US3927690A

US3927690A - Pressure fluid valve having fully opened, fully closed and restricted flow positions

Info

Publication number: US3927690A
Application number: US475499A
Authority: US
Inventors: Nils Axel Agren
Original assignee: Atlas Copco AB
Current assignee: Atlas Copco AB
Priority date: 1973-06-18
Filing date: 1974-06-03
Publication date: 1975-12-23
Anticipated expiration: 1992-12-23
Also published as: SE7308558L; SE391665B; GB1428582A; DE2428767A1; CA1012525A

Abstract

A power operated pressure fluid valve for controlling the impact power of a rock drill by establishing not only fully opened and fully closed positions, but also a restricted flow position. The valve comprises a main valve body which is transversely movable into the through-passage of the valve for blocking the through passage, and an auxiliary valve body movable within a coaxial bore of the main valve body for controlling transverse, restricted flow openings in the main valve body. The valve bodies are activated into their fully closed positions by pressure fluid introduced into a power cylinder surrounding their rear ends.

Description

United States Patent Agren PRESSURE FLUID VALVE HAVING FULLY OPENED, FULLY CLOSED AND RESTRICTED FLOW POSITIONS Primary Examiner-Arnold Rosenthal Attorney, Agent, or Firm-Flynn & Frishauf [75] Inventor: Nils Axel gren, Nacka, Sweden [73] Assignee: Atlas Copco Aktiebolag, Nacka, [57] ABSTRACT Sweden A power operated pressure fluid valve for controlling [22] June the impact power of a rock drill by establishing not [2]] Appl. No.: 475,499 only fully opened and fully closed positions, but also a restricted flow position. The valve comprises a main valve body which is transversely movable into the [30] Fomgn Apphcanon Pnomy Dam through-passage of the valve for blocking the through June is, I973 Sweden.............................. 7308558 passage and an auxiliary valve movable within a coaxial bore of the main valve body for controlling US. e1 transverse restricted flow openings in the main vaive Int. Clbody The valve bodies are activated into their o 60], closgd positions pressure introduced into a power cylinder surrounding their rear ends. [56] References Cited UNITED STATES PATENTS 10 Claims, 1 Drawing Figure 3.18.1772 6/l965 Hanson. Jr l37/599.2

U.S. Patent Dec. 23, 1975 7 w 2 m6 9 w A W 3 VI w I 5 0 E M7// m n n u.

PRESSURE FLUID VALVE HAVING FULLY OPENED, FULLY CLOSED AND RESTRICTED FLOW POSITIONS This invention relates to a pressure fluid valve, particularly intended for controlling the impact power of pneumatic rock drills, comprising a main valve body extending into a through-passage of the valve, which main valve body is operated by a control piston axially movable within a power cylinder.

SUMMARY OF THE INVENTION The object of the present invention is to provide an improvement in power controlled valves of the above mentioned type. The improved valve of the present invention not only has a closed and an opened position, but also a further position for limited or restricted passage of pressure fluid. When applied on rock drills, the additional, restricted fluid passage position makes it possible to carry out an automatic and remotely controlled drill start operation.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE shows a valve according to the invention being in a position for limited pressure fluid passage.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENT For facilitating the understanding of the invention reference is made to Swedish Pat. No. 301,939 corresponding to U.S. Pat. No. 3,381,761, issued in the name of Hansson which discloses an automatic flow cutting down valve connected to a rock drill for controlling the power supply thereto. The valve shown is able to occupy an opened and a closed position only. By this the present invention, a valve of this type is further developed into a three-position valve.

The pressure fluid valve shown in the FIGURE is provided with a housing I having an inlet 2 for pressure fluid, for instance pressure air, a through-passage 3 and an outlet 4. The latter may be connected to a pressure fluid consumer like a rock drill by means of suitable hoses. A power cylinder 5 constitutes a part of the valve housing 1 and accomodates sealingly and slidingly a main control piston 6. The control piston 6 is associated with a main valve body 7 which extends transversely into the through-passage 3 of the valve housing I and seals axially against a packing member 8 mounted in the through-passage 3. The main control piston 6 is provided with axially opposed seal rings 10 and II between which there is a reduced piston part defining an annular space I2. The power cylinder 5 is provided with a rear end wall I3 having a pressure medium inlet 14 which communicates with the power cylinder 5 through an abutment member 15 which is provided with suitable openings.

Throughout the control piston 6 and the main valve body 7 there extends a coaxial bore I8 which comprises two rear, step-wise widened

portions

17 and 16 and a forward large-diameter cavity 29. The coaxial bore 18 accommodates slidingly and sealingly an auxiliary valve body 21 which has a rear widened end portion 20 for sliding cooperation with the widened portion I6 of the coaxial bore I8. At its forward end as well as its rear widened end portion 20, the auxiliary valve body 2I is provided with seal rings which define an annular space between the coaxial bore 18 and the auxiliary valve body 21. This space is mainly constituted by the widened

portions

16 and 17 of the coaxial bore 18.

In its forward end position, the auxiliary valve body 21 is arranged to cover opposite transverse openings 22 in the main valve body 7, which openings define a restricted flow passage through the valve when being uncovered, as in the position shown in the FIGURE. Further, the coaxial bore 18 accomodates a helical spring 23 which acts between a backwardly facing shoulder 24 of the bore 18 and the rear widened portion 20 of the auxiliary valve body 21 for biasing the latter toward its rear end position. The rear end position of the auxiliary valve body 21 (illustrated in the FIGURE) is defined by a stop ring 25 mounted at the rear end of the coaxial bore 18. In this position the openings 22 are uncovered.

The power cylinder 5 is provided with a centrally located pressure fluid inlet 27 which communicates with the reduced piston part 12 of the control piston 6 and pressure fluid is suppliable to the coaxial bore 18 via a radial bore 28 in the control piston 6. Within the auxiliary valve body 21 there is arranged a passage 30 through which the widened

parts

16 and 17 of the coaxial bore 18 communicates with the front end of the auxiliary valve body 21. The passage 30 comprises a spring biased check valve 32 which opens for pressure fluid passage in a direction toward the front end of the auxiliary valve body 21. Into the auxiliary valve body 21 there is threaded a filter plug 33 which constitutes an abutment for the spring 31 of the check valve 32.

The forward end 34 of the power cylinder 5 communicates with the atmosphere through a connection nipple 35.

When the inlet I4 of the power cylinder 5 is supplied with pressure fluid, the control piston 6 is moved into the position shown in the FIGURE, whereat the through-passage 3 is fully closed. As will be hereinafter described in greater detail, the auxiliary piston 20 then is in its forward position wherein the auxiliary valve body 21 covers the transverse openings 22 and thereby fully blocks the through-passage 3. Now, if a pressure impulse is applied through the inlet 27 of the power cylinder 5, the widened parts I6 and. 17 of the coaxial bore 18 are pressurized via the reduced piston part 12 and the radial bore 28. Through the passage 30 of the auxiliary valve body 21 and the check valve 32 the pressure within the widened portion 16 and the forward end of the coaxial bore 18 is simultaneously equalized. Thus, the pressures acting upon the the opposite ends of the auxiliary valve body 21 are balanced and the helical spring 23 pushes the auxiliary valve body 21 back to the position shown in the FIGURE. The openings 22 of the main valve body 7 are then opened for restricted fluid passage. Then, a rock drill connected to the outlet 4 is able to be operated by a reduced power supply as drilling of another hole is stated. As the power cylinder 5 is depressurized or evacuated at the inlet 14, the pressure acting within the forward end of the coaxial bore 18 and the cavity 29 forces the auxiliary valve body 21 backwards (i.e., upwards in the FIGURE), while the main valve body 7 remains in its through-passage 3 blocking position sealingly engaging the packing member 8. When the auxiliary valve body 2] has reached its rear end position it abuts against the stop ring 25 and starts retracting the main valve body 7. As the latter is separated from the packing member 8,

pressure fluid gets access to its front end and drives the main valve body 7 back into the power cylinder 5. The movement is concluded in that the abutment member pushes the auxiliary valve body forwards relative to the backwardly moving control piston 6. The openings 22 are then reclosed by the auxiliary valve body 21 as the control piston 6 is stopped by the end wall 13. In this valve position the through-passage 3 is fully opened and the pressure fluid consumer, the rock drill, con nected to the outlet 4 receives full power. As the auxiliary valve body 21 is pressed into the main piston 6 the

coaxial bore portions

16 and 17 are depressurized through the inlet 27.

At resupply of pressure fluid to the inlet 14, the main valve body 7 reenters the through-passage 3 and abuts sealingly against the packing element 8. As the rear end of the coaxial bore 18 is depressurized through the bore 28, the annular space 12 and the inlet 27, the auxiliary valve body 21 remains in its forward position relative to the main valve body 7 during closing of the valve.

What I claim is:

1. Pressure fluid valve for controlling the impact power of pneumatic rock drills by selectively establishing a closed, a substantially unobstructed fully open and a restricted flow passage, comprising:

a housing having a power cylinder 5 and a throughpassage 3 for pressure fluid;

an elongated main valve body 7 movably mounted in said housing and being transversely movable between a rear position in which said through-passage 3 is fully and substantially unobstructedly opened, and a forward position in which said through-pas sage 3 is blocked;

a control piston 6 reciprocably guided within said power cylinder 5 and coupled to said main valve body 7;

said main valve body 7 being provided with a transverse, restricted flow passage 22 and a coaxial bore 18 extending axially throughout said main valve body 7;

an auxiliary valve body 21 reciprocably guided within said coaxial bore 18 of said main valve body 7 for movement between a position covering said restricted flow passage 22 and a position uncovering said restricted flow passage 22;

said control piston 6 having an opening at its rear end portion communicating with the rear end of said auxiliary valve body 21; and

a pressure fluid inlet 14 at the rear portion of said power cylinder 5 through which pressure fluid is suppliable onto the rear end of said control piston 6 and the rear end of said auxiliary valve body 21 for moving said main valve body 6 into its throughpassage 3 blocking position and said auxiliary valve body 21 into its restricted flow passage 22 covering position.

2. Valve according to claim 1 wherein said housing includes control means 27,28,30 coupled to said auxiliary valve body 21 for selectively moving said auxiliary valve body 21 relative to said main valve body 7 to uncover said restricted flow passage 22 when said through-passage 3 is blocked.

3. Valve according to claim 1 wherein:

4 said control piston 6 has two axially spaced seal rings 10,11 defining a first annular space 12; said power cylinder 5 has a generally central fluid inlet opening 27 therein so disposed as to remain in constant communication with said annular space 12 between said seal rings 10,11; said auxiliary valve body 21 has two axially spaced seal rings defining a second annular space 17 with said coaxial bore 18 of said main valve body 7; said control piston 6 has a generally radial fluid pas sage 28 therein arranged to establish a constant communication between said first and second

annular spaces

12,17; and said auxiliary valve body 21 has a fluid passage means 30 extending therethrough from the front end thereof to said second annular space 17 located within said coaxial bore 18 of said main valve body 4. Valve according to claim 3 wherein said fluid passage means of said auxiliary valve body 21 comprises a fluid passage 30 and a spring-biased check valve 32 communicating with said fluid passage which permits pressure fluid to flow in the direction from said generally central fluid inlet opening 27 of said power cylinder 5 to the front end of said auxiliary valve body 21.

5. Valve according to claim 1 wherein said housing has a packing element 8 arranged within said throughpassage 3, so as to cooperate with said valve body 7 to seal off the front end of said coaxial bore 18 when the main valve body 7 occupies its through-passage 3 blocking position.

6. Valve according to claim 2 wherein said housing has a packing element 8 arranged within said throughpassage 3, so as to cooperate with said valve body 7 to seal off the front end of said coaxial bore 18 when the main valve body 7 occupies its through-passage 3 blocking position.

7. Valve according to claim 1 wherein said power cylinder 5 comprises an abutment member 15 which is arranged to enter the rear end of said main valve body coaxial bore 18 to move said auxiliary valve body 21 relative to said main body 6 and block said restricted flow passage 22 therein when said main valve body 6 occupies its rear full flow position.

8. Valve according to claim 7 wherein said coaxial bore 18 of said main valve body 7 has a rear stop element 25 against which said auxiliary valve body 21 abuts when in its rear, restricted flow passage 22 uncovering position.

9. Valve according to claim 2 wherein said power cylinder 5 comprises an abutment member 15 which is arranged to enter the rear end of said main valve body coaxial bore 18 to move auxiliary valve body 21 relative to said main body 6 and block said restricted flow passage 22 therein when said main valve body 6 occupies its rear full flow position.

10. Valve according to claim 9 wherein said coaxial bore 18 of said main valve body 7 has a rear stop element 25 against which said auxiliary valve body 21 abuts when in its rear, restricted flow passage 22 uncovering position.

Claims

1. Pressure fluid valve for controlling the impact power of pneumatic rock drills by selectively establishing a closed, a substantially unobstructed fully open and a restricted flow passage, comprising: a housing having a power cylinder 5 and a throughpassage 3 for pressure fluid; an elongated main valve body 7 movably mounted in said housing and being transversely movable between a rear position in which said through-passage 3 is fully and substantially unobstructedly opened, and a forward position in which said through-passage 3 is blocked; a control piston 6 reciprocably guided within said power cylinder 5 and coupled to said main valve body 7; said main valve body 7 being provided with a transverse, restricted flow passage 22 and a coaxial bore 18 extending axially throughout said main valve body 7; an auxiliary valve body 21 reciprocably guided within said coaxial bore 18 of said main valve body 7 for movement between a position covering said restricted flow passage 22 and a position uncovering said restricted flow passage 22; said control piston 6 having an opening at its rear end portion communicating with the rear end of said auxiliary valve body 21; and a pressure fluid inlet 14 at the rear portion of said power cylinder 5 through which pressure fluid is suppliable onto the rear end of said control piston 6 and the rear end of said auxiliary valve body 21 for moving said main valve body 6 into its through-passage 3 blocking position and said auxiliary valve body 21 into its restricted flow passage 22 covering position.

3. Valve according to claim 1 wherein: said control piston 6 has two axially spaced seal rings 10,11 defining a first annular space 12; said power cylinder 5 has a generally central fluid inlet opening 27 therein so disposed as to remain in constant communication with said annular space 12 between said seal rings 10,11; said auxiliary valve body 21 has two axially spaced seal rings defining a second annular space 17 with said coaxial bore 18 of said main valve body 7; said control piston 6 has a generally radial fluid passage 28 therein arranged to establish a constant communication between said first and second annular spaces 12,17; and said auxiliary valve body 21 has a fluid passage means 30 extending therethrough from the front end thereof to said second annular space 17 located within said coaxial bore 18 of said main valve body 7.

4. Valve according to claim 3 wherein said fluid passage means of said auxiliary valve body 21 comprises a fluid passage 30 and a spring-biased check valve 32 communicating with said fluid passage which permits pressure fluid to flow in the direction from said generally central fluid inlet opening 27 of said power cylinder 5 to the front end of said auxiliary valve body 21.

5. Valve according to claim 1 wherein said housing has a packing element 8 arranged within said through-passage 3, so as to cooperate with said valve body 7 to seal off the front end of said coaxial bore 18 when the main valve body 7 occupies its through-passage 3 blocking position.

6. Valve according to claim 2 wherein said housing has a packing element 8 arranged within said through-passage 3, so as to cooperate with said valve body 7 to seal off the front end of said coaxial bore 18 when the main valve body 7 occupies its through-passage 3 blocking position.