GB2180324A

GB2180324A - Flow controller

Info

Publication number: GB2180324A
Application number: GB08621886A
Authority: GB
Inventors: Bernd Sonje
Original assignee: Joh Vaillant GmbH and Co
Current assignee: Vaillant GmbH
Priority date: 1985-09-12
Filing date: 1986-09-11
Publication date: 1987-03-25
Also published as: DE3628899A1; IT209612Z2; IT8622931V0; DE8526293U1; FR2587130A1; BE905376A; GB8621886D0; NL8602261A; DE3628899C2; AT392853B; GB2180324B; CH670523A5; ATA231486A

Abstract

A flow controller, especially but not exclusively for maintaining a constant rate of water supply to a water heater, comprises a spring-loaded control piston (1) which is moveable in a guide sleeve (4) through which fluid flows. The guide sleeve (4) has at least one radial inlet opening (3). The guide sleeve (4), the control piston (1) moveably mounted in the guide sleeve (4), and a closing cover (8) which serves as a spring abutment constitute a unit which is replaceably fitted in a mating cavity (5) of the flow path. The sleeve (4) is joined by a screw or snap connection to a cap 13 which defines a valve seat. <IMAGE>

Description

SPECIFICATION Flow controller This invention relates to a flow controller, especially but not exclusively for maintaining a constant rate of water supply to a water heater, comprising a spring-loaded control piston, which is moveable in a guide through which fluid flows.

It is an aim of the invention to simplify the structure, operation and maintenance of such a flow controller and to facilitate its replacement in case of need.

Accordingly, the present invention is directed to a flow controller as set out in the opening paragraph of this specification, in which the guide has at least one radial inlet opening and the guide, the control piston moveably mounted in the guide, and a closing cover which serves as a spring abutment constitute a unit, which is replaceably fitted in a mating cavity of the flow path.

In a preferred embodiment of the invention the guide comprises a cylindrical sleeve, which is preferably made of a synthetic plastics material and has radial inlet openings and which at that end which faces the closing cover carries a seal for the control piston, and the sleeve is adapted to be fixed by means of the cover and preferably by a screw joint at the open end of the cavity which accommodates the unit.

In that case that end of the sleeve which is opposite to the cover may bear on an abutment which is provided in the cavity and which forms a valve seat co-operating with the tapered adjacent portion of the control piston.

The guide and the abutment may be accommodated, if desired, in a housing, which encloses the unit.

Three examples of a flow controller made in accordance with the present invention are shown diagrammatically in the accompanying drawings, in which Figs. 1 to 3 are respective axial sectional views of the three examples.

In Fig. 1, a control piston 1 comprises a solid of revolution which has a diameter that varies in a particular manner over the length of the piston. The piston comprises a cylindrical portion, which is guided in an annular seal 2, a portion which is reduced in diameter and is positioned adjacent to radial inlet openings 3 of the sleeve 4 and of an upper cap 13, and a tapered portion, which has a curved cross section to define a valve gap 7 of variable size with an abutment 6, which is disposed in a cavity 5 of the flow path.

The control piston 1 is biased by a spring 9, which bears on a screw-threaded cover 8, by which the unit comprising the parts stated is retained in one part of the cavity 5, which constitutes a portion of the flow path. That unit may be enclosed in a housing 10 (shown in Figs. 2 and 3). The sleeve 4 is urged against the abutment 6 in sealing contact therewith.

Water, for example, to be supplied at a constant flow rate flows through an inlet 11 into the cavity 5 and from the annular clearance defined between the sleeve 4 (or the upper cap 13) and the housing 10 or the inside surface of the cavity enters the sleeve 4 through one or more openings 3. In dependence upon the current size of the valve gap 7 the water is delivered through the outlet line 12 to the appliance to be supplied, for example, to a water heater. The flow rate is automatically kept constant owing to the hydraulically effective shape of the control piston 1 moving in the sleeve 4 under the action of the flow pressure and of the spring 9.

In the two embodiments of the invention shown in Figs. 2 and 3, the guide sleeve 4, preferably made of a synthetic plastics material, comprises two parts and may comprise an upper cap 13 that is made of a more wear-resistant material, such as metal, and constitutes a seat for the controller. That seat may be clipped to the guide sleeve 4 in one embodiment (Fig. 2) and may be screw-connected to the guide sleeve 4 in the other embodiment (Fig. 3). The upper caps 13 serve to avoid erosion damage caused by the flowing fluid and are also provided with radial inlet openings.

1. A flow controller, especially but not exclusively for maintaining a constant rate of water supply to a water heater, comprising a spring-loaded control piston, which is moveable in a guide through which fluid flows, in which the guide has at least one radial inlet opening and the guide, the control piston moveably mounted in the guide, and a closing cover which serves as a spring abutment constitute a unit, which is replaceably fitted in a mating cavity of the flow path.

2. A flow controller according to claim 1, in which the guide comprises a cylindrical sleeve, which is preferably made of a synthetic plastics material and has radial inlet openings and which at that end which faces the closing cover carries a seal for the control piston, and the sleeve is adapted to be fixed by means of the cover and preferably by a screw joint at the open end of the cavity which accommodates the unit.

3. A flow controller according to claim 2, in which that end of the sleeve which is opposite to the cover bears on an abutment which is provided in the cavity and which forms a valve seat cooperating with a tapered adjacent portion of the control piston.

4. A flow controller according to claim 3, further comprising a housing which encloses the guide and the abutment.

5. A flow controller according to claim 4,

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Flow controller This invention relates to a flow controller, especially but not exclusively for maintaining a constant rate of water supply to a water heater, comprising a spring-loaded control piston, which is moveable in a guide through which fluid flows. It is an aim of the invention to simplify the structure, operation and maintenance of such a flow controller and to facilitate its replacement in case of need. Accordingly, the present invention is directed to a flow controller as set out in the opening paragraph of this specification, in which the guide has at least one radial inlet opening and the guide, the control piston moveably mounted in the guide, and a closing cover which serves as a spring abutment constitute a unit, which is replaceably fitted in a mating cavity of the flow path. In a preferred embodiment of the invention the guide comprises a cylindrical sleeve, which is preferably made of a synthetic plastics material and has radial inlet openings and which at that end which faces the closing cover carries a seal for the control piston, and the sleeve is adapted to be fixed by means of the cover and preferably by a screw joint at the open end of the cavity which accommodates the unit. In that case that end of the sleeve which is opposite to the cover may bear on an abutment which is provided in the cavity and which forms a valve seat co-operating with the tapered adjacent portion of the control piston. The guide and the abutment may be accommodated, if desired, in a housing, which encloses the unit. Three examples of a flow controller made in accordance with the present invention are shown diagrammatically in the accompanying drawings, in which Figs. 1 to 3 are respective axial sectional views of the three examples. In Fig. 1, a control piston 1 comprises a solid of revolution which has a diameter that varies in a particular manner over the length of the piston. The piston comprises a cylindrical portion, which is guided in an annular seal 2, a portion which is reduced in diameter and is positioned adjacent to radial inlet openings 3 of the sleeve 4 and of an upper cap 13, and a tapered portion, which has a curved cross section to define a valve gap 7 of variable size with an abutment 6, which is disposed in a cavity 5 of the flow path. The control piston 1 is biased by a spring 9, which bears on a screw-threaded cover 8, by which the unit comprising the parts stated is retained in one part of the cavity 5, which constitutes a portion of the flow path. That unit may be enclosed in a housing 10 (shown in Figs. 2 and 3). The sleeve 4 is urged against the abutment 6 in sealing contact therewith. Water, for example, to be supplied at a constant flow rate flows through an inlet 11 into the cavity 5 and from the annular clearance defined between the sleeve 4 (or the upper cap 13) and the housing 10 or the inside surface of the cavity enters the sleeve 4 through one or more openings 3. In dependence upon the current size of the valve gap 7 the water is delivered through the outlet line 12 to the appliance to be supplied, for example, to a water heater. The flow rate is automatically kept constant owing to the hydraulically effective shape of the control piston 1 moving in the sleeve 4 under the action of the flow pressure and of the spring 9. In the two embodiments of the invention shown in Figs. 2 and 3, the guide sleeve 4, preferably made of a synthetic plastics material, comprises two parts and may comprise an upper cap 13 that is made of a more wear-resistant material, such as metal, and constitutes a seat for the controller. That seat may be clipped to the guide sleeve 4 in one embodiment (Fig. 2) and may be screw-connected to the guide sleeve 4 in the other embodiment (Fig. 3). The upper caps 13 serve to avoid erosion damage caused by the flowing fluid and are also provided with radial inlet openings. CLAIMS

5. A flow controller according to claim 4, in which the sleeve is surrounded by an upper cap, which is made of wear-resistant material, such as metal.

6. A flow controller according to claim 5, having a snap joint or clipped joint connecting the sleeve to the upper cap.

7. A flow controller according to claim 5, having a screw joint connecting the sleeve to the upper cap.