Patent Application
20050055863
The present invention generally relates to cylinder mechanisms used in firearms, and more particularly to an improved mechanism that permits indexing of cylinders used in so-called “solid frame” revolvers.
Solid frame revolvers basically include a frame, a barrel secured to the front of the frame, a cylinder rotatably mounted in the frame and having a ratchet and a plurality of longitudinal chambers bored through the cylinder from its front end to rear end for receiving cartridges, a trigger pivotably mounted to the frame below the cylinder, and a hammer pivotably mounted to the frame behind the cylinder. Unlike other revolvers which pivot the cylinder assembly either upward or laterally out of the frame to give access to the cylinder chambers for loading or unloading, in solid frame revolvers a loading gate cutout in the rear of the frame provides access to the chambers for loading in cartridges through an openable/closeable loading gate. A cylinder pawl, which may be attached to the hammer, rotates the cylinder when the hammer is cocked or when the trigger is pulled. A cylinder latch is provided for preventing rotation of the cylinder when a cartridge is fired. The cylinder latch is configured to releasably engage a plurality of cylinder latch notches each corresponding to one of the cartridge receiving chambers. The cylinder latch engages each of the notches in succession as the cylinder is rotated.
One early approach used to load or unload cartridges in solid frame single action revolver designs originating in the 1800's is as follows. The hammer is pulled back rearward from its fully forward position to a “half cocked” loading notch position, which lowers the cylinder latch downward into the frame so that the cylinder can be freely rotated in a clockwise direction (when viewed from the vantage point of a user at the rear of the revolver). The loading gate is opened and the cylinder manually rotated counter-clockwise until it stops; the cylinder being reverse indexed in the counter-clockwise direction by the pawl which moves forward and upwards (from its rear and downwards position) when the hammer is “half-cocked” and engages the cylinder ratchet. A chamber is now precisely aligned with the loading gate frame cutout at the reverse index position of the cylinder, and a single cartridge may now be either inserted or removed from that chamber. When finished loading or unloading the desired number of cartridges into the cylinder of the revolver, the loading gate is closed. The hammer may now be moved forward and returned to its fully forward position, or pulled back fully rearward to a “full cocked” position if the revolver is ready to be fired.
Another approach used to load and unload cartridges in a newer solid frame revolver design as described in U.S. Pat. No. 4,307,530 eliminates the “half cocked” loading notch position and enhances convenience when loading or unloading the revolver. This design advantageously allows cartridges to be inserted or removed from cylinder chambers with the hammer in the fully forward “uncocked” position. Opening the loading gate lowers the cylinder latch downwards into the frame so that the cylinder can be freely rotated in a clockwise direction without “half cocking” the hammer. The cylinder is reverse indexed in the counter-clockwise direction by the pawl engaging the cylinder ratchet; however, no chamber is precisely aligned with the loading gate frame cutout when the cylinder stops at each reverse index position to allow a cartridge to be loaded or unloaded from the chamber. This is because the pawl is still in its rear and downwards position, and engages the cylinder ratchet at a different location than in the older single action revolver design discussed above. Additional manual manipulation of the cylinder by the user and time is required to precisely align each cylinder chamber with the loading gate frame cutout by sight. Such manual manipulation may be inconvenient and cumbersome to some users. Thus, there is a need for a solid frame revolver which can be more easily and rapidly loaded or unloaded with the hammer in the fully forward position, without the need to first “half-cock” the hammer.
The invention is generally directed to an improved cylinder indexing mechanism or apparatus for a firearm, which in a preferred embodiment is a revolver. In one embodiment, the revolver comprises a supporting structure, a cylinder rotatably carried by the supporting structure and having a plurality of cartridge-receiving chambers. A cylinder indexing member, preferably associated with and carried by the supporting structure, is provided for limiting the rotation of the cylinder. The cylinder has a front and a rear. The indexing member is engageable with the cylinder, and in one embodiment is preferably located behind the cylinder to engage the rear of the cylinder. In one embodiment, the indexing member is a stop pin which preferably is substantially cylindrical in shape. A cartridge loading gate cutout may be provided in the supporting structure through which cartridges are loaded and unloaded into and from the cylinder cartridge-receiving chambers.
The cylinder is configured to be engaged by the stop pin when the cylinder is rotated in a first direction, such that the rotation of the cylinder is restricted or limited in the first direction. Preferably, the cylinder has a limited range of rotation in the first direction such that the rotation of the cylinder is completely stopped when various predetermined positions of the cylinder are reached in relation to the supporting structure (described in more detail below). The rotation of the cylinder is preferably unrestricted or unlimited in a second direction opposite the first direction, such that the cylinder may be freely rotated in the second direction without being stoppingly engaged by the indexing member. Preferably, the first direction is counter-clockwise and the second direction is clockwise when viewed from the vantage point of a user at the rear of the revolver.
As used herein with respect to the rotational motion of the cylinder and when viewed from the vantage point of a user at the rear of the revolver, the “reverse” direction of cylinder rotation is defined as the counterclockwise direction in which cylinder rotation is restricted or limited by the indexing member. The “forward” direction of cylinder rotation is defined as the clockwise direction in which cylinder rotation is unrestricted or unlimited, and freely rotatable.
As used herein with respect to orientation using the revolver as a frame of reference to describe non-rotational direction, “forward” means towards the barrel end of the firearm and “rearward” means towards the handle or stock end of the firearm. “Downwards” means towards the bottom or underside of the firearm and “upwards” means towards the top of the firearm opposite the bottom or underside.
In the foregoing definitions and descriptions provided herein, any reference to either orientation or direction is intended primarily for the convenience in describing preferred embodiments of the invention and is not intended in any way to limit the scope of the present invention thereto.
In one embodiment, the supporting structure is a frame which may further comprise a cylinder frame and a grip frame; the grip frame supporting a handle for a user to hold the revolver. The indexing member may be disposed at least partially in a recess provided in the supporting structure. In one embodiment, the indexing mechanism is slidably moveable with respect to the cylinder.
A biasing member, such as a spring, may be provided in one embodiment which is associated with the indexing member. The spring may be disposed in the supporting structure recess and acts to bias the indexing member forward towards engagement with the cylinder. The spring provides a force that, in one embodiment, substantially maintains contact between the cylinder and indexing member as the cylinder is rotated in either or both the first and second directions. In another embodiment, the recess may further include a step and the indexing member may have a shoulder configured and adapted to engage the step, such that the indexing member is prevented from being ejected from the recess by the spring. Preferably, the spring is coiled around the indexing member. Numerous arrangements of the spring and indexing member are possible and the invention is not limited in this regard.
In another embodiment, the cylinder has a ratchet, preferably located on the back or rear of the cylinder, comprising a plurality of undulating surfaces for engaging the indexing member. In one embodiment, the undulating ratchet surfaces define a plurality of ratchet teeth that are engageable with the indexing member. The ratchet surfaces are configured and arranged on the ratchet to stoppingly engage the indexing member when the cylinder is rotated in the first direction described above, but not in the second direction. Preferably, at least one cartridge-receiving chamber of the cylinder may be stopped in alignment with the cartridge loading gate cutout for loading and unloading cartridges when the indexing member stoppingly engages the ratchet. More preferably, the ratchet surfaces are configured and arranged such that each cartridge-receiving chamber may be selectively aligned with the cartridge loading gate cutout, thereby defining a reverse cylinder rotation index position for each chamber.
In another embodiment in which the cylinder is configured with a plurality of undulating surfaces such as those formed by a ratchet comprising a plurality of teeth, the indexing member functions similarly to a spring-loaded reciprocating piston moving at least partially out of and back into the supporting structure recess (described above) in succession as the cylinder is rotated in the forward direction. The operation of the cylinder and indexing member will be more fully described below.
In one embodiment, the reverse indexing cylinder mechanism further comprises a pawl which is capable of selectively engaging the cylinder. Preferably, the pawl is located behind the cylinder and is selectively engageable with the back or rear of the cylinder. The pawl is moveable from a first position in which the cylinder is engageable with the pawl to a second position wherein the pawl is not engageable with the cylinder. In one embodiment, the pawl makes a pivotal movement about a pivot point in traveling between the first and second positions. Preferably, the pawl does not contact the frame when the pawl is in the first position. Also, preferably, the pawl contacts the cylinder supporting structure or frame to move the pawl into and hold the pawl in the second position. In one embodiment, the pawl has a lobe or other projection which projects from and extends outwards and downwards from the pawl to contact the frame when the pawl is in the second position. The lobe preferably projects from the bottom of the pawl and may be slightly rounded to promote smooth contact between the frame and pawl as the pawl is selectively and alternatingly moved into and out of contact with the frame between the first and second positions.
Preferably, the supporting structure or frame further comprises a cylinder frame for carrying the cylinder and a grip frame attachable to the cylinder frame. The grip frame may be attached to the bottom of cylinder frame and preferably has a substantially planar portion which is contacted by the pawl to move the pawl into and hold the pawl in the second position noted above. Also preferably, the lobe or projection of the pawl contacts the grip frame to move the pawl into and hold the pawl in the second position.
In one embodiment, the pawl may be mechanically linked or connected to the hammer (either directly or indirectly) whose operation also controls the position of the pawl in either the first or second positions describe above. Preferably, the pawl contacts the frame when the hammer is in a fully forward position (i.e., towards the cylinder and front of the revolver) to hold the pawl in the second position described above, wherein the pawl is not engageable with the cylinder. When the hammer is pulled rearwards from the fully forward position, the pawl and hammer are interconnected such that contact is broken between the pawl and frame. This releases the pawl allowing it to move forwards to engage the cylinder, in the first position described above. Preferably, the linkage or connection between pawl and hammer is arranged and configured such that the pawl moves upwards when the hammer is pulled back rearward from the fully forward position to release contact between the pawl and frame. In one embodiment, a pawl biasing member is provided which biases the pawl towards the cylinder. Thus, when contact is broken between the pawl and frame, the pawl is automatically moved forward by the biasing member to the first position into engagement with the cylinder. Preferably, the biasing member is a spring, such as a flat spring, helical spring, or other suitable type.
Subsequently moving the hammer back rearward from the fully forward position causes the pawl to contact the frame and move rearward out of engagement into the second position described above.
The pawl serves to advance the cylinder rotationally each time the trigger (mechanically linked to the hammer) is pulled to discharge the revolver.
In another embodiment, a cylinder indexing mechanism for a revolver comprises a frame having a cartridge loading gate cutout, a hammer pivotably mounted to the frame for firing the revolver, a cylinder rotatably carried and mounted in the frame and having a plurality of cartridge-receiving chambers, and a stop pin carried by the frame and being engageable with the cylinder. The cylinder is configured such that the stop pin engages and stops rotation of the cylinder when rotated in a first direction, thereby creating a rotational index position for the cylinder in relation to the supporting structure or frame. The index position is predetermined such that at least one of the cartridge-receiving chambers is aligned with the cartridge loading gate cutout in the frame. Preferably, a plurality of index positions is provided so that each chamber may be aligned with the loading gate cutout to load and unload cartridges. In another embodiment, the cylinder is configured such that the cylinder may be freely rotated in a second direction opposite the first direction without stopping engagement between the cylinder and stop pin. This allows the rotational position of the cylinder to be manipulated by the user and is also necessary to allow the cylinder to be properly advanced by the pawl each time after a round is discharged from the revolver, thereby bringing a new unfired cartridge into alignment with the hammer for firing.
The features and advantages of the present invention will become more readily apparent from drawings of the preferred embodiments where like elements are labeled similarly, and in which:
Referring to
Preferably, grip frame 3 has a substantially planar portion or surface 50, as shown in
A cylinder 5 has a front 6 and a back or rear 7, and a centrally-located hub 45 for receiving a pin (not shown) to rotatably mount cylinder 5 to cylinder frame 2. Cylinder 5 is rotatably mounted and carried in cylinder cavity 40 defined by cylinder frame 2, as shown. A plurality of cartridge-receiving chambers 8 are longitudinally bored through cylinder 5 for holding cartridges (the rear of a cartridge 53 is shown in
A cylinder ratchet 9 is preferably disposed on the rear 7 of cylinder 5 for rotating the cylinder while the cylinder is carried in the cylinder frame 2. The ratchet 9 may comprise a plurality of undulating surfaces, such as teeth 10 best shown in
A trigger 11 may be pivotably mounted in cylinder frame 2 and/or grip frame 3, and is generally positioned below cylinder 5 as shown in
A hammer 12 is pivotably mounted preferably in cylinder frame 2 and located behind cylinder 5. In one embodiment, as shown, openings 19 in hammer 12 and corresponding openings 20 in cylinder frame 2 may be provided for pivotably connecting hammer 12 to cylinder frame 2. A hammer retaining pin 51 may be inserted through openings 19, 20 of hammer 12 and cylinder frame 2, respectively, to make the pivotable connection. Hammer 12 moves within slot 46 provided in cylinder frame 2. The hammer 12 is used to fire a round of ammunition, for example, by striking a firing pin (not shown) which in turn contacts a cartridge held in a cylinder chamber 8. The movement of the trigger 11 and hammer 12 may be linked together by a means commonly employed in the art and are employed together to fire the revolver 1.
A pawl 13 may be provided which comprises an upper portion 15 configured for engaging ratchet 9 and a lower portion 16. In one embodiment, pawl 13 is mechanically linked or connected to the hammer (either directly or indirectly) whose operation also controls the movement and position of the pawl (described above). Pawl 13 may be connected to hammer 12 via a cylindrical protrusion 14 which extends laterally outwards from the bottom portion 16 of pawl 13 and which is received in a corresponding opening 17 provided in hammer 12. The location of cylindrical protrusion 14 defines a pivot point “P” on the pawl 13 (see
In one embodiment, as shown in
Pawl 13 is preferably biased in a forward direction towards cylinder 5 by a biasing member. In one embodiment, shown in
As best seen in
With particular reference to
Preferably, a biasing member, such as helical spring 31 best seen in
Preferably, stop pin 30 is configured as shown in
Cylinder ratchet 9 and ratchet teeth 10 are cooperatively configured and located with respect to stop pin 30 such that (i) stop pin 30 will not engage and catch teeth 10 when cylinder 5 is rotated in a forward (clockwise) direction, but (ii) stop pin 30 will engage and catch teeth 10 preferably in a plurality of rotational positions when cylinder 5 is rotated in an opposite reverse (counter-clockwise) direction, thereby forming a plurality of reverse indexing positions for cylinder 5. Preferably, the number of reverse indexing positions equals the number of cylinder chambers 8 such that each chamber has an associated reverse indexing position. Also preferably, the forward direction is clockwise and the reverse direction is counter-clockwise when reviewed from the vantage point of a user at the rear of revolver 1.
As shown in
Cylinder stop pin 30 functions as follows. Preferably, the spring constant (k) of biasing member 31 is selected to maintain contact between cylinder stop pin 30 and cylinder ratchet 9 as cylinder 5 is rotated. In one embodiment, when cylinder 5 is rotated forward or clockwise (viewed from the vantage point of a user at the rear of revolver 1), stop pin 30 rides up and down over the ratchet teeth 10. Cylinder 5 is free to rotate in the clockwise direction as stop pin 30 rides up an down along successive passes of the inclined ramp portion 44 of the ratchet teeth 10 (see
In a preferred embodiment, stop pin 30 is located (but not limited to such a position) closer to the centerline of revolver 1 (coinciding with longitudinal axis “LA” as shown in
Operation of the reverse indexing cylinder mechanism in conjunction with loading or unloading the revolver 1 will now be described with reference to the preferred embodiment described herein, starting with hammer 12 in the fully forward position as shown in
To load or unload a cartridge from the revolver 1, the loading gate (not shown) which covers the loading gate frame cutout 42 is opened with hammer 12 in the fully forward position. Cylinder 5 may be freely rotated in the forward clockwise direction (as described above) until the desired first cylinder chamber 8 is reached. If the first chamber 8 is not precisely aligned with the loading gate frame cutout 42 to load or unload a cartridge, cylinder 5 may be manually rotated in the reverse counter-clockwise direction until it stops; the cylinder reaching a first reverse index position associated with the first chamber 8 as one of the cylinder ratchet teeth 10 catches or engages cylinder stop pin 30 to stop the counter-clockwise rotation of cylinder 5. Stop pin 30 and cylinder ratchet 9 are cooperatively structured and arranged such that when a ratchet tooth 10 is engaged by pin 30, the first chamber 8 will be aligned with loading gate frame cutout 42 sufficient to allow a cartridge to be either inserted into or removed from the first chamber 8 through loading gate frame cutout 42. To access a second chamber 8 for loading or unloading a cartridge, cylinder 5 may continue to be manually rotated clockwise until the second chamber 8 comes into view through the loading gate frame cutout 42. If the user inadvertently rotates cylinder 5 clockwise too far past the point where the second chamber 8 is precisely aligned with loading gate frame cutout 42 to load or unload a cartridge, cylinder 5 may again be similarly rotated counter-clockwise in the same manner described above until a second reverse index position corresponding to the second chamber 8 (created by stop pin 30 engaging a ratchet tooth 10) is reached. The second chamber 8 and loading gate frame cutout 42 are now sufficiently aligned to load or unload the cartridge. The process may repeated for the third chamber 8 and subsequent other chambers in a similar fashion until the desired number of chambers 8 have been loaded or unloaded. The loading gate is then closed and the revolver 1 is readied for further action.
Accordingly, the present invention allows hammer 12 to remain in the “uncocked” position while aligning the cylinder chambers 8 with the loading gate cutout 42 of frame 2 to permit cartridges to be loaded or unloaded from the chambers. It should be noted that the cylinder chambers 8 need only be aligned with loading gate cutout 42 a sufficient degree to allow the unloading or loading of cartridges from the chambers. Completely perfect alignment of cylinder chambers 8 with loading gate 42 is not required.
Further describing the operation of the reverse cylinder indexing mechanism, the revolver's hammer 12 may next be pulled fully back rearward to a “full cock” position if the revolver is ready to fired. As the hammer 12 is pulled back rearward, pawl 12 concomitantly moves upwards (as indicated by directional arrow 60 in
It should be noted that stop pin 30 preferably engages a ratchet tooth 10 at a position lower on cylinder 5 than the pawl 13, preferably near about the 6 o'clock position or bottom of the cylinder 5 (when viewed from the vantage point of a user at the rear of the revolver). By contrast, the pawl preferably engages the cylinder 5 near about the 9 o'clock position (when viewed from the vantage point of a user at the rear of the revolver). It should further be noted that stop pin 30 preferably maintains contact with ratchet 9 while pawl 13 is in a forward position in contact with ratchet 9 as described above.
When hammer 12 is ultimately returned to the forward position, pawl 13 moves back downwards (as indicated by directional arrow 60 in
It will also be appreciated by those skilled in the art that the details of the indexing mechanism described herein are matter of design choice, and the invention is not limited to the particular embodiments described herein. Accordingly, numerous modifications and variations may be made to the indexing mechanism without departing from the spirit of the invention and scope of the claims appended hereto.
While the foregoing description and drawings represent the preferred 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 of the present invention as defined in the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other specific forms, structures, arrangements, proportions, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. One skilled in the art will appreciate that the invention may be used with many modifications of structure, arrangement, proportions, 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 indicated by the appended claims, and not limited to the foregoing description.
Although the present invention is particularly applicable to revolvers, it should be understood that the is invention is not limited in that regard and may be used with any type of firearm, rifle, or weapon of any size having revolving chambers which are manually or automatically loaded with cartridges and/or ordnance.
