Improved actuator device for household electrical appliances, in particular cooking hobs, electric ovens, microwave ovens, combination ovens or the like

Abstract: An actuator device for a household electrical appliance, in particular a cooking hob, electric oven, gas oven, microwave oven, combination oven or the like, comprises a knob (2) cooperating with a shaft (3) operationally connected to a usual actuator (4) for operating the household electrical appliance or a member thereof, said knob (2) being positioned on a control panel (5). The knob can be moved perpendicular to the control panel (5) along the longitudinal axis of the actuator shaft (3), the knob (2) being able to be distanced from the control panel (5) and moved out of the usual position in which it enables the appliance or its said member to be operated, means (15; 33, 34; 51) being associated with the shaft (3) to enable the actuator (4) to be operated even with the knob (2) in the position distanced from the control panel (5).

Description: This invention relates to a device as described in the introduction to the main claim. DE-U-9 114 215 discloses a medical electrical instrument comprising a knob having a grip portion. Such portion can be completely removed from the instrument for sterilisation purposes. As is well known it is possible that during the operation of a household electrical appliance, the knob by which the user operates it may become separated from its control panel with the consequent impossibility of altering the operation of the appliance or of a part or member thereof. This can cause obvious problems. Consider for example the action of a young child who while playing removes (with relative force) a knob which operates one of the heating elements of a cooking hob of gas burner type. It is then no longer possible to adjust the burner associated with this knob, so making it impossible to turn off the gas to the burner when required. With particular but not exclusive reference to a cooking hob or oven provided with any type of heating member, this action by the child can result in serious problems. In addition, in a cooking hob it is often necessary to clean the hob. This is suitably achieved by removing the usual knobs present on the hob control panel from the respective actuator shafts. After this cleaning, if the knobs are not replaced on their shafts, for example by forgetfulness, it is no longer possible to use the hob or oven. An object of the invention is to provide a device of the stated type by which even if a knob has been removed from its usual position on the control panel, the state of operation of the household electrical appliance and in particular of a cooking hob or oven can still be adjusted. A further object is to provide a device of the stated type which allows adequate access to the control panel, for example for its cleaning, without making it impossible to operate the actuator of the appliance and in particular the heating element of the cooking hob or the like. A further object is to provide a device which enables the appliance and in particular a cooking hob to be used even if the knob has been removed from its usual position on the appliance control panel. These and further objects which will be apparent to the expert of the art are attained by a device as described in the characterising part of the main claim. The present invention will be more apparent from the accompanying drawing, which is provided by way of non-limiting example and in which: Figure 1 is a perspective top view of a first embodiment of the invention with the knob in a first position of use: Figure 2 is a view similar to that of Figure 1 but with the knob in a second position of use; Figure 3 is a section on the line 3-3 of Figure 1; Figure 4 is a section on the line 4-4 of Figure 2; With reference to Figures 1 to 4, a knob 2 positioned on a control panel 1 is connected to an actuator shaft 3 usually connected to an actuator 4 (for example for a solenoid valve in a gas pipe) for operating a household electrical appliance, and in particular a burner of a gas cooker hob. The knob 2 is located on the upper face 5A of the control panel 5 for the household electrical appliance concerned. This control panel comprises an aperture 6 for the passage of the shaft 3 which, as stated, connects the knob to the actuator 4, which is positioned on the lower face 5B of said control panel. A usual protection insert 7 is provided in the aperture 6. The actuator shaft 3 comprises a body 10 (of known semicircular cross-section) with an upper free end 11 on which the knob 2 is forced. In proximity to this end the knob 3 comprises an annular recess 13 for cooperating with an elastic ring 14 supported in any known manner by a tubular cylindrical element 15 associated with the knob 2 and movable telescopically relative to the shaft 3. The ring 14 is supported internally by the element 15. Finally, the recess 13 comprises (in relation to said figures) an upper wall 16 and a lower wall 17 which connect smoothly to the rest of the body 10 of the shaft 3. The element 15 is removably associated with the knob 2 and is partly inserted into a socket-shaped part 20 of this latter in which it is retained by a usual flat spring 21. Finally, the knob comprises a usual body 23 of known shape (cylindrical) to facilitate its gripping. During the use of the cooking hob the ring 14 of the element 15 is withdrawn from the recess 13 in the shaft 3 (see Figure 3). As the cross-section through the element 15 and through the socket part 20 is identical to the cross-section through the shaft 3 in known manner, on rotating the knob 2 the shaft 3 rotates to operate on the actuator 4, in order for example to adjust the gas burner corresponding to this actuator to the desired flame level. When it is desired to clean the face 5A of the control panel 5, the knob 2 is moved along an axis Z perpendicular to the control panel 5 and coinciding with the longitudinal axis of the shaft 3, until the ring 14 enters the recess 13. When this insertion takes place the movement of the knob along said axis Z ceases. The face 5A of the control panel 5 can hence also be cleaned below the knob 2. As the element 15 remains in contact with the shaft 3 and is consequently torsionally coupled to it, this latter can be moved even with the knob 2 in the position distant from the control panel 5. To completely remove the knob from the control panel 5, for example in order to carry out maintenance on the shaft 3, the ring 14 is forced out of the recess 13 by pulling the knob 2 upwards (with reference to said figures). This however can be achieved only with a relatively large force which for example only an adult can exert. This prevents the knob being able to be removed by a young child with the obvious resultant problems related for example to the loss of the knob and the impossibility of operating the actuator 4. The knob 2 is repositioned on the shaft 3 in its usual position of use (Figure 1) by the opposite procedure to that used for separating the two members. and hence deducible from the aforegoing description. The repositioning will therefore not be further described. It should however be noted that because of the form of the walls 16 and 17 of the recess 13 the force required for removing the knob from and returning it to the shaft 3 is not excessive for an adult.

Claims: An actuator device for a household electrical appliance, comprising a knob (2) torsionally cooperating with a shaft (3) operationally connected to an actuator (4) for operating the household electrical appliance or a member thereof, said knob (2) being positioned on a control panel (5) provided on the appliance and being able to be moved relative to the control panel (5) along an axis (Z) perpendicular to this latter and coinciding with the longitudinal axis of the actuator shaft (3), the knob (2) being able to be distanced from the control panel (5) and moved out of the usual position in which it enables the appliance or its said member to be operated, characterised in that tubular cylindrical means (15) movable telescopically along the actuator shaft (3) and associated with the knob (2) are provided, said means (15) supporting locking means (14) arranged to cooperate with counter-means (13) associated with said shaft (3) when the knob (2) is in its position distant from the control panel (5), said cooperation still maintaining the knob (2) torsionally associated with the actuator shaft (3). A device as claimed in claim 1, characterised in that the locking means are an elastic ring (14) associated with the interior of the tubular means (15), the counter-means being a recess (13) provided in proximity to that end (11) of the actuator shaft (3) on which the knob (2) is mounted. A device as claimed in claim 2, characterised in that said recess (13) is smoothly joined to the remaining parts of the body (10) of the actuator shaft (3). A device as claimed in claim 1, characterised in that the tubular cylindrical means are a tubular cylindrical element (15) which is torsionally rigid with the knob and is inserted into a socket-shaped part (20) of this latter, said element (15) being retained in this part by an elastic element (21).

Inventors: DISTASO ALESSANDRO, DISTASO, ALESSANDRO
Applicants: WHIRLPOOL EUROP, WHIRLPOOL EUROPE B.V.
Application year: 1993
Main classification: F24C3
IPC codes: G05G1, F24C7, F24C3