PROGRESSIVELY ROUGHING MARGINAL PORTIONS OF A SHOE BOTTOM

PROGRESSIVELY ROUGHING MARGINAL PORTIONS OF A SHOE BOTTOM

TECHNICAL FIELD This invention is concerned with improvements in or relating to a method of progressively roughing marginal portions of a shoe bottom using a rotary radial roughing brush and also in or relating to machines for carrying out such a method.

BACKGROUND ART There is described in FR-A-2 529 763 an automatic shoe bottom roughing machine comprising a shoe support for supporting a lasted shoe with marginal portions of the bottom thereof to be roughed exposed, tool supporting means for supporting a rotary radial roughing brush, first, second and third drive means for effecting relative movement between the shoe support and tool supporting means, in directions extending respectively lengthwise, widthwise and heightwise of the bottom of the shoe to be roughed whereby the brush supported by the tool supporting means is caused to operate progressively along the marginal portions of the shoe bottom, and means for effecting rotation of the brush, wherein the tool supporting means supports the brush for swivelling movement about an axis of swivel extending heightwise of the shoe bottom in a fixed angular relationship with the direction of relative lengthwise movement between the shoe support and the tool supporting means, fourth drive means being provided for effecting such swivel movement.

In using the aforementioned machine, in carrying out a roughing operation on marginal portions of the bottom of a shoe supported by the shoe support the first, second and third drive means are controlled by means of an optical reader which follows the profile of a reference template corresponding to the profile of the shoe bottom to be roughed. The operation of the fourth drive means is controlled in such a manner that thebrushes remain constantly perpendicular to the edge of the shoe last, the control of the angular position of the roughing brush being effected by a position-sensing block by which signals are transmitted to the fourth drive means.

In the aforementioned machine the axis of swivel extends vertically of the direction of relative lengthwise movement between the shoe support and the tool supporting means so that, especially in the case of a high-heeled shoe, the brush, in being maintained perpendicular to the shoe bottom edge, is presented at a significant angle to the shoe bottom, especially in the waist region of the shoe bottom. As a result, the full width of the operating surface portion of the brush may not contact the shoe bottom, or it will be necessary to apply relatively heavy roughing pressure in order to deform the brush thus to achieve contact between it over its full width and the shoe bottom. in another machine, described in

EP-A-0 042 672, the radial roughing brush is mounted on a sub-frame, forming part of the tool supporting means, which is mounted for pivotal movement about an axis extending transversely of the shoe bottom such that the plane in which the operating surface portion of the brush lies is maintained normal, or substantially normal, to the marginal portion of the shoe bottom being roughed thereby. The provision of means for effecting such "tilting" movement of the brush does of course involve a more complicated structure, in so far as a pivotal sub- frame has to be provided, together with an extra motor, so that the cost of such a machine is increased. On the other hand, because the brush is not mounted for swivelling movement in this case, again it does not always accommodate to the shoe bottom contour which. especially in the joint region of a high-heeled shoe, is relatively complicated.

OBJECTS OF THE INVENTION It is thus one of the various objects of the present invention to provide an improved method of progressively roughing marginal portions of a shoe bottom using a rotary radial roughing brush, in carrying out which method the shoe bottom contour can be accommodated, with the operating surface portion of the brush maintained in contact with the shoe bottom over its width without the need for tilting the brush to maintain it perpendicular, or substantially perpendicular, to the shoe edge in the region of the shoe bottom marginal portion being roughed. it is another of the various objects of the present invention to provide an improved machine for carrying out a progressive roughing operation along marginal portions of a shoe bottom, using a rotary radial roughing brush, wherein the brush is mounted for swivel movement but not for tilting movement, and wherein the brush can be guided so as to maintain the operating surface portion thereof, over its width, in contact with the shOe bottom throughout the roughing operation without the application of undue pressure. DISCLOSURE OF THE INVENTION

The invention thus provides, in one of its several aspects, a method of progressively roughing marginal portions of a shoe bottom using a rotary radial roughing brush, characterised in that at least along the inside waist region of such shoe bottom at the heelward side of the joint thereof a longitudinal centre line of the region of contact between the operating (i.e. shoe bottom-contacting) surface portion of the brush and the shoe bottom marginal portion being roughed subtends an acute angle with the perpendicular to the tangent to the shoe edge for each position of such contact, and in that the region of contact is located on the joint-ward side of the perpendicular.

It will of course be appreciated that a major problem in achieving the object lies along the inside waist region of the shoe bottom at the heelward side of the joint thereof, especially in the case of a high- heeled shoe, where the contour of the shoe bottom is particularly complicated. It has been found that, by arranging the brush in the aforementioned angular disposition in relation to the perpendicular to the shoe edge, the area of contact between the operating surface portion of the brush and the shoe bottom marginal portion being roughed is significantly enhanced. In practice, moreover, it has been found that the steeper the spring of the shoe (i.e. the pitch angle of the waist region in relation to the forepart region), the greater the angle required, especially along the inside waist immediately adjacent the joint region of the shoe bottom. Whereas the invention is particularly concerned, in its broadest aspects, with the inside waist region, nevertheless it has been found advantageous also to maintain such an angular disposition between the said perpendicular and the said region of contact in other regions also of the shoe bottom to be roughed.

Thus the invention further provides, in another of its several aspects, a method of progressively roughing marginal portions of a shoe bottom using a rotary radial roughing brush, characterised in that at least in the regions of such shoe bottom immediately "downstream" and "upstream" of the joint of the shoe bottom a longitudinal centre line of the region of contact between the operating (i.e. shoe bottom- contacting) surface portion of the brush and the shoe bottom marginal portion being roughed subtends an acute angle with the perpendicular to the tangent to the shoe edge for each position of such contact, and in that both downstream and upstream of the joint region the region of contact is located on the joint-ward side of the perpendicular, said longitudinal centre line passing through the perpendicular as the roughing operation progresses from the downstream to the upstream region and vice versa.

More particularly, preferably said longitudinal centre line subtends an acute angle with said perpendicular along the whole of the side portions of the shoe bottom in the heel seat and waist regions thereof, with the longitudinal centre line located at the joint- ward side of the perpendicular. In such a case, moreover, bearing in mind that the brush must pass through a position of coincidence between the longitudinal centre line and the perpendicular at some stage, preferably said centre line lies coincident with the perpendicular during the roughing of the shoe bottom in the backseam region thereof.

Similarly, desirably said longitudinal centre line subtends an acute angle with said perpendicular along the whole of the side portions of the shoe bottom in the forepart region thereof, with the longitudinal centre line located at the joint-ward side of the perpendicular. In such a case, moreover, the longitudinal centre line passes through the perpendicular during the roughing of the marginal portion of the shoe bottom in the toe end region thereof. it will thus be appreciated that it has been found advantageous essentially to maintain the longitudinal centre line at an. acute angle to the perpendicular at all stages around the shoe bottom. The overall result of such an arrangement is that the longitudinal centre line is always directed more or less towards the joint region. As already mentioned, furthermore, the more steeply contoured the shoe bottom in a longitudinal direction, the greater the acute angle.

It has been found that, by selecting the desired angle of swivel of the brush, throughout the roughing operation the operating surface portion of the brush maintains a line contact with the shoe bottom marginal portion being roughed across the width of the marginal portion and over substantially the whole of the width of the operating surface portion of the brush, regardless of the lengthwise and widthwise contour of the shoe bottom without the application of undue pressure.

Whereas, whether empirically or mathematically, it may be possible to determine the angle of swivel for each point of the path of relative movement between the roughing brush and the shoe bottom marginal portions, it has been found to be relatively simple, in the case of a machine for use in carrying out a progressive roughing operation along marginal portions of shoe bottoms, to utilise the machine for an initial determination of both the path of the brush and also its angle of swivel. To this end, therefore, the invention further provides, in another of its several aspects, a machine for use in carrying out a method as referred to above, said machine comprising a shoe support for supporting a lasted shoe with marginal portions of the bottom thereof to be roughed exposed, tool supporting means for supporting a rotary radial roughing brush, first, second and, third drive means operable in accordance with a programmed instruction for effecting relative movement between the shoe support and tool supporting means, in directions extending respectively lengthwise, widthwise and heightwise of the bottom of the shoe to be roughed whereby the brush supported by the tool supporting means is caused to operate progressively along the marginal portions of the shoe bottom, and means for effecting rotation of the brush, wherein the tool supporting means supports the brush for swivelling movement about an axis of swivel extending heightwise of the shoe bottom in a fixed angular relationship with the direction of relative lengthwise movement between the shoe support and the tool supporting means, fourth drive means being provided for effecting such swivel movement, said machine having an operating mode, in which a roughing operation can be performed progressively along marginal portions of the shoe bottom, and a path-determining mode in which, with the brush supported by the tool supporting means, under operator control a path to be followed by the brush can be determined by positioning the brush sequentially at a succession of points along the marginal portions of the shoe bottom and storing the co-ordinates, along three co¬ ordinate axes, of each such point, and characterised in that the machine further comprises operator-actuatable control means for positioning the brush as aforesaid, said means also comprising means for causing the brush to swivel about the axis of swivel under operator control, together with means for causing the co-ordinates of each point together with data relating to the swivel position of the brush to be stored for each point. By thus enabling in-machine digitising to take place, the operator can satisfy himself, while digitising a model shoe, as to the optimum angle of swivel of the brush for any given position and the "swivel" information is then stored together with the three-axis information to form a pattern data file for subsequent recall.

The axis of swivel of the roughing brush is maintained in the aforementioned fixed angular relationship, regardless of widthwise and heightwise movement, in that the tool supporting means comprises a first parallel linkage arrangement through which movement of the tool widthwise relative to the shoe support can be effected by the second drive means and a second parallel linkage arrangement through which movement of the tool heightwise relative to the shoe support can be effected by the third drive means, said arrangements supporting a tool support member by which the tool is supported for swivelling movement about the axis of swivel. As in the case of the machine disclosed in FR-A-2 529 763, moreover, preferably the axis of swivel extends perpendicularly to the direction of lengthwise relative movement between the shoe support and the tool supporting means.

There now follows a detailed description, to be read with reference to the accompanying drawings, of one method of progressively roughing marginal portions of a shoe bottom using a rotary radial roughing brush and of one machine for use in carrying such a method, this method and this machine having been selected for description merely by way of non-limiting example of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:-

Fig. 1 is a side view of the machine in accordance with the invention; Fig. 2 is a plan view of the machine of Fig. 1;

Fig. 3 is a section view taken on the line III- III of Fig. 1, showing various motors and other features of drive means of the machine;

Fig. 4 is a fragmentary front view of the machine, showing details of a rotary roughing brush and its mounting;

Fig. 5 is a fragmentary side view of a rearward end of the shoe support, showing details of tool datum setting means; and Fig. 6 is a diagrammatic view of a shoe bottom. showing the angle of presentation (angle of swivel) of the operating surface portion of the roughing brush in relation to a perpendicular to the tangent to the shoe edge for various positions of the brush. BEST NODE FOR CARRYING OUT THE INVENTION

In carrying out the method in accordance with the invention (hereinafter "the illustrative method"), a shoe S, supported bottom uppermost with marginal portions of the bottom thereof exposed, is presented to a rotary radial roughing brush which is then caused to operate progressively along the shoe bottom marginal portions either by moving the shoe relative to the brush or the brush relative to the shoe. As can be seen in Fig. 6, for a succession of positions of the operating surface portion of the brush in relation to the shoe bottom marginal portions, and also in relation to the normal, or perpendicular (N1,N2...N28) , to the tangent to the shoe edge at the point of intersection of each of the brush positions with the shoe edge, the longitudinal centre lines (P1,P2...P28) of each area of contact between the brush and the shoe bottom are indicated. Although a succession of individual positions (which can be digitised, as will be referred to in more detail later) are thus indicated, in carrying out the roughing operation, it will be appreciated, the contact between the operating surface portion of the brush and the shoe bottom marginal portions is continuous, the brush passing through each of the positions marked in turn. To this end, the successive positions along the path of the brush and its angle of swivel are digitised and in addition an interpolation programme is provided for "merging" the individually digitised positions and swivel angles into a continuous path.

Viewing Fig. 6, it will be seen that except in four positions, two (Pjl,Pj2) in the joint region of the shoe bottom, one (Ph) in the backseam region and one (Pt) in the toe end region, said positions being indicated in chain-dot line, for any given position of the operating surface portion of the brush in relation to the shoe bottom marginal portions, the longitudinal centre line (P1,P2...P28) of the area of contact subtends an acute angle with, and at the joint-ward side of, the perpendicular (N1,N2...N28) to the tangent to the shoe edge (shown in chain-dot line) at such position. The overall effect, moreover, as can be seen in Fig. 6, is that the angle of presentation of the operating surface portion of the brush is at all times directed towards a central point of the joint region of the shoe bottom.

The advantages of such an arrangement can be enumerated as follows:

- the operating surface portion of the brush can be maintained in contact over its whole width with the shoe bottom marginal portion more reliably, without the need for excessive deforming pressure being applied; - it has always been considered desirable that the direction of rotation of the brush effects an inwiping movement over the marginal portion of the shoe bottom being roughed and in the past it has been considered desirable that this direction should lie perpendicular to the tangent to the shoe edge. By angling the brush as referred to above, however, it has now been found that the direction in which the material of the lasting marginal portions of the shoe bottom is urged during various lasting operations is more closely followed. This is particularly the case where the side portions of the shoe have been lasted using so-called sleeking rollers, e.g. as described in EP-A-0 511 810; the brush is less likely to engage any metallic shank Sh located in the waist region of the shoe bottom. Moreover, since any such engagement is at an angle, it is less likely to be detrimental whether to the roughing brush or to the shank itself.

In carrying out the illustrative method, the operating surface portion of the brush is first brought into engagement with the marginal portion of the shoe bottom at PI in the region of the heel breast line, at the inside waist of the shoe, and the roughing operation then takes place progressively towards the joint region with the region of contact maintained at an acute angle to the perpendicular (N1,N2...N28) to the tangent to the shoe edge during such operation. It has been found that the steeper the spring of the last (i.e. the pitch of the waist region in relation to the forepart region), the greater the sub-tended angle of presentation should be. In the region of the joint itself, the brush must be swivelled through a significant angle over a relatively short distance; this can clearly be seen in Fig. 6. By this relatively sharp swivelling action, first the relatively complicated contour of the shoe bottom in the joint region (especially of a high-heeled shoe) can be accommodated while at the same time the brush angle is "prepared" for the continuing operation downstream of the joint region towards the toe end region of the shoe. At the toe end region the longitudinal centre line Pt of the region of contact momentarily will lie coincident with the perpendicular to the tangent to the shoe edge; this is particularly true of a pointed toe, as shown in Fig. 6, but is also true of round and indeed square toes, since rarely is the shoe bottom flat, and consequently rarely will the coincidence of the longitudinal centre line and the perpendicular be the optimum position for the line of contact of the operating surface portion of the roughing brush with the marginal portion of the shoe bottom. When the brush now approaches the joint region along the outside waist of the shoe, there is less need for a severe swivelling action, even in the case of high- heeled shoes, but rather there is a gradual swivel over a somewhat larger area than in the case of the inside waist, so that the longitudinal centre line remains directed towards the central part of the joint region. The brush then operates progressively from the joint region of the outside waist heelwardly, the longitudinal centre line Ph lying coincident with the perpendicular momentarily at the backseam region, whereafter the brush proceeds to the finishing position, which may slightly overlap the start position.

The machine now to be described (hereinafter called "the illustrative machine") comprises a shoe support generally designated 10 and tool supporting means generally designated 12, the shoe support being mounted for rectilinear movement, in a direction extending lengthwise of the bottom of a shoe supported thereby, in a frame 14 of the machine, and the tool supporting means being carried on said frame, as will be hereinafter described.

The shoe support 10 of the illustrative machine is generally similar to the shoe support described in GB-A-2,077,090 and is thus arranged to support a shoe, bottom up, with marginal portions of the shoe bottom to e operated upon exposed. In the illustrative machine the shoe support 10 is mounted for sliding movement, along a rectilinear path, along two shafts 16 supported by the frame 14. More particularly, a frame 18 of the shoe support is mounted on blocks 20 for such sliding movement. The left-hand block 16 (viewing Fig. 3), moreover, has depending therefrom a clamp 22 which clampingly engages a belt 24 entrained about two pulleys 26, at opposite ends of the path of travel of the shoe support 10. A forward (i.e. right-hand viewing Fig. 1) one of the pulleys 26 is driven by a belt 28 which is entrained about a drive pulley 30 supported on an output shaft 32 of a stepping motor 34 mounted on the machine frame 14. The stepping motor 34 constitutes first drive means of the illustrative machine, for effecting movement of the shoe support 10 relative to the tool supporting means 12 in a direction extending lengthwise of the bottom of a shoe supported by the shoe support.

The tool supporting means 12 comprises a base 40 which is fixedly mounted on a frame 14. Upstanding from the base 40, moreover, are two support members 42, arranged one at each side of the path of movement of the shoe support. Mounted at 54 for pivotal movement on and extending between the support members 42 is a cross- member 44 at each end of which, adjacent the appropriate support member 42, a forwardly extending arm 46 is mounted at 52 for pivotal movement in a direction extending widthwise of the path of movement of the shoe support 10. Interconnecting the forward ends of the two arms 46, furthermore, by ball joints 48 is a tool support member 50, in the form of a casting having a generally planar top surface. The cross-member 44, arms 46 and tool upport member 50 constitute a first parallel linkage arrangement of the illustrative machine, facilitating movement of the tool support member 50 in a direction extending widthwise of the path of movement of the shoe support 10, and thus of the bottom of a shoe supported thereby.

At the base of each support member 42, and extending inwardly therefrom, is a flange 56 on which is supported, by means of a ball joint a rearward end of a second forwardly extending arm 58; each arm 58 extends parallel to its associated arm 46, and the forward end of each of the arms 56 is connected, again by ball joint, to a depending lug portion 60 on the tool support member 50. Each support member 42, together with the arms 46, 58 and depending lug portion 60 thus constitutes a set of parallel linkages for supporting the tool support plate 50, the two sets (i.e. one on each side of the tool support member 50) constituting a second parallel linkage arrangement of the illustrative machine whereby heightwise movement of the tool support member 50 can be effected relative to the path movement of the shoe support 10, and thus of the bottom of a shoe supported thereby. For effecting widthwise movement of the tool support member 50 relative to the shoe support 10 the illustrative machine comprises a stepping motor 66, constituting second drive means of the illustrative machine, said motor being mounted between two brackets 68 secured to the cross-member 44. On the output shaft of the motor 66 is a nut (not shown) captive in a housing 70 secured to a rearward portion of the left-hand (viewing Fig. 3) arm 46 by means of a pin 72. The nut engages with a ball screw 74 whereby rotation of the output shaft is effective to pivot the arm 46, and thus the first parallel linkage arrangement, about the pivot 52 by which the arms 46 are secured to the cross-member 44. On an end of the ball screw, moreover, is mounted a sleeve 76, an end portion of which describes a spiral. This sleeve cooperates with a proximity switch 78 and serves as a homing device whereby, in a setting-up operation of the machine, the first parallel linkage arrangement is centralised by operation of the motor 66 to bring the sleeve 76 to a desired position in relation to the proximity switch 78.

Mounted on the base 40 of the tool supporting means 12 is a further stepping, motor 84 (constituting third drive means of the illustrative machine) by which the cross-member 44 is caused to pivot about the pivots 54 by which it is mounted on the support arms 42, whereby through the second linkage arrangement to effect heightwise movement of the tool support member 50 in relation to the shoe support 10. To this end, an output shaft of the motor 84 is constituted by a ball screw 86 with which a nut (not shown) engages, the nut being housed captive in housing 88 secured between two brackets 90 extending forwardly of the cross-member 44. Rotation of the motor 84 is thus effective to move the housing 88 heightwise, thus to pivot the cross-member. As in the case of the second drive means, moreover, at the end of the ball screw 86 is arranged a sleeve 92 having a spiral end, said sleeve cooperating with a proximity switch 94 whereby, in a setting-up operation, to return the second parallel linkage to a "home" position. in order to counterbalance the weight carried by the arms 46 and support member 50, compensating springs 98 are secured to further brackets 100 carried on the cross-member and also to the base 40 of the tool supporting means 12. Mounted on the tool support member 50 of the illustrative machine is a rotary roughing tool 698 in the form of a radial wire brush, tool driving means being provided for effecting rotation of the brush as will now be described. The tool driving means of the illustrative machine comprises a motor 110 which is carried by a motor support member 112 which is pivotally mounted on a rod 114 supported at opposite ends on brackets 116 carried on the left-hand (viewing Fig. 3) flange 56 of the support member 42. The motor is thus capable of heightwise pivotal movement about the axis of the shaft 114. A rearwardly extending output shaft of the motor 110 carries a toothed drive pulley 120 about which a continuous belt 122 is entrained. It will thus be appreciated that the motor support member 112, and thus the motor 110 itself, is held suspended through the pulley 120 for pivotal movement about the axis of the rod 114; this thus maintains the drive belt 122 in tension. In order to damp any tendency of the motor and its support member to "bounce", moreover, and in order to maintain a constant tension in the belt 122, a piston- and-cylinder arrangement 118 is mounted on the cross- member 44 and acts on the member 112 to apply a constant downward pressure thereto.

Mounted, above the drive pulley 120, on a rear portion of the cross-member 44 and centrally thereof are two further pulleys 124 over which the "downstream" and "upstream" portions of the belt 122 are entrained. Each further pulley 124 is mounted such that a tangent to the drive surface thereof coincides with a tangent to the drive surface of the drive pulley 120. It will be appreciated that, as the tool support member 50 is moved heightwise, a foreshortening effect of the further pulleys 124 will take place, because they are located behind the pivots 54. In order to accommodate for any such lengthwise variation in the position of the belt- engaging surface thereof in relation to the drive pulley 120, the latter is wide in relation to the width of the belt to accommodate for any lengthwise movement of the belt over its surface in response to any corresponding movement of the further pulleys 124.

For accommodating widthwise movement of the tool support member 50, furthermore, each of the further pulleys 124 are each mounted on a bracket 126, and each bracket is mounted, independently of the other, for pivotal movement about a pivot 128 carried on a flange formed on the rear of the cross-member 44. The two further pulleys 124 thus constitute belt-aligning means of the tool driving means. Pivotal movement of the brackets 126, furthermore, is effected in a self- compensating manner according to the direction in which the reaches of the belt 122 extend towards the tool support member 50, as it is moved widthwise of the path of the shoe support 10.

The mounting of the tool 696 and the manner in which it is connected, via the belt 122, to the motor 110 will now be described with reference to Fig. 4. Mounted on the tool support member 50 is a bearing block 672 within which is accommodated, for rotation relative thereto, a hollow shaft 674 carrying pulleys 676, 678 at its top and bottom. The hollow shaft 674 itself also provides a bearing for a further shaft 680 which carries at its lower end a tool carrier 682 in the form of a metal block having generally the shape of an inverted L. The tool carrier 682 can pivot about the axis of the shaft 680, as will be described hereinafter. Mounted on a pivot 694 at a lower end of the tool carrier 682 is a lever 692 which supports at its remote end a tool supporting shaft 696 on which the roughing tool 698 is mounted for rotation. For effecting rotation of the brush 698 a pulley 700 is mounted on the shaft 696 and connected by a timing belt 702 to a further pulley 704 mounted for rotation about the axis of the pivot 694. The pulley 704 is a double pulley and a further timing belt 708 passes thereover and over two angled pulleys 710, 712 and finally about the lower pulley 678 on the shaft 674. The belt 122 driven by the motor 110 is entrained about the upper pulley 676 so that operation of the motor, in the operation of the illustrative machine, is effective, through the various pulleys and belts, to cause the tool 698 to be rotated about the axis of the shaft 686, thus to present a rotating operating surface portion to the bottom of a shoe supported by the shoe support 10.

Referring to Fig. 2, belt-aligning means is also provided adjacent the pulley 676 in order to accommodate to widthwise movement of the tool support member 50, said belt-aligning means comprising two rollers 130 rotatable about a common axis, the rollers having smooth surfaces which run on the back of the timing belt 122. The rollers 130 are mounted on a common bracket 132 which is mounted for pivotal movement about a pin 134 carried by the tool support member 50. The rollers 130 serve to hold the forward end of the belt in alignment with the pulley 676 and are sufficiently wide to ensure that the belt is constantly in engagement therewith, regardless of the widthwise movement of the tool support member. Maintaining the belt in the same plane as the pulley 676 also maintains the belt aligned regardless of the heightwise position of the tool support member. In the case of the front belt-aligning means it has been found desirable positively to cause pivotal movement of the rollers to take place about the pivot 134 as widthwise movement of the tool support member 50 takes place and to this end a link 136 is pivotally connected at one end to the bracket 132 and at the other to a forward portion of the left-hand (viewing Fig. 3) arm 46. Thus, as the arm 46 pivots, the bracket 132 and thus the rollers 130 are pivoted also.

As already mentioned above, the tool carrier 682 is mounted for pivotal movement about the axis of the shaft 680 (Fig. 4), and indeed the tool is thus mounted for swivelling movement about said axis. To this end a pulley 684 is mounted at the upper end of the shaft 680 and is connected by a timing belt 686 to a further pulley (not shown) supported on a stub shaft 140 on the tool support member 50. Also mounted on the stub shaft is a further pulley 142 connected by a timing belt 144 to a drive pulley 146 on the output shaft of a further stepping motor 148. This latter motor, which constitutes fourth driving means of the illustrative machine, is also carried by the tool support member 50. (The various belts in this drive sequence are all timing belts and the pulleys timing pulleys. ) It will thus be appreciated that by operation of the motor 148 the tool carrier 682, and thus the tool 698 supported thereby, can be rotated about the axis of the shaft 680. In this way, the plane of the roughing brush can be maintained at a desired angle to the marginal portion of the shoe bottom being operated upon at any given time. From time to time it is desirable to bring the roughing brush 698 to a desired heightwise relationship with the shoe bottom. For example, when the illustrative machine is in use and the brush is operating upon marginal portions of the bottoms of a succession of shoes presented thereto, the bristles tend to wear and indeed the sharpness of the bristles at the operating surface of the tool deteriorates by contact with the shoes so that re-grinding is necessitated from time to time, which again leads to a shortening of the bristles, with the effect that the overall diameter of the brush decreases in use. In order to accommodate the reduction in brush diameter (and this is illustrated in Fig. 4 by showing a brush in its original diameter (in chain-dot line) and in its reduced diameter (in full line)), use is made of the fourth drive means in the manner now to be described. In addition, bearing in mind that shoe bottoms may exhibit irregularities from time to time and indeed a given shoe bottom, though nominally the same as the shoe bottom which has been previously digitised, may in fact be different from it, the rotary brush is mounted on the tool carrier for limited heightwise movement, as will also now be hereinafter described.

For setting limits to the heightwise movement of the tool mounting, and indeed for varying the heightwise position of those limits according to e.g. the diameter of the brush, setting means is provided comprising a further shaft 716 accommodated within the shaft 680, which is hollow for the purpose. The shaft 716, which in the normal operation of the machine thus rotates with the shaft 680, carries at its lower end a block 718 supporting an abutment pin 720. The pin 720 projects from the block 718 and is accommodated in a slot 722 formed at the upper end of a link 724 pivotally carried at its lower end on the tool mounting 692. The slot 722 thus determines the limits of pivotal movement of the lever 692 and thus of the heightwise position of the brush 698 in relation to the pin 720, and thus to the tool carrier 682. It will of course be appreciated that, when the machine is in a rest condition, the link 724 will rest with the upper end of its slot abutting the pin 720, thereby determining the lowermost position of the brush, and in the operation of the machine, when the brush is operating on a shoe bottom, it will be able to "float" relative to the tool carrier 682 within the confines of the slot 722.

The tool mounting 692 is urged downwards by a pneumatic cylinder 730 which is mounted on the tool carrier 682 and a piston rod of which is pivotally connected to a block 732 secured to the tool mounting 692. The cylinder 730 also is effective to apply a predetermined pressure to the mounting 692, and thus to the tool 698. For limiting "bounce" of the brush, furthermore, a damper arrangement 734 is also supported by the tool carrier 682 and acts against the block 732. For providing air to the cylinder 730, if desired the shaft 716 may also be hollow, carrying at its upper end and also at or adjacent its lower end suitable rotary couplings (only the upper one (736) of which is shown in Fig. 4) , for connection by pipelines (not shown) , respectively to a source of air under pressure and to the cylinder 730. Alternatively, the connection to the cylinder 730 from the air source may be direct.

At its upper end the shaft 716 is threaded with a thread of relatively large pitch. This threaded portion carries a nut which is accommodated within the housing 688 and is provided with a hardened sleeve 742. In the normal operation of the machine the nut rotates with the shaft 716 and thus with the shaft 680, but it is capable of being locked against such rotation, as will now be described. The shank of the nut and the sleeve 742 project into a portion of the housing which is rotatably held by the bracket 690. That portion of the housing is cut away whereby, when the tool carrier is in a "park" position (described hereinafter), to allow access to the sleeve 742 by a plunger 744 actuated by a diaphragm cylinder 746 carried on the bracket 690. The effect of locking the nut 740 while the shaft 680 is being rotated together with the shaft 716 is thus to cause the shaft 716 to move heightwise relative to the nut 740 now locked against rotation, and in this way the heightwise position of the pin 720 is thus varied in relation to the tool carrier 682. This therefore has the effect of varying the heightwise position of the upper and lower limits of movement of the tool mounting 692, and thus of the brush 698, in relation to the tool carrier 682. Because the rotation of the shaft 680, furthermore, is under control of the stepping motor 148, it will be appreciated that the movement of the abutment pin 720 can thus be accurately controlled. From time to time, e.g. at the start of a working day, the heightwise position of the tool is established in the following manner: firstly the cylinder 746 is operated to lock the nut 740 against rotation and the drive motor for rotating the shaft 680 is then operated to cause the block 718, and thus the abutment pin 720 therewith, to be raised to an uppermost limit position which is determined by a proximity switch 750 carried on the bracket 690. The proximity switch senses the presence of a shoulder 752 on a block 754 carried on the upper end of the shaft 761. In this way, the "start" position of the tool is ascertained and can be stored in memory by the control means. When the uppermost position of the abutment 720 is known, it is then necessary to set the operating surface portion of the brush to a datum, according to the diameter of the brush, and to this end tool datum setting means is provided comprising a proximity switch 756 (Fig. 5) is provided at a right-hand (viewing Fig. 3) rearward end of the shoe support 10, into opposed relationship with which the brush is brought, by moving the tool support member 50 is moved widthwise of the shoe support 10, for a tool datum setting operation. For operating the proximity switch 756 a leaf spring 758 is provided which is engageable by the roughing brush to urge it downwards towards the proximity switch, said spring also having a downwardly facing lip 760 by which the proximity switch is actuated. In the operation of the illustrative machine, when a tool datum setting operation has been selected the stepping motor 66 is first operated to move the tool support member 50 widthwise to bring the tool into opposed relationship with the proximity switch 756, and thereafter the cylinder 746 is actuated to lock the nut 740 against rotation and the stepping motor 148 of the fourth drive means is then operated to effective rotation of the shaft 680 as described above, thus to effect downward movement of the tool. Such downward movement is of course discontinued, and the position of the tool thus set at its datum, upon operation of the proximity switch 756. During this operation, the pressure applied by the cylinder 730 is such that the link 724 is held with the upper end of its slot 722 in engagement with the abutment pin 720. It will be appreciated that, by counting the number of "steps" effected by the stepping motor 148 during this tool datum setting operation, the position of the brush is accurately determined and can be stored in the memory.

The shoe support 10 also supports, at a left- hand (viewing Fig. 5) rearward end, a grinding stone 766 into engagement with which the roughing brush 698 may be brought from time to time. In selecting a grinding operation the motor 66 of the second drive means is effective first to bring the brush into a desired opposed relationship with the grinding stone, whereafter the brush is then again lowered through a predetermined distance under the action of the motor 148 for rotating the shaft 680 and with the nut 740 locked against rotation as aforesaid, generally in the same manner as for a tool datum setting operation. For varying the heightwise position of the grinding stone from time to time as it becomes worn, the stone is mounted on a lever 768 supported by a pivot 770 on the shoe support 18. The end of the lever remote from the pivot is pivotally connected to one arm of a ball crank lever 772 itself also pivotally mounted on the shoe support. Operatively connected to the other arm is a manually operable adjustment screw 774, rotation of which thus effects, through the aforementioned linkage, heightwise movement of the stone 766.

In the operation of the illustrative machine, a shoe is first mounted in the shoe support 10, bottom uppermost, with the heel end of the shoe rearwardly (i.e. facing away from the operator), the shoe then being clamped both lengthwise and widthwise, and the heel end thereof being centralised, as described in detail in GB-A-2,077,090. At the same time the length of the shoe is "measured" and whether it is a left or a right is detected, again as described in the aforementioned GB specification. The illustrative machine is provided with a control panel generally designated 160 by which the operator can select a programmed instruction according to the style of shoe to be operated upon. With the style selected, the operator can initiate a cycle of operation of the machine and the roughing tool 698 is then caused to operate progressively around the marginal portion of the shoe bottom in order to rough it, the direction of rotation of the brush being such that it always "wipes" inwardly over the marginal portion of the shoe bottom being operated upon, and to this end the brush is caused to swivel about the axis 680 to maintain it in a desired angular relationship with the shoe bottom. The particular angle at which the brush is oriented in any particular position is again controlled by the programmed instruction, as is also the particular pressure applied at any particular position and indeed the speed of rotation of the brush, all of which are variable during the operating cycle.

For creating a programmed instruction, the machine has a path-determining mode in which the tool is moved under operator control to a succession of positions along the marginal portion of the shoe bottom and each position is then "taught" in terms of three coordinate axes (as described in detail in US-A-4,541,054), brush rotational speed and brush pressure (as described in detail in EP-A-0 511 814) and swivel angle (as will now be described) .

For effecting the path-determining operation, a succession of displays are exhibited on a display panel 162 of the control box 160, asking the operator in turn to indicate a value for each of the various settings; in addition cursor keys 164a,164b (which could otherwise be in the form of a joystick) are provided on the control box for effecting widthwise and heightwise movement of the tool under operator control, again as described in detail in US-A-4,541,054; these cursor and other keys are indicated generally at 164 in Fig. 2. In the case of setting the swivel angle, the operator utilises two directional keys 164c,164d according to the direction of rotation selected for re-orienting the brush about the axis of the shaft 680. When the various settings for the position of the brush lengthwise, widthwise and heightwise of the shoe bottom and also the swivel angle of the brush have been made, the operator merely operates a "teach" key 164e, whereupon the settings are stored and the shoe support drive motor 34 is then actuated to move the shoe to a next position, as described in the aforementioned US-A-4,541,054. When the tool has thus been caused to progress under operator control along the whole of the periphery of the shoe bottom and the settings have been stored for each point, in volatile memory, thus constituting a pattern data file for the shoe, and the file may, if desired, then be transferred to non-volatile memory for subsequent use as a programmed instruction for the particular style of shoe to which the file relates. When the shoe is thereafter selected for treatment, the file is also selected and the tool automatically follows the "taught" path, which is determined by the various "taught" points with an interpolated line therebetween; the angle of swivel of the tool is also determined by an interpolation between the "taught" angles of orientation. A grading programme may also be provided by which the data in the file, including the data relating to the angle of swivel, is modified according to the length of the shoe as measured by the shoe support 10, and in addition the "Y-axis" values and also the data relating to the angle of swivel may be reversed so that the same pattern data file can be used for left and right shoes.