Retractable rotary control knob with a marker ring

Abstract

 The retractable rotary knob (1) for controlling power on a domestic stove, normally recessed in the stove control panel and projected for switching operations, comprises a marker ring (2) indicating the setting numbers (3) of the control knob (1), made of semi-rigid plastic in form of a strip, which clamps a peripheral body (6) of the knob The setting numbers (3) visible from above are impressed on said ring (2) which is fitted on said body (6) between two emerging ridges (13,14) by means of two retaining hooks to engage into corresponding openings on the body (6) wall. The marker ring has a gap in its perimeter for its diametral expansion. Interchangeability is facilitated by two enlarged ends which are pressed to release the ring from the knob.

Description

[0001] The present invention relates to a retractable rotary control knob incorporating a marker ring indicating the position of rotation of said control knob for use in domestic stoves with an oven and electrical or gas top cooker.

PRIOR ART

[0002] At present, the setting sector with the markings of the different power switching positions of each control on stoves with this retractable control knob consists of a disc installed on the front and connected to the control shaft inside the control panel, though not incorporated on to it. The reading is from a transparent display on the panel covering said disc. Stove control panels are usually above the oven and below the top cooking surface, and are built into the unit at the time of manufacture.

[0003] The person installing the apparatus in a home has a plurality of different disc-shaped dials, one of which is fitted for each knob depending on the type of top cooker or oven with which the stove is equipped. Said known retractable knob with which the disc-dial located inside the front control panel is associated has the drawback that the person installing the apparatus has first to dismantle the panel in order to replace the previously installed dials with those for the top cooker fitted, so as to customize the control panel.

[0004] DE-2701017-C2 describes a retractable rotary control knob wherein a marker ring is attached to the barrel of the knob. This marker ring is integral part of the barrel, forming a sloping shoulder on which are engraved the knob position numbers, it is not interchangeable and it is expensive.

DISCLOSURE OF THE INVENTION

[0005] The object of the invention is a retractable rotary control knob with a marker ring incorporated to indicate the rotatory knob switching position, for the control of electrical or gas stoves, wherein the marker ring is interchangeable and made of semi-rigid plastic in the form of a strip, the cross-section of which is flat and thin and its circular perimeter is cut for elastic expansion, in order to couple it on to and around the cylindrical body of the knob.

[0006] Means are provided for retaining the marker ring on the knob body, thus the marker ring has a retaining hook on the back on each side of its expansion gap and the knob body has the corresponding opening through its wall, the marker ring being incorporated to the knob, recessed with it into the control panel and remaining visible when the knob is pulled out for the selection or switching operation.

[0007] When unexpanded, the diameter of the marker ring is adjusted to that of the cylindrical body of the knob, surrounding it and tightened by the force provided by the elasticity of the ring material itself. To fit on to the knob body, the perimetral gap is opened until the knob diameter can fit into it and said retaining hooks are then placed in their openings on the periphery of the knob body.

[0008] The ring with the position numbers is read from above, in a more comfortable position for the user, the construction of the marker ring is simple and made by moulding, and it is easily to assemble by the user himself without removing the control panel, by bringing both enlarged ring ends and then disengaging the retaining hooks.

DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a plan view of the retractable rotary knob with a marker ring object of the invention.

[0010] FIG. 2 is a plan view of the retractable rotary knob in figure 1, without the marker ring.

[0011] FIG. 3 is a lengthwise cross-section of the retractable rotary knob along II-II in figure 2.

[0012] FIG. 4 is a transverse cross-section of the retractable rotary knob along III-III in figure 2.

[0013] FIG. 5 is a profile view of the marker ring for the retractable knob in figure 1.

[0014] FIG. 6 is a cross-section of the marker ring along V-V in figure 5.

PREFERRED EMBODIMENT OF THE INVENTION

[0015] Figures 1 - 6 show a preferred embodiment of the retractable knob 1 incorporating the marker ring 2 object of the invention, and of its particular elements. The body 6 of the retractable rotary knob 1 is of known configuration, and is for use on a stove with an oven and an electrical or gas top cooker, and modified to incorporate the marker ring 2 which is in form of a strip of flat section and made of semi-rigid plastic by moulding, such as PET which is heat-resistant and has the switch setting numbers 3 impressed on its surface.

[0016] The marker ring 2 as shown in figures 5 and 6 has a gap 4 on its perimeter, the width 5 of which expands elastically to exceed the diameter 7 of the body 6, so as to fit it to the body surface by means of the parallel hooks 8 that emerge close to each end 9 of the marker ring 2, on the sides of the gap 4.

[0017] To facilitate the expansion of the marker ring 2, the ends 9 are radially enlarged to provide a grip surface to separate them. The diameter 10 of the marker ring 2 when not expanded adjusts to the diameter 7 of the cylindrical body 6 of the rotary knob 1 so that, by elastic force, the marker ring 2 enters into pressure contact with the body 6 surface so as to remain firmly secured to it. The hooks 8 for holding the marker ring 2 are not attached to the body 6 but are rather inserted in their openings 11 in the inside hollow 12 of the body 6. Said openings 11 have a degree of play in relation to the thickness of the securing hooks 8.

[0018] To make it easier to insert the ring retaining hooks 8, the openings 11 in the body 6 of the control knob are U-shaped as shown in figures 2 and 3, forming a flange 11' which goes down under the hook pressure.

[0019] The marker ring 2 is incorporated clamped on to the cylindrical body 6 of the rotary knob, fitted on a external body housing 6' between two emerging annular ridges 13 and 14, and placed flush with the inside edges of said ridges 13 and 14, the ring 2 appearing to be a part of the knob body 6.

Claims

1. A retractable rotary control knob with a marker ring for control of domestic electrical or gas stoves, wherein the marker ring (2) is incorporated into the cylindrical body (6) of the knob (1) with the setting numbers (3) seen from above and recessed with the knob into the inside of the stove control panel, characterized in that the marker ring (2) is interchangeable and it is constructed in the form of a strip and fitted between two annular ridges (13, 14) which emerge from the periphery of the knob body (6), and for interchanging it has a perimetral gap (4), the width (5) of which (5) expands elastically, and retaining means (8,9) are provided which are disengageable.

2. A retractable rotary control knob with a marker ring according to claim 1, wherein said retaining means (8,9) comprise a retaining hook (8) on each side of said gap (4) of the marker ring (2) and a corresponding opening (11) U-shaped (11) in the knob body (6) wall, and the ends (9) of the marker ring are enlarged to make easier the gap (4) expansion.

Drawing