GB1593727A

GB1593727A - Stationary seal

Info

Publication number: GB1593727A
Application number: GB1970778A
Authority: GB
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1977-07-12
Filing date: 1978-05-16
Publication date: 1981-07-22
Also published as: FR2397573A1; DE2731410A1; FR2397573B1

Description

(54) STATIONARY SEAL (71) We, ROBERT BOSCH GMBH, a German company of Postfach 50, 7 Stuttgart 1, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a stationary seal for making a sealed connection between two components. Although the invention is not so limited, a particular application of the invention is to effect a sealed connection between the cover and housing of a pump.

The invention is based on a seal of the type described in USA Patent Specification No.

3,285,615. This known seal is relatively expensive. Therefore, flat seals made from relatively hard material are widely used, although they generally have to be replaced by fresh seals after dismantling of the apparatus with which they are used for repairs to be effected.

Furthermore, their use frequently leads to distortion between the two components sealed together by the seal.

An object of the invention is to provide an improved seal. In accordance with the invention there is provided a fixed seal for making a sealed connection between two components, comprising a resilient seal member having a substantially rectangular cross-section located up rightly in a groove provided in one of the said two components such that it is positioned edge-wise in the groove, the thickness of the seal member at least over a greater proportion of its surface being less than the width of the groove, the seal member being stabilized against edge-wise tilting movement in the groove either by providing raised portions on one or both sides of the seal member at localized positions along its length or by providing lateral deviations of the groove at localized positions along its length.

The seal member can be re-used after it has been removed for the purpose of effecting repairs in the apparatus in which it is used. It always remains resilient and thus prevents distortion of the housing members. Moreover, the seal member can be manufactured in a simple manner in the form of a cut-off portion of a flexible tube.

In one advantageous construction the narrow side of the seal member projects somewhat from the reception groove where it is resiliently prestressed to abut against a contact surface of the other component.

Embodiments of the invention are hereinafter described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a first embodiment of the seal, Figure 2 is a plan view of a second embodiment of the seal, Figure 3 is a plan view of the seal member of Figure 2 by itself, and Figure 4 shows a portion of a flexible tube, partly in cross-section, for producing the seal member of Figure 3.

A seal 1 is provided for sealing the gap between two components, for example, between a housing (not shown) and a cover 4 which is mountable on the housing. The seal comprises a reception groove 2 in an end face 3 of the cover 4. The reception groove 2 forms a closed ring whose shape differs from that of a geometrical circle. The reception groove 2 is of uniform width along the whole of its length and has a plurality of localized lateral deviations 5 which form crests 6 and troughs 7 in the manner of corrugations.

An annular resilient seal member 8 having a flat, rectangular cross-section, is placed edgewise (i.e. uprightly) into the reception groove 2. The lateral deviations 5 forming the crests 6 and troughs 7 ensure that the seal member 8, placed on edge, does not tilt over when mounting the cover on the housing.

One narrow side of the seal member 8 projects somewhat beyond the surface of the end face 3 of the cover 4, so that the seal member is resiliently deformed slightly when the cover is bolted to the housing. Thus, the seal member 8 forms a reliable fixed seal between the housing and the cover.

In the described embodiment, the seal member 8 is produced by cutting annular portions from a smooth-wall flexible tube, the tube being cut in planes perpendicular to its axis.

Figure 2 shows a somewhat different seal 11. A reception groove 12 is provided in an end face 13 of a cover 14. The reception groove 12 also forms a closed ring whose shape is different from that of a circle. The reception groove 12 also has a uniform width throughout its length although it does not have any localized lateral deviations which fonn crests and troughs as in Figure 1.

An annular resilient seal member having a flat rectangular cross-section 15 is placed edgewise (i.e. uprightly) into the reception groove 12. However, the seal member 15 is provided on its outer and inner sides with a plurality of spaced, lateral thickened portions 16, 17, two thickened portions 16 and 17 being located opposite one another in each case. The crosssection of the seal member at the thickened portions 16, 17 has a width which is approximately equal to the width of the reception groove 12 and the portions 16, 17 thus ensure that the seal member 15, placed on edge, does not tilt over when mounting the cover on the housing. For this purpose, the thickened portions 16 and 17 are positioned preferably at the longer straight runs of the reception groove 12.Alternatively, it is possible to provide the thickened portions 16 and 17 so that they are not opposite each other but are located singly and alternate on the outside and inside of the seal member.

This seal member 15 also forms a reliable fixed seal between the housing and the cover.

Figure 3 shows that the thickened portions 16 and 17 of the seal member of Figure 2 are arranged into two groups 18 and 19 spaced apart at a distance which is greater than the distance between the individual thickened portions 16 or 17 of a respective group.

Figure 4 shows how the seal member 15 is produced by cutting an annular portion from a flexible tube 20, the flexible tube 20 having bead-like longitudinal ribs 21 and 22 on its outer and inner surfaces which form the thickened portions 16 and 17 of the seal member 15.

In modifications (not shown) the thickened portions 16 and 17 may not be opposite each other and the spacing between groups of thickened portions 16 may differ from that of groups of thickened portions 17; also, alternatively or additionally, the spacing between the individual portions 16 of a group may differ from that of the individual portions 17 of a group.

It is also conceivable to use a seal member which has thickened portions on only one side, either on the inside or the outside. The construction of the flexible tube would then be simpler.

Furthermore, it is obvious that it is just as possible to fit a seal member into the end face of a housing as it is to fit a seal member into a cover in the manner described.

Finally, it may be mentioned that, alternatively, the seal member may be in the form of a discontinuous strip instead of in the form of a closed annular seal member.

WHAT WE CLAIM IS: 1. A fixed seal for making a sealed connection between two components, comprising a resilient seal member having a substantially rectangular cross-section located uprightly in a groove provided in one of the said two components such that it is positioned edge-wise in the groove, the thickness of the seal member at least over a greater proportion of its surface being less than the width of the groove, the seal member being stabilized against edge-wise tilting movement in the groove either by pr viding raised portions on one or both sides of the seal member at localized positions along its length or by providing lateral deviations of the groove at localized positions along its length.

2. A seal, according to claim 1, in which the said raised portions comprise a plurality of spaced thickened portions of the seal member.

3. A seal, according to claim 1 or claim 2, in which the said portions are provided on one side only of the seal member.

4. A seal, according to claim 1 or claim 2, in which the said portions are provided on both sides of the seal member.

5. A seal, according to claim 4, in which the said portions are arranged in pairs, one portion of each pair on one side of the seal member being opposite the other portion of the pair on the other side of the seal member.

6. A seal, according to any preceding claim, in which the said portions or pairs of portions are arranged in groups.

7. A seal, according to claim 6, in which the spacing between the said portions and/or groups of said portions on one side of the seal member is/are different from the spacing between the said portions and/or groups of said portions on the other side of the seal member.

8. A seal, according to claim 1, in which the said lateral deviations form crest and troughs in the groove in the manner of corrugations.

9. A seal, according to claim 8, in which the projection of a tangential line across a crest is spaced from the opposite wall of the groove at a location adjacent the trough associated with the crest by a distance approximately equal to the thickness of the seal member.

10. A seal, according to any preceding claim, in which the seal member is annular and the groove forms a closed ring.

11. A seal, according to any preceding claim, in which the seal member has a width greater than the depth of the groove so that before assembly of the said two components an edge portion of the seal member extends out of the groove.

12. A seal, according to any preceding claim, in which the seal member is obtained by cutting a flexible tube of seal material in a plane perpendicular to the tube axis.

13. A seal, according to claim 12, in which the flexible tube has longitudinal ribs on its

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. face 13 of a cover 14. The reception groove 12 also forms a closed ring whose shape is different from that of a circle. The reception groove 12 also has a uniform width throughout its length although it does not have any localized lateral deviations which fonn crests and troughs as in Figure 1. An annular resilient seal member having a flat rectangular cross-section 15 is placed edgewise (i.e. uprightly) into the reception groove 12. However, the seal member 15 is provided on its outer and inner sides with a plurality of spaced, lateral thickened portions 16, 17, two thickened portions 16 and 17 being located opposite one another in each case. The crosssection of the seal member at the thickened portions 16, 17 has a width which is approximately equal to the width of the reception groove 12 and the portions 16, 17 thus ensure that the seal member 15, placed on edge, does not tilt over when mounting the cover on the housing. For this purpose, the thickened portions 16 and 17 are positioned preferably at the longer straight runs of the reception groove 12.Alternatively, it is possible to provide the thickened portions 16 and 17 so that they are not opposite each other but are located singly and alternate on the outside and inside of the seal member. This seal member 15 also forms a reliable fixed seal between the housing and the cover. Figure 3 shows that the thickened portions 16 and 17 of the seal member of Figure 2 are arranged into two groups 18 and 19 spaced apart at a distance which is greater than the distance between the individual thickened portions 16 or 17 of a respective group. Figure 4 shows how the seal member 15 is produced by cutting an annular portion from a flexible tube 20, the flexible tube 20 having bead-like longitudinal ribs 21 and 22 on its outer and inner surfaces which form the thickened portions 16 and 17 of the seal member 15. In modifications (not shown) the thickened portions 16 and 17 may not be opposite each other and the spacing between groups of thickened portions 16 may differ from that of groups of thickened portions 17; also, alternatively or additionally, the spacing between the individual portions 16 of a group may differ from that of the individual portions 17 of a group. It is also conceivable to use a seal member which has thickened portions on only one side, either on the inside or the outside. The construction of the flexible tube would then be simpler. Furthermore, it is obvious that it is just as possible to fit a seal member into the end face of a housing as it is to fit a seal member into a cover in the manner described. Finally, it may be mentioned that, alternatively, the seal member may be in the form of a discontinuous strip instead of in the form of a closed annular seal member. WHAT WE CLAIM IS:

1. A fixed seal for making a sealed connection between two components, comprising a resilient seal member having a substantially rectangular cross-section located uprightly in a groove provided in one of the said two components such that it is positioned edge-wise in the groove, the thickness of the seal member at least over a greater proportion of its surface being less than the width of the groove, the seal member being stabilized against edge-wise tilting movement in the groove either by pr viding raised portions on one or both sides of the seal member at localized positions along its length or by providing lateral deviations of the groove at localized positions along its length.

inner and/or outer surface forming the said portions.

14. A seal, according to any preceding claim, in which the said one of the two components comprises the cover or the housing of a pump.

15. A seal, according to any preceding claim, in which the groove has a substantially rectangular cross-section and has a uniform width along its length.

16. A fixed seal substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

17. A pump including a seal according to any preceding claim.