A machine for fitting a footwear upper onto a last

Abstract: A machine (1) for fitting a footwear upper (2) onto a last (3) comprises a load-bearing structure (4, 5) which has a support for positioning a last on which an upper is supported, and a tensioning gripper (15) for engaging and pulling the edge of the upper (2) . Advantageously, the machine (1) comprises means (8) for engaging the last and clamping it to the support (7) and the gripper (15) is positioned in the region of the front portion of the last (3) and is movable between a forward position in which it is close to the front portion of the last so as to be able to grip the front end of the upper, and a position to which it is withdrawn away from the last and in which the upper is fitted onto and stretched well over the last.

Description: The present invention relates to a machine for fitting a footwear upper onto a last, comprising means for positioning a last on which an upper is supported, and a tensioning gripper for engaging and pulling the edge of the upper. As is known, during the manufacture of footwear, the upper has to be fitted onto the last before operations such as the gluing or sewing of the inner soles or of the sole are performed by pre-assembly machines. Generally, when the upper is of limited thickness and is therefore not very heavy it suffices to fit the upper on the last by hand before inserting the last in the pre-assembly machine. For heavier uppers such as, for example, those used in mountaineering or alpine climbing boots, on the other hand, the fitting of the upper on the last is very hard work and requires a large fitting force. It should also be pointed out that, in this case, the last with the upper fitted thereon cannot be inserted in the pre-assembly machines until the upper has been pulled onto and stretched well over the last, and the laces of the upper have been fastened. At the moment, the fitting of heavy uppers onto the last is performed predominantly by hand by skilled operators and requires a large physical force, in spite of the use of tools such as hammers and the like. It is clear from the foregoing that there is a great need, in the footwear field, to be able to fit the upper, particularly a heavy upper in the sense defined above, onto the last quickly and easily and without the need for a large physical force. A further need to be taken into consideration is that of fitting the upper onto a last with the interposition of a layer of waterproof material such as, for example, Gore-Tex®. The Gore-Tex® material is generally in the form of a bag in which the last is inserted before the upper is fitted. Naturally, in order for the material to provide the necessary waterproofing, the opening of the bag of waterproof material must be positioned in the region of the ankle of the last. To avoid the need to fit the upper onto the last manually, it has been proposed to use pre-assembly machines, after appropriately removing therefrom elements such as lateral clamps, upper stretchers and pads for contacting the upper to ensure the positioning and the clamping of the last. However, the use of a pre-assembly machine to fit the upper on the last is unsatisfactory for various reasons. First of all, it is necessary to ensure manually that the last is positioned correctly on the positioning means of the machine and, in particular, to keep the last stationary during the fitting of the upper. The pads which are normally provided in these machines for keeping the last in position cannot in fact be used because they would interfere with the upper. Moreover, it must be borne in mind that the solution of partially dismantling a complex and expensive machine such as a pre-assembling machine in order to fit the upper on the last in a manner which is not even very satisfactory is very economically disadvantageous. German Patent DE-A-1 510 003 discloses a machine for fitting a footwear upper onto a last having a load-bearing structure for a tensioning gripper, means for positioning a last, one tensioning gripper positioned in the front portion of the last and a plurality of tensioning grippers positioned along the side and rear portion of the last. Patent US-A-3 906 568 discloses a lasting machine having toe tensioning grippers, side tensioning grippers and a shoe support. The problem upon which the present invention is based is that of devising a machine for footwear manufacture which has structural and functional characteristics such as to satisfy the above-mentioned need and at the same time to prevent the problems referred to. This problem is solved by a machine for fitting a footwear upper onto a last according to Claim 1. Further characteristics and the advantages of the machine according to the present invention will become clear from the following description of a preferred embodiment thereof, given by way of non-limiting example, with reference to the appended drawings, in which: Figure 1 is a schematic, perspective view of a machine according to the invention for fitting a footwear upper onto a last, and Figures 2 to 5 are schematic plan views of a detail of the machine of Figure 1 during 4 different stages of its operating cycle. With reference to the appended drawings, a machine according to the invention for fitting a footwear upper 2 onto a last 3 is generally indicated 1. In wholly conventional manner, the last 3 extends along a predetermined longitudinal axis between a front portion and a rear portion of the last and comprises a sole 3a, sides and an upper portion. The upper portion of the last 3 has a front upper portion 3c shaped like the instep of a foot and adjoining a substantially flat and horizontal remaining, rear upper portion 3b. This rear upper portion 3b of the last 3 corresponds to the ankle opening of the upper 2. The machine 1 comprises a support base 4 from which a pillar 5 formed by a tubular metal element of square cross-section extends vertically. The pillar 5 is preferably in the form of two tubular elements of square cross-section which are coaxial and are fitted slidably one inside the other so as to form a coupling between complementary channelled profiles. Conventional clamping means, in the specific case, a screw clamp 6, enable the sliding of one tubular element relative to the other to be locked, so that the height of the pillar 5 relative to the support base 4 can be adjusted. The support base 4 and the pillar 5 form the load-bearing structure of the machine 1. The machine 1 has means for positioning the last 3. These means comprise a support 7 which defines a surface for supporting the sole 3a of the last 3, and means 8 for engaging the last 3 and clamping it relative to the load-bearing structure of the machine 1, at the same time avoiding interference with the upper 2. In the embodiment shown, the support 7 is in the form of a tubular element of predetermined axis X-X projecting from the upper end of the pillar 5. As can be seen from the drawings, the support 7 is inclined in a manner such that the perpendicular axis Z-Z to its support surface substantially coincides with the line of sight of an operator looking at this surface and standing in front of the machine 1 (at the point indicated 0 in Figure 1). The support 7 thus supports the last 3 from below so that the upper 2 supported thereon faces upwards. The support 7 comprises a triangular flat surface, indicated 22 in the drawing, on which the front portion of the sole 3a of the last 3 bears. The support 7, in the same manner as the pillar 5, is also in the form of two tubular elements of square cross-section which are coaxial and are fitted slidably one inside the other so as to form a coupling between complementary channelled profiles. Conventional clamping means, in the specific case, a screw clamp 9, enable the sliding of one tubular element relative to the other to be locked, so that the length of the support 7 can be adjusted to adapt it to the length of the last 3. The means 8 for engaging the last 3 and clamping it relative to the load-bearing structure of the machine 1 comprise a head 10 having an end which can be engaged in a corresponding recess 11 suitably provided in the last 3 so as to achieve a male/female shaped coupling between complementary profiles. In the embodiment shown in the drawings, the above-mentioned end of the head 10 is in the form of a cylindrical pin of circular cross-section, and the recess 11 is in the form of a blind hole of circular cross-section. The head 10 is advantageously disposed above the portion of the support 7 on which the upper rear portion 3b of the last 3 is positioned. The above-mentioned means 8 for engaging the last 3 and clamping it relative to the load-bearing structure of the machine 1 consequently act on the upper rear portion 3b of the last 3, extending through the ankle opening of the upper 2 so as not to interfere with the upper 2. In this connection, it should be pointed out that, in footwear lasts, a circular hole is generally formed in the upper rear portion 3b. The machine 1 thus enables the upper to be fitted on conventional lasts. In the embodiment described, the head 10 is supported by an L-shaped arm 12 of tubular, square cross-section. The arm 12 comprises a first portion 12a which extends parallel to the axis Z-Z from the free end of the support 7, and a second portion 12b which extends substantially parallel to and above the support 7. The head 10 is connected to the free end of the second portion 12b. The first portion 12a of the arm 12 is preferably connected to the free end of the support 7 by means of a sleeve 14 having a square cross-section and oriented parallel to the axis Z-Z. More precisely, the first portion 12a of the arm 12 is fitted coaxially and slidably in the sleeve 14. Conventional clamping means, in the specific case, a screw clamp 13, enable the sliding of the arm 12 relative to the sleeve 14 to be locked. The distance of the second arm 12 and of the head 10 from the underlying support 7 can thus be adjusted. The head 10 is connected to the second portion 12b of the arm 12 by an articulated connection so as to be movable between an operative position (Figures 1, 3-6), in which the head is oriented parallel to the axis Z-Z with the above-mentioned end facing towards the support 7, and a starting position (Figure 2), to which the head 10 is pivoted so as to be substantially parallel to the support 7. The pivoting of the head 10 from the starting position to the rest position is brought about by conventional actuator means (not shown in the drawings), for example, pneumatic actuator means. If a more simplified, manual machine is to be produced, the head 10 can be pivoted between the two above-mentioned positions by being moved manually. In this case, it is useful to provide a clamp which enables the head to be locked in the desired angular position relative to the arm. The machine 1 also comprises a tensioning gripper 15 for engaging and pulling the edge of the upper 2 supported on the last 3. Advantageously, the gripper 15 is positioned in the region of the front portion of the last 3 and is movable between a forward position (Figures 3 and 4) in which it is close to the front portion of the last 3 so as to be able to grip the front end of the upper 2 and a withdrawn position (Figure 5) in which it exerts a pulling action on the upper 2 so as to fit the upper 2 onto the last 3. The movement of the gripper 15 from the forward position to the withdrawn position takes place by a movement of the gripper comprising a displacement component (indicated by the arrow A in Figure 5) substantially parallel to the axis X-X of the support 7, that is, along the longitudinal axis L-L of the last 3. This displacement component enables the upper 2 to be fitted onto the last 3. The movement of the gripper 15 from the forward position to the withdrawn position also comprises a vertical, downward displacement component (indicated by the arrow B in Figure 5) substantially perpendicular to the axis X-X. During the movement from the forward position to the withdrawn position, the gripper 15 preferably describes an arc of a circle. In the embodiment shown, the gripper 15 is mounted on the upper end of a support rod 16 which is articulated to a fork 18 projecting from the pillar 5, so as to be pivotable relative to the pillar whilst remaining coplanar with the support 7 and the arm 12. The inclination of the support rod 16 to the vertical pillar, and consequently the distance of the gripper from the support 7 along the axis X-X, are adjusted by a conventional cylinder and piston unit 20 which connects the lower end of the support rod 16 to the pillar 5. The support rod 16 comprises an upper tubular element and a lower tubular element which have square cross-sections. The upper and lower tubular elements are coaxial and are fitted slidably one inside the other so as to form a coupling between complementary channelled profiles. The two above-mentioned tubular elements are connected, respectively, to a cylinder and to a piston of a pneumatic cylinder-piston unit 19, the operation of which enables the axial position of the upper tubular element relative to the lower tubular element to be adjusted so that it is possible to adjust the height of the gripper 15 relative to the support 7. The jaws of the gripper 15 are opened and closed by a pneumatic actuator 21 fixed to the upper tubular element of the support rod 16. The machine 1 also comprises known drive means and operating and control devices which are not shown in the drawings but are necessary to ensure its correct operation. In particular, during each operating cycle of the machine 1, the operating and control means enable the gripper 15 and the head 10 to be positioned and moved in the correct sequence described below. In order to adapt to different uppers and lasts, the operating and control means comprise a memory, such as, for example, an EEPROM, in which various programs of movement can be stored. The operation of the machine 1 will now be described below, starting from an initial operating condition in which the head 10 is in the starting position (Figure 2) and the upper 2 is supported on the last 3. The last 3 bears against the head 10, as shown in Figure 2, so that the end of the head 10 is engaged in the recess 11 in the upper rear portion 3b of the last 3. The head 10 is then pivoted from the rest position to the operative position (Figure 3) so as to bring the last 3 to a position in which it bears on the support 7 and, in particular, on the flat triangular surface 22. At the same time, the gripper 15 is positioned in a manner such that the front end of the upper 2 is inserted between the open jaws of the gripper. In the subsequent steps, the pneumatic actuator 21 closes the jaws of the gripper 15 which are clamped onto the end of the upper 2 (Figure 4). At this point, the pneumatic cylinder-piston unit 19 and the cylinder-piston unit 20 act on the support rod 16 in a manner such that the gripper 15 moves from the forward position to the withdrawn position, describing an arc of a circle, as described above. This movement of the gripper enables the upper 2 to be fitted onto the last 3 easily and quickly without the operator having to exert large physical forces, even for heavy uppers such as those used in mountaineering or alpine climbing boots. It should be stressed that the movement of the gripper 15 enables the upper 2 to be fitted onto the last 3 by virtue of the fact that the last is clamped against the support 7 by the head 10 without the upper 2 being affected. In other words, the upper 2 is free to move relative to the last. When the gripper 15 is in the withdrawn position (Figure 5), the upper 2 is fitted onto the last and stretched well over it, and the laces can be fastened. When the jaws of the gripper 15 are opened and the head 10 is returned to the rest position (Figure 2), the last can be removed from the machine with the upper 2 fitted onto and well stretched over the last. The machine 1 can also be used for fitting the upper onto a last which has previously been inserted in a bag of waterproof material such as Gore-Tex®. As can be appreciated from the description, the machine for fitting a footwear upper onto a last according to the invention satisfies the above-mentioned need and at the same time overcomes the problems referred to in the introductory part of the present description. In fact, the machine according to the invention enables the upper to be fitted onto the last quickly and easily without the operator having to exert large physical forces, even for heavy uppers such as those used in mountaineering or alpine climbing boots. A further advantage of the machine according to the invention lies in the fact that its operation can be fully automated. A further advantage of the machine according to the invention lies in its structural simplicity, favouring reliability in operation and a low production cost. Naturally, in order to satisfy contingent and specific requirements, an expert in the art may apply to the above-described machine for fitting a footwear upper onto a last, many modifications and variations all of which, however, are included within the scope of protection of the invention as defined by the following claims. Thus, for example, the machine 1 may be modified in a manner such that the movement of the head away from and towards the operative position for engaging and clamping the last takes place with a linear movement of the head away from and towards the underlying support 7 instead of by pivoting. This movement may be brought about manually or, for example, by the provision of pneumatic actuators. The means for engaging and clamping the last may comprise an arm associated with a head for releasably engaging a corresponding end of the last. In a further variant, the head may have a chuck for engaging a shank of the last. According to yet a further variant, the means for engaging and clamping the last may comprise an expansion head which can be engaged in a recess of the last. If the head of the means for engaging and clamping the last is an expansion head, an engagement head, or another system which can achieve a firm connection between the head the last, the presence of the support having the function of a support surface for the last may be eliminated. In fact, in this case, the expansion, engagement or other equivalent system may itself be able to clamp the last during the fitting of the upper. It is also possible to position the means for engaging and clamping the last in a manner such that they act on the last from below, that is, in the region of the sole, although this solution is not suitable for the production of footwear with a layer of waterproof Gore-Tex® or other equivalent material. In this configuration, the means for engaging and clamping the last may themselves constitute the support on which the last is positioned. The gripper 15 of the machine 1 may be replaced by two or more grippers positioned so as to follow the outline of the front portion of the last 3.

Claims: A machine (1) for fitting a footwear upper (2) onto a last (3), comprising: a load-bearing structure (4, 5) comprising means for positioning a last (3) on which an upper (2) is supported so as to have the outer surface of the upper (2) faced upward in an operative position during which the edge of the upper is pulled, the last (3) extending along a longitudinal axis (L-L) between a front portion and a rear portion of the last, and at least one tensioning gripper (15) for engaging and pulling the edge of the upper (2), the means for positioning the last (3) comprising means (8) for engaging the last (3) and clamping it relative to the load-bearing structure (4, 5), and the at least one gripper (15) being positioned in the region of the front portion of the last (3), the at least one gripper (15) being movable between a forward position in which it is close to the front portion of the last (3) so as to be able to grip the front end of the upper (2), and a position to which it is withdrawn away from the last (3), characterised in that the means (8) for engaging and clamping the last (3) engage the rear upper portion (3b) of the last (3), extending through the ankle opening of the upper (2). A machine (1) according to Claim 1, in which the at least one gripper (15) moves from the forward position to the withdrawn position with a movement having a displacement component (A) substantially parallel to the longitudinal axis of the last (3) positioned on the machine (1). A machine (1) according to Claim 2, in which the at least one gripper (15) moves from the forward position to the withdrawn position by a movement having a vertical displacement component (B) substantially perpendicular to the longitudinal axis of the last (3) positioned on the machine (1). A machine (1) according to Claim 1, in which the means for positioning a last (3) comprise a support (7) defining a surface (22) for supporting the sole (3a) of the last (3), the last (3) being supported from beneath so as to have the outer surface of the upper (2) facing upwards. A machine (1) according to Claim 1, in which the means (8) for engaging and clamping the last (3) comprise an arm (12) having a head (10) which can be engaged in a corresponding recess (11) in the last (3), achieving a male/female shaped coupling between complementary profiles. A machine (1) according to Claim 1, in which the means (8) for engaging and clamping the last (3) comprise an arm (12) having an expansion head (10) which can be engaged in a corresponding recess in the last (3). A machine (1) according to Claim 1, in which the means (8) for engaging and clamping the last (3) comprise an arm (12) having a head (10) which can be releasably coupled with a corresponding end of the last (3). A machine (1) according to any one of Claims 5, 6 and 7, in which the head (10) is movable relative to the arm (12) between the operative position and a starting position, in which the last (3) is clamped relative to the machine (1) and is released therefrom, respectively. A machine (1) according to Claim 8, in which the movement of the head (10) between the operative position and the rest position is a rotary movement.

Inventors: BIANCHI CARLO, MOLINA GIUSEPPE, BIANCHI, CARLO, MOLINA, GIUSEPPE
Applicants: OHG MOLINA & BIANCHI S P A, OFFICINE MECCANICHE MOLINA & BIANCHI S.P.A.
Application year: 1999
Main classification: A43D13
IPC codes: A43D13