DE2258451A1 - METHOD AND DEVICE FOR SHAPING OBJECTS, IN PARTICULAR SOLES MADE OF RUBBER, WHICH HAVE TWO DIFFERENT COLORED RUBBER LAYERS OR AREAS - Google Patents

Description

1633

, ". PATENT LAWYERS

DR.-ING. R. DÖRING DIPL.-PHYS. DR. J. FRICKE

BRAUNSCHWEIG MUNICH

UNIROYAL, Inc. _ 1230 Avenue of the Americas, New York, NY 10020 / USA

Method and device for molding objects, in particular soles made of rubber, which are two different have colored rubber layers or areas "

-The invention relates to a method and a device for Shaping of objects from rubber, in particular soles for footwear, which layers two differently colored rubber layers. or areas. '

There are devices known which ensure that at Use of two different colored rubber materials to form soles for or on footwear a sharp boundary line is retained between the two rubber materials. ' The problem of obtaining such a sharp borderline arises by the fact that the two types of rubber. the tendency have to mix in the "'hollow mold during the injection process of the second or outsole rubber.

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To cope with this problem, a shape is suggested been, which means for fastening a listed shaft to limit the mold space in one direction and has a Pormring, which corresponds to the circumferential course of the sole and accommodates a movable sole plate, which serves to spread and compress the rubber material introduced into the hollow mold. According to the known Execution, the molded ring is equipped with a few inlet openings for the different colored rubber materials. The openings are provided at a distance from one another in the direction of movement of the sole mold plate in the mold ring. if the first rubber material is introduced and the movable sole plate is moved against the shaft and thus the first rubber material is pressed against the bottom of the upper to close the first layer of the sole (i.e. midsole) of the footwear shape, form and move continuously around the edge of the movable sole plate and along the inner wall the ring's thin squashed edges. These squashed edges are in a circumferential groove of the sole mold plate caught and form a bead there, which is connected to the midsole by an easily tearable and weakened Section is connected. After the midsole has been shaped and at least partially cured or has been fully vulcanized, the sole mold plate is moved away from the midsole to make room for the second outsole rubber compound to release. When performing this movement,

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the bead formed in the groove by the entry of the "rubber" from the partially cured or vulcanized first Rubber separated by tearing the zone of weakness of the pinch, leaving a sharp dividing line between the The midsole and the outsole that is now to be shaped is created. When the second rubber layer is subsequently formed, the Rubber bead a good seal against the emergence and pre-growth from edge crushing of the second rubber layer.

It has been found, however, that when the zone of weakness is torn from time to time parts of this zone of weakness are broken into fragments or small pieces are torn which do not remain attached either to the bottom of the midsole or to the rubber bead formed in the sole mold plate. These particles ^ so became found, mix with the second rubber material when this is introduced or injected, so that the color of the second rubber material is impaired.

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The object of the invention is to provide a method and a device of the type mentioned in the introduction in such a way that the described disadvantages, namely the occurrence of the impurities or the color impairment of the two differently colored Rubber materials avoided in the manufacture of two-tone rubber objects, especially soles for footwear will. .

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To solve the above problem, the invention provides a method using a hollow mold with closed Sidewalls, a device determining the mold surface and a movable mold member enclosed by the side walls for forming the lower surface of the mold, which Mold member has a circumferential wall area for tight sliding guidance in the side walls of the mold and in the direction of pointing the way to the lower surface of the forn, an adjoining one Has a circumferential groove, wherein the rubber layers in different positions of the movable mold member one after the other are introduced into the mold and is characterized by the fact that the hollow shape is used to remove loose particles of the is blown through the first rubber layer or ply before the introduction of the second rubber layer.

According to the invention it is provided that the first rubber layer into the hollow mold through a first injection opening and the second Rubber layer through a second, spaced apart from the firstep Injection port while the gas is injected through one of the injection ports for the Rubber material away from the third opening and the drain of the gas through a fourth opening, approximately in the same plane as the third opening, but far away from it opening is made. The movable molded member is at least as far as the plane of the third or fourth opening

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movable and the blowing is in this position of the movable Form member carried out. After blowing through the Mold and before injecting the second rubber layer, the movable mold member is in a plane between the second and the third or fourth opening moves.

When shaping or molding a two-tone rubber sole a listed shaft is first proceeded in the manner described above, the shaft being the upper one Completion of a configuration corresponding to the sole Form forms, and it is initially through a first opening the first rubber layer for covering the shaft or for forming the midsole is injected in a predetermined amount and then distributed over the bottom of the shaft and pressed against this bottom by the movable sole plate and the Mold plate held in this position until sufficient Solidification or vulcanization takes place around the molded sole plate in a practically pure state to lift off from the middle sole and withdraw. Form during the pressing process

'the already mentioned lateral squeezes of the first rubber material, which in the circumferential groove reach the movable sole plate and form a bead there, which with the midsole by a slightly tear-open or tear-off weakening zone is connected.

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When the sole plate is moved away from the midsole and the midsole is sufficiently vulcanized, the circumferential bead in the groove of the sole plate is through Separation of the weakened zone from the midsole and later forms a good seal against the development further lateral squeezing of the second rubber material which is injected. When separating the bead ^ from the Midsole a sharp dividing line is formed between the midsole and the outsole to be shaped later,. however, despite this very clean separation, they remain in the space between the movable sole plate and the midsole small rubber particles of the first rubber layer, separated from the midsole and also from the bulge in the groove. In order to remove these loose particles, the sole mold plate Moved downward so far that it exposes the gas inlet and gas outlet openings and compressed air into the hollow mold can be blown in, which conveys the loose particles of the first rubber layer out of the cavity. Then the rubber of the second or outsole enters the cavity introduced and the sole plate again moved against the shaft, so that a distribution and pressing of the second Rubber material takes place against the first rubber material and is held in the pressing position until a secure connection this second rubber layer achieved with the midsole and the movable sole plate without adhesions from the outsole can be separated.

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As a modification of this prescribed method of operation, the sole plate can first of all before the introduction of the second rubber compound moved towards the midsole beyond the gas inlet and outlet openings (but not beyond the inlet openings for the second rubber layer), so that the compressed air, inlet and outlet openings to prevent ingress of the rubber of the second rubber layer.

Further details of the method and also of the device emerge from the following description of an exemplary embodiment as well as the subclaims:

Pig. 1 is a schematic representation of an apparatus for manufacturing a two-tone rubber sole by Formation on a listed shaft, the shaft being shown with a downward facing covering midsole;

Fig. 2 shows a detail partly in section, partly in elevation and in an enlarged view in comparison 1, the heel part of the arrangement according to FIG. 1 being shown in detail in a position of the movably held sole mold plate after injection of the first rubber material and during the pressing of the midsole thus formed against the shaft;

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Pig. 3 shows the arrangement similar to Pie * 2, however with the sole plate in a fully retracted, distant position from the shaft after their separation from the midsole in one position in which the flask shape is cleaned;

Pig. · H shows, similar to FIGS. 2 and 3, part of the arrangement according to FIG. 1 with a position of the sole mold plate after the hollow mold has been cleaned;

Fig. 5 shows a partial section of the arrangement in one position of the sole plate immediately after it has taken place Introducing the * second rubber material for the outsole, with details in an enlarged view the edge formation of the sole plate can be seen;

Figure 6 is a top plan view of the mold ring of the device.

The device, designated as a whole by 10, for shaping or molding a two-tone sole onto a listed one The shaft has a shaped ring 12, which can be seen particularly clearly from FIG. The shaped ring 6 has an outer rectangular shape and inside a 'recess or wall 14 in the mold the sole to be molded. Slidably fitted into aen shaped ring 12 and thus at a very short distance from the V.'an

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dung l4 runs the circumferential wall of a sole plate l6, which is vertically movable and can be driven by a piston-cylinder arrangement 18 known for this purpose. Through appropriate Actuation of the piston and cylinder device 18, the sole Pormplatte 16 from a fully retracted Position as in Pig. 1 is shown in solid lines, in a pressing position according to FIG. 2 transferred in which they only have a small gap between the bottom of the mounted in a known manner on the mold ring Listed shaft 20 leaves. .

The Pormring 12 has four passages or through openings Mistake. The first passage or opening 22 extends horizontally through the ring into the interior of the mold, which is hereinafter referred to as the mold cavity 24. The mold cavity is determined by the inner mold wall 14 of the mold ring, the upper surface 26 of the sole mold plate 16 and through the lower surface of the footwear to be manufactured or completed, i.e. either from the bottom of the listed upper 20 'or the bottom of a midsole "28, which is produced during the process according to this invention. "" '

The Pormring 12 is equipped with a second passage or passage opening 30 for the introduction of the second or Outsole rubbers, with a third pass or one

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third inlet opening 32, which, as shown, in a Angle to the through openings 22 and 30, although they also ir.it these could run in one direction, and the connected to a compressed air source (not shown), preferably via a suitable valve for controlling the compressed air is, the control valve is also not shown. Finally, there is a fourth opening, namely a passage opening 3 ^ provided in the Pormring 12, which is preferably lies in the same plane, but in the hollow mold opposite the inlet opening 32> to ensure that when compressed air is introduced through the inlet port 32 into the Hollow form sweeps this compressed air into the interior of the hollow form 24 and emerges again from the outlet opening 3 ^.

The shaped sole plate 16 is provided with a circumferential recess or groove 36 which is arranged in the circumferential side wall 33 of the sole plate. The recess or groove 36, which preferably, but not necessarily, has a semicircular cross-section, opens outwards in the direction of the inner wall surface lU of the mold ring. The peripheral surface 38 of the sole mold plate 16 and the inner wall surface 1 * 1 of the mold ring 12 form a slide Seat. Accordingly, the rail mold plate can be moved freely in the mold ring 12 in the direction of the listed shaft 20 and away from it. The gap between the circumferential surface 38 of the mold plate 16 and the wall surface 14 of the mold ring 12 is shown exaggerated in Figures 2 to 5 inclusive

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to facilitate understanding of the present invention. The ' Surface 2o of the sole mold plate 16 has a circumferential edge zone 42, which is an inwardly inclined boundary wall shows, which is inclined about 18 to 70 ° with respect to the vertical is. the circumferential wall surface 38 of the sole Pormplatte 16 includes a peripheral wall portion 44, which between the groove or groove 36 and the inclined surface 42 is provided and preferably extends completely around the sole Pormplatte around and in the closest vicinity the inner wall surface 14 of the mold ring 12 extends.

When using the device, the sole plate 16 is first held at the level of the inlet opening 22 and preferably above the inlet opening 32 and the first or midsole rubber is introduced or injected into the hollow mold 24 through the inlet opening 2'2 with the aid of this. Procedure of known institutions. Then the sole-Pormplatte 16 is moved in the direction of the listed shaft 20. During this movement of the sole against the Pormplatte been rendered shaft 20, the rubber material introduced against been rendered shaft 20 is pressed and thus forms the midsole 28. In this case, check Randabquetschungen form of the gum., D h _o. the .'Gummi squeezes between the peripheral wall 28 of the sole form plate into the narrow gap between the slidingly guided sole form plate and the inner ring wall 14 and also passes through the peripheral wall area 44 _a from which it then enters

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the semicircular groove or groove 36 gets there to form a bead as this is the purpose of the groove 36.

The sole plate 16 is shown in FIG Position held until the first rubber layer forming the midsole 28, the bead 48 in the groove 36 and the weak connecting part 50 between the midsole 28 and the bead 48 sufficiently vulcanized and so the midsole is vulcanized onto the listed shaft 20 and a clean separation of the surface 26 of the sole mold plate l6 from the lower surface of the now molded midsole.

This downward or retreating movement of the sole forming plate causes the rubber bead 48 to move away from the midsole 28 the zone of weakness 50 is separated so that the bead 48 which has formed in the recess or groove 3,6, remains in this and is moved downwards with. This separation along the weakening zone 50 and the frictional movement of the Rubber bulge 48 on the inner wall 14 leads to the formation of some loose particles of the rubber material introduced first, which are now in the mold cavity 24.

To get this loose, from that. first rubber material

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goblets from the mold cavity before the introduction of the second rubber material to eliminate in the Pormhohlraum and thus a connection To prevent these particles with the second rubber material, the sole-forming plate 16 with the piston-cylinder-kin direction 18 is moved downwards until it reaches the position shown in Fig. ' 1 position shown in solid lines (see also Fig. 3) below the level of the inlet and outlet openings 32 and 3 ^ of the compressed air has reached. The remains in this position Sole molding plate 16 and with the aid of valves or other devices of known type is compressed air through the inlet openings 32 let into the mold cavity, which through the Sweeps through the mold cavity and exits through the outlet opening 3 ^. The compressed air moves through the cavity of the mold with sufficient speed to remove the loose particles to capture the first rubber layer and discharge it through the outlet opening 3 ^. The working conditions during air purification of the mold cavity are best seen in Fig. 3.

While using any suitable air velocity it has been found that a satisfactory cleaning effect is achieved when the air is at a pressure of approx. 6 kg / cm fed through the inlet opening of about -3 mm in diameter The outlet opening 34 expediently has the same diameter. However, it is advantageous if, given the dimensions of the inlet and outlet openings, a pressure of approx.

ρ
10 kg / cm is applied.

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After the cleaning process has been carried out and in accordance with the present invention, the sole mold plate remains 16 in the in, .Fig. 3 position shown, while the second or outsole rubber compound is introduced into the mold cavity 24 through the second entrance opening 30. The piston and cylinder device 18 is then actuated to move the sole plate 16 out of its fully retracted position as shown in FIG in the position shown in Fig. 5 to transfer the second amount or layer of rubber 52 over the outer surface of the · To distribute the midsole 28 and to keep the rubber layer 52 pressed against the midsole 28 until sufficient Vulcanization has occurred, which results in a clean separation between the surface 26 of the sole mold plate 16 and the lower surface the newly formed outsole 5.2 is possible. During this vulcanization and pressing of the outsole. 52 only exists there is very little risk of edge squeezing or squeezing of the second rubber compound, since the rubber bead 48 of the first Rubbers act as a seal to prevent a

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noticeable edge squeezing can arise during the second pressing process. If now the sole form plate l6 for the second Once withdrawn, a double-soled article of footwear has been molded in which none Mixing of colors and no color changes or stains caused by existing inclusions of the first rubber material in the outsole.

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An alternative embodiment of the device according to Fig. 1 is shown in Fig. K, in which after the blowing out of the compressed air introduced through the Forin-as shown in FIG. ' 3 but before the introduction of the second or. Outsole rubber measure the piston and cylinder assembly 18 has been actuated. To move the sole mold plate: 16 upwards until it has passed the compressed air inlet opening 32 but remains below the inlet opening 30 and is held there in the rest position. Then the. second or outsole rubber is injected into the mold 2k through the unclosed inlet opening 30j and the sole mold plate is then moved upward towards the midsole 28 in the manner already described.

In the alternative method of operation described above, it can be seen that the movement of the sole forming plate 16 to beyond the compressed air inlet and outlet openings prior to the injection of the second rubber compound into the forehead cavity 2k provides considerable security against clogging of the compressed air.

inlet and outlet openings is achieved.

After the second injection and the second pressing process in the one or alternatively other described way .and with the following sufficient period of time for the vulcanization process have the shape components as shown in Fig. 5

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the given position or location. When the work cycle is completed is j v / earth form ring and the complete shoe from each other deducted. When removing the shoe, you can possibly find the rancabquets formed by the second injection-compression molding are easily torn because they are with the bead 48 in the recess or ;. Groove 36 are connected. Should possibly when removing the shoe, pinched edges are not separated from the shoe in the manner described, in this way, these edge pinch-offs can then be separated very easily from the shoe along the weakened zone 50, which previously existed between the outsole and the M8 rubber bead. ■ ·

While the invention is based on an injection method for two different colored rubber compounds and a device has been described for this purpose, according to the invention, soles with three or more differently colored soles can also be used Make rubber rails. The invention can also be used are used for the molding of rubber articles that are not shoe soles. It is also not necessary that the Rubber is injected into the hollow mold, since any other introduction of the rubber into the hollow mold is possible. It can be seen that the method and apparatus according to the invention are particularly useful for the molding of rubber material on objects in a form, which is designed so that the object itself is part of the boundary of the hollow shape.

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Claims (9)

Claims J Method for molding objects, in particular soles for footwear, which have two differently colored rubber layers or areas, using a hollow mold with closed side walls, a device defining the molding surface and a movable molding element enclosed by the side walls for formation the lower surface of the mold, which mold member has a circumferential wall area for tight sliding guidance in the side walls of the mold and, pointing away from the lower surface of the mold, an adjoining circumferential groove, the rubber coat the mold are at different positions of the moving mold .gliedes successively in ¹ introduced, characterized in that the hollow mold is durchblas'en for removing loose particles _of% first rubber layer or sheet prior to the introduction of the second rubber layer. 2. The method according to claim 1, characterized that the first rubber layer into the mold through a first injection port and the second Rubber layer by a second spaced apart from the first Injection port to be injected while the injection of the air or the gas through a remote from the injection openings for the rubber compound third opening and «the discharge of gas or air through a fourth opening approximately in the same plane as the third opening, but far from this opening is made. 3. The method according to claim 1 and 2, characterized in that the movable mold member Moved at least into the plane of the third and fourth opening and blowing through in this position of the movable Shaped member is carried out. Yy. Method according to one of the preceding claims, characterized in that after blowing through the mold and before injecting the second rubber layer the .movable molded member in a plane between the second and the third or fourth opening is moved. 5. Device for performing the method according to one of the preceding claims, and for shaping or molding a two-tone sole on a listed shaft (upper leather) with a shaped ring for lateral delimitation a mold cavity limited at the top by the shaft or 309838/0802 Hollow mold, one held in a sliding manner in the mold cavity Sole mold plate, which is equipped with a device for up and Moving away is connected and one pointing against the shaft Surface and in the side wall a circumferential recess or groove and between this recess or empty Groove and the surface facing towards the shaft circumferential wall area for tight sliding guidance in the molding ring, wherein in the molding ring an 'injection , opening is provided for the introduction of the rubber, characterized in that next to the first inlet or injection opening (22) for "the rubber in the mold ring (12) a second opening" (Inlet opening 32) for blowing air or gas into the cavity or hollow mold (24) at high speed and a third opening (exit opening 3 * 0 for Discharge of the gas or the air from the mold cavity provided are. 6. Apparatus according to claim 5 ». characterized in that the inlet and outlet openings (32, 34) for the gas or the air essentially in the same plane and to achieve a flow through the entire mold cavity 'or hollow shape (24) are arranged far from each other and further away from the shaft (20) than the first entry or entry - 309838/0802 injection opening (22) for the rubber. 7. The device, dadu rch according to one of claims 5 or 6, that a fourth inlet is provided or injection opening (30) in the form of ring (12) for the introduction or injection of the second rubber compound. 8. Apparatus according to claim 7, characterized in that the fourth entry or injection opening (30) is located closer to the shaft (20) out than the inlet and outlet openings (32,3 ¹ O for the gas or air, but further from the Shaft removed as the first entry opening (22) for the first mass of rubber. '. 9. Apparatus according to claim 8, characterized in that the sole mold plate (16) movable away from the shaft (20) and towards it and in any intermediate position above and below the inlet and outlet openings (32, 3 * 0 as well as above the fourth inlet or outlet Injection opening (30) for the injection of the second rubber compound can be transferred. 303836/0802