U.S. patent application number 10/822031 was filed with the patent office on 2004-10-14 for machining method of a last for making shoes and machining centre by numerical control to carry out this method.
This patent application is currently assigned to Carpe Investigaciones Cientificas, S.L.U.. Invention is credited to Pons, Antoni Vidal.
Application Number | 20040200014 10/822031 |
Document ID | / |
Family ID | 32865091 |
Filed Date | 2004-10-14 |
United States Patent
Application |
20040200014 |
Kind Code |
A1 |
Pons, Antoni Vidal |
October 14, 2004 |
Machining method of a last for making shoes and machining centre by
numerical control to carry out this method
Abstract
The method comprises the steps of positioning of the last (1) in
first fastening means (11a, 11b) at the machining center (10),
piercing and identification marking of it, positioning of the last
(1) in second fastening means (19, 20) of the center, and removal
of the surpluses (4, 5) of a process previous to the rough-hewn.
The machining center by numerical control (10) comprises fastening
means (11a, 11b, 19, 20) of the last (1), and a number of drills
(15, 17).
Inventors: |
Pons, Antoni Vidal;
(Binissalem, ES) |
Correspondence
Address: |
STEINBERG & RASKIN, P.C.
1140 AVENUE OF THE AMERICAS, 15th FLOOR
NEW YORK
NY
10036-5803
US
|
Assignee: |
Carpe Investigaciones Cientificas,
S.L.U.
|
Family ID: |
32865091 |
Appl. No.: |
10/822031 |
Filed: |
April 9, 2004 |
Current U.S.
Class: |
12/145 |
Current CPC
Class: |
A43D 3/02 20130101; B27M
3/20 20130101 |
Class at
Publication: |
012/145 |
International
Class: |
A43D 095/00; A43D
029/00; A43D 031/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 10, 2003 |
EP |
03380091.3 |
Claims
1. Machining method of a last (1) for the production of shoes,
which comprises the rough-hewn, piercing, identification marking,
and removal of the surpluses (4, 5) operations resultants of the
rough-hewn operation, comprising the following steps: a) Manual
positioning of the last (1) in a machining center by numerical
control (10), fixing it by fitting the last in housings (2, 3) in
the surpluses (4, 5) located in the heel-pad and in the toe of the
last (1) and first movable fastening means (11a, 11b) in the
machining center (10). b) Piercing and identification marking of
the last (1) by a drill (15) of the machining center (10), the last
(1) being held and positioned by said first movable fastening means
(11a, 11b). c) Manual removal of the last (1) from the first
movable fastening means (11a, 11b) and manual fastening of it to
second movable fastening means (19, 20) in the machining center
(10) that introduces inside holes (6a, 6b) made previously in the
last (1) in the step of piercing and identification marking. d)
Removal by automatic maching, by means of the drill (15), of the
surpluses (4, 5) that have been left free.
2. Method, according to claim 1, wherein the operation piercing of
the last (1) comprises the machining of a plurality of holes (6d)
in the sole of the last (1), a hole (6c) in the instep shoulders,
and other two holes (6a, 6b) of different diameter in its
upside.
3. Method, according to claim 2, wherein the positioning operation
of the last (1) for its piercing and its identification marking is
carried out rotating the last (1) by means of the first movable
fastening means (11a, 11b).
4. Method, according to claim 2 wherein the removal process of the
surpluses (4, 5) is carried out fixing the last (1) by the two
holes of different diameter (6a, 6b) made in its upside to the
second movable fastening means (19, 20).
5. Method, according to claim 4, wherein the positioning of the
last (1) in the removal step of the surpluses (4, 5) is carried out
rotating it by means of the second movable fastening means (19,
20).
6. Method, according to claim 1, wherein the first movable
fastening means (11a, 11b) fix the last (1) on an horizontal
position and the second movable fastening means (19, 20) fix the
last (1) on a vertical position.
7. Method, according to claim 6, wherein the turn of the last (1)
by the first movable fastening means (11a, 11b) and by the second
movable fastening means (19, 20) is carried out about an horizontal
axis.
8. Machining center by numerical control (10) for piercing,
identification marking, and removal of the surpluses (4, 5)
resultants of a previous rough-hewn process of a last (1) for the
production of shoes, wherein it comprises a plurality of drills
(15, 17), first movable fastening means (11a, 11b) for their
fitting in housings (2, 3) in the surpluses (4, 5) located in the
heel-pad and in the toe of the last (1), and second movable
fastening means (19, 20) for their introduction inside holes (6a,
6b) made in the last (1) by a drill (15).
9. Center (10), according to claim 8, wherein the first movable
fastening means (11a, 11b) comprise a first support (11b) for their
fitting in the housing (3) of the surplus (5) of the heel-pad of
the last (1), and a second support (11a) for their fitting in the
housing (2) of the surplus (4) of the toe of the last (1), both
supports (11a, 11b) being able to vary their angle and being able
to rotate about the first support (11b) about their own axis.
10. Center (10), according to claim 9, wherein the second support
(11a) can rotate on their own axis.
11. Center (10), according to claims 9, wherein the second support
(11a) is fixed to means (13, 14) for its height and depth
regulation for the correct fastening of lasts (1) of different
sizes and types.
12. Center (10), according to claim 11, wherein the height
regulation means comprise an endless screw (14) which can be
operated by a rotatory handle, and the depth regulation means
comprise a pneumatic cylinder (13) which can be operated by a
manual handle.
13. Center (10), according to claim 9, wherein the supports (11a,
11b) include a pair of protrusions (12) complementary to the
housings (2, 3) of the surpluses (4, 5) of the last (1).
14. Center (10), according to claim 8, wherein the second movable
fastening means (19, 20) comprise an arm (18), which can rotate
about an axis, which includes two cylinders (19, 20) of different
diameter, the cylinder of greater diameter (20) including pressing
means against the walls of the hole (6a) of the last (1) in which
is housed.
15. Center (10), according to claim 14, wherein the pressing means
comprise a hollow shaft (21) whose external walls present a
cross-section change (22), which houses inside it a piston (23) of
a pneumatic cylinder (24), said piston (23) being connected on its
end to a head (25) provided with a skirt which includes flexible
wings (26), so that when the piston (23) strikes back, it forces
the head (25) to travel over the external walls of the shaft (21),
so that it arrives to the cross-section change (22) the wings (26)
are expanded, against the walls of the hole (6a) of the last
(1).
16. Center (10), according to claim 8, wherein the drills (15, 17)
are interchangeable.
Description
[0001] The present invention refers to a machining method of a last
for making shoes and to a machining centre by numerical control to
carry out this method.
BACKGROUND OF THE INVENTION
[0002] One of the most important processes in the production of
shoes is the design and production of moulds. In this process it is
necessary to distinguish among the designed for the production of
the shoe sole and those that finally will give form to the skin or
other utilized materials to give the final aspect to the finished
product.
[0003] For this last purpose moulds known as lasts are used, that
imitate the form of the foot and are placed inside the shoe during
its conformation process.
[0004] The form of the last will depend on the shoe type or model,
or on the different sizes. For this reason, the quantity of lasts
that should be made can become considerable, especially in
launching campaigns of new ranges of products.
[0005] The production process of the lasts begins with the design
of them with computer assisted design tools and then programming a
numerical control machine. This machine takes charge to begin the
machining of a piece, usually of polyethylene, by means of the
rough-hewn of its surface. The rough-hewn consists on fixing the
piece by two points, making it rotate about the axis defined by
these two fixing points, and, by means of rough-hewn blades,
machining the surface of the piece to give it the desired form to
the last.
[0006] In this process the two reference or fastening points are
also marked in the toe and in the heel-pad of the last, which will
serve to fix it later on in other steps of the process.
[0007] Once it is finished the first rough-hewn process, the lasts
pass to another machine for a more precise finishing, with smaller
blades with the capacity to polish and to improve the surfaces of
the last. In this process, the finishing machine fastens the lasts
by the same points, heel-pad and toe, respecting the reference
points marked initially by the first rough-hewn machine.
[0008] In this point, a last is obtained with the polished surfaces
and the definitive curves, except in the toe and the heel-pad,
points where the machine fastens the lasts and the blades cannot
act, so that there are a pair of surpluses that protrude between
two and three centimeters according to the size or number.
[0009] The following steps to obtain the definitive shape, as
finished product for the use in the production of shoes, are manual
tasks or they need directly the manpower to operate other
tools.
[0010] In the first place, to eliminate the surpluses that protrude
in the toe and in the heel-pad of the last, it is cut hand-operated
with the help of a saw, polishing the surface later on to eliminate
remains.
[0011] It is also necessary to make an oblique cut that separates
the part of the instep of the last, since once this is used to
stretch the skin of the shoe, it would not be possible its
extraction if it is not taken out before the part of the instep.
This piece is fixed threading a spike that presses it and that it
does not allow its extraction until it is not unthreaded.
[0012] To be able to thread the spike, and to mount a fastening
ferrule which will serve to fasten the last in later steps, there
are carried out a couple of holes of different diameter in the
upside of it. This operation also requires de the action of an
operator.
[0013] In a following step, the last is identified labeling by hand
the foot size number (left and right) marked with a marker and the
reference of the model.
[0014] As last step, it is carried out the flaming of the lasts,
with the objective of eliminate the filings which could left on
it.
[0015] As it can be observed, the last steps that must be done to
obtain an excellent finishing of the lasts, at the moment need the
direct manpower to be carried out.
[0016] Until the present time, they have not still been possible to
automate these last steps of the manufacturing process of the
lasts, so that the time consumption that supposes to have to carry
out manually all these operations is considerable.
[0017] Machines exist for the manufacturing of physical prototypes
of lasts that, although they eliminate the surpluses of the toe and
the heel-pad, they cannot be used in production processes, due to
their high maneuver times.
[0018] There also exists another type of machine for the removal of
the surplus of the toe by means of polishing, which are feasible
for the industrial production. However, their fastening system, by
means of pressure, it is not valid for some last designs.
DESCRIPTION OF THE INVENTION
[0019] The object of the present invention is to provide a method
that substantially simplifies and speeds up the finishing process
in the last production.
[0020] To this effect, a first aspect of the invention proposes a
machining method of a last for the production of shoes, which
comprises these operations: rough-hewn, piercing, identification
marking, and removal of the resulting surpluses of the rogh-hewn
operation, which it is characterized in that it comprises the
following steps:
[0021] a) Manual positioning de the last in a machining center by
numerical control, fixing it by fitting the housings present in the
surpluses located in the heel-pad and in the toe of the last and
first movable fastening means in the machining center;
[0022] b) Piercing and identification marking of the last by means
of a drill in the machining center, the last being fastened and
positioned by said first movable fixing means;
[0023] c) Manual extraction of the last of the first movable fixing
means and manual fastening of it to second movable fastening means
in the machining center, which introduce inside holes made
previously in the last in the step of piercing and identification
marking;
[0024] d) Removal by automated machining, by means of the drill, of
the surpluses which remain free.
[0025] Thanks to these characteristics, the finishing process in
the production of the last it is carried out practically in its
entirety in an automated way. The method comprises the removal of
the surpluses, the piercing of the last, and its marking.
Therefore, they are carried out three operations in the same method
and in the same machine.
[0026] Preferably, the piercing operation of the last comprises the
machining of a plurality of holes in the sole of the last, a hole
in the shoulder of the instep, and other two holes of different
diameter in its upside.
[0027] The three holes of the sole will allow the later placement
of the insole, and the two holes of the upside will serve to hold
the last and to introduce a fastening spike of a part of the last
that will be cut.
[0028] Advantageously, the positioning operation of the last for
its piercing and its identification marking is carried out rotating
the last by means of the first movable fastening means.
[0029] This way, the drill will be able to access easily to the
whole surface of the last.
[0030] Also advantageously, the removal process of the surpluses is
carried out fixing the last by the two holes of different diameter
practiced in its upside to the second movable fastening means.
[0031] This way, the surpluses are liberated of the first fastening
means and they can be eliminated by means of a simple change of
position of the last.
[0032] In this case, preferably, the positioning of the last in the
removal step of the surpluses is carried out rotating it by means
of the second movable fastening means.
[0033] As in the previous step, the drill can access easily to the
two surpluses.
[0034] According to an embodiment of the method, the first movable
fastening means fix the last in an horizontal position and the
second movable fastening means fix the last in a vertical
position.
[0035] Advantageously, the turn of the last by the first movable
fastening means and by the second movable fastening means is
carried out about an horizontal axis.
[0036] This way, it is not necessary to prepare more than a drill
to mechanize the last in the different steps.
[0037] In another aspect, the invention provides a mechanization
center by numerical control for the piercing, identification
marking, and removal of the resulting surpluses of a previous
rough-hewn process, of a last for the production of shoes, which is
characterized in that it comprises a plurality of drills, first
movable fastening means for its fitting in housings present in the
surpluses located in the heel-pad and in the toe of the last, and
second movable fastening means for its introduction inside holes
made in the last by a drill.
[0038] In an embodiment of the machining center, the first movable
fastening means comprise a first support for its fitting in the
housing of the surplus of the heel-pad of the last, and a second
support for its housing for its fitting in the housing of the
surplus of the toe of the last, being both variable supports in
angle and being able the first support (11b) to rotate about its
own axis.
[0039] According to another embodiment, the second support (11a)
can rotate about its own axis.
[0040] Preferably, the second support is fixed to height and depth
regulation means for the correct fastening of different sizes and
types of the lasts.
[0041] Thanks to these characteristics, the last can be suitably
positioned independently of its form or size before being
machined.
[0042] Advantageously, the height regulation means comprise an
endless screw which can be driven by means of a rotating handle,
and the depth regulation means comprise a pneumatic piston which
can be driven by means of a manual control.
[0043] This way, it is facilitated to the maximum the placement
process of the last in the machining center.
[0044] Also advantageously, the supports includes a couple of
complementary protrusions to the housings of the surpluses of the
last.
[0045] This way, the subjection of the last is safe and solid,
avoiding that it moves with regard to the fastening means during
the machining.
[0046] Preferably, the second movable fastening means comprise an
arm, with ability of rotate about an axis that includes two
cylinders of different diameter, including the cylinder of greater
diameter pressure means against the walls of the hole of the last
in which is housed.
[0047] In this case, advantageously, the pressure means comprise a
hollow shaft whose external walls present a section change that
houses inside it a piston of a pneumatic cylinder, being connected
this piston at its end to a head provided with a skirt that
includes flexible wings, so that when the piston goes back it
forces the head to move on the external walls of the axis, so when
it arrives to the section change the fins expand against the walls
of the hole of the last.
[0048] Therefore, the last is compactly fixed during the removal of
the surpluses, allowing the maximum operation precision.
[0049] Advantageously, the drills are interchangeable.
[0050] This way, with a single drillholder different drills can be
used according to the operation of machining to be carried out.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] With the purpose of facilitating the description of what has
been described previously some drawings are attached which,
schematically and only by way of a non-limitative example, a
practical case of embodiment of the method and the machining center
of the present invention is represented, in which:
[0052] FIG. 1 is a representation of the last before being
machined;
[0053] FIG. 2 is a representation of the last after being
machined;
[0054] FIG. 3 is a view of the machining center and the last in the
first machining phase;
[0055] FIG. 4 is a detailed view of the first fastening means of
the machining center;
[0056] FIG. 5 is a detailed view of an alternative embodiment of
the first fastening means of the machining center;
[0057] FIG. 6 is a detailed view of the second fastening means of
the machining center;
[0058] FIG. 7 is a view of the machining center and the last in the
second machining phase;
[0059] FIGS. 8 and 9 are schematic representations that show the
operation of the second fastening means of the machining
center.
DESCRIPTION OF PREFERRED EMBODIMENT
[0060] In FIG. 1, it may be seen the last 1 as it leaves of the
rough-hewn process. In this process, the surface of the last 1 is
machined making rotate a piece of polyethylene about an axis
defined by two supports. These supports hold the last housed in a
pair of housings 2, 3 located in the toe and in the heel-pad,
respectively. Therefore, in the area in which there are these
housings left surpluses 4, 5 not machined which must be
eliminated.
[0061] FIG. 2 shows how the last 1 will be after passing by the
method of the present invention.
[0062] As may be seen, the last 1 already presents its definitive
shape, the surpluses 4, 5 have been eliminated, there are made a
couple of holes 6a, 6b in the upper area, a hole 6c which crosses
horizontally the instep, and other three holes 6d in the area of
the sole. On the other hand, it is also recorded the number of size
7 of the last 1 and other data on it.
[0063] The hole 6b made in the upside of the last 1 has the
function to house a spike that will hold a part of the instep 8
that will be cut, in a later phase, to facilitate the extraction of
the footwear.
[0064] The hole 6a will serve like fastening means of the last 1 in
later production phases, and also, as will be described later on,
it will serve to hold the last 1 in the process of the
invention.
[0065] The hole 6c is designed to facilitate the extraction of the
instep 8 when the last is housed in the footwear.
[0066] The holes 6d of the sole of the last 1 will be used later on
to insert some metallic head screws without exit that will allow
the introduction of a head that will pierce a plastic insole that
will fix it quickly and precisely to the sole of the last 1. This
way, it is obtained a new improvement in the whole chained process
of production of the footwear.
[0067] Hereinafter, it will be described the process that will be
carried out for machining the last 1 detailedly.
[0068] As it can be seen in FIG. 3, the last is placed in a
machining center 10 as it is shown. The center 10 is provided with
first fastening means that consist on supports 11a, 11b that hold
the last 1 by the housings 2, 3 present in the surpluses 4, 5
present in the toe and in the heel-pad, respectively. As it has
been explained previously, these housings 2, 3 had already been
used in a previous rough-hewn process, so that it is not necessary
to machine them expressly for this process. In FIG. 4 it can be
seen a detail of the supports 11a, 11b, which present protrusions
12 that will be housed in the respective housings 2, 3. This way,
the fastening of the last 1 is carried out of consistent form and
it permits the rotation without problems.
[0069] In another embodiment, shown in FIG. 5, the support 11a
presents a single cylindrical protrusion 12 that will be housed in
a complementary housing 2 present in the surplus 4 of the toe of
the last 1, so that the turn of it takes place without necessity of
rotation of the support 11a too. Although the protrusion 12 of this
embodiment is cylindrical, its shape could also be conical or
similar, so it allows the rotation of the last without any
difficulty.
[0070] The placement of the last 1 in the machining center 10 is
carried out by an operator that will regulate the position of the
supports 11a, 11b according to the measure and characteristics of
the last 1, in order to position it correctly.
[0071] For this, these supports 11a, 11b have means which permits
the vary their position. Both supports 11a, 11b can vary in angle,
and can rotate about their own axis. The support 11a, also, is
fixed to means that allow the height and in-depth regulation of it.
These means consist on a pneumatic piston 13 that will regulate the
depth, and on a endless screw 14 that by means of its turn, moves
in height the support 11a. The piston 13 and the endless screw 14
are commanded respectively by an operator by means of a joystick
and a rotatable handle (not shown).
[0072] This way, the operator can position the last 1 quickly and
effectively.
[0073] Once the last 1 is correctly positioned, the machining
process begins. A drill 15 takes charge to machine the last, making
the holes shown in FIG. 2. To access to the different points on the
surface of the last 1, the center 10 carries out the necessary
movements: the support 11b which is associated to the fourth axis
of the machining center 10 makes rotate the last 1 thanks to the
action of a motor 9, a movable bank 16 makes the horizontal
displacement of it which holds all the fastening devices of the
last 1, and the drill 15 makes the vertical movement.
[0074] This way, the drill 15 can access to the whole surface of
the last 1 and make the holes without difficulty. To machine holes
of different diameter or to carry out the identification marking of
the last, the center 10 has additional drills 17 of different size
and characteristics, using the most convenient in each case.
[0075] Once concluded this phase, the last 1 already have all the
necessary holes and the identification marking (see FIG. 2).
[0076] In the following phase, the surpluses 4, 5 of the last 1 are
eliminated.
[0077] For this, an operator removes the last of the supports 11a,
11b to fix it in second fastening means located in an arm 18 with
can turn about an horizontal axis which is, as the first support
11b of the first fastening means, associated to the fourth axis of
the center 10, as FIG. 6 shows.
[0078] These second fastening means (see FIG. 5) are constituted by
a couple of cylinders 19, 20 of different size. The fastening is
carried out introducing these cylinders 19, 20 in the holes 6b, 6a
made in the previous phase, so that the last 1 is in a vertical
position.
[0079] To retain efectively the last, the cylinder 20 is provided
with pressure means against the internal walls of the hole 6a of
the last 1, once it has been introduced in it.
[0080] The operation of these means is described in FIGS. 7 and
8.
[0081] At the moment in which the last 1 is placed in the second
fastening means, the cylinders 19 and 20 are introduced
respectively in the holes 6b and 6a.
[0082] The cylinder 20 is formed by a hollow shaft 21 whose
external walls present a widening 22. This axis 21 house in its
interior a piston 23 associated to a pneumatic cylinder 24, and
coupled at its end to a head 25 provided with a skirt formed by
flexible wings 26.
[0083] Once the last 1 have been placed, the pneumatic cylinder 24
is driven, displacing the piston 23 that in turn drags the head 25.
When the head 25 arrives to the widening 22, the wings 26 expand
and they press against the internal walls of the hole 6a of the
last 1.
[0084] The removal of the surpluses 4, 5 is carried out similarly
to the first phase, by means of the combined action of the arm 18
driven by the motor 9 (rotation movement), the movable bank 16
(horizontal movement) and the drill 15 (vertical movement).
[0085] Once eliminated the surpluses 4, 5 the last 1 already
present their practically definitive form, with all the necessary
holes for later phases gives the carried out production, properly
marked and identified, and without surpluses.
[0086] As it may be seen, the method and the machining center of
the invention present some advantages in front of the current
production systems of lasts, among the most significant, it is
necessary to highlight:
[0087] Shorter control control and calibration times, thanks to the
great precision of the machining and to the faithful reproduction
according to the designs.
[0088] Reduced waiting times between machines, thanks to the
possibility to carry out on one machine more operations, and
therefore, a greater use of the surface of the factory.
[0089] Reduction of the number of verifications between
operations.
[0090] Increase of the production flexibility in terms of easy
adaptability to the embodiment of different types which are
manufactured.
[0091] Decrease of the rejection of fabricated shapes, as
consequence of the greater precision of the machine.
[0092] It is eliminated the necessity to use a great quantity of
tools, with the consequent saving.
[0093] Possibility to carry out more economicaly pieces of
complicated geometry.
[0094] It improves of the onsite work security, when decreasing the
interactivity degree between the machine and the operator during
the machining process.
[0095] Smaller number of operators to use the machine.
[0096] Hereinafter, a comparative table is shown in which the time
has been calculated for the production of a couple of lasts as
there are carried out now and by means of the method object of the
invention.
[0097] Current Method:
1 Operation Time Current method: Rough-hewn of the lasts with 1'30"
irregular finishing Finishing of the lasts 6'55" Marking, piercing
of the last 45' and insertion of the metallic case Cutting and
polishing of the surpluses 9'20" of the heel-pad Cutting the instep
and spike threading 3' Flaming .sup. 20" TOTAL TIME 21'50" New
method: Rough-hewn of the lasts with 1'30" irregular finishing
Finishing of the lasts 6'55" Piercing, marking of the lasts 2' and
rough-hewn of the surpluses of the toe and the heel-pad Cutting the
instep, threading the 3' spike to hold the instep, Insertion of the
metallic case Flaming .sup. 20" TOTAL TIME 13'45"
[0098] The time difference between methods both it is of more than
eight minutes for each couple of lasts. So, it can be deduced that
in industrial production the productivity increase with the method
of the invention it is very significant.
* * * * *