Abstract:
The invention concerns a remote control device for a motor vehicle comprising a cable ( 22 ) whereof the ends ( 26, 28 ) are each provided with a connecting piece ( 34, 36 ), a sleeve ( 24 ) wherein the cable can slide such that the cable ends ( 26, 28 ) exceed the sleeve ends ( 30, 32 ), and clips ( 42, 44 ) for interlocking the sleeve ends on parts of the vehicle. The connecting pieces ( 34, 36 ) and the clips ( 42, 44 ) are overmoulded on the cable and on the sleeve respectively from a common plastic material, thereby enabling to control accurately the distance (A or B) between the connecting piece and the clip.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a remote control device by cable for motor vehicle equipment such as, for example, a heating and/or air conditioning unit of the passenger compartment of such a vehicle. 
     BRIEF SUMMARY OF THE INVENTION 
     The device of the invention is of the type comprising a cable, the ends of which are each provided with a connecting piece, a sleeve in which the cable can slide so that the ends of the cable project from the ends of the sleeve, as well as clips that are capable of attaching the ends of the sleeve onto parts of the vehicle. 
     In known devices of this type, one of the clips is generally fixed to a control panel provided on the dashboard of the vehicle, whereas the other clip is fixed to the actual equipment. 
     Normally, one of the ends of the cable is provided to be connected to the end of a pivoting lever that is operated by a control knob, whereas the other end of the cable is provided to be connected to the end of another lever which operates a mobile element of the equipment. 
     In the case of a heating and/or air conditioning unit of a motor vehicle, this latter lever most frequently serves to activate the rotational displacement of a pivoting flap which controls a flow of air. 
     Such control devices by cable raise in particular questions of control, given that it is necessary to be able to bring two limit of travel positions of the control device (generally a rotary knob) to correspond with two respective limit of travel positions of a movable element of the equipment of the vehicle. 
     In other words, it is necessary to adjust accurately the difference between the length of the cable (defined between its two ends), and the length of the sleeve (defined between its two ends or between its two clips). This difference in length is also called “functional projection”. 
     The regulation of this difference in length is difficult to control given that the sleeve and the cable both have a dimensional tolerance. In fact, the tolerance of the sleeve may reach values of more or less 1 mm, even more or less 2 mm, whereas the cable itself has a dimension tolerance of more or less 1 mm. As a result the abovementioned difference, corresponding to the value of the functional projection, may have a tolerance of more or less 3 mm in relation to its nominal value. 
     Different solutions have already been proposed to try to resolve this problem. 
     One solution consists of regulating the “functional projection” directly on the-assembly line of the vehicle by placing a fastening clamp of the sleeve at one of the ends of said sleeve, generally on the side of the housing of the equipment. This solution requires access to an experienced operator, which complicates the mounting operations and also increases their cost. 
     The regulation of the dimension of the “functional projection” before assembly on the assembly line is also known. This regulation may be achieved, for example, by a screw regulating device situated in the middle of the remote control device, or by a device with a clamp fitting, as disclosed by document EP 0 492 289. There too, these solutions are long and expensive to implement. 
     Other solutions consist in using self-adjusting spring devices between the cables and the sleeve. These devices are expensive and do not ensure great reliability. 
     The object of the invention is in particular to overcome the above-mentioned drawbacks. 
     In particular, it aims to obtain a remote control device of the type defined above, which allows a precise regulation of the functional projection to be ensured before mounting on the vehicle. 
     For this purpose the invention proposes a remote control device of the type defined in the introduction, in which the connecting pieces and the clips are overmoulded respectively onto the cable and the sleeve from the same plastic material. 
     Thus, the two connecting pieces and the clips may be overmoulded in well-defined respective positions, which allows the “functional projection” to be adjusted each time with a slight tolerance. 
     The invention advantageously specifies that a connecting piece and an associated clip are overmoulded simultaneously with a precise control of the distance between the connecting piece and the clip. 
     In a preferred embodiment of the invention, the two connecting pieces are identical. The latter preferably each have a shape generated by revolution, in particular a substantially spherical shape, preferably in relation to the axis of the cable. 
     In this preferred embodiment of the invention, the two clips are identical. 
     Thus, when the two connecting pieces are identical and the two clips are also identical, the remote control offers a symmetry and it may therefore be installed in any manner, without it being advisable to choose a particular mounting direction. 
     In the case in which the two clips are identical, they may have a shape generated by revolution, in particular a substantially cylindrical shape, preferably in relation to the axis of the sleeve. Such a shape is essentially suitable for a radial connection of the clip onto a support forming part of the vehicle. 
     In another refinement, each clip comprises axial snapping means and radial snapping means for the connection of the clip at will, either onto a support with axial attachment, or onto a support with radial attachment. 
     In this particular case, it is advantageously specified that each clip comprises a split muff for the axial snapping, which depends on a ring for the radial snapping, the muff being situated on the side the end of the sleeve. 
     This split muff advantageously comprises axial slots which between them delimit axial lugs equipped with respective hooks capable of bending radially. 
     In another embodiment of the invention, the two clips are different. 
     Thus, one of the clips may comprise a ring capable of being snapped radially into a receiver block of the vehicle, whereas the other clip may comprise a ring equipped with a snapping member capable of being received in another receiver block of the vehicle. 
     In the different embodiments of the invention, the connecting pieces and the clips are preferably made of a thermoplastic material, which is advantageously filled. 
     It may involve, for example, a material of the polyoxymethylene (POM) type, or of the polypropylene type, filled with talc. 
     From another angle, the invention relates to a process for manufacturing a remote control device such as that previously defined, which comprises the following operations: 
     a) providing for a sleeve in which a cable is threaded in such a manner that the ends of the cable project beyond the ends of the sleeve; and 
     b) overmoulding, from the same plastic material, two connecting pieces respectively onto the two ends of the cable and two clips respectively onto the two ends of the sleeve. 
     In operation b), it is advantageously specified that a connecting piece and an associated clip are simultaneously overmoulded with a precise control of the distance between the connecting piece and the clip. 
     Thus, it may be specified that operation b) firstly comprises the simultaneous overmoulding of a connecting piece and of an associated clip, then the simultaneous overmoulding of another connecting piece and an associated clip. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following description, given only by way of example, reference is made to the attached drawings, on which: 
     FIG. 1 is a diagrammatical representation of a device according to the invention applied to the control of a rotary flap that forms part of a heating and/or air conditioning unit for a motor vehicle, from a rotary knob; 
     FIG. 2 diagrammatically represents the control device itself (cable and sleeve) with overmoulding of the connecting pieces and clips; 
     FIGS. 3 to  5  diagrammatically illustrate the control device of FIG. 2 during different overmoulding operations; 
     FIG. 6 is a longitudinal sectional view of the end of a control device according to the invention, in a first embodiment of the invention; 
     FIG. 7 is a similar view to FIG. 6, in a second embodiment of the invention; 
     FIG. 8 diagrammatically shows the axial connection of the device of FIG. 7 with a support forming part of a motor vehicle; 
     FIG. 9 is a longitudinal sectional view of a support for the radial mounting of the device of FIG. 7; 
     FIG. 10 is a sectional view along line X—X of FIG. 9; 
     FIG. 11 is a perspective view of the end of a remote control device according to the invention; 
     FIG. 12 is a perspective view of a receiver block capable of allowing the radial connection of the clip of FIG. 11; 
     FIG. 13 is a perspective view of another receiver block in a refinement; 
     FIG. 14 shows a perspective view of the other end of the remote control device of FIG. 11; and 
     FIG. 15 is a perspective view of a receiver block capable of permitting the radial connection of the clip of FIG.  14 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is firstly made to FIG. 1, which represents a device  10  provided for the remote control of a flap  12  pivoted around an axis  14  and forming part of a heating and/or air conditioning unit  16  of the passenger compartment of a motor vehicle. The control of the flap is performed from a knob  18  mounted to rotate around an axis  20 . 
     The device  10  comprises a deformable cable  22 , advantageously made of steel, which slides inside a supple sleeve  24 . The cable  22  comprises two ends  26  and  28  which project from respective ends  30  and  32  of the sleeve  24 . The ends  26  and  28  are equipped with respective connecting pieces  34  and  36 . 
     The connecting piece  34  is provided to be connected to the end of a lever  38  which is fixed in rotation with the knob  20 , whereas the connecting piece  36  is provided to be connected to the end of a lever  40  pivoting around the axis  14  and fixed in rotation with the flap  12 . 
     Thus, the operation of the rotary knob  18  in one direction or in the other provokes the rotational displacement of the flap  12 . The latter serves to control the passage of a flow of air in the housing of the unit  16 . 
     The overmoulding of the connecting pieces  34  and  36  and of the clips  42  and  44  is performed in precise conditions, so that the distance A that separates the connecting piece  34  from the end  30  of the sleeve (here defined by the position of the clip  42 ) and so that the distance B that separates the connecting piece  36  from the end  32  of the sleeve  24  (here defined by the position of the clip  44 ) are made with a minimum tolerance. 
     The sum A+B corresponds to the value D of the “functional projection” of the control device  10 . Reference is now made to FIGS. 2 to  5  to describe the positioning of the connecting pieces  34  and  36  and of the clips  42  and  44  by overmoulding. 
     At the outset one provides for (FIG. 2) a remote control comprising the sleeve  24  in which the cable  22  is threaded so that the ends  26  and  28  of the cable project respectively beyond ends  30  and  32  of the sleeve. The ends  26  and  28  of the cable are ended respectively with two protuberances  46  and  48  intended to facilitate the subsequent overmoulding of the connecting pieces  34  and  36 . 
     In a subsequent operation (FIG. 3) one proceeds with the simultaneous overmoulding of the connecting piece  34  around the protuberance  46  and of the clip  42  around the end  30  of the sleeve. This overmoulding is performed simultaneously during a single operation by means of a mould  50  represented diagrammatically. This mould allows the overmoulding of the connecting piece  34  and of the clip  42  with a precise positioning relative to said connecting piece and clip. This enables a distance A to be defined with a minimum tolerance. After unmoulding, the device is returned to be placed in the position of FIG.  4 . 
     Then the end  28  of the cable and the end  32  of the sleeve are placed in the same mould  50 , which allows the overmoulding of the connecting piece  36  and of the clip  44  to be performed during a single operation. There too is produced a precise mutual positioning of the connecting piece and of the clip, which allows a distance B between them to be obtained with a minimum tolerance. 
     Thus, at the end of the operation represented on FIG. 5, a remote control  10  similar to that represented on FIG. 1 is obtained, in which the functional protuberance D (i.e. A+B) has a minimum tolerance. 
     In the above process, the same thermoplastic material is advantageously used for the overmoulding of the two connecting pieces and of the two clips. A thermoplastic material of the filled type is preferably used. By way of example, a polyoxymethylene type or polypropylene type material, filled by talc, for example containing 20% by weight talc, can be used. 
     In a preferred embodiment of the invention, the connecting pieces  34  and  36  are identical and have a shape generated by revolution, advantageously a substantially spherical shape, in relation to the axis of the cable. 
     FIG. 6 shows the connecting piece  34  overmoulded around the protuberance  46  of the cable  12 . 
     The clips  42  and  44  are also advantageously identical. These two clips preferably have a shape generated by revolution, in particular a substantially cylindrical shape, relative to the axis of the sleeve. 
     Thus, when the connecting pieces are identical and the clips  42  are identical, the device is symmetrical. 
     FIG. 6 shows the cylindrical structure of the clip  42  which is associated with the connecting piece  34 . A clip  42  produced in this manner is more particularly suitable for radial mounting on an appropriate support of the vehicle, as will be seen further on. 
     Reference is now made to the embodiment of FIG. 7, in which the connecting pieces  34  and  36  are identical to one another and identical to the embodiment of FIG. 6, and in which the device comprises two identical clips  52 , only one of which is represented, i.e. that provided at the end  30  of the sleeve. This clip  52  comprises a ring  54  having a cylindrical general shape overmoulded tightly around the sleeve, and a split muff  56  which is formed in a single piece with the ring  54  and which is situated on the side of the end of the sleeve. 
     The muff  56  comprises a plurality of axial slots which between them delimit axial lugs  58  ending in respective hooks  60  and capable of radially bending. The hooks  60  are turned outwardly and are provided to allow an axial snapping of the clip  52 , whereas the ring  54  is provided to allow a radial snapping. Thus a same clip  52  may be used as desired in an axial type mounting or in a radial type mounting, as will be seen further on. 
     As can be seen on FIG. 7, the lugs  58  provide, in their position of rest, a gap i between them and the sleeve to allow the radial flexion of the hooks. 
     Reference is now made to FIG. 8 which shows the axial snapping of the clip  52  onto a support  62  with axial attachment. The support  12  forms part of a control panel  64  comprising, for example, a rotary knob  18  similar to that of FIG.  1 . The support  62  comprises an annular ring  66  through which the clip  62  is intended to pass, through which itself the sleeve and the cable pass. The ring  66  delimits an axial passage  68  having a circular cylindrical shape opening respectively into an inlet cone  70  and an outlet cone  72 . The inlet cone  70  facilitates the introduction of the clip  52  in the axial direction of the arrow F 1 , which allows an inward radial deformation of the hook-shaped lugs  58 . After complete introduction, the clip  52  occupies the position represented by broken lines on FIG. 8, in which the hooks  60  are radially outwardly moved apart and rest against the outlet cone  72 , whereas the ring  54  rests on the other side next to the inlet cone  70 . 
     The clip  52  and the support  64  have paired shapes which allow a precise axial retention of the clip in the support. 
     Reference is now made to FIGS. 9 and 10 which represent another support  74  intended for the attachment of the other clip, which is identical to the clip  52  of FIG.  7 . The support  74  is provided, in the example, to form part of the heating and/or air conditioning unit  16 . The support  74  essentially comprises a block of parallelepipedic shape having two opposite walls that respectively delimit two U-shaped receptacles  80  and  82 , these two receptacles being aligned along an axis XX, the receptacle  80  having larger dimensions than receptacle  82 . 
     Provided between the walls  76  and  78  are two opposite deformable lugs  84  and  86  ending respectively in two hooks  88  and  90  that are turned towards one another. The support  74  allows a radial attachment of the clip  52  in the direction of arrow F 2 . During the introduction, the hooks  88  and  90  move apart from one another and then move closer to one another again once the clip  52  is immobilised in the support  74 . 
     Reference is now made to FIG. 11, which is a perspective view corresponding to FIG.  6 . The clip  42 , which has a circular cylindrical shape, is able to be received in the support  74  of FIGS. 9 and 10, which is also represented in perspective in FIG.  12 . 
     The clip  42  may also be received in a support  92  such as that represented in FIG. 13, which comprises two pairs of elastic lugs  94  spaced axially from one another and capable of keeping the sleeve on either side of the clip  42 , said clip being received in a recess  96 , having a paired shape, delimited between the pairs of lugs  94 . 
     Reference is now made to FIG. 14, which shows another clip  98 , having a cylindrical general shape. It is made in a single piece with a snapping member  100  extending in the radial direction. The latter is formed of two hooks  102  that are spaced from one another and turned in opposite directions. 
     This member  100  is capable of being received in a recess  104  having a paired shape which a support  106  has (FIG.  15 ), capable of being fixed to the housing of the unit  16 . Thus, the clips (FIG. 11) and  98  (FIG. 14) are different and are capable of bending radially in respective supports by different means. 
     Of course, the invention is not limited to the embodiments that were previously described by way of example and it extends to other variants. 
     In particular, the device may be used for controlling other equipment of motor vehicles.