Patent Application
20170089664
The present disclosure relates to air guns, and more particularly, to an air gun having multiple energy sources for providing a compressed air charge for firing of a projectile from the air gun.
Compressed air powered guns or “air guns” utilize a compressed air charged to fire a projectile, such as a pellet, steel “bb” or dart. The projectile is loaded into a projectile chamber that is adjacent to or part of the air gun barrel. To fire the air gun, a compressed air charge is directed through a transfer port and into the projectile chamber. The air charge propels the projectile forward through and out of the muzzle end of the barrel toward a target.
Conventional air guns may include a mechanism to create the compressed air charge that is delivered to the projectile chamber for projectile firing. By way of example, some air guns include a piston that is movable in an air cylinder to provide the compressed air charge. Before firing, the piston is held in a cocked position against the force of an energized mechanical spring or gas strut. Upon firing, the piston is released and the mechanical spring or gas strut drives the piston through the air cylinder, compressing and delivering air from the cylinder and to the projectile chamber through the transfer port. After firing, a lever or other type cocking mechanism may be used to move the piston back to the cocked position for subsequent firing.
Other conventional types of air guns may use a compressed air charge that is held in a compressed air tank prior to firing of the air gun. When such air guns are fired (i.e., the trigger is released) fluid communication is opened between the compressed air tank and the projectile chamber to allow the release of compressed air and firing of a projectile. Such tanks may be sized to hold enough compressed air, or other propellant, to enable firing of multiple projectiles before the tank is refilled with compressed air. Some conventional air guns, often referred to as “pre-charged pneumatic” or “PCP” type air guns use compressed air tanks that are refilled by an external pump or a larger compressed air source, such as a SCUBA tank, to provide compressed air. Other conventional air guns may use a replaceable carbon dioxide charged cartridge to provide compressed gas for projectile firing.
According to a first example embodiment, an air gun is disclosed. The air gun includes a barrel including a projectile chamber configured to receive a projectile. A transfer port is in fluid communication with the projectile chamber of the barrel and is constructed and arranged to deliver a compressed air charge to the projectile chamber to fire the projectile from the barrel of the air gun. The air gun has a cocking mechanism. A first energy source is movable to a cocked position by actuation of the cocking mechanism. The first energy source is constructed and arranged to provide at least a portion of the energy that provides the compressed air charge when released from the cocked position. A second energy source selectively provides at least another portion of the energy for further compressing the air charge to fire the projectile. In some cases, the second energy source is configured to be charged by a source external to the air gun. In some cases, the second energy source is a carbon dioxide cartridge or a compressed air cartridge. In some cases, the second energy source is a compressed gas tank. In some cases, the second energy source is sized for multiple shots by the air gun. In some cases, the first energy source includes a piston that is movable to the cocked position by actuation of the cocking mechanism. In some cases, the first energy source includes a gas strut configured to drive the piston for providing at least the portion of the energy for compressing the air charge when the first energy source is released from the cocked position. In some cases, the first energy source includes a mechanical spring configured to drive the piston for providing at least the portion of the energy for compressing the air charge when the first energy source is released from the cocked position. In some cases, the piston includes a cavity configured to house a granulated material that acts as a rebound buffer when the air gun is fired. In some cases, the piston includes a rounded face that conforms to a corresponding feature of the air gun for promoting delivery of the compressed air charge to the projectile chamber. In some cases, the air gun includes a grooved surface on one of the piston and the corresponding feature of the air gun for providing delivery of compressed air to the transfer port. In some cases, the air gun is configured to be operable in at least two different firing modes, including: a first firing mode where the energy used to compress the air charge includes energy provided by only the first energy source; and a second firing mode where the energy used to compress the air charge includes energy provided by the first energy source and the second energy source. In some cases, the cocking mechanism is configured to be actuated by at least one of breaking a breach of the air gun, a side lever, and an under lever. In some cases, the barrel and the projectile chamber are constructed and arranged to receive and fire a pellet. In some cases, the barrel and the projectile chamber are constructed and arranged to receive and fire a dart.
According to another example embodiment, an air gun includes a barrel having a projectile chamber configured to receive a projectile. A transfer port is in fluid communication with the projectile chamber of the barrel and is constructed and arranged to deliver a compressed air charge to the projectile chamber to fire the projectile from the barrel of the air gun. A cylinder includes a piston and is in fluid communication with the transfer port and projectile chamber. The piston is constructed and arranged to move through the cylinder to compress air for delivery to the transfer port and projectile chamber as the compressed air charge. The piston includes a forward face having a rounded surface that conforms to a corresponding cylinder surface of the cylinder to promote delivery of the compressed air charge to the transfer port. In some cases, at least one of the rounded surface and the corresponding surface is at least partially constructed of a conformable material. In such cases, the piston includes an elastomeric end portion with the rounded surfaced being formed in the elastomeric end portion. In some cases, the rounded surface includes a convex surface that conforms to a corresponding concave surface of the cylinder. In some cases, the piston and cylinder are constructed and arranged such that contact is initiated at an outer radial portion of the forward face as the forward face contacts the corresponding cylinder surface. In some cases, at least one of the forward face of the piston and the corresponding cylinder surface includes one or more grooves that are constructed and arranged to direct compressed air toward the transfer port. In some cases, the piston includes a cavity configured to house a granulated material that acts as a rebound buffer when the air gun firearm is fired.
The present disclosure is not intended to be limited to a system or method that must satisfy one or more of any stated objects or features. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present disclosure.
In the drawings, different embodiments of the invention are illustrated in which:
Air guns conventionally include a barrel and a projectile chamber located at a proximal end, or near a proximal end, of the barrel. The projectile chamber receives a projectile, such as a pellet, bb, or dart, that is propelled from a muzzle end of the barrel by an air charge when an operator fires the air gun. The propulsion may be accomplished by delivering the air charge from an air source, through a transfer port, and into the projectile chamber.
Air guns are conventionally constructed with a single energy source that provides compressed air for projectile firing. The applicant has appreciated that different types of energy sources provide various benefits. For example, air guns that utilize pre-charged pneumatic air tanks as an energy source may be fired repeatedly in a convenient manner, while the air tank contains adequate propellant. The same is true of air guns that use compressed carbon dioxide cartridges as an energy source. On the other hand, cartridges and tanks are not needed for air guns that use an air cylinder with a piston that is released from a cocked position during firing. The applicant has appreciated that combining multiple types of energy sources into a single air gun can leverage the advantages and benefits of each type of energy source.
According to some example embodiments, an air gun includes an air cylinder, a piston disposed within the air cylinder, and a barrel in fluid communication with the air cylinder. The piston moves through the air cylinder to compress air within the air cylinder during the firing process. The compressed air, in turn, is ejected into the barrel for propelling a projectile. The air gun includes two different types of energy sources for propelling the piston. A first type of energy source may include, for example, a compressed mechanical spring coupled to the piston or a gas strut such as used in conventional piston air guns. A second type of energy source may be selectively applied to the piston in conjunction with the first type of energy source, and may include, for example, a compressed gas storage tank that holds compressed air, or another propellant stored in a compressed or liquefied state. Upon firing, the compressed gas is released to move the piston that, in addition to the first energy source, compresses air that is used to fire the projectile. The gas storage tank may be removed and replaced to replenish the supply of compressed gas. Alternatively, the gas storage tank may be recharged with compressed gas by an external pump or charging tank.
Air guns, according to some example embodiments, can have multiple firing modes. A user can select which firing mode to use for any given shot. In a first firing mode, energy to provide a compressed air charge may, for example, be drawn solely from a mechanical spring or gas strut that energizes a cocked air cylinder, which is moved by force of a compressed spring. In a second mode, energy to provide the compressed air charge may, for example, be drawn from both the mechanical spring or gas strut and by a force provided by compressed gas received from a compressed gas storage tank. An operator may choose to fire an air gun in the second mode to draw energy from multiple sources when additional firing power is desired, such as when hunting game. The first mode may be selected when a lower energy shot is desired as well as to conserve compressed gas in the gas storage tank, such as during target shooting or plinking. Air guns, according to other example embodiments, may additionally or alternatively include one or more other firing modes, as will be appreciated in view of the present disclosure.
A dual energy source air gun, according to some embodiments, can deliver shots with more energy than from the amount of energy an operator applies to cock the air gun between shots alone. During cocking, the piston of an air cylinder-type air gun is moved against a mechanical spring or gas strut, which stores energy that is later released during firing. The amount of energy that can be stored by cocking the gun is often limited by the strength and endurance of the operator. By contrast, in accordance with various embodiments, a dual energy source air gun having a second, supplemental energy source that is independent of the cocking action between shots enables the air gun to achieve higher muzzle energy shots for the same amount of energy that an operator exerts to cock the gun.
Various example embodiments of air guns may also include features that promote efficient delivery of compressed air to a transfer port and projectile chamber, during firing. As will be appreciated, greater power can be achieved by an air gun with a more complete and/or efficient delivery of compressed air to the projectile during firing. The applicant has also appreciated that if and when the piston rebounds against the end of the air cylinder near the end of the firing cycle, a portion of the air charge in the gun barrel may be drawn back into the air cylinder, which can undesirably reduce the pressure of the air propelling the projectile. If the projectile has not already exited the muzzle end of the gun barrel, this reduced pressure may slow or otherwise disrupt the projectile. To this end, and in accordance with some embodiments, the air gun includes a piston having a cavity that houses weighted, granulated material that acts as a rebound buffer when the piston contacts the end face of the air cylinder, which minimizes or prevents rebound of the piston.
Example embodiments may, additionally or alternatively, reduce or prevent piston rebound with features that redirect forces resulting from piston contact with the end face of the cylinder wall. For example, the forward face of the piston, and the mating end face of the cylinder wall, may each include surfaces that are oriented at an angle with respect to the direction of motion of the piston. In this respect, at least a portion of any force that results from contact between the piston and cylinder end wall is directed perpendicular to the direction of motion of the piston. The surfaces may, in some cases, additionally be symmetrical about an axis in line with the direction of motion of the piston, such that forces resulting from contact between piston and end face of the cylinder act to balance or cancel one another, thus reducing or preventing rebound of the piston.
The forward face of the piston, and an opposing face of an end wall of the cylinder, can include features that direct compressed air to the transfer port in a controlled manner. According to some example embodiments, contact between the piston and end wall may begin at points further from the transfer port in the end wall and progress toward the transfer port, with advancement of the piston to the wall. In this respect, the progression of contact may prevent the formation of compressed air pockets between the piston and end wall, further promoting efficient and/or complete delivery of the compressed air charge to the transfer port. Additionally or alternatively, one or both of the forward faces of the piston and the end wall of the cylinder can include grooves that receive and promote movement of the compressed air charge toward the discharge port.
Internal to the receiver 12 is a transfer port 30 that provides fluid communication between the air cylinder 20 and the projectile chamber 26. The transfer port 30 may, for example, have a small diameter (e.g., approximately 1/8 inch). The distal end of the piston 28 has an elastomeric end cap 34 with an integral seal 35. The gas strut 36 is configured to urge the piston toward an end face 32 of the air cylinder 20, adjacent to the transfer port 30. A vent port 38 on backside of the air cylinder 20 (i.e., the portion of the air cylinder behind the piston 28) provides fluid communication between the atmosphere and a volume inside the backside of piston 28 to allow venting of pressure / vacuum from the volume inside the backside of the piston 28 and to receive compressed gas into the volume inside the backside of the piston 28. The gas strut 36 is compressed by the cocking action, which forces the piston 28 rearward within the air cylinder 20. Likewise, the searing off action allows the gas strut 36 to move the piston 28 forward toward the end face 32 of the air cylinder 20, which creates a compressed air charge within the air cylinder 20. A supplemental propelling force can be selectively applied to the piston 28 by the compressed gas provided to the back of the piston 28 via the vent port 38. It will be understood that the air gun 10 can operate using the gas strut 36 alone or in combination with the supplemental compressed gas. It will be appreciated that
The set of valves also includes a manually actuated mode selector valve 42, according to the illustrated embodiment. The mode selector valve 42, when on, causes the air gun to draw compressed gas from a gas tank 46 to provide additional energy to move the piston 28 through the air cylinder 20 to provide a compressed air charge. When the mode selector valve 42 is off, fluid communication between the gas tank 46 and the port 38 of the air gun is closed throughout the firing cycle, such that the compressed air charge is formed solely from the movement of the piston 28 through the air cylinder 20 under potential energy of a gas strut 36 or mechanical spring. In the illustrated embodiment, the mode selector valve 42 includes a bi stable, lever operated valve, although other configurations may alternately be used. The gas tank may 46 include different types of compressed gas sources having the capacity to provide energy for multiple shots from the air gun, including but not limited to a replaceable, liquefied carbon dioxide cartridge and a rechargeable compressed air tank.
The set of valves further includes a gas tank valve 44 that may, for example, be cam (not shown) operated as the air gun moves through the firing cycle. When the mode selector 42 valve is open, the air tank valve 44 is actuated by a cam or other mechanism as the air gun is fired to release compressed gas from the gas tank to provide additional energy for propelling the piston 28 through the air cylinder. The additional energy helps generate greater pressures in shorter time in the compressed air charge, which is delivered through the transfer port 30 to the barrel 14 for firing a projectile. The gas tank valve 44 may also be opened during firing when the mode selector valve is closed, but in such instances the closed mode selector valve 42 will prevent compressed gas from escaping the gas tank and entering the volume inside the backside of the piston 28 through the vent port 38. In the illustrated embodiment the tank valve 44 is a normally closed, roller operated, spring return valve. Other types of valves such as a poppet type and actuating method like a hammer may alternately be used, as will be appreciated.
An example embodiment of the air gun 10 is shown at the initial stages of the cocking process in
Pulling the trigger of the air gun 10 causes the sear 50 to release the piston of the air cylinder, as shown in
When an operator desires to turn off the second energy source (e.g., tank of compressed gas), the manual selector valve 42 is moved to the closed position. The firing and cocking cycle shown in the progression of
In accordance with some embodiments, an interface between the piston 28 and the end face 32 of the air cylinder 20 may include features that promote a more complete and/or efficient delivery of compressed air to the projectile chamber through the transfer port 30. By way of example,
With some conventional air piston air guns, rebound forces during an impact between a flat faced piston and cylinder contact are predominantly axial, resulting in substantial rebound of the piston. This reverse movement of the piston creates a volume in the cylinder that is filled with a compressed air from a barrel, resulting in decrease of the air pressure propelling a pellet forward in the barrel. To this end, and in accordance with an embodiment of the present disclosure, an inclined contact surface of a forward face of a piston and a matching concave surface of an end face of a cylinder result in contact forces that lay on a substantial angle relative to the center axis of the cylinder, both of which have axial and radial components. Unlike the pure axial rebound forces in conventional air guns, the presence of radial forces leads to a decrease in the axial rebound energy. Additionally the collision forces normal to the contact surfaces result in friction between the piston end cap 34 and the end face 32 of the cylinder 20 and an additional wedging action that further dissipates the impact energy. This interaction of the piston and cylinder faces upon impact reduces or prevents piston rebound upon impact leading to improved efficiency of an air rifle in accordance with various embodiments.
The forward face 33 of the piston and/or the end face 32 of the air cylinder may be constructed of a material that prevents rebound. In the example embodiment of
The forward face of the piston 28 and the end face 32 of the air cylinder 20 may be constructed such that contact between these components acts to direct air towards the transfer port 30, according to some example embodiments. This can help prevent air pockets from occurring, promoting a more complete delivery of compressed air to the transfer port 30 and projectile chamber. In the example embodiment of
The piston of an air cylinder may, additionally or alternatively, include a granulated buffer material that moves with the piston, in a delayed manner, to buffer any rebound of the piston upon impact. According to one example embodiment (not shown) a piston includes a hollow cavity that encloses weighted and granulated buffer material. The material follows the piston toward the end face of the air cylinder and, at a time when the piston might experience rebound, contacts an interior wall of the cavity to counteract any rebound forces, thereby preventing rebound.
While several embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of this disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of this disclosure is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, along with other embodiments that may not be specifically described and claimed.
All definitions, as defined herein either explicitly or implicitly through use should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified, unless clearly indicated to the contrary.
This application claims the benefit of U.S. Provisional Patent Application 62/232,481, filed Sep. 25, 2015, and entitled “AIR GUN WITH MULTIPLE ENERGY SOURCES,” the entire disclosure of which is hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62232481 | Sep 2015 | US |
