US2122507A - Pneumatic tool - Google Patents

Description

E. W. BALL PNEUMATIC TOOL .I uly 5, 1,938.

Filed March l5, 1957 Patented July 5, 1938 PNEUMATIC Tool.

Eldon W. Ball, Barre, Vt., assignor to Rock of Ages Corporation, Barre, Vt., a corporation of Vermont 1 Claim.

This invention relates to pneumatic tools, such as hammers, used in facing andA carving stone and in other similar operations. When such tools are used on stone, a large amount of dust and many particles of grit are set free and must be collected and removed to avoid harm to the eyes or lungs of the operator. Satisfactory removal of this dust and grit has proved a troublesome problem.

Itis the general object of my invention to provide improved and simplified means for collecting and eifectively removing such dust and grit or other fine material, without interfering with the convenient use ofthe tool.

To the accomplishment of this object, I preferably provide a suction device which is incorporated with a pneumatic tool and which is easily shiitable therewith. In the preferred form, the suction device is mounted concentric with the tool and encloses the cutting tool.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

25 A preferred form of the invention is shown in the drawing, in which Fig. 1 is a sectional side elevation of a pneumatic tool embodying my improvements;

Figs. 2, 3, 4 and 5 are sectional plan views, taken along the lines 2 2, 3 3, 4 4 and 5 5 in Fig. 1 respectively;

Figs. 6 and 1 are partial sectional elevations, taken along the lines 6 6 and 1 1 in Fig. 3 respectively; and 35 Fig. 8 is a partial side elevation of my improved tool.

Referring to the drawing, I have shown my invention embodied in a pneumatic tool comprising a piston or hammer Ill vertically reciprocating in 40 a cylinder II which is closed at its upper end by a plug I2. The cylinder II is provided with a plurality of longitudinally extending external ribs I3 (Fig. 3) enclosed by a casing I4.

Pressure passages IE extend longitudinally in the ribs I3 and are connected by ports I1 to the cylinder Il. At their upper ends the pressure passages I6 are connected to a central pasy sage lil (Fig. 6) in the plug I2. A hose connection 2t (Fig. l) is threaded in the upper end of the plug I2 and is adapte-d to receive a hose 22 through which air under pressure is supplied from any suitable source to the passages I6 and cylinder I I.

Suction passages 25 are formed between the ribs I3, as clearly shown in Fig. 3, and these suc- Application March 15, 1931, Serial No. 130,969

(Cl. Z55-50) tion passages: connect at their upper ends with a common suction passage 21 in a hose connection 28, which connection is secured to the upper end of the casing I4 by an interposed threaded sleeve 29.

A suction hose is secured to the connection 28 as indicated in Fig. 1, said hose being preferably concentric with the pressure hose 22 and enclosing the same but being of substantially greater diameter than the hose 22. Exhaust ports 10 33 (Figs. 3 and '1) connect the cylinder I I to the suction passages 25. At their lower ends the suction passages 25 connect into an annular suction passage 35 formed in a reduced lower portion or extension 36 of the casing member I4. 15

A chisel or other tool C is loosely mounted in a downward extension 31 of the cylinder II, which extension forms the inner wall of the annular suction passage 35. A suction head 40 (Figs. l and 8) preferably of rubber, is mounted on a 20 sleeve 4I, the upper portion of which is a quarter turn elliptical t in the lower end of the annular passage 35 in the casing extension 36.

While I have sho-wn certain parts of the hammer mechanism, this mechanism in itself forms no part of my present invention and it is unnecessary to describe the same in further detail, beyond stating that the hammer operates in the usual manner to apply rapidly repeated blows to the upper end of the chisel or tool C. 30

When the hammer is thus operated, the chisel is driven repeatedly against the stone, producing a large amount of dust and grit. This loose material is immediately drawn into the suction head 40 and upward through the annular passage 35, the longitudinal passages 25 and the common upper passage 21 to the suction pipe 30, through which the dirt and grit is remove-d to a suitable point of discharge. At the same time the pipe 30 receives and discharges the exhaust air from the cylinder I I through the exhaust ports 33.

The lower end of the suction head 40 is preferably spaced above the work W sufciently to permit the operator to see the work and to manually guide the chisel in a normal manner.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claim, but what I claim is:

A portable pneumatic hammer of the type adapted for surface nishing and carving operations on blocks of stone characterized by the provision of a cylindrical body for said hammer having a plurality of spaced longitudinally extending external ribs, a casing surrounding said cylinder and held in concentric spaced relation therewith by said ribs, thereby providing a plurality of longitudinally extending segmental suction passages, direct exhaust connections within said casing from said cylinder to said suction passages, a pressure tube connected to supply air to said cylinder, a suction tube concentric with and surrounding said pressure tube and connected with said suction passages, and a suction head secured to and concentric with the lower end of said casing and surrounding the hammer adjacent the work, said suction head being in direct communication with said suction passages and being thereby rendered effective to collect and remove dust Vfrom the stone surface being finished or carved by use of said hammer.

ELDON W. BALL.

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