Device for the heat moulding of footwear

Abstract

 This device consists of a support structure (1) for at least one moulding last (2), which will be matched to the inner cavity of the footwear being moulded (3) consisting of two front stretching lasts (4) and one rear extender last (5), in relation to the shoe in question; whereby the front stretching lasts (4) can either be brought nearer to each other or reciprocally taken further away from each other, by operating micrometric means of movement (7) operated by controls (10) also operating the means of movement (9) of the extender last (5), parallel to the long side of the stretching lasts (4), manufactured in a heat-­conducting material and having heating devices (11) operated by the controls (10).

Description

[0001] This invention describes a device for the heat moulding of general purpose footwear, either with flat heels, such as moccasins, or high ones, such as sports shoes or boots.

[0002] Shoe moulds currently available on the market are manufactured in the form of an implement coming in two halves which usually imitates the shape of the foot and which is inserted inside the footwear itself.

[0003] These two halves are arranged inside the footwear, one at the front and the other at the back, so that by means of manually operated mechanisms, they can reciprocally either be taken further away from each other during the moulding phase, or brought nearer to each other prior for their removal.

[0004] It is also usual practice, for said footwear to be heated immediately prior to the moulding phase, in order to render the skin or leather more pliable. Certain disadvantages are, however, involved in this heating operation, owing to the fact that the footwear has to be heated separate from the device in question, with the consequence that when the footwear is subsequently placed upon the device, it has already lost some of its heat, the colder the device, the greater the heat loss is.

[0005] Furthermore, equipment of the type described above has further disadvantages, the main one being the difficulty of correctly regulating the stretching and shaping force.

[0006] Another disadvantage of this technique is the excessive length of time taken up in preparing the footwear for these essential heating operations, which have to be carried out prior to the moulding phase.

[0007] There is also the difficulty of the footwear being correctly heated, to avoid too much heat being lost when they are fitted to the moulds prior to the moulding phase.

[0008] If the footwear is not sufficiently heated or the moulds are too cold, the excessive temperature difference may lead to the rapid cooling of the footwear, subsequently leading to uneven patches of skin and leather being subjected to stretching, which may even cause the skin to tear.

[0009] It is, therefore, the purpose of this invention to provide a device that will enable footwear moulding operations to be simply and economically speeded up, in such a way that both the heating and the moulding operations can be performed in a single operation, so the heating of the skin or leather of the footwear will take place at the same time as the moulding operations.

[0010] A further purpose of this invention is to enable the moulding force applied to the footwear to be more accurately regulated.

[0011] In the form of the claims characterising it, this invention resolves the above problems in the form of a device, consisting of a support structure for at least one moulding last which will be matched to the inner cavity of the footwear being moulded, consisting of two front stretching lasts and one rear extender last in relation to the shoe. The stretching lasts can either be brought nearer to each other or reciprocally taken further away from each other, by operating micrometric means of movement, operated from the controls that also operate the means of movement of the extender last, parallel to the long side of the stretching lasts.

[0012] These stretching lasts are manufactured in a heat-­conducting material and have heating devices that are operated by the controls.

[0013] An advantage of this invention, therefore, is the possibility of the temperature of the footwear being correctly set and regulated during the moulding phase, to guarantee perfect manufacture. This invention is subsequently explained in greater detail in the following description with the diagrams enclosed, these being only of one example of the invention and not to be interpreted as being in any way restrictive.

Fig. 1 is a diagram showing a side view, wherein some of the parts are shown in cross-section to give a clearer view of the others, this device being according to the terms of this invention.

Fig. 2 is a diagram showing a top view, wherein some of the parts are shown in cross-section to give a clearer view of the others, this device being according to the terms of this invention and having been manufactured in terms of the version shown in Fig. 1.

Fig. 3 is a diagram showing the III-III section as in Fig. 1.

Fig. 4 is a perspective diagram of the device in the terms of this invention and manufactured according to the structural version shown in Fig. 1.

[0014] With reference to the enclosed figures, the device manufactured in the terms of this invention consists of a framework or support structure, 1, for at least one moulding last, 2, which will be matched to the inner cavity of the footwear, 3, being moulded, in such a way as to be suitable for any kind or size of shoe whatsoever.

[0015] As can be seen from the study of Figures 2 and 4, this device consists of two moulding lasts, 2, one for the right shoe and the other for the left one, thus enabling both shoes of each pair to be moulded at the same time.

[0016] Each moulding last, 2, consists of two front stretching lasts, 4, and one rear extender last, 5, both of these being in relation to said moulding last, 2. In fact, the stretching lasts, 4, will be inserted inside the shoe, 3, so as to be perfectly matched to the toe part of said shoe, 3, whereas the extender last, 5, will be matched with the heel part of the shoe, 3.

[0017] The stretching lasts, 4, are mobile and can be brought nearer to each other or reciprocally taken further away from each other, whereas, the extender last, 5, is mobile but can be moved away from or towards the stretching lasts, 4, and parallel to the long side of the moulding last, 2, that it is part of.

[0018] The stretching lasts, 4, and the extender last, 5, are interchangeably attached to the bottoms of vertical rods, 6 and 8, respectively held up by the support structure, 1.

[0019] As can be seen in Fig. 1, support structure, 1, is basically shaped like an inverted "L", consisting of two tubular arms, one perpendicular to the other, said "L" shape being attached to a platform base, 24, at the lower end of the vertical arm. The inner side of the horizontal tubular arm of the support structure, 1, shown as No. 12 in the enclosed diagrams, supports the top ends of the rods, 6 and 8, and has a vertical guide, 13, at the bottom housing the rods, 6. These rods, 6, which rotate freely inside the guide, 13, are bent at the top into, 6S, and located along said arm, 12, more or less parallel to the longitudinal axis of said arm, 12.

[0020] Inside the arm, 12, the rods, 6, are rotated around their vertical axis by the means of movement, 7, depending which version of the device is being used, these consist of a mobile wedge shaped part, 15, running inside the arm, 12, with its own end aimed at the free ends of the 6S sections of the rods, 6, and located between these rods.

[0021] Furthermore, the wedge shaped part, 15, also engages in the screw thread of a threaded bar, 16, mechanically linked to a reducer motor, 17, which is externally supported by the arm, 12. The reducer motor, 17, is operated by the controls, 10, of known type, which may, for example, be located on the horizontal arm, 12.

[0022] The bar, 16, is supported on the inner side of the arm, 12, and can only rotate around its own axis. When the reducer motor, 17, is driven in either direction, the threaded bar, 16, will rotate accordingly, and since it cannot move axially, this causes the wedge shaped part, 15, to travel forward in the direction of the arrow, f, as in Figures 1 and 2. This movement of the wedge shaped part, 15, in either direction brings it closer to or further away from the 6S sections of the rods, 6, thus resulting in the reciprocal action of the rods, 6, around their vertical axis.

[0023] The wedge shaped part, 15, has a triangular prism shaped part, 25, on top of it moving inside an appropriate slot, 26, of the horizontal arm, 12, acting both as rotation indicator to the rods, 6, and as a stop to prevent the wedge shaped part, 15, from rotating around the bar, 16, while the latter itself is rotating. For this reason, the part of the horizontal arm, 12, on which the prism shaped part, 25, travels, has a graduated scale, 30, (see Fig. 2), and together with the prism shaped part, 25, acting as index, this indicates the angle of rotation of the rods, 6.

[0024] The prism shaped part, 25, which is tapered at the top, intercepts the limit switches, 21, controlled by the controls, 10, stopping the reducer motor, 17, the moment the limit switch, 20, is tripped by the prism shaped part, 25. The position of the limit switch, 20, can be adjusted parallel to the direction of the bar, 16, thus enabling the wedge shaped part, 15, to reach its furthest position forward: which means that the maximum angle of opening of the stretching lasts, 4, is determined by the position of the limit switch, 20.

[0025] The top end of the rod, 8, forms a cursor, 8c, which is held so that it will run freely upon the guides, 14, inside the horizontal arm, 12. These guides, 14, may, for example, consist of a horizontal rod extending for the length of the horizontal arm, 12. The rod, 14, and the threaded bar, 16, are aligned and consecutive, being held at their near ends by a support, 27, inside said horizontal arm, 12.

[0026] The cursor, 8c, is moved along the rod, 14, by appropriate means of movement, 9, consisting of a hydraulic cylinder, 18, with a piston rod, 18s, attached to said cursor, 8c, (see Fig. 1) at its free end.

[0027] This hydraulic cylinder, 18, is fed by a suitable source of fluid under pressure, 19, which is also operated by the controls, 10.

[0028] In the version shown in Fig. 2, the means of movement, 9, consists of a threaded bar, 22, whose screw thread, for example, engages with the cursor, 8c, and is held in place by the support, 27, and the horizontal arm, 12, around it. The bar, 22, can only rotate in either direction around its own axis when it is moved in this way by a suitable reducer motor, 23, external to the horizontal arm, 12, and which is operated from the controls, 10.

[0029] The cursor, 8c, also has its own prism shaped part, 28, on top of it, moving inside an appropriate slot, 29, located in the horizontal arm, 12. An appropriate graduated scale, 31, is also located at the side of the slot, 29, in the horizontal arm, 12, indicating the relative movement of the cursor, 8c, and consequently, of the rod, 8, in relation to the horizontal arm, 12. Operation of the means of movement, 9, causes a movement of the rod, 8, and a subsequent movement of the extender last, 5, along the horizontal arm, 12.

[0030] The prism shaped part, 28, also trips a respective limit switch, 21, controlled by the controls, 10, either disenabling the source of fluid, 19, or stopping the reducer motor, 23, the moment the limit switch, 21, is tripped by the prism shaped part, 28. The position of the limit switch, 21, can be adjusted parallel to the direction of the axis of the rod, 14.

[0031] A further basic feature of this device in the terms of this invention is the fact that at least the stretching lasts, 4, are made of heat conducting materials and have heating devices (11) which will heat said stretching lasts evenly all over. Ideally the stretching lasts, 4, and the extender last, 5, should be manufactured in die cast aluminium, while the heating devices, 11, should consist of electric resistances set in the material of the stretching lasts, 4.

[0032] The controls, 10, also consist of timers and thermometers enabling the resistances, 11, to reach and maintain a certain temperature for a certain period of time. The controls, 10, also contain adjustable means of pre-determining the rotation and travel respectively of the stretching lasts, 4, and the extender last, 5.

[0033] A device of this kind will, therefore, enable a certain degree of accuracy in pre-determining the moulding force which the footwear, 3, is to undergo and in using threaded bars, 16 and 22, of equal accuracy; and with a fine pitch thread permits a further improvement in accuracy.

[0034] Whereas, the use of the hydraulic cylinder, 18, enables the extender last, 5, to cover distances larger in scale than those permitted by the threaded bar, 22. Furthermore, to a certain degree, it also enables the moulding force to be gentler.

[0035] As far as time is concerned, the use of the controls, 10, which can be accurately adjusted, enables every shoe, 3, to be fitted to its respective moulding last, 2, and also enables the moulding phase to be controlled on both shoes, 3, at the same time and force.

[0036] Finally, the presence of the resistances, 11, enables uniform and homogeneous heating, thus avoiding any critical situations arising due to undue concentrations of heat while the leather is being worked.

[0037] The fact that the moulding lasts are manufactured in three parts enables further operations to be be carried out on the footwear, 3, during moulding, and it also enables said moulding lasts, 2, to be used for more than one kind of footwear, 3, with slight variations, thus rendering the device more economical and making it unnecessary in some cases for the moulding lasts, 2, to be changed.

[0038] This invention can be subjected to numerous modifications and versions, all of which are within the terms of this invention. Furthermore all of these details may be replaced by their technical equivalents.

[0039] Figure 4 shows a further modification of this device in the terms of this invention, where the overall vertical dimensions have been considerably reduced and the stretching lasts, 4, and the extender last, 5, have been ideally manufactured especially for the moulding of flat footwear or moccasins only.

Claims

1. Device for the heat moulding of footwear, wherein said device consists of a support structure (1) for at least one moulding last (2), which will be almost perfectly matched to the cavity of the footwear being moulded (3) and divided into two front stretching lasts (4) and one rear extender last (5), of the shoe being moulded (3); said front stretching lasts (4), stretching lengthways along the longest side of the moulding last (2) and being taken, so as to be interchangeable, by respective rods (6) moving from said support structure (1); said rods (6) either being brought nearer to each other or reciprocally taken further away from each other, by operating respective micrometric means of movement (7), fixed to said support structure (1); the extender last (5), because it is interchangeable on its rod (8) extending from said support structure (1) so that its position can be regulated to be further away from or nearer to said stretching lasts (4) parallel to their longest side and operated by respective micrometric means of movement (9) acting upon said rod (8) and fixed to said support structure (1); said means of movement (7 and 9) of said of said stretching lasts (4) and said extender lasts (5) being operated from the controls (10); whereby at least said stretching lasts (4) being manufactured in a heat-conducting material and either incorporating wholly or in part the heating devices (11) capable of evenly and homogeneously raising the temperature of said stretching lasts (4), said heating devices being operated from said controls (10) by means of which it is also possible to determine the temperature reached by said stretching lasts (4) and the amount of time that this temperature is maintained.

2. Device according to the description in claim 1, wherein said device consists of two moulding lasts (2), specular shaped in relation to their intermediate longitudinal surface, and moulded in such a way as to fundamentally match the cavity of the footwear of each pair of shoes being moulded (3).

3. Device according to the description of claim 1, wherein said support structure (1) is shaped like an inverted "L" and has a horizontal arm (12) with a vertical guide (13) extending beneath it which is hollow inside and which houses said pair of rods (8) in such a way that they can rotate around their respective axes; said pair of rods (8) being mechanically attached inside the horizontal arm (12) of said support structure (1) and by their top ends to their respective means of movement (9); the top end of the support rod (8) of said extender last (5) being supported and mobile along the guide means (14) and being moved by respective means of movement (9).

4. Device according to the description in claim 3, wherein said means of movement (7) of said stretching lasts (4) consist of a wedge shaped part (15) with its tapered and inserted between the top ends of said pair of rods (6) and engaging with the screw thread of at least one threaded bar (16) supported by the horizontal arm (12) of said support structure (1); said threaded bar (16) freely rotating and being axially stable in relation to said support structure (1) and being rotated around its own axis by a respective reducer motor (17) operated by said controls (10); limit switches with adjustable positions (20), tripped by said wedge shaped part (15) and acting upon said controls (10) to stop said wedge shaped part (15) and said rods (6).

5. Device according to the description in claim 3, wherein said support rod (8) of the extender last (5) is mechanically fixed to the piston rod (18s) of a hydraulic cylinder (18) operated in either direction by a source of fluid under pressure (19) operated from said controls (10); limit switches with adjustable positions (21) tripped by said rod (8) and acting upon said controls (10) to stop said rod and its partner rod (8).

6. Device according to the description in claim 1, wherein said support rod (8) of the extender last (5) engages with the screw thread of a respective threaded bar (22) which rotates freely around its own axis and is axially stable in relation to said support structure (1) and is mechanically connected to a respective reducer motor (23) operated from said controls (10).

7. Device according to the description in claim 1, wherein at least said stretching lasts (4) are manufactured in die cast aluminium incorporating said heating devices (11), said heating devices consisting of electric resistances operated by said controls (10).

Drawing