US2126792A - Cooling apparatus - Google Patents

Description

Aug. `163, 1938. s. H. MacGRl-:GOR

COOLING APPARATUS vFiled March 2, 1938 Inventur- 5tEp hE1LH-MacBrE nr' Attnrma "mwuvu uw A W, A w Q mm .v m E, 4 .///dhhrmmhhhnnswWn-..EHQUE r :LI l* Y m b W/:WMNMMSMQM I.,I. r m `N QN mm w N. m .n Q ""nmmh Y h NN Q N [Y m YN l .H I mlm mw 'Patented Aug. 16, 193s UNITED STATES PATENT OFFICE 3 Claims.

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) 'I'he invention described herein may be manufactured and used by or for the Goverment for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a cooling apparatus.

'I'he general purpose of the invention is to provide an apparatus in which cooling is accomplished by expansion of a compressed gas. More particularly the invention resides in an arrangement of cylinders disposed coneentrically about a member to be cooled and providing rstly for expansion of the gas in an outer chamber, secondly for heating and recompression of the gas in an inner chamber where the gas is in contact with the member to be cooled, and thirdly for expansion of the gas into an intermediate chamber.

A further object of the invention is Vto provide a speciic arrangement for a gun barrel in which the cooling inuence is extended to the ends of the barrel. l

To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claims forming a part of this specication.

A preferred embodiment of the invention illustratedin connection with a gun barrel, is shown in the accompanying drawing, in which,

Fig. 1 is a longitudinal sectional view of the improved cooling apparatus applied to a gun barrel.

Figs. 2 and 3 `are sectional views on the corresponding lines of Fig. 1.

reference there is shown a support 5 which is -a part of the receiver of a machine gun of the Browning type and which slidably mounts the rear end of a gun barrel 6. 'I'he support 5 carries a jacket comprising a rear end plate 1 threaded on the support 5, a front end plate 8 having a bearing 9 for receiving the muzzle end of the barrel, and an outer cylinder I0 associated with the front and rearplates. 'I'he bearing 9 pref- 4,5 erably carries anti-friction contact elements, specically balls Il, for engaging the gun barrel in rear of its muzzle.

Within the jacket and associated therewith are a rear header plate I2 and a front header plate I3 spaced respectively from the rear end plate 1 and front end plate 8 and establishing a rear chamber I4 and a front chamber I5. For convenience in assembling the rear header plate I2 has a iiange I6 threaded to both the rear end plate 1 and the cylinder I0 while the front header Referring to the drawing by characters of plate -I3 has a flange I'I threaded to the cylinder I0. The header plates carries a pair of concentric cylinders, the inner cylinder I8 being spaced from the gun barrel to provide an annular chamber I9 and the intermediate cylinder 20 being preferably disposed closer to the outer cylinder I9 and cooperating with the inner and outer cylinders to respectively provide an annular inner expansion chamber 2| and an annular outer expansion chamber 22.

A supply line ,23 including a cut-oli valve 24 is provided for admitting a gas, such as carbon dioxide, into the outer expansion chamber 22. Ports 25 in the rear header plate I2 enable the gas to flow into the rear chamber I4 which has communication withthe chamber I9 by means of a restricted passage 26 which is convenientlyv provided by spacing the header plate from the front face of the support 5. The inner cylinder I8 is formed with small ports 2'I leading into the expansion chamber 2|. The front header plate which abuts or is secured to the bearing 9 is provided with ports 28 for conducting gas from the expansion chamber into the front chamber I5; and the front end plate has vents 29.

A tubular extension 3U is formed on the front end plate in prolongation of the bearing 9 and cooperates therewith in establishing an expansion chamber 3| for the gases of the propellent charge which issue from the muzzle of the barrel. This chamber contains a liner 32 within which a ring 33 on the muzzle of the gun barrel is slidably received. When the gun barrel is in its normal in battery position its iront end is approximately in line with the front end plate 8.

A plug 34 on the outer end of the liner and provided with a bullet opening 35 serves to baille a portion of the escaping gases of discharge and to build up -pressure in thei expansion chamber 3| which acts on the front -face of the barrel and Von the ring 33, and supplements the force of recoil in moving the barrel rearwardly and insuring proper functioning of the various parts of the machine gun.

WhenV the gun is being fired the barrel rapidly attains a temperature which is greater than desired and whichinterferes with successful operation. In order to cool the ban'el, gas under pressure is admitted into the outer expansion chamber 22 where it expands and thus has its temperature lowered. The gas passes through the ports 25 into the rear chamber I4 and then through the restricted passage 26 to the annular chamber I9.

and into contact with the hot gun barrel. While in the chamber I9 the temperature of the gas is raised and its pressure consequently increased.

As the gas expands it passes through the small.

ports 2 into the cylinder I8 and enters the chamber 2l where its expansion results in a reduction of temperature. The gas in flowing towards the ports 28 to bc relieved through the vents 29 tends to cool the inner cylinder I8 and the intermediate cylinder 20 and the gas contained in the chambers I9, 2|, 22. The gas in the front chamber I5 extends its cooling influence to the bearing 9, to the muzzle of the barrel and to the liner 32 of the expansion chamber 3|. A portion of the gas flows past the balls Il and directly contacts the muzzle oi` the barrel.

I claim:

1. In a gun, a support, a barrel mounted in the support and projecting therefrom, a cooling apparatus for the barrel including an outer cyl;Y inder having a rear ond plate mounted on the support and a front end plate with a bearing for receiving the muzzle oi the barrel, rear and fronte header plates within thc outer cylinder and spaced from the rear and iront end plates to establish a rear and a front chamber, an inner cylinder xed to the header plates and spaced from the barrel to establish an annular chamber in communication with the rear chamber, an intermediate cylinder fixed to the header plates between the inner and outer cylinders and establishing therewith an inner and an outer expansion chamber, ports in the rear header plates to establish communication between the outer expansion chamber and the rear chamber, ports in the inner cylinder, ports in the iront header plate to establish communication between the inner expansion chamber and the iront chamber, means for ventingr the front chamberto atmosphere, and means for admitting a compressed gas to the outer expansion chamber.

2. In a cooling apparatus, a member to be cooled, an outer cylinder having rear and front end plates receiving the member to be cooled. rear and front header plates within the outer cylinder and spaced from the rear and front end plates to establish a rear and a front chamber, an inner cylinder xed to the header plates and spaced from the member to be cooled to establish an annular chamber, an intermediate cylinder fixed to the header plates between the inner and outer cylinders and establishing therewith an inner and an outer expansion chamber, ports in the rear header plate to establish communication between the outer expansion chamber and the rear chamber, ports in the inner cylinder, ports in the front header plate to establish communication between the inner expansion chamber and the front chamber, means for venting the front chamber to atmosphere, and means for admitting a compressed gas to the outer expansion chamber.

3. In a cooling apparatusamember to becooled, a jacket surrounding the member to be cooled and including an inner cylinder spaced from the member to be cooled, an outer cylinder and an intermediate cylinder cooperating with the inner and outer cylinders to establish respectively an .inner and an outer expansion chamber, means for admitting a compressed gas to the outer expansion chamber, means for conducting gas from the outer expansion chamber to the space between the inner cylinder and the member to be cooled, means for conducting:- gas from said space to theiv inner expansion chamber, and means for venting the inner expansion chamber.

STEPHEN H. MACGREGOR.

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