US3282552A - Hydraulic valve and control means therefor - Google Patents

Description

Nov. 1, 1966 J, J, SOMMESE, SR 3,282,552

HYDRAULIC VALVE AND CONTROL MEANS THEREFOR Filed Aug. 28, 1965 /8 d6 I NVE NTOR.

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/af/QU/.o ,SY/NK) ATTORNEYS United States Patent O 3,282,552 HYDRAULIC VALVE AND CONTROL MEANS THEREFOR Julian J. Sommese, Sr., 127-15 160th St., Jamaica, N.Y. Filed Aug. 28, 1963, Ser. No. 305,074 5 Claims. (Cl. 251-26) This invention relates generally to hydraulic valves and more particularly to hydraulic valves for controlling the operation of hydarulic elevators and the like.

In hydraulic elevator systems, the position of an elevator cab is varied by pumping hydraulic iluid into or draining hydraluic fluid out of a hydraulic ram which supports the elevator cab. The iluid input and output of the hydraulic ram are controlled by a hydraulic valve, which in turn is controlled by manual or automatic valve control means. Since the speed of the elevator ca-b depends on the rate of uid ow at the input or output of the hydraulic ram, the hydraulic valve must be capable of continuous adjustment for differing rates of flow. In addition, it must be capable of being securely locked at any given flow rate, and it must be quick acting in the sense that its flow rate can be quickly and smoothly changed from a relatively high rate to a relatively low rate or vice versa. Furthermore, it should be adapted to be controlled by simple and reliable valve control means, and the control means should be easily adjustable to adapt the valve and the control means to different elevator installations.

Many hydraulic valves and valve control means have been devised in the past to control hydraulic elevators and the like, as exemplified by the valve and valve control means disclosed in U.S. Patent 2,913,070, which was issued on November 17, 1959, to M. N. Nyberg for an Automatic Elevator Control. These prior art valves Were `adequate in t-he iiow rate. In addition, they were diicult to control for slow, continuous variations inthe ilow rate, such as requiredwhen the elevator cab is accelerated from a stop to full speed or decelerated from full speed to a stop. Improved control means have been devised to smooth the operation of these prior art hydraulic valves, as disclosed in copending patent application Serial Number 136,276, which was 'led on September 6, 1961, by James F. MacNair et al. for a Hydraulic Elevator Control, but although these improved control means were very helpful, they did not fully remedy the lack of smoothness for small variations in the iiow rate or slow, continuous variations in the flow rate.

Accordingly, one object of this invention is to provide a hydraulic valve which is capable of continuous adjustments for differing rates of flow.

Another object of this invention is to provide a hydraulic valve which is capable of being securely locked at any given flow rate and which is capable of being quickly and smoothly changed from one flow rate to another.

A further object of this invention is to provide a hydraulic valve which is easly to adjust for small variations in the flow rate thereof.

An additional object of this invention is to provide a simple and reliable control means for a hydraulic valve of the above described type.

Another object of this invention is to provide a control means which is easily adjustable to provide differing rates of change in the ow rate of a hydraluic valve controlled thereby.

Another object of this invention is to provide a control means which is capable of continuously and smoothly varying the ow rate in a hydraulic valve controlled thereby.

Another object of this invention is to provide a control means which is capable of producing small variations in the iiow rate of a hydraulic valve controlled thereby.

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Another object of this invention is to provide a control means which is capable of securely locking a hydraulic valve controlled thereby at any given flow rate and which is capable of .quickly and smoothly changing the flow rate to a diiierent level.

Another object of this invention is to provide a control means of the above described type which is easy to adjust to meet the requirements of different applications thereof.

Another lobject of this invention is to provide a hydraulic valve and hydraulic control means which is simple, reliable, and relatively inexpensive.

Other objects and advantages of the invention will become apparent to those skilled in the art from the following description of one specific embodiment thereof, as illustri-rated in the attached drawing, which shows one speciiic hydraulic valve and valve control means of this invention.

Referring to the ligure, one embodiment of this invention comprises a main hydraulic valve, which is generally indicated by the numeral 10, and a valve control means which includes solenoid valves #l #3, choke valves #1 #3, and a solenoid valve control circuit 12. Main hydraluic valve 10 is similar in construction to the prior art solenoid operated valves, but it differs importantly in that it contains no needle valve or needle valve orilice. The elimination of these parts adapt the valve for continuous variation of fluid flow rather than off-on operation and also allows the fluid inlet and outlet ports to be used interchangably. Valve 10 comprises a body member 14, a piston assembly generally designated by the numeral 16 sildably mounted within body member @14, a fluid inlet port 18, and a uid outlet port 20. Piston assembly 16 is adapted to vary the fluid ilow rate between the inlet and outlet ports in .accordance with its position. In the position shown in the figure, the ow is completely shut off. As piston assembly 16 rises, however, fluid flow will begin and its rate will increase as the piston assembly rises.

Piston assembly 16 contains two leather packings which act as -fluid seals to `divide the interior of body member 14 into an upper fluid chamber 22 and a lower fluid chamber 24. Leather packing 26 seals off upper chamber 22, and leather packing 28 seals off lower chamber 24. A neoprene valve seat 30. seals off the fluid outlet port 20 when the valve is in its closed position. The leather packings an-d neoprene valve seat are securely fastened to 'the valve stem 32 by being sandwiched between the other members of the piston assembly, which include a serrated fluid shield 34 that extends into outlet port 20, a piston member 36, which is recessed to receive valve seat 30, a packing spacer 38, which separates leather packings 26 and 28, and a packing follower 40, which holds leather packing 26 in place. rIhe top of valve stem 32 is enlarged to hold packing follower 40 in place, and the bottom of valve stern 32 is threaded to receive a nut 42 which holds the entire piston assembly together.

It should be noted that packing spacer 38 has a larger diameter at its top than it does at its bottom. This differential of diameter is provided so that the piston assembly will be driven to its closed position when the pressure in upper chamber 22 is equal to the pressure in lower ychamber 24. This follows from the well known principle that the force exerted by a fluid under pressure is equal to the pressure multiplied by the area against which the pressure is exerted. The open space between packing spacer 3S and the wall of the valve body 14 is drained by means of a vent opening 44 which is drilled through the valve body. This prevents any locking of the piston due to trappage of air or hydraulic fluid in the open space. It should also be noted that serrated uid shield 34 provides a smoothly variable increase in the fluid flow rate when it is withdrawn from outlet port 20 f #1 energized.

3 and a smoothly variable decrease in the fluid liow lrate when it is inserted back into outlet port 20. This smooth increase or decrease depends, however, on the smoothness rwith which the position of the piston is varied. Valves of the above described type have been known in the past, but they have-never realized the full potential of their inherent smoothness due to shortcomings in the prior art means for varying the position of the piston.

In accordance with this invention, the position of piston assembly 16 is -controlled by a novel valve control means for pumping fluid into or draining fluid out of .upper chamber 22 of valve 10.` The particular valve control means shown in the ligures contains three solenoid operated valves #1 #3, three choke valves #1 #3, and a solenoid valve control circuit 12 which receives input signals signifying a desired condition in the main valve and which operates the solenoid valves in such a way as to produce the desired condition. In this partic- .ular embodiment four input signals are applied to solenoid valve control circuit 12, (1) a signal signifying the full open condition of main valve 10, (2) a signal signifying the full closed position of main valve 10, (3) a signal signifying an increase in the fluid tlow rate through main valve 10, and (4) a signal signifying a decrease in the fluid llow rate through main valve 10. The operation of .the control means can be best explained by tracing the ,l sequence of events that occur in response to these signals.

In the absence of any signal input to the solenoid valve '.control, iluid entering pipe 46 from the uid source is ,applied directly to lower chamber 24 of main valve 10 and also to upper chamber 22 via choke valve #1 and normally open solenoid valve #1. This produces equal V,pressure in upper chamber 22 and lower chamber 24,

which forces piston assembly 16 downward due to the unequal areas of the top and bottom of the piston, as explained previously, thereby fully closing main valve 10. When an on control signal is applied to circuit 12, normally open solenoid valve #1 and normally closed solenoid valve #2 are energized. This couples upper uid chamber 22 to the fluid sink via choke valve #2 and solenoid valve #2 and allows the pressure in lower chamber 24 to drive piston assembly 16 to the Vfull limit of its upward travel, which is defined by an adjustable stop screw 48l in the top of valve body memyber 14. The iluid in upper chamber 22, of course, is

driven into the fluid sink as the piston assembly 16 rises. An off signal applied to circuit 12 de-energizes solenoid valves #1 and #2, thereby returning main valve 10 to its full closed position. It should be noted that the control circuit is fail-safe in the sense that the main valve 10 will shut itself off in the event of a power failure. When the main valve is used to drive a hydraulic elevator, this means that the elevator will automatically stop in the event of a power failure instead of running wild.

In response to a decrease input signal, control circuit 'y 12 energizes normally open solenoid valve #1 and nor- `mally closed solenoid valve #3, which applies fluid to vupper chamber 22 and securely locks' the piston assembly in place. In response to an increase input signal, normally closed solenoid valve #2 is energized while normally open solenoid valve #1 remains energized This allows tluid to drain from upper chamber 22 at a rate controlled by the setting of choke valve #2. When the ow rate of main valve 10 reaches the desired level, the piston assembly 16 is securely locked in place by deenergizing solenoid valve #2 and holding solenoid valve It will be noted that solenoid valve #1 is energized by either the increase or the decrease signal and that it remains energized after these signals have terminated. This is done by means of an electrical latch back circuit in control circuit 12, as will be readily understood by those skilled in the art. After the latch back circuit has been energized, solenoid valve #1 will remain closed until the latch back circuit is broken by either a power failure or the receipt of an off input signal.

The switching speed, i.e. the rate of change in the flow rate of main valve 10 during the foregoing operations, can be conveniently adjusted to meet the requirements of dilfering applications by means of choke valves #1, #2, and #3. The setting of choke valve #1 controls the switching speed when the main valve 10 is moved to the full off position by an olf input signal or by a power failure. The setting of choke valve #3 controls the switching speed when the llow rate through the main valve 10 is decreased in response to a decrease input signal, and the setting of choke valve #2 controls the switching speed when the llow rate through the main valve 10 is increased in response to an increase input signal or when it is moved to the full on position in response to an on input signal.

The component parts of the above described control means can be any suitable prior art valves, pipes, and couplings which are suited to the particular application of the invention, the type of hydraulic fluid used, and the pressures involved. The solenoid valve control circuit 12 can be any suitable prior art switching circuit which is adapted to receive the input signals used ina particular application of the invention and to switch the solenoid valves in accordance with the above described operating logic. For example, a relay logic circuit might be used, or a solid state logic circuit, or, in the case where the input signals are mechanical variables rather than electrical variables, a mechanical switch might be used.

The above disclosed embodiment of the invention can be applied to hydraulic elevator control systems such as described in the above noted U.S. Patent No. 2,913,070 by simply coupling the main valve of the invention in parallel with the main valve used to control the lluid input and output of the hydraulic ram. This application requires two main valves and control systems as described above, one coupled between the fluid source and the hydraulic ram, and the other coupled between the hydraulic ram and the fluid sink. In this case, the lirst mentioned valve would influence the rate of the elevator cabs ascent, and the other would inlluence the rate of the elevator cabs descent. In this application, a two inch size for the main valve of this invention has been found appropriate in connection with a six inch main valve in the existing elevator control system. The main valve of this invention could also be used as a replacement for the main valve of an existing elevator control system, but this, of course, would require a six inch valve rather than a two inch valve.

From the foregoing description, it will be apparent that this invention provides a hydraulic valve and valve control which fullls the objectives set forth in the opening paragraphs of this document. It will be equally apparent that this invention is by no means limited to the specilic edmodiment disclosed herein, since many modifications can be made in the disclosed structure without departing from the basic teaching of this patent application. For example, the uid input to the valve control means could be derived from an independent source if desired rather than being tapped from lluid whose ilow is being controlled. This would allow the invention to beused to control the-flow of air without the bouncing or overshoot that would result from the use of compressed air in the embodiment disclosed. The leather packings in the disclosed embodiment could be replaced by piston rings if desired, and many other piston assemblies could be used vention will be apparent to those skilled in the art, and this invention includes all modifications falling within the scope of the following claims.

I claim:

1. A hydraulic valve and control means therefor comprising a valve body having a piston member slideably mounted therewithin and movable between first and second limiting positions, a first fluid chamber within said valve body in fiuid communcation with one end of said piston member, a second fiuid chamber within said valve body in fluid communication with the opposite end of said piston member, a fluid inlet port and a fluid outlet port communicating into said second fiuid chamber, means coupled to said piston member for variably obstructing the passage of fiuid between said inlet and outlet ports in accordance with the position of said piston member, a third port communicating into said first fiuid chamber, and means for forcing fiuid into and out of said first uid chamber via said third port and sealing said fluid to position said piston at any desired position between said first and second limiting positions, thereby producing any desired rate of fluid flow between said inlet and said outlet ports between a minimum rate defined by one of said limiting positons of said piston and a maximum rate defined by the other limiting position thereof, the area of one end of said piston is larger than the area of the other end thereof, whereby equal pressures in said first and second fiuid chambers produce differing forces on opposite ends of said piston member, said larger area of said piston comprising the end thereof in fluid communication with said rst fiuid chamber, whereby equal pressures in said first and second fluid chambers produces a force differential urging said piston member away from said rst fiuid chamber and toward said second uid chamber; and means for forcing fluid into and out of said first fluid chamber comprising a first fluid coupling including a normally open solenoid valve coupled between said third port and one of the other.

two ports, and a second fluid coupling including a first normally closed solenoid valve coupled between said third port and a fluid sink, means for closing said normally open valve, and means for opening said rst normally closed valve, and a third uid coupling including a second normally-closed solenoid valve coupled between said third port and said one of the other two ports, and means for opening said second normally-closed valve.

2. The combination defined in claim 1 wherein movement of said piston member toward said second fluid chamber increases the obstruction offered by said means coupled to said piston member for variably obstructing the passage of fiuid between said inlet and outlet ports, whereby movement of said piston member toward said second uid chamber decreases the rate of fluid flow between said inlet and outlet ports, and movement of said piston member toward said first fluid chamber increases the rate of fluid flow between said inlet and said outlet ports.

3. The Acombination defined in claim 2 wherein saidr normally open and normally closed valves are solenoid operated valves, and also including a valve control circuit for energizing and dre-energizing said solenoid valves in response to input signals signifying a desired fiuid fiow rate between the inlet and outlet ports of said hydraulic valve.

4. The combination defined in claim 3 wherein said valve control circuit is adapted to receive ofi on, increase, and decrease signals, said valve control circuit -being operable to de-energize all of said solenoid valves in response to said off signal, and being operable to energize said normally open valve and said first normally closed valve in response to said on signal, and being operable to energize said normally open valve and said second normally closed valve in response to said decrease signal, and being operable to energize said normally open valve and said first normally closed valve in response to said increase signal, and said Valve control signal being operable to hold said normally open valve energized following the application of an increase or decrease signal until an off signal is applied thereto.

5. The combination defined in claim 1 and also including first, second, and third choke valves coupled in a corresponding one of said first, second, and third fluid couplings.

References Cited by the Examiner UNITED STATES PATENTS 824,658 6/1906 Junggren 251-30 2,375,946 5/1945 Reichelt 91-32 X 2,635,634 4/1953 Thurber 251-26 2,737,197 3/1956 Jaseph 251-30 X 2,999,482 9/1961 Bower 91-31 3,075,737 l/l963 Cantalupo 251-26 M. CARY NELSON, Primary Examiner.

A. ROSENTHAL, Assistant Examiner.

Claims (1)

1. A HYDRAULIC VALVE AND CONTROL MEANS THEREFOR COMPRISING A VALVE BODY HAVING A PISTON MEMBER SLIDEABLY MOUNTED THEREWITHIN AND A MOVABLE BETWEEN FIRST AND SECOND LIMITING POSITIONS, A FIRST FLUID CHAMBER WITHIN SAID VALVE BODY IN FLUID COMMUNICATION WITH ONE END OF SAID PISTON MEMBER, A SECOND FLUID CHAMBER WITHIN SAID VALVE BODY IN FLUID COMMUNICATION WITH THE OPPOSITE END OF SAID PISTON MEMBER, A FLUID INLET PORT AND A FLUID OUTLET PORT COMMUNICATING INTO SAID SECOND FLUID CHAMBER, MEANS COUPLED TO SAID PISTON MEMBER FOR VARIABLY OBSTRUCTING THE PASSAGE TO FLUID BETWEEN SAID INLET AND OUTLET PORTS IN ACCORDANCE WITH THE POSITION OF SAID PISTON MEMBER, A THIRD PORT COMMUNICATING INTO SAID FIRST FLUID CHAMBER, AND MEANS FOR FORCING FLUID INTO AND OUT OF SAID FIRST FLUID CHAMBER VIA SAID THIRD PORT AND SEALING SAID FLUID TO POSITION SAID PISTON AT ANY DESIRED POSITION BETWEEN SAID FIRST AND SECOND LIMITING POSITIONS, THEREBY PRODUCING ANY DESIRED RATE OF FLUID FLOW BETWEEN SAID INLET AND SAID OUTLET PORTS BETWEEN A MINIMUM RATE DEFINED BY ONE OF SAID LIMITING POSITIONS OF SAID PISTON AND A MAXIMUM RATE DEFINED BY THE OTHER LIMITING POSITION THEREOF, THE AREA OF ONE END OF SAID PISTON IS LARGER THAN THE AREA OF THE OTHER END THEREOF, WHEREBY EQUAL PRESSURES IN SAID FIRST AND SECOND FLUID CHAMBERS PRODUCE DIFFERING

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