COMPRESSION SEALS

Abstract: A longitudinally extending sealing arrangement (30A) sealing between the edge (44) of a door opening in a motor vehicle body which is closable by a door (22), comprises a substantially rigid base part (34) from which outwardly extend two relatively rigid walls (32, 36). One of the walls (36) is connected to the base part (34) by means of a flexible hinge part (38). A wall portion (40), of high flexibility, connects the distal edges of the two walls (32, 36) together to define a hollow interior. The closing door (22) acts on the wall (36) which bends on its hinge (38) and provides a seal. The high flexibility of the flexible wall portion (40) assists the hinging of the rigid wall (36). The sealing arrangement is designed to provide a reactive force which is substantially constant with displacement, thus easing door closure.

Description: COMPRESSION SEALS The invention relates to a sealing arrangement for sealing around the edge of an opening closable by a closure member, comprising longitudinally extending mounting means adapted to be secured to the edge of the opening, a longitudinally extending sealing member, and connection means attaching the sealing member to the mounting means and allowing the sealing member to move relative to the mounting means when the sealing member is contacted by the closing closure member so as to provide a seal between the closure member and the edge of the opening. Such a sealing arrangement is shown in EP-A-0 178 064. In this sealing arrangement, movement of the sealing member in response to contact by the closing closure member is accommodated at least in part by flexing of resilient material. The more this resilient material flexes, in response to the contact, the greater is the reactive force produced by the material on the closing closure member. If the closure member is a door, such as in a motor vehicle for example, the increased reaction force can interfere with easy closing of the door. The invention aims to deal with this problem. According to the invention, therefore, the known sealing arrangement is characterised in that the sealing member is made of relatively hard plastics material and the connection means comprises a hinge whereby the reactive force exerted by the sealing member on the closing closure member is substantially constant as the closure member closes. Compression seals embodying the invention, and for use in sealing around doors and similar openings in motor vehicle bodies, will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which: Figure 1 is a perspective view of a known form of door seal; Figure 2 is a cross-section of the door seal of Figure 1, but showing it in operation; Figure 3 is a cross-sectional view corresponding to Figure 2 but showing one of the door seals embodying the invention; Figure 4 shows the seal of Figure 3 in operation; Figure 5 is a graph for explaining the operation of the door seal of Figures 3 and 4 ; Figure 6 is a cross-section through another of the door seals embodying the invention; Figure 7 shows the door seal of Figure 6 in operation; and Figure 8 is a cross-section through a further one of the door seals embodying the invention. The known door seal of Figure 1 comprises a channel-shaped gripping section 10 and a sealing section 12 which, in the form shown in Figure 1, is of hollow tubular form. The gripping section 10 comprises extruded flexible material 14, such as plastics or rubber material, in which is embedded a reinforcing metal carrier 16. The metal carrier 16 may be of any suitable form. For example, it may comprise U-shaped elements arranged together to form a channel extending along the gripping section and joined together by short flexible integral connecting links or perhaps disconnected from each other. Instead, the carrier could be made of channel-shaped metal with slits or slots formed through it to increase its flexibility. In another form, the carrier comprises wire looped to and fro along the length of the channel Other forms of carrier are possible. The carrier 16 can be incorporated into the extruded material 14 using a known co-extrusion process. As shown in Figure 1, the extruded material 14 provides integral gripping lips 18 which extend inwardly of the channel from the opposite inside side walls. The gripping lips 18 may be extruded to have the same or a different hardness from the channel-shaped material 14, t may be advantageous for the gripping lips 18 to be made of softer material . The sealing section 12 is in the form of a hollow tube made of soft flexible material, such as cellular or foamed rubber for example. It may be formed separately from the extruded material 14 and adhesively or otherwise secured to the gripping section afterwards Instead it may be co-extruded with the material 14. Figure 2 shows how the seal of Figure 1 is mounted to extend around a door opening m a motor vehicle body. The door opening is defined by a flange 20 where the inner and outer body panels of the vehicle come together at the door opening and are welded together. The flange 20 lies m the general plane of the opening and the gripping section 10 is mounted on it, as illustrated. The gripping lips 18 make frictional contact with the sides of the flange and firmly secure the gripping section 10 in position. In this way, the sealing section 12 is mounted to extend around the door opening on the outwardly directed face of the flange 20. Thus, when the door 22 closes, it compresses the sealing section 12 and forms a seal against air, dust, moisture and sound. The seal shown in Figure 3, and embodying the invention, has a gripping section 10 which may be of the same form as shown in Figures 1 and 2. The gripping section 10 in Figure 3 carries a sealing section 30. The sealing section 30 comprises a wall part 32 which is mounted on the outside face of one of the side walls of the gripping section 10 and which has a foot portion 34. A wall 36 of relatively rigid material is integrally connected to the foot 34 by means of a short section of flexible material 38. Finally, the distal end of the wall 36 is integrally connected to the corresponding end of the wall part 32 by a flexible wall portion 40. The wall part 32, the foot 34, the hinge 38, the wall 36 and the flexible wall portion 40 may be integrally extruded as a whole, using a suitable multiple extrusion process to ensure the correct hardness for each part. The sealing section may be extruded from any suitable material such as plastics or rubber material. Figure 4 shows the seal of Figure 3 in use, and corresponds to Figure 2. Thus, Figure 4 shows the seal mounted to run around the door opening and the closing door 22. As shown in Figure 4, the closing door contacts the wall 36 which thus hinges on the hinge 38, the flexible wall portion 40 bending accordingly. Curve A in Figure 5 shows the relationship between the reactive force applied by the wall 36 (Figures 3 and 4) to the closing door 22 and the displacement of the wall (and the door) . As shown, the reactive force is substantially constant over a wide range of displacement, after the initial contact shown at region A 1 . By way of comparison, curve B in Figure 5 shows the corresponding relationship between reactive force and displacement for a seal of the known type as shown in Figures 1 and 2. As illustrated, the reactive force continues to increase as the sealing section 12 is compressed, and then rises very rapidly over a region B 1 ; the region B 1 corresponds to the situation when the sealing section 12 has become substantially collapsed so that the opposite walls of the tube come into contact with each other. The curve A of Figure 5 shows that the seal 30 of Figures 3 and 4 is advantageous n that the reactive force produced by the sealing section is substantially constant. This ensures that the sealing section 30 produces a good sealing effect without producing a high resistance to closure of the door. The flexible wall portion 40 of the seal 30 produces substantially no resistance to the compression of the sealing section 30 and is primarily provided m order to close off the hollow interior. Figures 3 and 4 show only one of many forms which the sealing section 30 can take. Figure 6 shows a modified form 30A of the sealing section 30. Parts in Figure 6 corresponding to those in Figures 3 and 4 are correspondingly referenced. The sealing section 30A of Figure 6 is not mounted on a gripping section (such as the gripping section 10 of Figures 3 and 4) . Instead, the foot portion 34 is mounted in a channel 42 which is formed in the body panel 44 around the edge of the door opening. Figure 7 shows how the sealing section 30A reacts to the closing door 22. In the same manner as illustrated in Figure 4, the wall 36 hinges on the hinge 38, in response to the closing door, and the flexible wall portion 40 flexes accordingly. The wall 32 remains stationary (against the door frame) . The relationship between the reactive force produced by the sealing section 30A of Figures 6 and 7 and its displacement corresponds to that shown in curve A of Figure 5. Figure 8 shows another sealing section 30B embodying the invention. Again, parts corresponding to those in Figures 3 and 4 are similarly referenced. Sealing section 30B is in this case attached to the edge of the door 22. As shown, it is attached by means of fixtures (of which one, referenced 45, is illustrated) which fasten the foot 34 of the sealing section to one of the door panels 46. In the case of the sealing section 30B, there are two hinges, 38 and 38A. Hinge 38 hinges the wall 36 to the foot 34, and hinge 38A hinges the wall 32 to the foot. During initial mounting of the sealing section 30B, the wall 32 will hinge slightly on the hinge 38A, until arrested by the flange 50 at the edge of the door. Figure 8 shows the adjacent part of the door frame 48. When the closing door 22, carrying the sealing section 30B, moves towards the frame 38, wall 36 hinges on the hinge 38, in the manner already explained in connection with the other Figures. As before, the flexible wall 40 flexes to accommodate the hingeing of the wall 36. Again, the reactive force produced by the sealing section 30B follows the curve A shown in Figure 5.

Claims: £L M£ 1. A sealing arrangement for sealing around the edge (20) of an opening closable by a closure member (22) , comprising longitudinally extending mounting means (34) adapted to be secured to the edge (20) of the opening, a longitudinally extending sealing member (36) , and connection means (38) attaching the sealing member (36) to the mounting means (34) and allowing the sealing member (36) to move relative to the mounting means (34) when the sealing member (36) is contacted by the closing closure member (22) so as to provide a seal between the closure member (22) and the edge (20) of the opening, characterised in that the sealing member (36) is made of relatively hard plastics material and the connection means (38) comprises a hinge whereby the reactive force exerted by the sealing member (36) on the closing closure member (22) is substantially constant as the closure member (22) closes. 2. A sealing arrangement according to claim 1, characterised in that the sealing member (36) is part of the wall of a longitudinally extending hollow chamber (30) , the hinge (38) extending along a first one of the longitudinal edges of the sealing member (36) and the wall of the hollow chamber including a flexible wall portion (40) attached to the second one of the longitudinally extending edges of the sealing member (36) . 3. A sealing arrangement according to claim 2, characterised in that the wall of the hollow chamber (30) includes a substantially rigid wall member (32) attached to the mounting means (34) and spaced by the mounting means (34) from the sealing member (36) . 4. A sealing arrangement according to claim 3, characterised in that the relatively rigid wall member (32) is attached to the mounting member (34) by a further hinge (38A) . 5. A sealing arrangement according to claim 3 or 4, characterised in that the second longitudinally extending edge of the sealing member (36) is connected to a longitudinally extending edge of the relatively rigid wall member (32) by the flexible wall portion (40) . 6. A sealing arrangement according to any one of claims 2 to 5, characterised in that it is co-extruded as an integral whole. 7. A sealing arrangement according to any preceding claim, characterised by fixing means (10) for fixing the mounting member (34) to the edge (20) of the opening or to the closure member (22) . 8. A sealing arrangement according to claim 7, characterised in that the fixing means comprises a channel-shaped gripping member (10) to the outside wall of which is attached the mounting member (34) , and in that the gripping member (10) is adapted to embracingly grip a flange (20) which is on the edge of the opening or on the closure member (22) .

Inventors: SANS PHILIPPE, SANS, PHILIPPE
Applicants: DRAFTEX IND LTD, SANS PHILIPPE, DRAFTEX INDUSTRIES LIMITED, SANS, PHILIPPE
Application year: 1996
Main classification: B60J10
IPC codes: B60J10