FR3122458A1 - Reversible fixing device by coaxial interlocking with snapping of two elements - Google Patents

Abstract

The invention relates to a device for fixing by coaxial interlocking snap-fastening of two elements (210, 220), said device comprising several tabs (212) arranged axially on the periphery of the first element (210) and each comprising a snap-fastening tooth ( 213), as well as a corresponding number of recesses (221) formed on the periphery of the second element (220), said recesses being arranged so as to each and simultaneously receive a corresponding tooth during the coaxial snap-fit interlocking of said elements , each said recess being delimited in thickness by a frame having a guide face (227) extending along an inclined plane parallel to the axis of said second element, said guide faces being capable, during the rotational drive of said second element in a direction vis-à-vis said first element while the latter are nested, to cooperate each and simultaneously by sliding with the tooth of a corresponding tab so as to guide said teeth out of said recesses. Figure to be published with abstract: Fig. 6

Description

Reversible fixing device by coaxial interlocking with snapping of two elements

The invention generally relates to devices for fixing by coaxial interlocking with snap-fastening of two elements, such as for example two elements constituting a rotary wheel of a control device for a motor vehicle. It relates in particular to such a fixing device allowing dismantling of these two elements without damaging the snap-fastening means.

It is known from document KR 102101162 B1 to fix two constituent elements of a control panel of the air conditioning system of a motor vehicle by means of a fixing device by coaxial snap-fit interlocking.

Such a device conventionally comprises a plurality of elastically deformable latching tabs formed axially on the periphery of said first element and each comprising a latching tooth, as well as a corresponding number of recesses formed on the periphery of said second element.

These recesses are arranged so as to each and simultaneously receive a said corresponding tooth during the coaxial snap-fit interlocking of said elements, each said recess being delimited in thickness by a frame having a shoulder face capable of axially retaining the tooth of a said corresponding tab when said elements are nested.

Once the two elements are fixed to each other, it is unfortunately almost impossible to dismantle them (for example in the context of an after-sales intervention on the vehicle) without damaging some or all of the tabs. snap-in, so that the corresponding element must be systematically replaced.

The present invention therefore aims to allow these two elements to be disassembled without damaging the snap-in tabs while ensuring effective maintenance of these elements in the mounted configuration.

It proposes for this purpose a device for fixing by coaxial interlocking with snap-fastening of a first element on a second element, said device comprising a plurality of elastically deformable snap-fastening tabs arranged axially on the periphery of said first element and each comprising a tooth of snap-fastening, said device also comprising a corresponding number of recesses made on the periphery of said second element, said recesses being arranged so as to each and simultaneously receive a said corresponding tooth during the coaxial snap-fit interlocking of said first and second elements, each said recess being delimited in thickness by a frame having a shoulder face capable of axially retaining the tooth of a said corresponding tab when said elements are nested; characterized in that said frame of each said recess also has a guide face extending from a leading edge along an inclined plane parallel to the axis of said second element, said guide faces being capable, during training rotation of said second element in a direction vis-à-vis said first element while the latter are nested, to cooperate each and simultaneously by sliding with the tooth of a corresponding tab so as to guide said teeth out of said recesses.

Thanks to the presence of these inclined guide faces, the fixing device according to the invention makes it possible, if necessary, to easily dissociate the first and second elements from each other and without any risk of damage to the snap-fastening tabs, so that it is possible to reattach them to each other without having to replace either of these elements.

The invention also has the advantage of not entailing any particular additional cost of manufacturing said elements.

In order to facilitate their sliding along the lateral guide faces and to avoid any risk of buttressing, each said latching tooth advantageously has a bevelled surface arranged to cooperate by sliding in plane contact with a corresponding guide face during of the rotational drive of said second element in a said direction vis-à-vis said first element.

In order to avoid any risk of unpremeditated rotation of said second element relative to said first element, the fixing device according to the invention preferably comprises unlockable means for securing said second element in rotation relative to said first element.

These unlockable means for fastening in rotation comprise, for example, an elastically deformable finger projecting axially from one of said elements and intended to be housed at least partially, during snap-fit interlocking of said elements, in a corresponding notch formed in the another of said elements, said finger being able to be spaced radially away from said notch to release the rotation of said second element with respect to said first element.

Furthermore, and in order to limit the intensity of the torque to impart to said second element to make it rotate vis-à-vis said first element, the angle of inclination between each guide face and the diametral plane of said second passing element by the leading edge of this guide face is advantageously greater than or equal to 45° and preferably between 50 and 60°.

Advantageously and in order to ensure optimum fixing between these two elements, said tongues and said recesses are angularly distributed in a regular manner respectively on the periphery of said first element and on that of said second element. Their number is for example between three and six.

According to a preferred embodiment of said fastening device according to the invention, said tongues are cut out in an annular peripheral skirt constituting one of the ends of said first element.

Said recesses are for their part advantageously made in corresponding lugs projecting axially in the extension of an annular peripheral strip that comprises said second element.

The outer faces of said lugs are for example inscribed in the same imaginary circle, the diameter of which is slightly smaller than that of the inner faces of portions of lesser thickness that comprises said annular skirt and in which said tabs are arranged at least partially.

The invention also relates, in a second aspect, to a rotary control knob comprising a cylindrical actuating drum constituting a first element, as well as a gripping ring constituting a second element, said first and second elements being fixed to one another. the other by a fixing device according to the invention.

The invention finally relates in a third aspect, to a control device for a motor vehicle comprising a base comprising a hollow cylindrical body, as well as such a control wheel housed at least partially concentrically in said hollow body and rotatably mounted vis- vis-a-vis said base.

Advantageously and for issues of perceived quality and style, only said gripping ring protrudes from said hollow body while said actuating drum is housed entirely in this hollow body.

Finally, and so as to allow the gripping ring of said drum to be removed, said hollow body preferably has a first orifice arranged axially at the same level as a second orifice made in said drum so that these two orifices can occupy a configuration of radial alignment in which the latter can be crossed by the rod of a tool in order to lock said drum in rotation with respect to said base.

The description of the invention will now be continued with the detailed description of an embodiment, given below by way of illustration but not limitation, with reference to the appended drawings, in which:

shows a perspective view of a control device for a motor vehicle comprising a rotary thumbwheel consisting of an actuating drum and a gripping ring mounted one on the other by snap-fit coaxial fitting via the intermediary a fixing device according to the invention;

is a perspective view from another angle of the control apparatus of the on which certain elements are omitted or represented by transparency in order to facilitate reading;

shows a perspective view of the rotary wheel of the control device of the ;

is a perspective view of the rotary wheel operating drum of the ;

shows a perspective view of the grip ring of the rotary wheel of the ;

is a partial perspective sectional view taken along a diametral plane of the rotary wheel after assembly of the gripping ring on the actuating drum;

shows an enlarged sectional view along a transverse plane of a latching zone between the gripping ring and the actuating drum; and

is a partial perspective view of the knob showing the means for securing the gripping ring in rotation with respect to the actuating drum.

The represents a control device 1 for a motor vehicle making it possible to control certain functional systems of the vehicle such as the car radio, the air conditioning system, the telephony or even the autonomous driving system of this vehicle.

The control device 1 comprises a base 100 comprising a hollow cylindrical body 110, a cylindrical control wheel 200 partially housed in said body 11 and rotatably mounted vis-à-vis said base, and a cylindrical control member 300 mounted concentrically in wheel 200.

The control knob 200 is configured to interact with an electronic control circuit, not visible in the figures, housed at the bottom of the hollow body 110 of the base 100 and intended to be electrically connected to a functional unit of the motor vehicle.

As illustrated in Figures 2 and 3, this wheel 200 consists of a cylindrical actuating drum 210 and a gripping ring 220, these two elements each being molded in one piece from a thermoplastic material optionally reinforced with natural and/or synthetic fibres.

The gripping ring 220 is fixed by coaxial snap fitting on the drum 210 and by means of a fixing device according to the invention.

In the rest of this description, the terms "front" and "rear" used to characterize the position of certain elements of the drum 210 and of the gripping ring 220 are to be considered with respect to the direction of snap fitting from front to back of this ring 220 on this drum 210.

The terms "external" and "internal" will be used to define the relative position of an element with reference to the axis of revolution of the drum 210 or of the ring 220. The element closest to this axis will be thus qualified as internal as opposed to the other element further from this same axis which will be qualified as external.

With reference to the , this fastening device comprises four elastically deformable tongues 212 cut out of the drum 210 and more precisely in an annular peripheral skirt 211 forming the front end of this drum 210.

These tabs 212, angularly distributed in a regular manner (i.e. at 90° to each other) on the periphery of the drum 210, extend in axial directions (i.e. parallel to the axis of this drum 210) between a proximal end 212A attached to the skirt 211 and a free distal end 212B opening onto the front peripheral edge 210A of this drum 210.

Each tongue 212 has a ratchet tooth 213 projecting from the inner side of the drum 210 and being formed by an inclined ramp 214 extending rearward from the free distal end 212B of this tongue 212 to a retaining recess 215 (see ).

With reference to the , the fixing device according to the invention also has four through recesses 221 formed in the gripping ring 220 and each intended to cooperate by snapping with a corresponding tongue 212, so as to ensure the fixing of this ring 220 on the drum 210.

Angularly distributed in a regular manner (i.e. at 90° to each other) on the periphery of the ring 220, these four recesses 221 are made in four corresponding tabs 222 projecting axially towards the rear in the extension of an annular peripheral band 223 of this ring 220.

The outer faces of these four tabs 222 are inscribed in the same imaginary circle whose diameter is slightly smaller than that of the inner face of four portions of less thickness 211A of the annular skirt 211 in which the tongues 212 are arranged at least partially ( to see ), so as to be able to cooperate by interlocking with this skirt 211 during the assembly of the ring 220 on the drum 210.

Referring to Figures 5 and 7, each through recess 221 made in a tab 222 is delimited in thickness by a frame having:
- a front face 224 and a rear shoulder face 225 extending along respective planes parallel and perpendicular to the axis of the cob 220,
- a first side face 226 extending substantially along a diametral plane of the ring 220, and
- a second lateral guide face 227 extending along an inclined plane parallel to the axis of the ring 220 between a pointed internal leading edge 227A and an external trailing edge 227B along an inclined plane forming an angle of inclination θ with the diametral plane D of this ring 220 passing through this internal leading edge 227A.

To carry out the assembly of the ring 220 on the drum 210, an operator must first coaxially align these two elements by ensuring that the four tongues 212 of this drum 210 correspond angularly with the four corresponding recesses 221 provided on ring 220.

The operator must then slide the ring 220 back and forth axially in the direction of the drum 210 until the ramps 214 of the teeth 213 come to bear against the free rear edge of the lugs 222.

The continuation of this sliding movement of the ring 220 causes the stress on these ramps 214 and causes the separation of the tabs 212.

When the teeth 213 are found opposite the recesses 222, these tabs 212 immediately return to their initial position (these teeth 213 then penetrating into these recesses 222) so as to secure the ring 220 to the drum 210 (the recesses 215 of the teeth 213 now opposite the rear faces of the shoulder 225 of the recesses 222 then opposing the axial withdrawal of the ring 220 away from the drum 210).

To separate the ring 220 from the drum 210, the operator must rotate this ring 220 counterclockwise relative to the drum 210 so that one of the internal corners of each tooth 213 comes to bear against the lateral guide face. 227 of the corresponding recess 222 (see Figures 6 and 7).

The continuation of this rotational movement of the ring 220 causes the sliding of the teeth 213 along the lateral guide faces 227 of the recesses 222 and the progressive separation of the tabs 212 on the external side until the teeth 213 come out of these recesses 222 so as to allow the separation of this ring 220 and the drum 210 via an axial withdrawal movement from back to front.

As illustrated in particular in Figures 6 and 7 and in order to facilitate their sliding along the lateral guide faces 227 and to avoid any risk of buttressing, the internal corners of the teeth 213 advantageously each have a beveled surface 217 arranged to cooperate in plane contact with the lateral guide face 227 of a corresponding recess 222.

Furthermore, and in order to limit the intensity of the torque to be imparted to the ring 220 to make it rotate vis-à-vis the drum 210, the angle of inclination θ between each lateral guide face 227 and the diametral plane D of the ring 220 passing through the leading edge 227A of this guide face is advantageously greater than or equal to 45° and preferably between 50 and 60°.

It will be noted in support of Figures 1 and 2 that in the mounted configuration of the control device 1, only the gripping ring protrudes from the hollow body 110 while the drum 210 is entirely housed inside the hollow body 110 so that it is not possible to retain it manually so that the ring 220 can rotate relative to it.

In order to prevent this rotation of the drum 210 inside this hollow body 110, the control device 1 is thus provided with rotation locking means.

These locking means comprise a first circular orifice 111 provided in the hollow body 110 as well as a second circular orifice 218 provided in the drum 210 and arranged axially at the same level as the first orifice 111 so that these two orifices 111, 218 can occupy a radial alignment configuration shown in the and in which the latter can be crossed by the rod of a tool (for example a screwdriver) in order to lock the drum 210 in rotation with respect to the base 100.

Visual indexing marks, not shown, can advantageously be arranged on the outer faces of the ring 220 and of the hollow body 110 of the base 100 in order to facilitate the positioning of these orifices 111, 218 in the alignment configuration.

Referring to Figures 5 and 8, the fastening device according to the invention also advantageously comprises unlockable means for securing in rotation the gripping ring 220 relative to the drum 210.

These means comprise in this case an elastically deformable finger 228 projecting axially from the rear peripheral edge 220A of the annular ring 220 between two tabs 222 and intended to be housed at least partially, during assembly by snap fitting of this ring 220 on the drum 210, in a corresponding notch 219 formed in the annular portion 211 of the drum 210 and opening onto the front peripheral edge 210A of the latter.

This finger 228 and this notch 219 make it possible to avoid any risk of unpremeditated rotation of the ring 220 with respect to the drum 210 which could cause accidental separation of the latter. They also make it possible to ensure, during the assembly of the ring 220 on the drum 210, the correct angular indexing of these two elements with respect to each other.

It will be noted on this occasion that the front end of insertion of the notch 219 is advantageously chamfered in order to serve as a guide for the free end of the finger 228 so as to facilitate its insertion therein.

To release the rotation of the ring 220 with a view to disassembling it from the drum 210, the operator must thus first insert the end of the rod of a tool through the notch 219 to radially move the finger 228 away from the internal side of this ring 220 away from this notch.

The drum 210 being entirely housed inside the hollow body 110 in the mounted configuration of the control device 1, access to this notch 219 is not directly possible.

In order to allow the stem of a tool to access this notch 219 from outside the control device 1, the hollow body 110 of the base 100 has a circular hole 112 made axially at the level of the notch 219 and arranged so as to be radially aligned with the latter when the orifices 111, 218 are also radially aligned (see ).

In order to simplify the dismantling operations, the orifice 111 and the hole 112 are aligned axially on the hollow body 110 of the base, while the orifice 218 and the notch 219 are aligned axially on the drum 210.

According to variant embodiments of the fixing device according to the invention, the number of tabs and recess may be different, for example equal to three or six while remaining at least equal to two so as to ensure suitable fixing.

According to other variant embodiments, the recesses are shaped differently. The latter can for example be blind and/or be delimited in thickness by a frame having two lateral guide faces inclined such as 227 so as to allow the ring to be dismantled by rotating it in one direction or the other relative to the drum.

According to yet other variants not shown, the fixing device according to the invention can be used to fix two elements other than a drum and a ring of a control wheel to each other.

Finally, it is recalled that the present invention is not limited to the embodiments described and represented, but that it encompasses any variant of execution within the reach of those skilled in the art.

Claims (15)

Device for fixing by snap-fastening coaxial interlocking of a first element (210) on a second element (220), said device comprising a plurality of elastically deformable snap-in tabs (212) provided axially on the periphery of said first element (210) and each comprising a latching tooth (213), said device also comprising a corresponding number of recesses (221) provided on the periphery of said second element (220), said recesses (221) being arranged so as to each and simultaneously receive said corresponding tooth (213) during the coaxial snap-fit fitting of said first and second elements (210, 220), each said recess (221) being delimited in thickness by a frame having a shoulder face (225) able to axially retaining the tooth (213) of said corresponding tongue (212) when said elements (210, 220) are nested; characterized in that said frame of each said recess (221) also has a guide face (227) extending from a leading edge (227A) along an inclined plane parallel to the axis of said second element (220), said guide faces (227) being suitable, during the rotational drive of said second element (220) in a direction vis-à-vis said first element (210) while the latter are nested, to cooperate each and simultaneously by sliding with the tooth (213) of a corresponding tab (212) so as to guide said teeth (213) out of said recesses (221). Fixing device according to Claim 1, characterized in that each said ratcheting tooth (213) has a bevelled surface (217) arranged to cooperate by sliding in plane contact with a corresponding guide face (227) during driving. rotating said second member (220) in a said direction relative to said first member (210). Fixing device according to one of Claims 1 or 2, characterized in that it comprises unlockable means for securing in rotation (219, 228) said second element (220) with respect to said first element (210). Fastening device according to Claim 3, characterized in that the said unlockable means for fastening in rotation comprise an elastically deformable finger (228) projecting axially from one (220) of the said elements (210, 220) and provided to be housed in the less partially, when said elements (210, 220) snap-fit into a corresponding notch (219) made in the other (210) of said elements (210, 220), said finger (228) being able to be spaced radially away from said notch (219) to release rotation of said second member (220) relative to said first member (210). Fixing device according to one of Claims 1 to 4, characterized in that the angle of inclination (θ) between each guide face (227) and the diametral plane (D) of the said second element (220) passing through the leading edge (227A) of this guide face (227) is greater than or equal to 45°. Fastening device according to Claim 5, characterized in that the said angle of inclination (θ) is between 50 and 60° Fixing device according to one of Claims 1 to 6, characterized in that the said tongues (212) and the said recesses (221) are distributed angularly in a regular manner respectively on the periphery of the said first element (210) and on that of the said second element. (220). Fixing device according to Claim 7, characterized in that the number of said tabs (212) and of said recesses (221) is between three and six. Fastening device according to one of Claims 1 to 8, characterized in that the said tabs (212) are cut out from an annular peripheral skirt (211) constituting one of the ends of the said first element (210). Fastening device according to one of Claims 1 to 9, characterized in that the said recesses (221) are made in corresponding lugs (222) projecting axially in the extension of an annular peripheral strip (223) which the said second element comprises. (220), Fixing device according to Claims 9 and 10, characterized in that the external faces of the said lugs (222) are inscribed in the same imaginary circle, the diameter of which is slightly smaller than that of the internal faces of portions of lesser thickness (211A) which said annular skirt (211) and in which said tabs (212) are arranged at least partially. Rotary control wheel (200) comprising a cylindrical actuating drum (210) constituting a first element, as well as a gripping ring (220) constituting a second element, characterized in that the said first and second elements (210, 220 ) are fixed to each other by a fixing device according to one of claims 1 to 11. Control device (1) for a motor vehicle comprising a base (100) comprising a hollow cylindrical body (110), as well as a control knob (200) according to claim 12 housed at least partially concentrically in said hollow body ( 110) and rotatably mounted vis-à-vis said base (100). Control device according to Claim 13, characterized in that only the said gripping ring (220) protrudes from the said hollow body (110) while the said actuating drum (210) is housed entirely in this hollow body (110). Control device according to Claim 14, characterized in that the said hollow body (110) has a first orifice (111) arranged axially at the same level as a second orifice (218) provided in the said drum (210) so that these two orifices (110, 218) can occupy a configuration of radial alignment in which the latter can be crossed by the rod of a tool in order to lock said drum (210) in rotation with respect to said base (100).