Title:
VALVE ASSEMBLIES FOR SEQUENTIALLY ACTUATING FLUID-OPERATED PARTS
United States Patent 3590686


Abstract:
Valve assemblies for sequentially actuating parts which are operated by pressure fluid. The assembly includes a housing which accommodates a plurality of control valves for movement, the several control valves being operatively connected with the several fluid-operated parts for actuating the latter. Each control valve is guided by the housing for movement between a first and a second position and is urged by a spring to the first position. Moreover, each control valve has a differential piston portion which responds to the pressure of the fluid for opposing the spring to displace each control valve from its first to its second position. The housing has a common supply of pressure fluid for all of the control valves and a common low pressure return for all of the fluid-operated devices. The assembly operates to connect the pressure fluid sequentially to the several fluid-operated parts while maintaining those of the latter devices which are not connected with pressure fluid with the common return. Each of the movable control valves moves with a sudden, impact-type of movement from its first to its second position and in both positions influences not only the particular fluid-operated part with which it is connected but also the fluid-operated part connected to the next-following control valve.



Inventors:
BOCK RUDOLF
Application Number:
04/827210
Publication Date:
07/06/1971
Filing Date:
05/23/1969
Assignee:
RUDOLF BOCK
Primary Class:
International Classes:
F15B11/20; (IPC1-7): F15B21/00; F01B21/00
Field of Search:
91/36,412,2,35
View Patent Images:
US Patent References:
3367238Valve and method for operating mechanical tuyere puncher and the like1968-02-06Magee et al.
3058310Fluid apparatus1962-10-16Panissidi
2696082Rotary distributing valve control apparatus1954-12-07Fouron et al.
2301028Power transmission1942-11-03Esch
1994974Differential resistance valve1935-03-19Wiedmann
1745707Valve-controlling mechanism1930-02-04Perrett



Primary Examiner:
Geoghegan, Edgar W.
Claims:
What I claim is

1. In a fluid-pressure valve assembly for sequentially placing pressure fluid in communication with a series of fluid-operated means while simultaneously maintaining the plurality of fluid-operated means which are not connected with the pressure fluid at a low discharge pressure, valve housing means, a plurality of movable control valve means supported for movement by said valve housing means for respectively communicating with and controlling the plurality of fluid-operated means which are to be sequentially actuated, said valve housing means having a supply conduit means operatively connected thereto for communicating with a source of pressure fluid and for supplying the fluid to all of said movable control valve means, said valve housing means also having a common return conduit means for all of said fluid-operated means, a plurality of yieldable positioning means respectively connected operatively with said plurality of movable control valve means for urging the latter to a first position, each of said control valve means being movable from said first position in opposition to said yieldable positioning means to a second position, and each of said control valve means having a differential piston portion for responding to the pressure of the fluid to oppose the yieldable means and displace each control valve means from said first to said second position thereof, and each of said control valve means controlling in both of its positions not only the fluid-operated means operatively connected to the control valve means to be actuated thereby but in addition influencing the operation of the next-following fluid-operated means.

2. The combination of claim 1 and wherein said valve housing means provides on both sides of the differential piston portion of each movable control valve means a pair of valve seats with which said movable control valve means coacts, and said differential portion of each control valve means terminating at least at one end in a concave surface portion and having a knife edge surrounding said concave surface portion for fluid-tightly engaging one of said valve seats, said housing being formed at said one valve seat for each control valve means with a passage to the next-following control valve means and with a passage to the next-following fluid-operated means which is to be actuated, so that engagement of said knife edge with said one valve seat controls the flow of pressure fluid through said passage to the next-following control valve means and fluid-operated means which is to be actuated.

3. The combination of claim 2 and wherein each movable control valve means has a throttling pin which extends into and closes an entrance end of said passage from one control valve means to the next control valve means when each control valve means is in said first position thereof, and said throttling pin remaining in said entrance end of said passage during part of the movement of each control valve means from said first to said second position, so that the pressure fluid cannot flow through each passage from one to the next-following control valve means until each control valve means has moved at least part of the way from said first to said second position thereof.

4. The combination of claim 1 and wherein each of said movable control valve means, when it is in its first position, communicates with the next-preceding control valve means and with the fluid operated means to be actuated by the fluid controlled control valve means which is in its first position, and each control valve means when in its first position also providing communication between the next-following fluid-operated means which is to be actuated by the fluid controlled next-following control valve means and the common return conduit means.

5. The combination of claim 1 and wherein each of said movable control valve means provides when it is in its second position communication with the next-preceding movable control valve means and with the next-following control valve means, and each control valve means when in its second position connecting the fluid-operated means with which it coacts to the common return conduit means.

6. The combination of claim 1 and wherein said plurality of control valve means form a series, primary valve means communicating with the first in the series of movable control valve means and with the supply conduit means for controlling the flow of fluid therefrom to the first of the series of movable control valve means, and the last of the series of movable control valve means coacting with said primary valve means for actuating the latter to place said supply conduit means directly in communication with said common return conduit means when the last of the series of movable control valve means has been displaced to its second position.

7. The combination of claim 1 and wherein said plurality of valve means form a series, primary valve means coacting with the supply conduit means for placing the pressure fluid therefrom in communication with the first of the series of movable control valve means, and the last of the series of movable control valve means coacting with said primary valve means to actuate the latter said supply conduit means in communication with the first of the series of movable control valve means when said last in the series of movable control valve means is displaced to its second position.

8. The combination of claim 1 and wherein the plurality of positioning means which determine the pressure to move the several movable control valve means from their first to their second positions respectively exert different forces on the plurality of movable control valve means.

9. The combination of claim 1 and wherein the plurality of positioning means are respectively in the form of coil springs, and adjusting means connected with each coil spring for adjusting the force thereof.

10. The combination of claim 1 and wherein each of said means for positioning each movable control valve means is in the form of a coil spring having a pair of opposed bent ends, each movable control valve means being formed with a bore receiving one of said ends and said housing means being formed with a bore receiving the other of said ends of each coil spring so that the latter acts not only to yieldably urge a movable control valve means to its first position but also to prevent turning of said movable control valve means

11. The combination of claim 1 and wherein a plurality of setting means respectively coact with said plurality of movable control valve means for selectively setting a preselected one or more of said movable control valve means at a location displaced from its first position.

Description:
BACKGROUND OF THE INVENTION

The present invention relates to valve assemblies for sequentially actuating, in an automatic manner, a series of fluid-operated parts, placing a hydraulic or pneumatic pressure conduit in communication with the series of parts while those fluid-operated parts which are not connected to the pressure fluid are simultaneously placed in communication with a discharge or return line of low pressure.

The sequential connection of a plurality of fluid-operated parts with a pressure fluid, such as a hydraulic or pneumatic fluid, has been heretofore carried out by electrically actuated solenoid valves, with the automatic sequential actuation being controlled by way of electrical switches which respond to the pressure of fluid-operated parts or by way of limit switches which are actuated by the fluid operated parts.

Devices of this general construction have the disadvantage of requiring an electrical supply system and of requiring control elements to be situated in the regions where the fluid-operated devices are located, so that the range of use of such fluid-operated parts is relatively limited. There are known hydraulic reversing valves which can be used with at least a pair of fluid-operated parts for reversing the flow of pressure fluid from one to the other of the fluid-operated parts. However, these devices have the disadvantage of requiring the second fluid operated part to which the pressure fluid is directed to operate at least at a pressure as high as the reversing pressure, at which the second part is actuated. As soon as the actuating pressure of this second part drops the first fluid-operated part is again placed in communication with the pressure fluid. Thus, a sequential actuation of several such reversing valves is not a practical possibility because the operating pressure of the last fluid-operated part must be substantially greater than the reversing pressure of the first fluid-operated part. In general, systems which are operated by hydraulic or pneumatic pressure use a common source of fluid under pressure, and this common source is set for a given rated pressure which is required to influence all of the fluid-operated parts in most cases.

SUMMARY OF THE INVENTION

It is accordingly a primary object of the present invention to provide a valve assembly for sequentially actuating fluid-operated parts, with this valve assembly of the invention avoiding all of the above drawbacks.

In particular, it is an object of the invention to provide a construction of this type which can situate all of the controls in a common housing.

Moreover, it is an object of the invention to provide a construction which will enable the individual fluid-operated devices to be sequentially actuated while at the same time having very sharp pressure drops without any danger of reversing the sequence of the series of actuation of the fluid-operated devices. Thus, it is an object of the invention to provide a construction which will reliably prevent the sequential actuation from being reversed.

Also, it is an object of the present invention to provide for a series of sequentially actuated fluid-operated devices, the possibility of actuating the several fluid-operated parts at different pressures which may be preselected.

In accordance with the invention the valve assembly which brings about the sequential actuation of the fluid-operated parts includes a common valve housing means having a common pressure fluid supply and a common return flow. In this housing there are, for the several sequentially actuated fluid-operated parts, a plurality of movable control valve means which are urged to first predetermined positions by springs and which are movable to second positions in opposition to these springs which form a yieldable positioning means. The control valves move in a sudden manner from the first to the second positions and include differential piston portions which respond to the reversing pressure of the fluid. Each control valve influences in both of its positions the fluid-operated part which is connected to each control valve as well as the next-following fluid-operated part. The differential piston portion of each control valve is situated between a pair of valve seats of the housing means and terminates at least at one end in a slightly concave end surface surrounded by a knife edge which fluid-tightly engages one of the valve seats so as to guarantee a proper control of the flow of pressure fluid to a passage which leads to the next-following fluid-operated part.

With the structure of the invention the reversing pressure which brings about sequential actuation from one fluid-operated part to the next acts only on the differential piston portion of each movable control valve. The particular surface which is acted upon by this reversing pressure need only be a small percent of the area of the end surface which is surrounded by the knife-edge rim. Because of the small differential piston area for the reversing pressure, only a relatively weak return spring is required to yieldably position each control valve in its first position. The newly actuated fluid-operated part can have a pressure which, with respect to the reversing pressure, has the same relationship, which is to say can drop with respect thereto as sharply, as the differential piston area which brings about movement in the same direction. This relatively low minimum pressure need not be raised at the next-actuated fluid-operated part.

As a result of the knife-edge configuration of the rim surrounding the end of the differential piston portion it becomes possible to very precisely maintain the important relationship between these control surfaces in connection with the particular variations in the pressure. Until the beginning of a reversing movement, the knife-edge rim which surrounds the concave end surface of a piston fully closes a passage for the pressure fluid and avoids any formation of an undesirable gap in a fully reliable manner. Upon raising of this end surface of the piston from its valve seat, as a result of the reversing pressure which acts on the differential piston area, the pressure fluid flows to the concave end surface of the piston into the hollow space defined thereby. Inasmuch as this hollow space becomes deeper toward the center of the piston, the speed of flow of the pressure fluid diminishes so that at this end of the piston there is immediately a stronger static pressure action which quickly and suddenly displaces the control valve with an impact-type of movement, to its second position.

In accordance with the invention each movable control valve has a throttling pin which in the first position of each control valve, and during part of its movement toward its second position, extends into the entrance end of a passage from one control valve to the next-following fluid-operated part. In this way, upon movement of a control valve to its valve seat there will not be a sudden flow of the pressure fluid into the next-following fluid-operated part so that it is not possible for any suction action to influence the valve and to undesirably detract from the springy type of movement it takes from its first to its second position. On the other hand, this throttling pin guarantees that the fluid under pressure will flow to the next-following control valve only when the moving control valve has closed a second connecting passage. Each control valve forms in its first position, in accordance with the invention, not only a connection between the passage to the next-preceding control valve and the passage to the fluid-operated part which is actuated by the particular control valve, but in addition there is provided through a second connecting passage to the next-following control valve a connection between the next-following fluid-operated part and the common return flow. This latter connection must first be interrupted by the control valve before the passage which directs the fluid under pressure to the next-following control valve is opened.

Each control valve forms, in its second position, a connection between the passage to the immediately-preceding control valve and the passage to the next-following control valve, and also each control valve forms in its second position a connection between the fluid-operated part actuated thereby and the return.

The valve assembly of the invention is preferably provided with a primary operating valve which controls the flow of pressure fluid to the first of the series of movable control valves and which, for example, can be actuated at the will of the operator. In addition this primary valve can be automatically positioned by the last of the series of control valves so as to place the supply line for the pressure fluid in communication with the common return or, instead, with the first of the series of control valves, so that with this latter type of construction the series of fluid-operated parts are repeatedly operated in sequence one after the other.

The several positioning means which yieldably position the several control valves in their first positions take the form of a plurality of return springs which can respectively have different return forces. The structure can be made in such a way that the prestress of several return springs can be adjusted. According to a preferred form of the invention the several control valves are urged back toward their initial positions by coil springs the ends of which are bent and received, on the one hand, in openings in the control valves and, on the other hand, in openings in the valve housing, so that not only do such springs act to return the control valves to their first positions but in addition they prevent turning of the control valves so that no particular guides, such as keys and key ways, or the like are required to prevent rotary movement of the control valves.

BRIEF DESCRIPTION OF DRAWINGS

The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a schematic sectional elevation of a valve assembly of the invention taken in a central vertical plane which includes the central axis of the assembly, the section of FIG. 1 being taken along line I-I of FIG. 2 in the direction of the arrows;

FIG. 2 is a plan view of the assembly of the invention showing the housing which is common to the several valves;

FIG. 3 is a fragmentary sectional elevation of the upper part of the common valve housing, taken along III-III of FIG. 2 in the direction of the arrows;

FIG. 4 is also a fragmentary sectional elevation of the upper part of the valve housing with the structure therein, FIG. 4 being taken along IV-IV of FIG. 2 in the direction of the arrows;

FIG. 5 is a sectional plan view taken along V-V of FIG. 1 in the direction of the arrows;

FIG. 6 schematically illustrates six fluid-operated parts in the form of the opposed end portions of three pressure cylinders respectively accommodating double-acting fluid-operated pistons therein;

FIG. 7 is a fragmentary sectional elevation taken along line VII-VII of FIG. 2 in the direction of the arrows and showing the parts on a scale which is enlarged as compared to FIGS. 1--5;

FIG. 8 is a fragmentary sectional plan taken along line VIII-VIII of FIG. 7 in the direction of the arrows;

FIG. 9 is a fragmentary sectional plan taken along line IX-IX of FIG. 7 in the direction of the arrows; and

FIG. 10 is a sectional elevation taken along the same plane as that of FIG. 7 but showing another embodiment of the structure of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, the assembly of the invention which is illustrated therein for sequentially actuating fluid-operated parts includes a valve housing means 10 which is common to the several movable control valve means referred to below and which is composed of a plurality of housing parts including the upper head part 101, the central housing part 102, and the lower chamber-defining part 103 connected at its bottom end to the bottom wall component 104 of the housing means 10. These four parts of the housing means 10 are maintained in their assembled condition by a plurality of connecting screws 11, of which only one is illustrated in FIG. 1.

As the central section of FIG. 1 shows, the device has, in a central cylindrical bore 12 of the housing means 10, a primary valve 13 having an upper portion 131 which is slidably guided through a suitable bore formed in the upper part 105 which is mounted on the housing, this part 131 extending upwardly beyond the guide component 105 to the exterior so as to be freely accessible. This primary valve 13 has an intermediate portion 132 of reduced diameter and, at its inner or bottom end, it has a control piston portion 133 the significance of which is described below.

Along the periphery of the cylindrical common housing means 10, the upper head part 101 thereof as well as the intermediate central part 102 are formed with six cylinder chambers 14--19 which have parallel axes and which are uniformly distributed about the central axis of the housing which coincides with the axis of the primary valve 13. This arrangement is apparent from FIGS. 2 and 5. In each of the several cylindrical chambers 14--19 there is a control valve, and thus the several axially movable control valve means 20--25 are respectively situated within the several cylinder chambers 14--19 of the common housing means. All of these control valve means 20--25 are of the same construction. In the drawing only the first three control valve means 20--22 of the series of six control valve means, as well as the last control valve means 25 of the series, are illustrated.

Each control valve means has an intermediate portion guided for movement in the intermediate housing part 102 and has an upper differential piston portion 26 situated in the upper housing part 101 in the part of the cylinder chamber which is formed therein. These differential piston portions 26 of the several control valves are described in greater detail below.

The several control valve means 20--25 are, as shown in FIG. 1, movable in opposition to the force of a positioning means in the form of return springs 27 which urge the several control valves 20--25 to their first, upper positions, as viewed in FIG. 1. These positioning springs 27 are in the form of coil springs having bent ends 271 and 272. The upper bent ends 271 are respectively received in bores of the several movable control valve means 20--25 while the lower bent ends 272 of the return springs 27 are respectively received in bores formed in the bottom wall 104 of the housing means. As a result of this construction the several return springs 27 act to prevent turning of the several control valves 20--25 about their parallel axes, so that no special longitudinal guides need be provided for the several control valves.

The several return springs 27 are situated in the hollow chamber 28 defined by the lower housing part 103, this chamber 28 forming an oil collection chamber which communicates through a central opening 29 in the bottom wall 104 with the exterior of the latter. All of the return flow passages communicate with the oil collecting chamber 28, including a primary common return flow passage 30 which is controlled by the primary valve 13. The housing means 10 can be fixed at its bottom wall 104 directly on an oil container so that the central opening 29 in the bottom plate 104 forms a common return flow conduit for all of the fluid-operated parts which are connected to the assembly of the invention.

Inasmuch as the structure concerns a sequential actuation of fluid-operated devices brought about by the valve assembly where several fluid-operated parts are connected to the assembly so as to be actuated one after the other in a predetermined sequence, the first of the series of cylinder chambers 14 for the first of the series of movable control valves 20 is connected by way of a connecting passage 31 with the second cylinder chamber 15. This latter cylinder chamber is in turn connected by way of a passage 32 in the housing means with the next-following cylinder chamber 16. This arrangement is illustrated in FIG. 2. Thus, in the same way the remaining cylinder chambers 16--19 are interconnected one with respect to the next through the connecting passages 33--35 respectively formed in the housing means 10. All of these connecting passages 31--35 are illustrated in FIG. 2. The last cylinder chamber 19 is connected by way of a connecting passage 36 formed in the housing means with the central bore 12 in which the primary valve 13 moves. This bore 12 is in turn connected by way of a passage 37 with the first of the series of cylinder chambers 14. The connection of the assembly of the invention and all of the fluid-operated parts connected therewith to a source of fluid under pressure, such as a hydraulic pump, takes place through a common supply conduit means 38 in the form of a passage formed in the housing means. This common supply conduit means 38 for the pressure fluid also leads to and communicates with the central cylindrical bore 12 for the primary valve 13.

The several fluid-operated parts, which are respectively connected to the several control valve means 20--25, to be actuated by the fluid controlling thereof, are connected to the central housing part 102 at the elevation of section line V-V of FIG. 1, and these connections are illustrated in FIG. 5. All of the fluid-operated parts may have the construction schematically shown in FIG. 6, according to which they are made up of three cylinders A, B, C, each of which has a pair of opposed ends forming a pair of chambers, these opposed chambers receiving fluid under pressure for actuating the double-acting pistons which are slidable in the several cylinders. Thus, the chambers V1 and V2 on FIG. 6 form the pair of opposed chambers of the cylinder A on both sides of the piston therein, while the pair of structure-designated V3, V4 and the structure-designated V5, V6 form chambers in the cylinders B and C on opposite sides of the pistons therein as is apparent from FIG. 6. The chamber V1 is connected by way of a connecting passage 39 of the housing means with the cylinder chamber 14 of the valve housing means 10. The chambers V2 --V6 are respectively connected through the connecting passages 40--44 with the several remaining cylinder chambers 15--19.

As is apparent from FIG. 5, the individual cylinder chambers of the housing means 10 are interconnected with each other not only by way of the several connecting passages 31--35 but also by way of additional connecting passages 45--49. The latter connecting passages 45--49 are respectively in alignment with the connecting passages which connect the cylinder chambers to the fluid-operated parts. Thus, the connecting passage 45 between the cylinder chambers 14 and 15 is alignment with the connecting passage 40 which connects the chamber 15 to the chamber V2. The connection 46 between the cylindrical valve chambers 15 and 16 is in axial alignment with the connecting passage 41 providing the connection between the valve bore 16 and the chamber V3, and so on until finally the connecting passage 49 between the valve chambers 18 and 19 is in axial alignment with the connecting passage 44 which connects the valve bore 19 with the chamber V6. The connection between the pair of coaxial passages of each valve bore is brought about by way of the several control valves 20--25 which move in the several valve bores, as is described in detail below in connection with FIGS. 7--9.

Referring to FIG. 7, the several movable control valve means 20--25 are each provided at their intermediate portions with an upper transverse bore 50 and a lower transverse bore 51, these transverse bores being interconnected by a central axial bore 53. The movable control valve means 20--25 furthermore are provided between their upper differential piston portions 26 and their central guiding parts with portions of reduced diameter in which the transverse bores 50 are formed. At the central portions of the control valves, the latter are provided with an exterior groove 54 (FIG. 8) this exterior groove 54 extending around the axis of each control valve through approximately three-fourths of its circumference. Moreover, each control valve 20--25 is provided at its lower portion with a pair of diametrically opposed longitudinal grooves 55 and 56 (FIG. 9) both of which communicate with and form passages leading to the oil collection chamber 28.

The differential piston portions 26 which are situated in the upper parts of the cylinder chambers 14--19 have a special construction which forms an important part of the invention. As is best shown in FIG. 7, each differential piston portion is relatively small as compared to the upper piston end 58. The differential piston portion 26 is formed by the peripheral part 57 which extends radially beyond the end 58 to only a small extent and which is located with peripheral clearance within the upper part of the particular valve bore.

The upper piston end 58 has a concave configuration and terminates in and is surrounded by a sharp knife edge 59 which has a fluidtight engagement with an upper valve seat 60 formed by the housing means for each control valve when it is in its upper or first position, as shown for the right valve 22 in FIG. 7. Also, the lower end surface 61 of the differential piston portion 26 terminates in a knife-edge periphery and engages in the second, lower position of each control valve, shown for the valve 21 in FIG. 7, the valve seat surface formed by the top surface of the central housing part 102, so that each differential piston portion 26 will have a fluidtight engagement at its knife edge 61 with the upwardly directed valve seats 62. In this way in the second, lower position of each control valve leakage losses are avoided. Such leakage losses could be added to each other to accumulate undesirably at the individual control valves.

Each of the control valve means is provided at its upper piston end 58 with a throttling pin 63 which is coaxial with the particular valve and which, in the first position of each control valve, extends into and closes the passage to the next control valve. Thus, the control valve means 22 is shown in FIG. 7 with its upper throttling pin portion 63 closing the passage 33 to the next-following control valve 23. When the control valve means 21 was in its upper position, the throttling pin 63 thereof closed the passage 32 leading from the control valve 21 to the control valve 22 in the manner shown in FIG. 7. In this way the several coaxial throttling pin portions 63 at the top ends of the several control valves 20--25 serve to close the passage of the next control valve in the upper, first positions of the valves to which they are urged by the several springs.

The above-described structure operates as follows:

In the rest position of the assembly of the invention, all of the several control valve means 20--25 are situated in their upper, first positions, as shown, for example, in FIG. 1. This is the position which the parts assume when the system is not under pressure or when the several fluid-operated parts are connected to the low-pressure return,

so that the return springs 27 serve to position the several control valves in their first positions.

The primary valve 13, in the rest position of the assembly, is in the upper position illustrated in FIG. 3. In this rest position the lower piston part 133 of the primary valve 13 blocks the passage 37 which provides communication between the bore 12 and the first of the series of valves namely control valve means 20 which is in the valve bore 14. Thus, the pressure fluid which is supplied through the supply conduit means 38 flows into the bore 12 around the intermediate portion 132 of valve 13, which is of reduced diameter as shown in FIG. 3, and this pressure fluid flows freely to the top end of the low-pressure return conduit 30 to flow down the latter into the collecting chamber 28 of the housing means 10. In this way the fluid supplied at this time through the supply conduit 38 flows through the return conduit 30 directly to the chamber 28 and from the latter through the return conduit 29 into the container for the fluid (schematically illustrated in FIG. 1 and designated as a reservoir) such as a suitable reservoir from which the oil is pumped to the supply conduit 38.

In order to initiate the sequential actuation of the several fluid-operated parts the operator will simply depress the primary valve 13 so that it will now have the position shown in FIG. 4. In this way the direct connection between the supply conduit 38 and the return flow conduit 30 is interrupted, inasmuch as the upper portion 131 will at its lower end block the communication between the top end of the bore 30 and the interior of the bore 12, as is apparent from FIG. 4. However, the downward movement of the piston portion 133 uncovers the passage 37 which leads to the bore 14, so that now the pressure fluid can flow through the bore 37 directly into the bore 14 where the first control valve 20 of the series of control valves is located. When the control valve 20 is in its upper, first position, corresponding to the position of the valve 22 shown in FIG. 7, the fluid which enters through the passage 37 can flow into the transverse bore 50 of the control valve 20. From the transverse bore 50 the fluid can flow down the axial bore 53 into the lower transverse bore 51 which at this time is at the elevation of and coaxial with the connecting passage 39 which leads to the chamber V1, so that, as is indicated by the double-headed arrow in FIG. 5, the fluid can flow through the passage 39 into the upper chamber V1 of the cylinder A schematically shown in FIG. 6.

When the pressure fluid is received in this upper chamber V1 piston in the cylinder A will be displaced downwardly, as viewed in FIG. 6. This piston will continue to move down until it reaches a bottom stop which limits the downward movement, and as soon as the piston reaches its lower end position in the cylinder A, further downward movement of this piston can no longer take place so that the pressure in the passages where the pressure fluid is located increases. As a result the pressure within the chamber 14 will increase. The increasing pressure of the fluid within the bore 14 will cause the fluid to act on the differential piston area 57 of the differential piston portion 26 of the control valve 20. As soon as this pressure acting on the differential piston portion reaches a value slightly greater than the force of the return spring 27, this valve 20 will start to move downwardly, with the result that its upper sharp knife edge 59 is displaced downwardly away from the valve seat 60. Now the oil under pressure can flow through the gap between the seat 60 and the knife edge 59 so that the pressure in the bore 14 acts, and becomes effective, over the entire end 58 of the piston portion of the valve. In this way a springy sudden downward impact-type of movement is imparted to the control valve 20 so that it jumps down to its second position where the lower piston end surface 61 of the differential valve portion 26 engages the valve seat 62 while the upper part of the bore 14 becomes closed off from the part of the bore 14 which is situated in the central housing part 102. In this way oil leakage loss is maintained as small as possible.

During the initial part of the downward movement of the control valve 20 toward its lower, second position, the upper throttling pin 63 of the control valve still remains in the entrance end of the passage 31 which provides communication between the valve bores 14 and 15. This passage 31 has the same configuration as the passage 32 shown in FIG. 7, except that the passage 31 provides communication between the bores 14 and 15 while the passage 32 of FIG. 7 provides communication between the bores 15 and 16. Thus, a rapid flow of the fluid past the end surface 58 during the initial movement thereof away from the valve seat 60 is prevented so that a suction action on the control valve 20 opposing its downward movement, so as to act undesirably on the springy jump-type of sudden movement to the second position, is avoided. Moreover, this throttling pin portion 63 assures a downward movement of the control valve 20 until the passage 31 is completely opened to such an extent that the transverse bore 51, when the throttling pin 63 leaves the entrance end of the passage 31, is no longer in line with the connecting passage 39 leading to the chamber V1, and thus the initial communication between the next-following control valve 21 at the connecting passage 45 is interrupted and the low-pressure passage 56 will now no longer communicate with the connecting passage 45.

As is apparent from FIG. 7, the connecting passage 45, which is analogous to the passage 46 shown in FIG. 7, and the low-pressure passage 56 of the valve 20, which is analogous to the valve 21, were in communication with each other in the upper position of the valve 20, so that during downward movement of the piston in the cylinder A the second chamber V2 formed by the lower part of the cylinder A is in communication with the low-pressure passage 56 leading to the collection chamber 28 during the downward movement of the piston in the cylinder A while the upper part V1 is supplied with fluid under pressure. Thus, before the fluid under pressure which enters through the inlet passage 37 into the bore 14 flows through the passage 31 to the cylinder bore 15, while the control valve 20 dwells at its lower, second position, so that the fluid can now flow through the transverse bore 50 of the control valve 21 and then down the central bore 53 thereof to the transverse bore 51 to reach through the connection passage 40 the chamber V2, the previous communication between the connecting passage 45 and the low-pressure passage 56 of the control valve 20 is interrupted. At the same time that the control valve 20 reaches its lower second position, the chamber V1 is placed in communication with the low return pressure by way of the connection 39, the groove 54, and the axial groove 55, so that now the fluid can flow freely from the chamber V1 back into the oil collecting chamber 28, during the return movement of the piston in the cylinder A, shown in FIG. 6.

The oil under pressure which now flows into the chamber V2 thus moves the piston in the hydraulic cylinder A upwardly until it engages a stop which limits the upward movement of the piston. When this latter stop is reached, the oil under pressure has its pressure increased during the continued operation of the fluid pressure pump into the pressure side of the system of passages, and thus the pressure of the oil in the bore 15 will rise. The rising pressure acts on the differential piston surface portion 57 of the control valve 21, and when this pressure exceeds that of the return spring 27 which acts on the valve 21, and the force of this latter return spring 27 can be different from the force of the springs acting on the other of the series of valves 20 and 22--25, the sudden downward reversal in the position of the control valve 21 will take place as already described above in connection with the valve 20, so that the valve 21 will now reach the position illustrated in FIG. 7. As a result the connecting passage 32 which leads from the bore 15 to the bore 16 is opened when the throttling pin 63 of valve 21 moves below the entrance end of the passage 32. Now the fluid under pressure can flow through the common supply conduit 38, through the passage 37 leading to the first bore 14, through the passage 31 of the latter into the bore 15, and then through the bore 32 into the third bore 16 from where the fluid can flow through the connecting passage 41 into the chamber V3.

These same operations will now be repeated until the last control valve 25 in the cylinder bore 19 has reached its lower second position. The valve 25 is shown in FIG. 1 in its initial upper position. When it has been displaced downwardly to its lower, second position the pressure fluid which enters the common housing means 10 through the supply conduit 38 will flow through the upper portions of all of the series of cylinder bores 14--19 so as to reach the passage 36 which is shown in FIG. 1. In this way the pressure fluid will flow from the passage 36 to the underside of the lower piston portion 133 of the primary valve 13. As a result the fluid under pressure acts on the primary valve 13 to raise the latter to the initial position, as shown in FIG. 3. In this position the upper part 131 has been displaced upwardly so that now the supply conduit 38 can communicate directly with the return flow conduit 30 while the lower piston portion 133 of the primary valve 13 blocks the passage 37 leading to the first cylinder bore 14. In this way sequential operation of the several pistons in chambers V1 --V6 is terminated and further supply of fluid thereto will not take place until the primary valve 13 is again actuated.

Upon return of the primary valve 13 to its initial position, the several springs 27 return all the valves 20--25 to their upper initial positions. If desired a spring may act on the valve 13 to be opposed when the last valve 25 moves down to its bottom position so that the liquid under pressure will now only act on the valve 13 to bring about a repetition of the sequential valve operation. With such a construction the device will operate continuously, automatically repeating each operating cycle.

As is apparent from the above description, each control valve 20--25 in its upper first position provides a communication between the connecting passage to the previous control valve and the connecting passage to the fluid-operated part which is controlled by the particular control valve, and at the same time through a second connecting passage, communication is provided through the next-following control valve between the next-following fluid-operated part and the return flow conduit. This alternating action between a pair of adjoining control valves is, together with the particular configuration of the control valves and the arrangement of the primary valve characteristic of the present invention. The alternating reversing action between the individual control valves is also provided in the second, lower position of each control valve where the control valve provides a connection between the passage leading to the immediately preceding control valve and the passage leading to the immediately following control valve as well as providing a connection between the connecting passage to the particular fluid-operated part which is controlled by the particular control valve and the return flow line and finally with the common return conduit of the valve assembly.

In the event that the valve assembly of the invention for sequentially actuating the fluid-operated parts is to provide an operation where only individual fluid-operated parts are to be actuated or only part of the series of fluid-operated parts are to be actuated, then it is possible to provide the valve assembly of the invention with additional devices, as shown in FIG. 10, capable of selectively placing predetermined control valves at locations displaced from their upper first positions, so that these thus-selectively displaced control valves will immediately be displaced to their lower second positions as soon as the pressure fluid reaches the particular valve bore in which the preselected control valves are located, with the result that the particular fluid-operated part connected to such preliminarily displaced control valves will not be actuated.

Thus, referring to the particular example of this phase of the invention which is illustrated in FIG. 10, it will be seen that the structure of FIG. 10 corresponds to that of FIG. 7 except that with the embodiment of FIG. 10 the selectively operated controls are provided. With this embodiment, in every raised upper housing head part 101' of the common housing means 10 there is in the region of each of the control valves 20--25 a setting means 70 which acts on the particular control valve. This setting means includes a threaded sleeve 71 fluid-tightly carried by the housing part 101' and extending to the exterior of the housing. This sleeve 71 serves to fluid-tightly guide an adjusting shaft 73 provided at its outer end with an operating handle 72. The shaft 73 carries at its inner end an eccentric control member 74 which has the upper rest position 74' shown at the right part of FIG. 10 and the lower operating position shown at the left part of FIG. 10. Thus by turning the handle 72 it is possible for the eccentric control part 74 to be turned from the upper position shown at the right of FIG. 10, where it will have no influence on the operation, to the lower position shown at the left part of FIG. 10 where it will engage the top end of the throttling pin 63. By pressing downwardly on the throttling pin 63 the knife edge 59 surrounding the end surface 58 is displaced downwardly from the valve seat 60, so that when the selected ones of the setting means 70 have been actuated the fluid under pressure which flows into a valve bore, such as that shown at the left of FIG. 10, immediately displaces the control valve down to its second position so as to free the communication to the next-following valve bore and the control valve therein. Thus, by way of the several setting means 70 it is possible to selectively take fluid-operated parts, individually or together with others, out of the sequence of operations. The setting means 70 of course can have many different types of constructions and can, for example, be actuated pneumatically, hydraulically, electrically, and in particular electromagnetically.

With the embodiments of the invention described above, the return springs 27 which form the positioning means for positioning the several control valve means in their upper, first positions, are anchored at their bottom ends 272 in the bottom wall 104 of the housing means 10. These lower ends of the springs 27 can, however, be anchored in a special bearing plate which by way of suitable adjusting screws can be vertically adjusted so that in this way the prestressing of the return springs can be adjusted initially or after the parts have been set up and even when they are operating. The constructive form of a valve assembly according to the invention can be changed in many ways. In the illustrated example the individual control valves are arranged along a circle in a cylindrical housing so that a particularly compact form of the valve assembly is achieved, and, in particular, oil leakage passages are not required. However, the control valves can be situated in a common valve housing beside each other along a straight line. Also, each of the movable control valves can be situated in its own individual housing with these housings interconnected by exterior conduits, or these individual housings can take a modular form enabling them to be placed one next to the other in series to achieve, also with such construction, the results of the invention.

Although the invention is illustrated and described with reference to a plurality of preferred embodiments thereof, it is to be expressly understood that it is in no way limited to the disclosure of such a plurality of preferred embodiments, but is capable of numerous modifications within the scope of the appended claims.