US1250932A - Pressure-fluid motor. - Google Patents

Description

G. H. GILMAN.

PRESSURE FLUID MOTUR. APPLicATmN msn MAR. so. w14.

1,250,932. Patented De@ 18, 1.917..

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Georgen Gzllwnan,

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GEORGE H. GILMAN, 0F CLAREMONT, NEW HAMPSHIRE, ASSIGNOR T0 SULLIVAN' MACHINERY COMPANY, 0F BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

. PBESSUREFLUID MOTOR.

Patented Dec. 1s, 1917.

Application led March 30, 1914. SeriaI No. 828,155.

To all whom 'it may concern:

Be it known that I, GEORGE H. GILMAN, a citizen of the United States, and a resident of Claremont, Sullivan county, New Hampshire, have invented an Improvement in PressureFluid Motors, of which the following description, in connection with thenccompanying drawings, is a specification,l like characters on the drawings representing like parts.

My invention relates to pressure fluid motors, which may be of the impact ty e, and more particularly to the valve mec anism for controlling the admission of the motive fluid to and exhaust from the'eylinder.

My invention will be best understood by.`

reference to the following specification, lwhen taken in connection with the accompanying drawings of one illustrative embodiment thereof, while its scope will be more particularly pointed out in the ap pended claims.

In the drawings:

Fi ure 1 is a central, longitudinal sectiona view, partly broken away, of a pressure fluid impact' motor embodying one form of my invention;

Fig. 2 is a sectional view, partly broken awa', on line 2--2 of Fig. 1; y,

Figa 3 is a sectional view on line 3'-3 of Fig. l; and

Figs. Ll and 5 are diagrammatic sectional views, in which all of the ports and passages are brought into one plane, the better to illustrate the action of themotor; Fig: i showing the piston in its forward position and the valve in its rearward position; and Fig. 5 showing the piston in its rearward position and t e valve in its forward position.

Referring to the drawings, and to the em.- bodimentoflmy invention which I have selected for illustration, l have there. shown a' pressure `fluid motor having a cylinder 6, in which a'1` piston 7 reciproca'tes,.:'1`.his piston may be, and in the-Presentyfinstance is,

provided with a forwardly projecting-reduced portion 8, which may constltut'e a' piston rod to be connected to the working device to be actuated, or the reduced portion ma be used as a hammer to deliver a sueces-"o1i of blows against any suitable impact receiving member, which 1t is unnecessary herein to illustrate, as it forms noessentia part of my present invention.

The movements of the iston are controlled by a controlling valve 9, herein in the form of acylindrical shell located in a valve chamber, herein disposed at the rear of the cylinder4 chamber, and in line therewith, such valve chamber being' herein provided by a two-part valve block composed of a forward section 10 and a rear section 11. Both sections of the valve block are seated within the walls of a suitable casing 12, which-projects from a head-block 13,'

the rear portion of the latter bein broken away. The head-block is provided with a supply chamber 14 forthe. motive lfluid, to which the latter is constantly 'admitted from any suitable source of supply through a suppli1 passage 1'5. or the admission of motive fluid to the of 1 the cylinder chamber, thev valve chamber is provided with 'an annular admission groove 16, which has constant lcommunicaton with the supply chamber 1 4, through a rearwardly extend' g passage or passagesv 17.w i

`Zllhen in its rearward positioi (see Fig. 5), the rear end of the valve enters that portion of the vaelve chamber behind the admisrior of the valve andthe rear of the cylinder chamber yfrom theniotive fluid. In the forward position of the valve, however (see 1 Figs. 1 and 4), the interiorof the valve-is opened 'freely to theladmissio'n groove 16, so that the motive fluid flows freely to the interior of the valve, andthence to the rear of the cylinder .chamber to drive the piston forward.

The forward end of the c linder chamberl is supplied with motive lui when the valvii'v is at its rearward position -(see Fig. 5), by means of,A oneuor more, herein two, return pressurepasspges 18 which extend longitudmally 'througlwthe walls of the cylinder and open this passage extends through the valve/block section 10, andterminates in a lateral port 2 0 formed in the valve block 11 and opening into an annular valve block oove 21.

-. In the rearward position o? the valve, the groove 21 is connected with the motive fluid supply by mcansof a circumferential valve groove 22, the admission groove 16 into the cylinder chamber" y Athrough a laterallpbrt 19. At its rear end,

li co being cut away at 23., adjacent one or more of the admission passages 17 (see Figs. 1,

4 and 5), so as to give a sufficiently free admission of motive fluid to the groove 21, by way of the valve groove 22, to return the piston. From the groove 21, the motive fluid passes through the port 20, passages 18 and port 19, to the forward end of the cylinder.

To exhaust motive fluid from the rear of the cylinder chamber, there is provided in the valve block a `lateral exhaust port 24, which-opens into the valve chamber. This lateral exhaust port lcommunicates with one or more, herein three, longitudinal'exhaust passages 25, formed partly in the cylinder` walls and extending rearwardly through y yboth sections of the valve block, and comential enlargement 27 workingY in an annumunicating witha. permanently open exhaast-port, or ports, 26 formed in the headblock.

The valve is;provide'd with a circumfer- A' lar chamber or groove 28 of the valve chamber,l the valve block being` provided with a, `lateral exhaust vport 2f) -leading from said groove to the exhaust passage 25. When the rvalve is in its rearward position (see Fig. 5), a prolonged portion 30 of the valve which extends" beyond -the circumferential enlargement 27, lifts from its seat suiliciently to open the rear-of the cylinder chamber'toy the forward end of the valve chamber, thus placing the rearof the cylinder chamber in communication with the exhaust port 24. As shown in the drawin s, the port 24 is only partially uncovered y the valve when inthis position, but such port may be, and

preferably is, of an elongated cross section (see Fig. 2), sothat by suitably proportionin the port, the exhaust from the rear of the cy index-. chamber niaybe made as free or restricted asA desired.

. fTo exhaust motive fluid from the forward end of the cylinder chamber,. the latter is provided with an exhaust port 31, adapted to, be uncovered by the piston before the completion of the rearward movement there-` of, such port being connected with the longitudinal exhaust vpassages 25, and thereby with the atmosphere'. through the Perma-- nently open exhaust opening 26. In addition to this, the forward end of the cylinder is maintained open for the exhaust of mtive fluid during the forward movement of the piston, after the closure of the port 31 through the return port 19, passage 18, and port 20, the latter being connected through the valve chamber, lwhen the valve is posi,- tioned as shb'iwn in; 4, with the valve groove 22, chamber, 28, and exhaust port 29,

ReferringA now more particularly to the provision for moving the valve to reverse the piston, 'the valve is provided with a rear en d portion 32 of slightly reduced diameter having a sliding fit in the corresponding reduced portion r33 of the valve chamber, be:

lup'to the time when it reaches the port 38,

yond the admission groove 16. This leaves a small, circumferential shoulder 34, which constitutes a small pressure area constantly exposed to the motive fluid in the admission roove 16. On the other hand, the forward ace ofthe circumferential enlargement 27 constitutes an op osing differential pressure area, of relative y greater proportions.

When the valve is in its forward posi-- tion (see Figs. 1 und4), the same is maintained in such position during the forward movement of the piston by the pressure on the small area 34, augmented by 'the pressure onthe rearendarea 35-of the valve, there being no substantial pressure against the larger opposing 'pressure area' in the forward end of the chamber 28. To insure the absence of substaptial pressure against this larger area at this time, there is herein provided a lateral port 36 leading from the forward end ofthe chamber 28 to a longitudinal passage 37, extending forwardly through the cylinder wall, and having at its forward end a port 38, which is in com- 'the cylinder cham er with the exhaust port 31 and exhaust passage 25 leading to the pp'rlmanently open exhaust opening 26. en the piston is moving forwardly, and

the port 36, passage 37 andport 38, serve to exhaust any pressure fluid trapped ,in the forward end of the chamber 28,.or entering thereinto by leakage fromY the cylinder chamber.

lVhen, however, the piston, during its forward stroke, passes beyond and cuts the port 38 off from communication with the exhaust port 31, the passage 37 and port 36 are utiized to supfplyl pressure fluid to the forward end area' o t e enlargement 27, to cause a reversal of the valve. To this end, the passage 37 is provided with'a lateral port 39, to 'which it will be convenient to refer as the intermittent pressure port, for the reason that pressure fluid is intermittently supplied thereto to cause the reversal of the valve. Located substantially in line witlithis intermittent pressure port, is a constant pressure port 40, the latter communicating constantly 1 1b throu h a longitudinall passage 41 and latera port 42 with one of the rearwardly extending passages 17 leading to the constant pressure space 14.

As a means for intermittently establishing communication between the constant pressure port 40 and the intermittent pressure port 39, the piston is herein provided with a passage, herein in the form of an annular roove 43, which is so positioned that when This may take place at any suitable point, but preferably occurs just prior to the strikinfr-of the blow. 'Ifhe reversalv of the valve talies place, owing to the fact that the pressure upon the large opposing differential area exceeds that'on the small area 34 plus the end area 35 of the valve, and thus causes the latter to be quickly shifted to the position shown in Fig. 5. As above described, this admits motive fluid to the forward end of the cylinder chamber, and opens the rear end thereof to the exhaust so that the-piston, having made its working stroke, moves back on its return stroke. V

The piston carries, projecting from its 'rear` end, a plug portion 44, which in the illustrated embodiment of my invention, is of "lesser diameter' than the piston itself. This plug portion is ada ted to project out an Iaperture 45 in the valve 'it preferabl of'and beyond the cylin er chamber in the rearward position of-the4 valve, andthrough lug, in which has` a` lsliding t, and which constitutes `t e means of communication be- 't'ween th'ewvalve chamber. and the piston chamber,`

The valve. having been reversed, the pis ton during its returnmovement expels the exh'austmotivefluid at the rear of the cylin- 4der chamber, through ,the exhaust port 24.

` During this movement of the piston, the-supply of motive 'fluid'to the chamber 28 is continued for a time, or-until the forward edge of the pion `glroo've' 43 has passed rear-- wardly beyond t e intern'iittentl pressure port 39, thus cutting olf the latter from the constant pressure port 40. Air under pressure is now trapped 'in the passage. 37, port 36, and chamber 28, which, acting against the forward area of the enlargement 27 and in conjunction with the' exhaust pressure acti ing on the forward end of the reduced portion 30 'of the valve,'continues to hold the latter in its rearwardpositiom When, however, the forward end of the piston, in its rearward travel, reaches the intermittent pressure port 39, the latter is placed in communication with the forward exhaust port v the portion 44 entering the same.

31, whereby the pressure on the large differential area of the enlargement 27 of the valve is exhausted.'

' The valve is thus held reversed preferably after the plug portion 44 enters the aperf ture 45. When the piston, however, reaches some such position as is represented in Figs. 1 and 4, (the valve still'being in the posi'- tion' shown in Fig. 5), a fluid cushion is formed between the endv of the piston and the opposing face' of the valve block, by reason of the closure of the apex-ture 45 by This brings the piston to rest, and prevents, it from striking the valve block. should the valve Vfail to reverse. About the s-.une time, however, the remaining motive fluid having Leccese b also opened to the exhaust valve through the chamber by way of the port 19, return passage 18, port.20, valve groove 22, chamber '28,' and port 29, this condition holding until the valve is again reversed. ,The valvewhen reversed, is securely held-in its forward po Sitio'n, since the. port 36, passage 37, and port 38, relieve the larger pressure area of the pressure Vof any accumulated motive fluid.

lVhile the length Aof the projecting '.plug portion 44 might be reduced'so as not to project within the valve in the rearmost po sition ofthe piston, herein, for` the ksake of reducing the clearance within the valve chamber, it is somewhat prolonged as Shown in the drawings, so that it not only passes through and closes the port-like aperture 45, but also enters part wayV into the valve itself. The interior diameter of the valve, however, is made sli htly greater than the exterior diameter o the plug, so that a small clearance space remains between the valve and the entering portion of 'the plug. This permits the motive fluid trapped within the valve chamber to escape back and about the sides of the plug to the exhaust port 24,'

when the plug enters the valve. Such escape, moreover, may be facilitated, if desired.

by any suitable formation of the plug, such for example as the provision of one or more longitudinal grooves 46, cut part Way along the surface of the plug. These grooves, moreover, have another function which is of considerable importance. starts upon its forward movement, motive fluid acts against the area of the plug 44, but when the forward ends of Vthe grooves 46 pass forwardly beyond the aperture 45 and enter the rear portion of the cylinder chamber, the latter immediately receivesimotive fluid through lthe grooves, and such motive fluid at oice acts upon the full area of the pist-on,'tl1e1'cby insuring a quick and powerful action at the part o'l the stroke where it is most needed. 'V

The desvribed foi-rn of valve, being 'very delicately balanced, acts quickly to reverse at the close of the rearward'piston move ment, so that a very high speed and very powerful blow can be secured through ils,

When the piston the cylinder and valve chamber being reduce to a minimum, a very high elliciency can be obtained.

It will be observed that the valve being located in a separate chamber, behind the piston chamber and between the latter and the head-block, it is not necessary for the operation of the tool that any part of the piston enter the valves. Herein, the plug 44, carried by the piston, is caused to enter the valve chamber 'to reduce the clearance therein, but sucli is not essential. The clearance within the. valve chamber might be reduced by making the valve solid except for a central axial passage through the same, or with a valve proportioned as. shown,- a stationary plug might be employed projecting forwardly within.- the valve'from thc valve block section 11.

While I have herein shown and described one specific embodiment of my invention for illustrative purposes, and have disclosed and discussed in detail the construction and arrangement incidental yto one s ecific application thereof,` it is to be un erstood that the invention is limited neither to the mere` pressure area, a forwardextensionextending forwardly from the larger pressure area; means for supplying motive fluidconstantly to said smaller area; a chamber in which the larger annular projection works; means ncluding a constant pressure port, an int-ermittent pressure port, a passage leading from said intermittent pressure port to-said chamber, anda piston having a groove to connect said ports for intermittently supplying motive fluid to and exhausting it from said chamber thereby to lcause the. larger pressure area intermittently to predominate over the smallerthereby to e'ect the reversal of the valve; means for supplying motive fluid to the interior of said valve at its rear end to drive said piston forward; means conports 2 4 and 29.

trolled by said valve t0 exhaust the rear end of said piston during its rearward'stroke.

2. A pressure fluid motor having an ani nular valve provided with differential presfor supplying motiverfluid to the interior of said valve at its rea-rV en d to drive said piston forward; means'controlled `by said valve for .supplying motive fluid to the forward end of Said piston to drive. it rearward; means to exhaust the forward end of the piston duringa part ofits forward stroke; means controlled .by said valve to exhaust the forward end of said piston.during a. remaining'part oiits forward stro-ke; and means controlled by said valve to exhaust the rear end of said piston. during its rearward stroke.

A, 3. A- pressure fluid im act motor having a hollow valve9 provide with the enlarge ments 27 ,and 34 and the forwardand rearward extensionsythe piston 7 provided with the groove .143; and the cylinder provided with the consta-nt pressure space 14; the

A,valve chamber with its extension 133; the

groove 28 in whigh the enlargement works; the passage 37 with its ports 36, 38 and 39; the paage 18 with its ports'19and'f20'; the passage 4l with its port 40; theexli'aust passage'25 lwith its portV 31; and the exhaust 4. A pressure fluid motor havin a piston anannular valve rovided with differential ressure areas, a orward extension extend-a.. mg beyond the larger pressure area, a rearward extension extending beyond thesmaller pressure area, a pocket 33`for' s aid rearward extension; means for supplyingmotive fluid constantly to said smaller areaglineans including a constant prsure port, an intermittent pressure port and a groove 43 'in said piston to connect said ports Vfor intermittently supplying motive fluid to and eX- hausting it from said larger pressure area; means for supplying motive fluid Vto the interior of said valve at its rear 'end to vdrive said'piston forward; means controlled by said valve'for supplying motive fluid to the forward end of said piston to drive it rearn ward; means to exhaust the forward end of' the piston; and means controlled by sai valve to exhaust the rear end of sai-id piston during its rearward stroke. a u

5. A lpressure .fluid motor having: a pis- .am annular valve provided with differ Jal pressure arcas, a forward extension lending beyond the. larger pressure area,

larger pressure area; 4motive fluld to the interior of said valve at a rarward extension extending beyond the smaller pressure area. a pocket 2&3 for said rearward extension; means l'or supplying motivi` fluid constantly lo said smaller area; means including a constant pressure port. au intermittent. pressure port and a groove 43 in said piston to connect said ports for intermittently supplying motive fluid to and exhausting it from said larger pressure area; means for supplying motive fluid to the'interior of said valve at its rear end to drive said piston forward; means controlled bysaid valve for supplying motive fluid to the forward end' of said piston to drive it rearward; means controlled bysaid valve to exhaust the forward end of the piston; and means controlled by said valve to exhaust the rear, end of' said piston during its rearward stroke. i

(i. A pressure fluid motor having a plston posed extension; an annular valve surrounding said reduced rearwardly disposed extension and provided with differential pressure areas, a fbi-ward extension extending beyond the larger pressure area; means for supplying motive fluid constantly to the sm'aller'area; means' including!` a constant pressure port, an intermittent pressure port and a groove 43 in said piston to connect said ports for tive fluid to and exhausting it from said means for supplying its rear end to drive said piston forward; means controlled by said valve for Vsupplying'nlotive fluid to the forwardend of said piston to driveit rearward; means to exhaust the forward end ofthe piston; and meaus'controlled by said valve to exhaust the rear end of said piston during its rearward stroke.

7.A Alpressure fluid motor having a uiston; antannular valve provided with di erential pressure areas, a forward extension extending beyond the larger pressure area, means for supplying motive fluid constantly to the smaller pressure'area; means inclu ing a constant pressure port, an intermittent pressure port, and a groove 43 in said piston to connect said ports for intermittently supplying motive fluid to and exhaustmg it from said larger pressure area; a constantly open exhaust port for exhausting such pres- `piston during its provided with a, reduced rearwardly disintermittently supplying mo-v sure fluid as is opposed to shifting of said valve by pressure on said larger pressure area; means for supplying motive fluid to the interior of said valve at its rear und to drive said piston folnvard; means conti-oiled by said valve for supplying motive Huid to the forward end of said piston to drive it rearward; means to exhaust the forward end of -the piston; and means controlled by said valve to exhaust. the rear end of said rearward stroke.

8. A pressure uid motor comprising in kombination a cylinder, a piston therefor haying a rearwardly extending reduced ,pertion,an annular valve bavinga longitudi nally4 disposed opening therein into which said reduced portion ente-rs during a portion of the return stroke of said piston. and live pressure fluid actuated means for moving said vulve alternately into two .positions and for holdingsaid valve in each of said positions pending reversal of s id valve by said live pressure fluid actuate means.

' tt. pressure fluid impact motor having a piston;

means to cause said valve. tn abe moved in 'opposite directions by live pressure fluid:

its cylinder; an annular valve;

means for closing the' rear en d of said valve inits real-most position; means for causing 't motive fluid topass through said valve to drive saidpiston forward"when said valve is in it-s forward position; means under the control of said valve for exhausting the motive fluid from the. rear of said`piston; means for exhausting `the motive. fluid from the front end ofsaid piston -during a portion of its forward stroke-ilu-.huling au exhaust. portin `the main Vall of tin` cylinder independent of said valve-and adapted t'o be closed by said piston during the forward stroke thereof; and supplemental Vmeans under the control of said valve for exhausting the motive Huid from the front end of said piston after the closure of said exhaust port during a remaining portion of the forward stroke of. said piston.

In testimony whereof, I have signed my name to thisspecifcation, in the presence of two subscribing witnesses.

GEORGE H. GILMAN.

Witnesses:

C. J. JONES, G. H: JENKS.

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