 
     The unlocked end  121  location or position of the locking protrusion  124  in the cam track  120  is associated with an inward recessed position of the locking cam  100  in the receptacle  102  (see, e.g.  FIGS. 19 and 23 ) wherein the grip locking rail  64  may slideably move over/past the cam and the grip  60  may be removed from the grip frame  22 . In the recessed position, the bottom surface  106  of the locking cam is located proximate to the bottom of the cam receptacle  102  (i.e. adjacent grip frame rear wall  25 ) as shown. The locked end  122  location or position of the locking protrusion  124  in the cam track  120  is associated with an outward projected position of the locking cam  100  in the receptacle  102  (see, e.g.  FIG. 27 ) wherein the grip locking rail  64  cannot slideably move over/past the cam and the grip  60  is prevented from being removed from the grip frame  22  when the locking rail is positioned above the cam. Accordingly, a top portion including the top surface  104  of the locking cam  100  extends outwards at least partially into and blocks the linear removal/insertion path of the grip locking rail  64 . In the projected position, the bottom surface  106  of the locking cam  100  is spaced apart from the bottom of the cam receptacle (i.e. grip frame rear wall  25 ) forming a gap therebetween as shown in  FIG. 27 . 
     The cam track  120  extends circumferentially along the sidewall surfaces  105  of the locking cam  100  through an angular distance denoted angle A 1  with respect to the center of the locking cam (see  FIG. 14 ). In one embodiment, the cam track  120  may extend circumferentially through an angle A 1  of less than 180 degrees. In this embodiment, less than a one-half turn (i.e. less than 180 degrees) of the locking cam  100  is sufficient to move the cam from the unlocked position (i.e. locking protrusion  124  located in the unlocked end  121  of the cam track  120 ) to the locked position (i.e. locking protrusion  124  located in the locked end  122  of the cam track). Using this arrangement, sufficient circumferential space is provided in the circular sidewall surface  105  of the locking cam  100  to accommodate two opposing cam tracks  120  and locking protrusions  124  each traveling in a respective cam track on opposite sides of the cam. When two cam tracks  120  are used, it should be noted that the locked ends  122  of each track will essentially be diametrically opposed and the unlocked ends  121  of each track will similarly be diametrically opposed as shown. 
     In other possible embodiments, a single cam track and locking protrusion formed in the cam receptacle may be provided. In such embodiments, a cam track angle A 1  equal to or greater than 180 degrees may be used. Numerous other variations are possible in cam track arrangements and angles of movement. 
     The cam track  120  is angularly disposed or inclined with respect to the top and bottom surfaces  104 ,  105  of the cam  100  which imparts an axial motion to the cam in a direction parallel to the centerline CL 2  of the cam receptacle  102  as the locking protrusion  124  travels along the cam track from unlocked end  121  to locked end  122  (reference  FIGS. 11-12 ). The centerline CL 2  of the cam receptacle  120  may be oriented substantially perpendicular and transverse to the mounting axis GA of the grip frame  22 . In one embodiment, the angle A 2  of the cam track  120  to the bottom surface  105  of the cam  100  may be between 0 and 45 degrees (see also  FIG. 15 ). The unlocked and locked ends  121 ,  122  may be non-inclined or flat being oriented approximately parallel to the cam bottom surface  105  to help retain the locking protrusion  124  therein. The locked end  122  of the cam track defining the locked location of the locking protrusion  124  is closer to the bottom surface  105  of the locking cam  100  than the opposing unlocked end  121  defining the unlocked position of the locking protrusion. Accordingly, rotating the cam in opposing rotational directions alternatingly projects and retracts the cam from the receptacle via sliding engagement between the locking protrusion and the cam track surfaces. 
     Referring to  FIGS. 11-12 , an assembly slot  123  which penetrates the bottom surface  105  of the locking cam  100  is further provided for initially mounting the locking cam in the cam receptacle  102 . The assembly slot  123  communicates with the cam track  120  and may be disposed substantially transverse or perpendicular in orientation to the cam track and generally parallel to the centerline CL 2  of the cam receptacle  102  (see, e.g.  FIG. 15 ). In one embodiment, the assembly slot  123  is preferably located between the closed ends  121 ,  122  of the cam track so as to not interfere with the locked and unlocked positions of the locking protrusion  124  in the cam track ends, and more preferably approximately midway between the ends in one non-limiting embodiment. 
     In one embodiment, the locking protrusion(s)  124  may each be in the form of a raised tab which extends radially inwards from the circumferential sidewall surfaces of receptacle  102  and towards the axial centerline CL 2  of the receptacle. To mount the locking cam  100  in the cam receptacle  102 , the cam is slideably and axially inserted into the receptacle along the receptacle centerline CL 2  with an orientation such that the locking protrusion  124  enters the assembly slot  123  of the cam and then enters the cam track  120  between the opposing closed ends  121 ,  122  (see, e.g.  FIGS. 11, 12, and 15 ). The alignment mark  107  may be used to orient the cam  100  properly for insertion into assembly slot  123  by aligning the mark with hole  142  in the grip frame insert  140  and/or locking slot  65  (see also  FIGS. 3-4 ). The cam  100  may then be rotated in a first rotational direction using the key or tool (not shown) to move the locking protrusion  124  into the unlocked location at the first unlocked end  121  of the cam track  120 . The locking cam  100  is now located in an inward recessed position in the grip frame ready for mounting the grip  60  onto the grip frame  22  wherein the locking rail  64  of the grip may freely slide up past the cam (see, e.g.  FIG. 23 ). The top surface of the cam  100  is substantially flush with or slightly recessed below the top rim  111  of the receptacle  102  (see also  FIG. 23 ). 
     It should be noted that the locking cam  100  is rotatable with respect to the receptacle  102  when the locking protrusion  124  is positioned in the cam track  120  (see, e.g.  FIG. 15 ). When the locking protrusion  124  is located within the assembly slot  123 , the cam  100  cannot be rotated. 
     To prevent removal of the grip  60  when fully seated and mounted on grip frame  22 , locking cam  100  includes a blocking surface  130  which is rotationally alignable with a corresponding abutment surface  131  formed on the grip  60  when the cam is in the locked position (see  FIG. 27 ). Referring to  FIGS. 5-8 and 12 , blocking surface  130  is formed on a peripheral portion of cam  100  at the interface between the top surface  104  and sidewalls  105  (see  FIG. 12 ). In one embodiment, the blocking surface may be formed from a full diameter portion of the cylindrical locking cam  100  at that location. Blocking surface  130  may have any suitable shape, which in one exemplary embodiment is arcuately curved a shown. The blocking surface  130  may also be flat in other embodiments. Blocking surface  130  is located diametrically opposite detent pocket  109  so that when the cam  100  is rotated to the locked position, the blocking surface will be positioned at the top or 12 o&#39;clock position of the cam receptacle  102  and the detent pocket is at the bottom or 6 o&#39;clock position. This positions the blocking surface  130  to engage the grip abutment surface  131  and detent pocket  109  to engage the resilient locking cantilevered detent arm  110 . 
     Abutment surface  131  is formed on a portion of the grip  60  above the cam receptacle  102  and axially aligned with grip mounting axis GA when the grip is fully mounted on the pistol  20 . This positions the abutment surface  131  to engage the blocking surface  130  of the cam  100  when the cam is in the locked position, thereby locating the blocking surface in the axial removal path traveled by the abutment surface to prevent the grip&#39;s removal. In one embodiment, the abutment surface  131  of the grip  60  may be formed on a bottom end of locking rail  64 . In other embodiments, the abutment surface  131  may be formed on the grip  60  separately from the locking rail  64 . 
     Various portions of or the entire grip frame  22  and grip  60  may be formed of any suitable material or combination of materials including metals and non-metals. Exemplary, but non-limiting non-metals may include glass or nylon reinforced and unreinforced polymers, fiberglass, graphite composite materials, and others. In one non-limiting embodiment, the grip and grip frame may be made of a reinforced or unreinforced polymer. 
     For reasons including ease of manufacture, the grip mounting rails  71  and locking rail  64  may be formed on a separate prefabricated grip insert  112  which is attached to the body of the grip  60  (see, e.g.  FIGS. 5-8 ). The alignment rail  132 , cam operating aperture  135 , and cantilevered detent arm  110  may further be formed as part of the grip insert  112 . The grip insert  112  may be molded or cast incorporating the foregoing features. In embodiments where the grip insert  112  and grip  60  body may be formed of polymer, the grip body may be over-molded onto the grip insert to embed and incorporate the grip insert into the grip structure. The grip insert  112  may be attached to the grip body using other fabrication techniques, including for example without limitation mechanical fasteners, welding, soldering, and/or adhesives. In some embodiments, the grip insert  112  may be a metal part with the grip  60  body being overmolded around the insert to embed the insert therein. 
     The cam receptacle  102  may also be formed on a separate prefabricated grip frame insert  140  which is attached to the grip frame body. Referring to  FIGS. 3, 4, and 11 , insert  140  may include an alignment hole  142  to facilitate axially aligning the alignment mark  107  on locking cam  100  for assembling the cam in the receptacle  102 . In one embodiment, the grip frame insert  140  and locking cam  100  may each be formed of metal such as without limitation steel to provide a structurally robust and wear-resistant locking mechanism. In other embodiments, the grip frame insert and cam may each be formed of a non-metallic material such as polymer. Preferably, the material used for the grip frame insert  140  and locking cam  100  have a substantially compatible and comparable hardness (e.g. metal and metal, or polymer and polymer) so that one component does not prematurely wear the other when locking or unlocking the grip from the grip frame over time. The grip frame insert  140 , whether made of metal or polymer, may be over-molded with the grip frame  22 . It will be appreciated that in other embodiments the cam receptacle  102  may be molded as a unitary structural part of a one-piece grip frame during the molding process where the receptacle is to made of the same material (i.e. polymer) as the grip frame without the use of an insert. 
     An exemplary method for mounting a replaceable grip on a firearm will now be described with reference to  FIGS. 11-33 .  FIGS. 11-16  show the assembly position of the locking cam  100 .  FIGS. 17-25  show the unlocked position of the locking cam  100  and grip  60 .  FIGS. 26-33  show the locked position of the locking cam  100  and grip  60 . 
     In general, the method includes first providing the pistol  20  which includes the foregoing grip frame  22  with the present camlock mechanism and a grip  60 . The locking cam  100  has been inserted into cam receptacle  102  (see  FIGS. 11-16 ) and mounted on the grip frame  22 . The locking cam  100  has been rotated (clockwise in the figures) to the initial recessed and unlocked rotational position which allows the locking rail  64  to pass over the blocking surface  130  of the cam (see, e.g.  FIGS. 17-25 ) The locking protrusion  124  in cam receptacle  102  is positioned in the first locked end  121  of the cam track  120 . In embodiments, where two cam tracks  120  are provided as shown, each locking protrusion  124  is positioned in the locked end of their respective track. 
     The grip  60  is then positioned behind the rear wall  25  of grip frame  22  and moved forward in a horizontal direction generally non-parallel and transverse to the grip mounting axis GA of the grip frame  22  (along transverse axis TA) to abut the grip with the rear wall of the grip frame. The rear wall  25  and at least portions of the sidewalls  26   a ,  26   b  of the grip frame  22  are concomitantly received in the forwardly open cavity  63  of the grip  60 . Preferably, the mounting rails  71 ,  81  and locking rail  64  of the grip are initially positioned vertically below the lower entrances (i.e. open bottom ends) of the mating mounting slots  70 ,  80  and locking slot  65  of the grip frame  22 . The top mounting rails  71  have a length sized less than the vertical dimension of the rail entrance  82  between the raised protrusions  73 ,  143  to allow insertion of rails  71  through the entrance and against the rear wall  25  of grip frame  22 . This axially aligns the mounting rails  71 ,  81  with their respective mounting slots  70 ,  80 . 
     While holding the grip  60  pressed against the rear of the grip frame  22 , the grip is next slid axially upwards parallel and substantially along the grip mounting axis GA of the grip frame. This moves the mounting rails  71 ,  81  on the grip into and engages the mounting slots  70 ,  80  of the grip frame (see, e.g.  FIGS. 30 and 32 ). The locking rails  71 ,  81  of the grip  60  simultaneously enters and engages the locking slots  70 ,  80  of the grip frame  22 . The grip  60  is preferably raised vertically along the grip frame  22  until the pair of top mounting tabs  90  are slideably and insertably received in the mating pair of tab pockets  91  formed in the grip frame. This positioning also ensures that the pairs of mounting rails  71 ,  81  and locking rail  64  of the grip  60  are fully inserted into their mating mounting slots  70 ,  80  and locking slot  65  of the grip frame  22 . The grip  60  is now in a fully mounted, but yet unlocked to the grip frame. It should be noted that the grip  60  cannot be horizontally removed rearward from the grip frame  22  (transverse to the grip mounting axis GA and grip rear wall  25 ) due to the interlock formed between the mating mounting rails and slots. 
     After the grip  60  is in the foregoing fully mounted position, the locking cam  100  is rotated using an appropriate configured key or tool to move the locking protrusion  124  of the cam receptacle  102  from the unlocked end  121  of the cam track  120  to the opposite locked end  122  (see, e.g.  FIGS. 26-29 ) If two cam tracks  120  are provided, as shown, each locking protrusion  124  moves from its respective unlocked to lock end of the track. This rotational movement creates an outward linear travel of the cam  100  from the grip frame  22  along the cam receptacle centerline CL 2  to move the locking cam from the recessed unlocked position ( FIG. 23 ) to the projected locked position ( FIG. 27 ). This is evident in  FIGS. 29 and 31  show a gap G formed between the bottom surface  106  of locking cam  100  and rear wall  25  of grip frame  22 . The blocking surface  130  on the top portion of the cam  100  now is positioned in and blocks the axial travel pathway of abutment surface  131  on the grip locking rail  64  (oriented parallel to the mounting axis of the grip frame) so that the locking rail cannot be slideably withdrawn from the locking slot  65 . This also prevents the mounting rails  71 ,  81  from being withdrawn from their corresponding mounting slots  70 ,  80 . The mounting and locking rails of the grip are therefore trapped in their respective mounting and locking slots of the grip frame. The locking cam  100  has now been rotated to the locked position which prevents removal of the grip from the grip frame of the pistol.  FIGS. 26-33  show the locked position of the rotary cam mechanism. 
     It bears noting that rotating the cam  100  to the locked position also resiliently engages the hooked end  110   a  of locking cantilevered detent arm  110  with detent pocket  109  of the cam. Advantageously, this maintains the locked position of the cam  100  and prevents rotation to the unlocked position that might be caused by vibrations created by recoil forces from firing the pistol  20 . 
     To remove the grip  60  from the grip frame  22 , the foregoing mounting process is reversed. This permits removal of the first grip  60  and replacement with a second grip which may have at least one feature different than the first grip such as without limitation size, shape, material, and/or surface textures. Advantageously, this permits the pistol user to change grips easily to suit changing grip preferences and/or environmental conditions. 
     While the foregoing description and drawings represent preferred or exemplary embodiments of the present invention, it will be understood that various additions, modifications and substitutions may be made therein without departing from the spirit and scope and range of equivalents of the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, sizes, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. In addition, numerous variations in the methods/processes as applicable described herein may be made without departing from the spirit of the invention. One skilled in the art will further appreciate that the invention may be used with many modifications of structure, arrangement, proportions, sizes, materials, and components and otherwise, used in the practice of the invention, which are particularly adapted to specific environments and operative requirements without departing from the principles of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims and equivalents thereof, and not limited to the foregoing description or embodiments. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.