GB2297588A

GB2297588A - Air duct sealing in a laundry drier

Info

Publication number: GB2297588A
Application number: GB9601611A
Authority: GB
Inventors: Dieter Knopp
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-02-02
Filing date: 1996-01-26
Publication date: 1996-08-07
Anticipated expiration: 2016-01-26
Also published as: ITMI960107A1; ITMI960107A0; DE19503367A1; GB9601611D0; DE19503367C2; GB2297588B; HK115897A; IT1281703B1

Description

4 2297588 AIR DUCT SEALING IN A LAUNDRY DRIER The Present invention

relates to a laundry drier and has particular reference to air duct sealing in a domestic drier.

In German published specification 1 710 551 there is disclosed a laundry drier in which an air entry region at the rearward end wall of the drier laundry drum is drawn flatly into the interior of the drum and forms an annular shoulder at the rim of the recessed portion. A stripshaped felt seal, which surrounds a drying air exit opening and in the relieved state forms a flat cylinder, is mounted at a stationary drying air channel. During the assembly, the rim of the felt strip,which is directed radially outwards and at the side of the drum,tilts axially inwards driven by the annular shoulder of the rearward drum base and comes into sealing contact with the annular shoulder. Although the internal pressure built up by the feed air in the channel can urge this rim of the felt strip against the annular shoulder, consolidation processes in the course of continuing operation of the drier with sealing in that manner will soon lead to leakage losses at the sealing ring.

Moreover, this kind of seal can compensate for only slight axial production tolerances of the drum and of the bearing at the rear end wall of the drum.

There thus remains a need for a sealing arrangement which may produce a sealing effect automatically during assembly, compensate for tolerances in the order of magnitude of up to, for example, 10 millimetres and retain its function over a longer service life.

According to the present invention there is provided a laundry drier comprising a substantially cylindrical laundry drum which is rotatable about an approximately horizontal axis, in drying operation is flowed through substantially axially by drying air and for this purpose has at 1 least one Opening, which opens into a stationary drying air duct and the mouth of which is surrounded by at least one annular seal fastened at least indirectly at the drying air channel, in one of the base or end walls of the drum cylinder, characterised in that the annular seal comprises a resilient lip, which in the relieved state is approximately radially oriented as seen in cross-section and a sealing portion of which has an axial degree of freedom for compensating for production tolerances and is provided with a textile-like lining at its substantially axially oriented surface lying against the drum end wall.

The aDproximately radial arrangement of the lip, the sealing portion of which has an axial degree of freedom, is able to compensate for production tolerances over the expected range thereof. At the same time, such a lip can be a body which is producible in simple manner from resilient material and the application of a textile-like lining to the sealing surface lying against the base wall does not represent a substantial increase in expenditure. The elastic restoring forces within the material are sufficiently strong to keep the lip constantly in contact against the end wall. During the assembly of the drum in the drier housing, the production of the sealing effect does not require any special action, because the sealing portion automatically lays itself, by its axially oriented surface lined in the manner of a textile, against the sealing annular surface of the end wall.

Preferably, the lit) is an integral component of a profile ring which is adhesively connected by its annular surface remote from the lip to a stationary part of the channel and is rooted, by its rim close to the axis, to the connecting part of the ring. This construction of the ring enables a simple assembly of the seal, wherein the ring connecting 1 surface can be arranged so that the sealing force does not load the adhesive bond. An adhesive bond can be dispensed with if the ring is undersized by a certain degree and is tightened around the stationary part of the drying air channel by inherent stress in the constituent material of the ring, for which purpose the material must be sufficiently elastic.

A textile-like lining of the lip can, in advantageous manner, be formed by the surface, which lies against the end wall, being flockcoated by a textile. Textile surfaces of that kind are known and can be readily produced in a processing step during the production of the ring.

In another embodiment, the lip together with a support ring is fastened to the rim of a flat cylindrical pot of the drying air channel so that its sealing projection projects beyond the pot rim. In such a case, the lip can consist of a simple flat ring which is supported in the fastening region by a similarly simple sheet metal ring and which is screw-connected or riveted thereto at the pot rim and has a maximum possible degree of freedom for compensation for tolerances.

Advantageously, the textile-like lining can be a felt-like strip which is fastened to the surface of the lip which lies against the end wall. This, too, is only a simple annular felt strip which does not impose special production requirements. The fastening can be by adhesion or a seam.

Advantageously, the portion of the drum end wall opposite the lip contacting surface can be deep-drawn annularly, in the manner of a bead, outwardly of the drum. A circular line of high area] pressure thus results for the seal, which can also withstand greater air pressure in the air duct. Wear-resistant nitrile rubber has proved to be a 1 1 particularly suitable material for a lip of that kind.

Embodiments of the invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a schematic vertical section of a rearward portion of a laundry drum, which is mounted at a rear wall of a first laundry drier embodying the invention; and Fig. 2 is a detail view, corresponding to the encircled area II of Fig. 1 and to an enlarged scale, of a second drier embodying the invention.

Referring now to the drawing there is shown in Fig. 1 Dart of a laundry drier comprising a laundry drum 1 mounted to be rotatable about a horizontal axis 2 and, in drying operation, is flowed through substantially axially by drying air as indicated by arrows 3. For this purpose, the base or end wall 4 of the drum 1 has a number of openings 5, which correspond with an opening 6 of a stationary drying air channel 7.

The mouth of the channel 7 is represented by a pot-like flange 8, through which drying air for the channel 7 passes into the drum by way of the openings 6, of which only one is illustrated here, and the openings 5, of which only one sieve-like opening is illustrated.

An annular seal 9, which is formed by a profile ring 10 and an elastic lip 11, is fastened to the outward side of the flange 8. The ring 10 can be fastened, at its surface facing the axis 2, by adhesion to the outward surface of the flange B. Adhesive fastening can be dispensed with if the ring 10, which is produced of elastic material such as rubber, in the initially relieved state before the assembly has a smaller internal diameter than the external diameter of the flange. The profile ring then sits firmly on the flange by inherent stress after assembly.

In order that the lip bears sufficiently tightly against the end wall 4 of the drum and to keep friction between the lip and the end wall low, the axially oriented surface of the lip 11 is provided with a textile- lining, which is not illustrated in detail. The lip 11 has an axial degree of freedom 12, by which production tolerances at the laundry drum 1 and at its bearing as well as at a rear wall 13 of the housing can be compensated for to a significant degree. For compensating for such tolerances, the lip 11 can pivot rearwardly about its root 14 so that the axially oriented surface of the lip always lies against the corresponding surface of the end wall 4 of the drum 1.

Alternatively to adhesive fastening of the ring 10 to the outward side of the flange 8, the ring can be adhesively fastened directly to the rear wall 13 of the housing. In that case, the sealing force would act in the direction towards the adhesion surface so that the adhesion cannot be readily destroyed by the sealing force.

In an alternative embodiment shown in Fig. 2, the lip 15 is fastened by means of screws 17, together with a support ring 16, to the rim of a flat cylindrical pot 18 of the channel 7 in such a manner that the sealing portion 19 projects beyond the rim of the pot 18. The lip 15 consists of an annular nitrile rubber ring which is improved in its elasticity by encircling annular grooves arranged displaced relative to each other at both sides. The sectional illustration of the lip 15 shows a relieved state in which the drum 1 is not yet assembled. After assembly of the drum, the portion 20 of the end wall 4, which portion is here deep-drawn annularly - in the manner of a bead - outwardly of the drum, presses against a felt strip 21, which is sewn onto a sealing portion 19 of the lip 15. In that case, the sealing portion 19 of the 6 lip 15 is deflected towards the end wall 13 according to the depth of entry of the bead portion 20.

A contact pressure force sufficient for sealing is exerted even if the contact line between the end wall portion 20 and the strip 21 lies in a plane 22. However, in the case of a large permitted production tolerance 12 the contact line can lie in a plane 23, which is up to 10 millimetres further back towards the rear wall 13.

A

Claims

- 7 CLAIMS

1 A laundry drier comprising a laundry drum, which is mounted to be rotatable about a substantially horizontal axis and has an air inlet in an end wall thereof, a stationary air feed duct communicating with the inlet, and an annular seal for sealing between the inlet and the duct, the seal comprising a resilient lip which in a relaxed state is directed substantially radially of the drum when seen in cross-section thereof and which has a sealing portion with a textile-like covering at a surface thereof sealing against the drum end wall in a sealing state of the seal, the sealing portion having freedom for axial movement to compensate for tolerances in the relationship of the drum and duct.

2. A drier as claimed in claim 1, wherein the seal further comprises a ring which is integrally connected with the lip and which is attached at an annular surface remote from the lip to a surface portion of the duct.

3. A drier as claimed in claim 2, wherein the lip is connected to the ring in the region of attachment of the ring to said surface portion of the duct.

4. A drier as claimed in claim 2 or claim 3, wherein the ring attached to said surface portion of the duct by adhesion.

5. A drier as claimed in any one of the preceding claims, wherein the textile-like covering is a textile flocking.

is 6. A drier as claimed in claim 1, wherein the seal further comprises a seal which is connected to the lip and which is so attached to an annular ? 1 a protrusion of the duct that the sealing portion of the lip projects outwardly of the protrusion.

7. A drier as claimed in claim 5, wherein the textile-like lining is a felt-like strip.

9. A drier as claimed in any one of the preceding claims, wherein the sealing portion of the lip seals against an outwardly protruding annular bead at the drum end wall.

10. A drier as claimed in any one of the preceding claims, wherein the lip comprises wear-resistant nitrile rubber 11. A laundry drier substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

12. A laundry drier substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawings.