US2082205A - Pressure fluid motor - Google Patents

Description

June 1, 1937. E. G. GARTIN PRESSURE FLUID MOTOR Filed Nov. 1, 1934 Elmer 660/4112 ,4 -,,4,

IN V EN TOR.

ATTORNEY Patented June 1, 1937 UNITED STATES PRESSURE FLUID MOTOR Elmer G. Gartin, Claremont, N. H., assignor' to Sullivan Machinery Company, a corporation of Massachusetts Application November 1, 1934., Serial No. 751,009

4 Claims.

This invention relates to pressure fluid motors, and more particularly to improvements in the control valve mechanism of such motors.

An object of this invention is to provide an improved pressure fluid motor. Another object is to provide an improved fluid distribution means for such a motor having embodied therein improved and simplified fluid distributing valve mechanism. A further object is to provide an improved fluid distributing valve mechanism having embodied therein improved throttle control means. Yet another object is to provide an improved fluid supply connection associated with the fluid distributing valve mechanism. Still another object is to provide an improved controlling mechanism for a percussive motor whereby a variable blow may be obtained. These and other objects and advantages will, however, hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustration one form which the invention may assume in practice.

In this drawing,

Fig. l is a longitudinal sectional view through ,the illustrative form of the improved pressure fluid motor.

Fig. 2 is a View similar to Fig. 1 showing the moving motor parts in a different position.

Fig. 3 is a detail sectional View taken on line Of Fig. 1.

Fig. 4 is an end elevational view of the valve chest element.

Fig. 5 is an elevational view of the fluid distributing valve.

In this illustrative construction there is shown a pressure fluid motor comprising a cylinder I having a bore 2 containing a reciprocatory hammer piston 3. The hammer piston has a piston head 4 fitting the cylinder bore and a forwardly projecting cylindrical striking bar 5 for deliverering impact blows to the shank of a suitable working implement 6, the striking bar being guided in a bore 1 formed in the front motor head 8. The working implement is supported within a suitable chuck 9 carried by a chuck housing H]. The rear end of the cylinder bore is closed by a rear head block II. The parts 8, l0 and II are held in assembled relation with respect to the cylinder in any suitable manner.

Now referring to the improved fluid distribution means, it will be noted that formed in the rear head member II is a transverse bore M arranged with its axis extending at right angles with respect to the cylinder bore axis, and arranged in this bore is a cylindrical valve chest element, l5 held therein by a screw plug it. Alined with the bore I4 is a reduced bore ll having arranged therein a cylindrical valve control member l8. Swivelly mounted in a conical bore l9 formed in the plug l6 and coaxial with (Cl. l2112) the valve chest bore is a fluid supply connection 26, and the plug It has an inner chamber 21 for receiving fluid from the connection 20 fromher 2| in the plug I6, while the inner wall of the bore It is annularly recessed at 25. The inner face of the member if; and the inner wall of the bore M are annularly grooved at?! and 28, respectively, these grooves being arranged concentrically within the outer recesses 24, 26. 'The groove 28 is connected to one passage 25 through a passage 29, while the recess 26 is connected to the groove 21- through a passage 30. Formed centrally within the member l5 and communicating with the valve chamber is a bore 3i connected through a passage 32 with a recess 33 communicating directly with the rear end of the cylinder bore. The valve control member is is provided with a central bore 34 communicable through a radial port 35'with an annular recess 38 surrounding the bore llfand this recessis connected through a passage 3? and port 38 with the forward end of the cylinder bore. The cyltra-lly located free exhaust port 39.

When the parts are in the position shown Fig. 1, pressure fluid may flow through the swivel connection 28, groove 2|, passages 25, recesses 24, through the valve chamber past the outer face of the valve 23, 'bore 3i, passage 32 and chamber 33 to the rear end of the cylinder bore, the pressure fluid acting on the'rear pressure area of the'motor piston to drive the latter forwardly to effectits working stroke, i. e.,'to deliver an impact blow to the shank of the working implement 5. wardly, the piston head l closes the central exhaust port-39, and upon continued forward movementof the piston, the rear edge of the piston head overruns the exhaust port 39, thereby con- I nesting the rear end of the cylinder bore to ex- I haust, and as a result, there is a material reduction in pressure in the valve chamber at the outer side of the valve. The constant pressure in groove 2? acting on the inner face of thevalvetogether with the compression pressure built up in cham As the motor piston moves forside of the valve, through the bore 34 in the valve I8, and through port 35, recess 36, passage 31 and port 38 to the forward end of the cylinder bore, the pressure fluid acting on the forward pressure area of the piston to drive the latter rearwardly. As the motor piston moves rearwardly the piston head closes the exhaust port 39, and upon continued rearward movement of the motor piston, the forward edge of. the piston head overruns the free exhaust port 39, thereby connecting the front end of the cylinder bore to exhaust; and as a result there is a material reduction in pressure in passage 31, bore 34 and in the valve chamber at the inner side of the valve. The constant pressure in groove 28 acting on the outer face of the valve, plus the compression pressure in chamber 3 I, overcomes the opposing reduced pressure and throws the valve inwardly from the position shown in Fig. 2 to the position shown in Fig. 1. These operations are rapidly repeated during normal operation of the motor. 7

Associated with the fluid distributing valve is the improved throttle control means comprising the valve control member l8. The member 18 is threaded at 43 within the head member ll and is provided with an operating handle 44. When it is desired to throttle the motor, the operator grasps the handle 44 and rotates the member l8, thereby moving the latter axially inwardly so that the inner end thereof engages the inner face of the valve 23, moving the valve tightly against its outerseat in the position shown in Fig. 2, the inner end of the member l8 at the same time having tight end surface contact with the inner surface of the valve. As a result, the distributing valve is held in the position in Fig. 2 while the inner end of the member l8 tightly engages the inner face of the distributing valve. The parts when in this position close oiT communication of the fluid supply passage 25 with the bores 3| and 34, thereby cutting oil supply of pressure fluid to the motor. When the memwill be provided continued operation ofxthe motor,

but with reduced force of blow, and a tendency toward shortstroking. It is true that there will be an increased constant pressure'difierential, so

to speak, at the left hand end of the valve, but

this will not be adequate to preclude the normal automatic operation of the valve, although it will vary the instant of movement of the valve from left to right position, as from that in Fig.

l to that in Fig. 2. Accordinglysince this increased differential area will speed up the throw of the valve with respect to the forward stroke of the piston, a very beneficial result. is obtained by my invention in the blow lightening function which can be obtaine'd'in the manner' described.

.As a result of this invention, it will be noted that an improved fluid distribution means is provided which is of an extremely simple design, the

improved fluid distribution means having associated therewith an improved fluid supply connection so that a substantially direct fluid supply to the valve chamber is attained. It will further be noted that by associating the throttle valve control element with the distributing valve the throttle controlling function of the motor is greatly simplified. Moreover it will be observed that a very simple and effectivemeans for varying the blow and the piston travel is provided. These and other uses and advantages of the improved pressure fluid motor will be clearly apparent to those skilled in the art.

While there is in this applicatian specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a pressure fluid motor, a cylinder having a piston reciprocable therein, and fluid distribution means for effecting reciprocation of said piston including a fluid actuated distributing valve, means for subjecting an area on said valve to a throwing pressure, and means for changing said efiective area on which the throwing pressure acts to alterthe time of valve throw.

2. In a pressure fluid motor, a cylinder having a bore, a piston reciprocable therein, fluid distribution means for effecting reciprocation of said piston including an automatic fluid actuated fluid distributing valve, throttle means associated with said valve and engageable with the latter to move said valve into a position to close completely the supply of pressure fluid past said valve to said cylinder bore, and abutment means relative to which said throttle means is adjustable for limiting movement of the valve'in opposite directions during the normal fluid distributing function of the valve and when said throttle means is moved out of the path of normal valve travel.

3. In a pressure fluid motor, a cylinder having a hammer pistonreciprocable therein, and fluid distribution means for effecting reciprocation of 'said piston including a fluid actuated fluid distributing valve, stop means for limiting movement of said'valve in opposite directions during its normal operation, and adjustable control means associated with said valveand movable relative to said .stop means, said control means engageable with said valve at one side thereof tributing valve, stop means for limiting movement of said valve during its normal operation, and adjustable control means associated with said valve and movable relative to said stop means, said control means engageable with said valve at one sidethereof to effect varied ranges of movement of said valve to control the force of the piston blow, one of said stop means having a central bore'and said control means being movable in said central bore.

ELMER G. GARTIN.

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