US41662A

US41662A - Improvement in ordnance

Info

Publication number: US41662A
Authority: US
Publication date: 1864-02-16
Anticipated expiration: 1881-02-16

Description

T. A. BLA KELY.

Ordnance.

Patented Feb. 16, 1864 Witnzsses.

N.PETERS. PHOTO-LrmnGRAPNER. vnsmNGToN, o CA UNITED STATES PATENT OEEICE.N

THEOPHILUS A. BLAKELY, OE LONDON, ENGLAND.

IMPROVEMENT IN ORDNANCE.

Specification forming part of Letters Patent No. 4 1,662, dated February IG, 1864` To all whom t may concern:

Be it known that I, THEorHrLUs ALEXAN- DE a BLAKELY, of Montpelier Square London, England, late captain Royal Artillery, have invented Improvements in Ordnance; and I do hereby declare that the following is a full and exact description thereof'. f

The inside ot' a tube being more stretched by pressure from within than the. middle and outside, in about the ratio of the squares ofthe diameters ot1 the layers, I patented in Great Britain, in February, 1855, a method of obtaining increased strength in ordnance by build ing cannon ot' two or more concentric tubes, of which the outer compress theinner to a definite degree, so that on the gun being tired all the concentric tubes act together in resisting the strain. This method has been much used, particularly in America, by Mr. Parrott. Another method ot increasing the strength of cannon has been used by the Dutch, and proposed in England by Captain Palliser. It consists in placing a very yielding materialsuch as bronze or wroughtiron-inside of cast-iron, Without any compression of the iuner tubes or extension of the outer. Ihis latV ter plan is not applicable for large ordnance of great power, because metals cannot be found possessing both suiiicient difference ot extensibility and at the same time the other qualities required for ordnance. I therefore make cannon in the following manner: .l build the gun of concentric tubes, the inner tube being of a material that is most extensible within the elastic limit, the next tube less extensible within the elasticlimit, and so on, decreasing in extensibility within the elastic limit to the outside. I do not, however, merely tit the tubes'together, but I but on each successive layer with so much initial tension that the whole 'shall be worked by pressure from Within to, about the same degree-that is to say, the initial tension ofthe successive tubes shall compensate for an y deciency in the extensibility ofthe tubes within them, so that all the tubes shall contribute' equally of their strengtho resist pressure from within. I prefer that no partshall be stretched more ythan two-fifths as much as would canse permanent sensible enlargement. Hard steel is a suitable material for the outer parts and mild steel for the inner. However, I tind it convenient sometimes to use wroughtiron, bronze, or soft steel or steel hardened in oil t'or the inside, and various qualities of cast iron for the center and outside parts; or sometimes I use cast-iron for the center part orl cesses of hardening and annealing, &c. The

strengthening is 'not necessar t the whole length of the gun.

The accompanying drawing is a section ot' a four and three fourths inch gun [have made. A is a tube of mild steel, surrounded by B, a tube ot' harder steel, over so much of its length as is necessary to resist the pressure of the gas of the gunpowder where great. Before being put on, the inner diameter ot' B was about one two hundredths part ot' an inch less than the outer diameter of A, because the inside of B could stretch without risk ci' injury so much more than the outside of A would be. stretched when the inside of A was extended so far as consistent with pert'eet safety.

I claim- The manufacture of cannon composed ot' two or more tubes having successively-decreasing amounts ot' extensibility within the extensible limit, (the inner tube having the greatest amount,) when these tubes are put together with initial tension, substantially in the manner and for the purpose described.

T. A. BLAKELY.

Witnesses It. A. BROOMAN, I. C. MEWBURN,

Both of 166 Fleet Street, London.