GB2455320A - A sealing means including a carrier part and a sealing element - Google Patents

Abstract

A sealing means 10 comprises: a rigid carrier part 11 which may be formed from fibre-reinforced plastic ; a sealing element 12 which may be formed from an elastomer; and fixing means 13, the sealing element 12 being adapted to form a seal against another structure. The fixing means 13 is adapted to mechanically engage with the sealing element 12 to secure the sealing element 12 to the carrier part 11. The fixing means 13 may take to form of a series of radially inwardly extending pins.

Description

SEALING MEANS

This invention relates to a sealing means and, in particular, relates to a mechanically bonded sealing means.

Known seals comprise a metal carrier ring to which is secured, by adhesive, a resilient sealing element. The resilient sealing portion is usually of rubber or plastics depending upon the intended application of the sealing means. The adhesive is applied during moulding and vulcanisation of the resilient sealing element. The adhesive fastens the sealing element to the carrier ring. In use, the sealing means is placed between two surfaces that are adapted to be secured and sealed together.

The two surfaces are brought together into engagement with the sealing element, which seals the gap between the surfaces. The surfaces can then be tightened together by appropriate means into engagement with the metal carrier ring. Thus, the carrier ring provides a stop to tighten the surfaces up to, while ensuring that the sealing element is not over compressed.

According to a first aspect of the present invention, we provide a sealing means comprising a carrier part and a sealing element, the sealing element being adapted to form a seal against another structure, the carrier part including fixing means adapted to mechanically engage with the sealing element to secure the sealing element to the carrier part.

This is advantageous as the fixing means provides the means to join the sealing element and carrier part together without adhesive. Thus, the sealing element is secured to the carrier part only by the mechanical engagement therebetween in a type of interference fit. The sealing means is less complex to manufacture as no adhesives are used. Adhesives contain volatile chemicals and therefore the seal of the invention is advantageous as it is less damaging to the environment. Further, when the sealing means is recycled, the carrier part and the sealing element can be separated and processed accordingly without the need for a chemical based recycling process to deal with adhesive, which would render the sealing element unsuitable for reprocessing.

Preferably, the carrier part is of plastics and in particular of reinforced plastics. This enables the carrier part to be moulded integrally with the fixing means. This is advantageous as manufacturing cost is low. It is particularly advantageous over a carrier part of metal, with which it would be necessary to plate and then drill, stamp or machine the fixing means. Preferably the sealing element is of an elastomer. The resulting sealing means is typically of low weight, is corrosion resistant and of flash free detail.

Preferably, the fixing means extends within the sealing element. Thus, the fixing means may comprise at least one fixing projection that extends from the carrier part into the sealing element such that the sealing element surrounds the fixing means. Preferably, the fixing means has a proximal end that contacts the carrier part and a free end, the fixing means being constructed and arranged such that a recess is formed between the carrier part and the free end of the fixing means. Preferably, the sealing element is adapted to extend with this recess. This is advantageous as the sealing element is held in engagement with the fixing means by friction and the resilience of the sealing element material. In particular, friction exists between the fixing means and sealing element that acts to prevent the two parts separating. Also, as the sealing element surrounds the fixing means, the resilience of the sealing element material acts to grip the fixing means and prevent it expanding out of the recess.

Preferably, the fixing means tapers from the free end to the proximal end to form the recess. Preferably the fixing means has a cut- out therein that forms the recess. This structure is advantageous as the sealing portion is adapted to be received within the recess to assist in retaining the carrier part and sealing element together.

Preferably the fixing means comprises a plurality of fixing pins that extend from the carrier part, the fixing pins having recesses formed therein. Preferably the fixing pins are thicker in an axial direction at their free ends than at their proximal ends. Preferably the fixing pins are equally angularly spaced around the carrier part. Preferably the fixing pins have gaps therebetween and that the gaps are narrower adjacent the free ends of each of the fixing pins than they are adjacent the proximal ends of the fixing pins. Most preferably, at least one of the tangentially facing sides of each of the fixing pins includes an undercut that extends between the free end of the at least one fixing pin and the carrier part.

Preferably both tangentially facing sides of each of the fixing pins include an undercut. Thus, the undercuts add to the recess formed by the taper in the axial thickness of the fixing pins to securely mechanically hold the sealing element and carrier part together.

The fixing means may have slots or holes formed therein. The slots and/or holes are adapted to receive a proportion of the sealing element to improve its mechanical interengagement with the fixing means.

Preferably the sealing element includes a primary sealing portion that extends longitudinally to a first height above the carrier part and a secondary sealing portion that extend longitudinally to a second height above the carrier part. Preferably, the first height is greater than the second height. Preferably the secondary sealing portion is radially aligned with the fixing means.

Preferably the carrier part is ring shaped. The fixing means may extend radially inwardly from an inwardly facing surface of the carrier ring.

Alternatively the fixing means may extend radially outwardly from an outwardly facing surface of the carrier ring. Alternatively, the carrier part may have a profiled shape to Suit bespoke applications.

According to a second aspect of the invention we provide a method for forming the sealing means of the first aspect of the invention, the sealing means comprising a carrier part having fixing means and a sealing element, the method comprising the steps of; placing the carrier part in a mould; and flowing a resilient material around at least the fixing means to form the sealing element.

This method of forming the sealing means is advantageous as the sealing element forms a mechanical interengagement with the fixing means to secure the carrier part and sealing element together. Thus, adhesives are not required as the sealing element forms a mechanical interengagement with the fixing means that can be further secured by cross-linking of the sealing element when it cures around fixing means.

Preferably the method includes the step of compressing the sealing element around at least the fixing means.

Preferably, the carrier part includes upstanding ribs adjacent the fixing means for providing a barrier to the flowing resilient material and wherein during the step of compressing the sealing element around the fixing part, the ribs are crushed to be substantially flush with the remainder of the carrier part.

Preferably the fixing means comprises at least one fixing projection.

The sealing means may be a ring seal for sealing against water, gases, oils, shielding, non magnetic environments plus a wide range of other fluids across existing and new technology environments where an effective leak-proof seal is required between two mating faces.

There now follows by way of example only a detailed description of the present invention with reference to the accompanying drawings in which; Figure 1 shows a sectional side view of a known seal; Figure 2 shows a sectional plan view of an embodiment of a sealing means of the invention; Figure 3 shows a plan view of the carrier part shown in Figure 2; Figure 4 shows a sectional side view along the line A-A in Figure 2; Figure 5 shows a sectional plan view of a second embodiment of a sealing means of the invention; Figure 6 shows a sectional side view along the line B-B shown in Figure 5; Figure 7 shows a sectional plan view of a third embodiment of a sealing means of the invention; and Figure 8 shows a sectional side view along the line C-C shown in Figure 7.

Sealing means' are used in junctions between abutting surfaces to prevent substances leaving or entering through the junction. Thus, they may prevent contamination or leakage or retain pressure. The seals discussed below are ring seals, generally comprising a carrier part and a sealing element. However, it will be appreciated that the invention may be applied to other forms of sealing means.

Figure 1 shows a sealing means 1 of the prior art that comprises a carrier part 2 of metal and a sealing element 3 of elastomer. The carrier part 2 and sealing element 3 are ring shaped. The inside diameter of the carrier part 2 is substantially equal to the outside diameter of the sealing element 3 such that the sealing element fits concentrically within and abuts the carrier part 2. The carrier part 2 and sealing element 3 are affixed together at their junction by a chemical adhesive. Thus, during manufacture, the carrier part 2 is coated in adhesive as required and the sealing element 3 is joined to it.

Figure 2 shows a first embodiment of a sealing means of the invention.

The sealing means 10 comprises a carrier part 11, a sealing element 12 and fixing means 13. The carrier part 11 comprises a ring shaped element having the sealing element 12 attached to an inwardly facing surface 14. The sealing element 12 comprises an annular sealing element body 15 and a sealing element lip 16. The sealing element body 15 has a substantially trapezoidal cross-section while the sealing element lip 16 is also trapezoidal in cross-section but the sides diverge to a greater degree.

In particular, the sealing lip 16 includes primary sealing portions 24 that have a greater inclination to the radial direction than secondary sealing portions 24' formed on the sealing element body 15. The sealing means therefore has primary and secondary annular sealing portions 24 and 24' that project longitudinally outwardly.

The carrier part 11 is of plastics and the sealing element 12 is of elastomer. If required, the carrier part 11 can be reinforced with 20%, 30% or 50% glass as necessary.

As can be seen more clearly in Figure 3, the fixing means 13 comprises eight "dovetailed" pins equally spaced around the inwardly facing surface 14. Gaps 21 are formed between the pins 13. The pins have a proximal end face 17 and a free end face 18. The proximal end face 17 joins the carrier ring 11, while the free end face 18 projects radially inwardly. The proximal end face 17 and the free end face 18 have a curvature that is concentric with the carrier ring 11. Each of the pins 13 has a first side 19a that substantially faces one tangential direction and a second side 19b that substantially faces the other tangential direction.

The first and second sides 19a, 19b of each of the fixing pins 13 taper from the free end 18 to the proximal end 17 such that an undercut 20 is created between each of the free ends 18 and the carrier ring 11. In particular, the arcuate surface at the free end 18 of each fixing pin 13 has a greater angular width than at least part of the remainder of the fixing pin 13. Thus, in this embodiment an angular width 25, measured from the centre of the carrier ring, of the arcuate surface at the free end 18 is greater than an angular width 26 of an arc that extends between the first and second sides 19a, 19b through the fixing pin 13 at a point between the free end 18 and proximal end 17. As the sealing element 12 extends into the gaps 21 and the re-entrant undercuts 20, it cannot be easily separated from the carrier part 11.

The left-hand side of Figure 4 shows a section through a pin of the fixing means 13. The right-hand side shows a section through the carrier ring 11 in the gap 21 between two pins of the fixing means 13, although one of the pins is shown in dashed lines. Each of the pins 13 have a third side 22a that substantially faces one radial direction and a fourth side 22b that substantially faces an opposite radial direction. The third and fourth sides 22a, 22b also taper from the free end 18 to the proximal end 17 thereby creating a further undercut 23 between each of the free ends 18 and the carrier ring 11. Thus, each fixing pin 13 decreases thickness from the free end 18 to the proximal end 17, the thickness being the dimension of the pin 13 in the axial direction of the securing ring 11.

The undercuts 20 and the undercuts 23 form a recess to receive the sealing element 12 and thereby securely retain the sealing element 12 to the carrier part 11 without the need for adhesive. The sealing element 12 is held securely as it extends into the recess formed by the undercuts 20 and 23 and into the gaps 21 between the pins 13. Thus, the sealing element 12 is prevented from being separated from the carrier part 11 due to the shape of the fixing means 13 and the portions of the sealing element body 15 that extend behind the free end faces 18. It has been surprisingly found that this mechanical interengagement between the carrier part 11 and sealing element 12 is sufficient to securely hold the parts 11 and 12 together under their typical operating conditions at least

as well as the adhesive used in prior art designs.

In use, the sealing means 10 is placed between two surfaces of another structure. As surfaces are brought together the primary sealing portions 24 will contact the surfaces and the sealing element 12 will be the first to be compressed. Further the secondary sealing portions 24' will be compressed. The compression of the secondary sealing portions 24' causes the sealing element 12 to compress around the fixing means 13 to hold the sealing means 10 together. The secondary sealing portions 24' also act to provide an effective seal from pressure from the outside diameter and inside diameter of the sealing element as would be required in a differential sealing arrangement. The two surfaces can then be tightened together up to the carrier part 11. When tightened up to the carrier part 11, the sealing element 12 is deformed such that the sealing portions 24 lie flush with the sealing element body 15 and form the seal between the surfaces.

It will be appreciated that although the secondary sealing portions 24' are shown as inclined surfaces formed in the sealing element body 15, they may comprise an annular rib that extends around a sealing element body 15 of substantially rectangular cross-section. Further, secondary sealing portions 24' may comprise the annular rib in addition to the inclined surfaces shown in the embodiment.

Figure 5 discloses a second embodiment of the invention and the same reference numerals have been used for corresponding parts. In general, the sealing means 30 comprises a carrier part 11, a sealing element 12 and a fixing means 31. In this embodiment, the fixing means 31 comprises a single annular projection that extends radially inwardly from the radially inwardly facing surface 14 of the carrier part 11.

The fixing projection 31 has two sides 22a and 22b that correspond to the third side and fourth side in the previous embodiment. As before, the sides 22a, 22b taper from the free end 18 to the proximal end 17 thereby creating the undercut 23 between the free end 18 and the carrier ring 11.

The fixing projection 31 has a plurality of arcuate slots 32 that extend through the fixing projection 31 in an axial direction. This embodiment has eight slots 32 that are equally angularly spaced around the fixing means 31. The slots 32 form a recess into which the sealing element extends as shown on the right hand side of Figure 6. Although eight slots are shown, it will be appreciated that there may be one, two, three, four, five, six, seven, ten, twelve, fourteen or more slots.

Thus, in the second embodiment, the undercut 23 and the slots 32 form the recess into which the sealing element 12 extends. Thus, the sealing element 12 is securely joined to the carrier part 11 due to the shape of the fixing means 13 and the portions of the sealing element 12 that extend behind the free end faces 18 into undercuts 23 and slots 32.

A third embodiment of a sealing means 40 is shown in Figures 7 and 8.

This embodiment is substantially similar to the second embodiment and the same reference numerals have been used for corresponding parts. In this embodiment the slots 32 are replaced with holes 41. There are eight holes 41 that are equally angularly spaced around the fixing means 31.

The holes 32 comprise circular bores that extend through the fixing means 15 in an axial direction. The holes 41 form a recess in the fixing means. As can be seen from the right hand side of Figure 8, the sealing element 12 is adapted to extend with the holes 41. Although eight holes are shown, it will be appreciated that there may be one, two, three, four, five, six, seven, ten, twelve, fourteen or more holes.

Thus, in this third embodiment, a recess is formed by the combination of the undercut 23 and the holes 41. The sealing element 12 is held securely to the carrier part 11 as it extends into this recess.

It will be appreciated that the sealing element may be adapted to be secured to the radially outwardly facing surface of the carrier ring. Thus, the fixing means would therefore extend radially outwardly to allow the sealing element to be secured thereto. SEALING MEANS

This invention relates to a sealing means and, in particular, relates to a mechanically bonded sealing means.

Known seals comprise a metal carrier ring to which is secured, by adhesive, a resilient sealing element. The resilient sealing portion is usually of rubber or plastics depending upon the intended application of the sealing means. The adhesive is applied during moulding and vulcanisation of the resilient sealing element. The adhesive fastens the sealing element to the carrier ring. In use, the sealing means is placed between two surfaces that are adapted to be secured and sealed together.

The two surfaces are brought together into engagement with the sealing element, which seals the gap between the surfaces. The surfaces can then be tightened together by appropriate means into engagement with the metal carrier ring. Thus, the carrier ring provides a stop to tighten the surfaces up to, while ensuring that the sealing element is not over compressed.

According to a first aspect of the present invention, we provide a sealing means comprising a carrier part and a sealing element, the sealing element being adapted to form a seal against another structure, the carrier part including fixing means adapted to mechanically engage with the sealing element to secure the sealing element to the carrier part.

This is advantageous as the fixing means provides the means to join the sealing element and carrier part together without adhesive. Thus, the sealing element is secured to the carrier part only by the mechanical engagement therebetween in a type of interference fit. The sealing means is less complex to manufacture as no adhesives are used. Adhesives contain volatile chemicals and therefore the seal of the invention is advantageous as it is less damaging to the environment. Further, when the sealing means is recycled, the carrier part and the sealing element can be separated and processed accordingly without the need for a chemical based recycling process to deal with adhesive, which would render the sealing element unsuitable for reprocessing.

Preferably, the carrier part is of plastics and in particular of reinforced plastics. This enables the carrier part to be moulded integrally with the fixing means. This is advantageous as manufacturing cost is low. It is particularly advantageous over a carrier part of metal, with which it would be necessary to plate and then drill, stamp or machine the fixing means. Preferably the sealing element is of an elastomer. The resulting sealing means is typically of low weight, is corrosion resistant and of flash free detail.

Preferably, the fixing means extends within the sealing element. Thus, the fixing means may comprise at least one fixing projection that extends from the carrier part into the sealing element such that the sealing element surrounds the fixing means. Preferably, the fixing means has a proximal end that contacts the carrier part and a free end, the fixing means being constructed and arranged such that a recess is formed between the carrier part and the free end of the fixing means. Preferably, the sealing element is adapted to extend with this recess. This is advantageous as the sealing element is held in engagement with the fixing means by friction and the resilience of the sealing element material. In particular, friction exists between the fixing means and sealing element that acts to prevent the two parts separating. Also, as the sealing element surrounds the fixing means, the resilience of the sealing element material acts to grip the fixing means and prevent it expanding out of the recess.

Preferably, the fixing means tapers from the free end to the proximal end to form the recess. Preferably the fixing means has a cut- out therein that forms the recess. This structure is advantageous as the sealing portion is adapted to be received within the recess to assist in retaining the carrier part and sealing element together.

Preferably the fixing means comprises a plurality of fixing pins that extend from the carrier part, the fixing pins having recesses formed therein. Preferably the fixing pins are thicker in an axial direction at their free ends than at their proximal ends. Preferably the fixing pins are equally angularly spaced around the carrier part. Preferably the fixing pins have gaps therebetween and that the gaps are narrower adjacent the free ends of each of the fixing pins than they are adjacent the proximal ends of the fixing pins. Most preferably, at least one of the tangentially facing sides of each of the fixing pins includes an undercut that extends between the free end of the at least one fixing pin and the carrier part.

Preferably both tangentially facing sides of each of the fixing pins include an undercut. Thus, the undercuts add to the recess formed by the taper in the axial thickness of the fixing pins to securely mechanically hold the sealing element and carrier part together.

The fixing means may have slots or holes formed therein. The slots and/or holes are adapted to receive a proportion of the sealing element to improve its mechanical interengagement with the fixing means.

Preferably the sealing element includes a primary sealing portion that extends longitudinally to a first height above the carrier part and a secondary sealing portion that extend longitudinally to a second height above the carrier part. Preferably, the first height is greater than the second height. Preferably the secondary sealing portion is radially aligned with the fixing means.

Preferably the carrier part is ring shaped. The fixing means may extend radially inwardly from an inwardly facing surface of the carrier ring.

Alternatively the fixing means may extend radially outwardly from an outwardly facing surface of the carrier ring. Alternatively, the carrier part may have a profiled shape to Suit bespoke applications.

According to a second aspect of the invention we provide a method for forming the sealing means of the first aspect of the invention, the sealing means comprising a carrier part having fixing means and a sealing element, the method comprising the steps of; placing the carrier part in a mould; and flowing a resilient material around at least the fixing means to form the sealing element.

This method of forming the sealing means is advantageous as the sealing element forms a mechanical interengagement with the fixing means to secure the carrier part and sealing element together. Thus, adhesives are not required as the sealing element forms a mechanical interengagement with the fixing means that can be further secured by cross-linking of the sealing element when it cures around fixing means.

Preferably the method includes the step of compressing the sealing element around at least the fixing means.

Preferably, the carrier part includes upstanding ribs adjacent the fixing means for providing a barrier to the flowing resilient material and wherein during the step of compressing the sealing element around the fixing part, the ribs are crushed to be substantially flush with the remainder of the carrier part.

Preferably the fixing means comprises at least one fixing projection.

The sealing means may be a ring seal for sealing against water, gases, oils, shielding, non magnetic environments plus a wide range of other fluids across existing and new technology environments where an effective leak-proof seal is required between two mating faces.

There now follows by way of example only a detailed description of the present invention with reference to the accompanying drawings in which; Figure 1 shows a sectional side view of a known seal; Figure 2 shows a sectional plan view of an embodiment of a sealing means of the invention; Figure 3 shows a plan view of the carrier part shown in Figure 2; Figure 4 shows a sectional side view along the line A-A in Figure 2; Figure 5 shows a sectional plan view of a second embodiment of a sealing means of the invention; Figure 6 shows a sectional side view along the line B-B shown in Figure 5; Figure 7 shows a sectional plan view of a third embodiment of a sealing means of the invention; and Figure 8 shows a sectional side view along the line C-C shown in Figure 7.

Sealing means' are used in junctions between abutting surfaces to prevent substances leaving or entering through the junction. Thus, they may prevent contamination or leakage or retain pressure. The seals discussed below are ring seals, generally comprising a carrier part and a sealing element. However, it will be appreciated that the invention may be applied to other forms of sealing means.

Figure 1 shows a sealing means 1 of the prior art that comprises a carrier part 2 of metal and a sealing element 3 of elastomer. The carrier part 2 and sealing element 3 are ring shaped. The inside diameter of the carrier part 2 is substantially equal to the outside diameter of the sealing element 3 such that the sealing element fits concentrically within and abuts the carrier part 2. The carrier part 2 and sealing element 3 are affixed together at their junction by a chemical adhesive. Thus, during manufacture, the carrier part 2 is coated in adhesive as required and the sealing element 3 is joined to it.

Figure 2 shows a first embodiment of a sealing means of the invention.

The sealing means 10 comprises a carrier part 11, a sealing element 12 and fixing means 13. The carrier part 11 comprises a ring shaped element having the sealing element 12 attached to an inwardly facing surface 14. The sealing element 12 comprises an annular sealing element body 15 and a sealing element lip 16. The sealing element body 15 has a substantially trapezoidal cross-section while the sealing element lip 16 is also trapezoidal in cross-section but the sides diverge to a greater degree.

In particular, the sealing lip 16 includes primary sealing portions 24 that have a greater inclination to the radial direction than secondary sealing portions 24' formed on the sealing element body 15. The sealing means therefore has primary and secondary annular sealing portions 24 and 24' that project longitudinally outwardly.

The carrier part 11 is of plastics and the sealing element 12 is of elastomer. If required, the carrier part 11 can be reinforced with 20%, 30% or 50% glass as necessary.

As can be seen more clearly in Figure 3, the fixing means 13 comprises eight "dovetailed" pins equally spaced around the inwardly facing surface 14. Gaps 21 are formed between the pins 13. The pins have a proximal end face 17 and a free end face 18. The proximal end face 17 joins the carrier ring 11, while the free end face 18 projects radially inwardly. The proximal end face 17 and the free end face 18 have a curvature that is concentric with the carrier ring 11. Each of the pins 13 has a first side 19a that substantially faces one tangential direction and a second side 19b that substantially faces the other tangential direction.

The first and second sides 19a, 19b of each of the fixing pins 13 taper from the free end 18 to the proximal end 17 such that an undercut 20 is created between each of the free ends 18 and the carrier ring 11. In particular, the arcuate surface at the free end 18 of each fixing pin 13 has a greater angular width than at least part of the remainder of the fixing pin 13. Thus, in this embodiment an angular width 25, measured from the centre of the carrier ring, of the arcuate surface at the free end 18 is greater than an angular width 26 of an arc that extends between the first and second sides 19a, 19b through the fixing pin 13 at a point between the free end 18 and proximal end 17. As the sealing element 12 extends into the gaps 21 and the re-entrant undercuts 20, it cannot be easily separated from the carrier part 11.

The left-hand side of Figure 4 shows a section through a pin of the fixing means 13. The right-hand side shows a section through the carrier ring 11 in the gap 21 between two pins of the fixing means 13, although one of the pins is shown in dashed lines. Each of the pins 13 have a third side 22a that substantially faces one radial direction and a fourth side 22b that substantially faces an opposite radial direction. The third and fourth sides 22a, 22b also taper from the free end 18 to the proximal end 17 thereby creating a further undercut 23 between each of the free ends 18 and the carrier ring 11. Thus, each fixing pin 13 decreases thickness from the free end 18 to the proximal end 17, the thickness being the dimension of the pin 13 in the axial direction of the securing ring 11.

The undercuts 20 and the undercuts 23 form a recess to receive the sealing element 12 and thereby securely retain the sealing element 12 to the carrier part 11 without the need for adhesive. The sealing element 12 is held securely as it extends into the recess formed by the undercuts 20 and 23 and into the gaps 21 between the pins 13. Thus, the sealing element 12 is prevented from being separated from the carrier part 11 due to the shape of the fixing means 13 and the portions of the sealing element body 15 that extend behind the free end faces 18. It has been surprisingly found that this mechanical interengagement between the carrier part 11 and sealing element 12 is sufficient to securely hold the parts 11 and 12 together under their typical operating conditions at least

as well as the adhesive used in prior art designs.

In use, the sealing means 10 is placed between two surfaces of another structure. As surfaces are brought together the primary sealing portions 24 will contact the surfaces and the sealing element 12 will be the first to be compressed. Further the secondary sealing portions 24' will be compressed. The compression of the secondary sealing portions 24' causes the sealing element 12 to compress around the fixing means 13 to hold the sealing means 10 together. The secondary sealing portions 24' also act to provide an effective seal from pressure from the outside diameter and inside diameter of the sealing element as would be required in a differential sealing arrangement. The two surfaces can then be tightened together up to the carrier part 11. When tightened up to the carrier part 11, the sealing element 12 is deformed such that the sealing portions 24 lie flush with the sealing element body 15 and form the seal between the surfaces.

It will be appreciated that although the secondary sealing portions 24' are shown as inclined surfaces formed in the sealing element body 15, they may comprise an annular rib that extends around a sealing element body 15 of substantially rectangular cross-section. Further, secondary sealing portions 24' may comprise the annular rib in addition to the inclined surfaces shown in the embodiment.

Figure 5 discloses a second embodiment of the invention and the same reference numerals have been used for corresponding parts. In general, the sealing means 30 comprises a carrier part 11, a sealing element 12 and a fixing means 31. In this embodiment, the fixing means 31 comprises a single annular projection that extends radially inwardly from the radially inwardly facing surface 14 of the carrier part 11.

The fixing projection 31 has two sides 22a and 22b that correspond to the third side and fourth side in the previous embodiment. As before, the sides 22a, 22b taper from the free end 18 to the proximal end 17 thereby creating the undercut 23 between the free end 18 and the carrier ring 11.

The fixing projection 31 has a plurality of arcuate slots 32 that extend through the fixing projection 31 in an axial direction. This embodiment has eight slots 32 that are equally angularly spaced around the fixing means 31. The slots 32 form a recess into which the sealing element extends as shown on the right hand side of Figure 6. Although eight slots are shown, it will be appreciated that there may be one, two, three, four, five, six, seven, ten, twelve, fourteen or more slots.

Thus, in the second embodiment, the undercut 23 and the slots 32 form the recess into which the sealing element 12 extends. Thus, the sealing element 12 is securely joined to the carrier part 11 due to the shape of the fixing means 13 and the portions of the sealing element 12 that extend behind the free end faces 18 into undercuts 23 and slots 32.

A third embodiment of a sealing means 40 is shown in Figures 7 and 8.

This embodiment is substantially similar to the second embodiment and the same reference numerals have been used for corresponding parts. In this embodiment the slots 32 are replaced with holes 41. There are eight holes 41 that are equally angularly spaced around the fixing means 31.

The holes 32 comprise circular bores that extend through the fixing means 15 in an axial direction. The holes 41 form a recess in the fixing means. As can be seen from the right hand side of Figure 8, the sealing element 12 is adapted to extend with the holes 41. Although eight holes are shown, it will be appreciated that there may be one, two, three, four, five, six, seven, ten, twelve, fourteen or more holes.

Thus, in this third embodiment, a recess is formed by the combination of the undercut 23 and the holes 41. The sealing element 12 is held securely to the carrier part 11 as it extends into this recess.

It will be appreciated that the sealing element may be adapted to be secured to the radially outwardly facing surface of the carrier ring. Thus, the fixing means would therefore extend radially outwardly to allow the sealing element to be secured thereto.

Claims (25)

1. A sealing means comprising a carrier part and a sealing element, the sealing element being adapted to form a seal against another structure, the carrier part including fixing means adapted to mechanically engage with the sealing element to secure the sealing element to the carrier part.

2. The sealing means of claim 1, in which the sealing element is secured to the carrier part only by the mechanical engagement therebetween.

3. The sealing means of claim 1, in which the carrier part is of plastics and in particular of reinforced plastics.

4. The sealing means of any preceding claim, in which the sealing element is of an elastomer.

5. The sealing means of any preceding claim, in which the fixing means extends within the sealing element.

6. The sealing means of claim 5, in which the fixing means comprises at least one fixing projection that extends from the carrier part into the sealing element such that the sealing element surrounds the fixing means.

7. The sealing means of any preceding claim, in which the fixing means has a proximal end that contacts the carrier part and a free end, S...

the fixing means being constructed and arranged such that a recess is 30 formed between the carrier part and the free end of the fixing means.

S. ***. * * * .* * . * S **

8. The sealing means of claim 7, in which the sealing element is adapted to extend within the recess.

9. The sealing means of claim 7, in which the fixing means tapers from the free end to the proximal end to form the recess.

10. The sealing means of claim 7, in which the fixing means has a cut-out therein that forms the recess.

11. The sealing means of any preceding claim, in which the fixing means comprises a plurality of fixing pins that extend from the carrier part, the fixing pins having recesses formed therein.

12. The sealing means of claim 11, in which the fixing pins are thicker in an axial direction at their free ends than at their proximal ends.

13. The sealing means of claim 11 or claim 12, in which the fixing pins are equally angularly spaced around the carrier part.

14. The sealing means of any of claims 11 to 13, in which the fixing pins have gaps therebetween and that the gaps are narrower adjacent the free ends of each of the fixing pins than they are adjacent the proximal ends of the fixing pins.

15. The sealing means of any of claims 11 to 14, in which, at least one of the tangentially facing sides of each of the fixing pins includes an **. undercut that extends between the free end of the at least one fixing pin and the carrier part. I... * .

16. The sealing means of any of claims 11 to 15. in which both * *I** * tangentially facing sides of each of the fixing pins include an undercut. * ** * * * * **

Thus, the undercuts add to the recess formed by the taper in the axial thickness of the fixing pins to securely mechanically hold the sealing element and carrier part together.

17. The sealing means of any preceding claim, in which the fixing means has slots or holes formed therein.

18. The sealing means of any preceding claim, in which the sealing element includes a primary sealing portion that extends longitudinally to a first height above the carrier part and a secondary sealing portion that extend longitudinally to a second height above the carrier part.

19. The sealing means of claim 18, in which the first height is greater than the second height.

20. The sealing means of claim 18 or claim 19, in which the secondary sealing portion is radially aligned with the fixing means.

21. The sealing means of any preceding claim, in which the carrier part is ring shaped.

22. A method for forming the sealing means of any preceding claim, the sealing means comprising a carrier part having fixing means and a sealing element, the method comprising the steps of; placing the carrier part in a mould; and flowing a resilient material around at least the fixing means to form the sealing element. * * **.*

*.

23. A method according to claim 22, in which the method includes the * 30 step of compressing the sealing element around at least the fixing S.....

* . means. * . . S *S

24. A method according to claim 22, in which the carrier part includes upstanding ribs adjacent the fixing means for providing a barrier to the flowing resilient material and wherein during the step of compressing the sealing element around the fixing part, the ribs are crushed to be substantially flush with the remainder of the carrier part.

25. A sealing means substantially as described herein with reference to and as illustrated in the accompanying drawings 2 to 4, 5 to 6, or 7 to 8. * ** * , * * *. *** * 0 *0 * * * * * I. *

S. *I*s * S *0 * 0 *

SS

25. A sealing means substantially as described herein with reference to and as illustrated in the accompanying drawings 2 to 4, 5 to 6, or 7 to 8. * ** * , * * *. *** * 0 *0 * * * * * I. *

S. *I*s * S *0 * 0 *

SS

1. A sealing means comprising a carrier part and a sealing element, the sealing element being adapted to form a seal against another structure, the carrier part including fixing means adapted to mechanically engage with the sealing element to secure the sealing element to the carrier part.

2. The sealing means of claim 1, in which the sealing element is secured to the carrier part only by the mechanical engagement therebetween.

3. The sealing means of claim 1, in which the carrier part is of plastics and in particular of reinforced plastics.

4. The sealing means of any preceding claim, in which the sealing element is of an elastomer.

5. The sealing means of any preceding claim, in which the fixing means extends within the sealing element.

6. The sealing means of claim 5, in which the fixing means comprises at least one fixing projection that extends from the carrier part into the sealing element such that the sealing element surrounds the fixing means.

7. The sealing means of any preceding claim, in which the fixing means has a proximal end that contacts the carrier part and a free end, S...

the fixing means being constructed and arranged such that a recess is 30 formed between the carrier part and the free end of the fixing means.

S. ***. * * * .* * . * S **

8. The sealing means of claim 7, in which the sealing element is adapted to extend within the recess.

9. The sealing means of claim 7, in which the fixing means tapers from the free end to the proximal end to form the recess.

10. The sealing means of claim 7, in which the fixing means has a cut-out therein that forms the recess.

11. The sealing means of any preceding claim, in which the fixing means comprises a plurality of fixing pins that extend from the carrier part, the fixing pins having recesses formed therein.

12. The sealing means of claim 11, in which the fixing pins are thicker in an axial direction at their free ends than at their proximal ends.

13. The sealing means of claim 11 or claim 12, in which the fixing pins are equally angularly spaced around the carrier part.

14. The sealing means of any of claims 11 to 13, in which the fixing pins have gaps therebetween and that the gaps are narrower adjacent the free ends of each of the fixing pins than they are adjacent the proximal ends of the fixing pins.

15. The sealing means of any of claims 11 to 14, in which, at least one of the tangentially facing sides of each of the fixing pins includes an **. undercut that extends between the free end of the at least one fixing pin and the carrier part. I... * .

16. The sealing means of any of claims 11 to 15. in which both * *I** * tangentially facing sides of each of the fixing pins include an undercut. * ** * * * * **

Thus, the undercuts add to the recess formed by the taper in the axial thickness of the fixing pins to securely mechanically hold the sealing element and carrier part together.

17. The sealing means of any preceding claim, in which the fixing means has slots or holes formed therein.

18. The sealing means of any preceding claim, in which the sealing element includes a primary sealing portion that extends longitudinally to a first height above the carrier part and a secondary sealing portion that extend longitudinally to a second height above the carrier part.

19. The sealing means of claim 18, in which the first height is greater than the second height.

20. The sealing means of claim 18 or claim 19, in which the secondary sealing portion is radially aligned with the fixing means.

21. The sealing means of any preceding claim, in which the carrier part is ring shaped.

22. A method for forming the sealing means of any preceding claim, the sealing means comprising a carrier part having fixing means and a sealing element, the method comprising the steps of; placing the carrier part in a mould; and flowing a resilient material around at least the fixing means to form the sealing element. * * **.*

*. 23. A method according to claim 22, in which the method includes the * 30 step of compressing the sealing element around at least the fixing S.....

* . means. * . . S *S

24. A method according to claim 22, in which the carrier part includes upstanding ribs adjacent the fixing means for providing a barrier to the flowing resilient material and wherein during the step of compressing the sealing element around the fixing part, the ribs are crushed to be substantially flush with the remainder of the carrier part.