EP3019925A1

EP3019925A1 - Household appliance with an improved front panel rotary selector switch

Info

Publication number: EP3019925A1
Application number: EP13734762.1A
Authority: EP
Inventors: Ismail GERZELI; Celal Vatansever; Mehmet ALTUG; Kutay Edis
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2013-07-08
Filing date: 2013-07-08
Publication date: 2016-05-18
Also published as: WO2015003730A1

Abstract

The present invention relates to an electrical household appliance having a front panel (3) for providing information display means and operation control elements to set different operation settings of the appliance, the front panel (3) having a knob (1) in the form of a rotary selector switch, surrounded by an indication ring (2) having separate indication means (4) and being fixedly attached to a surface portion of the front panel (3). The knob (1) comprising a single illumination means (7) and being rotatably disposed in a knob opening (16) in the center of said indication ring (2), an inner section (5) delimited by said knob's (1) outer shell and in an interengaging relationship therewith such that rotation of the knob (1) affects rotation of the inner section (5).

Description

HOUSEHOLD APPLIANCE WITH AN IMPROVED FRONT PANEL ROTARY SELECTOR SWITCH

The present invention relates to a household appliance having an improved front panel rotary selector switch for selectively indicating a visual indication means. More specifically, the present invention pertains to a household appliance knob that is selectively illuminating indication symbols by means of a single illuminating element.
Front faces of household appliances usually comprise a control and information panel in the upper portion thereof; such an information panel typically enabling the user set different operation modes and get informed of the current operational status of the appliance. Such an information display and operation control panel generally involves illuminating elements placed behind transparent textual indications for visually indicating operational status of the household appliance.
Among others, a prominent patent disclosure in the technical field of the present invention may be referred to as DE 4222335 A1, disclosing a rotary switch with a central knob that carries an illuminated symbol. The central section is surrounded by a fixed ring carrying symbols that are illuminated dependent upon the selected position of the switch. A single light source is used to provide illumination for the symbols by means of inner and outer rings of optical material transmitting light from the source to the appropriate points.
The present invention provides an improved information display and operation control knob, surrounded by an indication ring having a plurality of indication means in the form of transparent textual materials assigned to different operational modes, each of the transparent textual materials being back-lit during rotation of said knob.
The knob arrangement of the invention is advantageous in that a single light source is used for selectively illuminating only a certain visual indication means each time, without illuminating any closely neighboring indication means, which might be the case if optical materials that transmit light were to be used. This is achieved by means of special light guides that deliver light to a target area with a structural efficiency.
The present invention provides a knob with a single light source overcoming the aforementioned inconveniences, which is defined in the characterized portion of Claim 1.
Primary object of the present invention is to provide a knob with a single light source for selectively illuminating only a certain visual indication means each time, without illuminating any closely neighboring indication means.
The present invention proposes a household appliance having a front panel with a knob. An indication ring around the knob is fixedly attached to the front panel. A single illumination means illuminates peripherally different parts of said indication ring while said knob is rotated.
Said knob further has an inner section connected to itself, the inner section carrying the illumination means on its rear surface that is facing away from the knob. The illumination means a carried by a light guide holder that is also holding a light guide. The light guide is a hollow or solid tubular body that provides a light passageway from the illumination means to an indication means of the indication ring so as to illuminate the same from behind.
Said light guide has an outer surface fully coated with dark color to block the internal light and a reflective inner surface. The light guide may have a first part fixedly attached to the inner section to be cooperating with a separate, stationary second part.
Accompanying drawings are given solely for the purpose of exemplifying a household appliance front panel knob whose advantages over prior art were outlined above and will be explained hereinafter in brief.
The drawings are not meant to delimit the scope of protection as identified in the claims nor should they be referred to alone in an effort to interpret the scope identified in said claims without recourse to the technical disclosure in the description of the present invention.
Fig. 1 demonstrates a general perspective view of a household appliance front panel with an operation control knob according to the present invention.
Fig. 2 demonstrates a general perspective view of disassembled parts of an operation control knob according to a first embodiment of the present invention.
Fig. 3 demonstrates a cross-sectional view taken along the plane of the front panel according to the first embodiment of the present invention.
Fig. 4 demonstrates a general perspective view of the operation control knob where the inner section of the knob is placed into the knob opening according to a second embodiment of the present invention.
Referring now to the figures outlined above, the present invention proposes a household appliance front panel as defined in Claim 1.
The following numerals are assigned to different parts demonstrated in the drawings:

Knob
Indication ring
Front panel
Indication means
Inner section
Light guide
Illumination means
Inner section wings
Axial fixing means
Rotary selector switch shaft
Light guide holder
Electronic circuit
Electric conductor
Multiple-end light guide device
Light element driving circuit
Knob opening

The present invention proposes a household appliance such as a cooking oven or a laundry treatment appliance having a front panel (3) for providing various information display means and operation control elements to set different operation settings of the appliance.
The front panel (3) conventionally comprises a rotary selector switch, i.e. a knob (1) surrounded by an indication ring (2), the latter being fixedly attached to a front panel (3) surface in the center of which said knob (1) is rotatably disposed. Rotation of the knob (1) typically provides that a separate indication means (4) on the indication ring (2) is pointed out in an illuminated manner and an associated setting is selected. The front panel (3) in which the rotary selector switch is embedded is in the form of a substantially planar surface with a knob opening (16) being surrounded by said indication ring (2) which extends on the same plane with said front panel (3).
The knob (1) according to the present invention has an inner section (5) under the outer shell of the knob (1), said inner section (5) having a body with extensions in the form of radial wings (8) around an axial hole receiving a rotary selector switch shaft (10). A plurality of axial fixing means (9) engages with respective slots around the axial hole to restrict axial displacement of the inner section (5), which is in turn fixedly connected with the knob’s (1) outer shell in a suitable manner so that the two rotate together.
The present invention proposes a single illumination means (7), preferably in the form of a LED driven by a light element driving circuit (15), connected to an electronic circuit (12) by means of an electric conductor (13). The illumination means (7) is secured to the rear surface of the inner section (5) by means of a light guide holder (11), said rear surface facing away from the knob (1) and facing said knob opening (16).
Said light guide holder (11) lies in parallel with the surface normal axis of the front panel (3) and extends in the direction into said knob opening (16). As the indication ring (2) enclosing the knob (1) is substantially coplanar with the front panel (3) surface, an L-shaped light guide (6) structure is designed to illuminate the indication means (4) in the indication ring (2).
The light from said illumination means (7) that is also secured to the light guide holder (11) is delivered to each indication means (4) of the indication ring (2) from behind so as to provide a back-lit indication means (4) in the form of a visually discernible textual material around the knob (1). As the light guide (6) is secured to the rear surface of the inner section (5) of the knob (1), rotation of the knob (1) will displace the outer end of the light guide (6) between different positions corresponding to different indication means (4) to be juxtaposed therewith from behind.
According to the second embodiment of the present invention, the light guide (6) can be designed in the form of light guide (6) having a first part that is rotatably cooperating with a stationary second part. Said second part in the form of a multiple-end light guide device (14) has inner ends or openings reciprocating with said first part such that while the knob (1) is being rotated, a different indication means (4) is illuminated in response thereto.
This configuration is advantageous in that only a smaller and more compact body, that is the first part, remains in rotation together with said inner section (5) and with said knob (1) so that a simpler, mechanically more stationary and reliable structure is obtained. This second embodiment according to the present invention is shown in Fig. 4
The L-shaped structure of the light guide (6) according to the invention provides that an indirect and therefore diminished illumination effect is obtained within the light guide (6) so that illumination of any closely neighboring indication means (4) is avoided. A linearly extending light guide (6) can, however, be useful for applications where non-localized or scattered illumination is preferred.
In an embodiment of the present invention, the outer surface of light guide (6) is painted a dark and bright color to prevent undesired reflections inside the light guide (6).
In a nutshell, the present invention provides an electrical household appliance having a front panel (3) with a knob (1) surrounded by an indication ring (2). Said indication ring (2) has separate indication means (4) and is fixedly attached to a surface portion of the front panel (3). The knob (1) comprises a single illumination means (7) and is rotatably disposed in a knob opening (16) in the center of said indication ring (2).
The knob (1) further comprises an inner section (5) delimited by said knob’s (1) outer shell and in an interengaging relationship therewith such that rotation of the knob (1) affects rotation of said inner section (5). Said illumination means (7) is secured to a rear surface portion of the inner section (5) facing said knob opening (16) by means of a light guide holder (11) holding a light guide (6) in the form of a hollow or solid tubular body that delivers light from the illumination means (7) to an indication means (4) of the indication ring (2) from behind.
According to the present invention, while the outer surface of the light guide (6) is fully coated with dark color, the inner surface thereof has a reflective surface character. The present invention therefore provides that only a single light source provides selective illumination of a specific visual indication means in a distinctive manner without illuminating any closely neighboring indication means.

Claims

An electrical household appliance having a front panel (3) for providing information display means and operation control elements to set different operation settings of the appliance, said front panel (3) having a knob (1) in the form of a rotary selector switch, surrounded by an indication ring (2) having separate indication means (4) and being fixedly attached to a surface portion of the front panel (3), said knob (1) comprising a single illumination means (7) and being rotatably disposed in a knob opening (16) in the center of said indication ring (2), said knob (1) further comprising an inner section (5) delimited by the knob’s (1) outer shell and in an interengaging relationship therewith such that rotation of the knob (1) affects rotation of said inner section (5), characterized in that said illumination means (7) is secured to a rear surface portion of the inner section (5) facing the knob opening (16) by means of a light guide holder (11) holding a light guide (6) in the form of a hollow or solid tubular body that delivers light from the illumination means (7) to an indication means (4) of the indication ring (2) from behind.
The electrical household appliance as in Claim 1, characterized in that the light guide holder (11) extends in the direction into the knob opening (16).
The electrical household appliance as in Claim 1 or 2, characterized in that the light guide (6) has an outer surface fully coated with dark color and a reflective inner surface.
The electrical household appliance as in Claim 2 or 3, characterized in that the light guide (6) has an L-shaped structure.
The electrical household appliance as in Claim 1, 3 or 4, characterized in that the light guide (6) is in the form of a first part that is rotatable together with the inner section (5) to be cooperating with a stationary second part, said second part delivering light from the illumination means (7) to the indication means (4) of the indication ring (2) from behind.
The electrical household appliance as in Claim 5, characterized in that the second part is in the form of a multiple-end light guide device (14) having inner ends reciprocating with the first part such that while the knob (1) is being rotated, a different indication means (4) is illuminated in response thereto.
The electrical household appliance as in any one of the preceding claims, characterized in that the outer surface of light guide (6) is painted a bright-dark color.