US1236704A - Pressure-fluid tool. - Google Patents

Description

G. H. GILMAN.

PRESSURE FLUID-TOOL.

APPLICATION FILED JAN- 4. HM].

1,2 3 6, 70 4 Patented Aug. 14, 1917.

GEORGE H. GILMAN, OF CLAREMONT, NEW HAMPSHIRE, ASSIGNOR TO SULLIVAN cnusnrrs.

1,236,704. Original application filed April 22, 1908,

' Specification of Letters Patent.

MACHINERY COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF PRESSURE-FLUID TOOL.

Patented Aug. M, rem.

Serial No.'428,618. Divided and this application filed January 4,

1917. Serial No. 10,631.

To all whom it may concern:

Be it known that I, GEORGE H. Gunman, a citizen of the United States, and a resident of Olaremont, county of Sullivan, and State tion, .like characters on the. drawings representing like parts.

My invention relates to pressure flu1d tools adapted to be operated by compressed air, or other elastic pressure fiuid,"be1ng -more particularly concerned with the provision of simplified and etlicient valve controlling means therefor. This application is a division of my prior pending application, Serial No. 428,618,1il5d April 22, 1908.

My invention will be best understood by reference to the following description, when taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings:

, Figure 1 is a longitudinal, central section, taken through a pneumatic hammer embodying one form of my invention; and

Fig. 2 is a similar sectional view taken in a plane at right angles to the plane of the section shown in Fig. 1.

Referring to the drawings, and to the embodiment of my invention illustrated therein, there is provided a cylinder 1, the rear or upper (Fig. 1) end of which has threaded engagement with a hollow casing 2, the latter having a closed end and acting as a housing for the rear end of the cylinder, and a valve block-'3. The cylinder is prevented from accidental unscrewing by a split vclamping collar 4. A portion of a handlepiece 5, or other member by which the tool is supported, is shown, but it will be understood that the particular construction of handle forms no material part of this invention, and that the same may be used with various handles or other supports wellknown in the art.

The upper or rear end of the cylinder is closed by a plate 6, betweenwhich and the casing 2 a valve block 3 is -secured. The cylinder, valve block and plate, are maintained in the alinement required for the registration of their connecting passages by means of a dowelpin 8.

The head of the casing is recessed as at 9 to provide a constant pressure supply chamber, to which, when the tool is in use, compressed air or other pressure fluid isvconstantly supplied through an air inlet 10.

The valve block is of generally cylindrical shape, and has an interiorly formed valve chamber axially alined with the cylinder. The valve 11 is provided with an enlarged head 12 and a contracted head 13, the twobeing separated by an annular groove 14: and the enlarged head being also provided with a second annular groove 15. The valve chamber has an opening 16 in its rearmost end, communicating with the pressure fluid chamber 9, so that the end of the smaller head 13 is constantly exposed to pressure fluid and forced forward, The valve is shown hollowed or cored out for the sake of lightness.

The enlarged forward end of the valve works in an intermittent pressure chamber 17 communicating with an intermittent pressure passage 18 through a grooved passage 19 formed in the upper face of the plate 6. The rear contracted end of the valve chamber is provided with two annular grooves'20 and 21, each of which is connected with the rear end of the cylinder by one or mqre longitudinal passages 22 (Fig. 2).- In the forward position of the valve (Fig. 2), the groove 20 is uncovered by the end edge of the smaller valve head, and pressure fluid is admitted directly to the longitudinal passage 22, and the rear end of the cylinder. In the rearward position of the valve (Fig. 1), the groove 21 is uncovered by the inner edge of the'smaller head 13, and placed in communication through the annular groove 14 with the upper end of the enlarged portion of the valve chamber,.which latter is in constant communication with an annular exhaust chamber 23, through one or more radial exhaust ports 24.

In the forward position of the valve (Fig. 2) J, corresponding to the forward movement of 'the piston, the forward end of the cylinder is opened to the exhaust through a return passage-25, which latter connects with a lateral pfi't26 opening into the larger end of the valve chambefirt-such a point as to be uncovered by the larger head 11 and placed in communication with the exhaust port 24. through the annular valve groove 14.

During the forward movement of the piston, the valve is held in the position shown in Fig. 2 by the pressure acting against the constant pressure area at the rear end of the valve until the piston nears the end of its stroke and the delivery of its blow upon the shank of a tool .27 the latter being held within a usual sleeve or bushing 28.

Near the close of the forward movement of the piston, the controlling valve is reversed by the admission. of pressure fluid to the forward end of the enlarged portion 17 of the valve chamber, which fluid, acting against the larger pressure area of the valve at that end, acts to reverse the valve against the constant pressure upon the smaller pressure area at the rear end of the smaller head 13.

Pressure fluid is admitted against the enlarged forward end 12 of the valve, and to the lower end of the chamber 17 through the intermittent pressure passage 18 and groove 19 hereinbefore referred to, said passage opening into the cylinder through a port 29,

and also through a second and more advanced port 30.

The intermittent passage is placed in communication with a constant pressure passage 31, which latter opens into the cylinder through a port 32, by means of the circumferential groove 33 formed in the piston.

- When the circumferential groove uncovers the ports 32 and. 29, pressure fluid is admitted to the lower end of the valve chamber to raise the valve. The constant pressure passage 31 is connected at its rear end in the valve block by a transverse groove or' passage 34, which opens communication between the pressure chamber 9 and a longistant communication with the pressure fluid supply.

The exhaust space or chamber'23 hereinbefore referred to is annular, and is interposed between the valve block and the housing or casing 2, the .latter being perforated at one or more points, such as 36 and 37, so as to permit free exhaust of pressure fluid to the atmosphere through the port or ports 24.

The piston has a reduced portion 38, having sliding fit within the, contracted walls 39 of the cylinder, the effective area against which the pressure acts in returning the piston being that provided by the shoulder formed between the contracted port-ion and the main body portion of the piston.

When the return piston movement has proceeded far enough to withdraw the reduced portion 38 from the contracted cylinder walls 39, the forward end of the cylinder is placed in communication with a tool space 40, the latter being in free communication with the atmosphere through an exhaust of the valve again. from the position shown in Fig. 1 to that shown in Fig. 2, this, in turn, admitting pressure fluid to the rear end of the cylinder through the circumferential chamber groove 20 and the passage 22, as previously described.

During the subsequent forward movement of the piston, after the reduced piston portion 38 enters the contracted cylinder walls 39, pressure fluid continues to be exhausted from the forward end of the piston prior to the reversal of the valve through the return passage 25 and port 26, which latter, on the forward movement of the valve, is uncovered by the larger valve head 12, and thereby opened to the foremost end of the valve chamber. The latter is at all times open to the exhaust through the lateral exhaust port 24 formed in the Valve block (Fig. 2), and connecting the end 17 of the valve chamber with the annular exhaust chamber 23.

While I have shown and described in detail one specific embodiment of my invention, it is to be understood that the same is not limit-ed to the details shown or the construction or relative arrangement of the parts disclosed, but that extensive modifications may be made therefrom without departing from the spirit of my invention.

Having thus described one specific embodiment of my invention, what I claim-and desire to secure by Letters Patent is 1. A pressure fluid tool having a cylinder,

a piston, an imperforate diflerential valve having two heads of different diameter and two annular grooves, a valve block provided with a valve chamber having an enlarged portion and a contracted portion in which the larger and smaller heads are respectively located; a pair of ports in the contracted portion of the valve chamber communicating each with one end of the cylinder, the

valve in one position acting to open one of said ports to the live pressure and to cover the other port, andin the other position to cover the one port and to open the other port to the exhaust by way of one valve groove,

' andza port connected with the other end-of the cylinder opening into the enlarged portion' of the valve chamber, the valve in the last mentioned position establishing com-. Imunication between the-last mentioned port and the motive fluid supply by way of the other valve groove.

1 block, a pair of ports formedin the con-v the cylinder, the rear end of the valve being 2. A pressure fluid tool having a cylinder a piston, a valve provided with two heads 0 different diameter, the larger of which is provided with an annular groove, a valve block and its valve chamber in which said valve is adapted to work, the smaller head of said valve and the contracted portion of said chamber being located in the rear of said tracted portion of the said valve chamber and connected each 'with the rear end of constantly opened to pressure fluid, an exhaust passage in constant communication with the rear end of the enlarged portion of said valve chamber, and a passage connected with. the forward end' of the cylinder, said,

valve acting in one position to connect one of said ports with the rear end of the contracted portion of .said valve chamber, and, at the same time, to connect the said passage leading to the forward end of the cylinder with the rear end of the enlarged valve chamber-portibn', and in its other position to connect the remaining port with the rear of the enlarged valve chamber-portion, and the pressure supply with the passage leading to the forward end of the cylinder by way of said annular groove in the larger head of said valve.

3. A pressure fluid tool having a cylinder, a piston, a differential valve of two diameters, having its smaller area constantly exposed to pressure fluid, a port communieating with the rear end of the cylinder and adapted to be uncovered by the smaller end of the valve when in one position, an annular valve groove between the smaller and larger diameters of the valve and in constant communication with the exhaust, a port conthe other valve groove.

nected' with the pressure fluid and opening into theenlarged portion of the valve chamher, an annular groove insaid valve adapted to register with said port ih'one position of the'valve', and a passage leading, to the forward end of the cvlinder, said passage in one position of the valve being placed in communication with said live pressure port, and in another position thereof in communication with the said exhaust passage.

4. A pressure fluid tool having a cylinder, a piston, a valve having two heads of difi'ercm diameter, a, valve block having a valve chamber open at its rear end to the pressure fluid, said'valve having its head ofsmaller diameter exposed tov the said pressure fluid, an annular oove in' said valve chamber connecting with the rear end of the cylinder and adapted to be placed in communication with the open end of-said valve block by the forward movement of the valve, an annular groove in the larger head of the valve, a live pressure port'and a cylinder port communicating with the forward end of the cylinder, said valve in its rearward position acting to place said pressure port and cylinder port in communication by way ofsaid annular groove-in the larger head of said valve.

' 5. A pressure fluid tool having a cylinder, a piston, a differential valve having two heads of difl'erent'diameter and two annular grooves, a valve block provided with a'valve chamber having an enlarged portion communicating with one end of said cylinder and a reduced portion communicating with the motive fluid supply,-' the larger head of the other port, and in the other position to cover the first port and open the other port to the exhaust by way of one valve groove and to open the other end of the cylinderto the motive fluid supply solely by way on 6. A pressure fiuid tool having a-cylinder, a piston, a differential valve having two heads of difi'erent diameter. an annular groove intermediate said heads and an annular groove in the larger head of said valve, a valve block provided with a valve chamber having an enlarged portion communicating with one end of said cylinder and a reduced portion communicating with the motive fluid supply, the larger head of'said valve working in the enlarged portion of said valve chamber and the smaller head working in the'reduced portionof said valve chamber, a

said valve workin in the enlarged portion 10 valve when ,in the other position acting to open such other end of the cylinder to the motive fluid supply by way of the annular groove in the larger head of said valve and to open the other chamber groove to the ex haust by Way of the intermediate valve 15 groove. a I

In testimony whereof I have signed my name to this specification.

GEORGE H. GILMAN.

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