GB2093955A

GB2093955A - Fluid flow controlling valves

Info

Publication number: GB2093955A
Application number: GB8205463A
Authority: GB
Original assignee: Clearplas Ltd
Current assignee: Clearplas Ltd
Priority date: 1981-02-25
Filing date: 1982-02-24
Publication date: 1982-09-08

Abstract

In a valve member of the kind having a substantially rigid body part 11 and a flexible wiper seal 12 extending around the periphery or a portion of the periphery of the body part, the wiper seal is moulded around the periphery of a portion of the periphery of the body part which is pre-formed The wiper seal is keyed by an integral portion thereof moulded into an aperture in or around a projection on the pre-formed body part. The body portion 11 may have slot 14 preformed therein into which portions 15 moulded integrally with the wiper seal 12 extend and thereby form the key. <IMAGE>

Description

SPECIFICATION Fluid Flow Controlling Valves The invention relates to valves for controlling fluid flow and is particularly, but not exclusively, concerned with air-flowvalves for ventilating the interiors of motor vehicles, aircraft or boat cabins or other closed spaces.

Valves of this kind as used in motor vehicles either comprise a part-spherical or "eye-ball" type of tubular air deflector member universally movable in a housing of complementary shape or a cylindrical type of tubular air deflector member containing air deflector vanes and movable about its longitudinal axis in a housing having a rectangular air opening. Such valves may also include air obturating, pivotally-mounted flaps either positioned in the housing upstream of the deflector member or mounted within the deflector member itself. The periphery of such a flap, or a portion of its periphery, in the closed position of the flap may sealingly engage with the interior of the housing or deflector member, as appropriate, and thus it is known to provide a flexible wiper seal around the periphery, or a portion thereof, of a rigid, pivotally-mounted flap for that purpose.

One known way of providing the peripheral or part-peripherai flexible wiper seal on a rigid flap is to construct the flap in two superimposed layers with the flexible wiper seal gripped therebetween and extending outwardly from the periphery of the layers. Where the layers and the seal are made of moulded plastics materials, three separate moulds would be required and furthermore the three separately-formed parts would then have to be assembled to form the complete flap.

An object of the invention is to mould a flexible wiper seal around the periphery or a portion thereof of a preformed flap or other rigid valve member.

According to the invention a method of manufacturing a valve member comprises preforming a rigid or substantially rigid body part of the valve member and then moulding around the periphery or a portion of the periphery of said body part a flexible, peripherally-extending wiper seal which also extends outwardly from the periphery of said body part and which on setting or curing becomes attached to said body part of the valve member.

The pre-formed body part may have an aperture formed therein or a projection formed thereon, into which aperture or around which projection the moulding material from which the wiper seal is formed will flow and which on setting will form a key which will hold the wiper seal from separation from said body part. The aperture or projection may conveniently have an under-cut portion into or around which the moulding material from which the wiper seal is formed will flow and set, thereby to produce a key having a retaining portion located in the under-cut portion of said body part.

The two moulding steps as aforesaid may be performed in a simple moulding machine having two moulding stations in each of which a respective moulding step is performed or in two moulding machines in each of which a respective moulding step is performed.

The invention also includes a valve member comprising said body part and a flexible wiper seal which is moulded on said body part by a method as set out in any of the three immediately preceding paragraphs.

The valve member may be a flap valve comprising a body part and the flexible wiper seal which is moulded around the periphery or a portion of the periphery of said body part. The flap valve, as viewed in elevation, may have any required shape. For example, it may be circular, semi-circular or rectangular, as viewed in elevation.

Alternatively, the valve member may be a tubular air deflector member as aforesaid, and may be formed with a peripherally and outwardlyextending flexible wiper seal moulded on the deflector member or a rigid part thereof to engage against the interior surface of a seating or housing in which the deflector member is mounted.

By way of example, two alternative circular or part-circular air-obturating flaps for air-controlling and deflector valves for use in motor vehicles are now described by way of example of the invention, with reference to the accompanying drawings, in which: Figure 1 is a diametral section through the first flap; Figure 2 is an elevation of part of the second flap; Figure 3 is a radial section on the line AA in Figure 2, and Figure 4 is a radial section on the line BB in Figure 2.

In each case, the circular or part-circular body part of the flap is moulded from a synthetic plastics material which will be rigid or substantially rigid on setting. This is shown at 1 in Figure 1 and 11 in Figures 2 4. The part 1 or 11 is then transferred immediately after moulding in a moulding machine to a second moulding station thereof or a pre-formed part 1 or 11 is placed in a mould in a moulding machine and the flexible wiper seal is then moulded from a synthetic plastics material, which will be flexible when set or cured, around the part 1 or 11. The flexible wiper seal is indicated by reference 2 in Figure 1 and by reference 12 in Figures 2 to 4.

In Figure 1, the flexible wiper seal 2 is moulded with a channel-shaped portion 3 extending circumferentially around the body part of the flap and with a peripheral wiper blade 4 integral with the channel-shaped part 3. To provide a retaining key between the body part 1 and the seal 2, the body part 1 may be moulded or drilled with holes spaced apart circumferentially around a marginal portion thereof into which holes the material of the seal 2 will enter and will set to form integral pins 5 within the holes in the body part.

In Figures 2 to 4, the body part 11 is formed with a flange 1 3 having circumferentially-spaced slots 14 therein, the flange 13 having in one face thereof circular lateral enlargements 1 5 of the slots 14. The flexible wiper seal 12 is moulded in the rebate formed by the flange 13 and the adjacent edge of the part 11 and has an integral radially-outwardly-extending peripheral portion 1 6. The material from which the wiper seal 12 is moulded enters and fills the slots 14 and sets therein to form a retaining key by means of the circular parts of the moulded seal 12 having filled the circular enlargements 1 5.

The method of manufacturing the flap as described with reference to Figure 1 or Figures 2-4 requires only two moulds or press tools and may be made in two moulding steps by employing a single moulding machine having two moulding stations in each of which a respective moulding step is performed or in two mouldings machines in each of which a respective moulding step is performed. As the manufacture of a mould or press tool is extremely expensive the manufacturing cost is much less than hitherto where similar flaps have been made by placing a flexible sheet between two separately moulded body layers. The manufacturing time according to the method of this invention is less as final assembly of pre-formed parts is not required.

Instead the flexible wiper seal is moulded directly onto the body part of the flap and is keyed thereto in one moulding operation.

The flap may be of shape other than circular or part-circular as viewed in elevation. It may, for example, be rectangular or square.

Although the invention is particularly concerned with the manufacture of an airobturating flap for use in a directional air nozzle or vent, the tubular deflector member itself may be formed with a moulded flap extending peripherally or part-peripherally around it to engage by a wiping action against the inside surface of a seating or housing in which the deflector member is mounted for swivelling, thereby to replace the sealing felt strip which is conventionally provided. The tubular deflector member or an outer wall or part thereof is moulded in one machine or in a first moulding station and then a peripheral or part-peripheral flexible wiper seal is moulded around the deflector member or part thereof in a second moulding machine or in a second moulding station. As before keying holes or slots may be provided in the deflector member or part thereof into which the material of the wiper seal will enter and set to provide a retaining key.

Instead of preforming the body parts 1 and 11 with holes or slots, they may instead be formed with integral projections around which the moulding material of the wiper seal will flow and set to provide a key.

Claims

1. A method of manufacturing a valve member comprising pre-forming a rigid or substantially rigid body part of the valve member and then moulding around the periphery or a portion of the periphery of said body part a flexible, peripherallyextending wiper seal which also extends outwardly from the periphery of said body part and which on setting or curing becomes attached to said body part of the valve member.

2. The method according to Claim 1 by which an aperture or a projection is formed in or on the pre-formed body part, wherebyithe moulding material from which the wiper'seal is formed will flow into said aperture or around said projection and on setting will form a key which will hold the wiper seal from separation from said body part.

3. The method according to Claim 2 in which the aperture or projection has an under-cut portion into or around which the moulding material from which the wiper seal is formed will flow and set, thereby to produce a key having å retaining portion located in the under-cut portion of said body part.

4. The method according to any preceding claim in which the moulding of the valve member is performed in a single moulding machine having two moulding stations in each of which a respective moulding step is performed.

5. The method according to any one of Claims 1-3 in which the moulding of the valve member is performed in two moulding machines in each of which a respective moulding step is performed.

6. A valve member comprising a substantially rigid body part and a flexible wiper seal which is moulded around the periphery or a portion of the periphery of said body part by a method according to any preceding claim.

7. A valve member as claimed in Claim 6 in which the body part has a slot pre-formed therein or a projection pre-formed thereon into or around which a portion moulded integrally with the wiper seal is moulded.

8. A valve member as claimed in Claim 7 and constructed substantially as described herein with reference to Figure 1 of the accompanying drawings.

9. A valve member as claimed in Claim 7 and constructed substantially as described herein with reference to Figures 2-4 of the accompanying drawings.