WO 2014/122162 PCT/EP2014/052220 1 5 DETERGENT DISPENSER 10 The invention relates to a detergent dispenser for a washing machine and a washing machine comprising such a detergent dispenser. EP 1 449 951 B2 discloses a washing machine having a detergent dispenser. The detergent dispenser comprises a dispenser housing and an extractable drawer arranged in the 15 housing. According to an embodiment the drawer comprises slidebars adapted to slide along inner rails of the housing to slide the drawer in and out of the housing. Two lateral slidebars guide the drawer horizontally and two additional slidebars support and guide the drawer vertically. 20 It is an object of the invention to provide a detergent dispenser and a washing machine having a detergent dispenser which is easy to manufacture and reliable in use. The invention is defined in claim 1 and 13, respectively. Particular embodiments are set out in the dependent claims. 25 According to claim 1, a detergent dispenser comprises a dispenser housing, an extractable drawer arranged in the dispenser housing and a guiding arrangement provided between the drawer and the housing for slidably guiding the drawer in the housing along a pull out/push-in (inserting/withdrawal) direction. The guiding arrangement comprises at least 30 one drawer guiding device and at least one housing guiding device adapted to engage with each other, wherein the at least one housing guiding device at least partially surrounds the drawer guiding device or vice versa. The at least one drawer guiding device partially surrounds the housing guiding device. In particular the guiding arrangement comprises at least one guiding device pair, wherein one of the (housing or drawer) guiding devices 35 partially surrounds, encompasses or grips around the other (drawer or housing) guiding device. For example the drawer (or housing) guiding device may be a protruding device or element which is partially surrounded by the housing (or drawer) guiding device.
WO 2014/122162 PCT/EP2014/052220 2 The at least one drawer guiding device and the at least one housing guiding device (the at least one guiding device pair) are engaged such that a surface portion of the at least one drawer guiding device is contacting a surface portion of the corresponding one of the at 5 least one housing guiding device and both surface portions are adapted to slide along each other. In particular no bearing (for example no ball or roller bearing) is used and/or no auxiliary or additional element inserted between the mating guiding devices (except the below mentioned friction-reducing layer or coating). The partially surrounded (housing or drawer) guiding device in combination with the contacting surface portions results in 10 'smooth' and safe mating of the guiding devices. In particular the interacting and/or contacting and/or overlapping surface portions of the mating guiding devices have no edges or sharp angles. The cross-section of the at least partially surrounded (drawer or housing) guiding device and the mating cross-section of the at least partially surrounding (housing or drawer) guiding device is selected from a partially circular cross-section, or a 15 partially ellipse cross-section. As one guiding device partially surrounds the other, a reliable connection between the guiding devices is provided and additionally the (surrounded) guiding device is protected from external 'pollutants' like e.g. detergent (liquid/powder), water etc. By means of the above described guiding arrangement a cost efficient and easy to produce guiding of the drawer in the housing is achieved which is 20 reliable and fail-safe in use. Preferably the surface portion of the at least one drawer guiding device, the surface portion of the at least one housing guiding device or both surface portions are formed by Teflon or a plastic material having a low coefficient of friction. Thus a user may easily and 25 comfortably slide the drawer in and out of the housing. In particular no gap or a minimal tolerance gap or clearance is provided between the at least one drawer guiding device and the at least one housing guiding device at the regions where the sliding surfaces are in contact during the sliding movement. For example in a cross-section perpendicular to the movement direction A the hollow profile of the receiving one of the guiding devices and 30 the outer profile of the guiding device that is received in the hollow profile are mating with no or only a minimum clearance between each other. Thus it is prevented that dirt or debris attaches to the surface of the surrounded guiding device, as described above. According to a preferred embodiment the surface portion of the at least one drawer guiding 35 device, the surface portion of the at least one housing guiding device or both surface portions are formed by Teflon using one or more of: (i) a Teflon surface coating, (ii) a bi injection forming by providing a plastic material for the bulk of the at least one drawer WO 2014/122162 PCT/EP2014/052220 3 and/or housing guiding device and a Teflon material for the surface portion, or (iii) forming the at least one drawer and/or housing guiding device by Teflon material. All embodiments provide an easy and comfortable inserting/withdrawing of the drawer as described above. 5 Preferably the sliding direction is linear such that the at least one drawer guiding device is adapted to move along a linear direction with respect to the housing, and wherein the at least one drawer guiding device and the at least one housing guiding device are engaged such that they provide a mutual form fit acting in a direction perpendicular to the linear 10 direction. The at least one guiding device pair is engaged with each other, holds on to each other or is fixed to each other such that they cannot be separated perpendicular to the (linear) guiding axis or inserting/withdrawal direction. In particular a one-sided guiding arrangement of the drawer is possible, i.e. one or more drawer/housing guiding device pair(s) may be provided on one side of the drawer. 15 Alternatively or additionally one ore more drawer/housing guiding device pair(s) as described above may be provided between a bottom portion of the drawer and the housing. I.e. a guiding arrangement may be provided between the base of the drawer and the housing. 20 Preferably the partially circular cross section is at least 3000, 2500, 2000, 190' of a full circle or of a full ellipse, such that the respective surrounded guiding device is reliably encompassed and a reliable hold structure is provided. 25 According to a preferred embodiment the guiding arrangement comprises at least two drawer guiding devices arranged on opposing sides of the drawer and at least two corresponding housing guiding devices arranged at the housing. Thus a reliable lateral support is provided for the drawer, such that tilting of the drawer is reliably prevented during sliding-in/-out, even when the drawer is pushed /pulled off-center. 30 Preferred the guiding arrangement comprises at least two drawer guiding devices arranged on one side of the drawer and at least two corresponding housing guiding devices. I.e. only two lateral drawer/housing guiding device pairs may be provided on one side of the detergent dispenser. Alternatively two lateral housing/drawer guiding device pairs may be 35 provided on each side of the detergent dispenser, e.g. four drawer/housing guiding device pairs.
WO 2014/122162 PCT/EP2014/052220 4 According to an embodiment the at least one drawer guiding device is formed in one-piece with the drawer or alternatively the at least one housing guiding device is formed in one piece with the housing. In particular the material of the respective guiding device and the drawer/housing are the same, such that they may be manufactured in one step, e.g. by 5 injection molding. While one guiding device may be provided in one-piece with the drawer or housing, the other guiding device may be attached or fixed to the housing or drawer in a separate step. Alternatively both guiding devices, i.e. the at least one drawer guiding device and the at least one housing guiding device, are formed in one-piece with the drawer and housing, respectively. 10 Preferred the at least one drawer guiding device is fixed to the drawer or the at least one housing guiding device is fixed to the housing. The material of the drawer/housing and the respective guiding device may be different, e.g. the material of the housing/drawer and guiding device(s) may be adapted individually to the specific requirements of the detergent 15 dispenser. For example the material of the guiding devices may have a low friction coefficient and the drawer material may be resilient against detergent or other chemicals. Alternatively the at least one drawer guiding device is fixed to the drawer and the at least one housing guiding device is fixed to the housing. 20 According to an embodiment a clearance is provided between a front edge of the partially surrounded guiding device and (the rear side of) a front panel of the drawer or a front opening of the housing when the drawer is fully inserted in the housing. For example when filling in detergent into the drawer some of the detergent may fall on the exposed guiding device (e.g. of the drawer). When the drawer is pushed into the housing, the detergent on 25 the exposed guiding device is pushed along the guiding device until it falls off at its end (which is at the front edge of the guiding device), for example into the gap. Thus it is provided that no debris (detergent) accumulates on the respective guiding device. Preferably the guiding arrangement is not biased, in particular not biased in vertical 30 direction. I.e. (sidewise or lateral) contact pressure, e.g. due to spring-biased guiding devices, is prevented. Thus less strain is exerted on the drawer/housing and less abrasion on the guiding devices. According to an embodiment, the dispenser housing and/or the extractable drawer is 35 formed as a single-piece or monolithic component. Preferably in form of a single-injection molded component, wherein in case of surface coating with reduced friction preferably co injection is used. Alternatively the dispenser housing and/or the extractable drawer are WO 2014/122162 PCT/EP2014/052220 5 formed from two or three shell elements which are connected together to form a combined component. A washing machine is provided having a detergent dispenser according to any of the above 5 and below described embodiments. Reference is made in detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying figures, which show: 10 Fig. 1 a a perspective view of the washing machine with a partially pulled-out detergent drawer, Fig. 1 a perspective side view of a detergent dispenser of the washing machine shown 15 in Fig. 1 a with the detergent drawer of Fig. 1 a partially pulled-out of the housing of the detergent dispenser, Fig. 2 a perspective side view of the housing of the detergent dispenser shown in Fig. 1, 20 Fig. 3 a perspective side view of the drawer of the detergent dispenser of Fig. 1, Fig. 4 a sectional front view of the detergent dispenser of Fig. 1, 25 Fig. 4a-c details of a guiding arrangement of Fig. 4, and Fig. 5 a top view of the detergent dispenser of Fig. 1. 30 An exemplary washing machine 1 is shown in Fig. 1 a in perspective view. The washing machine 1 has an outer housing or cabinet 30. A loading opening 34 is arranged at the front side of the cabinet 30 for loading/unloading laundry into/out of a drum when a front door 32 of the machine is opened. At the upper front side of the cabinet a control panel 36 is arranged having program control elements for receiving a user selection for the washing 35 program and for indicating to the user the selected program and/or current program states of the machine. In this embodiment an exemplary detergent dispenser 2 is arranged at the upper left front side which receives and temporarily stores washing agents filled in by the WO 2014/122162 PCT/EP2014/052220 6 user. Fig. la shows the detergent dispenser 2 opened such that a detergent drawer 6 is partially extracted from a housing 4 (see Fig. 1) in which the drawer is received when the user has fully pushed-in the drawer 6. 5 Fig. 1 shows a perspective side view of the detergent dispenser 2 for the washing machine shown in Fig. la. The detergent dispenser 2 comprises the housing 4 and the drawer 6 which - as shown in Figs. la and 1 - is partially extracted or pulled-out from the housing 4 along a push/pull direction A. Three detergent compartments 18a-c are provided in the drawer 6, e.g. adapted to receive a detergent and softener for a washing operation. A 10 guiding arrangement is provided between the drawer 6 and the housing 4 to slidably support the drawer 6 in the housing 4 (for sliding the drawer 6 in and out relative to the housing 4). The guiding arrangement comprises a drawer guiding device 8a, 8b on each side of the drawer and a corresponding housing guiding device 10a, 10b at the housing 4. I.e. one pair of lateral guiding devices 8a, 10a and 8b, 10b is provided on each side of the 15 detergent dispenser 2 (Fig. 5). The drawer guiding devices 8a-b are protruding from the drawer body and are shaped in form of a cylinder having an axis parallel to direction A. Correspondingly the housing guiding devices 1Oa-b are formed in form of a hollow partial-cylinder which is adapted to 20 at least partially surround or encompass the respective drawer guiding device 8a-b. Figs. 2 and 3 show perspective side views of the housing 4 and the drawer 6. The drawer 6 is inserted into the housing 4 via the housing opening 16. As shown in Fig. 3, the drawer guiding devices 8a-b do not extend along the complete length of the drawer 6. In this 25 embodiment a clearance or gap 20a-b (Fig. 5) is provided between a front 22 of the drawer 6 and the guiding device 8a-b in direction A. The clearance provides a predefined extension in direction A from the front region of the drawer where no guiding devices 8a, 8b are formed. 30 As can be seen from Fig. 2, the dispenser or drawer housing 4 is formed of two parts. This is a body shell 4a which - besides the liquid openings - is open to the front side to receive the drawer 6 and is open at the top side. The open top side is covered by a substantially flat cover shell 4b which prevents leakage of washing detergents and water to the outside of the housing 4. Alternatively, the housing may be formed of a single-piece or monolithic 35 body formed for example by blow molting. The drawer is formed of two shell elements, which are a drawer base body 6a (shown in Figs. 1 and 3) in which or by which the washing agent chambers and the drawer front 22 are formed and a handle panel 6b which WO 2014/122162 PCT/EP2014/052220 7 is mounted to the basic body at the drawer front 22. The handle panel 6b is shown in Fig. la and is removed for illustrative purposes in Figs. 1 and 3. Fig. 1 shows the detergent dispenser 2 in a partially extracted position (the normal filling 5 position) when detergent is filled into at least one of the compartments 18a-c. It may occur that some detergent is spilled, such that it settles on the (protruding) drawer guiding device 8a-b. When the drawer 6 is pushed into the housing 4, the spilled detergent is pushed along the drawer guiding device 8a-b and wiped away into and downward through the clearance 20a-b. According to the shown embodiment the spilled detergent (or any other debris) is 10 removed from the guiding device 8a-b by simply sliding the drawer 6 into the housing 4. Thus an aggregation of debris or detergent on the guiding arrangement is prevented which may affect adversely its function. Fig. 4 shows a sectional front view of the detergent dispenser 2 of Fig. 1. Figs. 4a-c show 15 details of the guiding arrangement of the detergent dispenser 2, in particular the arrangement of a pair of a housing/drawer guiding device 8a, 10a. The drawer guiding device 8a comprises a circular or substantially circular cross-section with a guiding surface 12a which may comprise Teflon or other low-friction coating to minimize friction during inserting (pushing)/withdrawing (pulling). The housing guiding device 10a comprises a 20 corresponding circular guiding surface 14a which is adapted to receive the drawer guiding device 8a as shown in Fig. 4c. As shown in the Figures, the drawer guiding devices 8a-b are formed in one-piece with the drawer 6 and the housing guiding devices 1Oa-b are formed in one-piece with the housing 25 4, preferably by injection molding. As shown in Fig. 4c the drawer/housing guiding devices 8a, 10a are fitted or mate to each other such that a minimum gap or no gap is provided between the respective guiding surfaces 12a, 14a. Thus the guiding arrangement is free or substantially free of play. 30 The housing guiding device 10a surrounds about 2500 of (the circular cross-section of) the drawer guiding device 8a, in particular surrounds more than 1800 of the drawer guiding device 8a. Thus the guiding arrangement provides a form-fit in horizontal direction, i.e. perpendicular to slide-in/slide-out direction A. 35 Fig. 5 shows a top view of the detergent dispenser 2 of Fig. 1 with a partially withdrawn drawer 6. By providing a guiding device pair 8a, 10a and 8b, 10b on each side of the WO 2014/122162 PCT/EP2014/052220 8 detergent dispenser 2 or drawer 6, which provide a horizontal form-fit, the drawer can be easily and comfortably withdrawn from (and inserted into) the housing without horizontal or vertical tilting relative to the housing 4, even when the drawer 6 is pulled (or pushed) off-center. 5 10 Reference Numeral List 1 washing machine 2 detergent dispenser 4 housing 15 4a body shell 4b cover shell 6 drawer 6a base body 6b handle panel 20 8a-b drawer guiding device lOa-b housing guiding device 12a-b guiding surface (drawer) 14a-b guiding surface (housing) 16 housing opening 25 18a-c detergent compartment 20a-b clearance/gap 22 drawer front 30 cabinet 32 front door 30 34 loading opening 36 control panel A inserting/withdrawing direction