US2485601A - Multiple cartridge launcher - Google Patents

Description

Get. 25, 1949. g, K N 2,485,601

MULTIPLE CARTRIDGE LAUNCHER Fild Sept. 26, l947 4 Sheets-Sheet 2 E1 E11" ETLBE N; Hickman Oct. 25, 1949. c. N. HICKMAN uunwrrnn CARTRIDGE LAUNCHER Filed Sept. 26, 1947 4 Sheets-Sheet 3 E131" ET'ICE N-Hickman 1%. M wkawflb Oct, 25, 1949. c. N. HICKMAN MULTIPLE summer: LAUNCHER 4 Sheets-Sheet 4 Filed Sept. 26, 1947 sum EH E Q V n lll EIETETIEE N Hi|:] man Slim Patented Oct. 25 1949 UNITED STATES PATENT OFFICE resented by the Executive. Secretary of the ffice of Scientific Research, and. Development Applicationls eptember 26,1947, Serial N o. '17 6,391

3 Claims. (Cl. 244-453) (Granted. under. the act of March- 3, 1883, as

amended. April 30, 1928; 370 0.: G. 757) The invention described herein may bemanufactured and used by the Government for gov ernmental purposeswithout the payment of any royalty thereon.

This invention relates to a launching device for rocket projectiles, and in particular for winged rockets of the type having a wing loading too great for self-launching due to the inability to obtain, by jet propulsion alone, a speed greater than its stalling speed. In such a case external power must be lent for the take off..

Such devices, broadly, have been known and used, and in particular, rockets have been powered for take on by the use of concentrated hydrogen peroxide in the catapult.

The present invention is concerned; with, a method and means for catapulting' missiles wherein a conventional propellant, such as smokeless powder, is employed, and the necessary energy is supplied stepwise as the missile proceeds along the launcher, the release of energy being occasioned by the missile itself in. passage.

It is, therefore, an object of' the invention to provide a launching device wherein propulsive energy is supplied in increments, further objects being to provide novel means for communicating propulsive energy in a launching tube to-an external projectile, utilizing available energy to the maximum degree and with optimumacceleration performance of the projectile.

To these and other ends, reference, is had to the accompanying specification and claims, and. to the drawings, in which:

Fig. 1 is a side view of a launcher with rocket in place,

Fig. 2 is a top plan view of Fig. 1 without the rocket,

Fig. 3 is a section taken on the line 3-3 of Fig. 2,

Fig. 4 is a section taken on the. line. 4-4 of Fig. 3,

Fig. 5 is a section taken on the, line, 55 of Fig. .3,

Fig. 6 is a section taken on the line. 6-6 of Fig. 3,

Fig. '7 is a side view in partial axial section of an electrically actuated cartridge and holder,,

Fig. 8 is a section taken on the line 8-8 of Fig. '7,

Fig. 9 is a side view in partial axial section of a percussion cartridge. and holder,

Fig. 10 is a longitudinal section of alauncher withmodified sealing means,

Fig. 11 isa partial. end view-of Fig. 10, and

} pipe.

2 Fig. l2'is a-sectiorr taken onthe linel2 l2' of-Fig; 10.

The launcher shown comprises a mairr sup porting member I- held on standards? of" varying height to afiord an angle of attack (or ele vation) for the missile to be'launched; andhaving cross webs 3. A series of ribs 4 atop the member I support a' launching deck 5-andalso serve to" hold and strengthen against bursting the pressure-' tube 6.

Thedeck and tubehave'alig-ned slots Tand 8 throughout their length for communication from the missile, such as 9 tothe interior of thetube. A piston. III is slidably-fitted in-the tube 6; and

has-a bore M (Fig. 3) receiving a pipe H the purpose of which is. to sealthe slot 8against escapeof gases inthe region behind the-moving pistom. The pipe is-1preliminarily held near the slot 8.by means such as a wire loop l3 andcross member ltwhichmerely rests on' the tube 6-(see Fig. 6.)

The piston Ii) carriesahook l5;which.passes= up.through. slots 822.111.7111]. position toengage. a portion of the missilasuchaseye lug [6, to;

impart: motion. to the: missile. The bore Id of the. pistonis shown slanted to provide spacezon, the; front. side of. the piston for; the hook; A: sled is provided for. the missile.

Therear end of the; tube 6. is sea1ed,,asby a. plug. ll, shownthreaded. therein, and an.adjust-.- ment member is provided. to .vary the initialmosietionof the piston. This member may: comprise a rod l8 threaded through.

It, will. now be apparentthatupon develop:-

3 ment. of. pressure behind the piston,v the. latter; willprogress along the tube, carrying, the missile:

with it. Duringthis, movement the tubeisswept: of hangers l3, and the sealing, pipe. 12 is. laid; up against the. slot 8 whereit is retainedby the pressure in the tube until the pistonhasbeem ejected, after which it falls to the bottom of. the

tube. The pipe may be restrung for reuse.

In Fig. 10 is shown a modification wherein a; sealing ribbon I2 is employed in place of the In this case the ribbon isattachedas at l9 at the breech of the tube. It is maintained near theslot 8' by an articulated member ill attached. to the piston of. a. pneumaticzjacls 24 which servestotake upundue slack. in. the ribs ban. The operation issimilar to. the otherde.--

scribed modification except that in.lieu.of.sweep.-- ing outhangers, the piston merely breaks; the; connection. of the tape at and rotates the member 20.

55, Withthelengthof tube. employed feet iny a given case) and relatively small bore, ballistic theory as expressed by the equations of motion, state, energy and burning for explosive charges cannot provide for the propulsion of a considerable mass by a single charge. The propelling effort is therefore accomplished by a series of charges spaced along the tube and initiated only after passage of the projectile. For the first of these an electrically fired cartridge has been found to be satisfactory but, for all subsequent charges, percussion firing has been found to be of best advantage.

The electric cartridge is shown in Fig. 8. The

container 22 is screw threaded into an adapter 23 which fits in the tube 6. It is closed by a cap 24 to which is attached a plastic toroidal-shaped member 25 containing an igniting composition 26 with embedded filament 27. Also in the cap is a plug contact 28 and insulator 29. The contact leads tothe filament and through ground to a source of E. M. F. The cap 24 also bears wormhead 'wires 30 which carry tubular sticks of propellant 3| as in rocket chambers. A metal plate 32 with an opening 33 acts as a partial confinement to insure good ignition of the powder charge. A cover plate 34 to keep out moisture and dust normally seals the opening 33 but is rupturable by the propellant. The percussion cartridge in Fig. 9 has an outer case 35 and an inner case 35', the latter being roughly similar to the electric cartridge, but having a conventional primer tube 36 with percussion igniter 37 carried in a head 38 which also carries trap wires and propellant. A plate 39 fixed in the forward end has numerous large through openings 40 normally covered by a thin magnesium plate 4| held temporarily in place as by a friction fit, for which purpose it may conveniently have a flange 42. The whole inner case is slidable in the outer case against the bias of a spring 43 contained in a well 44 in the head 45 of the outer case which also carries a fixed firin pin 46 threaded through the head for adjustability and having a locking nut 41.

The percussion cartridge is operated by gas pressure in the main tube 6. As the piston passes the inner end of a cartridge case, the propellent gas pressure operates on the thin plate 41 which is backed up by the plate 39. With obturation at this end, the entire inner case is urged toward the head 45 of the outer case and the igniter 31 is brought into firing engagement with the point of pin 46. The propellent blast which follows blows the thin plate 4| into the main tube 6 and the propellent gas pressure is superimposed on the pressure already existing in the tube. Thus the timing is automatically controlled by the spacing of the cartridges along the tube.

In one successful embodiment a total projectile load of 5400 lbs. was accelerated to a speed of 240 miles per hour with a maximum acceleration of about 17 g in a distance of 160 feet, the maximum tube pressure being 850 to 900 p. s. 1. Total ejection time was about 0.85 second.

The ballistic conditions in a launcher as described herein are radically different from those obtaining in ordinary guns where a high velocity is attained in a very short time interval. Ordinary theory is not applicable in the launcher for two main reasons: (1) The rate of burning is not proportional to the pressures of less than 1000 p. s. i. as they are at pressures of 30,000 p. s. i. or above found in guns, and (2) in the launcher, powder surfaces are introduced at specific time intervals. In addition, heat losses are considerably greater in the launcher.

In the solution of the problem by entirely unconventional methods, a main objective was to obtain as nearly, as possible, a constant pressure in the launcher, and I have found that in order to accomplish this the powder burning surface must increase linearly with time. To this end I have found that a single-perforated grain such as employed in rockets and which has an almost constant burning surface had a favorable bearing on the result. Cartridges having such grains are introduced at various times so that the total burning surface, although not increasing exactly linearly with the time, il creases stepwise in such a 'way as'to approximate a linear rate. Such increments may be distributed in large number with small charge and narrow spacing or with larger charge and wider spacing. It was found that six charges were suflicient, for the foot tube employed, to give a. reasonably uniform pressure.

The charges may be introduced throughout the total time in which case much of the later charges will be unconsumed, and result in after-burning, chufiing, flash and smoke. For this reason it is preferable to introduce charges for only part of the time even though this results in the pressure falling off toward the end of piston travel. I have found that an adequate situation exists when charges are introduced for only about one-half the total time, using a web of powder that is completely consumed in one-half the total time.

I have further found that the weight of charges should be equal, except the first, which should have half the weight of the others, and that the charges should be spaced at intervals which in each case correspond to the total burning of the previous charge, and I have further found that the piston should have an initial position leaving a clear space of about one foot in the rear of the tube.

The employment of a rocket-type charge in the launcher is not obvious, and it was a matter of discovery that elicited the fact that the powder was erratic and subject to cracking and general breakup when not trapped, and it was further found that faster ignition in the later rounds occurred with percussion firing as compared with electrical firing.

Having now described my invention, what I desire to claim as new and secure by Letters Paten 1s:

1. A launcher for missiles comprising a ramp, there being a longitudinal slot in said ramp, a barrel member under said ramp and having a slot aligned with the slot in the ramp, sealing means for the slot in the barrel member, temporary suspension means for the sealing means, a piston in said bore surrounding said sealing means and urging the same into sealing engagement with the barrel slot, and means on the piston passing through both said slots for engagement with a missile on said ramp.

2. A percussion firing cartridge comprising an outer casing having an open end, an inner casing slidable in said outer casing and carrying a propellant charge, complementary ignition means on the respective casings constructed and arranged for actuation on relative sliding of said casings, a spring member biasing said casings to safe relation, valve means carried by said inner casing adjacent said open end and arranged to permit gas discharge from said inner casing through said open end but effecting piston action of said inner casing in response to fluid pressure incident through said open end into said outer casing, said valve means comprising an end plate having an orifice and a cover plate releasably held externally of said end plate and covering saidorifice.

3. In a launcher for a missile, a flat elongated deck, a barrel, means uniting and supporting "said barrel and deck in closely-spaced parallel relation, there being a first longitudinal slot insaid barrel and a second slot in said deck adjacent and parallel with said first slot, said slots'extending throughout the length of said decl; and barrel, respectively, a piston slidably fitting said barrel, means connected with said piston and extending through said slots for connectionfwith a missile slidable on and along said deck, sealing means mounted within said barrel adjacent its slot for movement into sealing relation therewith, there being a connection between said piston and sealing means operable to move said sealing means into sealing position in response to passage of said piston therealong, a plurality of longitudinally spaced cartridge casings spaced along said barrel and communicating therewith, each casing adapted to contain an explosive charge, and

5 means responsive to the passage of said piston adjacent each said casing to fire the same.

CLARENCE N. HICKNLAN.

REFERENCES CITED 10 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1 200,740 Lyman Feb. 26,1878 2,200,427 Merz May 14, 1940 2,360,217 Francis Oct. 10, 1944 FOREIGN PATENTS 20 Number Country Date 478,427 Great Britain Jan. 18, 1938

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