Abstract:
An airgun has a pneumatic mechanism that is driven by an electrical motor to provide a blast of air, wherein the pneumatic mechanism is in a non-coaxial and angled position relative to the barrel, and wherein the air is delivered to the barrel via a preferably angled intermediate conduit. Spatial separation of the pneumatic mechanism from the axis of the barrel allows for substantially simplified constructions and use of light-weight material, and further provides a wide variety of handgun designs as the only space requirement for the projectile delivery portion is the barrel. Therefore, in one especially preferred aspect of the inventive subject matter, the airgun is configured a revolver.

Description:
FIELD OF THE INVENTION 
       [0001]    The field of the invention is motorized air guns, and especially motorized toy air guns. 
       BACKGROUND OF THE INVENTION 
       [0002]    Numerous airguns and toy airguns are known in the art, and most of such guns employ a reservoir of pre-compressed air or a manually tensioned spring mechanism to provide the motive force for the projectile. More recently, electric motors were implemented to provide at least some of the motive force, and typical examples for such motorized airguns are found in U.S. Pat. No. 4,899,717, U.S. Pat. No. 5,261,384, U.S. Pat. No. 6,564,788, JP6-235597, and JP2002-168594. However, and especially where such motorized airguns have relatively high muzzle velocities, several problems are encountered. 
         [0003]    For example, the compression chamber volume is often relatively large, thereby rendering the airgun bulky. Moreover, due to relatively strong springs and other associated parts, assembly is often complex and requires a plurality of hardened materials to withstand the strong forces and impact of components. Worse yet, as the compression springs in known motorized airguns are coaxially disposed relative to the barrel, recoil from unwinding of the spring and the impact of the plunger to its endpoint of movement makes accurate shooting difficult. Still further, due to the relatively bulky dimensions of coaxial compression chambers, handgun design is typically limited to relatively bulky gun bodies. 
         [0004]    Therefore, while there are numerous motorized airguns known in the art, all or almost all of them suffer from one or more disadvantages. Thus, there is still a need to provide improved motorized airguns. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to motorized airguns, and especially to motorized toy airguns. Most preferably, the barrel and the pneumatic mechanism in such guns are disposed in a non-coaxial and angled relation to each other to provide for simplified construction and allow for a wide design range. In preferred aspects, at least part of the pneumatic mechanism is disposed in the handle of the gun and an intermediate conduit delivers the air blast from the pneumatic mechanism to the barrel. 
         [0006]    In one aspect of the inventive subject matter, a motorized airgun includes an electric motor that is operatively coupled to a gear set, wherein the gear set has at least one drive gear and at least one output gear. A piston with a rack portion and a plunger portion is present in such guns, wherein the rack portion is coupled to a spring, wherein the plunger portion is disposed in a pneumatic cylinder, wherein the piston is configured to be movable between a first position and a second position, and wherein the output gear and the rack portion are configured to allow movement of the piston from the first to the second position. A barrel is typically fluidly coupled to the pneumatic cylinder, wherein the barrel has a longitudinal axis and the piston has a longitudinal axis, and wherein the longitudinal axis of the barrel and the longitudinal axis of the piston are in a non-coaxial and angled position relative to each other, and an intermediate conduit is configured to fluidly couple an opening of the pneumatic cylinder with one end of the barrel and further configured to transmit an air blast from the pneumatic cylinder to the one end of the barrel along a curved or angled path. 
         [0007]    Most typically, the airgun comprises a handle, wherein the motor and at least part of the gear set are disposed within the handle. Where desirable, at least part of the piston and at least part of the pneumatic cylinder may be disposed within the handle, and a power sources may be coupled to the gun (e.g., to the handle or barrel). In further preferred aspects, the opening of the pneumatic cylinder and the one end of the barrel are permanently open, and the intermediate conduit is configured such that the longitudinal axis of the barrel and the longitudinal axis of the piston have an angle of between 30 degrees and 80 degrees relative to each other. Typically, the piston has a first area that moves air from the pneumatic cylinder to the intermediate conduit, and wherein a cross section of the one end of the barrel has a second area, and wherein the second area is smaller than the first area. Furthermore, the piston and the pneumatic cylinder are preferably configured to allow movement of a gas volume of between 2 cm 3  and 10 cm 3  when the piston moves from the second to the first position. 
         [0008]    It is further generally preferred that the motorized airgun further comprises a trigger and an electronic control device that controls operation of the electric motor in response to actuation of the trigger. A retainer mechanism may be included that retains the piston in the second position, and the trigger may be configured to cooperate with the retainer mechanism to thereby release the piston from the second position upon actuation of the trigger. 
         [0009]    Therefore, and viewed from a different perspective, a motorized airgun may comprise an intermediate conduit that is fluidly coupled between a barrel and a pneumatic cylinder, wherein the intermediate conduit is configured to direct pressurized air from the pneumatic cylinder to the barrel at an angle that is substantially identical with an angle formed between the barrel and a longitudinal axis of a handle of the airgun. Preferably, the pneumatic cylinder is directly coupled to the intermediate conduit, wherein a piston is movably disposed within the pneumatic cylinder to provide a blast of air upon movement of the piston. It is further preferred that the piston is actuated via a rack gear and a transmission gear, and wherein the transmission gear is actuated by an electric motor. 
         [0010]    Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention. 
     
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0011]      FIG. 1A  depicts an exemplary motorized toy airgun. 
           [0012]      FIG. 1B  schematically illustrated the airgun of  FIG. 1A  in opened configuration. 
           [0013]      FIG. 2  is a schematic detail view of the motorized airgun of  FIG. 1  A. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    The inventor has discovered that a motorized airgun can be manufactured in a simple and effective manner that substantially improve performance and assembly while reducing cost. Most advantageously, the airguns contemplated herein comprise a barrel and a pneumatic cylinder that are in a non-coaxial and angled position relative to each other, wherein fluid coupling is achieved by an intermediate conduit. Such configuration not only allow spatial separation of the barrel from the pneumatic cylinder, but also eliminate recoil effects otherwise observed with airguns in which the springs and plunger are coaxially oriented relative to the barrel and trajectory of the projectile. 
         [0015]    One exemplary motorized airgun is depicted in  FIG. 1A  in which the airgun  100 A is configured as a revolver.  FIG. 1B  schematically illustrates the airgun of  FIG. 1A  in a opened configuration. Here, airgun  100 B has a plastic housing  102 B with a barrel portion  104 B and a handle portion  105 B. Within the handle portion  105 B is the electric motor  110 B, which is mechanically coupled to gear set  120 B. Pneumatic assembly  130 B (comprising among other elements pneumatic cylinder and piston) is actuated by the gear set  120 B and release of an air blast from the pneumatic cylinder is triggered by trigger assembly  132 B. The air blast is then routed to the barrel  150 B via the intermediate conduit  140 B. Battery  160 B provides electricity for the electric motor  110 B. In such configuration, pushing of the trigger actuates the trigger lever, resulting in formation of an electrical contact of the circuitry to thereby power the electric motor in the handle portion. As a consequence, the gear set will move the piston in the pneumatic assembly and produce a high pressure air blast, which then ejects the bullet out of the barrel. Most typically, the bullets are fed from a spring-loaded magazine in the handle portion in a position directly adjacent of the outlet of the intermediary conduit. In one relatively simple configuration, the sequence will continue for every pushing of the trigger. 
         [0016]      FIG. 2  schematically depicts an exemplary propulsion assembly that comprises electric motor  210  to which the gear set  220  is operatively coupled. Here, motor pinion  211  drives dual gear  221  and  222 , which in turn drives single gear  223  that turns transmission gear  224 . The transmission gear  224  has an inner continuous portion that engages with gear  223  and an outer teethed sector that engages with the rack gear on the rack portion  236  of the piston in the pneumatic assembly  230 . Here, counterclockwise actuation of the transmission gear  224  results in a downwards movement of the piston in the pneumatic cylinder  232 , which results in a downwards motion of the plunger portion  234 . Upon reaching the lower dead point, the piston is arrested by retainer mechanism  260  to maintain the gun in the cocked state. Spring  238  stores the kinetic energy provided by the motor. Trigger assembly (not shown) cooperates with the retainer mechanism  260  to unlock the piston from the cocked state and thereby deliver an air blast via unwinding of the spring  238 . 
         [0017]    The air exits the pneumatic cylinder  232  via an opening in the pneumatic cylinder and travels into the intermediate conduit  240  via corresponding opening  242 A. Intermediate conduit  240  has a second opening  242 B that delivers the air blast to the end of barrel  250 , which is fluidly coupled to the conduit  240 . Here, the intermediate conduit is configured such that the angle  270  that is formed between the longitudinal axis of the barrel and the longitudinal axis of the piston is approximately 70 degrees, which is substantially identical (i.e., ±5 degrees) with the angle of the longitudinal axis of the barrel relative to the longitudinal axis of the handle. It should be particularly appreciated that in preferred aspects of the inventive subject matter the recoil of the spring in the handle portion will only insignificantly affect the targeting. Moreover, as the upper dead point of the plunger need not sealingly engage with the opening in the pneumatic cylinder, an impact of the plunger with the cylinder wall is avoided and less resilient materials can be employed for construction. 
         [0018]    It is generally contemplated that the motorized airgun according to the inventive subject matter may be configured in numerous ways so long as the motorized airgun retains at least one barrel, the intermediate conduit and the motorized pneumatic assembly. For example, suitable airguns may be configured as multi-barrel machine guns, as futuristic looking weapons, as rifles, automatic handguns, etc. However, it is typically preferred that the airgun has the outward appearance of a revolver. To that end, all methods of manufacture are deemed suitable and preferably include formation of a divided and preformed (cast, injection molded, etc.) plastic shell into which the barrel and other components are inserted. Similarly, the barrel may be produced from various materials, but metallic materials are typically preferred. For example, especially preferred materials for the barrel include light-weight materials (e.g., predominantly comprising (&gt;50%) aluminum, metal reinforced fiberglass, etc.), while alternative materials include hard plastics and even glass. In preferred aspects, the barrel will extend throughout the entire length of the barrel portion and may have two or more grooves. 
         [0019]    Typically, the barrel will be coupled to a projectile feeding mechanism and the choice of feeding mechanism will typically depend at least in part on the particular projectile. Most preferably, the projectile is a small round plastic bullet or BB, but other projectiles are also deemed suitable. The projectile feeding mechanism may be coupled to either end of the barrel, and all known projectile feeding mechanisms are deemed suitable for use herein. For example, where the projectile feeding mechanism is coupled to the front end of the barrel, the projectile feeding mechanism may be configured and coupled to the barrel as described in U.S. Pat. No. 6,564,788, which is incorporated by reference herein. Similarly, and especially where only single projectiles are launched, the projectile may be manually and individually inserted to the front end of the barrel. On the other hand, where the projectile feeding mechanism is coupled to the back end of the barrel (e.g., between the barrel end and the intermediate conduit or directly to the intermediate conduit), as described in U.S. Pat. No. 5,261,384, incorporated by reference herein. Alternatively, the projectile may also be manually be inserted into the back end of the barrel as in U.S. Pat. No. 4,899,717, which is also incorporated by reference herein. 
         [0020]    With respect to the electric motor it should be appreciated that numerous electric motors are deemed suitable for use herein and suitable motors include simple DC motors as well stepper motors. Generally, the power requirements and/or output of the motor will determine the muzzle velocity to a large degree and a person of ordinary skill in the art will readily determine suitable motor parameters for a particular velocity. For example, where a relatively high muzzle velocity is desired, a high-torque electric motor may be selected and disposed in a separate housing (or butt of a rifle). On the other hand, where muzzle velocity is adapted for use of the gun as a toy gun, relatively small electric motors may be used. Where desirable, the motor will be disposed within the handle of the gun. However, alternative locations for the motor are also deemed suitable herein (e.g., in simulated magazine, body of the gun, or other compartment). Typically DC electric motors will operate at a voltage of between 3-9 Volt, which can commonly be provided by one or more batteries. Where the motor is a stepper motor, suitable circuitry must be included, which is well known in the art. In such case, the control circuitry is preferably set to cause a single and complete turn of the transmission gear. If a regular DC motor is used, suitable interrupt switches may be provided to achieve the same purpose (see e.g., U.S. Pat. No. 6,564,788). Most typically, the trigger and the retention mechanism will cooperate with the interrupt switches in the control of the electric motor. 
         [0021]    Depending on the location of the electric motor, the mechanical coupling of the motor with the gear set may vary considerably, and appropriate couplings include direct coupling via a motor pinion as depicted in  FIG. 2 , or an optionally flexible axle, and/or even hydraulic fluid. However, it is generally preferred that the coupling is mechanical, and especially via one or more gears. In especially suitable gear sets, high rotational velocity of the motor pinion is translated into high torque and low velocity of the rack gear. Alternatively, a high-output motor may also be employed with a gear that provides high torque and optionally fast velocity of the rack gear. Consequently, the gear set may vary considerably, and all known gear sets are deemed suitable for use herein. It should therefore be noted that the particular choice of gear set will predominantly depend on the location of the motor relative to the piston, the desired force translation, and speed of the piston. Most preferably, the piston is actuated via a rack gear and/or a hydraulic arrangement against a counteracting force. In particularly preferred aspects, the counteracting force comprises a spring that is compressed when the gear set is actuated by the electric motor. However, in other contemplated aspects, the counter active force need not be limited to a spring, but may also include other resilient members, including rubber bands, elastic deformation of a deforming member (which may or may not be part of the piston), etc. 
         [0022]    With respect to the piston, it is generally preferred that the piston is a continuous structure having a plunger portion and a rack portion. Depending on the particular type of pneumatic cylinder, the plunger and/or rack portion may include one or more gasket or other seal to provide desirable compression. Furthermore, the dimensions of the plunger portion and the piston portion will vary depending on numerous factors. For example, where high torque output is provided by the transmission gear, the rack portion may be relatively short. On the other hand, where the pneumatic cylinder is relatively tall and/or has a relatively small diameter, or where the motor is relatively weak, the rack portion may be relatively long. Preferred pistons will have a relatively large plunger area relative to the cross section of the barrel to provide a strong and/or voluminous blast with moderate plunger movement. Viewed from another perspective, the piston will have a first area that moves air from the pneumatic cylinder to the intermediate conduit, and wherein a cross section of the one end of the barrel (e.g., manufactured from a metal or hard plastic) has a second area, and wherein the second area is smaller than the first area. It is further generally preferred that the motor, and at least part of the gear set and/or piston are configured to be at least partially, and more preferably entirely disposed within the handle portion. Therefore, the pneumatic cylinder will also be at least partially disposed within the handle portion. Depending on the desired volume of the plunger stroke (i.e., volume of air per shot), the volume of the pneumatic cylinder may vary. However, it is generally preferred that the volume is between 1 and 20 cm 3 , more preferably between 2 and 10 cm 3 , and most preferably between 2 and 5 cm 3 . 
         [0023]    It is still further generally preferred (but not necessarily required) that the airgun includes a retaining mechanism that retains the piston in the cocked position. There are numerous retaining mechanisms known in the art (see e.g., U.S. Pat. No. 6,564,788 or 4,899,717), and all of such mechanisms are deemed suitable for use herein. However, it is typically preferred that the retainer mechanism releasably retains the piston in the cocked position, and that the trigger mechanism will interact with the piston and/or retainer mechanism to release the piston from the cocked position to the upper deadpoint of the plunger. In alternative aspects of the inventive subject matter, the retaining mechanism may also include an electromagnet that cooperates with a metallic or paramagnetic element on the piston (typically at the end of the rack portion). A trigger assembly may then be employed to release the piston from the cocked position. There are numerous trigger mechanisms known in the art and all of those are deemed suitable for use herein. Thus, trigger assemblies typically preferred for use in contemplated airguns will be mechanical triggers that cooperate with the retaining mechanism and/or the piston to thereby trigger the release of the piston from the cocked position. In further particularly preferred aspects, the trigger assembly will also be configured to include or be coupled to an electronic control device that controls operation of the electric motor in response to actuation of the trigger assembly. Therefore, pulling of the trigger will not only release the piston from the cocked position, but also provide an electrical signal/electricity to the motor to reposition the piston back into the cocked position via the gear set. Depending on the particular type of the motor and the configuration, the electronic control device may be relatively complex (e.g., includes electronics to drive stepper motor) or more simple (e.g., using a timer and/or interrupter to control on-time of the motor). The motor is typically driven by an optionally rechargeable battery (preferably coupled to or at least partially retained within the housing), but external power sources are also deemed suitable. 
         [0024]    With respect to the intermediate conduit it is preferred that the intermediate conduit has a fixed geometry with an input opening through which the air is received from the pneumatic cylinder and an output opening through which the air is delivered to the barrel. Most typically, the intermediate conduit is manufactured from plastic and is relatively rigid. However, in less preferred aspects, the intermediate conduit may also be flexible (e.g., in form of a tubing or hose). Regardless of the particular configuration of the intermediate conduit, it is contemplated that the conduit is configured to transmit an air blast from the pneumatic cylinder to one end of the barrel along a curved or angled path. Most typically, the curved or angled path will have substantially the same angle or curve (e.g., ±5 degrees) as the angle/curvature between the handle portion and the barrel portion of the airgun, and the opening of the pneumatic cylinder and the one end of the barrel are permanently open. For example, the longitudinal axis of the barrel and the longitudinal axis of the piston have an angle of between 30 degrees and 80 degrees relative to each other. While it is generally preferred that the pneumatic cylinder and the barrel are directly coupled to each other via the intermediate conduit, additional conduits may also be included. 
         [0025]    Typically, the volume of the intermediate conduit is smaller than the blast of air that is provided by the piston/pneumatic cylinder. For example, typical volumes for the intermediate conduit are between 0.1 to 0.5 times the blast volume, and less typically between 0.5-0.9 times the blast volume. In still further aspects, however, volumes of between about 0.9 and 1.5 times the blast volume are also contemplated. In additional aspects, and especially where the airgun is configured to provide multiple air blasts, the volume of the intermediate conduit may also be significantly larger than the blast of air. In such configurations, the intermediate conduit may act as a reservoir for compressed air (the motor may then operate continuously or may be stopped at a predetermined pressure in the conduit). For ease of manufacture, it is typically preferred that the gear set, the piston, and the intermediate conduit are manufactured from a plastic (e.g., polystyrene, polyethylene, polycarbonate, polyvinyl chloride, etc.). 
         [0026]    Thus, specific embodiments and applications of motorized airguns have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.