Abstract:
In a pulling over and lasting machine in addition to a toe pincer there are provided two sets of side pincers, each set being mounted on a support pivotal about an axis extending heightwise of the shoe bottom and passing through or adjacent the toe pincer. Each pincer is adjustably mounted on its support but in addition each set is movable bodily, through its support, about its axis. In one embodiment the supports are movable only in opposite directions, i.e. towards and away from one another, thus to accommodate to shoes of different widths. In a second embodiment, on the other hand, in addition these supports are also movable in the same direction, thus to cause the pincers to be accommodated to left and right shoes. 
     For clamping the shoe at its heel end, a heel rest is provided the transverse position of which is dictated solely by the heel end of the shoe without applying to the shoe any significant forces tending to re-orient it, this being achieved by allowing free movement with low friction transversely of the longitudinal centerline.

Description:
BACKGROUND OF THE INVENTION 
     This invention is concerned with pulling over and toe lasting machines comprising a shoe support for supporting, bottom down, a shoe comprising an upper on a last and an insole on the last bottom, a plurality of pincers including at least one toe pincer and two sets of side pincers, the pincers being arranged in a generally U-shape about the shoe support for gripping lasting marginal portions of the shoe upper and tensioning the upper about its last, and a wiper assembly by which lasting marginal portions of the upper tensioned as aforesaid are wiped over and pressed against corresponding marginal portions of the insole, the assembly comprising two wiper plates disposed symmetrically at opposite sides of the longitudinal center line of the operating locality of the machine. 
     Machines of the aforementioned type are generally well known and conventional, see e.g. GB-A No. 2114868. Furthermore, in order to be able to accommodate the side pincers to different shoe widths, in machines of the aforementioned type each pincer is mounted for individual adjusting movement relative to the shoe support both lengthwise and widthwise of the bottom of a shoe supported thereby, thus to enable the operator to adjust the position of the pincers to the particular size and style of shoe being operated upon. In practice, however, it has been found that the operator tends to set the side pincers merely to the shape of the largest shoe in order to avoid the time-consuming individual adjustment of the side pincers in order to accommodate smaller shoes. Such a practice, however, does not enable the best lasting results to be obtained from the machine. 
     Also in pulling and lasting machines of the aforementioned type, it is desirable that the machine can readily operate on both left and right shoes without the need for the operator to adjust the pincers for that purpose. In setting up the machine, the operator will usually arrange the pincers symmetrically about a longitudinal centerline(s) of the operating locality of the machine, about which centerline(s) the wipers are also disposed symmetrically. This is justified in that the toe end of a shoe is generally considered to be symmetrical about a longitudinal centerline(s) of the toe end region, which line runs lengthwise of the shoe and intersects the toe end thereof. However, such symmetry extends only over a relatively small portion of the toe end of the shoe so that in what may be termed the forepart region, lying between the toe end and ball region, the shoe bottom is not symmetrical but rather, if the longitudinal centerline(s) of the operating locality and of the toe end region are in alignment, the &#34;inside&#34; forepart region of the shoe will be spaced further from the pincers than the &#34;outside&#34; forepart region. To accommodate this, furthermore, in practice the operator sets the pincers to such &#34;outside&#34; region. Such setting has the effect of unevenly pulling the upper on the last, thereby detracting from the achievement of optimum lasting results. It would not, however, be practicable using a conventional machine for the operator to set the side pincers for left and right shoes individually. 
     It has been proposed in GB-A No. 871990 to allow the pincers to move individually, i.e. independently of one another, from an outwardly spaced position inwardly to a position determined by engagement with the shoe bottom periphery of an abutment associated with each pincer, thereby setting the position of each pincer automatically according to the periphery of the shoe bottom. This arrangement however leads to an expensive machine construction which cannot be considered to be justified in terms of enhanced performance. 
     Furthermore, it is proposed in U.S. Pat. No. A 1441210 to provide, in a pulling over machine, a toe pincer and two side pincers arranged one at each side of the toe pincer, the side pincers each being mounted on a swinging arm the axis of rotation of which extends approximately vertically to the shoe bottom, one at each side of the toe pincer, and locking means being provided for securing each arm in adjusted position. In this way, the operator can readily re-position each pincer, thus to accommodate two shoes of different widths. With this arrangement however, the swinging of the arm provides the only adjustment of each pincer; that is to say the pincer is not adjustable relative to the arm. Consequently such an arrangement would not be suitable for incorporation into currently available pulling over and lasting machines, where more than one pincer would have to be mounted on each arm and be adjustable to accommodate different styles of shoe. Furthermore, even if such an arrangement were used, it could be expected that adjustment by the operator would be made only infrequently, as is the current practice (see above). 
     OBJECT OF THE INVENTION 
     It is thus the object of the present invention to provide an improved pulling over and toe lasting machine of the aforementioned type, wherein the side pincers can be positioned independently of one another according to the style of the shoe being operated upon, while maintaining a closed pincer formation, but also each set of side pincers is movable in a predetermined way in order to be positioned more appropriately to the particular shoe being operated upon. 
     SUMMARY OF THE INVENTION 
     This object is resolved in accordance with the present invention, in a machine as set out in the first paragraph above, in that each set of side pincers is supported on a support mounted for pivotal movement about an axis extending heightwise of the shoe bottom and passing through or adjacent the toe pincer(s), and in that side pincer orienting means is provided which is operatively connected to each of the supports and, in response to a signal indicating whether the next shoe to be operated upon is a left or a right, moves the supports accordingly to bring the sets of side pincers into a desired orientation with the shoe support means. 
     It will thus be appreciated that in the above solutions, each set of side pincers, on its support, is moved bodily to accommodate the &#34;hand&#34; of shoe being operated upon. 
     In the conventional machines referred to above, a heel rest is usually provided which is movable in a direction extending transversely of the longitudinal centerline to accommodate to the heel end of left and right shoes supported by the shoe support means. It will of course be appreciated that, where the longitudinal centerline of the toe end of a shoe is aligned with the longitudinal centerline of the operating locality, the heel end will tend to be displaced from the longitudinal centerline of the operating locality according to whether the shoe is a left or a right. The transverse movement of the heel rest is of course provided in order to accommodate to such variation. Conventionally, furthermore, the heel rest is powered to accommodate left or right shoes either under operator control, or automatically according to which &#34;hand&#34; of shoe is sensed, or indeed alternately. It is of course necessary, whichever system of moving is used, for the operator to set the position to which the heel rest is to be moved in either direction, which again is time-consuming. In the absence of such pre-setting, however, the position of the shoe in relation to both the pincers and the wipers could be detrimentally affected. 
     In accordance with the present invention, therefore, preferably the heel rest comprises a V-block and is spring-urged into a position in which the V is centralised on the longitudinal centerline, engagement of the heel rest with the heel end of a shoe being effective to cause the heel rest to be moved transversely appropriately to whether the shoe is a left or a right and also according to the amount by which the heel end of the shoe is offset from said longitudinal centerline. In this way, it will be appreciated, the position of the heel rest is dictated by the position of the heel end of the shoe, rather than vice versa, and consequently the heel rest, while properly holding the shoe in position, cannot influence its position. 
     In a preferred embodiment of machine in accordance with the invention, the pincer orienting means, when actuated, imparts equal displacement movements to each of the supports. More particularly, to this end conveniently the pincer orienting means comprises a single cylinder which acts on a pivotally mounted yoke to effect pivotal movement thereof, there being connected to the yoke at opposite sides of its pivot and equidistant therefrom two linkages which are also operatively connected one to each of the side pincer supports. One suitable linkage for this purpose is found to be constituted by a Bowden cable. The motor may conveniently be a fluid pressure operated piston-and-cylinder arrangement. 
     In this way, by a relatively simple arrangement, which can in fact be remote from the operating locality of the machine by reason of use of the Bowden cables, the sets of side pincers can be readily oriented for operating on left and right shoes. 
     In copending application Ser. No. 885,105, filed July 14, 1985 is disclosed a pulling over and toe lasting machine generally as set out in the first paragraph of this specification, wherein each set of side pincers is supported on a support mounted for pivotal movement about an axis extending heightwise of the shoe bottom and passing through or adjacent the toe pincer(s), and further wherein drive means is provided, operatively connected to each of the the pincer supports, for moving said supports relative to a longitudinal centerline of the operating locality of the machine through equal distances but in opposite directions (i.e. towards or away from each other) thus to accommodate to shoes of different sizes. 
     In accordance with the present invention such drive means may be combined to advantageous effect with the side pincer orienting means referred to above. 
     More particularly, the drive means of the machine in accordance with the present invention is preferably arranged for moving the support plates selectively between a plurality of pre-set positions. Furthermore, conveniently the drive means also operates through the yoke and linkages in order so to move the supports. To this end, conveniently the motor and pivot for the yoke are both mounted on a carrier which is movable to move the two linkages in the same direction (as opposed to causing the yoke to pivot), whereby the side pincer supports can be moved each through the same distance but in opposite directions (i.e. towards or away from each other) thus to accommodate to shoes of different sizes. It will of course be appreciated that such movement of the supports will not affect their left/right setting. 
     Conveniently the drive means comprises a single motor arrangement, the arrangement comprising a plurality of piston-and-cylinder arrangements mounted in tandem. In this way, by selectively operating the piston-and-cylinder arrangements, a plurality of pre-set positions for the supports for the pincers can be selected. The machine also comprises selecting means for this purpose. 
     It will thus be appreciated that, in using the machine in accordance with the present invention, the operator can, without the need for setting stops or the like, selectively position the sets of side pincers according to shoe size and also set the side pincers according to whether the shoe to be operated upon is a left or a right, such selection requiring a minimum of operator time and effort. 
     There now follows a detailed description, to be read with reference to the accompanying drawings, of two machines in accordance with the present invention. It will be appreciated that these two machines now to be described have been selected for description merely to illustrate the invention in its several aspects by way of non-limiting examples. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is a fragmentary plan view showing details of a pincer arrangement of the machine now to be described; and 
     FIG. 2 is a fragmentary view showing details of side pincer orienting means of the machine in combination with drive means whereby the side pincers can be set not only according to shoe size but also according to whether the shoe to be operated upon is a left or a right. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The machine now to be described is a pulling over and toe lasting machine comprising shoe support means comprising a toe support 10 and a heel rest generally designated 12 for supporting, bottom down, a shoe S comprising an upper on a last and an insole of the last bottom. An auxiliary shoe support function is also afforded by an adhesive-applying nozzle 14 which is generally U-shaped for applying a strip of adhesive about the toe and forepart end of the shoe bottom prior to lasting taking place. The machine also comprises a pincer assembly generally designated 16, comprising a toe pincer 18 and a plurality of (in this case six) side pincers 20 arranged in two sets, each of three, at opposite sides of the shoe support means, as will be hereinafter described in detail. The pincers are arranged in a generally U-shape about the shoe support means for gripping lasting marginal portions of the shoe upper and tensioning the upper about its last. Furthermore, the machine also comprises a wiper assembly (not shown) by which lasting marginal portions of the upper tensioned as aforesaid are wiped over and pressed against corresponding marginal portions of the insole. The wiper assembly comprises two wiper plates disposed symmetrically at opposite side of the longitudinal centerline L of the operating locality of the machine. 
     The shoe support means and the wiper assembly are conventional in pulling over and lasting machines and will not be described in greater detail herein. 
     The pincer assembly 16 of the machine comprises a base plate 22 on which the toe pincer 18 is supported for heightwise movement whereby to tension, in a direction lengthwise of its last, a shoe upper gripped thereby. Also mounted on the base plate 22, for pivotal movement each about an axis 24 extending heightwise of the base plate, are two support plates 26. The axes 24 are arranged one at either side of the toe pincer 18 and pass through the jaws of the pincer 18 at the corners formed at opposite ends of the leading edge thereof (see FIG. 1). Mounted on each support plate 26 is one of the sets of side pincers 20, each pincer being supported by a block 28 clamped to its support plate 26 by a clamp screw 30, whereby upon release of the latter each pincer can be positioned relative to the support plate 26 and to its neighbouring side pincers 20. Such adjustment may be pivotal about the clamp screw 30 or lengthwise of the block 28 (by means of the slot 32 provided therein); however, as is conventional in pulling over and lasting machines, such adjustment of the pincers should be such that (as shown in FIG. 1) leading edges of the jaws thereof form a continuous line. Furthermore, desirably the leading edges of the pincers adjacent the toe pincer 18 should form a continuous line therewith such that the corner adjacent the toe pincer also lies on the axis 24 for its associated support plate 26. The side pincers are also mounted for heightwise movement to tension the upper about its last in a conventional manner. 
     Each support plate 26 is mounted for pivotal movement about its axis 24, thus to move its associated set of side pincers 20 thereabout. For moving the support plates 26 under control, linkages constituted by Bowden cables generally designated 34 are provided, one attached to each plate at a point 36 remote from the axis 24. The manner in which the Bowden cables are operated will be described in detail hereinafter. 
     The heel support 12 of the machine comprises a support bracket 36 supporting a housing 38 in which a V-block 40 is movable transversely of the longitudinal centerline L of the operating locality. For reducing friction which may inhibit such transverse movement, a row of ball bearings 42 is provided acting between a rearward face of the V-block 40 and an inner face of the housing 38. For centralising the V-block with the base of its V on the longitudinal centerline L, equalising springs 44 are provided in the housing and act on abutment surfaces provided on the V-block. 
     As can be seen from FIG. 1, when a shoe is supported with the longitudinal centerline of its toe end aligned with the longitudinal centerline L of the operating locality, the heel end is significantly offset from said centerline L. In order to provide proper support for the heel end and to hold it against the thrust of a toe band (not shown, but conventional in pulling over and lasting machines), the V-block can slide easily transversely to accommodate to the particular position of the heel end, without in any way applying transverse forces which would affect the orientation of the toe end of the shoe. It will also be appreciated that, with such a heel rest 12, it is unnecessary to pre-set end positions for accommodating left and right shoes. 
     With reference to FIG. 2, the machine in accordance with the invention also comprises drive means generally designated 40 operatively connected to each of the support plates 26 through the Bowden cables 34. The drive means 40 is mounted at a location remote from the operating locality of the machine, this remote mounting being facilitated by the use of the Bowden cables 34. More particularly the drive means is mounted on a bracket 42 secured to a frame portion of the machine, the bracket supporting a support strap 44 on which a cross-bar 46 is carried which supports the sheath ends of the Bowden cables 34. Also mounted on the bracket 42 is a first piston-and-cylinder arrangement 48 having a piston rod 50 which is connected to a piston of a further piston-and-cylinder arrangement 52. The further arrangement 52 in turn supports a yoke constituted by a cross-member 54&#39; which is mounted for pivotal movement about a pin 58 secured in a lug 60 at the end of the piston-and-cylinder arrangement 52 remote from the piston rod 50. The Bowden cables 34 are again secured to the cross-member 54&#39;, the connections therebetween being spaced equidistantly from the pivot 58. 
     In the operation of the drive means 40, actuation of the piston-and-cylinder arrangement 48 is effective to move the piston-and-cylinder arrangement 52 bodily and the cross-member 54&#39; therewith, thus through the Bowden cables 34 moving also the support plates 26. Similarly, actuation of piston-and-cylinder arrangement 52 serves also to move the cross-member 54&#39; and the support plates 26 therewith. By using two piston-and-cylinder arrangements 48,52 which are of different dimensions, and thus of different stroke, it is possible using this tandem arrangement to achieve four separate pre-set positions of the cross-member 54&#39;, and thus of the support plates 26. It will be appreciated that, since the ends of the cross-member 54&#39; are moved equidistantly, the support plates 26, through the Bowden cables 34, are moved through equal distances also. Furthermore, the connection through the Bowden cables between the cross-member 54&#39; and the support plates 26 is such that the latter move in opposite directions, i.e. towards or away from each other. Thus, the support plates 26, and also the sets of side pincers 20 supported thereby, can be positioned in one of four pre-set positions corresponding to the four positions of the drive means 40. Adjustment of the support plates 26 towards and away from each other, it will be appreciated, serves to fit the side pincers 20 to shoes of different sizes. 
     It has been found that four pre-set positions are sufficient to accommodate adequately the types of shoe produced in one shoe factory. 
     It will be seen from FIG. 1 that when a shoe is positioned with its longitudinal centerline aligned with the longitudinal centerline L of the operating locality of the machine, the periphery of the shoe bottom along the &#34;inside&#34; edge is spaced further from the leading edges of the pincers 20 than the periphery of the &#34;outside&#34; of the shoe bottom. In order to militate against the offset relationship in the machine in accordance with the invention there is provided in combination with the drive means 40 also pincer orienting means generally designated 56. It will be recalled that the cross-member 54&#39; is mounted for pivotal movement about the pivot 58. In this manner, through the Bowden cables 34 the support plates 26 can again be moved equidistantly, but this time in opposite directions, so that they are now moved both in the same direction about their pivots 24, thus to accommodate to left and right shoes by moving the side pincers 20 into a desired orientation in relation to the shoe support means. 
     For so pivoting the cross-member 54&#39; the pincer orienting means 56 also comprises a piston-and-cylinder arrangement 62, a piston rod 64 of which is connected to one, extended, end of the cross-member 54&#39;. The piston-and-cylinder arrangement 62 is carried by a bracket 66 which is secured to the outside housing forming part of the piston-and-cylinder arrangement 52 so that as that cylinder is moved, whether in response to its own actuation or actuation of piston-and-cylinder arrangement 48, not only is the pivot point 58 moved, thereby moving the cross-member 54&#39; in a direction generally lengthwise of the support strap 44, but also the piston-and-cylinder arrangement 62 is moved therewith, so that relative movement between the cross-member 54 and arrangement 62 is avoided during such lengthwise movement. 
     It will thus be appreciated that, in using the machine in accordance with the invention, the sets of side pincers 20 can be set according to whether the shoe is a left or a right, and further this setting is not affected by, nor does it affect, movement of the support plates 26 to one of the four pre-set positions under the operation of the drive means 40. (In the drawings the sets of side pincers 20 and the cross-member 54&#39; are shown in a middle position. In operation, the cross-member 54&#39; will be pivoted about the pivot 58 in one or other direction, with consequent orientation of the sets of side pincers 20 about their respective axes 24 to bring the leading edges of the side pincers 20 into a balanced relationship with the periphery of the shoe bottom.) 
     For operating the piston-and-cylinder arrangement 62, thus to select the position of the side pincers 20 to accommodate to a left or right shoe, any suitable signal may be provided. Thus, as is conventional in pulling over and lasting machines, alternately signalling &#34;left&#34; and &#34;right&#34; may be provided, or alternatively the operator may select by manual switching a &#34;left&#34; or &#34;right&#34; operation. More sophisticated signalling systems may of course be envisaged without going outside the scope of this invention. Similarly, any suitable system may be provided for selecting a pre-set position under the control of the drive means 40: thus, manual switching or push buttons recommend themselves, in combination with instructions which may be provided on the work card which traditionally accompanies a batch of shoes around the shoe factory. Of course, again more sophisticated signalling systems can be envisaged within the scope of the invention. 
     Whereas in the machine described above the drive means 40 and the pincer orienting means 56 comprise fluid pressure operated motors in the form of piston-and-cylinder arrangements 48,52 and 62, other types of motor may be used, or indeed manual switching may be provided, without going outside the scope of this invention. 
     Furthermore, whereas in the machine described above two axes 24 are provided, one for each support plate 26, a single axis would be provided in other machines in accordance with the invention, said single axis supporting both support plates and being aligned centrally of the toe pincer arrangement.