EP2103729B1

EP2103729B1 - Drum washing machine

Info

Publication number: EP2103729B1
Application number: EP09150430A
Authority: EP
Inventors: Hiroshi Kajihara; Kazunori Maeda; Kiyonobu Yoshida
Original assignee: Panasonic Corp
Current assignee: Panasonic Corp
Priority date: 2008-03-13
Filing date: 2009-01-13
Publication date: 2013-03-20
Anticipated expiration: 2029-01-13
Also published as: SG155828A1; MY151690A; RU2401347C1; TW200944634A; CN101532235B; JP2009213804A; CN101532235A; EP2103729A1; CN201372375Y

Description

FIELD OF THE INVENTION

The present invention relates to a drum washing machine, in which a cylindrical rotary drum having a bottom plate is placed in a water tub such that the drum is oriented from an open front toward a rear bottom with its rotary axis kept horizontally or slanting downward. Laundry is put into the drum through a lid provided to a front face of a housing of the washing machine, and the drum is driven with a motor, thereby carrying out at least one of the steps of washing, rinsing, or dehydrating.

BACKGROUND OF THE INVENTION

A conventional drum washing machine includes a lid which is generally formed of a lid unit having a transparent window through which a user can see laundry, and a transparent lid cover fit to the front face of the lid unit for covering the lid unit. Such a drum washing machine is disclosed in, e.g. Unexamined Japanese Patent Application Publication Number 2007 - 68810 (hereinafter referred to as Patent Document 1). Patent Document 1 specifically discusses a transparent cover in its associated drawing, and this cover covers the front face of a lid frame as far as near to the outer rim of the frame. This conventional structure reveals a problem, i.e. fitted sections of snaps, which elastically engage the transparent lid cover with the lid frame and fix the cover to the lid frame, can be seen from the front, so that a fine appearance of the drum washing machine is somewhat spoiled. To overcome this problem, Patent Document 1 thus proposes an opaque decorative plate be fitted onto an outer periphery of the transparent lid cover for exhibiting a fine appearance of the drum washing machine.
However, use of this decorative plate needs additional components and manufacturing steps, thereby incurring an increase in the manufacturing cost. The transparence of the lid cover is actually not needed in a range not contributing to see-through the laundry, yet placement of the decorative plate loses the transparence of the lid cover at the periphery of the cover. As a result, a quality look, compactness, and a fine appearance of the entire lid are spoiled, so that another problem occurs such as an increase in the cost, and degradation in the compactness as well as in the fine appearance of the drum washing machine.
DE 195 15 040 A1 relates to a porthole door for a front-loading washing machine. A porthole door comprises a transparent disk for covering the sight glass of the door, wherein the disk edge is fastened between the aperture ring and the sight glass in the frame such that the edge is surrounded by a holding ring of the frame with small clearance.
US 2006/0117813 A1 relates to a door for a drum type washing machine and a method of manufacturing the door with a decorative part. A front member is attached to the front surface of a door frame. Consequently, the overall strength of the door frame is increased. Especially, a decorative part, which consists of alternating reflective/nonreflective or embossed/depressed patterns, is formed either at the door frame or at the front member. Consequently, the overall appearance of the door is improved, and glare is effectively prevented.
GB 2 237 293 A relates to a window for electrical household appliances. A window for electrical household appliances (washing machines or tumble driers) comprises a transparent cup-shaped element having a substantially hemispherical shape, and a frame element consisting of a single piece of thermoplastic material applied to the peripheral edge of the cup-shaped element. The frame may be moulded in place or moulded before being applied to the glass or plastics window.
JP 2008-253488 A relates to a washing machine. Transparent resin members are provided on a lid for a laundry throw-in opening of a casing of a washing machine. Continuous concave-convex shapes are formed on the reverse surface of the resin members, and the surface is not formed into the concave-convex shapes. The concave-convex shape is formed by adjacently arranging a concave part and a convex part. A unit of a concave-convex part in which the concave part and the convex part are combined is continuously formed in one direction so that a concave-convex row formed by alternately arranging the concave part and the convex part in a continuous manner is constituted.
GB 2 294 698 A relates to a clothes washing machine with an improved door. A clothes washing machine has a washing tub, a drum which is rotatable within said washing tub and which is capable of containing the articles to be washed, an external casing in which there is provided an opening for loading the-articles to be washed into said drum, and a door which is hinged on an edge of said opening and which is capable of sealing closing it. The door is composed exclusively of a closure wall member, a first element constituting one of two portions of a hinge and a second element constituting the catch for the door disposed on the casing. At least one of said first and second elements are permanently fixed to the closure wall member by means of adhesive interposed between the elements and the wall member. It is desirable that the surface portions which carry the adhesive are treated with an opaque coating layer, preferably enamel.
GB 2 118 580 A relates to a window for washing machines. A window for a washing machine comprises a glass member having a circumferential edge which projects outwardly and an annular support of plastics material for the said window. The support comprises two complementary rings which nest together and have two flanges or opposing end portions towards the centre between which the circumferential edge of the glass member is secured after the two rings have been joined together.

SUMMARY OF THE INVENTION

It is a general object of the present invention to provide an improved and useful drum washing machine in which the above-mentioned problems are eliminated.
In order to achieve the above-mentioned object, there is provided a drum washing machine according to claim 1.
Advantageous embodiments are defined by the dependent claims.
Advantageously, a drum washing machine is provided, in which a lid cover is transparent as far as its periphery where the cover is elastically engaged with and fixed to the lid unit. Yet this drum washing machine needs no additional components or assembling steps, so that the washing machine can be inexpensive and compact. On top of that, the fixed sections are not viewed from the outside, so that the washing machine can exhibit its compactness, a quality look, and a fine appearance.
Advantageously, a drum washing machine includes a cylindrical rotary drum having a bottom plate and placed in a water tub such that the drum is oriented from an open front toward a rear bottom while its rotary axis is kept horizontally or slanting downward. Laundry is put into the drum through a lid provided to a front face of a housing of the washing machine, and the drum is driven with a motor, thereby carrying out at least one of the steps of washing, rinsing, or dehydrating. The lid is formed of a lid unit having a transparent window through which a user can monitor the laundry, and a transparent lid cover placed on the front face of the lid unit for covering the lid unit. Multiple engaging tabs are provided on a rear face at the periphery of the cover, and the engaging tabs protrude rearward. Multiple engagement stopper holes to be mated with the engaging tabs are provided to the lid unit. The holes receive the tabs into the lid unit and elastically engage the engaging tabs with engaging sections provided to the lid unit for preventing the tabs from slipping-off. The tabs and the holes form multiple fixed sections which fit and fix the lid cover to the lid unit. The surface of the cover corresponding at least to the fixed sections has a surface shape which at least refracts or disperses a light from the inside when the light transmits through the cover.
The structure discussed above allows preventing at least the wash water, rinse water, or a splash produced by a spin-dryer from leaking to the outside during the respective corresponding steps. On top of that, the user can monitor the laundry through the transparent lid cover and the window while the machine carries out at least one of the steps of washing, rinsing, or dehydrating.
Although the lid cover remains transparent at least in the regions corresponding to the fixed sections, the shape of the lid cover allows the light from the inside of the drum washing machine to be refracted or dispersed when the light transmits through the surface of the cover. Thus the light reflected on the fixed section is at least refracted or dispersed when the light transmits through the surface of the lid cover. As a result, the foregoing structure allows the fixed sections, which are desirably not viewed from the outside, not to be exposed expressly to the human eyes without any additional components or any additional manufacturing steps. As the surface which at least refracts or disperses the light from the inside, a finely-embossed face referred to as a satin-finished face is not employed because the light is diffusely reflected. The surface can be a rough face having a pattern of peaks and valleys instead. The transparence of the regions corresponding to the fixed sections is spoiled little or an interior structure, e.g. the fixed sections, is not exposed to the human eyes.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a perspective view illustrating an essential structure of a drum washing machine in accordance with an embodiment of the present invention.
Fig. 2 shows a sectional view of the drum washing machine shown in Fig. 1.
Fig. 3A shows a sectional view in parts of the drum washing machine shown in Fig. 1, specifically, it shows an inlet/outlet for laundry and a lid closing the inlet/outlet.
Fig. 3B shows a sectional view enlarging a fixed section and its vicinity shown in Fig. 3A.
Fig. 4 shows a perspective view illustrating a relation between a lid cover and a front frame of a lid placed in a water tub of the drum washing machine shown in Fig. 1.
Fig. 5 shows a partial perspective and enlarged view in parts of the front frame shown in Fig. 4.
Fig. 6 shows a front view of the lid cover of the drum washing machine shown in Fig. 1.

PREFERRED EMBODIMENT OF THE INVENTION

An exemplary embodiment of a drum washing machine of the present invention is demonstrated hereinafter with reference to the accompanying drawings. The following embodiment is only an example, and the present invention is not limited to this embodiment. Dimensions in the drawings are sometimes enlarged or reduced for describing structures for a simpler description. Similar elements in the drawings have the same reference marks, and the descriptions thereof are sometimes omitted.

Exemplary Embodiment

Fig. 1 shows a perspective view illustrating an essential structure of the drum washing machine in accordance with the embodiment of the present invention. Fig. 2 shows a sectional view of the drum washing machine shown in Fig. 1.
Drum washing machine 1 in accordance with this embodiment includes rotary drum 2 having a bottom plate, and drum 2 is placed in water tub 3 such that drum 2 is oriented from a open front toward a rear bottom with its rotary axis kept horizontally or slanting downward. A user can put laundry into drum 2 through lid 5 provided to the front section of washing machine housing 4, and rotary drum 2 is driven by motor 6, so that at least one of the steps of washing, rinsing, or dehydrating can be carried out.
Fig. 3A shows a sectional view in parts of the drum washing machine shown in Fig. 1, specifically, an inlet/outlet for the laundry and a lid 5 closing the inlet/outlet. Fig. 3B shows a sectional view enlarging a fixed section and its vicinity shown in Fig. 3A. Fig. 4 shows a perspective view illustrating a relation between a lid cover and a front frame of the lid in the water tub of the drum washing machine shown in Fig. 1. Fig. 5 shows a partial perspective and enlarged view in parts of the front frame shown in Fig. 4. Fig. 6 shows a front view of the lid cover of the drum washing machine shown in Fig. 1.
Lid 5 shown in Figs. 1 and 2 is formed of lid unit 8 having transparent window 7 through which a user can see the laundry from the outside as shown in Figs. 2 and 3A, and transparent lid cover 9 fitted on the front face of lid unit 8. Lid cover 9 has multiple engaging tabs 9a protruding rearward and integrally formed therewith on its rear face along its periphery as shown in Figs. 3A and 4. Lid unit 8 has multiple engagement stopper holes 8b corresponding to engaging tabs 9a. Each one of stopper holes 8b receives tab 9a as shown in Fig. 3A, elastically engages tab 9a with engaging section 8a for preventing tab 9a from slipping-off, and fits and fixes lid cover 9 to lid unit 8. The foregoing structure allows lid cover 9 to fit and cover lid unit 8 on the front face, and lid cover 9 is fixed to lid unit 8. Lid cover 9 has positioning projection 41 as shown in Fig. 4 for being mated with positioning hole 42 provided to lid unit 8. Thus engagement stopper hole 8b, which is prepared to lid unit 8 correspondingly to multiple engaging tabs 9a, is not available only to positioning projection 41 although stopper hole 8b is available to each one of engaging tabs 9a.
The foregoing structure of fixing lid cover 9 to lid unit 8 exhibits an idea about exposing a fixed section 11 formed of engaging tab 9a and engagement stopper hole 8b not expressly to the outside without losing the transparence of lid cover 9. To be more specific, as shown in Fig. 6, lid cover 9's surface in parts 9b respectively corresponding to at least fixed sections 11 are shaped such that the light from the inside can be at least refracted or dispersed while it transmits through lid cover 9. Surface in parts 9b is shaped, e.g. as shown in Fig. 3A and Fig. 3B, and this shape allows refracting or dispersing the light as indicated with the solid line arrow marks or broken line arrow marks in Fig. 3A.
The structure discussed above allows transparent lid cover 9 to fit on the front face of lid unit 8, and allows engaging elastically tabs 9a protruding rearward along the periphery of lid cover 9 with engaging sections 8a of engagement stopper holes 8b provided to lid unit 8 for fixing cover 9 to lid unit 8. When cover 9 is fixed to lid unit 8 as discussed above, lid cover 9's surface in-parts 9b corresponding at least to engagement stopper holes 8b and fixed sections 11 respectively refract or disperse the light from the inside because of their shapes although they remain transparent. As a result, the light reflected on engaging section 8a and fixed section 11, which is formed of engagement stopper hole 8b and engaging tab 9a, is refracted or dispersed as shown with the arrow marks while the reflected light transmits through surface in-parts 9b of lid cover 9. The structural elements desirably not to be exposed to the outside, such as engaging section 8a, cannot seen expressly with human eyes because the light is refracted or dispersed as shown with the solid or broken arrow marks. This structure needs no additional components or no additional assembling steps.
A fine-embossed face is not employed as surface in-parts 9b because the fine-embossed face invites diffuse reflection which somewhat loses the transparence. In stead, a rough face with a pattern of peaks and valleys is employed because it hides desirably-invisible structures such as engaging section 8a from the human eyes or prevents the shades thereof from being reflected.
The structure discussed above allows preventing the wash water, rinse water, or a splash produced by a spin-dryer from leaking to the outside during the respective corresponding steps with lid 5 closed. The user can monitor the laundry through transparent lid cover 9 and window 7 while the machine carries out the steps of washing, rinsing, or dehydrating. On top of that, as shown in Figs. 3A, 3B, and 5, surface in- parts 9b placed along the periphery of lid cover 9 correspond to at least the locations of engaging sections 8a, and the shape of surface in- parts 9b are modified, with their transparence maintained, such that the light reflected on fixed section 11 can be refracted or dispersed. As a result, desirably-invisible structural elements such as engaging sections 8a are kept not seen expressly with the human eyes while lid cover 9 maintains its transparence or transparent feeling, and yet, lid cover 9 exhibits a quality look. On top of that, the modification provided to surface in-parts 9b needs no additional components or no additional assembling steps, so that the structure discussed above incurs no increase in the manufacturing cost of the drum washing machine. To be more specific, the modification provided to the surface includes, e.g. a rough face having a pattern of peaks and valleys, which prevents the shade of fixed sections 11 from being reflected to the outside, but excludes a fine-embossed face which incurs the diffuse reflection that loses transparence greatly enough to hide the interior structures from the human eyes. Lid cover 9 with surface in-parts 9b placed along the periphery as shown in Fig. 6 and having the foregoing rough face with the pattern of peaks and valleys exhibits somewhat a decorative appearance.
Lid cover 9 is formed of resin, in general, such as synthetic resin. As shown in Fig. 3A and 3B, lid cover 9 extends around the outer wall of lid unit 8 and covers lid unit 8 with its extending and surrounding wall 9c. End face 9d of surrounding wall 9c includes engaging tabs 9a integrally molded with lid cover 9. Lid unit 8 includes, along its periphery, projecting wall 8d projecting outward from the periphery of lid unit 8 and having stepped face 8c confronting end face 9d. Engagement stopper hole 8b extends through this projecting wall 8c from the front to the rear. The foregoing structure allows transparent lid cover 9 to extend around the outer wall of lid unit 8 and covers lid unit 8, so that the human eyes along a slant line from the front-side or the front-upper into the interior can be blocked. As a result, lid cover 9 extends its transparent wall uniformly to a wider area including the periphery, so that drum washing machine 1 can exhibit an appearance of better quality look.
Fixed section 11 comprises the following structural elements:

engaging hole 9e as shown in Fig. 3A and 3B or an engaging hook provided to engaging tab 9a ; and
either one of engaging section 8a shaped like a snap for a non-return purpose provided to an inner wall of engagement stopper hole 8b or a rear open edge of stopper hole 8b for being elastically engaged with engaging hole 9e or the engaging hook.

lid cover

lid unit

Lid unit 8 includes lid frame 20 which comprises front frame 21 and rear frame 22 made of synthetic resin, and transparent window-board 23 made of transparent synthetic resin and sandwiched between front frame 21 and rear frame 22. Front frame 21 and rear frame 22 confront each other with transparent window-board 23 sandwiched in between, thereby forming window 7.
Projecting wall 8d of lid unit 8 is provided to front frame 21, and the surrounding wall 9c extending around the outer wall of lid unit 8 is generally flush with the outer surface of projecting wall 8d. Rear frame 22 includes flange 22a facing outward at its front end for being fitted to front frame 21. Flange 22a is mated with step 21a at rear inside of projecting wall 8d. This structure allows lid frame 20 to be integrated to one unit with front frame 21 and rear frame 22. In this case, front frame 21 is elastically engaged with lid cover 9, and these two elements can be handled as one single member, or rear frame 22 sandwiches window-board 23 with front frame 21, and these three elements can be handled as one single member. Then lid cover 9 is fitted to front frame 21 for elastically engaging with each other, and they can be fixed to each other. On top of that, surrounding wall 9c of lid cover 9 is generally flush with the outer face of projecting wall 8d, so that outer surface 9f of lid cover 9 extends to a wider area including a three-dimensional region and is simplified. Rear frame 22 includes flange 22a facing outward at its front end for fitting to front frame 21. Flange 22a is mated with step 21a inside the rear end of projecting wall 8d. An outer wall of rear frame 22 is thus located inside the outer walls of lid cover 9 and front frame 21, so that a region viewed from the outside, with lid cover 9 closed, gives a less thick image to the users.
Surface in parts 9b, placed on lid cover 9 correspondingly to at least fixed sections 11, are modified in their shape for the light from the inside to be refracted or dispersed when the light transmits through lid cover 9. This modified surface-shape can be one of the following shapes: (1) An annular or an arc shaped wrinkle grooved in a radial direction as shown with broken-line arrow marks in Fig. 3A, (2) Annular or arc wavy form grooved in the radial direction as shown with solid-line arrow marks in Fig. 3A, or (3) rough surface with peaks and valleys formed thereon and extending in every direction. Use of one of the foregoing shapes on the surface in-parts 9b allows preventing the fixed section 11 including the engaging section 8a from being viewed from the outside because of the foregoing pattern which does not lose the transparence. Surface in-parts 9b should not undergo a finely embossing process in order not to lose the transparence. Thus for instance, the pattern of peaks and valleys extending in every direction should have a roughness greater than a knurled pattern.
The structure discussed above is further detailed hereinafter. As shown in Figs. 1 and 2, housing 4 of the washing machine includes uphill slant face 4a at the upper front, and round inlet/outlet 31 of laundry is formed on this slant face 4a. Lid 5 is hinged to inlet 31 to open or close inlet 31 and is roundly shaped like inlet 31. Front frame 21 of lid frame 20 is molded of, e.g. polypropylene, and rear frame 22 is molded of, e.g. polypropylene having greater resistance against chemicals than the other one. Window board 23 is made of, e.g. glass, and lid cover 9 is formed of, e.g. transparent ABS resin. Placement of positioning projection 41 allows identifying how to mount cover 9 to lid unit 8 with ease, so that no wrong mounting can be expected. This simple mounting of cover 9 to lid unit 8 can advantageously avoid wondering which way cover 9 should be mounted, thus cover 9 can be mounted free from flaws. A wider transparent area is obtained on lid cover 9 of lid 5, and yet, fixed section 11 including engaging section 8a, which engages cover 9 with lid unit 8 behind lid cover 9, is prevented from being viewed from the outside of drum washing machine 1 of which rotary drum is placed horizontally or slanting downward.
The drum washing machine of the present invention allows the user to watch the laundry through the transparent lid cover and window with the lid closed while washing water, rinsing water, or hydrating splash is prevented from leaking to the outside. On top of that, the transparent lid cover is fitted on the front face of the lid unit and elastically engaged with the lid unit, and yet, a structure desirably non-visible from the outside, such as the fixed section including the engaging section, is prevented from being viewed expressly from the outside.
To be more specific, the surface in parts of the lid cover correspond to at least respective fixed sections, and the surface in-parts are kept transparent although they are modified their surface-shape in order to allow refracting or dispersing the transmitting light reflected on the engaging section. This structure allows not losing the transparence or transparent image of the lid cover, and yet not reducing the transparent area, while the interior structure can be prevented from being viewed from the outside. As a result, the drum washing machine with a quality look is obtainable. No additional components or no additional manufacturing steps are needed for achieving this drum washing machine exhibiting the quality look, so that no additional manufacturing cost is expected. The surface in-parts corresponding at least to the respective fixed sections avoid using finely-embossed process, which incurs the loss in the transparence due to diffusion reflection, but employ a pattern of peaks and valleys which prevents the fixed section including the engaging section from being viewed from the outside. The foregoing pattern exhibits transparent image as well as a quality look, thereby providing the drum washing machine with decorative feeling and a fine appearance.
The drum washing machine of the present invention allows obtaining a wide transparent area on its lid cover behind which the engaging section elastically engages the lid cover with the lid unit, and yet, this engaging section can be prevented from being viewed expressly from the outside. The lid can be modified as discussed above free from additional cost. The drum washing machine is thus of use to the users because of its compactness and fine appearance.

Claims

A drum washing machine, in which a cylindrical rotary drum (2) having a bottom plate is placed in a water tub (3) such that the drum (2) is oriented from an open front toward a rear bottom with its rotary shaft kept horizontal or slanting downward, and in the drum washing machine (1), laundry is put into the drum (2) through a lid (5) provided to a front section of a housing (4) of the washing machine (1), and the drum (2) is driven with a motor (6), thereby carrying out at least one of the steps of washing, rinsing, or dehydrating, wherein, the lid (5) comprises:
a lid unit (8) having a transparent window (7) through which the laundry can be monitored externally; and

a transparent lid cover (9) fitted on a front face of the lid unit (8) for covering the lid unit (8),

wherein a plurality of engaging tabs (9a) projecting rearward and placed on a rear face of an outer periphery of the lid cover (9), characterized in that a plurality of engagement stopper holes (8b) provided to the lid unit (8) for receiving the engaging tabs (9a) and elastically engaging the engaging tabs (9a) with engaging sections (8a) provided to the lid unit (8) for preventing the engaging tabs (9a) from slipping off and fixing the lid cover (9) to the lid unit (8), form a plurality of fixed sections (11) of the lid unit (8) and the lid cover (9),

wherein surface in parts (9b) placed along the periphery of the lid cover (9) corresponding to at least one of the fixed sections (11) has a modified surface-shape which allows a light from inside of the washing machine (1) to be at least refracted or dispersed when the light transmits through the lid cover (9), and which prevents the fixed sections (11) including the engaging sections (8a) from being viewed from the outside without any additional components, wherein the modified surface shape is selected from (i) an annular or an arc shaped wrinkle grooved in a radial direction; (ii) annular or arc wavy form grooved in the radial direction; and (iii) rough surface with peaks and valleys formed thereon and extending in every direction.
The drum washing machine of claim 1, wherein the lid cover (9) has a surround wall (9c) extending and surrounding an outer periphery of the lid unit (8), and the engaging tab (9a) is integrally molded with an end face (9d) of the surrounding wall (9c), and
a projecting wall (8d), which projects outward and includes a step (8c), is integrally molded with the lid unit (8) and placed on the outer wall of the lid unit (8) such that the step (8c) confronts the end face (9d), and the engagement stopper hole (8b) extends through the projecting wall (8d) from front to rear of the projecting wall (8d).
The drum washing machine of claim 1 or claim 2, wherein the fixed section (11) includes:
an engaging hole (9e) or an engaging hook provided to the engaging tab (9a); and

a snap (8a) provided to an inner wall of the engagement stopper hole (8b) for being elastically engaged with one of the engaging hole (9e) or the engaging hook; and

a rear open edge of the engagement stopper hole (8b).
The drum washing machine of claim 3, wherein the lid unit (8) includes:
a front frame (21) and a rear frame (22) forming a lid frame (20); and

a transparent window board (23) sandwiched between the front frame (21) and the rear frame (22),

wherein the projecting wall (8d) is provided to the front frame (21), and an outer surface of the surrounding wall (9c) of the lid cover (9) is generally flush with an outer surface of the projecting wall (8d), and the rear frame (22) includes a flange (22a) facing outward at its front end for fitting to the front frame (21), and the flange (22a) facing outward is mated with a step (21 a) provided rear inside of the projecting wall (8d).