GB2025579A

GB2025579A - Hydraulic restrictor valve

Info

Publication number: GB2025579A
Application number: GB7919811A
Authority: GB
Original assignee: Newman Tonks Ltd
Current assignee: Allegion UK Ltd
Priority date: 1978-07-13
Filing date: 1979-06-07
Publication date: 1980-01-23
Also published as: GB2025579B

Abstract

A flow control valve comprising an externally stepped outer member (25) having its smaller diameter part externally screw-threaded (27) for engagement with a complementary screw thread (24) in a bore (23) in a body (10) in which the valve is received, in use, to allow axial adjustment therein. The outer member (25) has an interior cavity (30) which is closed at one end by a screw (31), by means of which said axial adjustment can be made, and has an opening at its other end, said cavity also communicating with the bore by way of a further passage (33) at a position adjacent the step in the outer member. The cavity has a portion (32) tapered towards said opening at its end and a valve (26) loosely located within the outer member has a taper complementary to that within the cavity. In one direction of flow through the valve, the separation of the outer and valve member tapers is maximised to allow unrestricted flow, whilst in the other direction of flow such separation is minimised to restrict the flow. The valve has particular application in a door closer, to allow opening of the door substantially without restriction, and substantial restriction during closing. <IMAGE>

Description

SPECIFICATION Flow control valve This invention relates to flow control valves for liquids. In particular the invention is concerned with flow control valves for use in hydraulic units for allowing hydraulic fluid to flow past a piston as this is moved along a fluid filled cylinder.

Such a hydraulic unit, for which the valve of the invention is particularly developed, is a hydraulically operated door closer. In such a door closer it is required that the fluid in the cylinder should flow past the piston in one direction substantially without restriction, so that the door can be opened substan tiallywithout resistance, but movement of the piston in the opposite direction should be resisted to retard the action of springs tending to close the door.

In conventional door closers, the free movement of the piston in one direction, is permitted by a non return valve, often mounted in the piston, whereas the restricted flow for retarding closing of the door is provided by a valve, often in a passage bypassing the piston, this valve having an orifice containing a tapered needle or equivalent part. To permit adjustment of the size of the orifice available for flow, and therefore the degree of restriction offered, the axial position of the needle is adjustable to vary the degree of entry into the orifice.

This type of valve is subject to silting with dirt which gradially builds up to create more restriction.

Furthermore, the non return valve, which may be a ball valve, is liable to leakage if any dirt becomes lodged in it.

It is an object of this invention to provide a flow control valve, particularly suitable for this and analogous purposes, which reduces the risk of incorrect function due to build up of dirt and which is moreover effective in normal use.

According to the invention a flow control valve comprises an outer member adapted for axial adjustment in a bore in a body in which it is to be used, the outer member defining an interior cavity, the member having an opening at one end into the cavity, and a further opening at a position intermediate the ends of the member and communicating with the cavity, the cavity having a portion tapered towards the opening at the end of the member and a valve member loosely located within the outer member having a taper complementary to that within the cavity, and the valve member being arranged to engage stop means in use, which limit its axial movement within the outer member, whereby, in one axial extremity of the permitted movement, the separation of the outer and valve member tapers is maximised and at the opposite extremity it is minimised, in accordance with the axially adjusted position of the outer member within its bore, in use.

A further object is to provide a door closer which is efficient in operation and in which the risk of incorrect functioning is minimised.

According to this aspect the invention provides a door closer including a body defining a cylinder, a piston slidably mounted in the cylinder, the cylinder, in use containing hydraulic fluid, and a valve arranged in a passage to permit flow of fluid in both directions between the spaces within the cylinder at opposite sides of the piston, the valve permitting flow in one direction, substantially without restriction and flow in the other direction being restricted by pressure of the fluid acting on a movable valve member of the valve to move it into a position to restrict an orifice in the valve through which, in use, the fluid must flow.

Preferably, the valve is provided with an outer member mounted in a bore, and having provision for adjustment axially in the bore, the outer member having, at one end, said orifice providing communication between a cavity within the outer member and a passage to the bore, and, intermediate its ends the outer member has a further opening providing communication between the cavity and further passage to the bore, a valve member being loosely located within the cavity and the outer member and said valve member having complementary tapers, the arrangement being such that the valve member can move axially within the cavity between a limit position in which separation of the tapers on the outer and valve members is maximised and a further limit position in which it contact an adjacent surface in the bore, through the opening in the end of the outer member in which the separation of the tapers is minimised, in accordance with the adjusted position of the outer member in the bore.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic fragmentary view of one end of a door closer incorporating a flow control valve in accordance with the invention; Figure 2 is a cross sectional view on the line 2-2 in Figure 1; Figure 3 is an enlarged cross sectional view similar to Figure 2 with a valve member in one limit position, and Figure 4 is a similar view to Figure 3 with the valve member in the opposite limit position.

Figure 1 shows a door closer device having a body 10 defining a cylinder 11. Slidably mounted within the cylinder is a piston 12 carried on a piston rod 13.

One end of the cylinder 11 is closed by a plug 1 la and the other end (not illustrated) is also closed.

Acting against a plug or equivalent member at the other end of the cylinder 11 is a bank of springs 14 which urge the piston 12 towards the end at which the plug lia is fitted.

The piston is connected to a system of levers attached, in use, to a door so that opening and closing movement of the door is accompanied by axial movement of the piston 12 within the cylinder 11. The lever system is not illustrated and is of conventional kind.

The cylinder 11 is filled with fluid, such as oil, which therefore occupies the spaces at both sides of the piston 12. The piston has sealing means substantially preventing leakage between it and the cylinder wall.

The travel of the piston 12 within the cylinder is relatively short and is between two lateral drillings 15 16 in the body 10 and opening into the cylinder 11. Each such drilling is closed by a screw 17, 18 respectively in the body 10.

Communicating with the drilling 15 is a drilling 19 extending parallel with the axis of the cylinder 11.

Communicating with the drilling 16 is a further drilling 20 parallel with the axis of the cylinder 11 and spaced from the drilling 19. These two drillings 19 and 20 are closed at one end by respective screws 21,22 in the body 10. These screws 21,22 and the screws 17, 18 may be replaced by other plugs fixed in conventional manner. The arrangement of these screws is seen in Figures 1 and 2.

It can be seen from these figures that the drillings 19 and 20 both break into a wider bore 23 in the body 10. This bore contains a valve which permits flow from the drilling 15 to the drilling 16 and therefore between the spaces at opposite sides of the piston 12 as the piston moves in the cylinder.

The bore 23 is closed ended and at its closed end it breaks into the drilling 19. The drilling 20 enters the bore at a position between the closed end of the bore and its open end at one face of the body 10. between the drilling 2O and its closed end, the bore 23 is screw threaded as indicated at 24 whereas between the drilling 20 and the outer end of the bore 23 this is of plain cylindrical form.

Contained within the bore 23 the valve includes an outer member 25 and an inner valve member 26, in the form of a tapered needle.

The outer member 25 is stepped having, near one end, an externally screw threaded portion 27. This is engageable with the screw thread 24 in the bore 23 to allow the outer member to be adjusted axially within the bore. The outer end of the member 25 is of larger diameter than the screw threaded portion thereof and has an external annular groove 28 containing a seal 29 providing a leak-proof joint with the wall of the bore 23.

Defined within the outer member 25 is a cavity 30.

The outer end of this cavity is closed by a countersunk head plug 31. This is in the form of a short screw engaged in a complementary screw thread in the outer member 25 but adhesive is applied to the screw threads so that once engaged, the screw will remain fixed in the outer member 25. It is intended that after assembly these parts should always move together. The outer face of the head of the screw 31 is slotted to provide engagement for a screw driver whereby the screw 31 together with the outer member 25 can be rotated. Such rotation provides axial adjustment of the position of the menber 25 within the bore 23 by means of the screw threads 24 and 27.

The cavity 30 at its opposite end has a tapered portion 32 which extends towards the inner end of the outer member 25. This tapered portion 32 starts between the entry of the drilling 20 to the bore 23.

In the side of the outer member 25 of the valve there are radial ports 33 which allow communication between the cavity 30 within the outer member 25 and the drilling 20 in the body 10 through space defined between the exterior of the outer member 25 and the bore 23. Such space is identified by numeral 34. This space 34 communicates with the drilling 20 in all axially adjusted positions of the outer member 25 in the bore 23.

Loosely located within the cavity 30 of the outer member 25 is the valve member 26. Its narrow end is towards the closed end of the bore 23.

The taper on the exterior of this needle 26 is complementary to the taper 32 in the cavity 30.

Figures 3 and 4 show the limit positions which the needle 26 can occupy. In Figure 3 the needle extremity is shown in contact with the end of the bore 23 at 35. In this position, the tapers of the outer member 25 and of the valve member 26 are close together though not actually in contact. The separation between them is governed bythe axial position of the outer member 25 within the bore 23. In this position, flow of fluid from the drilling 20 to the drilling 19 as indicated by the arrows is substantially restricted. The pressure of the fluid acts on the and of the valve member 26 to maintain it in contact at the point 35 with the closed end of the bore 23.

Figure 4, however shows the opposite limit position for the valve member 26 in which its wider end is in contact with the screw 31. In this position, the separation of the tapers of the outer member 25 and the valve member 26 is maximised. Thus, flow of fluid between the drilling 19 and the drilling 20 as indicated by the arrows is substantially without restriction.

In the piston and cylinder unit shown in Figure 1 the piston 12 is permitted to move in the cylinder 11 in the directon away from the plug 1 la substantially without restriction. This is the direction accompanying opening movement of the door.

However, movement of the piston in the opposite direction under the influence of the spring bank 14 is substantially restricted because the fluid must pass through the barrow separation between the tapers of the outer member 25 and of the valve member 26 as shown in Figure 3.

In operation, the reciprocation of the valve member 26 in the bore 23, the unrestricted and thus fast flow of fluid in one direction past the valve member, and the surging effect of the fluid as it flows both ways over the valve member, ensure that the valve is kept clean and clear from dirt, so as to produce a constant checking speed, i.e. closing time, when closing a door. Thus the mentioned disadvantages of dirt build up with prior art valves is overcome.

Moreover the need forfilteration of the fluid is also eliminated.

In an alternative construction the valve could disposed in the piston.

CLAIMS 4 1. A flow control valve comprising an outer member adapted for axial adjustment in a bore in a body in which it is to be used, the outer member defining an interior cavity, the member having an opening at one end into the cavity, and a further opening at a position intermediate the ends of the member and communicating with the cavity, the cavity having a portion tapered towards the opening at the end of the member and a valve member loosely located within the outer member having a taper complementary to that within the cavity, and

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. 11. Each such drilling is closed by a screw 17, 18 respectively in the body 10. Communicating with the drilling 15 is a drilling 19 extending parallel with the axis of the cylinder 11. Communicating with the drilling 16 is a further drilling 20 parallel with the axis of the cylinder 11 and spaced from the drilling 19. These two drillings 19 and 20 are closed at one end by respective screws 21,22 in the body 10. These screws 21,22 and the screws 17, 18 may be replaced by other plugs fixed in conventional manner. The arrangement of these screws is seen in Figures 1 and 2. It can be seen from these figures that the drillings 19 and 20 both break into a wider bore 23 in the body 10. This bore contains a valve which permits flow from the drilling 15 to the drilling 16 and therefore between the spaces at opposite sides of the piston 12 as the piston moves in the cylinder. The bore 23 is closed ended and at its closed end it breaks into the drilling 19. The drilling 20 enters the bore at a position between the closed end of the bore and its open end at one face of the body 10. between the drilling 2O and its closed end, the bore 23 is screw threaded as indicated at 24 whereas between the drilling 20 and the outer end of the bore 23 this is of plain cylindrical form. Contained within the bore 23 the valve includes an outer member 25 and an inner valve member 26, in the form of a tapered needle. The outer member 25 is stepped having, near one end, an externally screw threaded portion 27. This is engageable with the screw thread 24 in the bore 23 to allow the outer member to be adjusted axially within the bore. The outer end of the member 25 is of larger diameter than the screw threaded portion thereof and has an external annular groove 28 containing a seal 29 providing a leak-proof joint with the wall of the bore 23. Defined within the outer member 25 is a cavity 30. The outer end of this cavity is closed by a countersunk head plug 31. This is in the form of a short screw engaged in a complementary screw thread in the outer member 25 but adhesive is applied to the screw threads so that once engaged, the screw will remain fixed in the outer member 25. It is intended that after assembly these parts should always move together. The outer face of the head of the screw 31 is slotted to provide engagement for a screw driver whereby the screw 31 together with the outer member 25 can be rotated. Such rotation provides axial adjustment of the position of the menber 25 within the bore 23 by means of the screw threads 24 and 27. The cavity 30 at its opposite end has a tapered portion 32 which extends towards the inner end of the outer member 25. This tapered portion 32 starts between the entry of the drilling 20 to the bore 23. In the side of the outer member 25 of the valve there are radial ports 33 which allow communication between the cavity 30 within the outer member 25 and the drilling 20 in the body 10 through space defined between the exterior of the outer member 25 and the bore 23. Such space is identified by numeral 34. This space 34 communicates with the drilling 20 in all axially adjusted positions of the outer member 25 in the bore 23. Loosely located within the cavity 30 of the outer member 25 is the valve member 26. Its narrow end is towards the closed end of the bore 23. The taper on the exterior of this needle 26 is complementary to the taper 32 in the cavity 30. Figures 3 and 4 show the limit positions which the needle 26 can occupy. In Figure 3 the needle extremity is shown in contact with the end of the bore 23 at 35. In this position, the tapers of the outer member 25 and of the valve member 26 are close together though not actually in contact. The separation between them is governed bythe axial position of the outer member 25 within the bore 23. In this position, flow of fluid from the drilling 20 to the drilling 19 as indicated by the arrows is substantially restricted. The pressure of the fluid acts on the and of the valve member 26 to maintain it in contact at the point 35 with the closed end of the bore 23. Figure 4, however shows the opposite limit position for the valve member 26 in which its wider end is in contact with the screw 31. In this position, the separation of the tapers of the outer member 25 and the valve member 26 is maximised. Thus, flow of fluid between the drilling 19 and the drilling 20 as indicated by the arrows is substantially without restriction. In the piston and cylinder unit shown in Figure 1 the piston 12 is permitted to move in the cylinder 11 in the directon away from the plug 1 la substantially without restriction. This is the direction accompanying opening movement of the door. However, movement of the piston in the opposite direction under the influence of the spring bank 14 is substantially restricted because the fluid must pass through the barrow separation between the tapers of the outer member 25 and of the valve member 26 as shown in Figure 3. In operation, the reciprocation of the valve member 26 in the bore 23, the unrestricted and thus fast flow of fluid in one direction past the valve member, and the surging effect of the fluid as it flows both ways over the valve member, ensure that the valve is kept clean and clear from dirt, so as to produce a constant checking speed, i.e. closing time, when closing a door. Thus the mentioned disadvantages of dirt build up with prior art valves is overcome. Moreover the need forfilteration of the fluid is also eliminated. In an alternative construction the valve could disposed in the piston. CLAIMS 4

1. A flow control valve comprising an outer member adapted for axial adjustment in a bore in a body in which it is to be used, the outer member defining an interior cavity, the member having an opening at one end into the cavity, and a further opening at a position intermediate the ends of the member and communicating with the cavity, the cavity having a portion tapered towards the opening at the end of the member and a valve member loosely located within the outer member having a taper complementary to that within the cavity, and

the valve member being arranged to engage stop means in use, which limits its axial movement within the outer member, whereby, in one axial extremity of the permitted movement, the separation of the outer and valve member tapers is maximised and at the opposite extremity it is minimised, in accordance with the axially adjusted position of the outer member within its bore, in use.

2. Avalve as claimed in Claim 1 wherein said outer member is stepped to provide a smaller diameter portion which is externally screw threaded to engage, in use, with a complementary screw thread of said bore, to allow axial adjustment of said outer member in said bore.

3. A valve as claimed in Claim 2 wherein the larger diameter portion of said stepped outer member is cylindrical and sealing engages, in use, in said bore, said larger diameter portion having a screw threaded hole therein in which is secured a screw, so that rotation of the screw, in use, causes corresponding rotation of said outer member and thus axial adjustment movement thereof in said bore.

4. A valve as claimed in Claim 3 wherein said stop means at said one axial extremity, where the separation of the outer end valve member tapers is maximised is said screw secured in the hole in said cylinder portion of the outer member.

5. A valve means as claimed in any one of claims 1 to 4 wherein the stop means at the other axial extremity, where the separation of the outer end valve member tapers is minimised, is a closed end of the bore in which the outer member is disposed, in use.

6. A valve means as claimed in any one of claims 1 to 5 wherein said further opening extends through the smaller diameter portion of said outer member at a position adjacent the step therein, and communicateswith a space defined, in use, between the external surface of said smaller diameter portion and the surface of the bore in which the outer member is disposed.

7. Avalve means as claimed in any one of the preceding claims wherein said valve member is a tapered needle, the narrow end of which is directed to a closed end of the bore.

8. A door closer including a body defining a cylinder, a piston slidably mounted in the cylinder, the cylinder, in use containing hydraulic fluid, and a yalve arranged in a passage to permit flow of fluid in both directions between the spaces within the cylinder at opposite sides of the piston, the valve permitting flow in one direction, substantially without restriction and flow in the other direction being restricted by pressure of the fluid acting on a movable valve member of the valve to move it into a position to restrict an orifice in the valve through which, in use, the fluid must flow.

9. A door closer as claimed in Claim 8 wherein the valve is provided with an outer member mounted in a bore, and having provision for adjustment axially in the bore, the outer member having, at one end, said orifice providing communication between a cavity within the outer member and a passage to the bore, and, intermediate its ends the outer member has a further opening providing communication between the cavity and further passage to the bore, a valve member being loosely located within the cavity and the outer member and said valve member having complementary tapers, the arrangement being such that the valve member can move axially within the cavity between a limit position in which separation of the tapers on the outer and valve members is maximised and a further limit position in which it contacts an adjacent surface in the bore, through the opening in the end of the outer member in which the separation of the tapers is minimised, in accordance with the adjusted position of the outer member in the bore.

10. A door closer as claimed in Claim 8 or 9 wherein said outer member is stepped to provide a smaller diameter portion which is externally screw threaded and engaged with a complementary screw threaded portion of said bore, to allow axial adjustment of said outer member in said bore.

11. A door closer as claimed in Claim 10 wherein the larger diameter portion of said stepped outer member is cylindrical and sealing engages, in use, in said bore, said larger diameter portion having a screw threaded hole therein in which is secured a screw, so that rotation of the screw, in use, causes corresponding rotation of said outer member and thus axial adjustment movement thereof in said bore.

12. A door closer as claimed in Claim 11 wherein when fluid flows through the valve substantially without restriction, in use, said valve member is forced against said screw secured in the hole in said cylindrical portion of the outer member, which thus acts as a stop means.

13. A door closer as claimed in any one of claims 8 tol 2 wherein said valve member bears against a closed end of said bore when flow through the valve, in use, is restricted.

14. A door closer as claimed in any one of claims 9 to 13 wherein said further opening extends through the smaller diameter portion of said outer member at a position adjacent the step therein, and communicates with a space defined between the external surface of said smaller diameter portion and the surface of said bore.

15. A door closer as claimed in any one of claims 8 to 14 wherein said valve member is a tapered needle, the narrow end of which is directed to a closed end of the bore.

16. A door closer as claimed in any one of claims 9 to 15 wherein said bore is provided in said body of the door closer, said passage to the bore extending parallel to the axis of the cylinder, and communicating with a lateral passage which itself communicates directly with the space in the cylinder at one side of the piston, said further passage to the bore also extending parallel to the cylinder axis and communicating with a further lateral passage which itself communicates with the space in the cylinder at the other side of the piston, the two lateral passages being spaced apart axially by a distance greater than the piston travel, in use.

17. A door closer as claimed in any one of claims 8 to 16 wherein the reciprocation of the movable valve member and the flow of hydraulic fluid past said valve member in both directions, in use, serve automatically to keep to the valve clean.

18. A flow control valve substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

19. A door closer incorporating a flow control valve substantially as hereinbefore described with reference to and as shown in the accompanying drawings.