US91864A - Improvement in ordnance - Google Patents

Description

I 8 nu 1n.. ow S t e nu h S 3 W. PALLISER.

Ordnance.

Patented June 29. 1869.

W. PAI-USER. 3 Sheets-*Sheet 24' Ordnance.

' Patented June 29. 1869.

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Patented June 29. 1869.

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atwt @time WILLIAM PALLISER, OF PALL MALL, ENGLAND.'

Letters .Patent No. 91,864, dated June 29, 1869; patented fin4 England, December 10, 1867,

IMPROVEMENT IN ORDINANCE.

The Schedule referred to in these Letters Patent and making part of the same.V

To all who-m 'itfmay concern.'

Be it known that I, WILLIAM PALLIsEn, major unattached, of the Army and Navy Club, Pall Mall, in the county of Middlesex, England, have inventedv An Improved System of Strengthening or Converting Cast-Iron Guns; and I do hereby declare that the following is a :t'ull and exact description of the said invention, reference being had to the accompanying drawings, and to the figures and letters marked thereon; that is to say- My invention relates to an improved system of strengthening or converting existing cast-iron guns by the introduction of wrought-iron or steel tubes through the muzzle thereof.

One part ot' my invention consists in forming the breech-portion of the lining or barrel with two tubes, of which the inner or A tube is comparatively thin, and is constructed either of steel, of such .1 quality as will stretch, or of coiled wrought-iron, which tube I tit into a seat formed in the outer', or B tube, which extends the entire length of the barrel, and which may also be` either of steel or-of coiled wrought-iron; or, in another arrangement, I' make the A tube of the entire length-of the barrel, and I reduce the thickness of the breech-end thereof externally, and I tit the B tube over such reduced end of the A tube.

-lIn large guns, where it is not practicable to make the muzzlefeud of the A tube of such a thickness as to be equal-iu diameter to the combined thickness of the A and B tube at the breech, I increase it up to the required size by titting upon it pipes or tubes, of

cast or wrought-iron, which, in the case of short guns or howitzers, may project, together with the inner barrel, a sudicient distance beyond the muzzle of the gun to make the converted gun of the required length.

The object of making the A tube thinv at the breechend is, that should the barrel split by the action of long-continued tiring, which `it is liable to do, such split would not extend beyond the A tube, and would in consequence, only be shallow, and thus the mechanical advantage gained by the internal pressure of the gas, by means of such shallow split, would not be suicient to burst the thick B tube supported by the cast-iron casing.

It is essential, when the barrel is composed of' two tubes throughout, as last described, that a screw-collar, screwed intothe muzzle of the gun, should secure the inner tube, as well as the outer one.

Anotherpart of my invention consists in cutting a helical channel of a quick pitch, either round the external surface of the A tube or in the internal surface of the B tube, which channel communicates with an indicator-hole that passes out through the breech-end of the gun.

The object ot tins arrangement is, that should the A tube split, the gas escaping through such split will at once dnd its way through the helical channel to the indicator-hole, and thus give warning to the detachment serving the gun.

Another part of my invention consists in' combining, with a bush extending along the entire length of Vthe vent, and held in place by a screw-thread, a platinum vlining on the inside oi' its inner, or lower end.

Another part ot' my invention has reference to the riding of such converted guns.

I cause the ride grooves to terminate at a distance from thebreech-end of ythe bore, equal to about one and a half time the length of thc cartridge containing the heaviest battering-charge of powder which thegun is intended to dre, iuorder to enable the pressure of the gases to be considerably diminished before reaching that part of the barrel which is weakened bythe ride grooves.

These grooves commence with a very slow, uniformI (t. e., unaccelerated) twist, such twist being so slow that the pressure of a single stud on the projectile in each groove will not cause any injury to the drivingedgeof the grooves.

At a certain distance, which, in most guns, will vamount to about two feet from the breech-end of the grooves, the twist becomes accelerated by preference in such a manner that ifthe bore of the gnu were laid out dat, the accelerated portionwould form an arc of' a circle, to which the uuaccelerated -portion would be a tangent.

I term this system of riding partially accelerated,7 inasmuch as it is a combination of the uniform and accelerated systems.

It is essential, where the riding is stopped short, as described, and the projectiles are provided with studs toward their front ends, that the riding should at iirst be unaccelerated, since, with heavy charges of powder and longprojectiles, as, for'iustance, double shells, the front studs would otherwise damage the riding, owing to their coming into contact, at tirst starting, with the driving-edges of the grooves ata place where the twist has already become accelerated, in which, since the motion of' translation of the projectile is at first highly accelerated, theresult would be injurious to the groove.

Ou the accompanying drawings are shown various arrangements for carrying my before-described improved system of converting cast-iron guns into effect.

Figure 1, ou Sheet I, shows a longitudinal section of a converted cast-iron gun,.0, into which, after it has been bored out to the required extent, is inserted the lining or barrel, composed of the tube A, of steel or coiled wrought-iron, extending the whole length of the bore, the breech-end of which is reduced in thickness, so as to form a comparatively thin tube at that part, as shown, land upon the exterior of which reduced part is fitted the tube B.

Figure 2, Sheet I, shows a modification of this arrangement for large guna-where the muzzle-end of the'A tube, not being made equal in thickness to the combined A and B tube at; the breech-end, the muzzle-end of the barrel is built up to the required diameter by means of one or more pipes, D I), of

, either wrought-iron 0r of cast-iron, fitted on to the exterior of the A tube, and -such cast-iron pipes or tubesmay be made to project with the A tube be.

lser-ted, it is secured in its place by means of the screwcollar E, which screws into a female screw cut in the muzzle of the cast-iron gun C, and in the arrangement at fig-1, abuts against :t shoulder, a, formed on the A tube, while in the arrangements, ligs. 2 and 3, it abnts against a shoulder, a, formed on the tube D', which, in fig. 2, holds the A tube, by abut-ting, with its inner end, against a shouldcna, formed on the latter', while, in h'g. 3, the A tubc'is held by a second screw-collar, E, screwed into C, and abutting against a shoulder, af, on the D tube.

Between the outer surface of the A tube and the inner surface of the B tube, in gs. 1 and 2, is formed the helical channel l), which is either cut in the'outcr surface of the A tube, as shown, or itmay be cut in the inner surface of the B tube.

I This channel communicates at the breech-end with the indicator-hole c, passing through the breech of the Y gun., so that it' the Atub'e should split at any point,

the escaping gas will find its way through the channel b to the indicator-hole c, and thus give warning to the men serving the gun.

' In g. 3, a short inner tube, A, or chamber-liner, being litted into the recessed rear end of A, the channel b is-cut in the outer surface of the former.'

The rear end of the A tube, figs. l and 2, and of I the tube A', fig. 3, is closed by means of a cup, F, of

steel or wrought-iron.v

The female screw of the A tube, into which the cup is screwed, is formed in relief upon the tube, for the purpose of preventing the fracture of the tube at the screw-thread by longitudinal strains.

The inner bottom surface of the cup F is dat, the sharp edges of the side being rounded oli'.

The walls ofthe cup are, by preference, cylindrical, since, if the cup were conical, with a rounded bottom, which form is commonly known as the gomercham ber, the action of the gas would quickly eat a hole' into it.

The end of the B tube hasv also a relieved female screw, into which is screwed the breech-plug G, so as to press against the end surfaces ofthe A or A tubes and cup F.

The bush forming the vent H of the gun, is screwed along its entire length, as shown, and has, at vits inner end, a tubular lining, h, of platinum, or alloy of platinum, screwed into it with a countersunk head, the inner end of the bush being also, by preference, countersunk by being riveted up in a conical seat after insertion, as shown more clearly in the enlarged section at Figure 4, Sheet II, which also more clearly shows the cup F, and the rounded form of screw-thread which I prefer to employ.

Figure 5, Sheet II, shows an arrangement in which Y the B tube is made of the entire length .of the barrel,l instead of the A tube, as in the previous arrangement.

It is recessed internally at the breech-end, and into the recessed portion is fitted the thin A tube, the bevelledv front end of which is forced against the bevelled shoulder' of the B tube, by means of the breech-plug G screwed into the latter. As the screw-thread cannot in this case be made in relief upon the B tube, a circular groove, y, is cut at the bottom of the screw-thread, in order to prevent the rupturing of the gun from longitudinal strains, which might otherwise take placev at the last thread of the screw.

' A similar groove, e, is also formed for the same purpose at the bottom of the female-screw thread cut'in the muzzle of the cast-iron gun C in all cases, into 'which the screw-collar E is screwed for securing the barrel.

H'is tbe vent, with platinum lining, It. F, the cup, closing the A tube.

In this case, the whole vent of the gun is closed byA va solid screwLplug, as shown, and the new vent H is made further forward, so `as not to pass through the cup F.

This latter is also made of considerably less' depth than in the other arrangements; and instead of being forged solid, as in the formercases, it is formed as a ring, with a central screwed plug, f, having a countersunk head.

Figure 6, Sheet II, shows the same arrangement of A and B tubes as iig. 5, in which, however, the breechend-0f the B tube does not project beyond the A tube, the'plng G being dispensed with, and the A tube and cup F brought against the end of the bore of the cast iron gun.'

In all the before-described arrangements, I prefer to introduce the vbarrel into the gun in the following manner:

I bore a cylindrical hole in the gun or casing, of a slightly larger diameter than that of the barrel, so'

A`feet, and the 'remainder I bore out cylindrically.

The barrel is then turned with a corresponding conical part at the breech-end, so as to fit the conical part y of the casing, and with a cylindrical part :it the muzzle-end rather too large for the cylindrical part of the casing, after which the cast-iron casing is heated so as to'be slightly expanded, and the barrel is then dropped :into its place.

` My improved system of riding is shown at fig. 6, and in the diagram at Figure 7. I

The ride grooves l start from a point justbeyond the termination of the A tube. They commence with a uniform twist, by preference equal to about one turn in a length of one hundred calibres, proceeding thus lto the point t, a distance of about four calibres, from .which point the twist is -accelerated in the form of an arc of a circle, fi i', Iig. 7, so as, at the muzzle of the gun, to have attained a pitch equal to one turn in forty calibres.

This is seen more clearly in tig. 7, where the lines W X Y Z represent the bore of the gun with one of the riflel grooves I developed on a plane surface.

Having thus described the nature of my invention, and in what manner the same is to be performed, I wish it to be understood that what I'claim, is v l. Constructing the barrels introduced at themuzzles of converted cast-iron guns, of two .tubes at the breech-end, of which the inner, or A tube is made comparatively thin, substantially as and for the purposes hereinbefore set forth.

2.' Combining, with the inner tube of a double-tubu- 3. Constructing the barrels of 'converted cast-iron guns with an outer, or B tube, at the breech-end of larger external diameter than the muzzle-end of the inner, or A tube, and placing upon suoli muzzle-'end o f the A tube, cylinders ol' equal diameters with the B tube, substantially as and for the purposes hereinbefore set forth with reference to figs. 2 and 3 on the accompanying drawings. y

4. Forming a helical chamber between the inner and outer tubes, at the breech-'end of the barrel of converted guns, in commluiication with an indicator' passing through the breech of the gun, substantially as and for the purposes described.

5. In combination with a bush extending along the entire length ofthe vent, and held in place by a screwthread, a ,platinum lining on the inside of its inner, or

lower end, substantially as described.

(i. The improved syst-em of riflin'g guns hereinbefore Witnesses Guias. D. ABEL, Thos. TAYLOR.

set forth, in which the groovecoinmences at a distance w. PALLlsEn.

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