DESCRIPTION

The present invention relates to a shoe manufacturing system as defined in the preamble of claim 1.

Shoe manufacture is known to comprise a variety of operations, such as: pre-fitting the upper to the last, fitting the toe, fitting the shoe seat, fitting the sides, riveting, roughing and gluing, applying the insole, applying the sole and/or sewing.

Once these operations were earned out manually, but in recent years specially designed machines have been made available to carry out each operation, to ensure both consistent processing quality and high throughput.

In spite of their automatic nature, these machines still require the shoe last to be positioned at a workstation, whereby an operator must be present for loading and unloading the lasts from the machines, and conveyor means must be provided for the semifinished shoes to be conveyed from one machine to another, as there is no single machine that can carry out all the required operations.

It shall be further noted that prior art machines have been designed to carry out many of the aforementioned operations (e.g. fitting the sides and the shoe seat or roughing and gluing before applying the insole), with the shoe last oriented with the last sole facing upwards.

This is partially required because the glue should be delivered from top to bottom to avoid undesired dripping. Such upturned position of the shoe last (with the sole facing upwards) is also required to allow the operator to check that the operations are being carried out properly and to possibly take manual actions to complete certain operations. In response to the aforementioned requirements, the shoe manufacturing industry has developed highly improved automatic machines that can carry out the various operations in a full standalone mode, but still require the presence of an operator for the last to be handled from one workstation to another.

Therefore, the need is strongly felt for the possibility of automatically handling shoe lasts, the upper and the other parts required to form a shoe from one machine to another. In an attempt to meet this need, the use of manipulators has been suggested, such manipulators having grippers that can grasp the shoe lasts at a special grip extension projecting out of the shoe last portion corresponding to the neck. This is because such grippers are adapted to only grasp items with constant and preset shapes, and cannot grasp a conventional shoe last, whose size and shape change according to its model, unless it has. such grip extension.

This limitation has hindered success of this type of arrangement, as the use of such manipulators with grippers requires replacement of all existing conventional shoe lasts with new, specially designed shoe lasts having such grip extension.

Furthermore, it should be noted that, since the shoe lasts must be handled by grasping them at the aforementioned grip extension that projects out of the portions defining the neck of the shoe last, such shoe lasts cannot be used with existing machines, as the latter require the shoe last to be handled and positioned with the sole facing upwards. It will be appreciated that this condition might be only fulfilled by obviating the problem of gripping the shoe last at its sides, which may have a highly variable bulging or concave profile depending on the model of shoe to be formed, and on the shoe size.

Therefore, the present invention is based on the problem of conceiving a shoe manufacturing system, that:

- comprises a plurality of automatic or semiautomatic machines for carrying out the required shoe manufacturing operations; - exhibits such structural and functional features as to meet the aforementioned need to automatically handle conventional shoe lasts from one machine to another by holding them at their sides and/or to grip and handle shoe parts; and

- can also obviate the above discussed prior art drawbacks.

This problem is solved by a shoe manufacturing system as defined in claim 1.

In another aspect, the problem is also solved by the use of an adaptive gripping manipulator as defined in claim 23.

Further features and advantages of the shoe manufacturing system of the present invention, will be apparent from the following description of one preferred embodiment thereof, which is given by way of illustration and without limitation with reference to the accompanying figures, in which:

- Figure A shows a schematic view of one embodiment of the shoe manufacturing system of the present invention;

- Figure 1 shows a perspective view of an adaptive gripping manipulator of the invention, in an open configuration, which is carried at the free end of an arm of a robot;

- Figure 2 shows a lateral plan view of the manipulator of Figure 1 ;

- Figure 3 shows a front plan view of the manipulator of Figure 1;

- Figures 4a and 4b show two different perspective views of the gripping manipulator of Figure 1 in a closed gripping configuration;

- Figure 5 shows a lateral plan view of the manipulator of Figures 4a and 4b;

- Figure 6 shows a front plan view of the manipulator of Figures 4a and 4b;

- Figure 7 shows a perspective view of a finger gripper of the manipulator of the invention,

- Figures 8, 9 and 10 show perspective views of the manipulator 1 as it grips a shoe last or a shoe sole and - Figure 11 shows a schematic view of a possible architecture of a shoe manufacturing system of the invention.

Referring to Figure 1, a shoe manufacturing system of the invention is generally referenced 100.

The shoe manufacturing system 100 comprises:

- at least one warehouse containing shoe parts or components, shoe lasts and/or semi-finished or finished shoes;

- a plurality of shoe lasts 4 which are designed to receive shoe parts during shoe manufacturing operations and

- a first work cell 101 comprising a first plurality of automatic or semiautomatic machines Mi, M ₂ , ... Mj for carrying out one or more of the required shoe manufacturing operations.

Advantageously, the shoe manufacturing system comprises a first robot R having an articulated arm 15 having a gripping manipulator 1, said first robot R being in such a position as to be able to operate on said first machines Mi, M ₂ , ... Mi of said first plurality of automatic or semiautomatic machines Mi, M ₂ , ... Mj and/or on said warehouse to:

- selectively grip said shoe lasts 4 at the sides of said shoe lasts 4 using said gripping manipulator 1 , and handle said shoe lasts 4 in a predetermined manner among said first machines Mi, M ₂ , ... Mj and/or said at least one warehouse and/or

- selectively grip said shoe parts 13 using said gripping manipulator 1 and handle them in a predetermined manner between said at least one warehouse and said first machines Mi, M ₂ , ... Mi.

It shall be noted that, as used in the description and the claims, the term selectively grip the shoe lasts 4 at their respective sides using the gripping manipulator 1 is intended to be related both to the case in which the shoe last has no upper thereon and to a processing condition in which an upper has already been placed on the shoe last. In the latter case, the gripping manipulator 1 will obviously grip the shoe last at its sides with the interposition of the upper, i.e. with the gripper not directly contacting the shoe last. Preferably, said first work cell 101 comprises local processing, management and control means LI for managing and controlling:

- the operation of said first robot R;

- the operation of said first machines Mi, M _2j .. . Mi of said first plurality of automatic or semiautomatic machines M _1} M _2, . . . M, and

- the handling of said shoe lasts 4 and said shoe parts 13 in said first work cell

101 ,

for supervision of the processing steps to be carried out in said first work cell 101 for each particular shoe being manufactured.

Preferably, the shoe manufacturing system 100 comprises at least one buffer B for temporary accumulation of the shoe lasts 4 and the shoe parts already applied to or associated with said shoe lasts 4, said at least one temporary accumulation buffer B being served for loading and/or unloading by the gripping manipulator 1 of the first robot R.

Preferably, this buffer B is a thermal conditioning buffer, preferably for heating or cooling and/or having hygroscopic properties for changing the moisture content in the shoe parts. By this arrangement, the shoe parts may undergo heating, cooling and/or change of moisture content prior to the manufacturing process, during the manufacturing process or at the end of the manufacturing process as needed.

Preferably, the aforementioned shoe manufacturing system 100 comprises at least one additional second work cell 102 comprising: - a second plurality of automatic or semiautomatic machines ΜΊ, M' _2; ... M'j for carrying out one or more of the required shoe manufacturing operations;

- possibly a warehouse for containing shoe parts or components, shoe lasts and/or semi-finished or finished shoes;

- a second robot R' comprising an articulated arm 15 having a gripping manipulator 1, which is in such a position as to be able to operate on said machines ΜΊ, Μ' _2> ... M'j of said second plurality of automatic or semiautomatic machines M'i, M' _2i . .. M'j or on said warehouse, if any, to:

- selectively grip said shoe lasts 4 at the sides thereof and handle them in a predetermined manner among said machines ΜΊ, M' _2> ... M'i and/or said warehouse, if any, and/or

- selectively grip said shoe parts 13 and handle them in a predetermined manner between said at least one warehouse and said machines ΜΊ, M' _2; ... M'i .

Preferably, the aforementioned at least one first work cell 102 comprises local processing, management and control means LI 'for managing and controlling:

- the operation of said second robot R' ;

- the operation of said machines ΜΊ, M' ₂ , ... M'i of said second plurality of automatic or semiautomatic machines M' _1} M' _2j ... M'i and

- the handling of said shoe lasts 4 and said shoe parts 13 in said second work cell 102,

for supervision of the processing steps to be carried out in the second work cell 102 for each particular shoe being manufactured.

Preferably, the first cell 101 and the at least one second cell 102 are interconnected for exchanging shoe lasts 4 and shoe parts associated therewith through a temporary accumulation buffer B which is served for loading and/or unloading by the gripping manipulator 1 of said first robot R and by the gripping manipulator 1 of said second robot R', preferably a thermal conditioning and/or hygroscopic buffer B, for changing the moisture content in the shoe parts.

Preferably the shoe manufacturing system 100 comprises:

- trackable ID tags, preferably RFID tags, associated with said shoe lasts 4 and/or said shoe parts and

- means for reading said trackable ID tags, associated with said manipulators 1 and/or said first machines ΜΊ, ΜΊ _, ... M'j and said second machines ΜΊ, M'2, ... M

Preferably, the shoe manufacturing system 100 comprises a central processing unit management and control for managing, controlling and supervising:

- the operation of said work cells;

- the operation of said buffer B and/or

- the intercorrelation between said work cells.

A shoe manufacturing system has been described hereinbefore, which comprises a single work cell 101 or two work cells 101 and 102 respectively. Nevertheless, it shall be appreciated that the at least one work cell may comprise two, three or more work cells connected together in pairs or multiple cells, using respective buffers. According to the particular manufacturing requirements, these work cells may carry out either different processing operations or the same operations in parallel.

It will be also appreciated that the automatic or semiautomatic machines as used in these work cells may be well-known and available machines, i.e. the seat-fitting machines and the roughing- gluing machine of the applicant hereof.

As mentioned above, these machines are highly efficient and can perform the various processing operations autonomously, although in the prior art they still required the presence of an operator for loading and unloading the shoe lasts with the shoe parts applied thereto or associated therewith at each processing cycle in the workstation. Conversely, the use of a robot having a gripping manipulator (as further described below), allows the workstations of each of said automatic or semiautomatic machines to be loaded and unloaded without requiring the presence of an operator.

This is possible because the aforementioned manipulator 1 can selectively grip the shoe lasts 4 at their respective sides, and lay them in the workstations of each machine even with the sole facing upwards.

Figures 1 to 10 show the structure of the adaptive gripping manipulator 1 in various configurations of use, this manipulator being adapted to grip a shoe last 4 (see Figure 8) of conventional type or another part of the shoe, such as a shoe sole 13, as shown in Figures 9 and 10.

The adaptive gripping manipulator 1 comprises a body 2 which is designed to be operably connected and actuated by a robotic arm 14 of a robot.

Preferably, the gripping manipulator 1 is connected at the free end of the arm 14 by the interposition of a force sensor 12 that can determine the forces acting and/or applied by said gripping manipulator 1.

According to the illustrated embodiment, the body 2 substantially has the shape of a parallelepiped with a rectangular base extending in a longitudinal direction, with two opposed long longitudinal sides and two short transverse sides.

The shape of the body of the gripping manipulator 1 may also obviously differ from the rectangular-base shape as shown by way of example.

The aforementioned body 2 of the gripping manipulator 1 comprises a first side 3 with an outer surface that, when the manipulator grips a shoe last 4 or another object 13, faces, i.e. is turned toward such shoe last 4 or the other object 13.

The gripping manipulator 1 further comprises: - gripper means associated with the aforementioned body 2 for selectively gripping a portion of a shoe last 4 or another object 13 and

- drive means for driving such gripper means to close and open.

Advantageously:

- the aforementioned gripper means comprise at least one pair of counteracting fmger grippers 5;

- said finger grippers 5 project out of the body 2, such that a distal end 6 thereof extends beyond the aforementioned outer surface of the first side 3 of the body 2;

- each fmger gripper 5 extends along an axis n-n from an end 7 proximal to said body to said distal end 6;

- each fmger gripper 5 is articulated to move from an open configuration (see Figures 1 , 2 and 3), in which the opposed counteracting finger grippers 5 of each pair of finger grippers 5 are in spaced relationship, to a closed configuration (see Figures 4a, 4b, 5, 6, 8, 9, 10) in which the aforementioned distal ends 6 of the opposed counteracting finger grippers 5 of each pair of finger grippers 5 become:

- closer to the aforementioned outer surface of said first side 3 of said body 2 and

- closer to or in contact with each other

as compared with the position assumed by the fmger grippers 5 when the gripping manipulator 1 is in the aforementioned open configuration.

Preferably, as the opposed finger grippers of each pair of fmger grippers move from the open configuration to the aforementioned closed configuration, they assume a more curved shape, with the concavity facing the opposed fmger gripper 5 of each pair of finger grippers 5, as shown for instance in Figure 6.

Preferably, the adaptive finger grippers 5 are articulated about articulation axis Y-Y extending parallel to a direction:

- perpendicular to the axis n-n of each fmger gripper 5 and

- perpendicular to the ideal plane extending through two counteracting finger grippers of the same pair of fmger grippers 5.

More preferably, each finger gripper 5 comprises a plurality of segments 8a, 8b, 8c which extend in mutual end-to-end articulatingly connected relationship from the aforementioned proximal end 7 to the aforementioned distal end 6.

Each fmger gripper 5 is found to have an inner side, which faces/is turned toward the aforementioned outer surface of the first side 3 of the body 2, and an outer side opposite thereto;

According to the illustrated embodiment (as shown for instance in Figures 6 and 7):

- each fmger gripper 5 comprises an end segment 8a which defines said distal end

6;

- the inner side of each finger gripper 5 comprises a first plurality of said segments 8b which axially extend in mutual end-to-end articulatingly connected relationship between said end segment 8a until they define an inner portion 7a of the proximal end 7;

- the outer side of each fmger gripper 5 is defined by a second plurality of said segments 8c which axially extend in mutual end-to-end articulatingly connected relationship from an outer portion of said end segment 8a until they define an outer portion 7a of said proximal end 7;

- the inner portion 7a of the proximal end 7 of each fmger gripper 5 is hinge- connected to a respective point 15 of said body 2, to rotate about a respective axis of articulation Y-Y, parallel to the longitudinal axis of the body 2;

- the outer portion 7b of the proximal end 7 of each finger gripper 5 is rotatably driven by the aforementioned drive means. Preferably, the drive means for the gripping manipulator 1 comprise, for each finger gripper 5, respective electric motor having a rotating shaft 9 connected via a respective lever/crank 10 to the outer portion of said proximal end 7 of each finger gripper 5.

Alternatively, a single motor may be provided to move more than a finger gripper 5 or to move all the gripping fingers of the gripping manipulator 1. Here, the mechanical transmission provided for transferring motion from the motor to the finger grippers 5 should include limiter means for limiting the maximum transmitted clamping force/torque, for each finger gripper, such as torque limiters, clutches and the like.

Preferably, in each finger gripper 5 of the gripping manipulator 1, the corresponding articulating points of said first plurality of segments 8b and of said second plurality of said segments 8c are articulatingly connected via respective connecting rods 11.

The aforementioned connecting rods 11 and segments 8 define four-bar linkages in the structure of each finger gripper 5.

Preferably, in each finger gripper 5, the respective outer articulated side converges toward the inner articulated side, from the proximal end 7 to the distal end 6.

Preferably, the gripping manipulator 1 comprises resilient material and/or elastic means 16 located between the aforementioned first plurality of segments 8b of the inner side andithe aforementioned second plurality of segments 8c of the outer side of each finger gripper 5.

Preferably, each finger gripper 5 of the gripping manipulator 1 comprises at least two articulation points along its own axis n-n and preferably comprises at least three articulation points.

As shown in the figures, the axis n-n of each finger gripper 5 of the gripping manipulator 1 assumes a substantially straight shape when the manipulator is in the open configuration (see Figure 3), and it has the shape of a broken line when the manipulator 1 is in the closed configuration (see Figure 6).

Preferably, the gripping manipulator 1 comprises two pairs of mutually staggered opposed fmger grippers 5.

According to the illustrated embodiment, the two pairs of opposed fmger grippers 5 are mutually staggered in the longitudinal direction X-X, i.e. along the long sides of the body 2.

The two pairs of opposed finger grippers allow the gripping manipulator 1 to grip the shoe last 4, or another object 13, at two spaced-apart points, thereby ensuring a firm and stable grasp thereon.

Preferably, each fmger gripper 5 comprises a gripping portion, coated with or formed with a high friction coefficient material at said distal end 6.

Preferably, each fmger gripper 5 comprises a gripping portion with a roughened surface at said distal end 6.

Preferably, the gripping manipulator comprises, for each finger gripper 5, respective sensor means for determining directly or by indirect measurement the closing force exerted by each finger gripper 5.

The method of manufacturing shoes using shoe lasts 4 includes the steps of:

- providing a shoe manufacturing system 100 as described above,

- handling the shoe parts in said first work cell 101 using said first robot R;

- handling the shoe lasts 4 in said first work cell 101 by means of said first robot 4 by selectively gripping said shoe lasts 4 at their sides using said gripping manipulator 1 and

- using the first machines Mi, M _2; ... Mj to carry out processing steps on the shoe parts associated with the shoe lasts, and located at each of said first machines Mi, M _2; ... Mi. Preferably, if the aforementioned shoe manufacturing system 100 also comprises the second work cell 102, then the method of manufacturing shoes comprises the step of using the aforementioned temporary accumulation buffer B to handle the shoe parts and/or the shoe lasts between the first work cell 101 and the second work cell 102. Preferably the method of manufacturing shoes comprises the steps of:

- storing, for each different type of shoe, the required shoe components, the shoe last to be used for application of said shoe components, and the sequence of processing operations to be carried out in the various machines;

- identifying each shoe last being handled and

- according to the shoe last so identified, applying/associating the required shoe components and carrying out the processing operations in each machine following the sequence as provided in the stored data.

As clearly shown in the above description, the shoe manufacturing system of the present invention fulfills the above mentioned need and also obviates prior art drawbacks as set out in the introduction of this disclosure. The structure of the aforementioned manipulator allows such manipulator to grip objects such as a shoe last of conventional type, i.e. is a shoe last like those that are manually handled by an operator in the usual shoe manufacturing processes.

It shall be noted in this respect that the shoe lasts have different shapes and sizes according to the size and special shape of the shoe to be manufactured. Furthermore, these shoe lasts have rather rounded and curved shapes that are not easily grasped by a gripper having straight tines, that can only perform a normal opening and closing movement. However, the gripping manipulator of the invention is found to be of adaptive type, as it can be adapted to and conformed with the shape of the shoe last to be picked up, and can thus fit its round, bulged or concave shapes to ensure a firm and effective grip.

This result is achieved because the opposed finger grippers of each pair of finger grippers cooperate by gripping together, possibly not in the same manner from one finger gripper to another, on the shoe last to be grasped. As mentioned above, as the gripping fingers move from the open configuration to the closed configuration they take a position that is closer to the body of the manipulator, preferably assuming a more curved profile, that can ensure a firm grip on the shoe last by form fit.

Preferably, such adaptive gripping effect is ensured because the finger grippers are articulated and comprise, for instance, the aforementioned plurality of segments extending in mutual end-to-end articulatingly connected relationship.

One advantage that can be achieved by using the gripping manipulator consists in the possibility to directly or indirectly determine and adjust, for each finger gripper, both the shape to be assumed and also the maximum pressing force to be applied to the object to be gripped and picked up, thereby increasing the ability of the gripping manipulator to adapt to the particular shape of the shoe last to be picked up.

One more advantage of the gripping manipulator consists in the possibility of using such manipulator to: automatically handle the shoe lasts and automatically handle the shoe parts. Such manipulator is also able to load and unload the shoe lasts not only to and from the warehouses, but also an especially the known machines that are typically used for:

- fitting the upper to the last,

- fitting the toe,

- fitting the shoe seat,

- roughing,

- gluing, - fitting the insole,

- etc.

considering that, before the present invention, while the aforementioned known machines had an automated operation, they still required the presence of an operator to manually load and unload the shoe lasts and the shoe parts that have been applied.

An advantage that results from the use of the shoe manufacturing system of the invention consists in the possibility of an almost entirely automatic shoe manufacturing process, due to the use of one or more manipulating robots, and of reducing labor using the technology of existing automatic or semiautomatic machines, which can be integrated in the shoe manufacturing system of the invention not only from the structural and functional point of view, but also in terms of integration with the general control and management system and/or that of the individual work cell.

Those skilled in the art will obviously appreciate that a number of changes and variants may be made to the above described gripping manipulator, still within the scope of the invention, as defined in the following claims.

Thus, for example, more than one robot may be provided within a single work cell.