Patent Application
20080216640
The invention described herein may be manufactured, used, and/or licensed by or for the United States Government.
1. Field of the Invention
The invention generally relates to rammers used for artillery projectiles, and more particularly to a self-powered rammer for engaging artillery projectiles or propellant charges.
2. Description of the Related Art
Projectiles, and when separate from projectiles, the propellant charges, must be thrust far enough into the tube of an artillery piece for proper loading. In some instances, in order to properly load a projectile, man-powered rammers are used. In other instances, artillery with auxiliary power such as the South African G-5 may be used to power the rammers. The former Soviet 2A36 and 2A65 towed artillery pieces use a rammer. The rammer and breech of the 2A36 are operated from a hydraulic reservoir charged by recoil, but until the first shot, the rammer for the 2A36 is initially manually operated. The rammer for the 2A65 uses a spring assisted mechanism. However, these types of towed artillery pieces are extremely heavy, and may not be suitable for air transport.
Self-propelled artillery uses powered rammers which are hydraulically actuated. Typically, hydraulic power is used in order to satisfy the requirement for a very rapid exertion of force with a very high force at the same time that the actuating devices are moving at a high speed. Electric motors exert a maximum torque at zero speed with the torque falling off as the motor speed increases. This phenomenon is generally unavoidable due to the generation of counter electromagnetic forces caused by a turning motor as verified by Lenz' law. Internal combustion engines cannot cease to turn without stopping completely (stalling), which requires clutches or hydro-pumped transmissions to exert intermittent forces. However, these additional components tend to add extra weight and complexity to the system.
Furthermore, in the past, some heavy naval turret artillery used steam powered rammers. Here, steam from the ship's boilers was used to power the rammers. However, these components tended to be quite heavy and fuel intensive. Therefore, there remains a need for a lightweight self-propelled rammer which does not require heavy sub-components or power sources or laborious and slow manual pumping to propel the rammer for engaging an artillery projectile or propellant charge.
In view of the foregoing, an embodiment of the invention provides a rammer system and an artillery ramming assembly for engaging an artillery projectile or propellant charge, wherein the rammer system comprises an internal combustion generator comprising a first firing mechanism; an actuator driven by the firing mechanism, wherein the actuator comprises a propellant combustible or decomposable into a pressurized fluid; and a pressure accumulator connected to the actuator, wherein the pressure accumulator controllably releases the pressurized fluid; a ramming component connected to the internal combustion generator and powered by the pressurized fluid; and means for regenerating pressure in the pressure accumulator actuated by recoil motion of the ramming component.
According to the invention, the first firing mechanism comprises any of a catalyst, a spark-generating mechanism, and a percussion or electric initiation-firing pin or probe. In one embodiment, the actuator comprises a combustion chamber configured for allowing the propellant to combust upon actuation from the first firing mechanism; and a first rupture disc connected to the combustion chamber, wherein the actuator further comprises at least one hole configured in the actuator and positioned between the combustion chamber and the first rupture disc; a pressure reservoir adjacent to the first rupture disc; and a particulate filter adjacent to the pressure reservoir.
In an another embodiment, the actuator further comprises a pressure reservoir connected to the first rupture disc; a second rupture disc; a plurality of holes configured in the actuator and positioned between the pressure reservoir and the second rupture disc; and a pneumatic chamber adjacent to the second rupture disc. The actuator further comprises a slidably mounted closure wedge connected to the pneumatic chamber. Additionally, in one aspect of the invention, the actuator further comprises a particulate filter adjacent to the pneumatic chamber. In another aspect of the invention, the actuator comprises a combustion chamber configured for allowing the propellant to combust upon actuation from the first firing mechanism; a second firing mechanism; and a charge tube connecting the first firing mechanism to the second firing mechanism.
Moreover, the propellant comprises any of a solid propellant, a liquid propellant, a fluid propellant, and a combination thereof. Also, according to another embodiment, the propellant comprises a monopropellant mixture comprising a liquid monopropellant and a catalyst. The pressure accumulator comprises a first orifice connected to the actuator; a piston; a pressure release valve; a second orifice separated from the first orifice by the piston, wherein the second orifice being configured to have a height smaller than a height of the pressure accumulator; a tube portion connected to the second orifice; and a fluid release valve disposed in the tube portion. The system further comprises a particulate filter disposed in the tube portion.
Furthermore, the ramming component comprises a rammer chamber connected to the tube portion; a rammer piston enclosed in a portion of the rammer chamber; at least one bias member connecting the rammer piston to the rammer chamber; a pressure vent disposed in the rammer chamber; and an opening in the rammer chamber configured for allowing translation of the rammer piston therebetween, wherein the ramming component further comprises a seal configured in the opening and positioned proximate to the rammer piston. Additionally, the rammer piston comprises a generally elongated cylindrical shaft portion and a pair of generally cylindrical end portions positioned on opposite ends of the shaft portion.
Another embodiment of the invention provides an artillery ramming system comprising means for triggering combustion of a combustible propellant into a fluid; means for pressurizing the fluid; means for controlling a flow of the pressurized fluid; means, powered by the pressurized fluid, for ramming any of an artillery projectile and propellant charge; and means, actuated by recoil motion of the means for ramming, for regenerating pressure in the artillery ramming system.
Another aspect of the invention provides a method of ramming an artillery projectile or propellant charge, wherein the method comprises triggering combustion of a combustible propellant into a fluid; pressurizing the fluid in a pressure vessel; controlling a flow of the pressurized fluid in a pressure accumulator; ramming any of an artillery projectile and propellant charge using a rammer driven by power generated by the pressurized fluid; and regenerating pressure in the pressure accumulator using recoil motion of the rammer, wherein the triggering occurs using a firing mechanism comprising any of a catalyst, a spark-generating mechanism, and a percussion or electric initiation-firing pin or probe, wherein in the step of triggering, the combustible propellant comprises any of a solid propellant, a liquid propellant, a fluid propellant, and a combination thereof, and wherein the combustible propellant comprises a monopropellant mixture comprising a liquid monopropellant and a catalyst.
The embodiments of the invention provide a rammer system that is sufficiently lightweight to be dismountable and transported separately from other artillery pieces to save weight when sling loading, if necessary. Because there are no hydraulic reservoirs or motors on the rammer system, the rammer system could slip over studs on the carriage of a gun, perhaps engaging the recoil mass by a pad, could be removable, and could be lifted by as few as two crewmen. Other advantages afforded by the embodiments of the invention are increased speed, reduced fatigue, reduced heat stress when wearing chemical protective gear, especially overgarments, reduced personnel requirements, and increased safety.
These and other aspects of the embodiments of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments of the invention and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments of the invention without departing from the spirit thereof, and the embodiments of the invention include all such modifications.
The embodiments of the invention will be better understood from the following detailed description with reference to the drawings, in which:
a) is an isolated view of the actuator component of
b) is an isolated view of the actuator component of
c) is an isolated view of the actuator component of
d) is an isolated view of the actuator component of
e) is an isolated view of the actuator component of
The embodiments of the invention and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments of the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments of the invention may be practiced and to further enable those of skill in the art to practice the embodiments of the invention. Accordingly, the examples should not be construed as limiting the scope of the embodiments of the invention.
As previously mentioned, there remains a need for a lightweight self-powered rammer which does not require heavy sub-components or power sources or laborious and slow manual pumping to propel the rammer for engaging an artillery projectile or propellant charge (such as gunpowder). The embodiments of the invention achieve this by using a gas generator producing high pressure gas, which acts directly or through a floating piston on another piston that performs the motions of ramming the artillery. Referring now to the drawings, and more particularly to
According to the embodiments of the invention, the rammer system operates by use of a pressure accumulator 19 for the loading of each shot (illustrated in
The firing mechanism 5 engages a breech closure 12, which is preferably embodied as a horizontally guided sliding wedge. The breech closure 12 connects to a first side of an actuator component 14, wherein the actuator component 14 is embodied as a combustion chamber, a propellant cartridge, or a pressure vessel. The rammer system 1 includes a pressure accumulator 19 on a second side of the actuator component 14, wherein the pressure accumulator 19 generally includes buffered space 16 configured for allowing variable pressure inside the pressure accumulator 19. The pressure accumulator 19 is particularly useful for metering rapidly produced high pressure gas 60 (shown in
A piston 18, which may be embodied as a floating piston or a spring-loaded piston, is aligned in the pressure accumulator 19 to help drive the actuating fluid 22 located in the pressure accumulator 19. The gas 60 generated in the actuator component 14 and pressurized in the pressure accumulator 19 drives the piston 18, which then drives the actuating fluid 22 (best seen in
The actuating fluid 22 is driven from the pressure accumulator 19 through an opening leading to a tube 17, which is configured narrower than the pressure accumulator 19, thereby creating a zone of increased pressure within the tube 17 compared with the pressure accumulator 19. That is, the height of the tube 17 (and opening leading to the tube 17) is smaller than the height of the pressure accumulator 19.
The pressure in the tube 17 is further controlled by a valve 26 connected to the tube 17. The actuating fluid 22, upon exiting the end of the tube 17, enters a rammer chamber 15 and engages a rammer 28. The rammer 28 is generally configured in an elongated “H” or rotated “I” configuration, however those skilled in the art would readily understand incorporating any functional configuration for the rammer 28.
Preferably, the rammer 28 comprises a pair of generally upright cylindrical ends 38, 39 connected by a cylindrical rammer piston 35 therebetween. A first surface 11 of a first upright end 38 contacts the actuating fluid 22 which exits the tube 17. A second surface 13 of the first upright end 38, which is on an opposite side of the first upright end 38 from the first surface 11, engages a pair of bias elements 30 such as springs which could be further embodied as pneumatic recovery springs or hydro springs.
The bias elements 30 are positioned between the second surface 13 of the first upright end 38 of the rammer 28 and the back wall 9 of the rammer chamber 15. The rammer chamber 15 further comprises a vent 23 connecting to a valve 32 to help release accumulated pressure within the rammer chamber 15 caused by the pressure exerted on the rammer 28 by the actuating fluid 22. However, the vent 23 is not utilized or is not configured in the rammer chamber 15 at all if the bias elements 30 are embodied as pneumatic recovery springs or hydro springs.
An opening is configured in the outer casing 24 of the rammer chamber 15 configured for allowing the rammer piston 35 to translate back and forth. Additionally, dust seals 8 are positioned on the back end 7 of the rammer chamber 15 such that the dust seals 8 are configured around the rammer piston 35. Moreover, a portion of the rammer piston 35 along with the second upright end 39 of the rammer 28 is located outside the rammer chamber 15. The second upright end 39 engages an artillery projectile or propellant charge 34 set on a loading tray 36.
The firing mechanism 5 connects to a breech closure 12, which is preferably embodied as a horizontally guided sliding wedge. The breech closure 12 connects to a first side of an actuator component 14 embodied as a combustion chamber, a propellant cartridge, or a pressure vessel. On a second side of the actuator component 14 the rammer assembly 10 includes a pressure accumulator 19 which holds the actuating fluid 22. A vent 21 connecting to a valve 20 is connected to the pressure accumulator 19 to help release accumulated pressure (caused by actuation of the actuating fluid 22 upon firing of the firing mechanism 5) within the pressure accumulator 19.
The actuating fluid 22 which may be embodied as a propellant gas is located in the pressure accumulator 19. The actuating fluid 22 is driven from the pressure accumulator 19 and into a tube 17, which is configured narrower than the pressure accumulator 19, thereby creating a zone of increased pressure within the tube 17 compared with the pressure accumulator 19. One difference between the open cycle rammer assembly 10 shown in
The pressure in the tube 17 is further controlled by a valve 26 connected to the tube 17. The actuating fluid 22 upon exiting the end of the tube 17 enters the rammer chamber 15 and engages a rammer 28. The remaining components of rammer assembly 10 are identical to similar components in rammer system 1 as described above.
The regeneration cylinder 42 further comprises an inner chamber 43 that houses a regeneration piston 48. The regeneration piston 48 is generally “T” shaped, although any functional configuration could be used. Preferably, the regeneration piston 48 is configured with a generally upright cylindrical end 46, which comprises a first surface 51 and a second surface 49, which is on an opposite side of the upright cylindrical end 46 from the first surface 51. The second surface 49 engages a pair of bias elements 47 such as springs which could be further embodied as pneumatic recovery springs or hydro springs. The bias elements 47 are positioned between the second surface 49 of the upright cylindrical end 46 and the inner back wall 52 of the regeneration cylinder 42. Furthermore, a regeneration cylinder entry tube 44 comprising a valve 45 is positioned between the regeneration cylinder 42 and the rammer chamber 15.
Next, as illustrated in
Then, as depicted in
a) through 8(e) illustrate various embodiments of the actuator component 14, wherein reference to like numerals correspond to like elements. According to a first embodiment illustrated in
Furthermore, configured in the casing 140 opposite the front wall 143 is a plurality of holes 148, which lead to a perforated disc 150 to retain a high pressure to provide for stable burning of the solid propellant 141. The holes 148 may also be embodied as a porous material. The perforated disc 150 may be a rupture disc and can be configured in any geometry that retains gas pressure but that also allows for free venting of reduced pressure gas. A pressure reservoir 153 is positioned adjacent to the perforated disc 150, which then connects to a particulate filter 152 that connects to a portion of the casing 140.
In a second embodiment shown in
c) illustrates a third embodiment of the actuator component 14. Structurally, the third embodiment is similar to the second embodiment except that in lieu of a particulate filter 162 as provided in the second embodiment, the third embodiment includes a slidably mounted closure wedge 164 serving as a mechanical membrane barrier for the actuator component 14 to prevent dirt from entering the actuator component 14. Another difference between the third embodiment and the second embodiment is that in the third embodiment the propellant is a monopropellant mixture 147 comprising a liquid monopropellant such as hydrogen peroxide or hydrazine plus a decomposition catalyst. The monopropellant mixture 147 (liquid monopropellant and catalyst) are separated by barrier capsules 165 ruptured by the pressure of the firing mechanism 5.
The geometry of the monopropellant mixture 147 is dependent on the choice of materials. For example, H2O2 may be confined in a barrier capsule 165 next to the firing mechanism 5. Once the firing mechanism 5 ruptures the barrier capsule 165, the H2O2 floods the combustion chamber 142 comprising granulated manganese dioxide or potassium permanganate. The concentrated H2O2 then decomposes into steam. Thereafter, the rupture disc 154 breaks allowing the gas to flood the pressure reservoir 156.
In a fourth embodiment, as illustrated in
Thus, in the example above the gas generating material may include a solid propellant mixed with a first capsule or microbead 166 comprising a phase change material such as water or fuel such as hydrocarbon or plastic, and is mixed with a second capsule or microbead 167 comprising an oxidizer. In the latter case, the goal is deflagration (burning) rather than detonation, which is an explosive process involving a shock wave. If an engine detonates (pings) it loses power, whereas steady burning produces the most power. The pressurizing fluid passes through the rupture disc 154 by rupturing it, and by going through the closure wedge 164 because the wedge material is porous with hole sizes too small for dirt.
According to a fifth embodiment, the actuator component 14, as shown in
During operation, the gun crew inserts an initializing actuator component 14 such as a gas generating cartridge into position and closes the breech closure 12. The actuator component 14 may comprise black powder, smokeless powder, a gas generating compound such as solid rocket fuel, a monopropellant such as hydrazine or hydrogen peroxide, or even compressed gas. If any combustible gas generating material is included in the actuator component 14, then the gas generating material is ignited by a percussion or electrical squib using the firing mechanism 5. If the actuator component 14 includes a monopropellant, then the monopropellant is released onto a catalyzing bed by a squib activated perforated disc 150 (shown in
When the crew is ready to ram the projectile or propellant charge 34 they place the projectile or propellant charge 34 in the loading tray 36 by mechanical or manual means, and then open the valve 26 from the pressure accumulator 19 to the rammer chamber 15, allowing the actuating fluid 22 to compress the rammer piston 35, which pushes the projectile or propellant charge 34 into the gun/cannon chamber (not shown).
Once the projectile or propellant charge 34 is properly seated, the rammer piston 35 retracts. The retracting rammer piston 35 pushes the actuating fluid 22 out of the rammer chamber 15 which further actuates the rammer piston 35. The actuating fluid 22 may be vented to atmosphere or vented to the regeneration cylinder 42 as shown in
If the round is separately loaded, the projectile or propellant charge 34 is placed in the loading tray 36 and the actuating fluid 22 is allowed to act on the rammer piston 35 again, ramming the projectile or propellant charge 34 into the chamber (not shown). The rammer piston 35 is retracted and the gun breech (not shown) is closed. When ready, the crew fires the gun/cannon (not shown), which recoils within its cradle shown as recoil mass 50. The recoil motion may actuate the regeneration piston 48 to compress the actuating fluid 22 back into the pressure accumulator 19 (regeneration) as shown in
The triggering (201) occurs using a firing mechanism 5 comprising any of a catalyst, spark-generating mechanism, and a percussion or electric initiation-firing pin or probe. Additionally, the combustible propellant comprises any of a solid propellant 141, a liquid propellant 145, a gas propellant 151, and a combination thereof (hybrid propellant) 149. Alternatively, the combustible propellant comprises a monopropellant mixture 147 comprising a liquid monopropellant and a catalyst.
Generally, the invention uses a gas generator component 2 configured for powering a ramming component 3 of an artillery rammer system 1. More specifically, the gas generator component 2 produces a source of high pressure gas, which may, if desired, act through a pressure accumulator 19 on a rammer 28 to effectuate the ramming sequence. For gas generator grains that produce debris, particulate filters 37 may be incorporated if needed. The gas generator component 2 may use either pyrotechnics or propellants 141, 145, 149, or produce either gas (gas propellant 151) alone or gas and steam through the decomposition of a monopropellant mixture 147 such as hydrogen peroxide or hydrazine.
Moreover, gas generation by artillery propellants 141, 145, 147, 149, 151 require high pressure for stable burning. The required pressure can be attained for small quantities of propellant 141, 145, 147, 149, 151 through use of the high-low process. In this process, used for example in a 40 mm grenade launcher, a quantity of propellant 141, 145, 147, 149, 151 is burned in a low volume, thick walled actuator component 14, which is vented through a small hole 148 that is closed by a rupture or perforated disc 150. The perforated disc 150 breaks and vents the gases once the proper pressure has been reached.
Several embodiments for the lightweight actuator component 14 exist. The propellants can be either single, double, or triple base solid propellants 141, or liquid propellants 145 being developed for the next generation of artillery systems. The liquid propellant systems use materials such as HAN (hydroxyl ammonium nitrate in water).
According to the embodiments of the invention, the rammer system 1 includes lightweight components actuated by gases produced by a pyrotechnic device such as a cake of a grain of propellant 141, a liquid propellant 145, a quantity of a monopropellant mixture 147, a gas propellant 151, or a hybrid propellant 149. The actuator component 14 is embodied as a pneumatic device and is open cycle. Advantages of the embodiments of the invention over conventional rammer systems are the reduced weight, reduced cost, and overall simplicity in design afforded by the embodiments of the invention.
Again, artillery with auxiliary power such as the South African G-5 may be used to power the rammers. The former Soviet 2A36 and 2A65 towed artillery pieces use a rammer. The rammer and breech of the 2A36 are operated from a hydraulic reservoir charged by recoil, but until the first shot, the rammer for the 2A36 is initially manually operated. The rammer for the 2A65 uses a spring assisted mechanism. As mentioned, these types of towed artillery pieces are extremely heavy, and may not be suitable for air transport. With regard to the reduced weight afforded by the embodiments of the invention, the actuator component 14 and pressure accumulator 19 are lighter in weight than an auxiliary power unit (APU), a hydraulic pump, and an accumulator as used in conventional ramming systems such as the man-powered South African G-5, or a hydropneumatic accumulator found in the conventional former Soviet 2A36 system, or the spring-assisted components of the conventional former Soviet 2A65 system.
Moreover, the consumable propellants 141, 145, 147, 149, 151 are also lightweight, and the nontoxic monopropellant mixture 147 exhausts steam and oxygen from the decomposition of hydrogen peroxide or gases from liquid artillery propellants, which then may be vented at low pressure. According to the embodiments of the invention, regeneration saves consumables propellants, and using a gas generator on each loading saves weight mounted on the gun at the expense of consumables propellants.
The embodiments of the invention provide a rammer system 1 that is sufficiently lightweight to be dismountable and transported separately from other artillery pieces to save weight when sling loading, if necessary. Because there are no hydraulic reservoirs or motors on the rammer system 1, the rammer system 1 could slip over studs on the carriage of the gun, perhaps engaging the recoiling mass by a pad, could be removable, and could be lifted by as few as two crewmen.
Other advantages afforded by the embodiments of the invention are increased speed, reduced fatigue, reduced heat stress when wearing chemical protective gear, especially overgarments, reduced personnel requirements, and increased safety. With regard to speed, the projectile or propellant charge 34 may be placed on the loading tray 36 and immediately rammed. The process and time for fitting a ram staff on the item to be rammed, getting the crew ready, and ramming, are reduced to the setting of a control.
With regard to reduced fatigue, a 155 mm projectile M107 High Explosive weighs approximately 95 pounds. Ramming a 95 pound projectile up an 85 degree slope (maximum elevation) hard enough to seat the projectile in the rifling requires significant effort. The propellant (powder) charge is of comparable weight. The OF-29 unitary HE projectile for the 2A36 152 mm towed artillery piece is 101 lbs (46 kg). The charge is 76.6 lbs (34.8 kg). For those armies with heavier pieces of artillery the corresponding weights are greater. Thus, because there is already much physical exertion required to ram a projectile, the reduced weight provided by the embodiments of the invention allows for a reduction of the fatigue of crewmen.
With regard to reduced heat stress in chemical protective gear. Present western chemical protective gear is based on a layered ensemble of treated cloth and a charcoal impregnated intermediate layer. These layers reduce the effectiveness of perspiration in cooling the body. In a desert climate the effect of heat is worse. Adding heavy exertion makes the heat load difficult to cope with. Eastern designed chemical protective equipment is based on an impermeable rubber suit that completely blocks ventilation. Reduction of muscular activity to a minimum is highly desirable in both cases. As such, the reduced weight provided by the embodiments of the invention allows for this reduction of muscular activity.
With regard to reduced personnel requirements, the reduced weight provided by the embodiments of the invention allows for fewer number of crewmen required to handle the ramming of a projectile compared to conventional systems. With regard to increased safety, the various embodiments of the invention allow for increased safety of the ramming of the projectile or propellant charge. Moreover, reduction in the number of personnel required to handle the ramming as well as some of the other advantages described above further increases the overall safety provided by the embodiments of the invention.
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments of the invention can be practiced with modification within the spirit and scope of the appended claims.
