GB2111142A

GB2111142A - Gasket assembly for a laundry dryer

Info

Publication number: GB2111142A
Application number: GB08235497A
Authority: GB
Inventors: Alfred Hoffmann; Horst Sperling
Original assignee: G Bauknecht GmbH
Current assignee: G Bauknecht GmbH
Priority date: 1981-12-12
Filing date: 1982-12-13
Publication date: 1983-06-29
Also published as: NL8203937A; GB2111142B; DE8136238U1

Abstract

The invention is a gasket assembly for a laundry dryer for disposition between a rear wall of the housing of the dryer and an end wall of the laundry drum. The assembly comprises an elastomeric face seal ring support (22) formed of a base portion 20, an S-shaped elastic web (23) and a U-shaped receiving groove 24 for a felt ring gasket 21, the gasket 21 being urged into sealing engagement by a resilient annular body 27 interposed between the base 20 and the underside of the receiving groove 24. <IMAGE>

Description

SPECIFICATION Gasket assembly for a laundry dryer This invention relates to a gasket assembly for a laundry dryer.

A laundry dryer with such a gasket assembly has previously been proposed in German Offenlegungsschrift No. 2,601,733. An elastic web of a face seal ring support is designed as a double web, so that a gasket support of tubular cross-section for a felt gasket is formed between these two webs, the base part connecting them at their base and a U-shaped receiving groove connecting them at their free end. A gasket support of this type is primarily suitable against the heat loads occurring in a laundry dryer. With appropriate dimensions of the web crossLsections and ventilation of the tubular gasket support, the spring properties are provided even when there are relatively large clearance tolerances between the inlet and outlet orifices and even in the event of deflections of the laundry drum, so that, in theory, a seal is obtained over a long period of service.

However, it has been shown, in practice, that tolerances in the wall thickness of up to 0.5 mm occur during production of the face seal ring support, and also the Shore hardness of the rubber is subject to certain tolerances. Such tolerances vary the spring properties to a considerable extent, that is to say the greater the oversize, the harder the spring characteristic, and vice versa.When a face seal ring support having dimensional variations up to the upper tolerance limit is fitted on a dryer in which the clearance between the inlet and outlet orifices is at the lower tolerance limit, such high pressure forces of the felt-ring gasket on the end wall of the laundry drum are obtained that, on the one hand, needlessly high drive forces are necessary for the laundry drum and, on the other hand, the felt gasket is subjected to unnecessarily severe abrasion, so that after a short period of operation the felt gasket is destroyed and consequently the efficiency of the dryer is considerably impaired.

A gasket assembly for the same purpose was disclosed in German Utility Model No. 7,901,997, and in this the face seal ring support is made, in one piece with the felt gasket, from a tubular piece of felt, the enclosed space of which contains a tubular elastic foam ring for producing the necessary pressure force. Such a gasket certainly meets the requirements demanded of it as regards thermal resistance and an approximately equal pressure force even in the case of relatively large tolerances.

However, a disadvantage of this gasket assembly is the enormous consumption of expensive felt material in making it into a tube.

Finally, it has previously been proposed to make the gasket support only of foam material to which the felt sealing ring is glued. Such gaskets have not proved appropriate, since the foam material does not withstand the heat loads originating from the stream of dry air.

An object of the invention is to provide a gasket assembly for a laundry dryer of the aforementioned type, which is designed so that even relatively large dimensional variations in the face seal ring support and also large tolerances in its Shore hardness exert no negative influence at all on the pressure force of the felt-ring gasket. It will be possible to produce the gasket at favourable cost with materials which have proved appropriate in practice.

According to the present invention, there is provided a gasket assembly adapted to be disposed between an outflow orifice for a stream of dry air from a dry air ducting channel on a housing rear wall and an inflow orifice in the rear laundry-drum end wall of a laundry dryer, consisting of an elastomeric face seal ring support capable of being fastened by means of a base portion thereof to the housing rear wall at the outflow orifice and which has an elastic web which is directed from the base portion towards the drum end wall and the free end of which is provided with a receiving groove of U-shaped cross-section for a gasket for sliding on the drum rear wall, characterised in that a) the elastic web is S-shaped and is directed away in the direction of the drum end wall from the base portion side towards the dry-air ducting channel, the free end of which and the U-shaped receiving groove for the gasket extends parallel to the base portion from the end of the S-shaped web, b) a resilient annular body is located in the space between the base portion and the underside of the receiving groove.

Because the elastic web is designed in the form of a horizontal S which is anchored at the baseportion end and at the end of which the U-shaped receiving groove for the felt gasket continues parallel to the base portion, a face seal ring support which is inherently perfectly variable has been provided. Because a resilient annular body, which may be in the form of a foam ring, is inserted in the space between the base portion and the underside of the receiving groove, a pressure force for the gasket, which is specific over a large tolerance range, is imparted to the inherently variable face seal ring support. The resilient annular body, which is highly susceptible, to heat is thermally protected from the side of the stream of dry air by the S-shaped connecting web.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing in which: Fig. 1 shows a laundry dryer in a vertical partial section through the relevant region of the housing and rear wall of the laundry drum, Fig. 2 shows a gasket according to the invention in an enlarged sectional representation.

Fig. 1 illustrates, in a vertical partial section, merely the rear bearing region of a laundry dryer necessary for understanding the invention. The laundry-dryer housing as a whole is denoted by reference numeral 10. In housing rear wall 1 a laundry drum 12 is rotatably mounted in a bearing 13. The housing rear wall 1 1 has a dry-air ducting channel 14 which comes from the housing base region (not shown) and an outflow orifice 15 which is located centrally round a bearing shaft 18. In a rear end wall 16 of the laundry drum 12, inflow orifices 17 for the passage of dry air is also arranged, in the form of a plurality of relatively small bores, centrally round the bearing shaft 18.

During the drying process, heated air flows through the dry-air ducting channel 14 to the outflow orifice 15 and into the inflow orifices 17.

So that the stream of dry air flows exclusively into the laundry drum 12 and does not pass between the laundry drum 12 and the housing 10, a gasket assembly 19 is provided between the outflow orifice 1 5 on the housing rear wall 1 1 and the inflow orifice 1 7 on the rear end wall 16 of the laundry drum. The gasket arrangement 19 is fastened by means of a base portion 20 the housing rear wall 1 for example by glueing, and embedded in the side of the gasket facing away from the base portion 20 is a felt ring gasket 21 which slides on the end wall 16 of the laundry drum 12 to make a seal.

In an enlarged representation, Fig. 2 shows the gasket assembly 19, in cross-section, in its design according to the invention. The gasket assembly 19 includes a face seal ring support 22 formed as an extension of the base portion 20, an elastic web 23 and a U-shaped receiving groove 24 for the felt ring gasket 21, the foregoing components being made of rubber synthetic plastics material or the like.

According to the invention, the elastic web 23 is directed away from the drum end wall on the base-portion side 25 and towards the dry-air ducting channel 14 and is designed in the form of a horizontal S, at the end of which the U-shaped receiving groove 24 for the felt ring gasket 21 extends parallel to the base portion 20 of the gasket assembly. A resilient annular body in the form of a foam ring 27 is located in the interspace between the base portion 20 and the underside 26 of the receiving groove 24. The felt ring gasket 21 is glued into the U-shaped receiving groove 24.

The great advantage of such a gasket assembly is that because of the S-shaped web 23, the face seal ring support 22 exerts no pressure forces on the felt ring gasket 21 and that the face seal ring support 22 can be produced with large tolerances.

The pressure forces on the felt ring gasket 21 and consequently on the rear end wall 16 of the drum are applied and determined exclusively by the foam ring 27. This means, in practice, that as a result of this gasket assembly 1 9 according to the invention relatively large tolerances in the clearance between the housing rear wall 1 1 and the drum end wall 16 can be overcome with an almost uniform pressure force on the felt ring gasket 21. This gasket also reacts very sensitively, without great changes in the pressure force, to deflections or wobbling movements of the laundry drum 12.

According to a further feature of the invention, the S-shaped web 23 forms with its end 28 a first short leg, directed perpendicularly to the end wall 16 of the laundry drum, of the U-shaped receiving groove 24 for the felt gasket 21. It is especially advantageous if the base portion 20 is provided at its free end 29 with an angled portion 30 directed perpendicularly towards the underside 26 of the receiving groove 24. The foam ring 27 is retained positively between the base portion 20 and the underside 26 of the U-shaped receiving groove 24 by the angled portion 30 and by the end portion 28 of the S-shaped web 23, so that there is no need for any adhesive bonding of the foam ring 27, which, in the final analysis, would impair its spring characteristic and make assembly more expensive.

The face seal ring support 22 is designed as a shaped or moulded article, whilst the felt ring gasket 21 and the form ring 27 are formed from a finite strip, the foam ring 27 being connected, and advantageously glued, to the ring on its two end faces.

Claims

1. A gasket assembly adapted to be disposed between an outflow orifice for a stream of dry air from a dry air ducting channel on a housing rear wall and an inflow orifice in the rear laundry-drum end wall of a laundry dryer, consisting of an elastomeric face seal ring support capable of being fastened by means of a base portion thereof to the housing rear wall at the outflow orifice and which has an elastic web which is directed from the base portion towards the drum end wall and the free end of which is provided with a receiving groove of U-shaped cross-section for a gasket for sliding on the drum rear wall, characterised in that a) the elastic web is S-shaped and is directed away in the direction of the drum end wall from the base portion side towards the dry air ducting channel, the free end of which and the U-shaped receiving groove for the gasket extends parallel to the base portion from the end of the S-shaped web, b) a resilient annular body is located in the space between the base portion and the underside of the receiving groove.

2. A gasket assembly according to Claim 1, in which the S-shaped web forms with its end a first short leg, directed substantially perpendicularly to the drum end wall of the U-shaped receiving groove for the gasket.

3. A gasket assembly according to Claim 1, in which the base portion is provided at its free end with an angled portion directed perpendicularly towards the underside of the receiving groove.

4. A gasket assembly according to Claim 3, in which the resilient annular body is retained positively by an end portion of the S-shaped web and the angled portion of the base portion end.

5. A gasket assembly according to any preceding claim, in which the resilient annular body is formed from a foam strip.

6. A gasket assembly as claimed in any preceding claim, in which the face seal ring support is of rubber.

7. A gasket assembly as claimed in any preceding claim in which the gasket is in the form of a felt ring.

8. A gasket assembly substantially as hereinbefore described with reference to the accompanying drawing.