Fluid-flow-regulating Apparatus

Abstract

An apparatus for regulating the flow of an operating fluid to and from a user device. Housing means has a cylinder chamber and a passage for flow of the operating fluid. Valve means is movable in the passage between a normally closed position and an open position in which it permits flow of the operating fluid in pressurized condition to the user device. Control fluid inlet means communicates with the cylinder chamber for admitting a control fluid under pressure into the latter. A valve control piston is operatively associated with the valve means and movable in the cylinder chamber from a rest position via an intermediate position to a control position in which later it displaces the valve means to open position to permit operating fluid to flow away from the user device. First and second channel means are provided in the piston and each communicates with the chamber. The first channel means has a larger and the second channel means has a substantially smaller cross-sectional area and only the first channel means communicates with the inlet means during movement of the piston from its rest position to its intermediate position, while only the second channel means communicates with the inlet means during movement of the piston from its intermediate position to the control position.

Description

BACKGROUND OF THE INVENTION

The present invention relates generally to a fluid-flow-regulating apparatus, and more particularly to an apparatus for regulating the flow of an operating fluid to and from a user device.

Apparatus of this type is known in form of check valves which permit the flow of an operating fluid under pressure to a user device, but which do not permit the return flow of such operating fluid. A separate control piston is provided which is energized by control fluid under pressure when it is desired for the operating fluid to be permitted to flow back away from the user device through the valve. The piston then displaces the valve to open position, thus permitting the operating fluid to flow away from the user device, that is in the direction opposite to that in which it was first flowing under pressure. In known apparatus of this type, however, the movement imparted to the control piston which in turn opens the valve, is rather sudden when control fluid under pressure is admitted into the cylinder chamber in which the piston is reciprocable. Because of such sudden movement undesirably high pressure peaks develop and the control piston impinges so strongly against the housing-- on reaching its end position in which it has opened the valve-- that undesired noises routinely develop.

It is clear, of course, that the development of such noises is frequently objectionable, and that the development of the aforementioned pressure peaks can lead to damage of the apparatus, for instance the valve housing.

SUMMARY OF THE INVENTION

It is, accordingly, an object of the present invention to avoid the aforementioned disadvantages of the prior art.

More particularly it is an object of the present invention to provide an apparatus for regulating the flow of an operating fluid to and from a user device, which is not possessed of these disadvantages.

Still more particularly it is an object of the present invention to provide such an apparatus wherein the development of the aforementioned undesired pressure peaks is avoided and wherein similarly the development of undesired noises is avoided.

In pursuances of the above objects, and others which will become apparent hereinafter, one feature of the invention resides in an apparatus for regulating the flow of an operating fluid to and from a user device, which apparatus comprises housing means having a cylinder chamber and a passage for flow of the operating fluid. Valve means is movable in the passage between a normal closed position and an open position permitting the flow of pressurized operating fluid to the user device. Control fluid inlet means communicates with the cylinder chamber for admitting into the latter a control under pressure. Valve control piston means is operatively associated with the valve means and is movable in the cylinder chamber from a rest position via an intermediate position to a control position in which it displaces the valve means to open position for permitting a flow of operating fluid from the user device. Finally, first and second channel means are provided in the piston means each communicating with the chamber and respectively having larger and substantially smaller cross-sectional areas. Only the first channel means communicates with the inlet means during movement of the piston means from the rest position thereof towards the intermediate position, and only the second channel means of substantially smaller cross-sectional area communicates with the inlet means during movement of the piston means from the intermediate position towards the control position thereof.

The construction according to the present invention is not only simple and therefore relatively inexpensive, but it is highly efficient and reliable in performing its primary intended functions-- namely the control of the flow of an operating fluid to and from a user device-- as well as the purposes which are to be fulfilled according to the present invention, namely the avoidance of undesired and possibly damaging pressure peaks and the avoidance of noise development.

The novel feature which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

The single FIGURE is a longitudinal section through an apparatus according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Discussing now the drawing in detail it is firstly emphasized that the illustrated embodiment is purely exemplary and that modifications and changes will offer themselves readily to those skilled in the art without, however, requiring a departure from the concept and scope of the present invention.

Keeping this in mind it is pointed out that reference numeral 1 identifies one section of a valve housing a second section of which is identified with reference numeral 16. Of course, the sections 1 and 2 could be given different names but inasmuch as they are invariably associated with one another in a sense in which they are fast with one another, the sections 1 and 16 may be considered as two sections of a common valve housing.

The section 1 is provided with a passage 11 for the flow of operating fluid therethrough. The passage 11 has an inlet 12a communicating with the diagrammatically illustrated fluid source of operating fluid, and an outlet 12b communicating with a nonillustrated but diagrammatically shown user device. Interposed in the passage 11 is a sleeve portion 2 which accommodates a substantially cup-shaped valve body 3 of a main valve. A shoulder 4 is provided in the sleeve 2 against which the valve body 3 can abut and for which valve body 3 it constitutes a valve seat.

The bottom wall of the valve body 3 is provided with a central bore 5 penetrated by a projection or pin 6 of a second smaller valve body 7 of a control valve. The edge of the bore 5 is configurated as a valve seat which cooperates with the valve body 7. A shoulder 8 on the valve body 7 is engaged by one end of a spring--here a helical spring--identified with reference numeral 9 whose other end abuts against a cover 10 which encloses the interior of the passage 11 with respect to the ambient surroundings and is connected with the housing section 1 in suitable manner. The spring 9 constitutes the closure or spring or biasing means both for the valve body 7 and for the valve body 3 and it will be readily understood.

The valve body 3 is provided with one or more bores or apertures 24 and the sleeve 2 is provided with one or more bores or apertures 25 which communicate with an annular portion 11a of the passage 11, which annular portion 11a surrounds the sleeve 2.

The wall portion separating the interior of the passage 11 from the cylinder chamber 15 provided in the housing section 16, is provided with a bore or similar apertures 13 which is coaxial with the valve body 3 and through which an actuating portion, here illustrated as a rod or pin-shaped member 14, extends slidably but in sealtight relationship. One end portion of the member 14 is thus located in the passage 11 and the other end portion in the cylinder chamber 15, as illustrated. The sealing means providing a sealtight accommodation of the member 14 in the aperture 13 are illustrated but not separately identified with a reference numeral because they in themselves do not constitute a part of the invention.

A control position 17 is slidably accommodated in the chamber 15 for movement between the illustrated rest position and an operating position in which it is located at the right-hand end of the chamber 15, via an intermediate position. A channel 18 constitutes an inlet channel for the admission of pressurized control fluid into the chamber 15 from the diagrammatically illustrated control fluid source. Interposed between this control fluid source and the channel 18 is a valve 18a which is normally closed but is operated to open when it is desired to operate the device in a sense permitting the return flow of operating fluid for the user device via the valve and passage 11 to the inlet 12a thereof. The channel 18 terminates in and communicates with an annular groove 19 provided in the inner surface or wall bounding the chamber 15, as illustrated. As also illustrated, the piston 17 is provided with at least one but preferably several transverse bores 20 which extend inwardly from its outer circumferential surface. These bores 20 communicate inwardly of this outer circumferential surface with axially extending bores 21 which extend in at least substantial parallelism with the axis of the piston 17 and which terminate at that axial end face 22 of the piston 17 which faces the end of the chamber 15 where the piston 17 is normally located in its rest position, that is the position in which it is illustrated in the drawing. These bores 20 and 21 may also be considered first channels with the bores 20 constituting first channel portions and the bores 21 constituting second channel portions.

There are further provided additional bores or second channels 23 which extend inwardly from the outer circumferential surface of the piston 17, in the manner of the bores 20, and which also communicate with the bores 21. However, as clearly shown in the drawing the bores 23 have a substantially smaller cross-sectional area than the bores 20. They are also located intermediate the bores 20 and the end face 22, that is they are located closer to the end face 22 than are the bores 20.

During regular operation of the illustrated apparatus in which an operating fluid moves from the fluid source through the passage 11 and via the bores 24 and 25 through the outlet 12b of the passage 11 to the nonillustrated user device, the piston 17 will be in the position illustrated in the drawing. If it is desired to reverse the direction of flow of the operating fluid, that is to permit the operating fluid to pass from the user device via the outlet 12b and the bores 25, 24 through the passage 11 to the inlet 12a thereof, then the valve members 3 and 7 must of course be opened. It will be appreciated that these valve members 3 and 7 are normally in closed position under the influence of the biasing spring 9, but during flow of operating fluid under pressure from the inlet 12a to the outlet 12b are displaced to open position by the force of the operating fluid. When the reverse flow of fluid is desired, then of course the flow of incoming pressurized operating fluid does not exist and therefore the spring 9 biases the valve members 3 and 7 to closed position in which they are illustrated. To open these valve members 3 and 7, the valve 18a is opened to thereby permit the inflow of pressurized control fluid from the control fluid source via the channel 18 into the groove 19. As the drawing shows, the left-hand edge 26 bounding the groove 19 is located somewhat to the left of the right-hand edge of the bores 20, meaning that part of the cross section of the bores 20 is exposed to and communicates with the annular groove 19. This part amounts to approximately the cross secton of the bores 20. The pressurized control fluid can thus enter from the groove 19 into the bores 20 and passes from there via the bores 21 to the axial end face 22, creating pressure there between the bottom or end wall of the chamber 15 and the end face 22 with the result that the piston 17 begins slowly to move toward the right-hand side in the drawing. This slow movement continues until the entire cross-sectional areas of the bores 20 communicate with the groove 19, at which time the piston 17 receives a strong impetus towards the right-hand side of the chamber. Such movement continues until the second right-hand edge 27 bounding the groove 19 progressively obstructs the cross section of the bores 20 until the bores 20 are finally completely cut off from communication with the groove 19. As this movement takes place, and at this time the piston 17 has not yet reached its right-hand end position which is the control position, the substantially smaller cross-sectional areas of the bores 23 become progressively exposed to communication with the groove 19, so that--after the bores 20 are cut off from such communication by the edge 27--the pressure medium or pressurized control fluid can flow from the groove 19 towards the end face 22 only in smaller throttled quantities, owing to the smaller cross-sectional areas of the bores 23. This of course results in a concomitant throttling of the speed of movement of the piston 17 towards the right-hand side in the drawing, so that the piston 17 will finally abut gently against the wall separating the chamber 15 from the passage 11. Of course, as the piston 17 moves towards the right it displaces the member 14 concomitantly towards the right, and in turn the member 14 displaces the valve members 3 and 7 against the force of the biasing spring 9 to the right to valve-opening position where they are maintained as long as it is desired for operating fluid to flow from the user device towards the inlet 12a of the passage 11.

By resorting to the construction according to the present invention, undesired and possibly dangerous or at least deleterious pressure peaks after closing of the bores 20 by the edge 27, as well as at the time the piston 17 reaches its control position, are completely avoided. Because the piston 17 now abuts rather gently against the divider wall portion separating the chamber 15 from the passage 11, the undesired noise known from the prior art is also avoided. Of course, the positioning of the groove 19 on the inner circumferential surface 15a bounding the chamber 15, with reference to the bores 20 and 23 can be readily determined in dependence upon the dimensions and the travel involved.

When it is desired to terminate the flow of operating fluid from the user device, the valve 18 is closed. Deprived of the pressure from the control fluid, the piston 17 yields to the restoring force of spring 9 which is exerted upon the valve members 3 and 7 and via the same and the member 14 upon the piston 17. The valve members 3 and 7 return to closed position and the piston 17 is displaced towards the left (in the drawing) to the illustrated position. The control fluid which is displaced from chamber 15 as a result of this movement of piston 17 flows without pressure through the channel 18 to a (nonillustrated) reservoir or receptacle.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a fluid-flow-regulating apparatus, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

Claims

We claim:

1. An apparatus for regulating the flow of an operating fluid to and from a user device, comprising housing means having a cylinder chamber, and a passage for flow of said operating fluid; valve means movable in said passage between a normal closed position and an open position permitting the flow of pressurized operating fluid to said user device; control fluid inlet means communicating with said cylinder chamber for admitting into the latter a control fluid under pressure; valve control piston means operatively associated with said valve means and movable in said cylinder chamber from a rest position via an intermediate position to a control position for permitting a flow of operating fluid from said user device; and first and second channel means provided in said piston means each communicating with said chamber and respectively having larger and substantially smaller cross-sectional areas, only said first channel means communicating with said inlet means during movement of said piston means from said rest position towards said intermediate position, and only said second channel means communicating with said inlet means during movement of said piston means from said intermediate position towards said control position.

2. An apparatus as defined in claim 1; and further comprising biasing means acting upon said valve means and permanently urging the same to said closed position.

3. An apparatus as defined in claim 1, said chamber having a first end and a second end at which said piston means is respectively located when in said rest and control positions, and said piston means having an end face facing towards said first end; and wherein said first channel means comprises at least one channel provided in said piston means and communicating with said end face and with a circumferential surface of said piston means.

4. An apparatus as defined in claim 3, said one channel comprising a first channel portion extending into said piston means inwardly from said circumferential surface, and a second channel portion communicating with said first channel portion inwardly of said circumferential surface and extending axially of said piston means to said end face.

5. An apparatus as defined in claim 4, said second channel means comprising at least one second channel having a substantially smaller cross-sectional area than said first channel portion an extending inwardly from said circumferential surface to and into communication with said second channel portion.

6. An apparatus as defined in claim 5, said second channel and said first channel portion of said channel each having an opening provided in said circumferential surface; and wherein the opening of said second channel is spaced from the opening of said first channel portion axially of said piston means and in direction towards said end face.

7. An apparatus as defined in claim 1, said control fluid inlet means comprising a circumferential groove provided in the circumferential wall bounding the interior of said cylinder chamber and positioned to be fluid-tightly closed by said piston means when the latter is in said rest position thereof, and an inlet channel communicating with said groove and having an outer end adapted to be connected with a source of pressurized control fluid.

8. An apparatus as defined in claim 7; further comprising a source of pressurized control fluid connected with said outer end; and a normally closed valve interposed between said source and said groove.

9. An apparatus as defined in claim 1; said housing means comprising a first housing section provided with said passage, and a second housing section fast with said first housing section and provided with said cylinder chamber.

10. An apparatus as defined in claim 9, one of said housing section having a wall portion located between and separating said passage and said cylinder chamber, and said wall portion being provided with an aperture communicating with both said passage and said chamber; and further comprising an elongated actuating portion slidably but fluid-tightly accommodated in said aperture and having one end portion located in said chamber and an other end portion located in said passage, said one end portion being positioned to be engaged by said piston means upon movement of the same to said control position for concomitant displacement of said actuating portion in direction towards said passage and engagement of said other end portion with said valve means in a sense displacing the latter to said open position.