GB2288312A - Shoe lasting machine - Google Patents

Abstract

The machine comprises a shoe support for supporting a shoe on its last for e.g. a heel seat and side lasting operation to be performed thereon. The machine has a pneumatic-hydraulic control circuit, including an intensifier (I) and also programmable pressure-regulating devices (PV11, PV12, PV3) by which the pressure urging the shoe into a datum position and thereafter against the wiper plates (174) (both during the inwiping movement and for the application of bedding pressure) can be controlled in accordance with a programmed instruction. <IMAGE>

Description

SHOE LASTING MACHINE This invention is concerned with improvements in or relating to shoe lasting machines, more particularly pulling over and toe lasting machines and heel seat lasting machines, whether with or without side lasting instrumentalities, such machines conventionally comprising a shoe support for supporting a shoe comprising a shoe upper on a last with an insole on the last bottom, wiper means, comprising a pair of wiper plates movable inwardly whereby to wipe lasting marginal portions of such shoe upper over and press them against corresponding marginal portions of such insole, and fluid pressure operated means for urging the shoe against the wiper plates after inward movement of the latter.

In general shoe lasting machines are either pneumatically operated or hydraulically operated.

Pneumatically operated machines are considered to be advantageous, at least where a factory source of compressed air is provided, in that they are less expensive in construction and their maintenance is less demanding, but in terms of speed of operation they tend to be generally slower than hydraulically operated machines, primarily because of the need for pressure to be built up before it becomes effective. When, therefore, it is a question of reducing cycle times, pneumatic operation is considered less attractive than hydraulic operation.Moreover, pneumatic operation does not readily lend itself to the application of relatively high pressures, such as may be required for "bedding" after the wiping operation has been completed, such bedding pressure being effective to fix the lasting marginal portions of the shoe upper in their wiped-over position and, in the case where adhesive has been applied between the lasting marginal portions of the shoe upper and corresponding marginal portions of the insole, to consolidate the bond therebetween.

It is thus one of the objects of the present invention to provide an improved shoe lasting machine in which the above disadvantages of pneumatically operated machines are mitigated.

The invention thus provides, in one of its several aspects, a shoe lasting machine comprising a shoe support for supporting a shoe comprising a shoe upper on a last with an insole on the last bottom, wiper means, comprising a pair of wiper plates movable inwardly whereby to wipe lasting marginal portions of such shoe upper over and press them against corresponding marginal portions of such insole, and fluid pressure operated means for urging the shoe against the wiper plates after inward movement of the latter, characterised in that the fluid pressure operated means comprises a hydraulic piston-and-cylinder arrangement to which hydraulic fluid is supplied from a control system comprising a pneumatic ally actuated piston-and-cylinder arrangement connected to the hydraulic piston-and-cylinder arrangement via a circuit including a non-return valve arrangement, and a pneumatically actuated intensifier by which in co-operation with the non-return valve arrangement the pressure of the hydraulic fluid in said circuit is intensified.

In one embodiment of the machine in accordance with the invention, which machine is a so-called heel seat lasting machine, the hydraulic piston-and-cylinder arrangement supports the shoe support for heightwise movement towards and away from a holddown (providing a height datum position), pneumatically operated means also being provided for moving the holddown into and out of an operative position in which it provides a height datum for the heel end of the shoe supported by a shoe support.

In the operation of such machine, after lasting marginal portions of the shoe upper have been wiped over corresponding marginal portions of the insole, the holddown is withdrawn thus to enable the hydraulic piston-and-cylinder arrangement to urge the shoe against the wiper plates in the application of bedding pressure.

In another embodiment of the invention, namely a pulling over and toe lasting machine, on the other hand, a toe pad is provided which urges the shoe down onto the shoe support (in this case providing a height datum position) and also against the wiper plates, bedding pressure in this case being applied when the shoe support is withdrawn.

Whichever embodiment is under consideration, however, by using the pneumatically actuated intensifier, bedding pressure can be readily applied utilising essentially pneumatically operated components acting through a "cushion" of hydraulic fluid. Thus the machines avail themselves of the advantages of pneumatic control while incorporating also some, at least, of the advantages of a hydraulic arrangement.

Preferably the control system also comprises means actuatable in timed relation with inward movement of the wiper plates for controlling the pressure under which air is supplied to the pneumatically actuated piston-and-cylinder arrangement during such inward movement. More particularly the pressure-controlling means is preferably connected to a first pressurised air source, a second pressurised air source also being provided having second pressure-controlling means, and switching means being provided by which one or other of said sources is selectively connected to the pneumatically actuated piston-and-cylinder arrangement.

In this way, the air pressure applied to the pneumatically actuated piston-and-cylinder arrangement can be varied during the operation of the machine. For example, in a heel seat lasting machine a rest position of the shoe support may be determined according to the first pressure-controlling means, while the second pressure-controlling means may be effective to control the pressure under which the shoe is pressed against the holddown, and thus the resistance to downward force applied to the shoe by the wiper plates as they move inwardly.For example, in the case of a light upper it may be desirable for the shoe support to yield readily to the in-wiping wiper plates, while in the case of a working boot, or other shoe having a relatively hard stiffener, the force applied by the wiper plates, which is a function of the pressure urging the shoe against the holddown, may have to be relatively high. The same situation may also be applicable in the case of a pulling over and toe lasting machine, where according to the nature of the footwear being operated upon the toe pad may be required to yield to a greater or lesser extent as the wipers move inwardly.

In order to reduce the risk of the holddown or shoe support, as the case may be, being moved out of its datum position by the force applied by the hydraulic piston-and-cylinder arrangement, furthermore, preferably the control system also comprises means for supplying a balancing pressure to the hydraulic piston-and-cylinder arrangement, whereby to balance the pressure applied to the hydraulic fluid by the pneumatically actuated pistonand-cylinder arrangement, said means being connected to a third pressurised air source having third pressurecontrolling means associated therewith. To this end, the pressure applied by the balancing pressure-supplying means is applied to the hydraulic piston-and-cylinder arrangement on the opposite side of its piston from the hydraulic fluid.In this way, therefore, the hydraulic cushion is disposed between the pressure supplied by the balancing pressure-supplying means on the one hand and the pneumatically actuated piston-and-cylinder arrangement on the other. It has been found that by using a balancing pressure in this way, the speed of reaction of the one pressure when the counter-pressure is removed is much greater than in the case where the pressure has first to build up.

Conveniently, moreover, means is also provided for supplying a return pressure to the hydraulic pistonand-cylinder arrangement, said means being connected to a fourth pressurised source, and further switching means being provided by which one or other of the third and fourth sources is selectively connected to the hydraulic piston-and-cylinder arrangement. In this way, the shoe support (in the case of a seat lasting machine) or toe pad (in the case of a pulling over and lasting machine) can readily be moved to an out-of-the-way position at a relatively fast speed, e.g. under full factory pressure.

In the case of a heel seat lasting machine the holddown may be held in its datum position by the pneumatically operated means for moving it to said position, in which case the pressure applied to the shoe via the control system must not exceed the counterpressure applied thereto by the holddown at least until inward movement of the wiper plates over the marginal portions of the shoe bottom has been initiated.

Similarly, in a pulling over and toe lasting machine the shoe support will generally be held in its datum position by pneumatically operated means and again the pressure applied to the shoe through the toe pad by the control system must not exceed the counter-pressure applied to the shoe by the shoe support until inward movement of the wiper plates over the marginal portions of the shoe bottom has been initiated.

It will be appreciated that the provision of a facility for varying the various applied pressures in accordance with the type of shoe or shoe material being operated upon is especially appropriate to machines which are electronically controlled, particularly machines which comprise or have associated therewith a.memory for storing style-related data. In accordance with the present invention, therefore, preferably each pressurecontrolling means comprises a pressure-setting device which is controllable in accordance with a programmed instruction.

The above and other of the various objects and several aspects of the invention will become clearer from the following detailed description, to be read with reference to the accompanying drawings, of one machine in accordance with the present invention. It will of course be appreciated 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 rear perspective view of the machine in accordance with the invention now to be described; Fig. 2 shows details of a wiper head of the machine shown in Fig. 1; Fig. 3 shows details of a jack post forming part of a shoe support of said machine; Fig. 4 is a fragmentary side view of the shoe support of the machine, showing also details of a holddown arrangement; and Fig. 5 is a diagrammatic representation indicating part of the control circuit of the machine.

The machine now to be described is a so-called heel seat and side lasting machine and is generally similar, except as hereinafter described, to the machine described in EP-A-0511811. The machine thus comprises a shoe support generally designated 20 (part only of which is shown in Fig. 4) for supporting, bottom up, a shoe, the toe end portion of which has already been lasted, for heel seat and side lasting operations to be performed thereon), said support comprising a jack post 22 (Figs. 3 and 4) including a last pin 24 which is capable of limited sliding movement, transversely of the longitudinal centre line of the shoe, in a slide 26 which itself is mounted for arcuate sliding movement, generally in the lengthwise direction of the shoe bottom, on a further slide 28 supported by the jack post 22.In this way it is possible for the heel seat region of the shoe bottom to be correctly levelled in relation to a wiping plane, to be referred to hereinafter, of the machine.

The shoe support 20 is a box-like structure comprising a frame 88 and support rods 78 (one only shown in Fig. 4), further details of which are described in the aforementioned EP-A.

The shoe support 20 comprises a shoe heel end positioning mechanism generally designated 86 (see Fig. 1) comprising a casting 87 which is carried on the frame portion 88. Supported by the casting 87 is a plate member 94 engageable by the backseam region of a shoe placed on the jack post 22. The plate 94 is spring-urged in a direction towards the jack post 22 about a pivot 96.

When engaged by a shoe, the plate is urged in a direction away from the jack post (clockwise, viewing Figure 3) and thus actuates an inductance switch 98 in response to actuation of which a control signal is supplied, as will be referred to hereinafter.

Also mounted on the casting 87 are two socalled seat clamp members 100, each for pivotal movement on the casting. A rearward end of one of the members 100, furthermore, is connected to a piston-and-cylinder arrangement 104, and the clamp members 100 are interconnected by a connecting rod (not shown) whereby they are moved equidistantly towards or away from one another. The effect of moving the clamp members 100 equidistantly towards the heel end of the shoe is to centralize the heel seat of the shoe, that is to say to locate the longitudinal centre line of the heel seat of the shoe coincident with the longitudinal centre line of the shoe support.

Also mounted on the casting 87 is a holddown (or heel seat height gauge) device 410 (Fig. 4) which comprises a pneumatic piston-and-cylinder arrangement 412 having a fixed stroke, and a piston rod 414 of said arrangement constitutes a holddown member for determining a height datum position for the heel seat of a shoe supported by the last pin 24. The piston-and-cylinder arrangement 412 is mounted on a bracket 416 carried by a slide member 418 which is in turn mounted for heightwise sliding movement in guideways 420. The guideways 420 are in turn secured to a support plate 422 and spaced therefrom to allow passage of the slide member 418. The support plate 422 is in turn secured on a cross-member 424 forming part of the main frame of the shoe support.

For effecting heightwise movement of the slide 418 a lead screw 426 is threadedly received in a threaded bore formed in the upper end of the slide, and for effecting rotation of the lead screw 426 a stepping motor 428 is provided which is mounted on an upper end of the support plate 422.

For securing the slide member 418, and thus the piston-and-cylinder arrangement 412, in adjusted heightwise position, locking means in the form of a further piston-and-cylinder arrangement 430 is also provided, mounted on a rear face of the support plate 422. A piston rod 432 of said arrangement extends through an aperture in the support plate and makes frictional contact with a rear face of the slide member 418, urging it into frictional engagement with the guideways 420.

For setting the position of the piston-andcylinder arrangement 412, and thus the datum position of the holddown, appropriate signals are supplied to the stepping motor 428, such signals may be provided in accordance with data which is stored for particular styles of shoes, such date being recalled each time a particular style is selected.

The jack post 22 comprises a post 116 (Fig. 3) on which the slide 28 is mounted for arcuate movement, as referred to above. The post 116 is slidable, in a direction heightwise of the bottom of a shoe supported by it, in a mounting thereof in the form of a casting 118 which is mounted for limited pivotal movement about an axis (not shown) extending widthwise of such shoe. For effecting heightwise movement of the post 116 a pistonand-cylinder arrangement 122' is mounted on the bottom end of the casting 188 and a piston rod thereof is operatively connected with the post 116. Also associated with the movement of the post 116 is a linear potentiometer 124 by which the heightwise position of the post 116 in relation to the casting 118 can be monitored.

For effecting limited rocking or pivotal movement of the casting 118 a piston-and-cylinder arrangement 128 is mounted on the frame of the shoe support 20 and is connected to a rod 130 which is pivotally connected at 132 to the casting 118. The piston-and-cylinder arrangement 128 is double-acting. A further pneumatic bar lock arrangement generally designated 134 acts on the rod 130 to lock it, and thus also the casting 118 and jack post 22, in position in a direction extending lengthwise of the shoe bottom.

The machine in accordance with the invention also comprises a heel band 152 (Figs. 1 and 2) which can be brought into engagement with the heel end of the shoe once the shoe has been positioned as aforesaid; it will of course be appreciated that, in order for the heel band to engage the heel end of the shoe, it will first be necessary to remove the shoe heel end positioning mechanism 86 from engagement therewith, as described in greater detail in the aforementioned EP-A.

The machine also comprises a wiper mechanism generally designated 170 (Fig. 2) which is of generally conventional construction and comprises a wiper head 172 which is slidable towards and away from the jack post 22 under the action of a piston-and-cylinder arrangement (not shown). The wiper head supports a pair of wiper plates 174 which, under the action of a cam plate 176, effect a forward and inward wiping movement over the heel end of a shoe. The wiper head 172 is bodily movable into an operative position, this position being determined by a block 178 engaging a back surface of the heel band 152 and urging the heel band into engagement with the backseam region of the shoe; in this way the wiper head is always positioned in a desired relationship with the heel end of the shoe prior to initiation of the forward and inward wiping movement of the wiper plates.More particularly, the block 178 is mounted on a spigot 180 which is accommodated within the wiper head and springurged in a direction away from the jack post, an adjustable stop pin 182 being provided in the block and engaging with a surface of the wiper head thus to determine the position of the block in relation to the wiper head. The block 178 is provided with two wings 178a, at opposite ends thereof, by which it engages and presses on the back surface of the heel band 152 at opposite sides of the backseam region thereof. It will thus be appreciated that by varying the position of the stop pin 182, the relationship between the initial position of the wipers prior to the start of the forward and inward wiping movement thereof, and thus the amount by which the wiper plates over-wipe the shoe upper, can be pre-set.

It will be appreciated that, because the heel band is, in its final stage of movement, urged into engagement with the heel end of the shoe by the advancing wiper head 172, it moves in a direction which is parallel, or substantially so, to the plane in which the heel seat of the shoe is located, thereby minimising the risk of dislodging the upper on its last, which could of course occur if the band followed an arcuate path into clamping engagement therewith.

Referring now to Fig. 5, the piston-andcylinder arrangement 122' forms part of a hydraulic system in which hydraulic fluid is supplied to an operative side of the piston of said arrangement thus to effect movement of the jack post 22 towards the holddown 414. To this end, a hydro-pneumatic piston-and-cylinder arrangement C1 is connected, at its output side, via a line L1 with the operative side of the piston of arrangement 122', the line L1 including a non-return valve arrangement HV1. For operating piston-and-cylinder arrangement C1, moreover, air under pressure is supplied to its input side through a solenoid valve SVll which, according to its operative position, is connected to one of two sources of air under pressure P11 and P12.Each pressure source has associated with it a pressure regulator valve resp. PV1l and PV12. A balancing pressure may also be applied to the opposite side of the piston of the arrangement 122', using air under pressure supplied via a further solenoid valve SV21 from one of two further sources of air under pressure P21 and P22.

Associated with at least the source P21 is a pressure regulator valve PV21; the source P22, which is used for applying a return pressure (to be referred to hereinafter), being preferably at full factory pressure, and thus requiring no pressure regulator valve (although of course one could be provided if required). Moreover, a further valve SV22 is interposed between the piston and solenoid valve SV21 in order at the appropriate time to discontinue the application of pressure to said opposite side of the piston.

The hydraulic fluid is also pressurised by means of an intensifier I which is again connected to the operative side of the piston of the arrangement 122', the intensifier comprising a large area piston with a small area output. The air under pressure is supplied to the large area piston from a further source of air under pressure P3, having associated therewith a pressure regulator valve PV3, the piston being connected to the air source via a solenoid valve SV3.

During the return stroke of the piston-andcylinder arrangement 122', furthermore, the non-return valve arrangement HV1 can be bypassed through a further solenoid valve SV4.

When a shoe is to be lasted, the operator first places the shoe, which has already been toe-lasted, on the last pin 24 and then urges the shoe towards the plate member 94, the slide 28, and the last pin therewith thus being caused to slide in the shoe-lengthwise direction; in addition the jack post 22, which is at this stage under merely a balancing pressure applied through the piston-and-cylinder arrangement 128 to facilitate this, moves also towards the plate 94. Upon contact between the backseam of the shoe and the plate 94, the inductance switch 98 is actuated and a signal is thus generated in response to which firstly the holddown device 410 is moved from an out-of-the-way position into its height datum position.At this stage, furthermore, the balancing pressure applied, while the jack post 22 is in its rest position, to the opposite side of the piston of the arrangement 122' from the pressure source P21 is removed, by switching solenoid valve SV22, and thus air under pressure supplied to the piston-and-cylinder arrangement C1 from the pressure source P11 causes the jack post 22 to rise to bring the heel seat of the shoe insole into engagement with the holddown device 410 thus to bring the heel seat of the shoe bottom to the height datum. With the shoe thus positioned at the height datum, furthermore, the seat clamp members 100 are moved inwards to clamp the shoe and centralise it, whereafter the holddown device 410 may be retracted.Moreover, solenoid valve SV3 is at this stage in its position shown in Fig. 5, that is to say no pressure is applied to the intensifier I.

When the shoe is positioned to the satisfaction of the operator both in the shoe-lengthwise direction and also at the height datum, the heel band 152 is moved into clamping engagement with the heel end of the shoe, and inward wiping movement of the wiper plates 174 may then be initiated. At the start of this inward movement, solenoid valves SV11 and SV12 are switched, thus admitting air under pressure from the source P12 to the arrangement C1, and thus to the arrangement 122'.This pressure can of course be set according to the nature of the material of which the shoe is made; for example, in the case of a shoe having a readily deformable heel end stiffener, which requires little force from the wiper plates in order to cause it to conform to the shoe last, the pressure regulated by PV12 can be relatively low, whereas in the case of a heavy working boot with a relatively hard heel end stiffener it may be desired to exert a significantly higher pressure, which has the effect of increasing the pressure applied to the lasting marginal portions by the wiper plates.

When the wiper plates 174 have completed their inwiping movement, and with solenoid valve SV4 in the position shown in Fig. 5, solenoid valves SVl1 and SV12 are de-actuated and solenoid valve SV3 actuated, whereby the intensifier I is brought into operation thus to apply bedding pressure to the inwiped lasting marginal portions (between which and the corresponding marginal portions of the insole, as described in detail in the aforementioned EP-A, adhesive will have been applied prior to the inwiping movement being effected). The bedding pressure remains applied according to the time required for ensuring a consolidated bond between the inwiped lasting marginal portions and the corresponding marginal portions of the insole.

At the end of the dwell time, the bedding pressure is relieved by de-actuating solenoid valve SV3.

At the same time, the wiper head 172 is retracted, the wiper plates 174 retracting within the wiper head 172, and the heel band 152 is released. At the same time, solenoid valve SV4 is actuated, as is also solenoid valve SV21 which, through de-actuated solenoid valve S22, connects the opposite side of the piston of the arrangement 122' to the pressure source P22, whereby the last post is returned under full factory air pressure to its initial rest position.

It has been found that by using such a pneumatic-hydraulic circuit, reaction times can be improved, and thus the overall cycle time of the machine can be reduced, while ensuring adequate pressures are applied to the shoe during the operation of the machine.

Furthermore, the pressure regulator valves PV11, PV12, PV21 and PV3 are preferably capable of being set in accordance with a programmed instruction; this is particularly desirable in the case of PV12 and, to a large extent PV3. By rendering these devices readily programmable, along with other programmable features of the operation of the machine, it is possible to set up a "library" of style-related data so that upon presentation of a shoe of a particular style it is necessary only to access the relevant data for the machine to be set to operate thereupon.

Whereas the machine described above by way of example is a machine for lasting heel seat and side portions of shoes, it will of course be appreciated that the various features of the invention are equally applicable to machines for lasting heel seat portions only of shoes and, indeed, in its broader aspects, is also applicable to other machines for lasting shoes, e.g.

toe lasting machines.

Claims (6)

Claims:

1. A shoe lasting machine comprising a shoe support for supporting a shoe comprising a shoe upper on a last with an insole on the last bottom, wiper means, comprising a pair of wiper plates movable inwardly whereby to wipe lasting marginal portions of such shoe upper over and press them against corresponding marginal portions of such insole, and fluid pressure operated means for urging the shoe against the wiper plates after inward movement of the latter, characterised in that the fluid pressure operated means comprises a hydraulic piston-and-cylinder arrangement to which hydraulic fluid is supplied from a control system comprising a pneumatically actuated piston-and-cylinder arrangement connected to the hydraulic piston-andcylinder arrangement via a circuit including a non-return valve arrangement, and a pneumatically actuated intensifier by which in cooperation with the non-return valve arrangement the pressure of the hydraulic fluid in said circuit is intensified.

2. A machine according to Claim 1 characterised in that the control system also comprises first means actuatable in timed relation with inward movement of the wiper plates for controlling the pressure under which air is supplied to the pneumatically actuated piston-and-cylinder arrangement during such inward movement.

3. A machine according to Claim 2 characterised in that the first pressure-controlling means is connected to a first pressurised air source, in that a second pressurised air source is provided having a second pressure-controlling means, in that switching means is also provided by which one or other of said sources is selectively connected to the pneumatically actuated piston-and-cylinder arrangement,

4. A machine according to Claim 3 characterised in that the control system also comprises means for supplying a balancing pressure to the hydraulic piston-and-cylinder arrangement, whereby to balance the pressure applied to the hydraulic fluid by the pneumatically actuated piston-and-cylinder arrangement, said means being connected to a third pressurised air source having third pressure-controlling means associated therewith.

5. A machine according to Claim 3 or Claim 4 characterised in that means is also provided for supplying a return pressure to the hydraulic piston-andcylinder arrangement, said means being connected to a fourth pressurised source, and in that further switching means is provided by which one or other of the third and fourth sources is selectively connected to the hydraulic piston-andcylinder arrangement.

6. A machine according to any one of the preceding Claims characterised in that the (or each) pressure-controlling means comprises a pressure-setting device which is controllable in accordance with a programmed instruction.