WO2019137744A1

WO2019137744A1 - Clamping sleeve for connecting a domestic appliance rotary knob to a shaft

Info

Publication number: WO2019137744A1
Application number: PCT/EP2018/085236
Authority: WO
Inventors: Franz Grätz; Engelbert Ober; Roman Schemmerer; Konrad Weinbrenner
Original assignee: BSH Hausgeräte GmbH
Priority date: 2018-01-15
Filing date: 2018-12-17
Publication date: 2019-07-18
Also published as: DE102018200531A1; EP3740838A1

Abstract

The invention relates to a clamping sleeve (2) for connecting a domestic appliance rotary knob (1) to a shaft (3) of a domestic appliance (H), having a longitudinally slotted sleeve-shaped main part (7) which has at least one claw (8, 9) that is machined from the main part (7) and curves inwards, wherein a free edge (10) of the at least one claw has a first section (11) and a second section (12) which are angled towards each other and transition into one another at a tip (13) of the claw. The first section is designed to be recessed deeper in the rotary knob than the second section, and the first section and the second section are angled towards a main part cross-sectional plane (Q) running through the tip such that the first section has a flatter angle relative to the cross-sectional plane than the second section. A domestic appliance rotary knob has a sleeve receiving area (4) for the clamping sleeve, said sleeve receiving area being open on the cooking appliance-side and receiving the clamping sleeve according to one of the aforementioned claims at least in a force-fitting manner.

Description

Clamping sleeve for connecting a household appliance rotary knob with a shaft

The invention relates to a clamping sleeve for connecting a household appliance rotary knob with a shaft of a household appliance, the invention also relates to a household appliance rotary knob, comprising a gargeräteesig open sleeve receptacle for the clamping sleeve, in which the clamping sleeve is at least positively received. The invention further relates to a household appliance, comprising at least one protruding - in particular rotatable - shaft, wherein the shaft is inserted into a shaft receiving the clamping sleeve. The invention is particularly advantageously applicable to cooking appliances, especially ovens and / or hobs.

US 3,730,571 discloses a fastener for releasably connecting a shaft end to a knob, handle or similar cooperating member, the fastener having a hollow housing portion for receiving the shaft and a pair of band-like means thereon secured by a recessed elastic member. connected bridge which provides a leaf spring-like connection with the shaft.

DE 76 12 978 U discloses a clamp for frictional connection of a Drehknop- fes with a flattened end of a round bar body, consisting of a substantially cylindrical, longitudinally slotted, sleeve-shaped part, the holding parts resiliently against the wall of the recess in the knob put when this part on the wall circumference has a portion which hangs clamped on the flattened end of a rod body.

It is the object of the present invention to overcome the disadvantages of the prior art, at least in part, and in particular to provide a structurally simple way to keep a Aufsteckkraft a rotary knob on a shaft noticeably smaller than a withdrawal force of the rotary knob of this shaft ,

This object is achieved according to the features of the independent claims. Advantageous embodiments are the subject of the dependent claims, the description and the drawings. The object is achieved by a clamping sleeve for connecting a household appliance rotary knob to a shaft of a domestic appliance, comprising a longitudinally slotted, sleeve-shaped basic body which has at least one inwardly bent partial area (hereinafter referred to as "universal") which is machined out of the basic body. Claw "), wherein a free edge of the at least one claw has a first portion and a second portion which are angled towards each other and merge at a tip of the claw, the first portion is intended to be sunk deeper in the rotary knob as the second portion, the first portion and the second portion are angled against a cross-sectional plane of the base body extending through the tip, such that the first portion has a shallower angle with respect to the cross-sectional plane than the second portion.

This clamping sleeve has the advantage that due to these different angles a Aufsteckkraft of the household appliance rotary knob on the shaft is significantly lower than a withdrawal force required to pull off the rotary knob of the shaft. It is exploited that during a movement of the (in particular inserted in the rotary knob) clamping sleeve against the shaft of the front in the direction of travel, pressed onto the shaft portion of the free edge a significantly greater mechanical resistance (in particular frictional resistance) than the back, section pulled over the shaft. The flatter the angle of the front portion in the direction of movement, the greater the mechanical resistance. In a Aufsteckbewegung the second section is the front section, in a withdrawal movement, however, the first section is the front section. Since the angle of the first section is noticeably flatter than the angle of the second section, a force ("pull-off force") must be used to pull off the clamping sleeve, which force is considerably higher than a force required for attachment ("pull-off force").

This clamping sleeve has the further advantage that it is robust and easy to manufacture.

The household appliance may be an electrically operated household appliance. The household appliance can be a large household appliance or a small household appliance. A household appliance can eg a cooking appliance such as a hob, an oven, a microwave oven, a Steam treatment device or any combination thereof (eg a stove). But it may also be a laundry care device such as a washing machine, a tumble dryer or a combination thereof, a dishwasher, a refrigerator, etc. The household small appliance can be eg a coffee machine, a toaster etc. The household appliance is in particular a kitchen appliance.

The sleeve-shaped main body has in particular a cylindrical, open-sided basic shape. Its inner side is provided for contacting the shaft (in particular for inserting the shaft), while an outer side for contacting the rotary knob is provided, in which the clamping sleeve is provided for insertion. The interior of the clamping sleeve is intended to receive the shaft, thus serving as a "shaft receiver". The claws thus protrude into the shaft receptacle and are displaced when the shaft is inserted and elastically bent outward. When the shaft is inserted, the claws then press on the side of the shaft due to the elastic restoring force.

The main body is associated in particular with a longitudinal extent. The longitudinal extension extends in particular parallel to or on a longitudinal axis of the main body and / or the shaft.

The fact that the claw is carved out of the base body means, in particular, that it has been produced in one piece with the base body and has not been subsequently attached to the base body. It still remains connected to the main body or represents a partial area of the main body. The working out can be implemented, for example, by machining the basic body. It is a development that the clamping sleeve is made in one piece from a semifinished product, e.g. by singulation such as punching, cutting, etc. and subsequent forming, e.g. To bend. For example, the clamping sleeve may have been produced from a semifinished product in the form of a sheet metal.

The claw has a free or exposed edge which has a first portion and a second portion, and especially only these two portions.

It is a development that the apex of the edge is angular, but it can also be rounded. That the first portion is intended to be sunk deeper in the rotary knob than the second portion, comprising that the clamping sleeve is intended to be inserted with the first portion in advance in the rotary knob. This may include, in particular, that the first section and the second section are arranged on opposite sides of a cross-sectional plane of the main body extending through the tip.

It is a further development that the clamping sleeve consists of a material which is elastic under typical stresses, e.g. Metal or plastic. In this case, metal may be preferred, since it can provide particularly high elastic restoring forces. For example, the clamping sleeve may be made of spring steel.

It is an embodiment that the first portion and the second portion are formed as rectilinear portions with respect to a plane shape. This allows a particularly simple production and also a particularly simple adjustment of Aufsteckkraft and withdrawal force. In particular, "straight-line with respect to a planar shape" can be understood to mean that the sections are rectilinear if the claw were to lie in a plane or be rolled up into a plane. This can e.g. be the case when the clamping sleeve is made of a flat sheet metal. The edge is then exposed as a straight line from the sheet. This embodiment can also be described so that the sections each follow (in the finished, curved state of the clamping sleeve) a helical line with a constant pitch. Their radius with respect to a longitudinal axis of the main body or of the shaft is then in particular smaller than a radius of the curved wall region of the main body. The slopes of the first section and the second section have different signs (ascending or descending with the same direction of rotation, or vice versa). However, in principle, the first portion and the second portion may also be at least partially curved with respect to the plane shape, e.g. do not have a constant incline.

It is an embodiment that the base body has a plurality of claws distributed in the circumferential direction, in particular exactly two claws arranged mirror-symmetrically with respect to one another. Thus, the advantage is achieved that when plugging in and disconnecting pulling the rotary knob on the clamping sleeve acting forces are evenly distributed and act.

It is an embodiment that the at least one claw is arranged on a device-side lower edge of the base body. As a result of this embodiment, the clamping sleeve can be produced in a particularly simple manner and, in addition, the attachment force and the withdrawal force act on the shaft for a particularly long distance.

It is an embodiment that free ends of the main body formed by a continuous longitudinal slot of the main body are formed to outwardly extending, opposite ("tab-like") portions. This provides the advantage that an increase in the transmittable torque between the shaft and rotary knob can be achieved, for example, by the fact that the two tab-like portions (also referred to simply as "tabs") can be guided in a groove of the rotary knob.

It is an embodiment that the basic body has a basic shape that is D-shaped in cross-section and that the tab-like partial areas protrude substantially perpendicularly from a flat side of the basic body. The D-shaped basic shape has the advantage that the clamping sleeve can be inserted into the rotary knob at a precisely defined angle, and even particularly high torques can be reliably transmitted. A D-shaped cross section may in particular be understood to mean a circular or oval shape or contour which has a straight section. On the straight section, the clamping sleeve forms the flat side over its longitudinal extent. The claws are then advantageously provided in the curved wall region of the clamping sleeve, in particular mirror-symmetrical one of the continuous longitudinal slot having mirror plane.

It is an embodiment that the base body has at least one inwardly curved (ie, in which provided for receiving the shaft shaft receiving) web. This can also be expressed so that the webs protrude into the space provided for receiving the shaft interior. As a result, the advantage is achieved that the clamping sleeve can be fastened particularly reliable over its length on the shaft. It is one Further, that the at least one web is aligned in the longitudinal extent of the base body.

The object is also achieved by a household appliance rotary knob, comprising a device-side open receptacle for the clamping sleeve (hereinafter referred to as "sleeve receptacle" without limiting the generality), in which the clamping sleeve is received at least non-positively. In other words, the inner cavity of the body serves as the sleeve receptacle.

The household appliance rotary knob can be designed analogously to the clamping sleeve and has the same advantages. A longitudinal axis of the shaft receptacle may in particular correspond to a designated axis of rotation of the rotary knob. The rotary knob can be provided for rotating the rotatable shaft and optionally also for their impressions. An "at least frictional" Aufnehmung can be understood as a frictional Aufnehmung only, a frictional and positive (for example, releasable or non-releasable latched) Aufnehmung, a frictional and cohesive (for example, by gluing) Aufnehmung or a frictional, positive and cohesive Aufnehmung. An interlocking connection exists when at least two connection partners intervene, with the connection partners not loosening even without or with an interrupted power transmission. In the case of a non-positive connection of two connection partners, a mutual displacement is prevented when a corresponding force is applied, as long as the counterforce caused by the static friction is not exceeded. The force or frictional connection is lost and the surfaces slip on each other when a tangentially acting load force is greater than the static friction force. Cohesive compounds are compounds in which the connection partners are held together by atomic or molecular forces. They are at the same time non-detachable connections, which can only be separated by destruction of the connecting means.

It is an embodiment that the sleeve receptacle is a senaufnahme in cross-section D-shaped Hül. Thus, the advantage is achieved that, together with a clamping sleeve which has a base body with a D-shaped basic shape, a particularly reliable torque transmission is achieved and also the clamping sleeve with a precisely predetermined rotational position can be used to the rotary knob in this. It is an embodiment that the sleeve receptacle has a laterally arranged longitudinal groove, in which the tab-like portions of the clamping sleeve are introduced. This enables an improved better torque transmission, in particular even at very high torques.

It is a development that the tab-like portions are introduced by clamping in the longitudinal groove. As a result, the advantage is achieved that a rotational play of the rotary knob against the clamping sleeve can be reduced even more reliably. Also, such an unwanted slipping out of the clamping sleeve from the sleeve receptacle is particularly reliably avoided, which is e.g. simplified installation of the rotary knob on the appliance.

The object is also achieved by a household appliance, comprising at least one above - in particular rotatable - shaft, wherein the shaft is inserted into the shaft receiving the clamping sleeve. The household appliance can be designed analogous to the rotary knob and the clamping sleeve and gives the same advantages.

The at least one protruding shaft can be arranged on an upper-side or front-side operating region of the household appliance.

The domestic appliance may have one or more such shafts with rotary gags attached thereto. The shaft can serve as a torque transformer to a Drehwinkelsen- sensor and / or to a rotary knob. The household appliance may be designed to control an operation of the household appliance on the basis of an angular position of the shaft detected by means of a rotation angle sensor and / or on the basis of a rotational position of the rotary controller. The knob can be an energy regulator. The rotary control can be designed as a potentiometer.

It is a further development that the shaft has a D-shaped cross-sectional shape at least in its longitudinal section inserted into the clamping sleeve. Thus, the advantage is achieved that a high torque transmission between rotary knob and shaft is achieved and also the shaft can be used with a precisely predetermined rotational position to the rotary knob in this. It is an embodiment that the shaft has at least one recess, in particular annular groove, and the at least one claw engages in the at least one recess when the shaft is fully inserted. As a result, the advantage is achieved that the clamping sleeve with the shaft - in particular releasably - can be locked. The latching provides additional resistance to initial withdrawal of the rotary knob or collet from the shaft and also creates an audible and / or tactile action to ensure a correct attachment of the rotary knob to the shaft.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following schematic description of an embodiment which will be described in more detail in conjunction with the drawings.

1 shows an oblique view of a rotary knob with inserted clamping sleeve in front of an attachment to a shaft;

2 shows the rotary knob with the inserted clamping sleeve as a sectional view in plan view;

3 shows an oblique view of a section of the clamping sleeve;

4 shows an oblique view of the clamping sleeve at a first contact with the

Wave; and

5 shows an oblique view of the rotary knob with inserted clamping sleeve with complete attachment to the shaft.

1 shows an oblique view of a rotary knob 1 with clamping sleeve 2 inserted therein in front of an attachment to a shaft 3 of a domestic appliance H, e.g. an oven or a stove. The wave 3 is only partially shown with her chamfered tip. The household appliance H can have one or more such shafts 3 with rotary lugs 1 attached or to be fastened thereto. The shaft 3 can serve as a torque transmitter to a rotation angle sensor and / or to a rotary knob (o. Fig.). 2 shows the rotary knob 1 with the inserted clamping sleeve 2 as a sectional view in plan view.

The rotary knob 1 has a recess ("sleeve receptacle 4") which is open on the appliance side and is closed away from the appliance, in which the clamping sleeve 2 is inserted. The clamping sleeve 2 is provided for connecting the rotary knob 1 with a shaft 3 and has a longitudinal slot slotted on a continuous longitudinal slot 6, frontally open sleeve-shaped base body 7.

The shaft 3, the sleeve receptacle 4 and the base body 7 are formed in cross-section D-shaped and fit so against rotation into each other. The sleeve receptacle 4 has on its flat side a longitudinal extension of the sleeve receptacle 4 aligned longitudinal groove 5.

Starting from a device-side edge of the clamping sleeve 2, two curved claws 8, 9 worked out from the base body 7 and projecting inwards (i.e. protruding into an internal cavity 14 of the main body 4 serving as a shaft receiver) are present. The claws 8, 9 are mirror-symmetrical to one another, in particular mirror-symmetrically with respect to a mirror plane extending along the sleeve receptacle 4 through the longitudinal slot 6 (not shown).

The clamping sleeve 2 also has two out of the base body 7 worked out, bent outward portions (hereinafter referred to as "retaining tabs" 18 without limitation of the generality) on. The retaining tabs 18 serve the clamping sleeve 2 similar to barbs or the like. to keep in the rotary knob 1. This is achieved in that the retaining tabs 18 are bent in the direction of the sleeve receptacle 4 when inserting the clamping sleeve 2 and then press against the wall of the sleeve receptacle 4 due to their elastic springback with a free edge.

As shown by an enlarged section in Figure 3 for the claw 8, a free edge 10 of the respective claws 8, 9, a first portion 11 and a second portion 12 which are angled against each other and at a tip 13 of the claw 8 into each other pass. The first section 11 is farther away from the household appliance H in comparison with the second section 12 and is arranged lower in the sleeve receptacle 4 than the second section 12.

The first section 1 1 and the second section 12 are angled so against a running through the top 13 cross-sectional plane Q of the base body 7, that the first section 1 1 has a shallower angle a with respect to the cross-sectional plane Q than the second section 12. The second Section 12 thus has one with the io

Cross-sectional plane Q enclosing angle ß, where a <ß applies. The two sections are inclined with respect to the cross-sectional plane Q in different directions. The two sections 11 and 12 are each formed as rectilinear sections with respect to a plane shape.

By the continuous longitudinal slot 6 formed free ends of the main body 7 are formed to outwardly extending, opposing tabs 15. The tabs 15 are perpendicular from a flat side 16 of the base body 7 and are non-positively accommodated in the longitudinal groove 5. The tabs 15 are here band-shaped, in particular band-shaped, shaped.

Furthermore, the main body 7 has two webs 17, which are bent slightly in the inner cavity 14 and are aligned in the longitudinal extension of the main body 7.

4 shows an oblique view of the clamping sleeve 2 at a first contact with the shaft 3. The rotary knob 1 is not shown, but may be present. The free, chamfered end of the shaft 3 is already inserted into the device-side end of the clamping sleeve 2, so that the device-side edge of the clamping sleeve 2 rests on the shaft 3.

Now, if the clamping sleeve 2 is pressed with a Aufsteckkraft Fa on the shaft, the claws bend 8 and 9 to the outside, as indicated by the arrow. The second section 12 is pressed due to its elastic restoring force on the shaft 3 and acts as a determining mechanical resistance to the Aufsteckbewegung. The strength of the mechanical resistance of the claws 8 and 9 is significantly determined by the angle ß of the second portion 12: the larger the angle ß, the lower the resistance. Subsequently, the webs 17 press the clamping sleeve 2 on the shaft 3, wherein the clamping force for the height of the required Aufsteckkraft Fa compared to the effect of the second portion 12 is typically rather low.

FIG. 5 shows, in an oblique view, the rotary toggle 1 with inserted clamping sleeve 2 with a complete attachment to the shaft 3. The shaft 3 is therefore inserted into the inner cavity 14 of the clamping sleeve 2. The claws 8 and 9 engage with their tip 13 in a recess, in particular annular groove, (o. Fig.) Of the shaft 3, whereby the clamping sleeve 2 is releasably locked to the shaft 3. If a withdrawal force Fb, which is opposite to the attachment force Fa, is applied to the rotary toggle 1, the withdrawal movement of the first section 11 acts as a determining mechanical resistance. Since the angle a is smaller than the angle β, the size of the resistance when peeling is greater than when plugging. It is true that the withdrawal force Fb required for removal is appreciably greater than the attachment force required for removal, ie Fb> Fa.

If the pull-off force Fb is exerted on the rotary knob 1, the retaining tabs 18 dig into the softer material of the wall of the sleeve receptacle 4 and are also slightly spread apart. The retaining tabs 18 thereby cause clamping sleeve 2 remains in the rotary knob 1.

Of course, the present invention is not limited to the illustrated embodiment.

In general, "on", "an", etc. can be understood to mean a singular or a plurality, in particular in the sense of "at least one" or "one or more", etc., unless this is explicitly excluded, e.g. by the expression "exactly one", etc.

Also, a numerical value may include exactly the specified number as well as a customary tolerance range, unless this is explicitly excluded.

LIST OF REFERENCE NUMBERS

1 rotary knob

2 clamping sleeve

3 wave

4 sleeve holder

5 longitudinal groove

6 longitudinal slot

7 basic body

8 claw

9 claw

10 free edge

1 1 First section of the free edge

12 Second section of the free edge

13 tip

14 cavity

15 tab

16 Flat side of the main body

17 footbridge

18 holding tab

Fa attachment force

Fb deductibility

H home appliance

Q cross-sectional plane

a angle

ß angle

Claims

claims

1. clamping sleeve (2) for connecting a household appliance rotary knob (1) with a shaft (3) of a household appliance (H), comprising

a longitudinally slotted sleeve-shaped base body (7), the at least one of the base body (7) worked out, inwardly curved claw (8, 9) up, wherein

a free edge (10) of the at least one claw (8, 9) has a first section (1 1) and a second section (12), which are angled towards one another and attached to a tip (13) of the claw (8, 9 ), the first section (11) is intended to be lowered lower in the rotary knob (1) than the second section (12), and

the first section (11) and the second section (12) are angled against a cross-sectional plane (Q) of the main body (7) extending through the tip (13) in such a way that the first section (11) is at a shallower angle the cross-sectional plane than the second section (12).

2. clamping sleeve (2) according to claim 1, wherein the first portion (11) and the second portion (12) are formed as rectilinear with respect to a planar shape sections.

3. clamping sleeve (2) according to any one of the preceding claims, wherein the Grundkör- per (7) distributed in the circumferential direction arranged claws (8, 9), in particular exactly two mirror-symmetrically arranged claws (8, 9).

4. clamping sleeve (2) according to any one of the preceding claims, wherein the at least one claw (8, 9) on a device-side lower edge of the base body (7) is arranged.

5. Clamping sleeve (2) according to one of the preceding claims, wherein by a continuous longitudinal slot (6) of the base body (7) formed free ends of Base body (7) are formed to outwardly extending, opposite tab-like portions (15).

6. clamping sleeve (2) according to claim 5, wherein the base body (7) has a cross-sectionally D-shaped basic shape and the tab-like portions (15) substantially perpendicularly projecting from a flat side (16) of the base body (7).

7. Clamping sleeve (2) according to one of the preceding claims, wherein the base body (7) has at least one inwardly bent web (17).

8. Domestic appliance rotary knob (1), comprising a Gargeräteesig open sleeve receptacle (4) for the clamping sleeve (2), in which the clamping sleeve (2) is taken according to one of the preceding claims at least non-positively.

9. Appliance rotary knob (1) according to claim 8, wherein the sleeve receptacle (4) is a cross-sectionally D-shaped receptacle.

10. Domestic appliance rotary knob (1) according to claim 9, wherein the sleeve receptacle (4) has a laterally arranged longitudinal groove (5) into which the tab-like partial areas (15) of the clamping sleeve (2) are introduced according to claim 5.

1 1. Household appliance (H), comprising at least one protruding shaft (3), which is inserted into a through the interior of the clamping sleeve (2) according to one of claims 1 to 7 formed wave receptacle (14).

12. Household appliance (H) according to claim 11, wherein the shaft (3) at least in its in the clamping sleeve (2) according to claim 6 inserted longitudinal portion has a D-shaped cross-sectional shape.

13. Household appliance (H) according to any one of claims 11 or 12, wherein the shaft (3) has at least one recess, in particular annular groove, and the at least one claw (8, 9) (8, 9) with fully inserted shaft (3) engages in the at least one depression.