The present invention generally relates to firearms, and more particularly to an improved device suitable for use with, but not limited to rimfire-type cartridges to indicate the presence of a cartridge in the chamber of a pistol (i.e., a “loaded chamber”).
While the loaded condition of a firearm's chamber is customarily and most positively checked by the user opening the action and visually observing the presence of a cartridge therein, there have been prior devices which attempt to augment this procedure by providing a mechanical device to signal the chamber's state of readiness, particularly in military firearms where opening the chamber and observing the loaded condition of same may not be practical or possible due to the need for stealth. In a known loaded chamber indicator, an opening or window is cut into the rear portion of the barrel or chamber wall. The opening extends radially inwards from the side of the barrel and through the barrel's rear face against which the rim of a cartridge abuts when a cartridge is loaded into the barrel bore. An elongated thin elastic clip is provided that is fixed to the front portion of the barrel at one end. At the opposite end, the clip has a small projection that protrudes through the window in the barrel to contact the side of the cartridge casing when a cartridge is loaded into the barrel. The clip, however, is physically deflected outwards only by a very small amount by the cartridge casing. Moreover, the clip does not protrude beyond the exterior surface of the pistol in a loaded chamber condition, making the indicator not readily noticeable. Both of these factors make it difficult for a pistol user to visually distinguish a loaded chamber condition from an empty chamber condition by use of such devices.
In another known indicator, a very small viewing window or port is similarly cut into in the barrel or chamber wall of a pistol to allow the presence of the cartridge casing in the barrel bore to be seen through the window. Dirt, unburned gun powder residue, carbon build-up, and grease may obscure the small viewing ports and render them ineffective. The viewing port type indicators are also not useable at night or in other darkened environments.
A drawback of the foregoing known loaded chamber indicators is that they are also not suitable for use with all types of known self-contained cartridges currently on the market today because the window cutouts in the rear barrel or chamber reduce structural support of the cartridge casing and rim. In particular, the foregoing indicators are not well-suited for the very popular rimfire-type cartridges, such as the 0.22 Long Rifle, which optimally require substantial structural support of the cartridge casing and rim during firing. In a rimfire cartridge, the impact-sensitive primer material, which is used to ignite the propellant powder (i.e., gunpowder), is distributed inside and around the base of the cartridge casing in the rim. The rim is a relatively thin and narrow laterally-protruding hollow annular structure disposed around the circumference of the cartridge casing at its base. An annular space is contained inside the rim for holding the primer material. Striking the rim from the rear (such as with a firing pin) crushes and flattens the rim together against the rear face of the barrel or chamber. This “squeezing” deformation of the rim creates internal friction in the primer material sandwiched in the narrow annular space within the rim, and ignites the primer which in turn sets off the propellant powder. Accordingly, the casing in the base area, and in particular the rim of the cartridge casing, are intentionally made relatively thin and weak by structural design to be readily deformable. Therefore, a rimfire-type pistol, to provide maximum support to the base and rim of the cartridge to prevent the fragile rimfire casing from bursting during firing, should preferably not contain cutouts in the barrel or chamber area.
The known loaded chamber indicators discussed above all require cutting away of cartridge support provided by the barrel or chamber to allow those indicators to function properly. There has never been a loaded chamber indicator in the prior art that functions in a truly satisfactory fashion on firearms chambered for rimfire-type ammunition, which comprise a large percentage of the firearms sold. Accordingly, there is a need for a loaded chamber indicator that does not undermine support of a cartridge during firing and, in particular, one which functions satisfactorily with rimfire-type ammunition such as the 0.22 Long Rifle.
A preferred embodiment provides a moveable loaded chamber indicator for a pistol that advantageously does not require cutting away of the rear barrel or chamber, thereby providing substantial structural support of the cartridge casing when the cartridge is loaded in the barrel or chamber. The preferred embodiment further advantageously provides a loaded chamber indicator that is more readily noticeable to a pistol user from a visual and tactile standpoint than known indicators.
In a preferred embodiment, the loaded chamber indicator operates by contact with the cartridge rim which remains outside of, and to the rear of or behind the chamber when the cartridge is loaded therein. Accordingly, the structural integrity of the chamber is not compromised by any openings cut through the chamber walls into the chamber like the known indicators discussed above. Therefore, the relatively fragile rimfire cartridge casing may be substantially and properly supported by the chamber.
In a rimfire cartridge, striking the cartridge rim from the lateral or side direction (instead of from the normal rear firing direction as with a firing pin) does not ignite the primer because the “squeezing” deformation of the rim needed to ignite the primer material (discussed above) is not created by impacting the rim from the side. In addition, the arched shape of the rim presented in the lateral direction makes the rim inherently stronger and more resistant to deformation from a blow to the side. Accordingly, the side of the cartridge rim which may conveniently be used to activate the indicator.
A pistol designed according to the preferred embodiment includes a barrel, a housing which may be a receiver preferably coupled to the barrel to define a barrel-receiver assembly, and a chamber capable of holding a cartridge and which is operably associated with the barrel-receiver assembly. In a preferred embodiment, the chamber may be a cylindrical longitudinal bore which may be contained in a chamber block having sidewalls and a rear surface for abuttingly receiving a cartridge having rim. Preferably, the rear surface of the chamber block surrounding the chamber opening is uninterrupted by cutouts and forms a continuous circumferential seat for abuttingly contacting and supporting the rim of the cartridge. In one embodiment, the chamber is sized for receiving a 0.22 caliber cartridge.
An indicating element is provided which preferably operates off contact with the rim of the cartridge. More preferably, in the preferred embodiment, the indicating element operates off contact with the side of the cartridge rim. The indicating element may be pivotally mounted to the barrel-receiver assembly at a pivot defining a pivot point. Preferably, the indicating element is moveable and displaceable in response to contact by the cartridge from a first inactivated position or location, which may correspond to an absence of a cartridge fully-loaded in the chamber (i.e. an unloaded-chamber-indication position), to a second activated position or location, which may correspond to the presence of a cartridge loaded in the chamber (i.e. a loaded-chamber-indication position). In one embodiment, at least a portion of the indicating element protrudes outwards and away from exterior surface of the barrel-receiver assembly in the second position in response to contact by the cartridge. This provides both a visual and tactile indication that a cartridge is loaded in the chamber.
In one embodiment, the indicating element may have a sensor surface configured to contact and detect the cartridge, and a signal area to identify and communicate the presence of a cartridge in the chamber. The sensor surface may be a cam. Preferably, the signal area may protrude outward and away from the exterior surface of the pistol in the second loaded-condition-indication position. The signal area has an ornamental shape which in one embodiment may also include an ornamental written, graphic, colored, and/or other suitable indicia or combination thereof on one or more of its surfaces to denote a “loaded chamber” condition.
According to another aspect of the preferred embodiment, the pistol includes a bolt that is slidably mounted in the barrel-receiver assembly. The bolt is preferably slidable in a forward direction towards the front of the pistol and in a rearward direction towards the rear of the pistol, as further described below. In one embodiment, the bolt has a recess configured and arranged to receive the indicating element. In another embodiment, the barrel-receiver assembly similarly has a cutout configured and arranged to receive the indicating element.
As the terms are used herein, the “front” of a pistol is defined as the barrel end and the “rear” of a pistol is defined as the handle or grip end of a pistol. Also as the terms may be used herein with respect to orientation using the pistol as a frame of reference to direction, “forward” indicates a direction towards the muzzle (front of barrel) end of the pistol and “rearward” indicates a direction towards the handle or grip end of the pistol. “Downwards” indicates a direction towards the bottom or underside of the pistol and “upwards” indicates a direction towards the top of the pistol 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 the preferred embodiment and is not intended in any way to limit the scope of the present invention thereto.
According to another aspect of the preferred embodiment, a biasing member, such as a spring, may be provided in one embodiment which is associated with the loaded chamber indicating element. The spring may be disposed in the barrel-receiver assembly and interacts with the indicating element to preferably bias the indicating element towards the first position described above (i.e., absence of a fully-loaded cartridge in the chamber). In one embodiment, the biasing member may be a helical spring.
A method of indicating a loaded pistol chamber is also provided including locating the rim of a cartridge on a continuous circumferential seat and displacing an element to a loaded-condition-indication position with the rim of the cartridge. In one embodiment, the method further includes protruding at least a portion of the indicating element outwards from an exterior surface of the pistol to provide a user of the pistol with a visual and tactile indication that a cartridge is loaded in the chamber. In yet another embodiment, the method includes the step of retracting the indicating element inside the pistol to an unloaded-chamber-indication position in the absence of contact between the indicating element and cartridge rim.
Although the preferred embodiment of a magazine disconnect mechanism will be described for convenience with reference to a pistol having a receiver that is fixed on the grip frame, and a bolt that is slidably movable within the receiver in response to recoil forces developed during firing, the invention is not limited in its applicability by such reference. Accordingly, the preferred embodiment may also be used in pistols having a movable bolt in the form of a slide that is slidably mounted on the grip frame to move in response to the recoil forces developed during firing. Although the preferred embodiment of a loaded chamber indicator is particularly suited for use with pistols that utilize rimfire-type ammunition, the preferred embodiment may be beneficially used in centerfire cartridge-type pistol applications as well.
The features of the preferred embodiments will be described with reference to the following drawings where like elements are labeled similarly, and in which:
Referring generally to
Pistol 1 includes a longitudinally-extending barrel 2 with longitudinal bore 5 therethrough and a generally hollow-structured receiver 4 in operational relationship with barrel 2. In a preferred embodiment, receiver 4 is disposed adjacent to and preferably attached to barrel 2; the combination defining a barrel-receiver assembly 3. Receiver 4 has an exterior surface 80 and an interior surface 82 defining a cavity 86 therein (see, e.g.,
Barrel 2 defines a longitudinal axis “LA” for pistol 1 passing through barrel bore 5. A transverse axis “TA” is defined perpendicular to the longitudinal axis LA. The barrel-receiver assembly 3 is preferably mounted to a grip frame 6 that includes a grip frame handle portion 15, which in one embodiment may hold a removable magazine (not shown) capable of holding and dispensing a plurality of cartridges. Pistol 1 further includes a trigger 8 for discharging the pistol.
A chamber block 70 associated and in operable relationship with barrel-receiver assembly 3 may be provided adjacent to the rear of the barrel 2. Chamber block 70 may be integral with barrel 2 or a separate component attached to barrel 2. Chamber block 70 preferably includes a chamber 11 which in the preferred embodiment may be a cylindrical bore. Chamber 11 is positioned and arranged to receive and hold a cartridge 50 which may include a cartridge casing 52 and an annular laterally-protruding rim 54 disposed around the rear or base 58 of the cartridge (best seen in
Chamber 11 defines a longitudinal chamber centerline 84 which coincides with longitudinal axis LA of the pistol and in which chamber centerline 84 is concentrically aligned with bore 5 of barrel 2. Chamber 11 preferably communicates with both bore 5 of barrel 2 to its front, and interior receiver cavity 86 to its rear to permit a cartridge to be loaded and chambered from the magazine into chamber 11, and ultimately discharged from pistol 1 through barrel 2. Accordingly, chamber 11 functions to hold cartridge 50 in preparation for discharging pistol 1.
In one embodiment, chamber block 70 may further includes sidewalls 76 and a rear surface 72. In a rimfire cartridge 50, rim 54 protrudes radially outwards beyond cartridge casing 52 (see
In one embodiment (as best seen in
A spring-biased hook-like extractor 81 may be provided which removes a spent cartridge casing from chamber 11 by grasping the cartridge rim 54 after pistol 1 is discharged. The spent casing is subsequently ejected from pistol 1. A small extractor notch 79 (best seen in
It will be appreciated that in an embodiment of pistol 1 intended to be used with centerfire cartridges (not shown), it is contemplated that cutout(s) may be made in circumferential seat 74 and/or sidewall 76 of chamber block 70. Centerfire cartridges have a deformable primer cup located in the center of the rear or bottom of the casing. The firing pin in a centerfire pistol is therefore positioned to strike the rear center of the cartridge at the primer cup. Accordingly, centerfire casings are typically strong in contrast to relatively fragile rimfire cartridges and do not require substantial support of the casing.
Chamber block 70 may have any suitable overall size and three-dimensional shape (e.g., square or rectangular block, cylindrical, etc.) so long as the chamber block is capable of housing a chamber 11 disposed therein.
Receiver 4 may further have a cartridge loading opening 17 as shown in
Pistol 1 further includes a firing pin 36 to strike the cartridge and discharge the pistol. Firing pin 36 has a longitudinally reciprocating forward and rearward motion and is mechanically actuated by trigger 8 (eventually) through various intermediate operable linkages. In the case of a rimfire cartridge, the rear of rim 54 must be struck and deformed by firing pin 36 (best seen
Referring now also to
The rear of bolt 7 may further have ears 40 as shown to allow a user to readily grip and manually retract the bolt.
With further reference to
As shown in
It will be appreciated that other mounting positions of indicating element 10 are possible so long as indicating element 10 is mounted close enough to chamber 11 such that at least a portion of indicating element 10 may come into operable contact with and be displaceable by cartridge 50 when the cartridge is loaded in the chamber.
Additional reference is now made to
As shown, indicating element 10 may include a substantially planar or flat body portion 25 having an overall width W and overall length L, a top surface 16, a bottom surface 18, and at least two longitudinally-extending sides 24, 34 connecting the top and bottom surfaces thereby defining a thickness 21 for indicating element 10. Preferably, side 24 may be substantially flat and faces towards the exterior of pistol 1 in one embodiment. Opposite side 34 may be irregularly-shaped for reasons described below. Indicating element 10 and side 24 are preferably configured as shown such that indicating element 10 will not protrude substantially beyond the exterior of the barrel-receiver assembly 3 when indicating element is in the first position (i.e., cartridge not fully-loaded into chamber 11) described above. It will be appreciated, however, that in some embodiments indicating element 10 may protrude slightly beyond the exterior of barrel-receiver assembly 3. Also preferably, the other side 34 faces towards chamber 11 and is configured to contact cartridge 50 when the cartridge is loaded into the chamber.
Indicating element 10 preferably may be generally elongate in shape and have two ends 12, 14. In one embodiment, indicating element 10 also preferably includes a broadened and laterally projecting portion 26 adjacent to body portion 25. Broadened portion 26 is preferably located between ends 12, 14 approximately near the middle of length L of indicating element 10. In one embodiment, broadened portion 26 may be configured to contact cartridge 50 and may be substantially planar.
In one embodiment, laterally projecting and broadened portion 26 may be flanged such that its thickness 23 is thinner than the thickness 21 of body portion 25 (best seen in
Preferably, indicating element 10 in one embodiment may be substantially rigid in structure. Preferably, indicating element 10 may made of any type steel; however, other suitable metallic (e.g., aluminum, titanium, etc.) and non-metallic materials (e.g., plastics) that are rigid may be used. In the preferred embodiment, indicating element 10 is made of steel.
With continuing reference to
Indicating element 10 may further preferably include a sensor surface such as cartridge contact surface 28 which is configured and located on element 10 to physically and operably contact cartridge 50 when loaded into chamber 11. Preferably, cartridge contact sensor surface 28 is located on indicating element 10 such that it may be operably contacted by side 56 of cartridge rim 54. Contact sensor surface 28 may be located on broadened portion 26 of indicating element 10. In one embodiment, contact surface 28 may be a cam having a generally arcuate or curved shape to come into gradual and smooth engagement with cartridge rim 54 when loaded into chamber 11; however, other suitable shapes may be used and are contemplated so long as cartridge 50 is able to physically deflect indicating element 10 by contact. Contact surface 28 may also include a chamfer 77 on its underside (see, e.g.,
Preferably, contact surface 28 is an integral part of indicating element 10 and more preferably of portion 26. However, contact surface 28 may be a separate component connected to indicating element 10. In an embodiment of an indicating element 10 having a flanged portion 26 as described above, cartridge contact surface 28 may preferably be disposed on flanged portion 26. The functioning of contact surface 28 will be discussed below.
As best shown in
A biasing member may be provided which is in operable relationship with loaded chamber indicating element 10. In one embodiment, the biasing member is a helical spring 38 as shown. Spring 38 may be disposed in the barrel-receiver assembly 3 and interacts with indicating element 10 to preferably bias the indicating element towards the first position described above and shown in
Operation of the loaded chamber indicator mechanism in conjunction with loading a cartridge into the chamber of a pistol will now be described with reference to the preferred embodiment described herein.
As cartridge 50 continues to be loaded forward into chamber 11 by bolt 7, the side 56 of rim 54 eventually contacts and engages indicating element 10, preferably at cartridge contact sensor surface 28 of side 34 of indicating element 10. Rim 54 activates and physically displaces indicating element 10, causing indicating element 10 to pivotally move about pivot point P. Indicating element 10 comes to a second and fully-activated position as shown in
Pistol 1 is normally discharged when trigger 8 is pulled, thereby causing firing pin 36 to strike the rear of cartridge rim 54. As shown in the figures (particularly
It should be noted that pin 29, and thus pivot point P, may be located in a number of suitable positions along the length L (see
To accommodate and receive indicating element 10, the barrel-receiver assembly 3 preferably includes a-cutout 30 (best seen in
As shown in
Bolt recess 42 includes an upper cavity 41, lower cavity 43, and a step 45 between upper and lower cavities 41, 43. Preferably, step 45 may be inclined or ramped as shown. In one embodiment as shown, lower cavity 43 and upper cavity 45 are preferably contiguous and form a common space to accommodate indicating element 10. Also as shown, upper cavity 41 preferably is deeper extending farther radially inwards towards the center of bolt 7 than lower cavity 43. Accordingly, in a preferred embodiment, the volume of upper cavity 41 is larger than that of lower cavity 43.
The forward or bolt stop surface 47 of bolt 7 (typically made of steel) preferably may be surface work hardened during the manufacturing process. This toughens bolt stop surface 47 to withstand forces imparted by bolt 7 striking the rear surface 72 of chamber block 70, thereby minimizing the possibility of structural fractures. Interior portions of bolt 7, however, are not hardened and less resistant to such impact forces. Accordingly, bolt recess 42 preferably may be stepped in shape as shown to minimize the amount of undercutting required and concomitantly maximize the strength of bolt 7. Thus, indicating element 10 is preferably cooperatively shaped with bolt recess 42 and in the preferred embodiment may have a stepped configuration also (as best shown in
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, sizes, 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, 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 not limited to the foregoing description or embodiments.