This invention relates to a gasket arrangement, and particularly though not exclusively to a heat-resistant gasket arrangement for a door or an oven, for example a domestic oven.
It is known to provide a door of an oven with a gasket to provide a heat-resistant seal between the door and the body of the oven, and also to prevent escape of cooking smells from the oven into the kitchen. Difficulty can be experienced in securing the gasket to the door by adhesive for example because although high temperature adhesives are available they tend to emit undesirable fumes, at least when initially heated. Oven doors may be made of glass and difficulty can be experienced in securing a gasket to a surface thereof.
US-A-2665458 describes a single tubular gasket that surrounds the front opening in an oven liner and that is adapted to be compressed by the closed door. The gasket is held in position by spring clips US―A―3219026 describes a seal ring that provides a seal between the interior of an oven and an inner glass panel. The seal ring is clamped between the glass panel (10) and the frame member of the oven. The seal ring has a U-shaped portion and a trim ring is inserted between the legs of the U.
One aspect of the present invention provides a gasket arrangement comprising at least two generally elongate gaskets in the form of closed loops, the gaskets being of substantially the same length and arranged to lie side-by-side and substantially parallel to each other, and a plurality of connecting members that secure the gaskets together at intervals spaced apart along each gasket, each connecting member having a first portion secured to one of the gaskets, and a second portion secured to another of the gaskets, the gasket arrangement being arranged so that the gaskets can be positioned on a substrate so that the substrate is located between the gaskets and so that the connecting members pass over a peripheral edge of the substrate to bridge the gaskets.
A second aspect of the present invention provides a gasket arrangement comprising at least two generally elongate gaskets in the form of closed loops, the gaskets being of substantially the same length and arranged to lie side-by-side and substantially parallel to each other, and a single continuous connecting member that secures the gaskets together at intervals spaced apart along each gasket, the gasket arrangement being arranged so that the gaskets can be positioned on a substrate (2) so that the substrate is located between the gaskets and so that the connecting member passes back and forth over a peripheral edge of the substrate to bridge the gaskets.
The connecting members securing the gaskets together in the gasket arrangement according to the first mentioned aspect of the present invention may be, for example, staples.
In one preferred embodimet of the gasket arrangement according to the sceond aspect of the present invention, where a single continuous connecting member is used, the gaskets are loosely sewn together by non-woven stiching of a single length of yarn or thread that passes back and fore between the gaskets in an elongate zig-zag pattern, thus securely interconnecting the gaskets whilst providing a high degree of longitudinal and transverse movement therebetween. In such an arrangement, each portion of the yarn or thread that extends between the gaskets is spaced apart from the next by the zig-zag.
The gaskets may be sewn together by yarn of, for example, glass, metal, PTFE, or polyester.
The gaskets may be braided or knitted from glass-ceramic or other fibre material, and in a preferred embodiment are of substantially circular section. The gaskets may be internally reinforced with a stiffening rod, shaped into a closed rectangular loop, and then elastically secured together by the connecting member.
In embodiments of gasket arrangements in which two, or more, gaskets are loosely secured together by having a single length of thread or yarn sewn therebetween, the maximum separation of the gaskets and also the number of stitches, or lengths of the connecting member, per inch may conveniently be controlled by the sewing machine.
The gasket arrangement of the present invention allows gaskets to be conveniently secured to a substrate without employing adhesive and without the need for any special preparation of, for example drilling of apertures in, the substrate.
Several embodiments of gasket arrangement, each in accordance with the present invention, will now be described, by way of example, with reference to the accompanying schematic drawings, in which:
Referring to the drawings, Figure 1 a shows a rectangular glass panel 2 of the door of an oven that is to be fitted with two glass-ceramic fibre gaskets 4 and 6 interconnected by a plurality of connecting members or staples 8 as shown in Figure 1 b, to provide the assembled arrangement of Figure 1 c. As may be seen more clearly from Figures 2 and 3, the gaskets 4 and 6 are of circular cross-section and are interconnected by the staples 8 by penetration thereinto of respective staple legs 10. Each leg 10 is terminated by a hook or barb 12 that opposes upward withdrawal of the stape 8 from the gasket. The staple 8 is looped at a portion intermediate the legs 10 so as resiliently to urge the gaskets 4 and 6 towards each other.
Figure 3b shows a modified form of staple having two loops in its intermediate portion to provide increased inward pressure on the gaskets 4 and 6. The staple of Figure 3c, has its legs 14 angled towards each other, so that after being forced apart to receive the oven door panel 2 therebetween, the gaskets engaged by respective legs 14 are urged inwardly by the resilience of the staple into contact with the panel 2.
When using the gasket and staple arrangement on a rectilinear substrate such as the panel 2, it is found convenient, as shown in Figure 1 for example, to provide the staples 8 in pairs adjacent corners of the panel 2 with the staple legs penetrably secured into respective gasket on opposing major faces of the panel' with the intermediate staple portions abutting the interconnecting edge of the panel 2.
The gasket arrangement is preferably supplied in assembled forms, such as shown in Figure 1b for example, being dimensioned in accordance with the particular substrate, the glass panel 2 of Figure 1 a for example. The gasket arrangement is then flexed, taking advantage of its natural elasticity, so that it can be slipped over the substrate, as shown in Figure 1 for example.
Figure 4 shows a modified gasket arrangement in which two panels 2 have the gasket 6 forming a peripheral seal therebetween the gasket 4 abutting an opposing surface of one of the panels, and a further gasket 15 abutting an opposing surface of the other panel 2. The arrangement is shown prior to the staples 8 being urged downwardly into contact with the panels 2.
Figures 5 to 7 show a further gasket arrangement 22 comprising two braided or knitted gaskets 24 of glass-ceramic fibres that are connected together by a length, or possibly two or more lengths, of yarn or thread 28 of, for example, glass, metal, PTFE or polyester fibre. The yarn 28 is sewn through the two gaskets 24 in loose fashion, both in the transverse and longitudinal directions, so that the stitches are of the form of discrete non-woven portions 30 extending between the gaskets 24 as an elongated Z. Thus, the gaskets 24 are interconnected by the portions 30 at discrete locations longitudinally thereof. The gasket arrangement 22 thereby produced is very flexible and allows for easy mounting on to a substrate such as the oven glass door 26 with the gaskets 24 on opposing faces thereof with the lengths 30 extending over the edges of the door.
It will be appreciated from Figure 6 that the longitudinal spacing apart of the stitch lengths 30 and the transverse separation of the gaskets 24 may very conveniently be controlled during the sewing operation. By this means, the gasket arrangement 22 can be tailored to suit the required thickness of the substrate and also the required curvature of the gaskets 4 adjacent corners of a rectilinear substrate.
Referring to Figure 8, three gaskets 24 are shown interconnected by a single length of yarn in a manner analogous to that hereinbefore described. It will be appreciated, however, that each adjacent pair of gaskets may be interconnected by a separate thread.
Any of the gaskets shown in Figures 1 to 8 may be internally reinforced with, for example, a metal rod 32, as shown in Figure 9. The reinforced gasket may be fabricated by forming the braided or knitted gasket, of circular cross-section, in an elongate length, threading a metal rod 32 through the braid or knitt and then shaping the gasket into a closed rectangular loop, the ends of the loop being secured together by stapling or sewing.
Material other than glass-ceramic fibre may be employed in the construction of the gaskets, and may comprise glass, ceramic, silica or asbestos fibre material for example, or a combination thereof. Furthermore, the gasket may be formed by weaving, or other suitable means. In general, the gasket may be provided by any suitably-constructed elongate member.
Preferably, as shown in Figure 1 for example, the gasket is of elongate form and is located adjacent .and substantially entirely around the periperhy of the substrate. It will be appreciated that the. precise positioning of the gaskets on the substrate surface can be arranged by a suitable choice of length of the staple legs in the embodiment shown in Figures 1 to 4, or by suitable choice of stitch lengths 30 in the embodiment shown in Figures 5 to 8. It will also be appreciated that the gasket may extend, over a greater or lesser area of the surface of the substrate than shown.
The gasket arrangements of the present invention thus provide convenient ways of securing elongate lengths of gasket together and securing the gaskets over a substrate by inserting clips in the gaskets or by having lengths of a connecting member such as yarn or thread extending between the gaskets at spaced-apart, ie, discrete, locations.