JP2004351199A - Machining method of last for making shoe and numerically controlled machining center for the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method which rationalizes and speeds up a finishing process in a last production. <P>SOLUTION: The method comprises steps of positioning the last 1 in first movable fastening means 11a, 11b at a machining center 10, drilling a hole and making an identification mark thereon, positioning the last 1 in second movable fastening means 19, 20 of the center, and removing excess material in a process prior to the rough-machining. The numerically controlled machining center 10 comprises the fastening means 11a, 11b, 19, 20 of the last 1 and a plurality of drills 15, 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of processing a last for shoe production, and a numerically controlled machining center for implementing the method.

  One of the most important steps in shoe manufacturing is mold design and manufacture. This process distinguishes between those that are designed for the manufacture of soles and those that ultimately shape leather or other utilized materials to give the finished product its final appearance. It is necessary to.

  For this purpose, a mold, known as a last, is used which mimics the shape of the foot and is placed in the shoe during the shoe forming (alignment) process.

  The form of the last depends on the type or model of the shoe or on its different size. Thus, the amount of lasts to be made is substantial, especially at the start of a new area product campaign.

  The manufacturing process of the last starts with the design of the last with a computer-aided design tool and follows the programming of the numerically controlled machine. The machine is designed to start the processing of a work piece, usually of polyethylene, by roughing its surface. The rough cutting step is a step of fixing the work piece at two places, a step of rotating the work piece around an axis defined by the two fixed points, and a rough cutting blade to form a desired shape for the last. Machining the surface of the work piece to give it.

  In this step, two reference points or fastening points are marked on the toe and heel pad of the last. This will later serve to secure the last in other steps of the process.

  At the end of the first roughing step, the last is passed to another processing machine having smaller blades capable of polishing and improving the surface of the last for a more precise finish. In this step, the finishing machine fastens the last with the same point relative to the reference point initially marked by the first roughing machine, heel pad and toe.

  At this time, the last has a polished surface and a final curve, except for the toe and the heel pad, where the processing machine has fastened the last and the blade cannot operate. Therefore, there is a pair of surpluses projecting between 2 and 3 cm depending on the size or number.

  The next step in obtaining the final shape as a finished product for use in shoe making is either a manual operation or requires a person to directly manipulate other tools.

  First, it is manually cut using a saw to remove excess material protruding at the toe and heel pad of the last, and its surface is later polished to remove remnants.

  It is also necessary to make a diagonal cut to separate the instep part of the last. If the last is used to extend the skin of the shoe, it cannot be removed unless it is removed in front of the upper. This portion is threaded and secured to the spikes that hold itself down and cannot be removed until it is unscrewed.

  A pair of holes of different diameters are provided on the upper side of the last so that the spike can be threaded and a fastening ferrule that serves to fasten the last in a later step is attached. This operation also requires the action of an operator.

  In the next step, the foot size numbers (left and right) marked with the markers and the reference numbers of the models are manually labeled to identify the last.

  As a final step, framing of the last is performed in order to remove any padding that may be left in the last.

  It should be noted that the last step that has to be done to get a good finish of the last has to be done directly and manually at this time.

  To date, automation of these final steps in the last step manufacturing process has not been possible. As such, the time expenditure that would be spent manually performing all of these tasks is substantial.

  Processing machines exist for the production of physical prototypes of lasts. That is, the processing machine removes excess toe and heel pads, but they cannot be used in the manufacturing process because they take time to operate.

  There is another type of processing machine that removes toe excess by polishing, which is suitable for industrial production. However, those pressure fastening systems are not effective for some footprint designs.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a method that substantially streamlines and speeds up the finishing step of the last production.

  To this effect, the first aspect of the present invention includes a rough cutting step, a drilling step, an ID marking (marking) step, and a step of removing a surplus as a result of the rough cutting operation, and includes the following steps. A method of processing a last for the production of shoes is proposed.

a) The last is fixed in the numerically controlled machining center so that the last is fixed by fitting the housing present in the heel pad of the last and the surplus located at the toe with the first movable fastening means of the machining center. The process of positioning manually.
b) a step of drilling and ID marking of the last with a machining center drill while the last is fastened to the first movable fastening means and positioned.
c) Manually removing the last from the first movable fastening means, and manually inserting the last into the second movable fastening means of the machining center passing through an internal hole formed in the last in the step of performing the punching and ID marking. The process of fixing.
d) A step of removing surplus materials left freely by automatic machining with a drill.

  Because of these features, the finishing of the production of the last is performed in a substantially totally automated manner. The method consists of removing excess material, piercing the last, and marking the last. Thus, these three steps are performed in the same way and on the same machine.

  Preferably, the piercing operation of the last includes forming a plurality of holes in the bottom of the last, one hole in the instep, and two other holes of different diameters on the upper side.

  Three holes in the sole allow for rearward movement of the midsole of the shoe, and two holes on the upper side hold the last and serve to pass the fixed spikes on the part of the last that is cut. .

  Advantageously, the operation of positioning the last for the drilling step and the ID marking step is performed by rotating the last by the first movable fastening means.

  In this way, the drill can easily reach the entire surface of the last.

  Advantageously, the step of removing the surplus is carried out by fixing the last to the second movable fastening means by two holes having different diameters formed on the upper side thereof.

  In this way, the surplus is released from the first fastening means and can be removed by a simple repositioning of the footprint.

  In this case, preferably, the positioning of the last in the step of removing the surplus is performed by rotating the last by the second movable fastening means.

  As in the previous step, the drill can easily reach the two surpluses.

  According to one embodiment of the method, the first movable fastening means fixes the last in a horizontal position, and the second movable fastening means fixes the last in a vertical position.

  Advantageously, the rotation of the last by the first movable fastening means and the second movable fastening means takes place about a horizontal axis.

  Thus, it is not necessary to prepare two or more drills for processing the last in different steps.

  In another aspect, the invention is a numerically controlled machining center for a piercing step, an ID marking step, and a step of removing excess material resulting from a previous roughing step of a last for shoe making. A plurality of drills, first movable fastening means for fitting it to a housing in a surplus located at the heel pad and toe of the last, and its introduction internal hole formed in the last by the drill And a second movable fastening means for the machining center.

  In one embodiment of the machining center, the first movable fastening means includes a first support for its fit into the housing of the excess of the heel of the last and the pad and a housing of the excess of the last of the last of the last to the housing. A second support for its adaptation, both supports being variable in angle and the first support (11b) being able to rotate about its own axis.

  According to another embodiment, the second support (11a) can rotate around its own axis.

  Preferably, the second support is fixed to a height and depth adjusting means for accurately fastening the lasts of different sizes and types.

  Because of these features, the last can be suitably positioned before being machined, regardless of its shape or size.

  Advantageously, the height adjusting means has an endless screw operable by a rotating handle, and the depth adjusting means has a pneumatic piston operable by manual control.

  In this way, the step of placing the lasts in the machining center is maximized.

  Also advantageously, the support includes a pair of protrusions complementary to the last housing of the last.

  In this way, the last of the last is safe and secure, and it is avoided that the last moves relative to the fixing means during processing.

  Preferably, the second movable fastening means includes an arm including two cylinders having different diameters and rotatable around an axis, and the larger diameter cylinder includes a pressing means against a wall of a foot hole to be accommodated. In.

  In this case, the pressing means advantageously comprises a hollow shaft whose outer wall has a cross-sectional change, the cross-sectional change housing the piston of the pneumatic cylinder inside it, said piston being at its end. At the head with a skirt containing flexible wings, so that when the piston returns, the head is forced to move on the outer wall of the axle and the foot-shaped hole when reaching the cross-section change The fin expands against the wall.

  Thus, the last is firmly fastened and fixed during the removal of excess material, allowing for maximum working accuracy.

  Advantageously, the drill is replaceable.

  In this way, with only one drill holder, different drills can be used depending on the processing operation to be performed.

  Figures are appended for clarity of the foregoing description. They schematically show, by way of non-limiting example only, a practical example of an embodiment of the method and of the machining center according to the invention.

  In FIG. 1, the last 1 in the rough cutting process can be seen. In this step, the surface of the last 1 is processed by rotating a piece of polyethylene around an axis defined by two supports. These supports are housed in a pair of housings 2, 3 located on each of the toe and the heel pad to hold the last. Thus, in the area where these housings are located, the surpluses 4, 5 which have to be removed are left unprocessed.

FIG. 2 shows what will happen to the last 1 after going through the method of the invention.
As shown, the last 1 has already taken on its final shape, the surpluses 4, 5 have been removed and a pair of holes 6a, 6b, 6c, three other holes 6d are formed in the sole area. On the other hand, the size number 7 of the last 1 and other data on the last 1 are also displayed.

  The hole 6b formed on the upper side of the last 1 has a function for accommodating a spike holding a part of the upper 8 to be cut at a later stage to facilitate removal of the shoe.

  The hole 6a serves as a fixing means for the last 1 in a later manufacturing stage, and also serves to hold the last 1 in the process of the present invention as described later.

  The hole 6c is designed to facilitate removal of the upper 8 when the last is stored in the shoe.

  The hole 6d in the sole of the last 1 is used for inserting the metallic head screw later without penetrating it. The metallic head screw allows the introduction of the head such that it penetrates the inner sole of the plastic shoe and fast and accurately fixes it to the sole of the last. In this way, a new improvement is obtained in all steps of the shoe manufacturing process.

  Hereinafter, the steps performed for processing the last 1 will be described in detail.

  As can be seen in FIG. 3, the last is placed on the machining center 10 as shown. The center 10 is provided with first fastening means consisting of supports 11a, 11b which hold the last 1 by means of housings 2, 3 present in surpluses 4, 5 on each of the toes and heel pads. As explained above, these housings 2, 3 have already been used in the previous roughing step, so that no special machining of the housings 2, 3 is required for this step. In FIG. 4, details of the support parts 11a, 11b exhibiting the protruding parts 12 accommodated in the respective housings 2, 3 can be seen. In this way, the fixation of the last 1 is carried out in a consistent manner, whereby a trouble-free rotation takes place.

  In another embodiment shown in FIG. 5, the support 11a presents one cylindrical projection 12 which is housed in a complementary housing 2 in the toe excess 4 of the last 1. Therefore, the last 1 is rotated without requiring the rotation of the support 11a. Although the protrusion 12 in this embodiment is cylindrical, the shape may be conical or similar, which allows the last to rotate without any difficulty.

  The positioning of the last 1 in the machining center 10 is performed by an operator who adjusts the positions of the supporting portions 11a and 11b according to the size and characteristics of the last 1 in order to accurately position the last 1.

  For this purpose, these supports 11a, 11b have means for allowing their positions to be changed. Both supports 11a, 11b can vary in angle and can rotate about their own axis. The support 11a is also fixed to means allowing its own height and depth adjustment. This means comprises a pneumatic piston 13 for adjusting the depth and an endless screw 14 for moving the support 11a in the height direction by its own rotation. The piston 13 and the endless screw 14 are respectively operated by an operator using an operation lever and a rotation handle (not shown).

  In this way, the operator can position the last 1 quickly and effectively.

  When the last 1 is correctly positioned, the machining process starts. The drill 15 plays a role in processing the last and forms the hole shown in FIG. In order to reach different points on the surface of the last 1, the center 10 performs the necessary operations. In other words, the support portion 11b cooperating with the fourth axis of the machining center 10 rotates the last 1 by the operation of the motor 9, the movable bank 16 holding all the fixing devices of the last 1 horizontally moves itself, and The drill 15 moves vertically.

  In this way, the drill 15 can reach the entire surface of the last 1 and can form a hole without difficulty. In order to machine holes of different diameters or to perform ID marking of the last, the center 10 has additional drills 17 of different size and features, the most convenient in each case. Is used.

  At the end of this step, the last 1 already has all the necessary holes and ID markings (see FIG. 2).

  In the next stage, the surpluses 4, 5 of the last 1 are removed.

  For this purpose, the operator removes the last from the supporting portions 11a and 11b and, as shown in FIG. 7, rotates the horizontal axis around the fourth axis of the center 10 like the first supporting portion 11b of the first fastening means. Is fixed to the second fastening means located on the arm 18 which can rotate the footprint.

  The second fastening means (see FIG. 6) is constituted by a pair of cylinders 19 and 20 having different sizes. The fastening process is carried out by passing these cylinders 19, 20 through the holes 6b, 6a formed in the previous stage, so that the last 1 is in the vertical position.

  In order to effectively hold the last, the cylinder 20 is provided with pressing means against the inner wall of the hole 6a of the last 1 when the last 1 is passed through the cylinder.

  The operation of this means is illustrated in FIGS.

  When the last 1 is placed in the second fastening means, the cylinders 19 and 20 are passed through the holes 6b and 6a, respectively.

  The outer wall of the cylinder 20 is formed by a hollow shaft 21 having an extension 22. The shaft 21 houses the piston 23 inside. The piston 23 is associated with a pneumatic cylinder 24 and is connected at its end to a head 25 with a skirt formed by a flexible wing 26.

  When the last 1 is placed, the pneumatic cylinder 24 is operated, and the piston 23 is moved so as to pull the head 25 in order. When the head 25 reaches the extension 22, the wings 26 expand and they press against the inner wall of the hole 6a of the last.

  The removal of the surpluses 4 and 5 is performed in the same manner as in the first stage by the combined operation of the arm 18 (rotational movement), the movable bank 16 (horizontal movement) and the drill 15 (vertical movement) driven by the motor 9. Will be implemented.

  When the surpluses 4, 5 are removed, the last 1 already has a substantially final form, and all the necessary holes for the later stages are provided during the production run. , Are properly marked with ID and there is no surplus.

As described above, the method and machining center of the present invention provide some of the advantages of current footprint manufacturing systems, particularly those that need to be emphasized.
-Reduced control and calibration time with high machining accuracy and faithful duplication according to design.
-Reduced waiting time between machines and the better use of the factory area due to the possibility of doing more work on one machine.
-Reduction in the number of confirmations between operations.
Increased manufacturing flexibility in that it can be easily adapted to different types of embodiments to be manufactured.
A reduction in the number of rejections of the assembly as a result of a higher accuracy of the machine.
The elimination of the need for large amounts of tools, and consequent savings.
The possibility of implementing more complex geometric pieces more economically.
-During the machining process, the degree of two-way interaction between the machine and the operator is reduced and work safety in the facility is improved.
A reduction in the number of operators using the machine;

The following is a comparison table in which time is calculated for the manufacture of a pair of lasts, as currently performed and performed by the method of the present invention.
Current method:
Rough 1'30 of foot types in work time between <br/> irregular finish "
Finishing of the last 6'55 "
Marking, perforation and insertion of metallic case 45 '
Cut and polish excess heel pad 9'20 "

Cutting and spike threaded 3 between <br/> instep during the work '
Framing 20 "
Total time 21'50 "

New method:
Rough 1'30 of foot types in work time between <br/> irregular finish "
Finishing of the last 6'55 "
Drilling and marking of the last and rough cutting of excess toe and heel pads 2 '
Instep cutting, spike threading to hold the instep,
Insert a metallic case 3 '
Framing 20 "
Total time 13'45 "

The time difference between the two methods is 8 minutes or more for each pair of lasts. Therefore, in industrial production, the productivity is increased by the method of the present invention, which can be estimated to be very significant.

FIG. 1 shows the last before processing. FIG. 2 shows the footprint after processing. FIG. 3 is a diagram of the machining center and the last in the first processing stage. FIG. 4 is a detailed view of the first fastening means of the machining center. FIG. 5 is a detailed view of another embodiment of the first fastening means of the machining center. FIG. 6 is a detailed view of the second fastening means of the machining center. FIG. 7 is a diagram of the machining center and the last in the second machining stage. FIG. 8 is a schematic diagram showing the operation of the second fastening means of the machining center. FIG. 9 is a schematic diagram showing the operation of the second fastening means of the machining center.

Claims (16)

A method of processing a last (1) for shoe production, comprising a rough cutting step, a drilling step, an ID marking step, and a step of removing a surplus (4, 5) resulting from the rough cutting operation,
a) Fit the housings (2, 3) in the surplus (4, 5) located on the heel pads and toes of the last (1) with the first movable fastening means (11a, 11b) of the machining center (10). Manually positioning the footprint (1) in the numerically controlled machining center (10) so as to fix the footprint (1),
b) a step of piercing and ID marking of the last (1) by the drill (15) of the machining center (10) while the last (1) is held and positioned by the first movable fastening means (11a, 11b). When,
c) The footprint (1) was previously formed on the footprint (1) in the step of performing the perforation and ID marking while manually removing the footprint (1) from the first movable fastening means (11a, 11b). Manually fixing to the second movable fastening means (19, 20) of the machining center (10) passing through the internal holes (6a, 6b);
d) a step of removing freely leftovers (4, 5) by automatic machining with a drill (15);
A method comprising: The drilling operation of the last (1) includes a plurality of holes (6d) on the bottom of the last (1), a hole (6c) on the instep, and two other holes (6a, 6. The method according to claim 1, comprising the step of processing 6b). The operation of positioning the last (1) for the punching and ID marking process is performed by rotating the last (1) by the first movable fastening means (11a, 11b). Item 3. The method according to Item 2. In the step of removing the surplus (4, 5), the last (1) is fixed to the second movable fastening means (19, 20) by two holes (6a, 6b) having different diameters formed on the upper side thereof. The method according to claim 2, wherein the method is performed. 5. The method according to claim 4, wherein the step of removing the surplus (4, 5) is performed by rotating the last (1) with the second movable fastening means (19, 20). the method of. The first movable fastening means (11a, 11b) fixes the last (1) in a horizontal position, and the second movable fastening means (19, 20) fixes the last (1) in a vertical position. The method according to any one of claims 1 to 5, wherein Method according to claim 6, characterized in that the rotation of the last (1) by the first movable fastening means (11a, 11b) and the second movable fastening means (19, 20) is performed about a horizontal axis. Numerically controlled machining center (10) for the step of punching, ID marking, and removing excess material (4, 5) as a result of the previous roughing step of the last (1) for shoe production And
Multiple drills,
First movable fastening means (11a, 11b) for fitting them to the housing (2, 3) in the surplus (4, 5) located on the heel pad and toe of the last (1);
Second movable fastening means (19, 20) for their introduction internal holes (6a, 6b) formed in the last (1) by the drill (15);
A machining center comprising: The first movable fastening means (11a, 11b)
A first support (11b) for their fit of the heel pad surplus (5) of the last (1) to the housing (3);
A second support (11a) for their fitting of the toe excess (4) of the last (1) to the housing (2);
Has,
9. Center (10) according to claim 8, characterized in that both supports (11a, 11b) are variable in their angle and are rotatable about their own axis. Center (10) according to claim 9, characterized in that the second supports (11a) are rotatable about their own axis. The second support part (11a) is fixed to height and depth adjusting means (13, 14) for accurate fixing of lasts (1) of different sizes and types. The center (10) according to item 9 or 10. The height adjusting means includes an endless screw (14) that can be actuated by a rotating handle,
12. Center (10) according to claim 11, wherein the depth adjusting means comprises a pneumatic cylinder (13) that can be actuated by a handwheel. The support (11a, 11b) comprises a pair of protrusions (12) complementary to the housing (2, 3) of the surplus (4, 5) of the last (1). Item 10. The center (10) according to item 9. The second movable fastening means (19, 20) includes an arm (18) including two cylinders (19, 20) rotatable about an axis and having different diameters,
9. Center (10) according to claim 8, characterized in that the larger diameter cylinder (20) comprises pressing means against the wall of the hole (6a) of the footprint (1) to be accommodated. The pressing means includes a hollow shaft (21) whose outer wall has a cross-section changing portion (22),
The cross-section changing portion (22) houses the piston (23) of the pneumatic cylinder (24) inside thereof,
Said piston (23) is connected at its end to a head (25) provided with a skirt comprising a flexible wing (26),
It forces the head (25) to move on the outer wall of the shaft (21) when the piston (23) returns, and when it reaches the section change (22), the hole (6a) in the last (1). 9. The center (10) according to claim 8, wherein the wing (26) is extended with respect to the wall of (8). Center (10) according to any of claims 8 to 15, wherein the drills (15, 17) are replaceable.

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