PULLING OVER AND TOE LASTING MACHINE

Abstract: The pincers (22) of the machine are mounted each for limited pivotal movement about an axis (A) spaced from the edge of the last in such a manner that the pincers move from a loading position, spaced outwardly of a shoe supported by the shoe support (20) and above the plane of the wipers (28), inwardly and downwardly to a position in which they lie beneath the insole (I) of such shoe. During this movement, which is powered (60), a slipping grip is applied by the pincer jaws (66, 68) to the lasting marginal portions of the upper (U). Thereafter full pressure is applied to the pincer jaws, and the upper is first tensioned by relative heightwise movement between the shoe support (20) and the pincers (22) and then in-wiped by the wiper assembly (28), the grip of the upper by the pincers (22) being released in a desired sequence and in timed relation with the in-wiping movement of the wipers.

Description: PULLING OVER AND TOE LASTING MACHINE This invention is concerned with a pulling over and toe lasting machine comprising a shoe support for supporting a shoe comprising a shoe upper on a last and an insole on the last bottom, a plurality of pincers, including toe and forepart pincers, arranged about the shoe support, pincer-closing means for effecting the closure of each pincer thus to cause lasting marginal portions of the upper of a shoe supported by the shoe support to be gripped by the pincers, drive means for effecting relative movement, heightwise of the bottom o , a shoe supported by the shoe support, between the shoe support and the pincers, thus to tension a shoe upper gripped as aforesaid over its last, and a wiper assembly for engaging the lasting marginal portions of the shoe upper tensioned as aforesaid and for wiping said portions inwardly over and pressing them against corresponding marginal portions of the insole. in certain machines of the above type it has been proposed, in order to facilitate the insertion of the lasting marginal portions of a shoe upper into the pincers to locate the pincers initially above the wiping plane, i.e. the plane in which the wiper assembly moves as aforesaid. It is also often the case that, for effecting relative heightwise movement between the shoe support and the pincers, the shoe support is moved heightwise from a position below the wiping plane to a position in which the shoe bottom lies in said plane. Such relative heightwise movement between the shoe suport and the pincers customarily is in a direction perpendicular or substantially perpendicular to the shoe bottom. This means that not only must the pincers be so spaced about the shoe support during the loading of the shoe that the lasting marginal portions of the upper can be readily, inserted into the open jaws of the pincers by the operator but also such spacing of the - pincers is maintained - during the tensioning operation- In tensioning the upper, therefore, the tendency is that, the upper is spread outwards. In such a case, .it will be appreciated, the location of the upper on its last cannot." readily be observed by the operator at the end of the: relative heightwise movement between the shoe support and the pincers, at which stage the operator has the opportunity of adjusting the position of the upper on its last by discretionary pulling. This lack of observability may give rise to a problem of correctly locating the upper on its last, again especially in the case of uppers incorporating mudguards and uppers of the "apron front" type (where the relationship between the mudguard or seam, as the case may be, and the feather edge is important) and also in the case of under-cut lasts, i.e. lasts having an edge-chamfered bottom. It will of course be appreciated that the particular problems, referred to above, of lasting "mudguard" or "apron front" uppers serve only to highlight the fact that there are problems of distorting shoe uppers during pulling over, which problems are applicable to uppers of all types of construction. It is thus the object of the present invention to provide an improved pulling over and toe lasting machine in which the problems set out above, e.g. relating to the location of the upper on its last, upper distortion during pulling over and the transfer of control of the upper, are mitigated. This object is resolved, in accordance with the present invention, in a machine as set out in the first paragraph above, in that auxiliary drive means is provided whereby prior to the operation of the drive means each pincer is caused to move relative to the shoe support with a component of inward movement. Thus in using the machine in accordance with the invention the inward component of movement ensures that, rather than spreading the upper outwards in relation to the last, a wrapping action of the upper about the last can be achieved, thereby giving the operator the facility of observing the position of the upper in the feather edge region thereof, and thus facilitating the adjustment of its position. In addition, by drawing the upper more closely about the last while still being held by the pincers, any tendency (which may arise in the conventional machines referred to above) for the inwardly moving wiper assembly to cause over-tensioning of the still gripped upper as it is engaged by the wiper assembly is reduced, while at the same time the release of the upper by the pincers can be delayed until the wiper assembly is more closely adjacent the last, thereby enhancing the transfer of control of the upper from the pincers to the wiper assembly. What is more, the need for a slipping grip to be applied during such transfer of control, which is conventional in pulling over and toe lasting machines currently available, may be dispensed with, as is also any requirement, also often required in conventional machines, for frequent adjustment of the applied slipping grip pressure according to the various material characteristics encountered. Preferably the pincers are moved through a pre-set distance under the action of the auxiliary drive means. Moreover, in a machine wherein the drive means is effective to move the shoe support heightwise relative to the pincers through a pre-set distance to bring the bottom of a shoe supported by the shoe support into the plane of the wiper assembly, conveniently the auxiliary drive means is effective to move the pincers as aforesaid to bring them to a position in which they do not impede the operation of the wiper assembly (i..e. below the wiping plane) . Furthermore, by setting the amount of heightwise movement of the shoe support under the control of the drive means, viz. by setting the start position of the shoe support, the tensioning of the upper about its last can be closely controlled, without the complication of calculating also the amount of tensioning which will be effected either by the movement of the pincers to the position in which they do not impede the operation of the wiper assembly or by the inwiping movement of the wiper assembly. For effecting the inward movement of the pincers as aforesaid, preferably each pincer is mounted for pivotal movement about an axis, the arrangement being such that, with a shoe supported by the shoe support, said axis is spaced from the edge of the shoe by a distance only slightly greater than the distance between said axis and the end of the pincer. In this way, the end of the pincer, during such pivotal movement, passes close to the edge of the shoe, thereby enhancing the "wrapping" effect of the inward movement. Moreover, the pincer is preferably so positioned in relation to its pivotal axis that the component of inward movement is greater than that of movement heightwise of the shoe, thereby again serving to enhance the wrapping effect. Conveniently the auxiliary drive means is fluid pressure operated and comprises a plurality of piston-and- cylinder arrangements, one associated with each pincer. In this way, the movement of each pincer takes place independently of the others, although if desired initiated by the same signal. Furthermore, the pre-set distance may vary from pincer to pincer. In one embodiment, under the action of the pincer-closing means the pincers are caused to grip the shoe upper with a reduced pressure during the operation of the auxiliary drive means, and thus during the inward movement of the pincers, and thereafter with increased pressure. In this way the degree of tensioning of the upper can be more closely controlled and any tendency to over-stretch the upper can be mitigated while still allowing the desired amount of relative heightwise movement between the shoe support and the pincers to take place. Furthermore by the end of such relative heightwise movement, no significant amount of further tensioning of the upper will take place, other than that effected by the operator using the discretionary pull facility. Thus, the operator can be confident that once he is satisfied that the upper is correctly positioned on its last, there will be no significant amount of distortion of the upper during the subsequent lasting operation. By this combination of moving the pincers inwardly while gripping the upper with a slipping grip, as a preliminary step to the tensioning operation, a particularly advantageous effect can be achieved in terms of the easy insertion of the upper into the pincers, the reduced risk of danger to the operator (since the initial closing pressure is the reduced, slipping grip, pressure) , the enhanced control of the location of the upper on the last, the avoidance of distortion of the upper which could be detrimental in the finished shoe, and the effective control of the upper during transfer from the pincers to the wiper assembly. Preferably the reduced pressure is applied to the pincer-closing means by a spring arrangement, while the increased pressure is applied by fluid pressure operated means, said latter means also acting, against the spring arrangement, to open the pincers for the insertion of the lasting marginal portions of a shoe upper therein, and of course also for:the release of the upper, at a later stage in the operating cycle. There, now follows a .-detailed description, to be read with reference to the accompanying ; drawings- of one- machine ' in accordance with the invention. It will of, course be realised, that this machine has been selected for description merely by way of non-limiting example of: the invention. In the accompanying drawings.- Fig 1. is a perspective view of a pulling over and toe lasting machine in accordance with the invention; and Fig 2. is a fragmentary view, showing details of the mounting of one pincer of such machine, and its relationship with the shoe support thereof. The machine now to be described is a pulling over and toe lasting machine comprising a shoe support, in the form of a toe rest 20, and a plurality of pincers 22, comprising toe and forepart pincers, arranged in a generally U-shaped array about the shoe support. In addition, the machine comprises toe lasting instrumentalities including a wiper assembly comprising two wiper plates 28, a toe pad 32 and a toe band 34. A heel rest 36 is provided for holding the shoe in position on the toe rest 20, and also, for applying adhesive to the toe and forepart regions of the shoe bottom prior to the operation of the wiper assembly 28, a so-called imprinter plate 38 is provided, which extends about the periphery of the toe rest. The machine further comprises a foot switch FS, which is operator-actuated, and a control panel 26 is provided incorporating various switches for facilitating various settings of the machine. Machines of the aforementioned type are well known, as is also their operation. The pincers 22, which are mounted on a base plate 40 for adjustment, independently of one another, relative to the shoe support 20 according to the style of shoe being operated upon, are generally similar to one another; thus only one such pincer will now be described with reference to Fig. 2. For supporting the pincer a support 44 is adjustably supported by the base plate 40, a clamp bolt 42 being provided for clamping the support in adjusted position. Mounted in the support 44 is a column 46 which is movable heightwise by means of a piston-and-cylinder arrangement 48, mounted on the under-side of the base plate 40. Carried on- the column 46 is a block 50, the upper end of which is bifurcated to form two wall portions and a base portion providing an arcuate slide surface 52. Received between the wall portions is a pincer body 54 having a support surface 56 shaped complementarily to the slide surface 52. In this way, the pincer body 54 can slide along the surface 52, to an extent allowed by two pin-and-slot arrangements 58. For effecting such sliding movement of the pincer body 54, furthermore, a piston-and-cylinder arrangement 60 is pivotally supported by the block 50 and the piston rod 62 thereof is pivotally connected to a lug 64 formed on the pincer body. The piston-and-cylinder arrangement 60 thus constitutes auxiliary drive means of the machine. The pincer body 54 supports a fixed jaw 66, on which is pivotally mounted a movable jaw 68, whereby the lasting marginal portion of an upper U inserted between the jaws can be gripped. For closing the movable jaw 68 against the fixed jaw 66, a plunger 70 is provided, engageable with a rearward end of the movable jaw 68, said plunger 70 being formed integral with a piston 72 slidable in a cylindrical bore 74 formed in the pincer body 54. The plunger 70 has an internal bore extending lengthwise thereof in which is accommodated, one end of- a spring 76 the opposite end of which is accommodated in a sleeve 78 screwed into the floor of the bore . 74; the upper end of the sleeve 78, which is accommodated within the internal bore of the plunger 70, serves to guide the plunger and at the same time retain the spring. Under the influence of the spring 76, the plunger acts on the movable jaw 68 to close it. In the end of the sleeve 78 is t readedly arranged a plug 80 whereby the pressure applied by the spring 76 can be adjusted. The gripping pressure applied by the jaws 66, 68 under the influence of the spring 76 is relatively low, being sufficient to cause the upper U of a shoe supported by the shoe support 20 to be laid over its last L, when heightwise relative movement is effected between the shoe support 20 and the pincers 22, but not sufficient to effect any tensioning of the upper U. For applying an increased pressure to the jaws 66, 68, the lower end of the cylinder 74 is connected by a line LI to a source of air under pressure, through two pilot valves PV1, PV2. In the condition shown in Fig. 2, both valves are de-actuated, and thus in their "spring return" condition, whereby the lower end of the cylinder 74 is exhausted to atmosphere through valve PV1 and the upper end thereof through line L2 and the two valves PV1, PV2. When it is desired to apply heavy gripping pressure, both valves PV1, PV2 are switched, whereupon air under pressure passes therethrough to the lower end of the cylinder. This arrangement also enables the valves to be opened, whether for release of the upper U or for enabling the lasted marginal portions of the upper to be inserted in the pincers 22, by switching only valve PV2 from its position shown in Fig. 2, whereupon air under pressure is supplied through valve PV1 and line L2 to the upper end of the cylinder 74. It will be appreciated that when the machine is not in use, and the valve arrangement is in its rest condition, the pincers 22 remain closed. Furthermore, when they are initially closed onto the shoe upper, the closing force is only under the action of the spring 76. Thus, the risk of danger to the operator by trapping his fingers in the pincers is mitigated. For tensioning the upper U over its last L, once the full gripping force is applied to the pincers 22, a piston-and-cylinder arrangement generally designated 82 is provided, mounted on the base plate 40. A piston rod 84 of said arrangement carries the shoe support 20. The arrangement 82 together with the piston-and-cylinder arrangements 48 constitute drive means of the machine. In the operation of the machine, the operator first places a shoe comprising an upper U on a last L, with an insole I on the last bottom, on the shoe support 20 and inserts the lasting marginal portions of the upper in the array of pincers 22, which are at this time held open by operation of valve PV2 as aforesaid. At this time, the uppermost portion of each pincer 22 lies above the wiping plane, i.e. the plane of the wiper plates 28. When the upper is loaded in this manner, valve PV2 is released so that the pincer jaws 68 close under the force of the spring 76. The upper is now held under light gripping pressure. Air under pressure is then supplied to each piston-and-cylinder arrangement 60, whereupon each pincer 22 is caused to slide along its arcuate slide surface 52 and thus to move inwardly and downwardly in relation to the shoe. The centre of curvature of the slide surface 52 is indicated in Fig. 2 at A; it will be observed from Fig. 2 that the distance of the edge of the shoe from the centre of curvature A is only slightly greater than the distance of the end of the jaws 66, 68, from that centre, so that, as the pincers pivot about A, they pass close .to the edge of the last. It will of course be appreciated that the thickness of the upper U has to be taken into account in determining the position of A. Because of. the relationship between the centre of curvature A and the shoe, pivoting the pincers will not, in many instances, cause significant relative movement to take place between the shoe upper and the pincers so that in such cases it could be envisaged that the slipping grip could be dispensed with. At the end of this pivoting movement, the ends of the pincers 22 lie beneath the insole I (see the position indicated in chain-dotline in Fig. 2) , such that the upper U has been wrapped around the feather edge of the last L. In this position, the pincers 22 have now moved below the wiping plane, so as not to impede the subsequent inward movement of the wiper plates 28. Thereafter, the piston-and-cylinder arrangement 82, and if desired the piston-and-cylinder arrangements 48, are actuated, in a sequence according to the style of shoe being operated upon, to cause the upper U to be tensioned about the last L and to bring the insole I to a level just about the wiping plane. For tensioning the upper it is of course necessary first to switch the gripping pressure to high, this being achieved by actuation of the valves PV1, PV2 as above described. At this stage the operator can adjust the position of the upper on its last by discretionary pulling of the pincers 22, using levers 30 (Fig. 1) ; it will be appreciated that whereas only four such handles are shown in this Figure, the number of levers provided will be the same as the number of pincers, one being associated with each pincer. When the operator is satisfied with the position of the upper U on its last L, he initiates the inward movement of the wiper assembly 28 which thus engages the shoe upper and "traps" it against the insole I, the pincers 22 being released, by actuation of valve PV1, during the inward movement of the wiper assembly 28 and in timed relation therewith and in a desired sequence, thus to ensure that the tension in the upper U is maintained during such transfer. At the same time, the toe band 34 is applied. With the shoe thus trapped by the wiper assembly 28 in an intermediate position, adhesive is then applied to the forepart marginal portions of the insole by means of the imprinter 38, whereafter, upon movement of that imprinter to an out-of-the-way position, the inward movement of the wiper assembly 28 is continued to wipe the lasting marginal portions of the upper over and press them against the corresponding marginal portions of the insole I to which the adhesive has been applied. Bedding pressure is then applied between the wiper assembly 28 and the toe pad 32, in the usual manner. During such bedding pressure, each pincer 22 is moved to its closed condition, by means of the spring 76, upon de-actuation of valve PV2. If desired, in order to facilitate the insertion of the marginal portions of the upper into the pincers 22, the shoe support 20 of the machine may be mounted for tilting action about an axis extending transversely of the shoe bottom whereby the toe end of a last L placed thereon is initially low in relation to the toe pincer 22 and, at the end of the tilting movement, is raised in relation to the toe pincer, further drive means (not shown) being provided for effecting such movement. Such a tilting shoe support is conventional and will not be further described herein.

Claims: Claims; 1. Pulling over and :toe lasting machine comprising a shoe support (20) for supporting a shoe comprising a shoe upper (U) on a last (L) and an. insole (I) on the last bottom, a plurality of pincers (22) , including toe and forepart pincers, arranged about the shoe support (20) , pincer-closing means (70-76) for effecting the closure of each pincer (22) thus to cause lasting marginal portions of the upper of a shoe supported by the shoe support (20) to be gripped by the pincers (22) , drive means (82) for effecting relative movement, heightwise of the bottom of a shoe supported by the shoe support (20) , between the shoe support (20) and the pincers (22) , thus to tension a shoe upper (U) gripped as aforesaid over its last (L) , and a wiper assembly (28) for engaging the lasting marginal portions of the shoe upper (U) tensioned as aforesaid and for wiping said portions inwardly over and pressing them against corresponding marginal portions of the insole (I) , characterised in that auxiliary drive means (50-64) is provided whereby prior to the operation of the drive means (82) each pincer (22) is caused to move relative to the shoe support (20) with a component of inward movement. 2. Machine according to Claim 1 characterised in that the drive means (82) is effective to move the shoe support (20) heightwise relative to the pincers (22) through a pre-set distance to bring the bottom of a shoe supported by the shoe support (20) into the plane of the wiper assembly (28) , and the auxiliary drive means (50-64) is effective to move the pincers (22) as aforesaid to bring the pincers (22) to a position in which they do not impede the operation of the wiper assembly (28) . 3. Machine according to Claim 2 characterised in that the pincers (22) are moved through a pre-set distance under the action of the auxiliary drive means (50-64) . 4. Machine according to Claim 1 characterised in that each pincer (22) is mounted for pivotal movement about an axis (A) , the arrangement being such that, with a shoe supported by the shoe support (20) , said axis (A) is spaced from the edge of the shoe by a distance only slightly greater than the distance between said axis (A) and the end of the pincer (22) . 5. Machine according to Claim 4 characterised in that the pincer (22) is so positioned in relation to its pivotal axis (A) that the component of inward movement is greater than that of movement heightwise of the shoe. 6. Machine according Claim 1 characterised in that under the action of the pincer-closing means (70-76) the pincers (22) are caused to grip the shoe upper (U) with a reduced pressure during the operation of the auxiliary drive means (50-64) and thereafter with an increased pressure. 7. Machine according to Claim 6 characterised in that the reduced presssure applied to the pincer-closing means (70-76) is applied by a spring arrangement (70) , while the increased pressure is applied by fluid pressure operated means (72, 74), said latter means (72, 74) also acting, against the spring arrangement (70) , to open the pincers (22) for the insertion of the lasting marginal portions of a shoe upper (U) therein.

Inventors: BROENING MANFRED, FICHTNER RUDI, GIEBEL GERHARD, BROENING, MANFRED, FICHTNER, RUDI, GIEBEL, GERHARD
Applicants: BRITISH UNITED SHOE MACHINERY, DVSG PATENTVERWALTUNGS GMBH, VER SCHUHMASCH GMBH, BRITISH UNITED SHOE MACHINERY LIMITED, DEUTSCHE VEREINIGTE SCHUHMASCHINEN GMBH
Application year: 1989
Main classification: A43D21
IPC codes: A43D21, A43D23