US1413534A - Recuperator system for cannon - Google Patents

Description

B. B. HOLMES. I RECUPERATOB SYSTEM FOR CANNON- APPLICATION FILED JUNE 1, 1919.

1,413,534, Patented Apr. 18, 1922.

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B. B. HOLMES.

RECUPERATOB SYSTEM FOR CANNON- v APPLICATION FILED JUNE 7, I9I9- 7 1,41 3,534. at nted pr- 18, 1922.

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THE UNITED STATES ARMY.

REC'UPERATOR SYSTEIVL FOR CANNON.

1919. Serial No. 302,418.

(FILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L, 625.)

To all whom it may concern:

Be it known that I, Bnnoronn B. HOLMES, or, Coast Artillery, United States Army, a citizen of the United States, stationed at Washington, District of Columbia, have invented an Improvement in Recuperator Systems for Cannon, of'which the following is a specification.

The invention described herein may be used by the Government, or any of its officers or employees in prosecution of work for the Government, or by any other person in the United States, without payment to me of any royalty thereon, in accordance with the act of March. 3, 1883.

This invention relates to improvements in a recuperator system for cannon and relates particularly to a single hydrdpneumatic mechanical system which serves both as a brake to check the momentum of the gun in recoil and as a means to place the gun back into battery in counter-recoil.

In present mechanism of this character, there are provided a recoil cylinder adapted to contain oiland a recuperator cylinder adapted to contain oil on one side of a piston therein and air or a gas 'on the other side thereof. The oil portions of each of these cylinders are connected by a port whereby pressure exerted upon the oil in the recoil b'ake cylinder, upon recoil of the gun, is transmitted to the oil in the recuperator cylinder which pressure acting upon its side of the piston therein forces the same along the cylinder and compresses the air on the other side thereof, the said air thereby acting as a cushion in the said recoil movement and serving in its reactionv against the piston to restore the gun to battery. The port connecting the two cylinders is 'usually'provided with a valve for controlling the flow of oil during recoil of the gun, This construction entails an enormous amount of work and expense in its manufacture since the air-oil recuperator cylinder mustbe machined and polished to the finest degree to fit its piston very accurately and the piston must be polished in a like manner and specially built-up to withstand the exceedingly high pressures involved. The construction is also objectionable in this, that the piston can not be made tight enoughto entirely prevent leakage and thereby a mixture of oil and air and a decrease of the air pressure.

It may be further stated that the oil-air pistonused in the present type of recuperator must be made to; fit its cylinder so tightly that an enormous frictional resistance to its lineal movement is developed, a pressure of several tons usually bein required to move the same. The present inventron entirely overcomes this objection.

It 1s an object of the present invention to provide a mechanism wherein the above enumerated objections, and other minor obectlons not enumerated, are entirely eliminated. To this end the construction of the present invention is very easy and cheap to manufacture, particularly in this, that a 7 separate. collapsible air container or bellows is provided to be placed within the recuperator cyhnder, such container being of simple yet of very substantial character and cheap to manufacture. This construction entirely eliminates the piston heretofore used and the air cylinder heretofore entailing such heavy expense in manufacture need now only be rough machined to provide a housing for the air bellows. This bellows is of sheet metal entirely closed in such manner that leakage of any air is impossible and the frictional resistance therein is negligible since the bellows is entirely flexible and has a smooth sliding fit within its cylinder.

While I have shown the invention as par ticularly adapted for use in the recoil mechanism of a gun, yet it is obvious that the construction herein defined may be adapted to a variety of uses and therefore I desire it understood that the invention is not limited to the particular art or combination Fig. 3 is a cross section taken on linemounted, the cradle being provided with guides 4: to receive the gun and the guides 5 to receive the complemental guides 6 on the recoil mechanism 3. The breech lug 7 of the gun is secured to the recoil mechanism" The recoil meche at 8 in the usual manner. anism consists broadly of the oil brake cylinder 9 and two air recuperator cylinders 10 with their operating parts. While two recuperator cylinders are herein shown and described it should beclearly understood that the invention contemplates either a single cylinder or a plurality of cylinders. V

Referring more specifically to the recoil mechanism, 11 indicates the oil brake. piston provided with a piston rod '12secured to the cradle cap 13 by nut 14, the said rod passing through a gland 15 screwed into the end of cylinder 9. 'By this construction the piston 11 is held stationary with the cradle. Port 16 opening into the front end of cylinder 9 and extending as at 17 and opening into the rear end or one recuperator cylinder at 18, provides an oil communication therebetween. Adjacent to port 18, the two recuperator cylinders are connected by a port A separate collapsible air container or bellows 20 is mounted in each recuperator cylinder 10. This bellows, except for the ends thereof, is of one-piece continuous resilient sheet metal normally extended as shown in F 2. The inner end thereof is closed by a separate piece forming a piston 21. The outer end closure is in the form of a screw plug .22. The plugs 22 are each formed with a vent 23 connected by a pipe 24 secured to the plugs by means of clamps 25. This connection serves to provide a balanced or equal pressure in said bellows. The desired pressure maybe maintained by forcing air into the bellows through the valve 26. The space 27 between thebellows and the inner surface of each recuperator cylinder 10 is normallvfilled with oil and such surface is longitudinally grooved at 28 to provide a passage for said oil upon the collapsing of the bellows.

As shown in Fig. 2, the inner end of the bellows extends short of the end of the cylinsection through such der thereby leaving a space 29. By this provision, the bellows is free to expand to always maintain a, balanced pressure between the oil in the cylinder and the air within the bellows. The oil being free to surround the entire exterior surface of the bellows, the pressure upon such surface is always equal to the pressure upon the inner surface thereof. Such construction prevents the bursting of the bellows. However to be doubly sure of preventing such rupture of the bellows, a safety valve 30 is provided in the end 21 thereof. As long as the pressure on either side of this valve is approximately equal, the valve provides a complete closure but should the bellows expand suiiiciently, owing to escape of oil, to allow the piston 21 to reach the end of the cylinder, the bellows would be prevented from further expansion and the pressure therein become excessive to the oil pressure in the cylinder, but before the excess pressure within the bellows could become great enough to rupture the same, the valve -.would blow out and prevent such rupture.

It is often desirable and may be necessary in some guns, as where the force of recoil is very great, to decrease the compressibility of the bellows without increasing or diminishing the length thereof or without changing the oil pressure in the recuperator cylindeiy This may be done by partly, filling the bellows with oil Or other liquid thereby using amixture of'liquid and air or gas instead of the latter alone. A liquid being less compressible thana gas, the bellows with such a mixture therein would be much more diflicult to compress.

Upon the recoil of the gun a vacuum is necessarily formed behind the piston 11. a port 33 having a plug with a small hole 34 therein is provided at this end of the oil cylinder to let a small quantity of air into such vacuum chamber. This portion of air serves to cushion the gun upon the final movement of its return to battery.

The port 17, providing communication between the oil cylinder 9 and recuperator cylinders 10, has a controlling valve 35 and a check valve 36 therein. Both these valves operate automatically upon recoil of the gun. The valve 35 is normally open (when the gun is in battery) as shown in Fig.5. This valve is operated by means of an arm 37 thereon riding within thegroove of an elongaged plate 38 secured to the cradle. This plate, as shown in Fig. 7, extends angularly to the cradle and upon rearward movement of the recoil mechanism the arm 37 is gradually moved to the right (Fig, 4) thereby closing the valve 35. The valve is normally open when the gun is in battery and 'nearly closed at the extreme end of recoil. Bythis construction the gun is allowed to recoil quite freely upon the first shock of the explosion of the charge and such recoil is gradually checked along the entire path of recoil and finally fully checked at the end of such path. It may be stated that the angular'positio-n of plate 38 may be varied or changed if desired to change the lengthof recoil.'

The check valve 36 is normally held to its seat by means of spring 39. Upon the recoil of the gun, the oil forces the valve away from its seat against the action of the spring 39, thereby leaving free passage for the oil to the recuperator cylinders. Upon counterrecoil and as the oil starts to flow in the opposite direction, valve 36 closes and checks the flow of the oil which in such return must pass through holes to in the valve. In this manner the gun is carefully and smoothly brought back to battery.

The operation of the invention is as follows It should be clearly understood that the cradle 1 is stationary and that the entire recoil mechanism 3 recoils with the gun. The piston 11 being secured to the cradle cap 13 is also held stationary. The gun is secured to the recoil mechanism as at Sand upon recoil carries such mechanism with it in the direction of the arrow in Fig. 1. The oil cylinder 9 about rod 12, ports 16 to 19 and the recuperator cylinders 10, outside of the bellows 20, are filled with oil under a pressure equal to the air pressure within bellows 20.

Upon recoil, the oil cylinder 9 moves along piston 11 and forces oil through port 16, valves 35 and 36 (which is forced open by the oil pressure), ports 17, 18 and 19 into therecuperator cylinders 10. This oil pressure acting against pistons 21 compresses the bellows within the recuperator cylinders,

V the oil. around the bellows being allowed to pass freely along grooves 28. At the beginning of recoil, the valve 35 is wide open but as the recoil mechanism moves rearwardly the valve arm 37 riding in the groove of plate 38 thereby gradually closes the valve, the valve being nearly fully closed at the end of recoilf Upon counter-recoil, the air within the bellows 20, being compressed, tends to expand the bellows and drive the oil in the opposite direction. The check valve 36 is immediately seated by means of spring 39 and the oil pressure, the controlling valve 35 being opened as the gun moves to battery. Since the oil must pass through holes 40 in returning to the oil cylinder 9, the return of the gun to battery is gradual and smooth. The small portion of air drawn in through port 34 aids in cushioning the final movement of the gun to battery.

From the above description it is evident that the present invention is a real advance.

in the art defined and provides a mechanism wherein the objects referred to are completely secured.

Having described'my invention what I claim and desire to secure by Letters Patent, is

1. In a cushioning device of the classdescribed, a brake cylinder and brake piston therefor, a recuperator cylinder, a flexible bellows floatingly mounted in the recuperator cylinder and containing fluids, a piston head at one end of the bellows, a screw plug adapted to screw into the recuperator cylinder for closing the other end of the bellows, means to permit the flow of fluid from one side of said piston head to the other upon collapsing movement of the bellows, a passage way connecting said cylinders and a valve for gradually closing said passage during the recoil of the gun.

2. In a cushioning device of the class described, a brake cylinder and a brake piston therefor, a recuperator cylinder, a flexible bellows floatingly mounted in the recuperator cylinder and containing fluid, a piston head at one end of the bellows, a closure for the other end of the bellows adapted to secure the bellows to the recuperator cylinder, means to permit the flow of fluid from one side of said piston head to the other upon collapsing movement of the bellows, a passage way connecting said cylinders and a valve for gradually closing said passage during the recoil of the gun.

3. In a cushioning device of the class described, a brake cylinder and brake piston therefor, a recuperator cylinder, a flexible bellows floatingly mounted in the recuperator cylinder and containing a gas, a piston head at one end of the bellows, a screw plug adapted to screw into the recuperator cylinder for closin the other end of the bellows, the inner sur aces of the recuperator cylinder being grooved longitudinally to permit the flow of liquid from one side of said piston-head to the other upon collapsing movement of the bellows, a passage-way connecting said cylinders and a valve for gradually closing said passage during the recoil of the gun.

4. In a recoil mechanism, the combination of a brake cylinder and brake piston therefor, a plurality of recuperator cylinders each having a flexible bellows'therein containing a fluid adapted to be compressed, a pistonhead secured to one end of the bellows, a passage-way connecting the brake cylinder with said recuperator cylinders, a liquid contained in the brake cylinder in front of the piston for filling said brake cylinder, the passage-way and the space in the recuperator cylinders in the rear of said piston head and around the flexible sides of said bellows whereby the fluid contained within the bellows is maintained under pressure; and a safety valve secured to said piston head for permitting the escape of fluid should the pressure within the bellows exceed the pres sure on the exterior thereof.

5. In a recoil 1neehanism,xthe combination ofan oil brake a plurality of recuperate! cylinders each havinga flexible bellows containing a gas under pressure, screw-plugs for closing the forward ends of said bellows adapted to sorewinto the recuperator cylinders, ports formed through said plugs, a 10 pipe connecting said ports and a valve in said pipe whereby the gas supply of said bellows may be replenished.

BRADFORD B. HOLMES.

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