JPS6028483B2 - Method and device for manufacturing footwear soles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for forming footwear soles.

When manufacturing the bottom of a shoelace from plastic, such as vinyl chloride, it is recommended to include a filler, such as cork, in the bottom to make it lighter and cheaper. This is a commonly used method.

One method of manufacturing soles with built-in filler is to attach the filler to the upper part of the molding, for example using hooks extending downward from the last, and then wrap the sole around the sides and outer surface of the filler. It consists of a molding process. One of the disadvantages of such a method is that the filler may move when injection molding plastic materials under pressure. Furthermore, in the resulting product, although the plastic sole around the filler is connected to the upper part of the shoe, there is no adhesive force between the top surface of the filler and the molded upper. An object of the present invention is to provide a molding method and a molding apparatus in which a filler material directly attached to the upper part of a shoe, etc. is substantially surrounded by a sole incorporated inside the molded sole. The aim is to avoid the disadvantages of

Therefore, the present invention forms a first bottom portion on the bottom surface of the filler in a first forming step, and a second bottom portion is formed around the sides of the first bottom portion and on the top and sides of the filler in a second forming step. A method of forming a sole for footwear is provided.

The present invention further provides an apparatus for carrying out the above method, comprising a movable bottom forming piston, a movable mold side, and a recess on the outer surface of the forming piston for receiving the filler. and a fake shoe last that forms a first molding cavity together with the side part of the mold, and a cotton-attached last that holds the upper part of the shoe and forms a second molding cavity together with the molded first sole part and the molded side part. The present invention provides a device consisting of:

The molded first bottom portion becomes an insert consisting of a filler material and a plastic molding layer molded onto the bottom surface of the filler material. More specifically, during the manufacture of footwear soles, a pseudo last disposed on a rotatable last holder is initially placed in a loading position to receive a filler material.

After inserting the filler material into the recess of the fake last, the last holder is rotated 180 degrees and lowered to close the mold sides and form a first mold cavity with the bottom molding piston and the fake last. . A first injection molding of the thermoplastic material is performed to form a first partial shell insert. Following the curing or solidification period, the last retainer is raised and rotated 180 degrees to open the mold sides, the bottom mold piston is raised with the insert, the mold sides are closed, and the last retainer is closed. The last and the upper part of the shoe or similar covering material are placed in a second molding position with the last part facing down. In this second molding position, a second molding cavity is formed by the insert, the mold sides and the shoe upper structure on the tightening mold. A second injection molding operation is performed to produce a complete sole on the shoe upper structure. Following the final curing step, the mold is opened. That is, the shoe last holder is raised, the sides of the mold are opened, and the processed product is taken out. The finished product consists of a first sole part, a second sole part surrounding the sides and top of the insert, and a shoe upper structure.

When manufacturing sandals, the inner sole with the laces is placed directly under the tightening last during a second forming operation. Of course, the tightening last and the inner sole can also be replaced by a conventional sole with an upper, in which case the sole is molded directly onto the upper of the shoe. Accordingly, as used herein and in the claims, the phrase "shoe upper" refers to, for example, the shoe upper that is placed between the vertical last and the mold sides during the second molding operation. Or it means an object like the inner sole.
Using the method and apparatus described above, it is possible to produce filled molded soles in which the filler is connected directly to the injected plastic during each of the two injection steps.

When using cork fillers and polyvinyl chloride or similar plastics, the cork is pre-adhesive by soaking it in a plastic adhesive such as polyurethane. During the first molding step, the filler material is held in the recess within the fake last, so that the filler material cannot move. Therefore, the position of the filler inside the fabricated sole is constant and the same amount of plastic surrounds the filler from one sole to the next. The plastic used for the insert is generally a different color than the plastic used in the second molding step, and the plastic used in the second step forms a decorative band around the insert and covers the top of the insert. Another important feature of the invention is the molding of decorations in the first molding step, which decorations appear on the outer surface of the decorative band after the second molding step. It is common to apply decorative bands, decorative circles, or other decorations to decorative bands on the finished soles of articles such as footwear, such as basketball shoes or boots. By providing a suitable recess in the simulated last used in the first molding step and in part of the side of the mold, the insert produced in the first step can be given the desired shape, for example a circle or a maple leaf shape. It is also possible to provide a protrusion extending outwardly. In a second molding step, a different portion of the mold side is used to mold the plastic material around the protrusion to expose the outer surface of the protrusion on the machined bottom. Accordingly, the present invention provides an insert formed from a filler of a lightweight material, a first plastic bottom portion molded into the bottom of the filler and extending outwardly beyond the edges of the filler; at least one ear projecting upwardly from and integral with at least one side of the bottom portion; a projection extending outwardly on the ear; and a second plastic bottom portion surrounding the top and sides of the insert. To provide a sole for footwear, characterized in that the protrusion extends outwardly through the second sole part, and the outer surface of the L protrusion is exposed on the outside of the sole.

The invention will now be described in more detail with reference to the accompanying drawings, which illustrate preferred embodiments of the invention.

The device according to the invention is disclosed in the application filed in 1973 by the applicant.
It can be used in a variety of molding machines, including the molding machine disclosed in Canadian patent application Ser. Accordingly, the device according to the invention can also be used with a single-station molding machine and with a multi-station molding machine, so long as the molding machine is intended for use with at least one last holder and mold as described below. It can also be used. 1 and 2, an injection molding machine incorporating a device according to the invention, as disclosed in the specification of the above-mentioned patent application, supports a rotatable turntable 2. It has a support part 1.

The turntable 2 is generally circular and is provided with six molds 3 that receive liquid plastic material from a pair of extruders 4. Powdered or granular plastic material (in this example polyvinyl chloride) is fed into a hopper 5 at one end of each extruder 4 and passes in liquid form through a discharge head 9 into a mold 3. It comes out at one end. In the center column 8 above the turntable 2, there are 60
6 shoe last holders 10 that form a degree angle and light up
is located.

Each last holder 10 has a camouflage last 1 on one side 12 thereof.
1 and a tightening last 13 on the opposite side 14 of the retainer (not shown in FIG. 1). Last holder 1 is rotatable and can slide vertically on column 8, so that lasts 11 and 13 can be moved into position to form mold cavities, which will be described in detail below. . In most of the outer regions of the fake last 11 (see FIGS. 3 to 7 and 9) there are recesses 15 for receiving fillers 16 made of cork or a lightweight material such as plastic, for example.

The cotton last 13 is used to attach the inner sole 1 to the top of the mold during the second molding operation.
7 (see Figure 5) is a thick plate in the shape of a shoe sole.
For ease of explanation, the description of the preferred embodiment is as follows:
It should be noted that the invention is limited to the production of sandals requiring a simple inner sole 17. However, in the case of a shoe or boot that has an upper construction rather than an inner sole and laces, the cotton last and inner sole are replaced by molded upper sides. Each shoe last 1
1 and 13 are provided with an internally threaded sleeve 18 that receives one end of a threaded shaft 19 extending inside the knurled nut 20 . One more
A real threaded shaft 22 is attached to a jagged nut 2
0 to an internally threaded sleeve 23 above a plate 24 on the last support 10 . Each mold 3
has a pair of mold sides 25 that are laterally movable between open and closed positions and a mold piston 26 that is vertically movable.

The mold side 25, mold piston 26, and either last 11 or 13 cooperate to form a mold cavity as described below. In order to produce soles for sandals using the device according to the invention, a fake shoe mold 1
1 in the upper position (see FIG. 3), and place the filler 16 inside the recess 15.

The recess 15 is small enough that the filler 16 fits neatly and does not fall out when the last retainer 10 is rotated. As mentioned above, the fake last 11 is placed on the molding station 28 (see FIG. 2) of a six-station molding machine. At the molding station 2M, the molding piston 26'
In the raised position, the mold sides 25 are in the open position or spaced apart position. After loading the filler 16 (see FIG. 3), the molding piston 26 is lowered and the last retainer 10 is
It is rotated 80 degrees and lowered, bringing the mold sides 25 together into the molding position to form a first mold cavity. The mold 3 and last holder 10 are rotated as an integral unit to a molding station 32 where thermoplastic material is injected from one of the extruders 4 through the mouth 33 into the molding cavity to form an insert 34. (See Figure 4). The insert 34 consists of a filler material 16 and a first bottom part 35 made of thermoplastic material injected into the mold cavity. Turn the turntable 3 again while keeping the mold closed, and close the mold 3.
is moved to station 36 where the first bottom portion 35 within the mold is allowed to cool. The next process is molding station 37
This step is a step of opening the mold 3 by raising the fake shoe last 11 and moving the mold side 25 to the open position. When the mold 3 is opened, the insert 34 formed during the first molding operation is retained on the piston 26. While being held at station 37, the last holder 10 is rotated 180 degrees so that the vertical last 13 is on top of the last 3.

The molding piston 26 is raised and the mold side 25 is closed. The inner sole 17 of the sandal with the toe lace 40 and seed lace 41 attached to the inner sole is placed in the mold side 25 within the upper recess defined in the shoulder 42 of the mold side. The tightening last 13 is lowered to the inner sole 17, the mold 3 is rotated to the station 43, where a second injection molding is carried out, and the insert 34 is passed from the second extruder 4 through the molding opening 44. , the mold side part 25 , and the tightening shoe last 1
Thermoplastic material is injected into the second mold cavity formed by the inner bottom 17 on the bottom of the second bottom portion 45 . A second bottom portion 45 covers the insert 34 and connects it to the inner sole 17. The turntable 8 is then rotated and the mold 3 is moved to the station 46 for cooling the second bottom part 45. The sandals are now completed, and the remaining operations are to rotate the turntable 8, move the mold 3 to the station 28' again, open the mold, remove the processed sandal, and repeat the above steps. In the above explanation, for one type 3,
Explained the operation of the molding machine.

The same process is performed on each mold on the turntable 2. Of course, it is also possible to have only one mold in one location and complete the molding and curing process in the same order as above, but a multi-stacking machine is preferred to increase production efficiency. In order to carry out the connection operation, after placing the filler material on each fake shoe last, the above-described continuous operation consisting of a first molding operation and a second molding operation is carried out by two operators. That is, one operator at station 28 places the filling material on the fake last, rotates the last holder so that the last is on top of mold 3, takes out the finished sample, and transfers it to station 37. A second operator rotates the last holder so that the tightening last is at the top of the mold and places the inner sole 17 on the mold sides 26.
The apparatus according to the invention can be used to produce soles for various types of footwear.

Basically, the device and the method according to the invention are intended to produce two-color soles by using plastic materials extruded from two extruders 4, 4 respectively with different colors. The outer sole or insert is of one color and the decorative band around the inner and outer soles is of the other color. With reference to FIGS. 8 to 12,
Examples of particularly preferred soles are described below.

As mentioned above, the decorative bands of basketball shoes are typically decorated by painting or otherwise. Using the mold described below, the insert of the first color, i.e. the outer sole, is molded and then the insert is shaped so that the pattern of the desired shape protrudes from one or more parts of the insert through the decorative band. A decorative band of a second color can be formed around the . Wherever possible, the same reference numerals are used in FIGS. 8-12 to refer to the same or similar parts as used in FIGS. 3-7. The mold side parts 25 used to achieve the above purpose have the following features, except that each mold side part 25 is provided with a plurality of maple leaf-shaped recesses 47 with tapered sides. This is the same as the side part of the mold shown in FIGS. 3 to 7.

A cylindrical blind hole 48 for receiving a pin 50 having a hexagonal cross section is provided on the inner surface of each recess 47 (see FIG. 10). The length of the pin 50 is not as long as the depth of the blind hole and is inserted into the blind hole so that the patterned portion of the insert can be easily removed after the first molding operation.
Since the blind hole 48 is cylindrical and the pin 60 has a hexagonal cross section, air is compressed inside the blind hole during injection molding of the first bottom portion 35, and subsequent to the first molding operation, air is compressed inside the blind hole. The insert can be easily removed from the mold cavity. A recess 47 is provided on the outer side of the fake shoe last 11.
A first bottom portion 35 of the insert 34 (see FIG. 12) formed by the first molding step extends upwardly from the base 55 and has an outwardly extending maple leaf. It has an integral structure with a shaped protrusion 56 and a plastic ear support post 54 that supports the protrusion. During the first molding operation, the upper part of the molding piston (not shown) is located in the middle of the mold 25 at a height 58 below the recess 47, and the bottom surface of the fake last 11 is located in the recess 47. Located at a lower height 60, a thin base 55 is placed on the bottom surface of the filling material (not shown in FIGS. 8-10) filled in the recess 14.
is formed. During the second molding operation, the upper surface of the molding piston is located at shoulder 62 inside mold side 45 . The insert 34 is thus inserted by the mold piston, the mold side and the inner sole 17 which is placed in the recess defined by the shoulder 42 in the mold side and is clamped by the cotton last 13. located within the upper mold cavity to be formed. The sole manufactured in the apparatus shown in FIGS. 8-10 has a plurality of protrusions 56 extending outwardly through the sides of the decorative band portion of the second sole portion 45.

It is clear that only one ear and projection can be provided and the shape of the projection can be varied depending on the desired appearance of the machined sole. In the foregoing, a method and apparatus for manufacturing a footwear sole having an insert containing a filler material substantially surrounded by plastic and molded directly into the sole of a shoe upper structure or the like is described. added.

[Brief explanation of the drawing]

FIG. 1 is an elevational view of an injection molding machine that can be used with an apparatus according to the invention. FIG. 2 is a schematic plan view of the molding machine shown in FIG. 1. 3 to 7 show a last retainer of the device according to the invention;
It is an explanatory view showing a part of a shoe last and a mold in cross section. FIG. 8 is a plan view of a mold and a fake shoe mold used in the apparatus shown in FIGS. 3 to 7. FIG. FIG. 9 is a cross-sectional view taken approximately along the line K-X in FIG. 8. Figure 10 shows the 8th
It is an enlarged wisteria sectional view taken approximately along the line XX in the figure. FIG. 11 is an elevational view of a sandal made using the method and apparatus according to the present invention. FIG. 12 is a cross-sectional view taken approximately along the skin line of FIG. 11. 11・
... Disguise shoe last, 13... Vertical shoe last, 16... Filler, 26... Molding mold side part, 26... Molding piston,
35...first bottom part, 45...second bottom part. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12

Claims (1)

[Scope of Claims] 1. A method for forming the sole of footwear containing a filler, which comprises: forming a first bottom portion on the bottom surface of the filler in a first forming operation; and forming a first bottom portion on the bottom surface of the filler in a second forming operation. molding a second bottom part around the sides of the first bottom part and onto the top and sides of the filler. 2 The first sole part is molded in the first molding cavity formed by the fake shoe last that stores the filler, the first part of the side of the mold opposite thereto, and the bottom molding piston, and the first sole part is molded to tighten the shoe. in a second mold cavity formed by the upper or similar part of the shoe on the mold, the second part of the mold side, the filler material and the first sole part placed on the mold piston; A method according to claim 1, characterized in that the second bottom part is molded. 3 A device for forming the bottom of footwear containing a filler, which includes a vertically movable bottom forming piston, a movable mold side, and a recess for receiving the filler in the bottom surface. a camouflage last having a molding piston and forming a first molding cavity with a first portion of said mold side; and a first sole portion holding an upper or similar portion of the shoe and molded within the first molding cavity. and a filler material on the first sole portion and a tightening last forming a second mold cavity together with the second portion of the mold side and the upper part of the shoe or similar part. 4. said first portion of said mold side and said last having a complementary recess forming a protrusion on said first sole portion molded in a first mold cavity; 4. The device of claim 3, wherein the protrusion extends through a decorative strip molded around the bottom portion and filler. 5 A rotatable and vertically movable shoe last holder that holds the fake shoe last and the tightening shoe last, and the fake shoe last and the tightening shoe last are alternately placed on the side of the mold above the molding piston. 5. The apparatus according to claim 3, wherein the apparatus is configured such that the first molding cavity and the second molding cavity can be formed by positioning the molding cavity in the molding cavity.