TITLE

DISHWASHER PROVIDED WITH A COUPLING DEVICE FOR COUPLING BETWEEN A SPRAY LIQUID PIPE AND A SPRAYING ARM IN A SPRAYING SYSTEM

TECHNICAL FIELD

The present invention relates to a dishwasher according to the preamble to the following claim 1. The dishwasher has at least one height-adjustable washing basket, to which is fitted a spraying arm which is mounted rotatably about a vertical axis in a hub. Leading to this hub is a spray pipe, which in a spraying system can be adapted to the various height positions of the washing basket and of the spraying arm and can be disconnected to allow the basket to be pulled out for the filling and emptying of wash items.

BACKGROUND ART

Through each of SE 8106996-5 and EP 0 401 767, for example, it is known, in the case of height-adjustable washing baskets, to arrange in the rear wall of the washing chamber a coupling device offering two alternative connecting points or docking points with mutually separate height positions. This known coupling device occupies a certain space which can encroach upon the capacity of the washing basket. A spray pipe must in this case be affixed on the underside of the washing basket and be permanently connected to the spraying arm and has to accompany the displacement motions of the basket. The spray pipe has a length approximately corresponding to half the depth of a washing basket and has a rear mouth, the positions of which are not totally distinct as a result of the mobility of the basket.

DISCLOSURE OF INVENTION

The object of the invention is to eliminate the drawbacks of dishwashers having the previously known arrangements involving a coupling device on the rear wall of the washing chamber.

This object is achieved by means of a dishwasher according to the invention, the characteristics of which emerge from the following claim 1.

BRIEF DESCRIPTION OF DRAWINGS The invention will be described in greater detail below on the basis of an example with reference to the appended drawings, in which: fig. 1 is a front view of a dishwasher with open or removed door and removed lower washing basket, fig. 2 is a vertical section through the dishwasher along the line A-A in fig. 1 , fig. 3 and 4 show on a larger scale a partial view of a washing basket with a coupling device in separated and connected position.

MODE(S) FOR CARRYING OUT THE INVENTION

Fig. 1 and 2 show the main structure of a dishwasher according to the invention. The machine is made up of a box-shaped housing 1 usually dimensioned as a module for installation in a fixture, for example a kitchen fixture. The housing encloses a washing chamber 2, which is delimited by two mutually opposing side walls 3, 4, a rear wall 5, a top part 6, a bottom part 7 and, at the front, a door 8 (partially illustrated). The latter is transposable between a closed position, closing off an opening to the washing chamber, and an open position for the loading of wash items that are placed in washing baskets, which are normally two, three or more in number. An upper washing basket 9 is displaceable with rollers 10, 11 on guides 12, 13 in the depth direction, i.e. in the direction of the double arrow 14 into and out of the washing chamber, to allow loading and unloading of the wash items. A lower washing basket 50 is correspondingly disposed in the bottom of the washing chamber 2 and is displaceable out of and into this.

The washing basket is adjustable also in the height direction, as indicated with the double arrow 15, for example between two height positions for adaptation to different sizes of the wash items. This is possible by virtue of the rollers 10, 11 being coupled to the washing basket by means of a height-

adjustment mechanism, which can be of known type and can be provided with a releasable locking mechanism which holds the washing basket in its upper position.

In order to carry out the cleaning of the wash items, for example crockery, glass, cutlery, plastics containers, etc., the dishwasher is operated according to a washing program, under which the wash items are sprayed with water with added detergent and rinsed with water, possibly with added rinsing agent, all at a chosen elevated temperature. To this end, the dishwasher incorporates a spraying system 16, which is coupled to pressurized water for the water supply. Water, added in batches, is circulated in the washing chamber 2 with a circulating pump (not shown), which drives round the washing liquid and is sprayed over the wash items from rotary spraying arms, whereof a lower spraying arm 17 and an upper spraying arm 18 are shown. The lower spraying arm 17 is rotatably mounted in the bottom of the washing chamber 2, beneath the lower washing basket 50.

The upper spraying arm 18 is supported by means of a hub 19 rotatably about a vertical axis and is attached to the upper washing basket 9, more precisely via a holding fixture on the underside of the basket. The spraying arm has a plurality of spray nozzles 21 , through which the washing liquid or the water is sprayed out during rotation of the spraying arm, which is driven by means of the water flow. The washing liquid or the water is supplied to the upper spraying arm 18 via a spray feed pipe 22, which extends from the bottom part 7 of the washing chamber 2 and is coupled on the inlet side to the circulating pump, or to the pressurized water inlet, depending on the phase in the washing process. The lower spraying arm 17 is virtually directly connected to the intake or the circulating pump, which sucks up accumulated liquid in the bottom of the washing chamber. Once the phase is completed, used liquid is pumped out through the outlet. The spray feed pipe 22 runs at the bottom along the bottom part 7 with a lower spray pipe part 23 to the rear wall 5, and with an upright or vertical spray pipe part 54 up to level with the

upper washing basket 9 supporting the upper spraying arm 18. At this level, the spray feed pipe 22, integrated with an upper, rigid and self-supporting spray pipe part 24, extends straight out from the rear wall 5 toward the spraying arm 18, more precisely its holding fixture.

In order to allow the displacement motions of the washing basket 9, on the one hand displacement in the depth direction and on the other hand adjustment in the height direction, a coupling device 25 is provided for connection and disconnection of the upper spraying arm 18 in relation to the spray feed pipe 22. To this end, the coupling device has a fixed coupling part 26, which, according to the invention, sits on the free end 27 of the upper projecting spray pipe part, and a coupling part 28, which is movable together with the displacement motions of the washing basket 9 and of the upper spraying arm 18.

According to the invention, the movable coupling part 28 is attached to the hub 19 of the spraying arm 18 or its holding fixture and forms with these an integrated unit 29. The movable coupling part 28 consists of two coupling members 30, 31 , situated at different heights, in order alternately to be connectable to the fixed coupling part 26 according to the chosen height position of the upper washing basket 9.

In fig. 2, the washing basket 9 is shown in somewhat pulled-out position, the coupling device 25 being in the disconnected state.

The structure of the coupling device 25 can best be seen from the enlarged partial views in fig. 3 and 4. The two coupling members 30, 31 are of the female parts type and are constituted by an upper and a lower pipe socket 32, 33 each having a respective inlet opening 34, 35, to which the fixed coupling part 26 is intended to alternatively be connected as a docking unit. The coupling part 26 is therefore of the male type, having a conical end with guide surfaces 36, which end at the front in an actuating end 37. The guide

surfaces are open to the admission of washing liquid under pressure in the docked position. The guide surfaces 36 can be configured, for example, as legs or ribs, for example two, three or four legs 51 , 52, 53, which emanate from the tubular shell wall 55 of the coupling part 26 and meet in the actuating end 37. Between the legs 51 , 52, 53, openings 56, 57 are formed for the admission of washing liquid.

In order that each of the two coupling members 30, 31 of the movable coupling part 29 shall be either open or closed, both are provided with a respective non-return valve 38, 39, in the example in the form of self-closing valve flaps. These are foldable about their respective folding joint 40, 41 , which advantageously have a built-in spring function which aspires to the closed position. Inside the valve flaps 38, 39 there is situated a flow chamber 42, which is enclosed in the movable coupling part 28 for the passage of liquid under pressure down to the hub 19, which, apart from forming the bearing 43 for the spraying arm 18, has a cavity 44 for passage of the washing liquid out to the inner cavity 45 of the spraying arm 18 via the bearing. The integrated unit 29 therefore has a number of functions and firstly constitutes a holding fixture for the hub 19 supporting the spraying arm 18, secondly forms that part of the coupling device which is movable with the basket, with two docking alternatives, and thirdly provides passage for the spray liquid from the spray feed pipe 22 to the spraying arm 18. The unit, more precisely the holding fixture, can be fixed to the washing basket 9 by snap fasteners 46, 47 for snap-locking to wires 48, 49 in the washing basket.

Fig. 3 shows the coupling device in the disconnected state, with the washing basket in its lower height position and somewhat pulled out. In this case, the fixed coupling part 26 is outside the movable coupling part 29 and thus both valve flaps 38, 39 are in the closed position. When the washing basket is pushed into its pushed-in position, the fixed coupling part 26 is inserted into the upper pipe socket 32 if the washing basket is in its lower position. When the actuating end 37 of the coupling part 26 makes contact with the valve

flap 38, this is opened by the mechanical force exerted by the actuating end and is folded away about its folding joint 40, at the same time as the open coupling part 26 connects in a seal-tight manner to the internal shell surfaces of the pipe socket 32 by means of an elastic sealing ring 58. After this, the system can be pressurized and washing liquid fed in through the spray pipe and its projecting part 24 and through the openings 56, 57 in the coupling part 26, and down through the flow chamber 42 to the hub 19. At the same time, the second valve flap 39 is held closed by its spring force in the folding joint 41 , reinforced by the liquid pressure in the flow chamber 42. By suitable configuration of the valve flaps, it is ensured that, in the closed position, they butt against stop faces, for example beveled edge surfaces. As a result of the excess pressure, washing liquid can flow out via the hub 19 and out through the nozzles of the spraying arm.

When the washing basket 9 is transposed to its upper height position, the lower pipe socket 33 is level with the horizontally projecting upper spray pipe part 24 and, when the washing basket is pushed in, the lower valve flap 39 instead is folded in, while the upper valve flap 38 is held closed and corresponding functioning is obtained upon the inflow of washing liquid.

As can best be appreciated from fig. 1 , the upper washing basket is configured such that it provides room for an upper part of the movable coupling part 29 and the upper projecting spray pipe part 24. Alternatively, these parts can be placed fully below the upper washing basket 9.

The invention is not limited to the above-described examples shown in the drawings, but can be varied within the scope of the following claims. For example, more than two, for example three height positions, are conceivable, in which case there is a need for three coupling members, i.e. pipe sockets with valve flaps within, at different heights. Also conceivable is an intermediate basket, which can be height-adjusted and can be provided with a dockable spraying arm.