GB2102938A

GB2102938A - Vitreous ceramic cooker-hob

Info

Publication number: GB2102938A
Application number: GB8218800A
Authority: GB
Inventors: Herwig Scheidler
Original assignee: Carl Zeiss AG
Current assignee: Carl Zeiss AG
Priority date: 1981-07-01
Filing date: 1982-06-29
Publication date: 1983-02-09
Also published as: CH657442A5; GB2102938B; DE3126013A1; ATA252882A; AT383932B; DE3126013C2

Abstract

A vitreous ceramic cooker-hob comprising a hob panel (5) and a surrounding frame (7) adapted to be fitted in a worktop-cut-out (2) is connected with the housing (3) by means of snap-fit engagement as well as by means of a screw (15). The screw (15) is accessible when the hob panel is slightly raised from its flush-fitted position to thereby disengage the snap-fit connection but completely concealed in the latter position so as to provide a smooth flush surface and preclude the risk of incorrect removal of the hob panel by unskilled persons with the inherent danger of exposed electrical contacts. <IMAGE>

Description

SPECIFICATION Vitreous ceramic cooker-hob The invention relates to a vitreous ceramic cooker-hob of the kind comprising a hob-panel which is rigidly attached to a surrounding frame received in and adapted to be lifted out of a hobhousing fitted inside of worktop cut-out and secured in this position by a snap-fit engagement between the frame and the housing.

A vitreous ceramic cooker-hob of this kind is already known (German GM 77 18 108). The snap-fit engagement provided between the frame of the hob panel and the hob housing makes for easy assembly and, subject to the provision of adequately strong spring forces securing this snap fit engagement, it also satisfies standard electrotechnical safety requirements (VDE approval). If desired, the snap-fit can be released and the hob-panel can be lifted up to give access to the heating elements and other parts for maintenance or repair purposes without having to dismantle the entire hob assembly.In order to satisfy existing safety regulations, the effective spring forces must be relatively strong so as to ensure that the hob panel can only be removed with the aid of a tool; however, it cannot be ruled out that the hob panel section could be incorrectly removed by an unskilled person who fails to perceive the danger of exposed electrical contacts because of the absence of screw connections.

It is also already known, on the other hand, in vitreous ceramic cooker-hobs to secure the frame which is attached to the hob panel to the hob housing by means of screws so that the hob may be lifted out only after these screws have been undone with the aid of a suitable tool (German GM 77 18 108, Figure 7). In this arrangement, the screw-connection replaces the snap-fit mounting. The screws are threaded in from above through holes in a horizontal flange of the frame which overlaps the housing which is provided with threaded bushes and also overlaps the edge of the cut-out in the worktop. However, with this type of hob-panel mounting, the screw heads remain visible which impairs visual appearance and also creates an increased risk of dirt accretions in the region of the screw heads and of the sealing washers therebeneath.

Accordingly it is the aim of the present invention to design and execute the hob panel fastening or securing means in such a way that-whilst preserving the easy re-movability of the hob panel by lifting it up from the hob unit, this operation can be performed only with the aid of a tool thus affording substantially improved safety in regard to accidental touching of electrical parts and contacts without having to sacrifice the advantage of a flush surface finish which is obtained with a snap-fit mounting.

According to the present invention this aim is achieved by means of the characteristic provisions according to claim 1. Convenient embodiments and further developments may be observed from the subclaims.

According to the principle of this invention, therefore, the securing means comprise a screw fastener connection as well as a connection by virtue of snap-fit engagement, the arrangement being however such that the screw-connection still permits a limited degree of relative movement between frame and housing whilst the final operative position of the hob panel is only defined by ultimate snap-fit engagement. Due to this provision the hob panel can be raised only by a very small amount without undoing the screws just enough to give access to these screws, whereas on the other hand the screws are completely concealed in the operative position, i.e. when the snap-fit connection is engaged. As a bonus there is the further advantage that the spring forces are no longer required to be so very strong, which makes it still easier to lift the hobpanel section with frame off the housing.

Conveniently the fastener screws are arranged on the frontal and/or on the two lateral sides of the hob-panel. Depending on the construction of the spring elements in the snap-fit-connection, it may be sufficient to provide just one screw connection especially if a rotation mechanism is applied for dropping the hob-panel section into its correct place. It is however preferred to provide two fastener screws.

Four embodiments of the invention are hereinafter more particularly described by way of example, each with reference to one figure of the accompanying drawings representing a vertical section through the hob-housing and the hobpanel in a position in which the fastener screws are applicable, i.e. in the "screwing" position.

In all four embodiments a work-top 1 is provided with a cut-out 2 in which is fitted a hobpanel housing 3 which comprises a circumferentially continuous upper supporting flange 4 resting on the edge of the cut-out in the work-top 1.

There is further provided a hob-panel section 5 of vitreous ceramic material which, with interposition of an adhesive sealant 6, is bonded to a surrounding frame 7 which comprises a vertical web 8 with an inwardly directed flange 9 adapted to extend beneath the outer edge of the hob-panel 5, and an outwardly directed flange 10 which in the operatively fitted position overlaps flange 4 of housing 3 as well as the peripheral edge of the cut-out in the worktop 1, as will be seen on the left hand side offing. 1. In accordance with the state of the art (not shown in drawing) the cut-out in the work-top is also sealed against moisture penetration by a rubber seal or similar solution applied between work-top and the outer flange 4 of the hob housing and between the said outer housing flange 4 and the outer flange 10 of the frame.

There are further provided means for snap-fit engagement between housing 3 and frame 7, which are not shown in the drawings because they do not extend in the section plane. These snap-fit means come into effect only after the hob-panel 5 with its frame 7 has been dropped fully into the dished housing 3 so that the hobpanel 5 shown in Figure 1 with its right hand side lifted up, occupies a horizontal position-that is to say, the operative and snap-fit engagement position thereof.

It goes without saying that different frame profiles 7 may be used with polygonal as well as with round or oval cooker hobs 5.

According to Figure 1 a screw fastening 11 is provided between the housing 3 and the frame 7, which comprises a hinge 12 with securing tabs 13 and 14 hinged to both hinge strips thereof on the outwardly directed sides. The securing tab 13 is rigidly connected to housing 3 whereas securing tab 14 is detachably secured to the inside of web 8 of the frame 7 by means of a screw 15.

It will be observed from Figure 1 that in the screw-fastening position there shown with one side of the hob panel lifted, the screw 1 5 can be readily fitted and removed. After removal of screw 1 5 the panel 5 with its frame 7 can be completely taken off so that the housing 3 with all parts accommodated therein is readily accessible from above. Without releasing the screw 1 5 the hob panel 5 may be raised just a little bit further by extending the hinge 12, but the bottom end of the downwardly directed web 8 of frame 7 still remains inside housing 3 so that this remains always substantially closed off for as long as the screw 1 5 is not removed.Furthermore, the hob panel 5 may be dropped completely from the illustrated position in which the fastener screw is secured, into the cut-out 2 or into the hob housing 3 by folding the hinge 12, which brings the screw 1 5 into an inaccessible position within housing 3 and entails the effective engagement of the snap-fit means, not shown, which secure this operative position of the assembly.

In the embodiment according to Figure 2 a screw connection 21 is provided between housing 3 and frame 7 which comprises a pivotable element 22 which is located by means of a screw 23 on housing 3 with a certain amount of play and which is connected by means of a further screw 25 to the frame 7. As shown in this figure, in this arrangement the hob panel 5 can be lifted as a whole in horizontal alignment into the screw-fastening position shown in the drawing in which the screw 25 is accessible.

In the embodiment according to Figure 3 the screw-fastening means comprise a flexible metal strip 32 having one end fastened to housing 3 and the other connected by means of a screw 35 to the frame 7. The flexible metal strip 32 works in the same way as the hinge 12 shown in Figure 1.

According to Figure 4 a screw-fastening 41 is provided which comprises a flexible wire-mesh strap 42 having one end fixed to housing 3 and the other fastened to frame 7 by means of the screw 45.

Again the wire-mesh strap 42 corresponds functionally to the hinge 12 shown in Figure 1 or to the flexible metal strip 32 according to Figure 3. In the same way as the latter it provides a safe electrical earthing connection between frame 7 and housing 3.

It was found that it may be quite enough to lift the hob panel 5 as a whole or only along that side thereof on which the screw fastenings 11, 31, 41 are arranged by a mere 5 mm to make the normally concealed screws 15, 25, 35, 45 accessible. However, for preference the removable screw is raised by a distance of about 10 to 25 mm into the accessible position. With such a short lifting distance the connecting elements 12, 22, 32, 42 of the screw fastening device 11, 21, 31, 41 are also relatively short and less expensive.

Claims

1. A vitreous ceramic cooker-hob comprising a hob-panel which is rigidly attached to a surrounding frame received in and adapted to be lifted out of a hob-housing fitted inside a worktopcut-out, and secured in this position by snap-fit engagement between the frame and the housing wherein, in addition to the snap-fit connection, there is provided at least one screw-fastening connection between the frame and the housing which limits raising of the hob panel relative to the housing and is so designed and arranged that the hob panel, when being fitted and prior to achieving snap-fit engagement, occupies a screwfitting position in which the fastener screw can be fitted; wherein the screw connection permits relative movement of the frame and the housing between the said screwfitting position and snapfit position; and wherein the fastener screw is inaccessible in the snap-fit position.

2. A vitreous ceramic cooker-hob according to Claim 1 wherein the screw-fitting position is so close to the snap-fit position that the frame with the hob panel already form an effective cover to close off the housing in the said screw-fitting position.

3. A vitreous ceramic cooker-hob according to Claim 1 or 2, wherein the screw-connection comprises a connecting element which is secured to the housing and connected by means of the screw to the frame.

4. A vitreous ceramic cooker-hob according to claim 3 wherein the connecting element is a hinge.

5. A vitreous ceramic cooker-hob according to Claim 3 wherein the connecting element is a pivotable construction part.

6. A vitreous ceramic cooker-hob according to Claim 3 wherein the connecting element is a flexible metal strip.

7. A vitreous ceramic cooker-hob according to Claim 3 wherein the connecting element is a strap of wire mesh.

8. A vitreous ceramic cooker-hob according to any of Claims 1 to 7, wherein the screw-fastening connection provides an earth connection between the frame and the housing.

9. A vitreous ceramic cooker-hob according to any of Claims 1 to 7, substantially as hereinbefore described in Figure 1 or Figure 2 or Figure 3 or Figure 4 of the accompanying drawings.