PULLING OVER AND LASTING TOE AND FOREPART PORTIONS OF SHOES

Abstract: For accomodating shoes of a given style but of different sizes, especially shoes having a significant bottom curvature, the operative position of the last support (10) can be varied according to the size of the shoe as well as according to style. To this end, a "style" heightwise setting of the last support (10) is modified by a subsequent "size" setting, which is carried out in response to the measurement of the last length when the heel rest (26) is moved into engagement with the back seam region thereof. To facilitate these two settings, preferably a double-cylinder arrangement (66, 68, 68a; 76, 78) is provided for effecting heightwise movement of the last support (10). The setting of the last support (10) is especially suited for electronic control, using n.c. motors for varying the position of the various stop members (72, 80, 90).

Description: PULLING OVER AND LASTING TOE AND FOREPART PORTIONS OF SHOES BACKGROUND OF THE INVENTION This invention is concerned with a method of pulling over and lasting toe and forepart portions of shoes and also with a pulling over and lasting machine for carrying out such a method. Conventionally in pulling over and lasting toe and forepart portions of shoes, a shoe, comprising an upper on a last and an insole on the last bottom, is placed on a last support and lasting marginal portions of the shoe upper in the toe and forepart region thereof are gripped and thereafter the upper, while remaining so gripped, is tensioned about its last. Thereafter, the heel end of the shoe is engaged in the back seam region of the shoe by a heel rest which provides support for the heel end of the shoe and, with the heel end thus supported and with the upper held thus tensioned, lasting marginal portions of the shoe upper, in the toe and forepart region thereof, are wiped over and pressed against corresponding marginal portions of the insole, the gripping of the upper being discontinued in timed relation with the wiping thereof. In carrying out such a method, for tensioning the upper either the pincers can be moved downwardly or the last support moved upwardly, or both movements may be effected. Whichever the movement or combination of movements selected, however, it is generally regarded as desirable that, prior to wiping being initiated as aforesaid, the heightwise position of the last support be such that the bottom of a shoe supported thereby lies generally in a plane in which the inwiping movement is effected (usually referred to as "the wiping plane"). For ensuring that the heightwise position of the last support is so set, furthermore, manually operable means is provided in conventional pulling over and lasting machines for effecting adjusting movement of the last support heightwise. The reason for ensuring that the shoe is supported with its bottom in the wiping plane is to ensure that, where wiper plates are used to effect the inwiping movement, on the one hand those plates can readily pass beneath the shoe bottom - that is to say, to ensure that they do not collide with the side of the shoe - while on the other hand to ensure that they do not miss contacting the shoe entirely. The leading edges of wiper plates tend to have chamfers so that a relatively thin leading edge portion can first engage below the shoe and thereafter, as the inward movement continues, the wiper plates engage the shoe with a progressively increasing force. If necessary, according to the setting of the last support, furthermore, the wiper plates can then lift the shoe entirely from engagement with the last support. It will of course be appreciated that during the wiping movement a toe pad will already have been brought into contact with the other surface of the toe of the shoe and the wipers will thus press the shoe against such pad. By thus setting the heightwise position of the last support a significant force may be applied to the shoe bottom during the inwiping movement of the wiper plates and this may lead in some circumstances to an undesirable further tensioning of the shoe upper, with a result that it is over-stretched or indeed damaged by the wiper plates' action. Moreover, the bottoms of many shoes exhibit a significant curvature, so that by supporting a central region of the shoe on the last support, the heightwise position of the edges of the shoe bottom (i.e. the featherline) will not be in the correct heightwise position for the initiation of the wiping operation if the last support itself lies in the wiping plane. What is more, the divergence between the heightwise position of the edges of the central portion of the shoe bottom will vary, for a given style of shoe, according to the size thereof. OBJECTS OF THE INVENTION It is thus one of the various objects of the present invention to provide an improved method of pulling over and lasting toe and forepart portions of shoes wherein a closer control of the heightwise position of the last support in relation to the shoe bottom can be achieved. It is another of the various objects of the present invention to provide an improved pulling over and lasting machine for use in carrying out a method as referred to above. SUMMARY OF THE INVENTION The invention thus provides, in one of its several aspects, a method of pulling over and lasting toe and forepart portions of shoes comprising placing the shoe, comprising an upper on a last and an insole on the last bottom, on a last support, gripping lasting marginal portions of the shoe upper in the toe and forepart region thereof and thereafter, while the upper remains so gripped, tensioning it, supporting the heel end of the shoe by a heel rest engageable with the shoe in the back seam region thereof, and, with the heel end thus supported and with the upper held thus tensioned, wiping the lasting marginal portions over and pressing them against corresponding marginal portions of the insole, the gripping of the upper being discontinued in timed relation with the wiping thereof, characterised by setting the heightwise position of the last support, prior to wiping being initiated as aforesaid, in accordance with the length of the shoe. Moreover, conveniently in carrying out such method the heightwise position of the last support prior to wiping being initiated as aforesaid is set in accordance with the distance through which the heel rest is moved from its out- of-the-way position into engagement with the back seam region of the shoe. It will be appreciated that, using such a method, the heightwise position of the last support is now related specifically to a dimensional feature, either of the last itself or of an integer of the machine by which the method is to be carried out, so that the setting of the heightwise position of the last support is no longer dependent solely upon an empirical act of the operator, but rather relies on a readily ascertainable feature. The invention further provides, in another of its several aspects, a pulling over and lasting machine comprising a last support for supporting, bottom down, the toe/forepart region of a shoe comprising an upper on a last and an insole on the last bottom, a plurality of pincers arranged in a generally U-shaped array about the last support, for gripping lasting marginal portions of a shoe supported by the last support, means for effecting relative heightwise movement between the last support and the pincers whereby a shoe upper gripped as aforesaid can be tensioned about its last, a heel rest movable from a predetermined out-of-the-way position into pressing engagement with the back seam region of a shoe, and a wiper assembly for wiping said lasting marginal portions of the toe and forepart regions of the upper inwardly over and pressing them against corresponding marginal portions of the insole, the pincers being arranged to release their grip on the lasting marginal portions in timed relation with the inwiping movement of the wiper assembly, wherein prior to the initiation of such inwiping movement the heightwise position of the last support is such that the shoe bottom lies generally in a plane in which the wiper assembly effects its inwiping movement, characterised in that a position-detecting device is associated with the heel rest and generates a signal having a value corresponding to the distance moved by the heel rest from its out-of-the-way position into engagement with the back seam region of the shoe, and in that electronic control means is provided by which the heightwise position of the last support is determined in accordance with the value of such signal. It will thus be appreciated that, using such a machine, the actual distance moved by the heel rest, which is of course equivalent to measuring the length of the shoe, can be effected in the machine and, in response to such measurement having been made, the heightwise position of the last support can be automatically set. Conveniently in the machine in accordance with the invention, motor means is provided for effecting heightwise movement of the last support, and in addition stop means is provided for determining the upper position to which the last support is moved by the motor means, said stop means comprising a stop member the position of which is adjustable in accordance with the value of the signal generated by the position-detecting device. Moreover, preferably an n.c. motor is provided for adjusting the position of the stop member in accordance with said signal value. (By the phrase "n.c. motor" where used herein is to be understood a motor the operation of which is controlled by control signals supplied thereto in accordance with stored information appropriate to a desired operation. Examples of such motors are stepping motors and n.c. servo motors.) Preferably, furthermore, in said machine there are provided two stop means, a first for determining a first heightwise position to which the last post is moved by the motor means, and a second for determining a second heightwise position to which it is thereafter moved by said motor means, each of the stop means comprising a stop member. In such a case, furthermore, preferably the position of the stop member of the first stop means can be adjusted, e.g. according to the style of shoe to be operated upon, while the position of the stop member of the second stop means is adjustable in accordance with the value of the signal generated by the position-detecting device. In such a case, furthermore, preferably each stop means comprises an n.c. motor for adjusting the position of the stop member thereof. It will thus be appreciated that, by the provision of n.c. motors as aforesaid, the setting of the or each stop member can be accurately controlled in accordance with signals supplied to the control means. In the case of the stop means for determining the heightwise position of the last support immediately before wiping is initiated the signal is of course that supplied by the position-detecting device. Where two stop means are provided as aforesaid, the first may be supplied with an appropriate positioning signal based upon pre-programmed data relating to a particular style of shoe to be operated upon. Where two stop means are provided as aforesaid, furthermore, preferably the motor means for effecting heightwise movement of the last support comprises two motors arranged one behind the other, whereby operation of one of said motors is effective to move the last support to said first heightwise position and operation of the other motor is effective to move the last support to said second heightwise position. A relatively straightforward arrangement is thus achieved for achieving the desired control of the two heightwise positions for the last support. It will be appreciated that if desired further stop means may also be provided for determining the lowermost position of the last support, said further stop means comprising a further stop member the position of which can be adjusted e.g. according to the style of the shoe to be operated upon, together with an n.c. motor for adjusting the position of said further stop member. BRIEF DESCRIPTION OF THE DRAWINGS The above and other of the various objects and several aspects of the invention will be found set out in the following detailed description, to be read with reference to the accompanying drawings, of one pulling over and lasting machine in accordance with the invention, the operation of which machine constitutes a method illustrative of the invention in its method aspects. It will of course be understood that this machine and this method have been selected for description merely by way of non-limiting example. In the accompanying drawings:- Figure 1 is a front perspective view of said one machine in accordance with the invention; Figure 2 is a fragmentary view showing details of a heel rest of the machine of Figure 1; Figure 3 is a fragmentary view, partly in section, showing details of motor means for effecting heightwise movement of a last support of said machine, showing also various stop means for controlling the position to which the last support is moved under the action of the motor means; and Figure 4 is a diagrammatic representation showing the relationship between wiper plates of a wiper assembly of said machine, the last support and two shoes of different sizes. DESCRIPTION OF THE PREFERRED EMBODIMENT The pulling over and toe lasting machine shown in Figure 1 is generally of conventional design, except as hereinafter described. Thus, the machine comprises a last support 10 for supporting, bottom down, the forepart of a shoe, a generally U-shaped so-called imprinter plate 12 which can be pressed against marginal portions of the toe and forepart region of an insole of a shoe supported by the last support 10 thus to cause adhesive to be applied to said marginal portions, a pincer assembly generally designated 14, a wiper assembly comprising two wiper plates 20, a toe band 22, a toe pad 24 and a heel rest arrangement generally designated 26. The machine also comprises a control panel 28 and a keyboard and monitor unit 30 mounted on a frame of the machine. For controlling operation of the machine, furthermore, a foot switch FS1 is also provided. Turning to Figure 4, it will be apparent that where the shoe last bottom has a lateral contour which is curved, then lasts of different sizes will be located at different heights in relation to the wiper plates 20. In Figure 4 are shown two lasts, and it will be clear that the bottom of the larger last (LI) has a higher position in relation to the wiper plates 20 than that of the smaller last (L2) . If, therefore, the last support 10 is moved to a pre-set position for the particular style of shoe, regardless of the size thereof, it will be apparent that the forces applied to the last bottom will vary according to the size of the shoe. For example, if the last support 10 is positioned as shown in chain-dot line in Figure 4, then the forces applied to the shoe on the larger last LI would be significantly greater than those applied to the shoe on the smaller last L2. If on the other hand the last support 10 is positioned as shown in dotted line in Figure 4, then the wipers 20 will scarcely contact the bottom of the shoe on the smaller last. In generally, therefore, using conventional machines a compromise would tend to be made, namely by setting for a middle size, or alternatively the operator is required to make manual settings of the last support height. Whereas in the case of shoe uppers of relatively hard material variations in wiping pressure do not have a significant effect on the upper material, in the case of light, e.g. calf, shoe uppers too great a wiping pressure may well have a detrimental effect on the finished shoe, if not indeed a damaging effect on the upper material itself. In accordance with the present invention, therefore, provision is made for automatically setting the height of the last support 10 not only in accordance with the style of shoe being operated upon, but also in accordance with the size thereof. To this end, firstly a linear potentiometer 38 is associated with the heel rest 26, as will now be described in detail with reference to Figure 2. The heel rest 26 comprises a bracket 40 mounted on the machine frame and supporting a guide 42 extending heightwise of the machine, in which guide a block 44 is mounted for heightwise sliding movement, a clamp arrangement 46 being provided for locking the block in adjusted heightwise position. Integral with the block 44 is a piston-and-cylinder arrangement 48 on a piston rod 50 of which is mounted a support block 52 in which is supported, for sliding movement transversely of the machine, a carrier 54 for a heel block 56. The heel block 56 constitutes a heel-engaging member. Integral with the support block 52 is a piston-and-cylinder arrangement (not shown) by which the carrier 54 can be moved transversely between a "left shoe" and a "right shoe" position, in which respectively the heel block 56 is positioned for operating on a left or a right shoe. In the operation of the machine actuation of the piston-and-cylinder arrangement 48 is effective to move the heel block 56 towards the last support 10 thus to engage the heel end of a shoe supported thereby; in this way, the heel block serves to hold the shoe in position on the last support 10. (It will be appreciated that, as in other conventional pulling over and toe lasting machines, instead of fixing the position of the bracket 40 and providing for powered sliding movement in a shoe-lengthwise direction of the heel block 56 by the piston-and-cylinder arrangement 48, the heel block 56 may be fixed against shoe-lengthwise movement relative to the mounting and the whole heel rest arrangement 26 be moved bodily in the shoe-lengthwise direction to bring the heel block 56 into and out of engagement with the shoe.) For monitoring the amount of movement of the heel block 56 towards the last support 10 under the action of piston-and- cylinder arrangement 48, the linear potentiometer 38 is supported on the block 44 and is thus connected with the cylinder of the piston-and-cylinder arrangement 48, while the core thereof is connected to the piston rod 50 of said arrangement 48. By thus monitoring the movement of the heel block 56 towards the last support 10, effectively the size of the shoe being operated upon is thus measured. The last support 10 is mounted on a post 60 slidable heightwise in a column 62 (Figure 3). For effecting heightwise movement of the post a double-cylinder arrangement generally designated 64 is provided, said arrangement comprising a first cylinder 66 in which a piston 68 is accommodated, a piston rod 70 of said piston 68 projecting downwardly from the cylinder 66 and carrying at its remote end an abutment block 72. This block 72 cooperates with a switch 74 whereby the stroke of the piston 68 in the cylinder 66 is controlled. More particularly, the control of the stroke of the piston 68 as aforesaid is dependent upon the style of the shoe being operated upon, to which end the abutment block 72 is threadedly secured to the piston rod 70, means (not shown, but including an n.c. motor) being provided for effecting rotation of the block 72 on the piston rod 70, thus to vary its heightwise position thereon. The piston 68 also has an upwardly projecting piston rod 68a which projects through the upper end of the cylinder 66 and can engage with a piston 76 accommodated in a further cylinder 78 mounted co-axially with the cylinder 66. An upwardly projecting piston rod of the piston 76 supports the post 60. By admission of fluid under pressure to the cylinder 78, therefore, the post 60, and thus the last support 10, can be moved further upwardly in the column 62. The lowermost position of the last support 10 is controlled by a stop member 80 threadedly secured in a flange 82 formed on the column 62, the stop member 80 cooperating with an abutment plate 84 supported on the post 60 and projecting through an aperture formed in the column 62. For varying the lowermost position of the post 60, and thus of the last support 10, furthermore, means (not shown, but including an n.c. motor) is provided for rotating the stop member 80 in the flange 82 thus to vary its heightwise position in relation to the flange. In t .'.s way, the travel of the abutment plate, and thus of the last support 10, can be varied. Similarly, the upper position of the post 60, and thus of the last support 10, is controlled by a stop member 90 which in this case is threadedly supported in the abutment plate 84 and engages with an abutment surface 92 provided by a further aperture 94 in the column 62, through which the plate 84 projects. Similarly, furthermore, for varying the upper position to which the last support 10 can be moved, the stop member 90 is threadedly received in the abutment plate 84 and means (not shown, but including an n.c. motor) is provided for varying its position relative to the abutment plate 84 and thus varying the travel of the abutment plate heightwise relative to the column 62. The machine also includes electronic control means, including a computer having a memory in which sets of data can be stored relating to different styles of shoe to be operated upon. As part of each set of data information is stored relating to a desired heightwise position of the last support 10 for the particular style of shoe and to this end, when a particular set of data is selected, e.g. through the keyboard 30, the n.c. motor associated with the abutment block 72 is operated to rotate that abutment block to take up a position determined according to the data selected. In this way, an initial setting for the last support height is made. When therefore a cycle of operation of the machine is initiated, fluid under pressure is admitted to the cylinder 66 until the abutment block 72 actuates switch 74, whereupon the supply of fluid is discontinued. Also as part of the particular set of data is a further value which relates to the degree of curvature of the last bottom. This value can then be modified according to the length of the shoe as measured by the linear potentiometer 38 and an appropriate control signal can then be supplied to the n.c. motor by which the position of the stop member 90 in the abutment plate 84 can be carried, such variation thus being proportional to the length of shoe as measured. Varying the position of the stop member 90, it will be appreciated, thus varies the amount of movement which the post 60, and thus the last support 10, can undergo when fluid under pressure is supplied to the cylinder 78. It will thus be appreciated that by varying the upper position of the last support 10 in the aforementioned manner shoes of a given style but different sizes can be supported by the last support 10 appropriately to the wiping pressure which is to be applied to the shoe during the inwiping movement of the wipers. In using the machine in accordance with the invention, in carrying out a method in accordance with the invention, a shoe is first placed on the shoe support 10 and, in a conventional manner, lasting marginal portions of the shoe upper are gripped by the pincers 14 and thereafter relative heightwise movement is effected between the pincers 14 and the last support 10 whereby to tension the shoe upper over its last. In the machine here being described, the tensioning of the upper in this manner is effected by not only movement upwards of the last support 10, under the action of piston-and-cylinder arrangement 66,68, but also by downward movement of the pincers themselves. With the shoe upper thus tensioned, the heel block 56 of the heel rest 26 is then moved into engagement with the back seam region of the shoe under the action of piston-and-cylinder arrangement 48 and is locked in this position. At this stage, in the machine described above the output value of the linear potentiometer 38, which is representative of the shoe length, is supplied as an input signal to the electronic control means and consequent upon receipt of this signal a drive signal is supplied to the n.c. motor controlling the position of the stop member 90, whereby said member is adjusted in the abutment plate 84. Following the positioning of said stop member, fluid under pressure is then admitted to the cylinder 78 and the last support 10 is then moved further heightwise into its operative position, appropriate to the shoe being operated upon. It will thus be appreciated that, using the illustrative method, the heightwise position of the last support 10 is dependent upon the length of the shoe as measured by the linear potentiometer 38 and in this way an improved lasting of shoes, especially shoes on a last having a significant bottom curvature, can be achieved.

Claims: Claims ; 1. A method of pulling over and lasting toe and forepart portions of shoes comprising placing the shoe, comprising an upper on a last and an insole on the last bottom, on a last support (10), gripping the lasting marginal portions of the shoe upper in the toe and forepart region thereof and thereafter, while the upper remains so gripped, tensioning it, supporting the heel end of the shoe by a heel rest (26) engageable with the shoe in the back seam region thereof, and, with the heel end thus supported and with the upper held thus tensioned, wiping the lasting marginal portions over and pressing them against corresponding marginal portions of the insole, the gripping of the upper being discontinued in timed relation with the wiping thereof, characterised by setting the heightwise position of the last support (10), prior to wiping being initiated as aforesaid, in accordance with the length of the shoe. 2. Method according to Claim 1 characterised by setting the heightwise position of the last support (10) in accordance with the distance through which the heel rest (26) is moved from its out-of-the-way position into engagement with the back seam region of the shoe. 3. A pulling over and lasting machine comprising a last support (10) for supporting, bottom down, the toe/forepart region of a shoe comprising an upper on a last and an insole on the last bottom, a plurality of pincers (14) arranged in a generally U-shaped array about the last support (10), for gripping lasting marginal portions of a shoe supported by the last support ( 10 ) , means for effecting relative heightwise movement between the last support (10) and the pincers (14) whereby a shoe upper gripped as aforesaid can be tensioned about its last, a heel rest arrangement (26) movable from a predetermined out-of-the-way position into pressing engagement with the back seam region of a shoe, and a wiper assembly (20) for wiping said lasting marginal portions of the upper inwardly over and pressing them against corresponding marginal portions of the insole, the pincers (14) being arranged to release their grip on the lasting marginal portions in timed relation with the inwiping movement of the wiper assembly (20), wherein prior to the initiation of such inwiping movement the heightwise position of the last support (10) is such that the shoe bottom lies generally in a plane in which the wiper assembly (20) effects its inwiping movement, characterised in that a position-detecting device (38) is associated with the heel rest (26) and generates a signal having a value corresponding to the distance moved by the heel rest (26) from its out-of-the-way position into engagement with the back seam region of the shoe, and in that electronic control means is provided by which the heightwise position of the last support (10) is determined in accordance with the value of such signal. 4. Machine according to Claim 3 wherein motor means (64) is provided for effecting heightwise movement of the last support (10), characterised in that stop means (90,92) is provided for determining the upper position to which the last support (10) is moved by the motor means (64), and in that said stop means (90,92) comprises a stop member (90) the position of which is adjustable in accordance with the value of the signal generated by the position-detecting device (38) . 5. Machine according to Claim 4 characterised by an n.c. motor for adjusting the position of the stop member (90) in accordance with said signal value. 6. Machine according to Claim 3 wherein motor means (64) is provided for effecting heightwise movement of the last support (10) , characterised by first stop means (72,74) for determining a first heightwise position to which the last post (10) is moved by the motor means (64), and second stop means (90,92) for determining a second heightwise position to which it is thereafter moved by said motor means (64), and characterised in that each of the stop means (72,74; 90,92) comprises a stop member (72;90), and in that the position of the stop member (72) of the first stop means (72,74) can be adjusted according to the style of shoe to be operated upon, while the position of the stop member (90) of the second stop means (90,92) is adjustable in accordance with the value of the signal generated by the position-detecting device (38). 7. Machine according to Claim 6 characterised in that each stop means (72,74; 90,92) comprises an n.c. motor for adjusting the position of the stop member (72;90) thereof. 8. Machine according to Claim 6 characterised in that the motor means (64) for effecting heightwise movement of the last support (10) comprises two motors (66,68,68a; 76,78) arranged one behind the other, whereby operation of one (66,768,68a) of said motors is effective to move the last support (10) to said first heightwise position and operation of the other motor (76,78) is effective to move the last support (10) to said second heightwise position. 9. Machine according to Claim 4 wherein further stop means (80,84) is provided for determining the lowermost position of the last support (10), characterised in that the further stop means (80,84) comprises a further stop member (80) the position of which can be adjusted e.g. according to the style of the shoe to be operated upon, together with an n.c. motor for adjusting the position of said further stop member (80).

Inventors: GIEBEL GERHARD, GIEBEL, GERHARD
Applicants: BRITISH UNITED SHOE MACHINERY, DVSG ENG & PATENT, USM ESPANA SA, BRITISH UNITED SHOE MACHINERY LIMITED, DVSG ENGINEERING UND PATENTVERWALTUNGS GMBH, USM ESPANA, S.L.
Application year: 1993
Main classification: A43D119
IPC codes: A43D21, A43D119