Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/24—Drums
  • B29D30/242—Drums for manufacturing substantially cylindrical tyre components without cores or beads, e.g. treads or belts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/24—Drums
  • B29D30/26—Accessories or details, e.g. membranes, transfer rings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/24—Drums
  • B29D30/26—Accessories or details, e.g. membranes, transfer rings
  • B29D2030/2671—Holding the layers, e.g. the webs or the plies, in position onto the drum
  • B29D2030/2685—Holding the layers, e.g. the webs or the plies, in position onto the drum by using mechanical means, e.g. jaws, grippers, pressing bars

Definitions

• the present invention relates to the field of manufacturing tires, in particular pneumatic tires for vehicle wheels.
• the present invention relates more particularly to drums which are used to manufacture an annular tire component by winding on said drum one or more elements which are in the form of a band.
• the present invention is particularly applicable when it is desired to manufacture annular reinforcements, called “frets”, intended to form a strapping belt in the top of a tire for a vehicle wheel, and when the For this purpose, a rubber-based strip is wound on a drum, in several contiguous helical turns (which can for example overlap axially or, on the contrary, be juxtaposed axially without overlapping), which contains continuous reinforcing threads parallel to each other. , arranged in the length direction of said strip.
• a first possible drawback is the relative fragility of the needles.
• a second possible drawback relates to the difficulty of adapting the device to the variety of bandages manufactured, since, depending on the bandage manufactured, and in particular depending on the dimensions of said bandage, one may have to lay strips of very wide widths. various, and/or having to adopt winding starting positions which vary greatly along the axis of the drum, from one tire model to another or from one constituent element to another.
• the objects assigned to the invention therefore aim to remedy the aforementioned drawbacks and to propose a new fixing device making it possible to temporarily and reversibly hold an element constituting a bandage on a manufacturing support such as a drum, fixing device which, while guaranteeing firm and reliable support of the constituent element of the bandage, and while remaining light, compact and inexpensive, presents good versatility allowing it to adapt to a wide variety of bandages and configurations of associated manufacturing.
• a drum for the manufacture of a tire said drum having a central axis and having a radially external surface, called a “receiving surface”, which is extends along and around said central axis and which is intended to receive at least one constituent element of said tire, said drum comprising a fixing device which is intended to maintain said constituent element of the tire on said receiving surface, said drum being characterized in This that the fixing device comprises:
• a clamping jaw which is arranged to adopt a position called “working position”, in which said clamping jaw bears on a radially external face of the constituent element of the tire while an opposite face, forming a face radially internal, said constituent element of the tire rests on the receiving surface, in order to exert on said constituent element of the tire a radial compressive force, called “tightening force", which maintains said constituent element of the tire on said receiving surface ;
• an actuation mechanism which is carried by the base and which connects the clamping jaw to said base, said actuation mechanism being arranged to cause the clamping jaw to execute, relative to the base and therefore relative to on the receiving surface, alternately a first movement, called “engagement movement”, which allows the clamping jaw to be brought from a rest position to the working position, and a second movement, called “engagement movement”. clearance”, which allows the clamping jaw to return to the rest position by moving the clamping jaw away from the working position both according to a radial component, in order to release the clamping force, and according to a axial component, in order to free the axial range which is occupied, on the receiving surface, by the constituent element of the tire.
• the actuation mechanism according to the invention makes it possible to easily clamp the element constituting the bandage by pinching using a clamping jaw which, during the engagement movement, approaches the surface of reception by an approach trajectory comprising a radial component, and which can thus press effectively and stably the constituent element of the tire against the receiving surface of the drum, by applying a clamping force which is radial, and which is therefore oriented substantially in a direction normal to said receiving surface.
• the clamping jaw can thus come into contact with the constituent element of the tire, then intensify the force it exerts on said constituent element of the tire, against the receiving surface which supports said constituent element. bandage, until reaching the intensity of the desired radial tightening force, without risk of causing the element constituting the tire to slide on the receiving surface, relative to the position that one wishes to assign to said element constituting the tire and which typically corresponds to the starting position of the winding.
• the fixing device according to the invention thus makes it possible to achieve reliably, and reproducibly from one bandage constituent element to another, tightening and maintaining both firm and stable.
• this same actuation mechanism makes it possible to precisely define the position and the extent of the zone which is covered, in particular axially, by the clamping jaw when said clamping jaw is in position of work. This ensures in particular that the area covered by the clamping jaw in the working position is sufficiently large to firmly hold the constituent element of the tire on the receiving surface, while being sufficiently restricted so that the clamping jaw does not does not interfere, during the winding of said constituent element of the tire on the drum, with the installation trajectory which is followed by said constituent element of the tire, typically here a helical installation trajectory.
• the fixing device and more particularly the clamping jaw, is advantageously configured so as not to hinder the installation of the constituent element of the bandage, and in particular so as not to find itself stuck under a or several thicknesses of said constituent element of the bandage thus placed.
• the actuation mechanism according to the invention advantageously allows, during the release movement, once the element constituting the tire wound on the drum, to first move the clamping jaw away from the surface receiving at least according to a component of movement which is radial centrifugal, and therefore substantially normal to the receiving surface, which makes it possible to eliminate the tightening by releasing the radial tightening force and to separate the clamping jaw from the constituent element of the bandage while avoiding damaging or accidentally sliding the constituent element of the bandage on the receiving surface.
• This same actuation mechanism also allows, still in the release movement, to retract the clamping jaw axially, advantageously without said clamping jaw rubbing against the constituent element of the bandage, and this in such a way to place said clamping jaw in a rest position which is outside the zone of the receiving surface which is occupied axially by the constituent element of the tire located on the drum.
• the fixing device according to the invention does not hinder the installation and initial attachment of the element constituting the tire on the drum, nor the winding on the drum of said element constituting the tire, nor the removal, after winding, of said constituent element of the bandage.
• the fixing device is easily reconfigurable, and in particular makes it possible to adapt the axial extent of said clamping jaw and/or to adapt the axial stroke and /or radial of the clamping jaw, by a simple change of clamping jaw, depending on the dimensions of the constituent element of the tire, the desired starting position, and where applicable the coverage rate that one wishes to obtain between consecutive turns of said constituent element of the bandage.
• the fixing device thus has a great capacity to adapt to very varied structures and dimensions of bandages.
• Figure IA illustrates, in an overall perspective view, a drum according to the invention which is provided with a fixing device integrated into one of the constituent tiles of said drum, fixing device whose jaw clamping is in the working position and maintains the front end portion of a strip pressed against the receiving surface of said drum, receiving surface which here corresponds to the radially external face of the tile.
• Figure IB is a detailed view in the inset of Figure 1, in the area of the drum which carries the fixing device.
• Figure 2 is a detailed perspective view of the tile of the drum of Figures 1 A and IB, the fixing device of which exerts a substantially radial clamping force on the end portion of the strip by means of its clamping jaw placed in working position.
• Figure 3 is a detailed view, with material cut away, of the tile of Figure 2 showing the actuation mechanism of the fixing device, here an actuation mechanism which comprises an articulated quadrilateral carrying the jaw clamping, with the clamping jaw in the working position.
• an actuation mechanism which comprises an articulated quadrilateral carrying the jaw clamping, with the clamping jaw in the working position.
• Figure 4 is a detailed view, with material cut away, of the tile of Figures 2 and 3 showing the actuation mechanism of the fixing device, the clamping jaw this time being in the rest position.
• Figures 5, 6, 7 and 8 illustrate, according to detailed sectional views in a radial plane containing the central axis of the drum, the fixing device and its actuation mechanism in different successive phases of the movement of clearance, Figure 5 corresponding to the working position, Figure 8 to the rest position, and Figures 6 and 7 to a first intermediate position and a second intermediate position.
• the present invention relates to a drum 1 for manufacturing a tire.
• the tire may preferably be a tire intended to equip a vehicle wheel, and more particularly a pneumatic tire.
• the invention can also be used to manufacture tires of other nature, such as for example caterpillars, belts or even conveyor belts.
• the drum 1 has a central axis ZI and has a radially external surface 2, called a “receiving surface” 2, which extends along and around said central axis. ZI and which is intended to receive at least one element 3 constituting said bandage.
• the receiving surface 2 substantially has a shape of revolution around central axis Zl, preferably a straight cylindrical shape (the generators of which are straight lines parallel to central axis Zl), or, even more preferably, a slightly convex shape , barrel-shaped (whose generators are curved and concave in relation to the central axis Zl, in order to be convex outwards).
• axial we designate a direction which is parallel to the axis considered, here more particularly a direction parallel to the central axis Zl of the drum.
• radial we designate a direction which is perpendicular to the axis considered, here more particularly a direction Y1 which is perpendicular to the central axis Zl of the drum or, if necessary, by equivalence, a direction which is normal to the reception surface 2 at the point considered.
• circumferential we designate a direction which is orthoradial, that is to say a direction which, at a point considered, is normal to the radial plane which contains Tax considered and which passes through said point considered. More particularly, we will consider here a circumferential direction XI which is normal, at the point considered, to the radial plane which contains central axis Zl of the drum 1 and which passes through the point considered. The circumferential direction is therefore contained in a plane normal to the axis considered, and, in this plane normal to the axis considered, is perpendicular to the radius which joins said axis considered to the point considered.
• the constituent element of the tire 3 is preferably a strip 4, which, when said constituent element of the tire 3 reaches the receiving surface 2, extends in length substantially in a circumferential direction XI tangent to the receiving surface 2, in width W3 substantially in the axial direction defined by central axis Zl of the drum, and in thickness E3 in the radial direction Yl.
• the constituent element of the bandage 3, and more particularly said strip 4 preferably contains reinforcing threads which extend continuously in the direction of the length of said constituent element of the bandage 3, parallel to each other and parallel to the lateral edges of said constituent element of the tire 3. These reinforcing wires have the function of making the constituent element of the tire 3 almost inextensible in longitudinal traction.
• These reinforcing threads can be made of any suitable material, for example metallic, or of polymer (for example aramid), of natural textile fibers, or even of glass fibers.
• These reinforcing wires can be integrated into a matrix made of any suitable material.
• the metal reinforcing wires or the polymer reinforcing wires can preferably be embedded in a rubber-based matrix.
• the drum 1 is mounted to rotate around its axis Zl, so that the rotation of said drum 1, and therefore of its receiving surface 2, makes it possible to wind the element constituting the tire 3 on the receiving surface 2, in one or more turns around the central axis Zl, in such a way that an annular block is formed with said constituent element of the tire 3.
• the drum 1 comprises a fixing device 5 which is intended to hold the constituent element of the tire 3 on the receiving surface 2.
• the fixing device 5 is intended to ensure temporary and reversible fixing of the constituent element of the bandage 3 on the receiving surface 2, in particular at the start of the winding operation, and more preferably throughout the duration. of the winding operation. Once the winding operation is completed, the fixing device 5 is designed to be able to release the constituent element of the bandage 3, and more generally the annular block which will result from the winding operation.
• the fixing device 5 is more particularly intended to maintain a front end portion 3F of the element constituting the tire 3 in a zone of the surface reception 2 which corresponds to the starting position from which it is desired to wind the constituent element of the tire 3 on the drum 1.
• the aforementioned front end portion 3F advantageously corresponds to the front end of the strip 4.
• the fixing device 5 comprises a base 6 which is fixed to the drum 1, so that the fixing device 5 is carried by said drum 1.
• the fixing device 5 is thus on board the drum 1, and permanently coupled to the receiving surface 2, as long as the base 6 remains fixed on the drum 1.
• the fixing device 5 is therefore spontaneously integral with the movements of the drum 1, and more particularly with the movements of the receiving surface 2, here the rotating movements of the receiving surface 2 around the central axis Zl.
• said fixing device 5 does not require additional equipment distinct from the drum 1 to bring said fixing device 5 closer to the drum 1, properly position the fixing device 5 relative to the drum, then drive said fixing device fixation 5 in synchronous rotation with the drum 1 around the central axis Zl.
• the fixing of the base 6 on the drum is advantageously reversible, so as to allow the dismantling of the fixing device 5 for its maintenance or replacement.
• This fixing can be carried out for example by means of screws.
• the base 6 notably allows the fixing device 5 to remain fixed on the drum 1, and therefore coupled to the receiving surface 2, without interrupting an operation of winding an element constituting a tire 3 to another operation of winding an element constituting a bandage 3.
• the base 6 allows in particular the fixing device 5 to remain fixed on the same drum 1 while said drum 1 is transferred, if necessary, between several successive manufacturing stations, which make it possible to successively install on said drum 1, and in particular to stack in successive layers on said drum 1, several elements 3 constituting the same tire.
• the base 6 also allows the fixing device 5 to remain fixed on the same drum 1 without interruption during several manufacturing cycles consecutive during which said same drum 1 is reused at each manufacturing cycle in order to manufacture several distinct successive tires on said drum 1.
• the fixing device 5 also comprises a clamping jaw 7 which is arranged to adopt a position PI called the “working position” PI, in which, as is visible in Figures IA, IB, 2 and 5, said clamping jaw 7 bears on a radially external face 3_out of the element 3 constituting the tire while an opposite face, forming a radially internal face 3_in, of said element 3 constituting the tire rests on the receiving surface 2, in order to exert on said element 3 constituting the bandage a radial compressive force F clamp, called “tightening force” F clamp, which maintains said element 3 constituting the bandage on said receiving surface 2.
• a radial compressive force F clamp called “tightening force” F clamp
• the clamping jaw 7 thus ensures stable holding of the constituent element of the tire 3 by pinching against the receiving surface 2. This allows the winding operation to begin, and more particularly allows the receiving surface 2 to rotate around the central axis ZI and to drive following it, by circumferential traction, the constituent element of the tire 3, without risk that said constituent element of the tire 3 does not moves on the receiving surface 2 relative to its desired starting position or accidentally detaches from the receiving surface 2.
• the constituent element of the bandage 3 is compressed by the clamping force F clamp in the direction of its thickness E3, thickness E3 which here corresponds to the distance separating the radially internal face 3_in of the radially external face 3_out of said element 3, and which also preferably corresponds to the smallest dimension of said constituent element of the tire 3.
• the front end portion 3F of the constituent element of the bandage 3, here more particularly of the band 4 may have a straight front, that is to say a front which extends perpendicularly at the two edges of element 3, here of strip 4, or else a beveled front which extends obliquely from one edge to the other, thus forming an angle, and therefore a point, relative to the one of the edges of element 3, here one of the edges of strip 4.
• the fixing device 5 according to the invention is particularly well suited to holding strips 4 having a frontal bevel, due to the fact that said fixing device 5 is capable of ensuring a good grip on the strip 4, even if the radially external face 3_out of said strip 4 has a restricted surface area due to the presence of said bevel.
• the fixing device 5 further comprises an actuation mechanism 10, which is carried by the base 6 and which connects the clamping jaw 7 to said base 6, said actuation mechanism 10 being arranged to execute to the clamping jaw 7, relative to the base 6 and therefore relative to the receiving surface 2, alternatively:
• engagement movement FWD a first movement FWD, called “engagement movement” FWD, which allows the clamping jaw 7 to be brought from a rest position PO to the working position PI
• release movement BWD a second movement BWD, called "release movement" BWD, which makes it possible to return the clamping jaw 7 to the rest position PO by moving the clamping jaw 7 away from the working position PI at the same time according to a radial component BWD R1, here a centrifugal radial component, in order to release the clamping force F clamp, and according to an axial component BWD A, in order to release the axial range 11 which is occupied, on the receiving surface 2, by the constituent element of the bandage 3.
• a radial component BWD R1 here a centrifugal radial component
• the clamping jaw 7 is therefore a mobile jaw placed under the control of the actuation mechanism 10.
• the release movement BWD makes it possible to completely free the space located at the radial plumb of said strip 4, and more generally at the radial plumb of said reinforcing belt, which frees access for the installation of another constituent element 3, such as a tread, which is superimposed on said reinforcing belt.
• the trajectory T7 of the clamping jaw 7 during the clearance movement BWD is curved, so as to combine with an axial component BWD A first of all a first radial component BWD R1 (figure 6) according to which the bit of clamping 7 moves away from the central axis ZI of the drum, in order to detach itself from the element constituting the tire 3, without rubbing on the radially external face 3_out of said element 3, then a second radial component BWD R2 according to which the jaw clamping moves closer to the central axis ZI in order to reach the rest position PO (figure 8).
• the trajectory T7 of the clamping jaw 7 during the clearance movement B WD presents, in a radial reference plane containing the central axis ZI of the drum 1, a concave, quasi-parabolic shape, relative to the central axis ZI of the drum.
• such a concave trajectory T7 makes it possible to reach a rest position PO in which the clamping jaw 7 projects little or not at all radially relative to the receiving surface 2.
• said clamping jaw 7 when the clamping jaw 7 is in the rest position PO, said clamping jaw 7 remains contained inside a fictitious envelope which is centered on the central axis ZI and whose radius, considered in a plane normal to the central axis Zl, is obtained by applying to the radius of the receiving surface 2, considered in said plane normal to the central axis Zl, a transformation by a scaling centered on the central axis Zl and whose homothetic ratio is equal to or less than 105%, preferably equal to or less than 102%, or even preferably equal to or less than 101%, possibly equal to or less than 100.5%.
• Said fictitious envelope therefore has the same general shape as the real receiving surface 2 (for example a straight cylinder, or a slightly convex barrel shape), but with a radius, or rays if the radius varies along the axis. central Zl, which is slightly greater than the corresponding radius, or corresponding radii, of the receiving surface 2.
• the thickness according to which the clamping jaw 7, in the rest position PO, possibly projects radially beyond the receiving surface 2 represents less than 5%, preferably less than 2 %, or even less than 1%, possibly less than 0.5% of the radius of the reception surface 2 at the abscissa considered along the central axis Zl.
• the radial extra thickness provided by the clamping jaw 7, in the rest position PO, relative to the receiving surface 2 is preferably equal to or less than 4 mm, 3 mm or even 1, 5mm.
• the radius of the receiving surface 2 can for its part be comprised for example between 300 mm and 400 mm, and in particular equal to 350 mm +/- 20 mm, in particular in the zone occupied by the clamping jaw 7 in PO rest position.
• this allows the fixing device 5 to remain compact and discreet, and prevents the clamping jaw 7, when it is in the rest position PO, from hindering access to the receiving surface 2 or creates on the drum 1 an unbalance or a protruding obstacle which could interfere with an object external to the drum 1 during the rotation of the receiving surface 2.
• Such an arrangement makes it possible in particular, after having placed on the drum 1 a first constituent element of the bandage 3 forming a reinforcing belt, then retracting the clamping jaw 7 into the rest position PO, to safely place a band rolling, forming a second constituent element of the tire, over said reinforcing belt.
• the engagement movement FWD which makes it possible to move from the rest position PO to the working position PI is preferably carried out along the same spatial trajectory T7 as the release movement BWD, simply by traveling said trajectory T7 in reverse.
• the FWD engagement movement thus also comprises at least one centripetal FWD R2 radial component, particularly in the final phase of the FWD engagement movement.
• the engagement movement FWD follows a concave, quasi-parabolic trajectory T7, then said engagement movement FWD will comprise, in combination with an axial component FWD A which axially brings the clamping jaw closer to the desired zone on the receiving surface 2, a first centrifugal radial component FWD R1, in the initial phase of the FWD engagement movement, then a second centripetal FWD R2 radial component in the final phase of said FWD engagement movement.
• the drum 1 is subdivided into a plurality of tiles 12 which are distributed in azimuth around the central axis ZI so as to form, as a whole, the receiving surface 2.
• such tiles 12 can have edges forming combs, so as to be able to fit into each other, from such that said tiles 12 ensure the continuity of the receiving surface on the circumference of the drum 1 while having relative mobility between neighboring tiles.
• this relative circumferential mobility in combination with a radial expansion/retraction mechanism, makes it possible to modify the radial position of said tiles 12, and consequently the diameter of the drum 1, and more particularly the diameter and therefore the circumference of the receiving surface 2, and consequently the winding diameter of the constituent element of the tire 3, depending on the dimensions of the tire to be manufactured.
• the fixing device 5 is integrated into one of said tiles 12.
• the base 6 can be fixed, reversibly, for example by screwing, in a housing 13 which is hollowed out on the radially internal face of the tile 12, while the radially external face of said tile 12 forms a portion of the receiving surface 2.
• At least part of the actuation mechanism 10 is preferably contained in said housing 13, set back radially from the receiving surface 2.
• the fixing device 5 is thus particularly compact, since said fixing device 5 is at least partly contained in the (radial) thickness of the tile 12 itself, and more generally at least in part, or even in almost entirely, contained inside the envelope which radially delimits the receiving surface 2 around the central axis Z 1.
• the fixing device 5 is located on the axially external lateral edge of the tile 12, that is to say on the free edge of the tile 12, which corresponds to the edge of said tile 12 which is the further away axially from the so-called “equatorial plane” PE of the drum.
• the fixing device 5 does not encumber the receiving surface 2 and can easily retract the jaw clamp 7 in a rest position PO which is located at a free axial end of the receiving surface 2, axially away from the central zone of said receiving surface 2.
• the clamping jaw 7 when it is in the rest position PO, the clamping jaw 7 remains contained axially in the overall axial range occupied by the drum 1, and more particularly in the overall axial range occupied by the receiving surface 2, so that said clamping jaw 7 does not form an axial projection with respect to the lateral edges of the drum 1, and more particularly with respect to the receiving surface 2, and in particular with respect to the axially most external edge of the tile 12 which carries said fixing device 5.
• said fixing device 5 has good compactness, and reliable and safe operation, in that it does not risk, during the rotational movement of said drum 1 around the central axis Zl, of colliding with an object which would be axially close to the drum 1.
• the actuation mechanism 10 comprises, such as that is clearly visible in Figures 3 to 8, an articulated quadrilateral 20 of which a first vertex and a second vertex are formed respectively by a first pivot 21 belonging to the base 6 and by a second pivot 22 belonging to the base 6, and of which a third vertex and a fourth vertex are formed respectively by a third pivot 23 and by a fourth pivot 24 which both belong to a platform 25 which carries the clamping jaw 7.
• the base 6 In a frame of reference attached to the base 6, and therefore attached to the receiving surface 2, the base 6 therefore forms a fixed base, and the platform 25 a mobile platform 25 designed to alternately reach d 'on the one hand a first position (figure 4, figure 8), which corresponds to a position in which the clamping jaw 7 fixed on said platform 25 is in the rest position PO, and on the other hand a second position ( Figure 3, Figure 5) in which the clamping jaw 7 fixed on the platform 25 is in the working position PI.
• a first position (figure 4, figure 8)
• Figure 3, Figure 5 in which the clamping jaw 7 fixed on the platform 25 is in the working position PI.
• an articulated quadrilateral structure 20 according to the invention is particularly simple and robust, and makes it possible to give the clamping jaw 7 a concave, quasi-parabolic trajectory T7, which provides the advantages described above.
• the axes Z21, Z22, Z23, Z24 of the first, second, third and fourth pivots 21, 22, 23, 24 are all normal to the same radial reference plane, called the “sagittal plane” PS, which contains the central axis ZI of the drum 1 and which subdivides the drum 1 into two parts substantially symmetrical to each other.
• said sagittal plane PS preferably corresponds to the radial plane which contains on the one hand the central axis ZI and on the other hand the radius perpendicular to the central axis ZI and which corresponds to the bisector which divides into two angular sub-sectors equal to the angular sector that the tile 12 covers, in azimuth, around the central axis Zl.
• first, second, third and fourth pivots 21, 22, 23, 24 are advantageously distinct from each other and not coaxial with each other, so that the vertices of the articulated quadrilateral 20 are distinct and distant from each other.
• first pivot 21 is radially closer to the central axis Zl than the third pivot 23 and that, likewise, the second pivot 22 is radially closer close to the central axis ZI than the fourth pivot 24.
• the first pivot 21 is here also radially closer to the central axis ZI than the second pivot 22.
• the platform 25 is preferably connected to the base 6 by means of a first arm 26 which connects the first pivot 21 to the third pivot 23, thus defining a first side 26A of the articulated quadrilateral 20, and on the other hand a second arm 27 which connects the second pivot 22 to the fourth pivot 24, thus defining a second side 27A of the articulated quadrilateral 20.
• first side 26 A the straight line segment which, geometrically, joins the first pivot 21 to the third pivot 23, and more particularly the line segment which is perpendicular and secant to the axes Z21 of the first pivot 21 and Z23 of the third pivot 23 and which thus joins, in the aforementioned sagittal plane PS, the center of rotation from the first pivot 21 to the center of rotation of the third pivot 23, that is to say which joins the first vertex of the articulated quadrilateral 20 to the third vertex of the articulated quadrilateral 20.
• second side 27A the straight line segment which, whatever the material shape of the second arm 27, geometrically joins the second vertex of the articulated parallelogram 20, therefore the center of rotation of the second pivot 22 , at the fourth vertex of the articulated parallelogram 20 formed by the center of rotation of the fourth pivot 24.
• first arm 26 respectively the shape of the second arm 27, can vary without departing from the scope of the invention.
• first arm 26 and the second arm 27 will preferably be rectilinear.
• the first arm is formed by a link, or a pair of links parallel to each other, which each connect the first pivot 21 to the third pivot 23.
• the second arm 27 is formed by a link, or a pair of rods parallel to each other, which each connect the second pivot 22 to the fourth pivot 24.
• the housing 13, hollowed out in the tile 12 to accommodate the base 6 and at least part of the actuation mechanism 10, will preferably pass through so as to open onto the outer radial face of the tile 12, in order to allow the passage of the first and second arms 2627 as well as the stroke of said arms 26, 27 and of the platform 25 during the FWD engagement and BWD release movements.
• the housing 13 will thus form a notch cut in the axially most external edge of the tile 12.
• the fixing device 5 will preferably be arranged in such a way that, both in the rest position PO and in the working position PI, the first and second arms 26, 27, as well as the radially surface the outermost of the platform 25, on which the clamping jaw 7 is fixed, are located radially set back from the radially external face of the tile 12, that is to say are closer to the central axis ZI as the radially external face of the tile 12, so as to fit in with respect to the apparent surface of said tile 12 and to the receiving surface 2.
• this arrangement will contribute to the compactness of the fixing device 5.
• the first arm 26 gives the first side 26 A a fixed length L26A, that is to say establishes an invariant distance between the first pivot 21 and the third pivot 23, that is to say that said first arm 26 maintains a center distance of constant value between the first pivot 21 and the third pivot 23.
• L26A the length of the first side 26 A will be constant during the FWD engagement then BWD disengagement movements.
• the first arm 26 may for example have a telescopic structure, of adjustable length, lockable to the desired length by any means such as a screw.
• the second arm 27 which will define a length L27A of the second side 27 A, that is to say the center distance separating the second pivot 22 from the fourth pivot 24, which will be fixed, possibly adjustable by an adjustment system.
• Such an adjustment system will, among other things, advantageously allow the working position PI to be adapted as a function of the thickness E3 of the tire constituent element 3 which it is desired to maintain by clamping on the receiving surface 2.
• the length of the second side L27A that is to say, as indicated above, the distance which separates the axis Z24 of the fourth pivot 24 from the axis Z22 of the second pivot 22 , is smaller than the length of the first side L26A, that is to say, as indicated above, the distance which separates the axis of the third pivot 23 from the axis of the first pivot 21:
• the second arm 27 is shorter than the first arm 26.
• the articulated quadrilateral 20 forms a “false parallelogram”, which advantageously makes it possible to combine with the generally parabolic trajectory T7 mentioned above, during the movement of clearance BWD, a tilting component BWD P of the clamping jaw 7, in pitch around the circumferential direction XI.
• This tilting in pitch BWD P which occurs from the start of the release movement BWD, advantageously allows the clamping jaw 7 to be removed from the radially external face 3_out of the constituent element of the tire 3 resting on the surface of reception 2 without the clamping jaw 7 exerting friction, and therefore axial traction, on said constituent element of the tire 3.
• Such an arrangement using arms 26, 27 of different lengths also has the advantage of accentuating the radial character of the approach orientation during the final phase of the FWD engagement movement, and thus promotes the generation of a high intensity radial clamping force F clamp.
• the shortest arm here the second arm 27, and therefore the second and fourth pivots 22, 24, are closer axially to the portion of the receiving surface 2 which receives the constituent element of the tire 3 as the longest arm, here the first arm 26, and the first and third pivots 21, 23.
• first and third pivot 21, 23, as well as the first arm 26 (long arm), are therefore axially further away from the equatorial plane PE of the drum 1 than are, on the same side of said equatorial plane PE, the second and fourth pivots 22, 24 and the second arm 27 (short arm).
• the actuation mechanism 10 can be powered by any type of motor, electric, pneumatic, or hydraulic.
• the actuating mechanism 10 is moved by a cylinder 30, for example a double-acting pneumatic cylinder, the body 31 of which is carried by the base 6 and the rod 32 of which engages on the first arm 26, at the level of a fifth pivot 33 by which said rod 32 is articulated on said first arm 26.
• This fifth pivot 33 is located between the first pivot 21 and the third pivot 23, at a distance from each of said first and third pivots 21, 23.
• the axis Z33 of this fifth pivot 33 is also parallel to the axes Z21, Z22, Z23, Z24 of the first, second, third and fourth pivots 21, 22, 23, 24.
• such a very compact arrangement allows the jack 30 to cause the tilting of the first arm 26, and therefore the deformation of the articulated quadrilateral 20 and consequently the movement of the platform 25 and the clamping jaw 7 , alternately in a direction corresponding to the FWD engagement movement, here, in Figures 5 to 8, by tilting the first arm 26 clockwise, retracting the rod 32 in the body 31 towards the right, then in an opposite direction corresponding to the release movement BWD, here, in Figures 5 to 8, by tilting the first arm 6 in the counterclockwise direction, deploying the rod 32 out of the body 31 to the left.
• the fifth pivot 33 is radially further away from the central axis ZI than the first pivot 21, and radially closer to said central axis ZI than the second pivot 22.
• the body 31 of the cylinder 30 is articulated on the base 6 at the level of a sixth pivot 34, the axis Z34 of which is parallel to the axis Z33 of the fifth pivot 33.
• the jack 30 is preferably arranged substantially parallel to the central axis Zl, in the housing 13, facing the radially internal face of the tile 32, so that the direction of movement in translation of the rod 32 is parallel to the central axis Zl at +/- 10 degrees.
• the sixth pivot 34 is, for this purpose, preferably located axially closer to the equatorial plane PE as the fifth pivot 33. Such an arrangement makes it possible to reconcile compactness and power of the actuation mechanism 10.
• the fixing device 5 which can constitute an invention in its own right, adaptable to different types of actuation mechanisms 10, including of course the actuation mechanism 10 with an articulated quadrilateral 20 described below above, and/or adaptable to different types of tire manufacturing support, whether said support is a drum 1 or other, the clamping jaw 7 is formed, as is clearly visible in Figures 3 and 4, by a blade -spring 40, which is arranged so as to be able to flex elastically under the stress of the clamping force F clamp.
• the clamping jaw 7 is not only simple, light, compact and robust, but it also has flexibility ("compliance", in English) which allows it to flex elastically in contact with the constituent element of the bandage 3, against the resistance opposed by the underlying receiving surface 2, under the tightening force F clamp.
• the leaf spring 40 is advantageously mounted flat on the platform 25, so that the thickness E40 of said leaf spring 40 is oriented in a radial direction Y1 (here the radial direction Y1 which, with the central axis Zl, generates the sagittal plane PS mentioned above), in order to allow a bending which has the effect of curving the leaf spring 40 around the circumferential direction XI, that is to say a bending which results from a bending moment which is carried by said circumferential direction XL
• the leaf spring 40 could be made of steel, in particular a spring steel containing silicon, or even an aluminum-based alloy, or even a composite material.
• the face of the leaf spring 40 here the radially internal face of said leaf spring 40, intended to come into contact with the constituent element of the tire 3, here therefore intended to come into contact with the radial face externally 3_out of said constituent element of the bandage 3, may be coated with a non-adhesive material, such as Xylan®.
• the leaf spring 40 may have a thickness of between 0.5 mm and 3 mm, for example between 1 mm and 2 mm.
• the small thickness of the leaf spring 40 limits the radial height of the possible projection that said leaf spring 40 forms on the receiving surface 2 in the working position 1P1 and thus allows an applicator roller, intended to apply the constituent element of the tire 3 on the drum 1, to roll on the receiving surface 2 in the circumferential direction XI and to cross the location occupied by the leaf spring 40, and therefore to cross said jump, in passing partly over the leaf spring 40, without damage to said applicator roller, nor to the constituent element of the bandage 3, nor to the leaf spring 40.
• the leaf spring 40 is mounted cantilevered so as to present on the one hand a captive portion 40A , fixed in support on the platform 25, and on the other hand a free end portion 40B which projects axially with respect to the platform 25 so as to be able to come into contact with the constituent element of the tire 3 when the clamping jaw 7 is brought to the working position PI.
• a captive portion 40A fixed in support on the platform 25, and on the other hand a free end portion 40B which projects axially with respect to the platform 25 so as to be able to come into contact with the constituent element of the tire 3 when the clamping jaw 7 is brought to the working position PI.
• the leaf spring 40 comprises at least one slot 41 which extends axially over a portion of the length of said leaf spring 40 so as to subdivide said leaf spring 40 into at least two tongues 42, 43 which are each intended to come into contact with the constituent element of the tire 3 when the clamping jaw 7 is in the working position PI, and which each occupy a sector different angular around the central axis Zl.
• the subdivision into tongues 42, 43 makes it possible to reduce the rigidity, and therefore to increase the flexibility, of the leaf spring 40, while maintaining a thickness E40 sufficiently large to allow the leaf spring to resist to plasticization under the clamping force F clamp, that is to say to allow the leaf spring 40 not to undergo irreversible plastic deformation when said leaf spring 40 is pressed against the constituent element of the tire 3.
• each tongue 42, 43 makes it possible to dedicate each of said tongues 42, 43 to a specific angular sector around the central axis Zl, each tongue 42, 43 thus generating its own support on the constituent element of the bandage 3, independently of the other tongue 43, 42, which allows the clamping jaw 7, here the leaf spring 40, to better match, by double support, the curvature of the drum 1, considered in a plane normal to the central axis Zl.
• the slot 41 extends axially to the axial end of the free end portion 40B of the leaf spring 40.
• the at least two tabs 42, 43 thus form terminal tabs 42, 43 of which the respective axial ends are free, and in particular free to flex independently of one another.
• the at least two tongues 42, 43 form the free end portion 40B, while they are attached to, and in this case formed in one piece with, the same common root which in turn forms the captive portion 40A fixed to the platform 25.
• the invention also relates as such to an installation 50 for manufacturing a bandage comprising:
• drum 1 being mounted to rotate relative to the frame 51 so as to be able to rotate on itself around its central axis Zl,
• At least one supply system 52 arranged to convey to the drum 1 an element constituting the tire 3 which is in the form of a strip 4, so that the front end portion can be fixed 3F of the strip 4 delivered by the supply system 52 on the receiving surface 2 of the drum 1 by means of the fixing device 5, then wind said strip 4 over at least one complete turn, and preferably over several complete turns, around the central axis Z 1, on the receiving surface 2, by rotating the drum 1 around its central axis Zl.
• the supply system 52 can be formed for example by a reel which receives a reel where the strip 4 is stored, which is then unwound from said reel as said strip is wound onto the drum 1, or else by a calender which continuously produces the strip 4, in the desired quantity, by passing simultaneously between two rollers, which define an air gap corresponding to the thickness E3 of the strip 4, reinforcing wires as well as two fine layers of rubber which sandwich said reinforcing wires.
• the supply system 52 may include guiding and installation members (not shown), in particular an applicator roller, which make it possible to guide the strip 4 and apply said strip 4 to the surface. reception 2 of drum 1.
• leaf springs 40 are slotted to present tongues 42, 43 as described above.
• the invention also relates to a method of manufacturing a tire during which a front end portion 3F of an element 3 constituting the tire 3, here a band 4, is held on a drum 1 according to the invention, by means of the fixing device 5 carried by said drum 1, while said element 3 constituting the tire, here the band 4, is wound on said drum 1.
• the constituent element of the bandage 3, here the band 4 is wound from the front end portion 3F of said constituent element of the bandage which forms the starting point of a first turn, in several consecutive helical turns, including at least one second turn which follows the first turn.
• Said consecutive helical turns are offset axially relative to each other, so that said turns do not overlap, axially, the front end portion 3F of the constituent element of the tire 3, or, all at most, only partially overlap, axially, said front end portion 3F.
• the size of the clamping jaw 7 is chosen, here the axial length of the leaf spring 40, in such a way that, when said clamping jaw 7 is in the working position PI to maintain the front end portion 3F on the receiving surface 2 of the drum 1, the clamping jaw 7 is interrupted axially before the axial range which is occupied by the second turn and the following turns, so that no turn comes to cover and trap said clamping jaw 7.
• the clamping jaw 7, here the leaf spring 40 is in no way trapped by the turns of the constituent element of the bandage 3, since said clamping jaw 7 is placed on the first turn but is interrupts axially before the edge of the second turn, the clamping jaw 7 can then be removed, in order to make it leave its working position PI and return it to its rest position PO, without disturbing or damaging the annular block formed by all of said turns.
• the supply system 52 delivers at least part of the strip 4, the front end portion of which 3F is applied to the receiving surface 2, in the position of desired departure.
• This starting position is such that it overlaps at least partly the working position PI such that this working position is defined by the range of travel of the actuating mechanism 10 of the fixing system 5 and by the dimensions of the leaf spring 40 chosen.
• This forced tilting of the first arm 26 induces a deformation of the articulated quadrilateral 20 around its pivots 21, 22, 23, 24, and is thus converted into a concave, quasi-parabolic curved movement of the platform 25 and therefore of the leaf spring 40 carried by said platform 25, relative to the central axis Zl.
• the actuation mechanism 10 is arranged such that, at this apogee, the first arm 26 and the second arm 27 are both, simultaneously, radially taut, that is to say that the third pivot 23 is located at the radial plumb of the first pivot 21 and the fourth pivot 24 is at the radial plumb of the second pivot 22.
• This choice of configuration at the apogee of the trajectory T7 which corresponds substantially to a position located halfway between the rest position PO and the working position PI, makes it possible in particular to maintain a relative parallelism between the leaf spring 40 and the receiving surface 2 in each of the two useful extremal positions of the trajectory T7, namely the rest position PO and the work position PI.
• the engagement movement FWD continues with a descending phase of the quasi-parabolic trajectory T7, combining an axial component FWD A directed towards the equatorial plane PE and a second radial component FWD R2, this time centripetal, which allows the leaf spring 40 to fall back towards the central axis Zl and therefore towards the receiving surface 2, and thus to gradually approach the strip 4 (figure 6), and more precisely the radially external face 3_out of said strip 4, until reaching the working position PI, in which said leaf spring 40 finds itself resting against said strip 4 (figure 5).
• the traction exerted on the rod 32 of the cylinder 30 then results in a substantially radial clamping force F clamp, which presses the strip 4 against the receiving surface 2, at the desired location to form the starting point of winding.
• the difference in length between the first arm 26 and the second arm 27 creates, during the descending phase of the engagement movement FWD, a tilting in pitch FWD P of the leaf spring 40, here in a clockwise direction around the circumferential direction 40 on the radially external face 3_out of the strip 4 in a quasi-radial direction, and therefore quasi-normal to the receiving surface 2, without generating unwanted axial movement of said strip 4 on the receiving surface 2.
• the flexibility of the leaf spring 40 allows said leaf spring 40 to deform elastically in contact with the strip 4 supported by the receiving surface 2, and thus to flexibly adapt the force of tightening F clamp and the distribution of the tightening according to the geometry and dimensions of the drum 1 and the band 4.
• the fixing device 5 is driven integrally with the drum 1 in this rotational movement, and, due to the fact that said fixing device 5 firmly holds the strip 4 in the chosen position on the circumference of the drum 1, the strip 4 is driven, by longitudinal traction, in the circumferential direction XI, and therefore begins to wind up on the drum 1.
• this rotation of the drum 1 is accompanied by a relative axial movement of the supply system 52, and more particularly of the applicator roller, relative to the drum 1, parallel to the central axis Zl, in order to generate a helical winding, on several turns, having the desired pitch.
• the rotation of the drum 1 is stopped, then the fixing device 5 is activated again, this time to release the strip 4, by operating the release movement BWD .
• the rod 32 of the cylinder 30 is deployed to tilt the first arm 26 in the opposite direction to the direction previously used for the FWD engagement movement, here therefore in an anti-clockwise direction on Figures 6 to 8.
• the return trajectory T7 corresponding to the release movement BWD is identical to that of the engagement movement FWD, but is traveled in the opposite direction.
• This recoil trajectory T7 then comprises, once the apogee has passed (figure 7), a descending phase (figures 7 and 8), which combines an axial recoil component BWD A and a second radial component BWD R2 this time centripetal radial, and which allows the leaf spring to return to the folded position against the tile 12, in its rest position PO (figure 8).
• the installation 50 thus offers a clear field for accessing the receiving surface 2 carrying the rolled up strip 4, or so that another bandage constituent element 3 can be placed on top of said rolled up strip 4. , or so that the annular block thus formed by said wound strip 4 is removed from the drum 1.
• a fixing device 5 comprising an articulated quadrilateral 20, carried by a base 6, as well as a leaf spring 40, in particular with a leaf spring 40 split, regardless of the manufacturing support for which said fixing device 5 is intended, and on which it is fixed.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Tyre Moulding (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=84359708

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• 2022
  • 2022-09-27 FR FR2209800A patent/FR3140010B1/fr active Active
• 2023
  • 2023-09-14 CN CN202380068612.1A patent/CN119923315A/zh active Pending
  • 2023-09-14 EP EP23769250.4A patent/EP4594091A1/de active Pending
  • 2023-09-14 WO PCT/EP2023/075240 patent/WO2024068285A1/fr not_active Ceased

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