HEEL REST ARRANGEMENT FOR A PULLING OVER AND LASTING MACHINE

Abstract: In a pulling over and lasting machine a heel rest arrangement (26) is provided, comprising a position-detecting device (linear potentiometer (52)) by which the actual position of the heel-engaging member (heel block (32)) can be monitored, comparator means being provided for comparing the value of the output of such device with a pre-set further value, representative of the desired heightwise position of the heel block (32). In response to a discrepancy arising between the two values, either a display (30) may indicate the discrepancy, in response to which the operator corrects the discrepancy, or powered means may be provided for automatically moving the heel block (32) to a corrected position. In another version, furthermore, locking means is provided which is released upon a discrepancy arising, allowing the operator to adjust the heightwise position of the heel block (32), whereafter the locking means (50) is automatically reapplied. The control is so organised that a cycle of operation cannot be initiated until no discrepancy is sensed.

Description: HEEL REST ARRANGEMENT FOR A PULLING OVER AND LASTING MACHINE BACKGROUND OF THE INVENTION This invention is concerned with improvements in or relating to a heel rest arrangement for a pulling over and lasting machine, comprising a mounting for a heel-engaging member, which mounting, and thus the heel- engaging member therewith, is supported for movement in a direction extending heightwise of the bottom of a shoe to be operated upon and also in a direction extending lengthwise of such shoe bottom. It will be appreciated that in a conventional pulling over and lasting machine after the upper of a shoe to be lasted has been placed on the shoe support and the upper has been gripped by pincers arranged about the shoe support, in order to prevent any dislodging of the shoe during a subsequent tensioning operation a heel rest arrangement is provided. In general, the heel rest arrangement will comprise a heel-engaging member, which may be pivotally mounted, for engaging the back seam region of the shoe, about a pivot supported on a mounting, the mounting being in turn supported for movement in the shoe-lengthwise direction in order to accommodate to different sizes of shoe last. Moreover, bearing in mind that according to the heel height of the shoe the back seam region thereof will be located at different locations heightwise of the shoe, the mounting for the heel-engaging member is itself mounted for heightwise movement thus to accommodate to shoes of different heel height. At the present time the adjustment of the heightwise position of the heel-engaging member is at the discretion of the operator. Such adjustment entails the release of locking means, heightwise adjustment of the mounting and the re-application of the locking means, all such operations being carried out manually. In the course of a working day, if such adjustments are constantly being required, e.g. where shoes of different styles and sizes are passing through the production line, the demands on the operator in terms not only of time but also effort are significant. Moreover, bearing in mind that the operator will normally be concerned to ensure relatively high productivity, there will be a tendency for him to compromise on the heightwise position of the mounting, rather than always to be adjusting it according to the particular shoe being operated upon. In recent times it has been proposed to render automatic the positioning of various integers of a pulling over and lasting machine according to the size and/or style of the shoe to be operated upon, to which end sets of parameters according to each style and/or size are stored and, by selecting a particular set of parameters e.g. through a keyboard, the machine then is automatically set to the various parameters as pre¬ programmed. In general, however, the heightwise setting of the mounting for the heel-engaging member remains a manual function. It will of course be appreciated that where the operator is relied upon for setting the heightwise position, then reliance is essentially placed on the experience of the operator in order that the heel- engaging member be positioned correctly. OBJECT OF THE INVENTION It is thus one of the various objects of the present invention to provide an improved heel rest arrangement for a pulling over and lasting machine wherein the setting of the heightwise position of the heel-engaging member is less demanding upon the operator in terms of time and effort and also wherein the accuracy of the positioning of the heel-engaging member can be enhanced. SUMMARY OF THE INVENTION The invention thus provides, in one of its several aspects, in a pulling over and lasting machine a heel rest arrangement comprising a mounting for a heel- engaging member, which mounting, and thus the heel- engaging member therewith, is supported for movement in a direction extending heightwise of the bottom of a shoe to be operated upon and also in a direction extending lengthwise of such shoe bottom, said arrangement also comprising a position-detecting device by which a signal is generated having a value corresponding to the actual heightwise position of the mounting, means for inputting a value representing a desired heightwise position of the mounting, and comparator means for comparing the two values. in such a machine, moreover, preferably locking means is provided for locking the mounting in adjusted heightwise position, and actuator means is provided, operable in response to a discrepancy between the two values when compared by the comparator means, to release the locking means and, after the mounting has been moved to a position where said values match, to re-apply the locking means. In one embodiment of the invention the mounting is manually movable heightwise, and indicator means is provided by which an indication is displayed in the event of a discrepancy between the two values when compared by the comparator means. In another embodiment of the invention, on the other hand, power means may be provided for effecting heightwise movement of the mounting, said power means being actuated in response to a discrepancy between the two values when compared by the comparator means . Whichever embodiment is selected, conveniently the mounting is supported under a balanced pressure. As a further feature, moreover, conveniently the position- detecting device comprises a linear potentiometer. It will thus be appreciated that, using the heel rest arrangement in accordance with the present invention, firstly the actual position to which desirably the heel-engaging member is to be moved can be predetermined and the setting can be stored in a computer memory for access via e.g. a keyboard. In this way, therefore, the task of the operator in determining the correct position of the heel rest arrangement for a given style and/or size of shoe is reduced and moreover, once the setting has been made, reliance need no longer be placed on his experience and skill. Moreover, by the provision of actuator means for releasing and re-applying the locking means the operator need now only concentrate on the movement of the mounting to the correct heightwise position and the locking and unlocking of the mounting is taken care of automatically. Furthermore, where the mounting is manually moved, the provision of the indicator means, which may be e.g. a visual display either on a screen or via a lamp or the like, dispenses with the need for the operator to exercise skill and experience in moving the mounting to its desired heightwise position, the operator now being required only so to move it until the visual display changes to indicate that a correct positioning has been achieved; where, therefore, a display on a screen is used, either the display may be changed or the display may be removed from the screen, while in the case of a lamp or the like the lamp need merely be switched off. In the "powered" version, on the other hand, it is not necessary to provide any indicator, but rather the power means is merely actuated in response to any discrepancy thus to correct it, again of course under the control of the comparator means. By the provision of a balanced pressure for supporting the mounting, furthermore, whether the setting of the heightwise position of the mounting is achieved manually or under power, the force required for moving it heightwise is significantly reduced; this is of course of particular benefit in the manual version. It will thus be appreciated that, using a heel rest arrangement in accordance with the present invention, as set out above, in either of the above embodiments the time and/or effort required for re¬ setting according to different styles and/or sizes of shoe can be significantly reduced, leading to less operator fatigue and enhanced productivity. BRIEF DESCRIPTION OF THE DRAWINGS There now follows a detailed description, to be read with reference to the accompanying drawings, of one heel rest arrangement in accordance with the invention. It will of course be appreciated that this heel rest arrangement has been selected for description merely by way of non-limiting example of the invention. In the accompanying drawings:- Figure 1 is a perspective view of a pulling over and toe lasting machine incorporating a heel rest arrangement in accordance with the invention; and Figure 2 is a fragmentary plan view showing details of the heel rest arrangement. 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 shoe 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 forepart of an insole of a shoe supported by the shoe support 10 thus to cause adhesive to be applied to said marginal portions, together with 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. In the machine above described the heel rest arrangement 26 comprises a heel-engaging member in the form of a heel block 32 (Figure 2) which is supported, for pivotal movement about an axis extending widthwise of the bottom of a shoe to be operated upon, in a bracket 34. The bracket 34 is secured on a carrier 36 itself mounted for sliding movement, in a direction extending widthwise of the bottom of a shoe to be operated upon, in a support block 38 carried by a piston rod 40 of a piston-and-cylinder arrangement 42. For effecting widthwise sliding movement of the carrier 36, furthermore, a piston-and-cylinder arrangement is provided the cylinder of which is constituted by the support block 38. In this way, the carrier 36, and thus the heel-engaging member 32, can be moved transversely between a "left shoe" and a "right shoe" position, in which respectively the heel block 32 is positioned for operating on a left or a right shoe. The piston-and-cylinder arrangement 42 is itself formed integral with a mounting 44 which is mounted for sliding movement, in a direction extending heightwise of the bottom of a shoe to be operated upon, in a guide 46. The guide 46 is supported by a bracket 48 which in turn is supported on a slide (not shown) for adjusting movement in a direction extending lengthwise of the bottom of a shoe to be operated upon as in a conventional pulling over and toe lasting machine. For locking the mounting 44 in its heightwise adjusted position, a locking or clamp device generally designated 50 is provided; for securing the bracket 48 in its lengthwise adjusted position, appropriate clamp screws (not shown) are provided. (It will be appreciated that, as in other conventional pulling over and toe lasting machines, instead of fixing the position of the bracket 48 and providing for powered sliding movement in a shoe- lengthwise direction of the heel block 32 by the piston- and-cylinder arrangement 42, the heel block 32 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 32 into and out of engagement with the shoe.) In the operation of the machine shown in the drawings, with the bracket 48, and thus the heel rest arrangement 26, appropriately set in the shoe-lengthwise direction according to the particular type of shoe being operated upon (usually men's, women's or children's), actuation of the piston-and-cylinder arrangement 42 is effective to move the heel block 32 towards the shoe support of the machine thus to engage the heel end of a shoe supported thereby; in this way, the heel block 32 serves to hold the shoe in position on the shoe support 10. At the end of each operating cycle, furthermore, the heel block is automatically switched from its "left shoe" to its "right shoe" position or vice versa, as the case may be. A proximity switch PrS is provided on the support block 38 and monitors the movement of the carrier 36, generating a signal accordingly which indicates whether the shoe being operated upon is a left or a right. In the machine now being described, a position- detecting device in the form of a linear potentiometer 52 is carried by a bracket 54 formed on the guide 46 and the slider 56 of the potentiometer is connected at one side of the mounting 44. Thus, as the mounting 44, and thus the heel block 32, is moved heightwise in relation to the guide 46, the output of the linear potentiometer 52 will vary accordingly. By supplying an output voltage from the linear potentiometer, therefore, to suitable control means, the actual heightwise position of the heel- engaging member at any given time can be monitored. The heel rest arrangement 26 in accordance with the invention has associated therewith an electronic control device, including the keyboard and monitor 30, by which for different styles and/or sizes of shoe to be operated upon the input and storing of sets of data is facilitated. As part of each set of data, moreover, a desired value can be set which is representative of the optimum heightwise position of the heel block 32 for the particular style to which the set of data relates. The electronic control means, furthermore, also comprises comparator means whereby the output value of the linear potentiometer 52, which may be converted to a digital value for this purpose, can be compared with the desired value and, in the event of any discrepancy between the two values, a signal is generated in response to which certain events are caused to take place, as hereinafter described in detail, according to the particular construction and operation of the heel rest arrangement. Thus, in a first version of heel rest arrangement, in the event of a discrepancy as aforesaid, a "window" is displayed on the monitor 30 indicating that the actual position of the heel block 32 does not correspond with that set for the particular style, as indicated in the pre-programmed data. When such a signal is given, the operator must then release the locking arrangement 50, raise or lower the mounting 44 until the window is removed from the screen, thus indicating that the heel block 32 is correctly positioned, and then re- apply the locking device 50. Instead of a window displayed on the monitor, it will be appreciated, other indicators could be used, e.g. a lamp or the like. In another version of the heel rest arrangement 26, the locking means 50 is not manually operable, but rather is operated by power means (not shown, but comprising e.g. a piston-and-cylinder arrangement attached to the handle of said means). In this case, in the event of a discrepancy, the power means is actuated to release the locking means 50, and at the same time a window is displayed on the monitor. The operator must then manually adjust the heightwise position of the mounting 44 in the same manner as the previously described version, and, upon the actual position matching the desired position, the window is removed from the screen and the locking means 50 is automatically re- applied by actuation of the power means. It will of course be realised that other powered locking means may be provided to achieve the same purpose as just described. In a still further version, powered means (not shown) is provided for effecting heightwise movement of the mounting 44 on the guide 46, powered locking means (not shown) being also provided. In this case, the display of a window can be dispensed with and, in the event of a discrepancy as aforesaid, the powered means is operated to move the mounting 44 heightwise to bring the heel block 32 to an actual position which matches the desired position, as determined by the pre-programmed data. At the end of this adjusting movement, the powered locking means is re-applied. In order to reduce the work required by the operator in the first two versions, a balanced pressure or "air spring" is provided to support the mounting 44 and the mechanism supported by it; in the case of the third version, furthermore, where the powered means comprises e.g. a stepping motor, again a balancing pressure may be also applied to the mounting 44 in order to reduce the work done by said motor. In order to ensure that the heel rest arrangement 26 is correctly positioned in accordance with the requirements of the shoe to be operated upon, where a discrepancy arises as aforesaid, the electronic control means may be so arranged as to prevent a cycle of operation of the machine from being initiated.

Claims: Claims : 1. In a pulling over and lasting machine a heel rest arrangement (26) comprising a mounting (44) for a heel-engaging member (32), which mounting (44), and thus the heel-engaging member (32) therewith, is supported for movement in a direction extending heightwise of the bottom of a shoe to be operated upon and also in a direction extending lengthwise of such shoe bottom, characterised by a position-detecting device (52) by which a signal is generated having a value corresponding to the actual heightwise position of the mounting (44), means for inputting a value representing a desired heightwise position of the mounting, and comparator means for comparing the two values. 2. A heel rest arrangement according to Claim 1 wherein locking means (50) is provided for locking the mounting (44) in adjusted heightwise position, characterised by actuator means, operable in response to a discrepancy between the two values when compared by the comparator means, to release the locking means (50) and, after the mounting (44) has been moved to a position where said values match, to re-apply the locking means (50). 3. A heel rest arrangement according to Claim 1 wherein the mounting (44) is manually movable heightwise, characterised by indicator means (30) by which an indication is displayed in the event of a discrepancy between the two values when compared by the comparator means. 4. A heel rest arrangement according to Claim 1 characterised by power means for effecting heightwise movement of the mounting, said power means being actuated in response to a discrepancy between the two values when compared by the comparator means. 5. A heel rest arrangement according to Claim 1 characterised in that the mounting (44) is supported under a balanced pressure. 6. A heel rest arrangement according to Claim 1 characterised in that the position-detecting device (52) comprises a linear potentiometer (52). 7. A heel rest arrangement according Claim 1 characterised in that in the event of a discrepancy between said values a disabling signal is generated whereby operation of the machine of which the heel rest arrangement forms part is disabled.

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