MXPA97004678A - Prefor support device - Google Patents

Abstract

The present invention relates to a preform support device (1) designed to be combined with a multiplicity of analogous devices coupled together one after the other in an endless chain to transfer preforms with simultaneous rotation thereof on themselves, the device it comprises: a) a platen (2) provided with means for articulately coupling to two adjacent platens that are respectively located front and back with respect to a direction (3) of movement of the chain, b) a body (4) fixed on the plate, and c) a rod (5) supported by the body so that it freely rotates with the possibility of axial movement, the rod has a clamping end (7) shaped to be removably attached to the open end of a preform (8). d) the coupling means including, at a first end of the plate, a joining glue (11) supporting a coupling head in the form of a spherical cap (12) intended to rest on an adjacent platen located on the side of the first end, and at a second end, a seat (13) in the form of a spherical zone having a shape complementary to the coupling head and provided with a central axial opening (14) for the free passage of the joining tail of the adjacent stage located on the side of the second end, e) where: i) the spherical cap-shaped coupling head is supported so that it freely rotates in the joining glue, ii) a support plate (16) is clamped, through clamping means, to a free end of the joining glue, to the bearing plate extending transversely to the joining glue and substantially parallel to a face of the coupling head opposite a spherical cap-shaped face; and iii) an annular bearing (17) is interposed coaxially with the connecting tail between the mutually facing faces of the coupling head and the plate. apo

Description

PREFORM SUPPORT DEVICE The present invention relates to improvements provided to the preform support devices arranged to be associated with a multiplicity of analogous devices coupled with articulations one after the other in an endless transfer chain of preforms with simultaneous rotation thereof on them, each device has: a plate provided with means of coupling with articulation with two other adjacent plates located respectively front and back (in the direction of movement of the chain), • - a fixed body on said plate; and a rod supported by said free-rotating body with the possibility of axial displacement, said rod has a clamping end shaped to be movably secured with the open end of a preform; the coupling means have: at a first end of the plate, a joining glue supporting a spherical cap coupling head adapted to rest on the adjacent plate located next to this first end, and at a second end, a seat in the form of a spherical zone of complementary shape to that of the cap and provided with a central axial opening for the free passage of the joining tail of the adjacent stage located next to this second end. A chain of transfer of preforms constituted by such devices is found especially in facilities for the manufacture of containers, such as bottles, flasks or the like, made of a plastic material, especially a thermoplastic material such as polyethylene terephthalate (PET). More particularly, such a transfer chain is used to move the preforms after a loading item to and through a heating oven (tunnel oven) in which the material constituting the preforms is heated to be immediately molded, by a process of flexion or stretch-flexion, in a container of large size (definitive container or intermediate container). The transfer chain is further arranged so that the linear movement of the preforms is accompanied by a rotation of preforms on themselves so that the material is heated homogeneously all around the preforms, the heating means are arranged unilaterally in the oven. Figure 1 of the accompanying drawings represents, in diametrical section, in a relatively detailed manner, a preform support device arranged according to the usual technique while figure 2 shows, in top view, under the simplified form the coupling parts (fraction of the transfer chain) of a group of three devices according to figure 1. The preform support device, designated without its assembly by reference 1, has: a grooved plate 2 provided with coupling means with articulation with other two adjacent platens located respectively forward and backward (in the direction (arrow 3) of the chain offset); a hollow body fixed on the plate 2; here the body 4 is constituted in two parts, respectively upper and lower, fixed on the plate 2, for example respectively by screwing up and down the plate; and a rod 5 supported by said body in free rotation in the hollow body 4; shirts (shown, but without reference) inside the body 4 ensure the rod guide; in addition, the rod is apt to be displaced axially with recoil by means of a spring 6. At its free end (below on figure 1), the rod 5 is provided with a holding head 7 arranged to be removably or loosely coupled with the open end of a preform 8 (in the drawing, the apprehension head 7 is submerged by friction inside the opening of the preform 8). At its opposite end (above in figure 1), the shank 5 is integral with a sprocket 9 suitable for engaging with a chain with links (of the Galle chain type) that extends in a fixed manner along the path followed by the transfer chain, thanks to which the shank 5, and therefore the preform 8 that it supports, is put into rotation thereon when the transfer chain is in movement according to the arrow 3. The axial displacement of the rod 5 is obtained by means of a cam (not shown) carried on the sprocket 9. The multiplicity of the preform support devices coupled one after the other forms an endless transfer chain 10 (the fragment of which is schematized in FIG. 2) which must have an articulation capacity, especially , but not exclusively, in a horizontal plane (as outlined in figure 1). But furthermore, the proper development of the container manufacturing process requires that the preforms are placed in different attitudes at different points of the transfer: in particular they are loaded opening above the support devices 1, but they must be heated opening down in the oven , then they must be routed opening up to the exit of the oven to be transferred to the preform. The need arises for each support device 1 to have an ability to turn, independently of the devices that frame the front and back, around a horizontal axis, under the action of external guide cams. For these purposes, it is known that the coupling means of each support device 1 to the two adjacent devices front and rear comprise: at the rear end of the plate 2, a joint tail 11 supporting a coupling head 12 in a cap spherical for example convex with the convexity turned forward, which is intended to rest on the adjacent platen situated behind, at the front end of the platen 2, a seat 13 in the form of a spherical zone of complementary shape to the spherical cap, for example concave , and provided with a central axial opening 14 for the free passage of the joining tail 11 of the adjacent adjacent stage, whose convex spherical cap rests on said concave seat. This known arrangement has certain drawbacks inherent in the structure adopted. First, the spherical joint thus formed supports, alone, the tensile stresses during the movement of the transfer chain, as well as the friction generated during the rotation of the plates with respect to each other both in the chain curves of transfer as after the inversion of position of the preforms. The seats 13 are covered by a layer of self-lubricating material with a low coefficient of friction, such as TEFLON, but, taking into account the importance of the efforts exerted and the high speeds of mobility of the plates with respect to each other , this layer wears quickly and the seats 13 must be repaired. There is also a problem, since access to the seats for replacement and / or replacement requires the uncoupling of the coupled plates. As shown in Figure 2, each joint tail 11 has its end provided with a fillet and the coupling head 12 is blocked on the joint tail 11 by means of a nut 15. The access to the nuts 15 is narrow and little comfortable. In a general way, the preservation of the coupling means requires an interruption of the functioning of the installation that is long revealed taking into account the difficulties of disassembly and reassembly, and which is thus costly due to the loss of correlative manufacture. There is thus a pressing request from the users of the facilities that incorporate these chains of transfer of a structure that, while retaining the same operating capabilities, is less subject to wear and present a simpler structure that facilitates the disassembly and reassembly, in order to reduce the overall cost inherent in the conservation of the chain. In addition, the passage between the successive preforms, and therefore between the successive platens, is determined by the asse of the arrangement of the installation and is reduced to a minimum in the current installations: it is thus necessary not to accuse this asse and asse arrangement. do so that the improvements made to the platinas are inscribed in the restrictions of previously existing free spaces. For these purposes, a preform support device as defined in the prea is essentially characterized, as it is arranged according to the invention, in that: the spherical cap coupling head is supported in free rotation on the joint tail. a support plate is fixed, by means of the fixing means, to the free end of the joining glue, this support plate extends transversely to the joining glue and substantially parallel to the face of the coupling head opposite to that of the coupling head. its face in spherical cap, and - an annular bearing is interposed coaxially to the connecting tail between the faces mutually with respect to the coupling head and the support plate. Advantageously, the means for securing the support plate on the joining glue are arranged for an axial retention of said support plate on said joining glue and comprise: a hollow polygonal groove on the face of the opposite support plate to which the bearing has a radial groove hollowed out in the vicinity of the free end of the joining glue, and a retaining plate constituted by two parts glued edge to edge along a transverse asse edge, said plate retention which has a polygonal outer contour complementary to that of said groove and which has a central hole shaped to surround the union tail being joined in the throat thereof. Likewise, in order to obtain optimal operation of the device, the means for fixing the support plate on the joining tail are arranged to be fixed to said connection support plate and, for this purpose, the hollow throat in the joint tail has a polygonal outline and the contour of the central hole of the retaining plate is also polygonal and complementary to that of the throat. Preferably, the contour of the throat of the connecting glue is quadrangular rectangular, especially square. Thanks to the arrangement according to the invention, the two joints in rotation are physically separated: the ability of the plate to rotate about a horizontal axis is attributed to the bearing interface of the bearing plate and the coupling head, the fitness of the rotation of the plate in the curved parts of the transfer chain is conserved, alone, for the spherical head. The spherical head does not have to undergo the movements of rotation of great angular amplitude (180 °) inherent to the return of the preforms and does not suffer more than movements of relatively little angular amplitude: the layer of self-lubricating material that covers the seats then wears out considerably less fast. On the other hand, in a preferred embodiment, the retaining plate has a hollow axial groove on its face closest to the free end of the joining glue and shaped to receive the end of the joining glue extends beyond the throat. Advantageously, the hollow groove in said face of the retaining plate has a rectangular quadrangular contour, especially square. In this case, it is interesting that the face of the tip of the connecting tail, the previously mentioned face of the support plate and the previously mentioned face of the retaining plate are approximately coplanar: thus a nested structure is constituted which not only it does not entail lengthening the joining glue, but it can also make it possible to place a seat slightly less bulky than the seat used up to the present, and this fact has a remarkably increased contact surface which decreases the pressure exerted on the layer of material self-lubricating: hereby equally, the wear speed of the seat is significantly reduced. On the other hand, the simplified structure of assembly of the pieces on the joining glue does not resort to the screwing means, but only to the pieces fitted in one another: the disassembly and reassembly times in remarkable proportions are reduced. In total, the arrangement according to the invention makes it possible to separate the stoppages of operation of the transfer chain for preservation purposes and to shorten the duration of these stops. Thus, the profitability of the transfer chain is significantly improved without reducing its technical characteristics and mechanical reliability. The invention will be better understood upon reading the following detailed description of a preferred embodiment given solely by way of non-limiting example. In this description, we will refer to the attached drawings on which: Figure 3 is a schematic top view of a platen for a preform support device that is arranged according to the invention, Figure 4 is a sectional view according to the invention. the arrow IV-IV of figure 3, and figure 5 is a very schematic view illustrating a variant of arrangement of the stage. On figures 3 and 4, the same numerical references have been taken to designate the organs or parts identical to those of figures 1 and 2. As it is visible on figure 3, the coupling head 12 in spherical cap is supported in free rotation on the joint tail 11. A support plate 16 is fixed to the free end of the joint tail 11. The support plate 16 extends substantially transversely to the joint tail 11 and is substantially parallel to the face on the side of the bearing, substantially flat, of the coupling head 12. Between the faces mutually with respect to the coupling head 12 and of the support plate 16 an annular bearing 17 is interposed. This bearing 17 can advantageously be constituted under a very compact, according to the axial direction of the connecting tail 11, providing two annular grooves 18 and 19, located face to face and of the same diameter, hollow respectively on the faces with res With respect to the coupling head 12 and the support plate 16. A multiplicity of balls 20 are retained in said grooves being held approximately equidistant from one another, for example by means of spacers (not shown). The bearing plate 16 is retained axially on the connecting tail 11. To this end, the face, opposite to that of the bearings, of the bearing plate 16 is hollow with a central axial groove 21 of polygonal outline, preferably quadrangular rectangle, especially square. A throat 22 is radially recessed in the joining tail 11, in the vicinity of the free end thereof. This groove 22 can be discontinued, but preferably extends over the contour of the joining glue 11 as shown in FIG. 3. A retaining plate 23 is constituted by two half-pieces 23 a and 23 b glued edge-to-edge along a length of edge of transverse assembly. This holding plate 23 has a central hole 24 shaped to closely surround the bottom of the groove 22. The retaining plate 23 has an external polygonal outline in correspondence with the contour of the previously mentioned groove 21, so as to be able to fit it therein, this contour is preferably quadrangular rectangle, especially square, at cut angles as shown in figure 4. Furthermore, in combination with the dispositions that have just been exposed, provision is made for the support plate 16 to be joined in rotation to the tail 11. For this purpose, the groove 22 recessed in the connecting tail 11 extends over the entire contour of said glue and has a polygonal contour, preferably quadrangular rectangle, especially square, as clearly shown in FIG. 4., the central hole 24 of the holding plate 23 in two parts is of polygonal outline, preferably rectangular, especially square. Advantageously, as shown in FIG. 3, the face of the retaining plate 23, turned toward the free end of the joining glue, is also recessed with a central axial groove 25, shaped to receive the end of the glue. of junction 11 located beyond the throat 22. Thus, the support plate 16, the retaining plate 23 and the end of the connecting glue 11 are interconnected in an interesting manner, to reduce to the maximum the axial volume , it can be provided that the face of the tip of the connecting tail, the aforementioned face of the support plate and the aforementioned face of the retaining plate are approximately coplanar. The arrangement that we have just described allows us to keep the same input of plates as before, without modification of the rest of the installation, physically separating the function of articulation of the plates to adapt the curves of the transfer chain and the rotation function of great amplitude around a horizontal axis. Without increasing the volume of the coupling means of the plates to each other, it is possible to increase the diameter of the joining glue substantially (increase of the order of 50%), which on the other hand increases its mechanical resistance to traction . At the same time, it is also possible to increase the radius of curvature of the spherical head and of the seat, this increase which can be approximately three times the radius previously adopted. A considerable increase in the surface of the seat results, and thus, for a given tensile stress, a sensible reduction of the pressure exerted on the layer of self-lubricating material, with a considerably reduced wear thereof. In the assembly of the plates one of the following is carried out in the following manner. It is first started by assembling each spherical coupling head 12 with the corresponding support plate 16, with interposition of the bearing 17, the assembly is kept assembled provisionally by removable means (adhesive tape for example). One of these assemblies is disposed inside a platen 2 not equipped with the body 4 of the rod 5, then the joining tail 11 of an adjacent platen situated ahead is introduced through the assembly. The front stage is brought up to the stop so that the free end of the joining tail projects beyond the support plate. The two half-parts 23a and 23b of the plate 23 are now submerged in the groove 22. Then the adjacent platen positioned forward is deflected forward so that the retaining plate engages in the recess 21 of the support plate and that the face spherical convex, it rests against the concave seat 13, while the body 4 is mounted on the stage. The little play between the assembled body 4 and the face of the tip of the joint tail is sufficient to keep the two plates coupled to each other. Obviously and as a result of the foregoing, the invention is not limited to these embodiments and embodiments that have been considered more particularly; it covers, on the contrary, all the variants. In particular, it will be understood that the arrangement shown on the drawings with a coupling head 12 in a convex spherical cap of convexity turned towards the plate and a seat 13 with a concave complementary spherical area constitutes only one possible embodiment. The concavity and the convexity can be reversed, in position or in direction, without departing from the scope of the invention. Indeed, in the arrangement of figure 3, the direction of displacement of the chain can be done either in one direction (for example to the left, driving the spherical cap 12) as in the other direction (respectively to the right, driving the seat of the stage 2). Likewise, as shown in FIG. 5 in a very schematic manner, the coupling head 12 can be formed into a concave spherical cap with a concavity turned toward the platen, while the platen seat is convex, with the same conditions of dragging on a plate. sense or in the other than previously here.

Claims (13)

1. Preform support device (1) arranged to be associated with a multiplicity of analogous devices coupled with articulation one after the other in an endless chain of transfer of preforms with simultaneous rotation of these on themselves, this device has: a stage ( 2) provided with coupling means with articulation with two other adjacent platens located respectively forward and backward (in the direction (3) of the displacement of the chain); a body (4) fixed on the platen (2); and a rod (5) supported by said free rotation body with the possibility of axial displacement, this rod has an apprehension end (7) shaped to be movably secured to the open end of a preform (8); said coupling means have: • at a first end of the plate (2), a joining glue (11) that supports a coupling head (12) in spherical cap designed to rest on the adjacent stage located next to this first end, and at a second end, a seat (13) in the form of a spherical zone of complementary shape of the cap and provided with a central axial opening (14) for the free passage of the joining tail (11) of the adjacent stage located next to this second end, characterized in that: the coupling head in the spherical cap is supported in free rotation on the joining glue. a support plate (16) is joined, by means of a joint, with the free end of the joining glue (11), this support plate (16) extends transversely to the joining glue (11) and substantially parallel to the face of the coupling head (12) opposite its face in spherical cap, and an annular bearing (17) is interposed coaxially to the connecting tail between the faces mutually with respect to the coupling head (12) and to the plate of support (16).

The device according to claim 1, characterized in that the first end of the stage is its rear end with respect to the direction of travel of the chain and the second end is its front end.

The device according to claim 1, characterized in that the first end of the plate is its front end with respect to the direction of movement of the chain and the second end is its rear end.

4. The device according to any of claims 1 to 3, characterized in that the means for joining the support plate (16) on the joint tail (11) are arranged for an axial retention of said support plate on the union tail and comprises: an axial groove (21) of hollow polygonal contour on the face of the support plate (16) opposite to that of the bearing, a radial groove (22) recessed in the vicinity of the free end of the joining glue ( 11), and a retaining plate (23) consisting of two parts (23a, 23b) glued edge to edge along a transverse assembly edge, said retaining plate (23) has a polygonal outer contour complementary to that of said one. ribbed (21) and has a central hole (24) shaped to surround the union tail (11) being attached to the throat (22) thereof.

The device according to claim 4, characterized in that the means for securing the support plate (16) on the joint glue (11) are arranged to secure said support plate in rotation to said joint glue and in that with to this end, the groove (22) recessed in the joint tail has a polygonal contour and the contour of the central hole (24) of the retaining plate (23) is also polygonal and complementary to that of the throat (22).

6. The device according to claim 5, characterized in that the contour of the groove (22) of the connecting tail (11) is rectangular quadrangular.

The device according to claim 6, characterized in that the contour of the groove (22) of the connecting tail (11) is square.

8. The device according to any of claims 4 to 7, characterized in that the retaining plate (23) has an axial groove (25) recessed on its face closest to the free end of the joint tail and shaped to receive the end of the joint tail (11) extends beyond the throat (22).

The device according to claim 8, characterized in that the groove (25) recessed in the face of the retaining plate (23) has a rectangular quadrangular contour.

10. The device according to claim 9, characterized in that said grooving (25) has a square contour.

The device according to any of claims 5 to 10, characterized in that the face of the tip of the joining tail (11), the face of the support plate (16) opposite the bearing and face of the retainer plate (23) the one closest to the free end of the binding tail are approximately coplanar.

12. The device according to any of claims 1 to 11, characterized in that the annular bearing (17) interposed between the coupling head (12) and the support plate (16) comprises two face-to-face annular grooves (18, 19) respectively on the faces mutually with respect to the coupling head (12) and the support plate (16), and a multiplicity of bearing balls (20) housed in these grooves being held approximately equidistant from each other. The device according to any of claims 1 to 12, characterized in that the coupling head has the shape of a spherical cap with a convexity turned towards the plate and in which the seat has the shape of a concave spherical zone.