Telescopic slide for a microwave oven

Abstract

A telescopic slide for a microwave oven has a first slide element and a second slide element each having two running surfaces with caged rolling bodies arranged on the running surfaces. The slide elements can be moved along against each other between a retracted position and an extended position. The slide elements each have at least one electrically conductive contact element arranged on the slide elements in such a way that in the retracted position either the contact elements are directly in engagement or that the contact element of the first slide element and the contact element of the second slide element are each in engagement with an electrically conducting conductive element that is moved concomitantly with the rolling-body cage. The result is that in the retracted position there is an electrically conducting connection between the first and the second slide elements, and in at least one position other than the retracted position the electrically conducting connection is broken.

Claims

1. Telescopic slide (2, 2′) for a microwave oven (1) with at least one first slide element (5, 5′) made of an electrically conductive material and a second slide element (6, 6′) made of an electrically conductive material, wherein the first and the second slide elements (5, 5′, 6, 6′) each have two running surfaces, wherein rolling bodies (29) accommodated in a rolling-body cage (26, 27) are arranged on the two running surfaces of the first slide element (5, 5′) and rolling bodies (29) accommodated in a rolling-body cage (26, 27) are arranged on the two running surfaces of the second slide element (6, 6′), and wherein the first and the second slide elements (5, 5′, 6, 6′) can be moved against each other between a retracted position and an extended position in an extension direction (10), characterized in that the first slide element (5, 5′) has at least one electrically conductive contact element (18, 22) and the second slide element (6, 6′) has at least one electrically conductive contact element (19, 23), wherein the contact element (18, 22) of the first slide element (5, 5′) and the contact element (19, 23) of the second slide element (6, 6′) are designed and arranged on the slide elements (5, 5′, 6, 6′) in such a way that in the retracted position either the contact element (18) of the first slide element (5) and the contact element (19) of the second slide element (6) are in engagement with each other or the contact element (22) of the first slide element (5′) and the contact element (23) of the second slide element (6′) are each in engagement with an electrically conducting conductive element that is moved concomitantly with the rolling-body cage (26), with the result that in the retracted position there is an electrically conducting connection between the first and the second slide elements (5, 5′, 6, 6′) and in at least one position other than the retracted position the contact element (18) of the first slide element (5) and the contact element (19) of the second slide element (6) are not in engagement with each other or at least the contact element (22) of the first slide element (5′) or the contact element (23) of the second slide element (6′) is not in engagement with the conductive element, with the result that in the at least one other position the electrically conducting connection is broken, wherein at least the first slide element (5, 5′) or the second slide element (6, 6′) has two limbs (12, 13), which limbs form the running surfaces of the rolling bodies (29), and wherein the first slide element (5, 5′) and the second slide element (6, 6′) each have a connecting portion (14, 15) connecting the two limbs (12, 13), wherein the contact elements (18, 19) of the first slide element (5, 5′) and the contact elements (22, 23) of the second slide element (6, 6′) are each arranged on the connecting portions (14, 15).

2. Telescopic slide (2, 2′) according to claim 1, characterized in that at least one of the contact elements (18, 19, 22, 23, 24, 25) is formed by a protrusion on the first or second slide element (5, 5′, 6, 6′).

3. Telescopic slide (2, 2′) according to claim 2, characterized in that at least one protrusion (18) has a greater extent in the extension direction (10) than in a direction perpendicular to the extension direction (10).

4. Telescopic slide (2, 2′) according to claim 2, characterized in that the protrusion is formed as a stamping (16, 17) of a sheet material of the respective slide element (5, 6).

5. Telescopic slide (2, 2′) according to claim 1, characterized in that the contact element of the first slide element (5) is formed by a protrusion (18) and the contact element of the second slide element (6) is formed by a protrusion (19), wherein the protrusion (18) on the first slide element (5) has a greater extent in the extension direction (10) than in a direction perpendicular to the extension direction (10), and wherein the protrusion (19) on the second slide element (6) has a smaller extent in the extension direction (10) than in the direction perpendicular to the extension direction (10).

6. Telescopic slide (2, 2′) according to claim 5, characterized in that it has two outer slide elements (5, 7) and a middle slide element (6), wherein the protrusion (19) with the extent that is greater in the extension direction (10) than the extent in the direction perpendicular to the extension direction (10) is provided on the middle slide element (6).

7. Telescopic slide (2, 2′) according to claim 1, characterized in that the contact elements (18, 19, 22, 23, 24, 25) are in engagement with each other or are both in engagement with the conductive element exclusively in the retracted position.

8. Telescopic slide (2, 2′) according to claim 1, characterized in that the contact elements (18, 19) are in engagement with each other or are both in engagement with the conductive element in the retracted position and in the extended position (10), starting from the retracted position, over a range of positions outside the retracted position, wherein the length of the region in the extension direction (10) is predetermined by an extent and/or a position of the contact elements (18, 19) on the slide elements (5, 6) in the extension direction (10).

9. Telescopic slide (2, 2′) according to claim 1, characterized in that the contact element (18) of the first slide element (5) and the contact element (19) of the second slide element (6) are arranged and designed in such a way that in the retracted position the position of the engagement between the contact element (18) of the first slide element (5) and the contact element (19) of the second slide element (6) in the extension direction (10) lies in a region in which the ball cage is located.

10. Telescopic slide (2, 2′) according to claim 1, characterized in that the telescopic slide (2, 2′) has two outer slide elements (5, 7) and a middle slide element (6) arranged between the two outer slide elements (5, 7), wherein the two outer slide elements (5, 7) each have at least one contact element (18) and the middle slide element (6) has at least two contact elements (19), with the result that in the retracted position either a contact element (18) of each outer slide element (5, 7) is in each case in engagement with a contact element (19) of the middle slide element (6) or a contact element of an outer slide element and a contact element of the middle slide element are in each case in engagement with an electrically conducting conductive element that is moved concomitantly with a rolling-body cage, with the result that in the retracted position there is an electrically conducting connection between the outer slide elements and the middle slide element.

11. Telescopic slide (2, 2′) according to claim 1, characterized in that at least the first or the second slide element (5, 6), at an end (8, 9) thereof, has an insulation (28), which is designed in such a way that in the retracted position it is arranged in a possible spark gap between the first and the second slide element (5, 6).

12. Telescopic slide (2, 2′) according to claim 1, characterized in that the conductive element is a portion of the rolling-body cage.

13. Microwave oven (1) with a telescopic slide (2, 2′) according to claim 1.

14. Microwave oven (1) according to claim 13, characterized in that the microwave oven (1) has an oven muffle (4) and a door (11, 11′) for closing the oven muffle (4), wherein the telescopic slide (2, 2′) is built into the oven muffle (4) in such a way that, when the door (11, 11′) is in a position that releases the oven muffle (4), the first slide element (5, 5′) or the second slide element (6, 6′) can be brought into the extended position, with the result that the first slide element (5, 5′) or the second slide element (6, 6′) protrudes out of the oven muffle (4), and wherein at least one length of the first slide element (5, 5′) or one length of the second slide element (6, 6′) in the extension direction (10) is selected in such a way and the contact element (18) of the first slide element (5) and the contact element (19) of the second slide element (6) are arranged and designed in such a way that, when the door (11, 11′) is in a position that closes the oven muffle (4), inevitably the contact element (18) of the first slide element (5) and the contact element (19) of the second slide element (6) are in engagement with each other or the contact element (22) of the first slide element (5′) and the contact element (23) of the second slide element (6′) are each in engagement with the electrically conducting conductive element that is moved concomitantly with the rolling-body cage (26), with the result that there is an electrically conducting connection between the first and the second slide elements (5, 5′, 6, 6′).

Description

(1) In a further embodiment, the elastic part is dimensioned in such a way that, when the door is in the position that closes the oven muffle, it is in engagement with the door and the telescopic slide. In particular, in an embodiment, the part is then elastically deformed. Further advantages, features and possible applications of the present invention will become apparent from the following description of an embodiment and the associated figures.

(2) FIG. 1 is a schematic top view of a microwave oven according to an embodiment of the present invention.

(3) FIG. 2 is a perspective, broken-open view of an embodiment of the telescopic slide according to the invention.

(4) FIG. 3 is a schematic cross-sectional view of an alternative embodiment of the telescopic slide according to the invention.

(5) In the figures, elements that are the same are given the same reference numbers.

(6) FIG. 1 shows a microwave oven 1 with two telescopic slides 2 according to the invention, which are each connected to a side wall 3 of the muffle 4 of the oven 1. The telescopic slides 2 are full extension slides with three slide elements 5, 6, 7.

(7) During operation of the microwave oven 1 the telescopic slides 2, but in particular the inner slide elements 5, are exposed to the microwave radiation of the oven. This electromagnetic radiation results in a local electrostatic charge in the slide elements 5. This charge can, in turn, result in sparkovers in the region of the ends 8, 9 of the slide elements 5, 6, 7.

(8) In addition, arranged between the slide elements 5, 6, 7 of the telescopic slides 2 are ball cages with ball bearings (not shown in FIG. 1) arranged therein, which serve to guide the individual slide elements 5, 6, 7 relative to each other. The electrostatic charge of the slide elements 5, 6, 7 can also result in currents discharging across the ball bearings. Owing to the punctiform physical contact of the ball bearings with the running surfaces of the slide elements 5, 6, 7, high currents can be produced, which result in damage, either to the balls or to the running surfaces.

(9) In order to prevent the local electrostatic charge, in particular of the slide element 5, the telescopic slides 2 each provide an electrically conducting connection at the three positions identified by arrows along the extension direction 10 of the telescopic slide 2.

(10) When the door 11′ is in an open position, the slide elements 5, 6 can be drawn out through the opening of the muffle 4.

(11) However, the microwave oven 1 can only be put into operation when the door 11 is closed. In other words, an electrostatic charging of the slide elements 5 can only ever occur when the door 11 is closed. It therefore suffices if the potential equalization is only possible in the represented retracted position of the telescopic slides 2.

(12) In the embodiment shown in FIG. 1, therefore, the lengths of the slide elements 5, 6, 7 in the extension direction 10 are dimensioned such that, when the door 11 is closed, the slide elements are substantially in the retracted position. Furthermore, the contact elements of the first slide element 5 and the contact elements of the second slide element 6 are arranged and designed in such a way that, when the door 11 is in the closed state, the contact elements of the first slide element 5 and the contact elements of the second slide element 6 are inevitably in engagement with each other, with the result that there is an electrically conducting connection between the first and the second slide elements 5, 6.

(13) In order to be able to compensate the comparatively long tolerance chain, consisting of the tolerances of the door 11, 11′ and its fastening, the muffle 4 and the telescopic slides and their assembly, a shaped silicone part 30 is arranged at the end 9 of the first, inner slide element 5 facing towards the opening of the muffle 4. When the door 11 is in the closed state, this shaped silicone part extends between the door 11 and the end 9 of the inner slide element 5. The shaped silicone part 30 here is dimensioned such that it is in engagement with the door 11 and if necessary is elastically deformed by the latter.

(14) FIG. 2 shows a broken-open, perspective view of the telescopic slide 2 from FIG. 1. It can be clearly seen that the telescopic slide 2 has two outer slide elements 5, 7 and a middle slide element 6, which together form a full extension slide. In the retracted position, which is also represented in FIG. 2, the outer slide element 5 and the middle slide element 6 are connected to each other in an electrically conducting manner. Here, within the meaning of the present application, the outer slide element 5 forms a first slide element and the middle slide element 6 forms a second slide element.

(15) Each of the first and second slide elements 5, 6 has in each case two limbs 12, 13, wherein only one of the limbs 12, 13 of each slide element 5, 6 is shown in the representation from FIG. 2. The limbs 12, 13 here form the raceways for accommodating the ball bearings between the slide elements 5, 6, 7. The two limbs 12, 13 of a slide element are in turn connected to each other via connection portions 14, 15 of the slide elements 5, 6.

(16) In order now to provide the necessary potential equalization in the retracted position, the connection portions 14, 15 of both slide elements 5, 6 are provided with indentations or beads 16, 17. On the respectively other side of the sheet material of the slide elements 5, 6 these beads 16, 17 form protrusions 18, 19, which protrude relative to the surfaces 20, 21 of the connection portions 14, 15 of the slide elements 5, 6. These protrusions 18, 19 on the connection portions 14, 15 of the slide elements 5, 6 form contact elements within the meaning of the present application.

(17) The protrusions 18, 19 here are designed such that they are in mechanical engagement with each other only in the retracted position. If the slide elements 5, 6, 7 are extended, the protrusions 17, 18 are not in engagement. Only the mechanical engagement, however, provides an electrically conductive connection between the first slide element 5 and the second slide element 6.

(18) In the embodiment shown, the bead 16, and therefore the protrusion 18, on the first slide element 5 has an extent in the extension direction 10 of the telescopic slide 2 which is smaller than the extent of the bead 16, and therefore of the protrusion 18, in the direction perpendicular to the extension direction 10. In contrast, the bead 17, and therefore the protrusion 19, on the second slide element 6 has an extent in the extension direction 10 which is greater than the extent of this protrusion in the direction perpendicular to the extension direction 10.

(19) This crossed arrangement of the protrusions 17, 18 makes a certain compensation of the tolerances of the slide elements and of the assembly of the slide elements 5, 6, 7 possible. In particular, however, the extensive longitudinal extent in the extension direction 10 of the protrusions 19 makes an engagement possible between the protrusions 18, 19 over a region. The conductive connection between the protrusions 18, 19, as contact elements, is thus provided not only in the retracted position defined by the end stop but also in a region close to the retracted position.

(20) In addition, arranged at the end of the inner slide element 7 is an electrical insulator 28 which in the retracted position is located between the middle slide element 6 and the inner slide element 7. The insulator 28 thus lies in a possible spark gap between the middle slide element 6 and the inner slide element 7 and prevents a sparking between the slide elements 6, 7.

(21) In the embodiment of the telescopic slide 2 from FIG. 2, the electrically conductive connection between the first and the second slide elements 5, 6 is provided by a direct mechanical engagement between the two protrusions 18, 19 of the slide elements 5, 6. In contrast, the electrical connection of each two slide elements 5′, 6′ and 6′, 7′ is provided via the ball cages 26, 27 arranged between the contact elements 22, 23 and 24, 25 respectively.

(22) In this embodiment of a telescopic slide 2′ according to the invention, in the retracted position the contact elements 22, 23 are in engagement with the first ball cage 27 as a conductive element within the meaning of the present application. In the retracted position the contact elements 24, 25 are in engagement with the second ball cage 26.

(23) It is to be noted here that, in the embodiment represented, the engagement between the contact element 23 on the second slide element 6′ and the ball cage 27, on the one hand, and the engagement between the contact element 22 on the first slide element 5′ and the ball cage 27, on the other hand, is effected at different positions in a direction perpendicular to the extension direction 10. In this way, the spring property of the ball cage 27 can be utilized in order to ensure an improved electrical contact between the contact elements 22, 23 and the ball cage 27.

(24) For purposes of original disclosure, it is pointed out that all features, as revealed to a person skilled in the art from the present description, the drawings and the claims, even if they have specifically been described only in connection with particular further features, can be combined, both individually and in any combinations, with others of the features or feature groups disclosed here, unless this has been explicitly ruled out or unless technical circumstances make such combinations impossible or meaningless. Only, for reasons of the brevity and readability of the description, a comprehensive, explicit presentation of all conceivable feature combinations is dispensed with here.

(25) While the invention has been represented and described in detail in the drawings and the preceding description, this representation and description are merely exemplary and are not intended as a limitation of the scope of protection as defined by the claims. The invention is not limited to the disclosed embodiments.

(26) For a person skilled in the art, modifications of the disclosed embodiments are obvious from the drawings, the description and the attached claims. In the claims the word “have” does not rule out other elements or steps, and the indefinite article “a” or “an” does not rule out a plurality. The mere fact that certain features are claimed in different claims does not rule out their combination. Reference numbers in the claims are not intended as a limitation of the scope of protection.

LIST OF REFERENCE NUMBERS

(27) 1 microwave oven

(28) 2, 2′ telescopic slide

(29) 3 side wall

(30) 4 muffle

(31) 5, 5′, 6, 6′, 7, 7′ slide element

(32) 8, 9 ends of the slide elements 5, 6, 7

(33) 10 extension direction

(34) 11, 11′ door

(35) 12, 13 limb

(36) 14, 15 connection portion

(37) 16, 17 bead

(38) 18, 19 protrusion

(39) 20, 21 surface

(40) 22, 23, 24, 25 contact element

(41) 26, 27 ball cage

(42) 28 insulator

(43) 29 ball bearing

(44) 30 shaped silicone part