US2922396A

US2922396A - Pressure fluid motor

Info

Publication number: US2922396A
Application number: US560374A
Authority: US
Inventors: Walter D Fish
Original assignee: Joy Manufacturing Co
Current assignee: Joy Manufacturing Co
Priority date: 1956-01-20
Filing date: 1956-01-20
Publication date: 1960-01-26
Anticipated expiration: 1977-01-26

Description

Jan. 26, 1960 w. D. FISH PRESSURE FLUID MOTOR 3 Sheets-Sheet 1 Filed Jan. 20, 1956 INVENTOR:

WALTER D. FISH BY I ,2

ATTORNEY Jan. 26, 1960 w. D. FISH 2,922,396

PRESSURE FLUID MOTOR Filed Jan. 20, 1956 3 Sheets-Sheet 2 INVENTORI WALTER D. FISH AJ'TORNEY Jan. 26, 1960 w 11 s 2,922,396

PRESSURE FLUID MOTOR Filed Jan. 20, 1956 5 Sheets-Sheet 3 Fl G.6.

I NVENTORZ WALTER D. FISH BY MW ATTOBJL United States Patent PRESSURE FLUID MOTOR Walter D. Fish, Claremont, N.H., assignor to Joy lylanufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application January 20, 1956, Serial No. 560,374

8 Claims. (Cl. 121-29) This invention relates to pressure fluid motors and more particularly to a pressure fluid motor of the reciprocating piston type having improved piston controlled, fluid distribution means.

An object of this invention is to provide an improved pressure fluid motor which is more efficient in operation. Another object is to provide an improved pressure fluid motor having improved fluid distribution means. Yet another object is to provide an improved fluid distribution means for a pressure fluid motor having dual valves whereby increased power and greater economy in operation are achieved. A further object is to provide improved fluid distribution valve mechanism embodying dual fluid actuated valves provided with improved throwing passage arrangements whereby the valves are shifted into their diflerent operating positions in an improved manner. A still further object is to provide an improved fluid distribution means embodying improved fluid passage arrangement for supplying pressure fluid to the opposite ends of the motor cylinder.

These and other objects and advantages of the invention will hereinafter more fully appear.

In the accompanying drawings there are shown for purposes of illustration several forms which the invention may assume in practice. In these drawings:

Figs. 1 and 2 are central longitudinal sections taken through a preferred embodiment of the pressure fluid motor, showing moving parts in relatively diflerent positrons.

Fig. 2a is an enlarged fragmentary section taken on the plane of Fig. 2, showing details of the front distributing valve.

Figs. 3 and 4 are central longitudinal sections similar to Figs. 1 and 2, taken through a modified form of pressure fluid motor.

Figs. 5 and 6 are central longitudinal sections similar to Figs. 3 and 4, showing another modified construction.

In the several illustrative embodiments of the invention the improvements are incorporated in a pressure fluid motor of the valve-controlled, reciprocating piston type comprising a motor cylinder 1 having a bore 2 containing a reciprocable motor piston 3. A throttle valve 4 controls the flow of fluid under pressure from a suitable source to a chamber 5 in a rear head block 6 suitably attached to the rear end of the cylinder. A front housing 7 is suitably attached to the front end of the cylinder. Fluid actuated fluid distributing valve mechanisms 8 and 9 serve to control the flow of pressure fluid to the opposite ends of the cylinder bore to effect reciprocation of the motor piston.

The pressure fluid motor disclosed herein is desirably of the percussive type and the motor piston serves as a hammer and has a forwardly projecting striking bar 10 for delivering impact blows to the shank 11 of a conventional drill steel. The piston is intermittently rotated as it reciprocates in a manner well known in hammer rock drills and a conventional ratchet and pawl mechanism 12 has a rifle bar 13 provided with spiral grooves 14 I 2,922,396 Patented Jan. 26, 1960 ice,

slidingly interlocked with the spiral vanes of a conventional rifle nut, not shown, secured within the rearward portion of the hammer piston, the latter being made hollow at its rearward portion for receiving the rifle bar.

When the hammer piston moves forwardly to strike its blow on the steel shank the pawls of the ratchet mechanism slip freely over the ratchet teeth to permit the piston to strike an unimpeded blow on the steel shank and on the return stroke of the piston the pawls engage the teeth to hold the rifle bar stationary thereby causing a rotative motion to be imparted to the piston. This rotative piston motion is transmitted through stragiht grooves 15 on the striking bar 10 which are interlocked with straight vanes 16 within a conventional chuck nut 17 threadedly secured within a rotatable chuck sleeve 18 rotatably mounted within the front housing 7. The shank of the drill steel is suitably supported within and rotates with the chuck sleeve so that the drill steel is given a partial rotation upon each piston stroke. Since this intermittent rotation mechanism for the piston is well known further discussion thereof is unnecessary.

A front head 20 is fitted within a bore 21 of the forward portion of the motor cylinder and fitted within this head is a bushing 22 through which the piston striking bar extendsand in which the striking bar is rotatably and reciprocably guided. Fitted within the bore 21 within the rearward portion of the cylinder is a rear head 23 and a cylindric sleeve 24 is fitted within the bore 21 intermediate the flange of the front bushing 22 and the rear head 23 and the bore of this sleeve provides the bore 2 of the motor cylinder.

Now referring to the improved fluid distribution means of the preferred embodiment shown in Figs. 1 and 2 it will be noted that the valve mechanisms 8 and 9 each comprise a cooperating valve box and cover, the valve box and cover for the front valve mechanism being designated 25 and 26 while those for the rearvalve mechanism are designated 27 and 28. The

valve boxes

25 and 27 herein consist of integral parts of the front and

rear cylinder heads

20 and 23 respectively although evidently they may be made separable therefrom if desired. The pairs of valve boxes and covers cooperate to form annular

valve receiving chambers

29 and 30 in which

fluid distributing valves

31 and 32 are reciprocably mounted and these valves and valve receiving chambers respectively surround the piston striking bar 10 and the rifle bar 13, in the manner shown. The distributing

valves

31 and 32 are of the annular sleeve type and respectively have opposed faces which may be alternately subjected to the action of pressure fluid for effecting shifting of the valves into their different operating positions.

The distributing valves are herein desirably similar in design and each includes a cylindrical body 35 having at the end thereof nearest the cylinder bore an external flange 36 slidingly fitting a circular bore 37 of the valve receiving chamber. At the end of each valve body remote from the cylinder bore is an inwardly directed radial flange 38 having an axial cylindric sleeve like portion 39 slidingly engaging the inner circular wall 40 of the valve receiving chamber. The exterior surface of the cylindrical valve body fits the outer circular wall 41 of the valve receiving chamber. The heads which provide the valve boxes have outwardly and axially extending sleevelike portions 42 and 43 respectively eachhaving its exterior surface providing an inner wall of a valve receiving chamber and formed with an external flange 44 having its circular exterior surface contacting the inner surface 45 of the valve body. Each valve has an inner end surface 46 adapted to seat against a surface of the valve box and an outer end surface 47 adapted toseat against an outer end wall of the valvewreceiving chamber. The opposite faces 50 and 51 of the radial flange of each valve are adapted to be subjected to throwing pressures, and piston controlled throwing or

kicker passages

53 and 54 respectively communicate with the chamber-spaces at opposite sides of the radial flange 38 of the front valve and communicate with the cylinder bore 2 through

ports

55 and 56 respectively spaced apart longitudinally of the cylinder bore. A centrally located cylinder exhaust port 57 communicates with the cylinder bore at a point intermediate the

throwing ports

55 and 56. The throwing passage '53 communicates with an annular groove 58 on the exterior of the forward sleevelike projection 42 of the front valve box and a radial port 59 in the sleevelike projection connects the groove 58 with an annular recess 69 on the exterior of the bushing 22. A port 61 connects the recess 60 with the valve chamber at the forward side of the flange 4d. The throwing passage 54 communicates with the valve receiving chamber 29 at the extreme outer end of the latter at the forward end of the valve. The rear valve 32 has its chamber 30 connected by piston controlled

throwing passages

62 and 63 to ports 64 and 65 which communicate with the cylinder bore at longitudinally spaced points rearwardly of the cylinder exhaust port 57. The throwing passage 63 communicates with the space of the rear valve receiving chamber at the rear side of the valve flange 38 while the throwing passage 62 communicates with the space of the valve receiving chamber at the forward side of the valve flange 38 and at the rearward side of the flange 44. The piston head 66 is externally annularly grooved at 67 for alternately connecting the pairs of throwing passages to the exhaust port 57 as the piston reciprocates, in a well known manner.

The chamber in the back head 6 is connected by longitudinal supply passages 68 to an annular space 69 surrounding the reduced rearward portion of the valve box cover 28. Passages 70 in the cover 28 connect the space 69 with an annular recess 71 communicating with the rear valve receiving chamber 30. A shallow annular recess 72 in the rear head 23 communicates with the valve receiving chamber and communicates with passages 73 with the rear end of the cylinder bore. The

passages

68, 70 and 73 extend generally longitudinally of the motor so that a substantially straight flow of fluid to the rear end of the cylinder bore is obtained.

Also communicating with the annular space 69 is one or more passages 74 which at the forward end communicates with an annular recess 75 formed in the forward portion of the wall of the bore of the cylinder, and radial ports 76 in the front valve box cover connect the recess 75 with an annular recess 77 communicating with the front valve receiving chamber 29. An annular space 78 in the front head communicates with the rear end of the valve receiving chamber 29 and is connected by passages 79 with an annular recess 80 surrounding the reduced rearward portion of the front head 20. Passages 81 connect the recess 80 with ports 82 communicating with the front end of the cylinder bore.

When the fluid distributing valves arein the positions shown in Fig. 1, and the throttle valve 4 istopen as shown, pressure fluid may flow through passages 68 and inner space 69, passages 74, through annular recess 75, radial port 76, annular recess 77, past the rear end of the front valve and through annular space 78, passages 79, recess 80, passages 81 and radial ports 82 to the front end of the cylinder bore in advance of the piston head 83, the pressure fluid acting on the forward effective area of the piston head to drive the piston rearwardly to effect its return stroke. At this time the rear valve 32 is in its forward position with its front end seated against the rear valve box, cutting ofl fluid flow to the passages 73 and pressure fluid remains in the passages 70 and annular space 71. As the piston moves rearwardly the piston head first covers the exhaust port 57, and thereafter the port 56 of the throwing passage 54 is uncovered by the trailing edge of the piston head and pressure fluid may then flow from the cylinder bore through the throwing passage '54 to the valve chamber 29 at the forward side of the valve flange 38 to effect throwing of the front valve 31 from its forward open position to its rearward closed position shown in Fig. 2.

As the motor piston continues to move rearwardly the trailing edge of the piston head uncovers the port 64 of the throwing passage 62 to admit pressure fluid to the rear valve receiving chamber at the forward side of the flange 38 of the rear valve 32 to subject the latter to pressure fluid to eifect throwing thereof rearwardly to its closed position shown in Fig. 2, thus to admit pressure fluid from the annular space 71 through passages 73 to the rear end of the cylinder bore. The piston continues to move rearwardly by the expansion of the fluid in the front end of the cylinder bore and momentum to complete its rearward stroke and the trailing edge of the piston uncovers the exhaust port to connect the front end of the cylinder to exhaust.

As the piston approaches the rear end of its return stroke the fluid within the rear end of the cylinder bore is compressed by the piston to effect cushioning of the latter, and the fluid flowing to the rear end of the cylinder bore acts on the rear pressure area of the piston head to drive the piston forwardly to effect its working stroke.

-As the piston travels forwardly from the position shown in Fig. 2 the leading edge of the piston head first overruns the exhaust port 57 and thereafter the trailing edge of the piston head uncovers the port 65 of the throwing passage 63 to admit pressure fluid from the rear end of the cylinder bore to the rear valve receiving chamber at the rear side of the flange 38 of the rear valve to throw the latter forwardly to its closed position shown in Fig. l. The piston continues to move forwardly by momentum and expansion of the fluid within the rear end'of the cylinder bore and as the piston travels forwardly the trailing edge of the piston head uncovers the port 55 of the throwing passage 53 thereby to admit pressure fluid from the rear end of the cylinder bore to the front valve receiving chamber at the rear side of the flange 38 of the front valve to effect throwing of the latter forwardly to its open position shown in Fig. 1. As the piston continues to travel forwardly the trailing edge of the piston head uncovers the exhaust port 57 connecting the rear end of the cylinder bore to atmosphere. After the striking bar of the piston delivers its blow to the shank of the drill steel its leading edge enters a cushioning space at the front end of the cylinder bore so that the piston is cushioned as it reaches the forward end of its working stroke. The cycle of events above described is rapidly repeated during normal operation of the motor to eifect rapid reciprocation of the hammer piston thus to cause a series of impact blows to be delivered to the drill steel shank.

As the motor piston moves forwardly as above described and the front distributing valve is closed as shown in Fig. 2, fluid under pressure is retained in the passage or passages 74 so that when the valve is shifted forwardly to its open position shown in Fig. 1 pressure fluid flows to the front end of the cylinder bore. Thus by retaining live pressure fluid in the

supply passages

70 and 74, with no connection of these'passages with exhaust during motor operation, economy in fluid consumption is obtained as Well as greater speed and efliciency. Further the pair of separate throwing passages for each distributing valve results in a more positive and rapid valve action.

In the modified embodiment of the invention shown in Figs. 3 and 4 the motor cylinder and piston structure, the drill steel rotation means, and the fluid distribution means are essentially the same as those above described, with the primary exception that the dual distributing valves are both located at the rear end of the cylinder bore. Moreover, in this modified embodiment, the fluid supply passage or passages are intermittently connected to exhaust. The rear cylinder head 23 which provides the valve box 27' has an elongated rearward sleeve portion 85 surrounding an elongated rifle bar 13' and this sleeve portion extends axially within a bore 86 of an intermediate valve box member 87. A rear valve box cover 88 has a forwardly extending sleeve portion 89 surrounding a reduced rearward portion of the sleevelike portion 85, and the portions 85 and 89 respectively have external flanges 44 which have their peripheral surfaces in sliding contact with the inner surfaces of the bodies of the distributing

valve

31 and 32. The intermediate box member 87 has end bores 90 which provide the outer walls of the

valve receiving chambers

29 and 30, and exterior cylindrical surfaces of the valve bodies have sliding fits with these bores. The exterior surface of the sleevelike portion 85 provides the inner walls of the valve receiving chambers and the inner surfaces'of the sleevelike projections 39' have sliding contact with the inner chamber walls. Formed within the intermediate box member 87 are front and rear

annular spaces

91 and 92 and longitudinal passages 93 extend between and connect these spaces together. Longitudinal supply passages 68' conduct pressure fluid to the space 92 and through the passages 93 to the space 91. The partition 94 on the intermediate box member 87 extends inwardly between and separates the valve receiving chambers and has a bore 95 the walls of which have tight sealing contact with the exterior surface of the sleevelike portion 35. Pairs of throwing

passages

53, 54 and 62, 63 communicate with the cylinder bore at longitudinally spaced points in the manner of the embodiment described, for supplying throwing pressures to the opposed pressure areas of the valves to effect throwing of the valves into their different operating positions. These throwing passages communicate with the valve receiving chambers respectively at opposite sides of the radial flanges 38' of the valves for alternately subjecting the opposed pressure areas of the valve flanges to throwing pressures. A fluid supply passage or passages 74 connects the rear end of the rear valve receiving chamber with the front end of the cylinder bore and fluid supply passages 73' connect the front end of the front valve receiving chamber with the rear end of the cylinder bore. In this embodiment of the invention the motor piston opens the exhaust port 57 to connect the front end of the cylinder bore to atmosphere and the fluid in the supply passage or passages 74 is exhausted, contrary to the preferred embodiment first described. Otherwise the construction and mode of operation of this form of the invention are similar to those of the preferred embodiment.

In the modification shown in Figs. 5 and 6 the motor cylinder and piston structure, the drill steel rotation means, and the fluid distribution means are quite like those of the embodiment shown in Figs. 3 and 4. In this instance, however, the dual fluid distributing valves 31 and 32' vary slightly in axial section with the sleevelike portions of the valve elongated and movable into end abutting engagement so that either valve may engage and aid in the shifting of the other.

An annular recess 96 in the partition 94' of the intermediate box 87' receives the inner adjacent ends of the sleeve portions of the valves and this space is vented to atmosphere through a vent passage 97. Similar pairs of throwing passages 53, 54' and 62', 63' are provided for effecting throwing of the valves into their difierent operating positions as in the embodiment shown in Figs. 3 and 4. Otherwise this modified embodiment of the invention is similar to that of the modification shown in Figs. 3 and 4.

As a result of this invention an improved pressure fluid motor is provided having improved fluid distribution means whereby economy in operation and increased efliciency are obtained. By the provision of the improved valve throwing arrangement with the pairs of throwing passages for the distributing valves a more positive and quicker valve action is attained. By trapping live pressure fluids in'the fluid supply passages for the ends of the motor cylinder a more eifective and rapid operation of the motor is obtained. These and other advantages of the invention will however be clearly apparent to those skilled in the art.

While there are in this application specifically described several forms which the invention may assume in practice it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be 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. A pressure fluid motor comprising, in combination, a cylinder having a bore, a piston reciprocable in said cylinder bore, fluid distributing passages for conducting pressure fluid from a suitable source to the opposite ends of said cylinder bore for effecting reciprocation of said piston, fluid actuated fluid distributing valves for controlling the communication of said passages with said cylinder bore and when closed trapping live pressure fluid in said passages, and valve throwing passage means communicating with said cylinder bore at spaced points longitudinally of the latter and controlled by said piston as the latter reciprocates for alternately subjecting opposed pressure areas on each valve to pressures for throwing said valves into their open and closed positions.

2. A pressure fluid motor as set forth in claim 1 wherein said valve throwing passage means includes a pair of separate throwing passages for each valve for alternately subjecting opposed pressure areas on each valve to throwing pressures, and communicating with the cylinder bore at points spaced apart longitudinally of said cylinder bore.

3. A pressure fluid motor comprising, in combination, a cylinder having a bore, a piston reciprocable in said bore, fluid supply passage means for conducting pressure fluid from a suitable source to the opposite ends of said cylinder bore to effect reciprocation of said piston, fluid distributing valve means comprising separate fluid actuated fluid distributing valves respectively controlling the communication of said passage means with the ends of said cylinder bore, said valves each having opposed pressure areas, and valve throwing passagemeans including a pair of separate throwing passages for each valve, said throwing passages communicating with said cylinder bore at points spaced apart longitudinally of said cylinder bore and controlled by said piston as the latter reciprocates whereby live pressure fluid is conducted from said bore to the opposed pressure areas on said valves.

4. A pressure fluid motor comprising, in combination, a cylinder having a bore, a piston reciprocable in said bore, a cylinder exhaust controlled by said piston, a fluid supply chamber arranged rearwardly of said bore, fluid conducting passage means communicating with said supply chamber and including passages extending longitudinally of the cylinder for conducting pressure fluid to the opposite ends respectively of said bore to effect reciprocation of said piston, and fluid actuated fluid distributing valve means movable into open and closed positions for alternately eflecting communication of said passages with the opposite ends of said bore and controlled by said piston, said valve means located near the bore-ends of said passages and when closed cutting off communication of said passages with said bore while retaining live pressure fluid in said passages whereby communication of said passages with the cylinder exhaust is precluded.

5. A pressure fluid motor comprising in combination, a cylinder having a bore, a piston reciprocable in said bore, a cylinder exhaust controlled by said piston, a fluid supply, fluid conducting passage means communicating with said fluid supply and including passages extending longitudinally of the cylinder for conducting pressure fluid to the opposite ends of said bore to eifect reciprocation of said piston, fluid actuated fluid distributing valve means movable into open and closed positions for alternately effecting communication of said passages with the opposite ends of said bore, and valve throwing means controlled by said piston for admitting live pressure fluid from said bore to opposed throwing surfaces on said valve means for moving the latter into said open and closed positions, said valve means located near the bore-ends of said passages and when closed cutting ofl communication of said passages with said bore while communication of said passages with said fluid supply is maintained'whereby communication of said passages with the cylinder exhaust is precluded.

'6. A pressure fluid motor comprising in combination, a cylinder having a bore, a piston reciprocable in said bore, a fluid supply, fluid conducting passage means communicating with said fluid supply and including-passages extending longitudinally of the cylinder for conducting pressure fluid to the opposite ends of said bore to efiect reciprocation of said piston, fluid actuated fluid distributing valve means movable into open and closed positions for alternately effecting communication of said passages with the opposite ends of said bore, said distributing valve means comprising a pair of fluid operated distributing valves for respectively controlling the communication of said longitudinal passages with said cylinder bore, and valve throwing means controlled by said piston for admitting live pressure fluid from said bore to opposed throwing surfaces on said valve means for moving the latter into said open and closed positions, said valve throwing means comprising throw passages for admitting live pressure fluid from said bore to oppose pressure areas on said valves respectively, said valves when closed cutting ofl communication of said passages with said bore while communication of said passages with said fluid supply is maintained whereby said valves when closed trap fluid in said longitudinal passages when communication of the latter with said bore is interrupted.

7. A pressure fluid motor as set forth in claim 6 wherein said throwing passages respectively communicate with said cylinder bore at points spaced longitudinally of the latter with said throwing passages respectively communi eating with opposed ends of said valves.

8. A pressure fluid motor comprising, in combination, a cylinder having a bore, a piston reciprocable in said bore, a cylinder exhaust controlled by said piston, a fluid supply chamber arranged rcarwardly of said bore, fluid conducting passage means communicating with said supply chamber and the opposite ends of said bore to eflect reciprocation of said piston including a fluid conducting passage extending longitudinally of the cylinder and communicating with the front end or" said cylinder bore, and fluid actuated fluid distributing valve means movable into open and closed positions for automatically effecting communication of said passage means with the opposite ends of said bore and controlled by said piston, said distributing valve means including a fluid distribution valve located near the bore-end of said passage and when closed cutting off communication of said passage with said bore while retaining live pressure fluid in said passage whereby communication of said passage with said cylinder exhaust is precluded.

References Cited in the file of this patent UNITED STATES PATENTS 460,617 Williams Oct. 6, 1891 475,910 Williams May 31, 1892 959,547 Ketterer May 31, 1910 1,068,649 Hansen July 29, 1913 1,770,676 Smith July 15, 1930 2,011,424 Smith Aug. 13, 1935 2,016,124 Smith Oct. 1, 1935 2,307,847 Morrison Jan. 12, 1943 2,675,784 Gunning Apr. 20, 1954 FOREIGN PATENTS 321,674 Great Britain Nov. 15, 1929