FR2735063A1 - Injection mould with pre-moulding, label cut=out stamping tooling - Google Patents

Abstract

A mould for making articles carrying at least one decorative label consists of one mould shell with a hollow impression and another, with a relief shaped to partially fill the impression, moving w.r.t. the first so that on closing to stamp out from a ribbon or sheet placed between the shells and the label. The first shell has a precutting tool (70,80) integral with it and placed upstream of it, w.r.t. the label ribbon, to form cutouts (41,46) in the label during mould closing. The tool is a plate (70) carrying drifts (71,76) and a plate (80) presenting guide holes (81,86) moving w.r.t. each other. At least one of the plates is made in a single piece with one of the mould shells.

Description

DEVICE FOR MANUFACTURING BY MOLDING A WORKPIECE
CARRYING AT LEAST ONE DECORATION LABEL
The present invention relates generally to the molding of plastic parts by injecting molten material into a mold, the cavity of which has the shape of the part to be obtained, said part carrying at least one decoration label.

 It relates more particularly to a device in which the decoration label is a portion of a ribbon, or of a plate, cut by stamping and positioned in the mold cavity by a mold element when the latter is closed. .

 A device of this type is for example described in American patent 3,427,688.

 The present invention seeks to propose a device which makes it possible to solve the problem which arises when the article to be molded must include an insert passing through the label or the decoration labels because it is then necessary to have labels having a opening for the passage of said insert.

 The device according to the invention also allows the production of articles comprising an insert of larger dimension than the opening made in the label.

 To this end, the invention provides a device for the manufacture by molding of an article carrying at least one decoration label, said device comprising a mold formed by a shell having a hollow imprint and at least one shell having a relief shaped so as to partially fill said hollow imprint, movable relative to each other away or in proximity, said relief cutting by stamping a ribbon or a label plate placed in the space separating the shells during its approach to the hollow imprint, characterized in that it comprises a precut tool integral with said mold and positioned upstream thereof in the direction of supply of the ribbon or the plate label for the formation of precuts in the ribbon or the label plate, said precut tool consisting of a plate carrying punches and a plate having openings of g uidage movable with respect to each other in approach and in distance in a direction parallel to the direction of movement of the mold shells, at least one of said plates being produced in one piece with one of the shells of the mold, in such a way that the formation of the precuts in the ribbon or the label plate situated upstream of the mold and the cutting of the label by stamping are carried out during the closing of the device.

The manufacturing device is still remarkable in that
- the label tape flows in a groove in one of the plates of the precut tool,
the front wall of the relief has a boss surrounding the outlet of the injection nozzle, and in that the precut tool makes a precut in each label for its positioning around said boss of the injection nozzle,
- for the molding of a part comprising an insert protruding from the face carrying the label, lton provides for the production of a precut by the precut tool,
one of the mold shells has a housing in which the insert is put in place from the molding cavity by crossing the precut of the label tape,
- it allows the manufacture of an article having two labels arranged on its large faces and an insert passing through one of its decorated faces,
it allows the manufacture of a part having two labels arranged on its large faces and an insert protruding on either side through said labels,
the insert is of larger dimensions in its part lying between the labels than in its parts passing through said labels,
the mold comprises two shells having a relief, with a view to cutting by stamping two ribbons or label plates, said ribbons or label plates are moved in crossed directions relative to one another,
- it allows the manufacture of a part having at least one label and an insert not extending outwardly,
it comprises a pusher disposed in the shell and urged in the direction of the molding cavity by an elastic means for placing the label against the relief,
- it allows the molding of an object of great length but of fairly small width, pre-cuts of the label tape at the end locations of the label which must be cut by the relief of the shell being made by punches of the precut tool in order to overcome the problem of lengthening the label during molding,
- the pre-cutting tool provides at least one pre-cutting for positioning the tape or the label plate.

The invention will be better understood thanks to the description which follows given by way of nonlimiting example with reference to the appended drawings in which
FIGS. 1a to 1c represent three successive stages in the implementation of a first embodiment of a device according to the invention,
- figure id shows the product produced by the device shown in figures la to lc,
FIGS. 2a to 2c represent three successive stages in the implementation of a second embodiment of a device according to the invention,
FIG. 2d shows the product produced by the device shown in FIGS. 2a to 2c,
FIG. 3a shows a device according to a third embodiment of the invention in the closed position,
FIG. 3b shows the product produced in the device of FIG. 3a,
FIG. 4a shows a device according to a fourth embodiment of the invention in the closed position,
FIG. 4b shows the product produced in the device of FIG. 4a,
FIG. 5 shows a device according to a fifth embodiment of the invention in the closed position,
FIGS. 6a and 6b respectively represent a device according to a sixth embodiment of the invention, and the precuts made in the label tape,
FIGS. 7a and 7b are figures similar to those of FIGS. 6a and 6b for an installation allowing the molding of two articles during the same operation,
- Figures 8 and 9 show two embodiments of a device according to the invention in which are visible means for positioning the label.

 As can be seen in FIG. 1 a and in a manner known per se, a mold allowing the cutting by stamping of a ribbon or of a label plate generally consists of a shell 1 having a hollow imprint 10, and a shell 2 having a relief 20 movable with respect to each other in distance or approximation in the direction noted ZZ in the drawing.

 The hollow imprint of the shell 1 has a flat bottom 13 and a cylindrical peripheral wall 12 which is perpendicular to it and is parallel to the direction Z-Z of displacement of the shells. This wall can take any cylindrical shape generated by a straight line perpendicular to the bottom 13 moving along any closed line.

 The relief 20 of the shell 2 has a peripheral wall 22 similar to the wall 12 of the cavity 10 and dimensioned in such a way that said relief can penetrate into the hollow cavity 10.

 The front face of the relief 20 shown in the drawing is flat, this front face could be of any other shape in other examples of implementation of the invention, provided that the peripheral wall 22 remains capable of cutting the label by stamping.

 Said relief and imprint are such that when the two shells of the mold are brought together until their peripheries 14, 24 bear one on the other, as shown in FIG. Ic, the relief 20 penetrates into the hollow imprint 1 and partially fills it defining a molding cavity 3 whose shape corresponds to that of the part to be manufactured. The peripheral walls 12 and 22 are shown remote from each other for the clarity of the drawing but it is understood that they are dimensioned so as to fit together ensuring perfect cutting of the label and preventing any material leak.

 A ribbon 4 of labels is supplied and placed in the space left free between the shells 1 and 2 of the open device before they are brought together, between the hollow imprint 10 and the relief 20.

 This ribbon is arranged in a plane perpendicular to the direction Z-Z of closure of the mold. It is supplied in the direction X noted in FIG.

 When the mold is closed, as shown in FIG. 1c, the relief 20 presented by the shell 2 cuts by stamping the label ribbon and separates a label 40 therefrom.

 This label 40 is exactly of the desired dimension since it is cut out by the relief 20 dimensioned so as to be inserted exactly by its peripheral wall 22 in the hollow imprint 10.

 The front wall of the relief 20 has a boss 21 surrounding the outlet of the injection nozzle 23.

 This boss allows the positioning of the label 40 against the flat front wall of the relief 20.

 The label 40 is, if necessary, held in place against the front wall of the relief by known means not shown in the drawing such as suction nozzles opening into said front wall or by the cooperation of pins of the front wall with openings of said label.

 The material injected into the cavity 3 by the injection nozzle 23 fills said cavity and places the label 40 against the relief 20.

 In a manner known per se, the mold can be partially closed at first, taking care to allow the label to be cut, in order to leave a larger cavity than that necessary for the part to be manufactured. A predetermined quantity of material is injected into this larger cavity, then the complete closing of the mold ensures the pressurization of the material. Such an injection technique facilitates the injection of the material which takes place in a larger cavity and reduces the stresses suffered by the label.

 The use of a device ensuring the stamping of a label ribbon when it is closed makes it possible to obtain a good quality molded part carrying a decoration label without the need for prior cutting and handling means. of the label, the label being automatically cut securely to the correct size.

 The use of ribbons or label plates makes it possible to provide decorated products at reduced cost.

 Label tapes or cutting plates are indeed very quick to produce and very inexpensive in comparison with the image transfer films usually used for decorating molded products. A re-printed label tape may be available in less than a week while image transfer films take approximately six weeks to complete.

 The use of a label tape in the device shown in FIGS. 1a to 1c requires providing a precut 41 in each label for its positioning around the boss 21 of the injection nozzle.

 The mold of FIGS. 1a to 1c being further produced in order to allow the molding of a part comprising an insert 6, it is also necessary to provide a second pre-cut 46 in the label tape.

 These precuts can be made during the manufacture of the ribbon or of the label plate, but it is then difficult to ensure perfect positioning of these cuts in the molding cavity.

 According to the invention, the precuts 41 and 46 are produced in the label tape during its use in the manufacturing device according to the invention.

 To this end, a precut tool consisting of a plate 70 carrying two punches 71 and 76 and a plate 80 having two guide openings 81 and 86 is provided on the path of the label tape in the direction of the cavity of molding and positioned immediately upstream thereof when considering the direction of supply of said ribbon.

 According to the invention, this precut tool is integral with the mold, at least one of its plates being linked to one of the mold shells.

 In the example shown in Figure la, the two plates of the precut tool are integral with the mold shells. The plate 70 is linked to the shell 2 of the mold and the plate 80 is linked to the shell 1 of the mold, the plate 70 and the shell 2 being produced in one piece, the plate 80 and the shell 1 of the mold also being produced in one piece.

 By this embodiment according to the invention, a perfect simultaneity of the movements of the precut tool and of the mold is ensured and therefore a simultaneity of the cuts made by the punches 71 and 76 and by the relief 20 in the label tape. . This simultaneity allows good cuts to be made in the label tape without risking distortions due to the fact that the tape subjected to successive cuts could be deformed.

 In the exemplary embodiment shown in FIGS. 1 to 1, the device allows the production of an article 31 having a label 40 and an insert 6 projecting from the face carrying said label.

 Before closing the mold, the insert is positioned, starting from the molding cavity, through the pre-cut 46 of the label tape to be put in place in the housing 26 of the shell 2. A suction can be provided in a passage 25 for its retention in said housing 26.

 This positioning will preferably be carried out by a manipulator arm which will simultaneously push the label tape in the direction of the shell 2 so as to position the precut 41 around the boss 21 surrounding the injection nozzle 23.

 During the closing of the mold, the precut tool practices the precuts 41 and 46 of the label which has not yet entered the mold and the separation of the label 40 intended to cover the product to be molded.

 When the device according to the invention is in the closed position of FIG. Ic, the material is injected through the nozzle 23 to fill the cavity 3.

 When the device is opened, there is an article 31 bearing the label 40 and the insert 6.

 The label ribbon 4 is then advanced so as to position the precut 41 and the precut 46 made by the tool in the label located upstream of the mold in front of the boss 21 and the housing 26 of the shell 2 for molding of a new article.

 In the embodiment of Figures 2a to 2d, the article 32 to be produced has two labels 40 and 50 arranged on its large faces and an insert 6 passing through one of its decorated faces.

 In this exemplary embodiment, the mold comprises two shells 2 and 9 arranged on either side of a central shell formed by an extension of the plate 82 of the precut tool, said shells moving relative to each other following direction ZZ when closing the mold.

 The label tape 4 flows in the direction X in the same way as in the previous embodiment.

 FIGS. 2a to 2c show an alternative embodiment of a plate 82, presenting the guide openings, of the precut tool in which the label tape is held in position relative to the relief 20 by circulating in a groove 84 of said plate 82.

 The label 50 is like the label 40 cut by stamping in a label ribbon 5 when the mold is closed.

 To this end, the shell 9 of the mold is shaped with a relief 90 similar to the relief 20 of the shell 2 so as to cut by stamping the label tape 5 during the penetration of said relief 90 into the cavity 83 of the central shell .

 In order to facilitate the arrangement of the device, provision is made for crossed directions of movement of the label ribbons 4 and 5.

In the embodiment shown in Figure 2a, the label tape 5 is then arranged perpendicular to the tape 4 and flows in the direction
Y.

 Any other crossed direction may of course be suitable, for example at an angle of 30 or 609.

 The operation of this device is similar to that of the device shown in Figures la to lc.

 When the mold is closed, the reliefs 20 and 90 of the shells 2 and 9 penetrate into the cavity 83 of the central shell by cutting by stamping labels 40 and 50 from the ribbons 4 and 5. At the same time, precuts 41 and 46 are formed in the ribbon 4 upstream of the mold by the precut tool 70, 82.

 The shells 2 and 9 approach each other until their faces 24 and 98 are respectively in abutment against the faces 14 and 89 of the central shell.

 During the material injection, the label 50 is pressed against the bottom of the molding cavity by the material flow.

 In the alternative embodiment of FIG. 3a, the device is intended for the manufacture by molding of a part 33 carrying two labels 40 and 50 and enclosing an insert 61 protruding on either side of the part 33 through said labels .

 The molding device used in this embodiment is similar to that of FIGS. 2a to 2c and comprises on the path of the label tape 5 a precut tool, not shown in the drawing, similar to the tool formed by the plates 82 and 70.

 This precut tool comprises at least one plate secured to the shell 9.

 This precut tool makes it possible to perform a precut 56 for the insertion of the insert in the part of the ribbon 5 disposed upstream of the molding device which is intended to form the label 50 of the article 33 which will be molded during of the next closing of the mold.

 In the example shown in the drawing, the insert is of larger dimensions in its part between the labels than in its parts passing through said labels.

 The production of such an article comprising an insert which cannot completely pass through the opening of the label is possible with the molding devices according to the invention because the insert is placed from inside the mold.

 When, conversely, the outer part of the insert is larger than the opening in the label, the insert will be placed before the label.

In this case, the insert can be brought through a passage made in the mold shell.

 In the alternative embodiment of FIG. 4a, the molding device is intended for molding an article comprising an insert 62 which does not extend outwards.

 In this embodiment, the precut tool 70, 85 only performs the precut 41 necessary for the positioning of the label around the boss 21 surrounding the injection nozzle 23.

 The shell 2 has pins 27 protruding from the front face of the relief 20 and intended to penetrate into openings that the insert has for this purpose.

 In FIGS. 4a and 4b, the insert 62 has been shown embedded in the thickness of the article 34 between the labels 40 and 50. A similar article with the insert arranged so as to have a face flush with the surface through the one of the labels will be easily manufactured provided that the opening of the label is provided through which said insert must be positioned so as to be placed against the relief of the shell 2.

 Figure 5 shows an alternative embodiment of the molding device according to the invention in the case where it is not possible to position the opening 41 of the label 40 around the boss 21 by a manipulator arm. This can for example occur if an insert is not placed in the article and therefore there is no provision for a manipulator arm, or when the insert is positioned in the mold at a too great distance from the boss 21 in order to have the label bear around the boss 21 by the manipulator arm ensuring the insertion of the insert.

 In this embodiment, a pusher 91 urged in the direction of the molding cavity 83 by an elastic means such that the spring 92 shown in the drawing is placed in the shell 9.

 When the closing of the mold is finished and the labels 40 and 50 are cut from the ribbons 4 and 5, said pusher 91 maintains said two labels against the relief 20 of the shell 2 as shown in FIG. 5.

 During the injection, the material gradually repels the label 50 and the pusher 91 until said label 50 bears against the front face of the relief of the shell 9.

 In the example shown in Figures 6a and 6b, the object to be molded is very long but of fairly small width. Tests have shown that the elongation in the width direction is small enough that the label is not caused to protrude unacceptably in the transverse direction. On the other hand, the elongation in the length direction is important and not acceptable for the quality of the finished object.

 Pre-cuts 141 of the label ribbon are then provided at the end locations of the label which must be cut by the relief 20 of the shell 2.

 These precuts 141 are made by the punches 171 of the precut tool linked to the mold.

 In the embodiment shown in FIG. 6a, the plate 170 of the cutting tool is integral and produced in one piece with the shell 2 of the mold while the plate 180 is not integral with the shell 1. These two plates are however driven in approach and in distance in a direction parallel to the direction of opening and closing of the mold shells.

 In such an embodiment, the production of the precuts in the label tape will of course be carried out during the closing of the mold, but may be done while the mold remains closed, during the injection of material, and not during the movement of reconciliation of the shells. To this end, it is possible to use a means such as a pneumatic cylinder for bringing the plates of the cutting tool closer and further away.

 During the stamping of the ribbon by the relief 20 during the closing of the device, the cutting of the ribbon is made along the outermost line 142 shown in FIG. 6b, but the label 143 thus cut is of surface reduced to the hatched part on this same figure.

 It is of course necessary to be particularly vigilant when defining the opening 141 so that, during molding, said label 143 of reduced surface lengthens just enough to exactly cover the face of the molded article.

 In this exemplary embodiment, the label is intended for the decoration of the face of the article in abutment against the bottom of the cavity 13. The label falls into the bottom of said cavity during its cutting and is pressed against this melts by the flow of material injected into the cavity. In this exemplary embodiment, there is no provision for a boss around the outlet of the injection nozzle because the article to be molded does not bear a label on the face bearing against the relief 20.

 The exemplary implementation of the invention shown in FIGS. 7a and 7b relates to the molding of two pieces with prior cutting of the label tape so as to on the one hand overcome the problem of the elongation of the label , and on the other hand provide for selected areas of the object not presenting a label.

 In the device shown in FIG. 7a, it is the plate 185 having the guide openings which is integral with a shell of the mold while the plate 175 carrying the punches is free.

 FIG. 7b represents the label ribbon after it has passed through the precut tool. It includes precuts 144 of square section in the example shown and precuts 141.

 In this exemplary embodiment, two objects are molded in the device, respectively in parts A and B of the imprint. These objects are thin cards such as bank, telephone, subscription cards ...

 These objects are, during demolding, connected by a bridge of material placed above the thinned connection 145 presented by the label 143 and bearing the trace of the injection nozzle 23.

 This clip is cut along lines C-C and D-D to separate the cards.

 Similarly, although this has not been shown in the drawing, other precuts can be provided in order to compensate for an elongation of the label in the direction of its width for objects of large dimensions.

 FIGS. 8 and 9 show two exemplary embodiments of a device ensuring the positioning of the label tape 4 relative to the molding cavity 13.

 In the embodiment shown in FIG. 8, the precut tool linked to the practical mold, in addition to the precuts 41 and 46 intended for the passage of the boss 21 and the insert 6, the precuts 49 for positioning.

 These pre-cuts are made by additional punches 79 of the plate 72 fitting into openings 89 of the plate 88.

 During the advancement of the ribbon 4 in the direction denoted X in the drawing, the latter is moved until the positioning pre-cuts 49 are arranged opposite openings 29 of the shell 2 intended to engage on pins 19 carried by the shell 1.

 In the embodiment shown in FIG. 9, the precut tool only performs a positioning precut 49 in the ribbon 4.

 This pre-cut 49 is then placed in front of openings 29, 15 formed in correspondence in the mold shells. Monitoring of the correct positioning of the strip 4 with the precut 49 in front of the openings 29, 15 is ensured in the example shown by an optical device comprising a light emission means L and a cell C receiving said light.

 As a variant, a multiplicity of cutouts 49 is provided on at least one of the longitudinal edges of the ribbon 4, said cutouts being spaced apart in a regular manner in the manner of the openings present along the papers intended for printers connected to computer devices.

 The cutouts 49 are then used both to precisely guide the ribbon in its movement inside the mold by making said cutouts cooperate with drive wheels having spikes and to control the length of travel of said ribbon.

 To limit the possible wear of the edge of the relief 20 by which the label is cut and to position said relief in a perfect manner at the time of stamping, provision is made to guide the shells by known means consisting of a column moving in a bore provided with guide balls, the shells being after molding separated by springs. These known guide means are not shown in the drawings.

Other alternative embodiments of the device of the invention can of course be provided without departing from the invention. It is for example possible to design the shell 2 having the relief 20 in two or more shells separating in different directions from Z
Z in order to allow the molding of a part portion in the internal space of the relief, said portion being integral with that molded in the cavity 13 and bearing the label.

We would thus obtain pieces having a decorated base. By way of example, it is conceivable to mold pieces for chess games bearing a marking at their base, or even directly the velvety coating usually attached by gluing.

Claims (13)

 1. - Device for the manufacture by molding of an article carrying at least one decoration label, said device comprising a mold formed by a shell having a hollow imprint and at least one shell having a relief shaped so as to partially fill said hollow imprint, movable relative to one another away or in proximity, said relief cutting by stamping a ribbon or a label plate placed in the space separating the shells during its approximation of the hollow imprint, characterized in that it comprises a precut tool (70, 80 ;; 70, 82) integral with said mold and positioned upstream of the latter in the direction of supplying the ribbon or the label plate for the formation of precuts (41, 46, 49, 141) in the ribbon (4) or the label plate, said precut tool consisting of a plate (70, 72, 170, 175 ) bearing punches (71, 76, 171, 79) and a plate (80, 82, 88, 180, 185) having guide openings (81, 86, 89) movable with respect to each other in approach and in distance in a direction parallel to the direction of displacement of the mold shells, at least one of said trays being made in one piece with one of the mold shells, so that the formation of pre-cuts in the ribbon or the label plate located upstream of the mold and the cutting of the label by stamping is carried out during the closing of the device.  2. - Device according to claim 1, characterized in that the label tape flows in a groove (84) of one of the plates of the cutting tool.  3. - Device according to any one of claims 1 or 2, characterized in that the front wall of the relief t20) has a boss (21) surrounding the outlet of the injection nozzle (23), and in that l 'precut tool practices a precut (41) in each label for its positioning around said boss (21) of the injection nozzle.  4. - Device according to any one of the preceding claims, characterized in that for the molding of a part comprising an insert (6) projecting from the face carrying the label, provision is made for a precut (46) by the precut tool.  5. - Device according to claim 4, characterized in that one of the shells (2) of the mold has a housing (26) in which the insert is put in place from the molding cavity by crossing the precut ( 46) label tape.  6. - Device according to any one of the preceding claims, characterized in that it allows the manufacture of an article (32) having two labels (40, 50) arranged on its large faces and an insert (6) passing through a of its decorated faces.  7. - Device according to any one of claims 1 to 5, characterized in that it allows the manufacture of a part (33) having two labels (40, 50) arranged on its large faces and an insert (61) protruding from both sides through said labels.  8. - Device according to claim 7, characterized in that the insert (61) is of larger dimensions in its part between the labels than in its parts passing through said labels.  9. - Device according to any one of claims 6 to 8, characterized in that the mold comprises two shells (2, 9) having a relief, with a view to cutting by stamping two ribbons (4, 5) or plates label, said ribbons or label plates are moved in crossed directions relative to each other.  10. - Device according to any one of claims 1 to 5, characterized in that it allows the manufacture of a part (34) having at least one label (40, 50) and an insert (62) is not not extending outward.  11. - Device according to any one of the preceding claims, characterized in that it comprises a pusher (91) disposed in the shell (9) and urged towards the molding cavity (83) by elastic means (92 ) for placing the label (40) against the relief (20).  12. - Device according to any one of claims 1 to 5, characterized in that it allows the molding of an object of great length but fairly small width, pre-cuts (141) of the label tape at the locations d end of the label which must be cut by the relief (20) of the shell (2) being effected by punches (171) of the precut tool in order to alleviate the problem of the elongation of the label at the during molding.  13. - Device according to any one of the preceding claims, characterized in that the precut tool linked to the practical mold at least one precut (49) for positioning the ribbon or the label plate.