US1898772A - Rock drill - Google Patents

Description

L. W. GREVE i ROCK DRILL Feb. 21, 1933.

Filed Aug. 21, 1928 IN VEN TOR.

ATTORNEY Patented Feb. 2l, 1933 UNITED STATES COMPANY, on CLEVELAND, onto ROCK DRILL Application filed August 21, 1928. \Seria1-1\m.30lj,055.

The present invention is directed to improvements in rock drills, and has for its primary object to provide a drill constructed in such manner that the motive fluid flow- 5 ingfrom the line will be subjected to heat,

to increase the expansibility of the compressed air before it is allowed to expand.

A further object of the invention is to provide a device of this kind which will be particularly desirable at locations where air pressure is comparatively low, and will prove especially advantageous when used in connection with portable compressors of the type used for operating tools for street and road work. l

lVith these and other objects in View, as will appear as the description proceeds, the invention consists in the novel features of construction, combination of elements, and

arrangement of parts hereinafter to be fully described, and particularly pointed out in the appended claims.

In the accompanying drawing Figure l is a sectional View taken through 'the device.

Figure 2 is a sectional view o-n line 2-2 of Figure l.

Referring to the drawing, 1 designates the drill cylinder in which is movable the piston hammer 2, said cylinder and hammer being of any conventional type.

The back head 3 is formed with a relatively large air receiving chamber 4, motive fluid being led thereto throughV a port 5,

the inflow of fluid being controlled by a valve 6, operable in this instance, by a trigger 7 carried by the handle structure 8. The chamber is preferably provided with a lining 9 of suitable material having low heat conducting qualities. A lining of refractory material such as asbestos or ire brick will suflice for this purpose.

The heating unit. per se consists of a cylinder l0 formed from moisture resisting material, for example, stainless steel, as well as having great heat conductivity. Fitting snugly upon the cylinder is a sleeve 1l of suitable insulating material for example, porcelain, and in which is formed a plurality of perforations l2. This sleeve is of the LOUIS w. GREVE, or CLEVELAND, OHIO, AssrGNon 'refrain cLnvnpeNnnocizfnnirL Same lillllgtll as the Cylinder l, v.affidiZlib-,0111i i i have ytheir lower ,ends resting Lupon, the spacing lmember 13 which serves. to ,maintain the same zfirmlymin the-chamberA, ,and spaced fnoinfgthe side v-Wall'tliereof. .The outersur'- face of the SleeveiS-fgrooved, as. -atleiolt retaining the lwire 15 properly wound, V1 -he terminals 16` andy lltbereof being connected in ,the receptacle H1,8, said receptacle being of conventional form 3and is lunounted inthe/re? lcess l9fformedin the .wall of the chamber.

This receptacle :is y.retained :in ,placefbyfthe plate 20andit .will ,be obviouslthat `when la plug, connected in circuitwitha lsourcebf electrical energy isengaged in the receptacle, theswire l5 .will vaber heated. .Qbviouslvthe heat from the wire l5 will radiate through theperiforations .off-thefsleeve, thus heating thecylinder 10 in order that the motive fluid passing through the cylinder will be heated thereby increasing the potential expansive power of the motive fluid just prior to the time it enters the piston chamber to act upon the piston and thus greatly increasing the efliciency thereof.

What is claimed is l. In combination with a drill cylinder having a hammer piston reciprocatively mounted therein, a back head, a heating chamber disposed within said` back head having heat insulating walls, a heating unit disposed within said heating chamber, said unit being coextensive with said chamber and having walls parallel and spaced from said chamber walls, a spacer disposed between said back head and said drill cylinder, said spacer adapted to maintain said heating unit in position within said heating chamber with its ends in engagement with said back head and said spacer, and means for conducting motive fluid from a source of supply through said heating chamber and unit to' said drill cylinder.

2.y In combination with a drill cylinder having a hammer piston reciprocatively mounted therein, a back head, a spacer member disposed between said drill cylinder and said back head, an enlarged chamber Wit-hin said back head having a lining of heatinsulating material, a cylinder of high heat conducting material, disposed Within said chamber and in abutting relation with said spacer member and back head, a sleeve of electrical insulating material disposed about said cylinder', heating coils supported by said cylinder, and means Jfor conducting motive fluid from a source of supply through said heating chamber andA cylinder to said drill cylinder. g. E* ,Y 1o 3Q In rcombination With a drill cylinder having a hammer piston reciprocatively mounted thereinya back head, a spacer member disposed between said drill cylinder and said back head, an enlarged heating chamber within said back head having a lining of heat insulating material, a heating unit disposed Within said chamber, said heating unit being in the form of a metal cylinder having walls of relatively high heat conductivity7 ay porous electrical insulating member surrounding said metal cylinder, a resistance coil Wound onfsaid porous member; said unit being spaced from the Walls of said heating chamber and having its ends abutting said back head and said spacer' member and being held in position by saidback head and member, and means for conducting motive fluid from a source of fluid supply through said heating chamber and unit to said drill cylinder. Y In testimony whereof I affix my signature. Y

' LOUIS GREVE.

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