US314298A - Pneumatic cannon - Google Patents

Description

(No Model.)

D. M. MEFPORD. PNEUMATIC CANNON.

Patented Mar. 24, 1885.

Illfilllllllllllff N. PETERS. Plmto-Lilhographar. Washington, D.C,

provided with trunnions.

UNITED STATES PATENT OFFICE.

DAVID M. MEFFORD, OF TOLEDO, OHIO.

PNEUMATIC CANNON.

SPECIFICATION forming part of Letters Patent No. 314,298, dated March 24, 1885.

Application filed March 17, 1884. (No model.)

To aZZ whom it may concern.-

Be it known that I, DAVID M. MEEEoRD, of Toledo, in the county of Lucas and State of Ohio, have invented certain Improvements in Pneumatic Gannon, of which the following is a specification.

Pneumatic guns, in order to possess the highest degree of efficiency, are necessarily made with barrels of greatlength, commonly of forty feet or more, the barrels being of relatively small diameter and usually of thin material.

In consequence of these facts difficulty is eX- perienced in sustaining the barrels and maintaining them in a straight and true condition, and also in preventing their vibration when in use.

My invention consists in various details of construction, hereinafter described and claimed, designed to impart stiffness to the structure,and to deliver the air with maximum effect against the projectile.

Referring to the accompanying drawings, Figure 1 represents aside elevation of my improved gun, Fig. 2, a longitudinal vertical section of the same; Fig. 3, atransverse section of the same on the line 00 .r, showing in their preferred form the clamps by which the barrel and magazines are united. Fig. 4 is a cross-section on the liney y, ShOwing the clamps Figs. 5 and 6 are views illustrating the combination of the barrel with three and with four reservoir-tubes, respectively.

Referring to the drawings, A represents the barrel of the gun, which may consist under ordinary circumstances simply of a straight tube of uniform diameter.

B B represent the two reservoir or magazine tubes, which are commonly made of a cylindrical form and of a diameter considerably greater than that of the barrel.

by mechanics in similar cases.

working under high pressures the inner surfaces of the tubes may be coated with zinc, tin, or resinous or other matters adapted for the purpose. At the rear end the barrel is connected with the two magazines by means of a breech-section, O, which may be given any external form or configuration desired, which is provided in the forward side with openings to receive the ends of the barrel and magazines, as shown.

The connection between the parts may be effected in any of the various modes practiced It is preferred, however, to thread the barrel and'magazines externally and screw them firmly into corresponding openings in the breech-piece, as shown. It is to be noted that the breechpiece is made of large size in relation to the other parts, and adapted to retain a large quantity of air directly in rear of the barrel, which has its bore continued through the breech end directly into the breech-section, as shown. This construction is advantageousin that it permit-s a large volume of air to pass directly into the barrel without changing its direction or course of movement, whereby the pressure is rendered more fully available against the projectile during the exceedingly short time which is required for the delivery of the projectilefrom the muzzle.

In practice it is found that the time required for the expulsion of the projectile is so brief that if the air is compelled to change its the present invention having no special refer- 9 once thereto. In advance of this valve the barrel is provided with a movable breech-section or breech -block, I, arranged to swing upon trnnnions, or otherwise movable in such manner that it may be opened laterally, so asto expose its ends and admit of the projectile I placed on a narrower carriage, and to be operated with greater convenience, and also in that being introduced.

In order that the magazines may properly stiffen and strengthen the barrel, and also prevent or counteract its strong tendency to vibrate, I connect the magazines and barrel firmly to each other at various points in their length by means of clamps K. The magazines being of tubular form possess great stiffness or rigidity in proportion to their weight, and being of considerable diameter they serve through the clamps to impart great stiffness to the barrel. Inasmuch as the magazines are ordinarily shorter than the barrel, and inasmuch as bodies of different lengths vibrate under ordinary circumstances in different times, it follows that the tendency of the barrel to vibrate will be counteracted by the vibrations which may occur on the part of the magazines.

The clamps K, which may be variously constructed, are preferably composed each of two castings, (1, adapted to span the magazines and the intermediate barrel, and especially on their inner surfaces to conform closely thereto, and the two parts thus applied will be united by means of bolts 1) or other fastening devices, by which they may be drawn tightly into position upon the intermediate parts. The clamp at the inner or middle portion of the gun, or at the center of weight, may be cast with trunnions c thereon, to give support to the gun and admit of its being mounted in a carriage of ordinary construction.

When the gun is to be worked at very high pressure, or when for special reasons a very large quantity of air is to be accumulated, I propose to employ three magazines grouped about the barrel, as represented in Fig. 3, or four arranged in the positions represented in Fig. 4.

I am aware that two short reservoir-tubes have been arranged at the sides of a gun-ban rel, and connected there with the two extremities; and this arrangement I do not claim, in asmuch as the union of the parts at their eX- tremities only was not designed to and will not in practice prevent that tremulous motion or vibration which is established by the handling and firing of the gun when made of the great lengths which recent experiments have demonstrated to be necessary.

It is manifest that when the barrel and magazine are connected at two points only they are perfectly free to vibrate independently, whereas the use of three or more connections renders the independent vibration impossible. The vibration of the three members in unison, particularly when the parts are of difierent lengths, and therefore adapted to vibrate in different times, is practically impossible.

The arrangement of the magazines above and below the barrel, instead of at its sides, is highly advantageous in that it reduces the width of the gun, and permits the same to be it permits the employment of the breechblock opening in a lateral direction, which is in practice desirable on account of the convenience of access thereto. It is further advantageous in that the resistance of the upper magazine to tensile strain, and the resistance of the lower magazine to longitudinal compression, are rendered available to assist in supporting the barrel, which would not be the case were the magazines arranged at the sides of the barrel.

Having thus described my invention, what I claim is 1. In a pneumatic gun, a barrel having its bore continued directly through the rear end, two magazines located on opposite sides of the barrel, and a breech-section connecting the rear ends of the two reservoirs with the .open breech of the barrel.

2. In combination with the airreservoirs and the intermediate gun-barrel, the metallic clamp connecting both reservoirs with the barrel, and provided with trunnions or bearings.

3. In a pneumatic gun, a plurality of parallel elongated reservoirs, in combination with an intermediate barrel, a valve through which the barrel communicates with the reservoirs, and a movable breech-block in advance of the valve, to permit the introduction of the projectile.

- 4. In a pneumatic gun, a reservoir to hold compressed air or gas, a barrel fixed in rela tion thereto, a valve for opening and closing communication between the barrel and reservoir, and a breech block or section opening laterally from the barrel in advance of the valve, to permit the insertion of the projectile.

5. In combination with the parallel reservoir, tubes B, and the intermediate barrel, A, the clamps K, each composed of two parts united by bolts, as described and shown.

'6. In combination with the breech section or reservoir, the two cylindrical reservoirs, and the intermediate barrel, all screwed thereto, the bore of the barrel being continued through its rear end and opening directly into the interior of the breeclrsection, as shown.

7. In a pneumatic gun, a barrel having its bore continued through the breech end, iir

combination with an airretaining chamber of relatively great diameter arranged directly in rear of the barrel, and a plurality of reservoir-chambers connected at their rear ends to the air-retaining chamber, and extended thence forward along the sides of the barrel, substantially as and for the purpose described.

DAVID M. MEFFORD.

Witnesses:

J OHN T. ARMS, WM. H. SHIPLEY.

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