US3778856A

US3778856A - String lasting

Info

Publication number: US3778856A
Application number: US00303819A
Authority: US
Inventors: G Chriestie; E Bressington
Original assignee: Salient Engineering Ltd
Current assignee: Salient Engineering Ltd
Priority date: 1971-11-05
Filing date: 1972-11-06
Publication date: 1973-12-18
Anticipated expiration: 1990-12-18

Abstract

Apparatus for string lasting the uppers of shoes or boots has a power operated device for pulling the string. Clamping means, conveniently one or more bollards, are provided for holding the string and are mounted on a linear actuator such as pneumatic piston and cylinder device. The actuator is either carried by the base on which the last is mounted or is independent thereof and movable into a position where it reacts against the last.

Description

United States Patent [191 Christie et al.

[ Dec. 18, 1973 STRING LASTING [75] Inventors: Gerald Anthony Christie, Bath;

Edwin Thomas Bressington, Bristol, both of England [73] Assignee: Salient Engineering Limited, Bristol,

England [22] Filed: Nov. 6, 1972 [2]] App]. No.: 303,819

[30] Foreign Application Priority Data Nov. 5, i971 Great Britain 51,464/71 [52] US. Cl. l2/7.9 [51] Int. Cl A43d 15/00 [58] Field of Search l2/l R, 7, 7.9

[56] References Cited UNITED STATES PATENTS 3,474,475 10 1969 Fisk 12/79 Sahr l2/7.9 Miller l2/7.9

Primary Exanziner--Patrick D. Lawson Attorney-Irvin S. Thompson et al.

[5 7] ABSTRACT -Apparatus for string lasting the uppers of shoes or boots has a power operated device for pulling the string. Clamping means, conveniently one or more bollards, are provided'for holding the string and are mounted on a linear actuator such as pneumatic piston and cylinder device. The actuator is either carried by the base on which the last is mounted or is inde pendent thereof and movable into a position where it reacts against the last.

14 Claims, 6 Drawing Figures PATENTEU UEC 18 I973 SHEEF 2 UF 4 STRING LASTING This invention concerns a devicefor string lasting shoes or boots.

One commonly used method of shaping a shoe upper before attachment of a sole is for its margin to be stitched to form a complete peripheral hem trapping a string between the stitches and the margin. The string passes about one and a half times around the periphery with its free ends emerging from the hem generally on opposite sides of and near the widest part of theupper, just in front of the waist. The string is usually single part around the heel and doubled around the toe. When the upper is placed on a last and the free ends of the string are pulled the margin is contracted and folds inwardly so that the upper takes on the shape of the last. This string pulling is generally done by hand and despite the common use of protective gloves it is still damaging to the hands. It also requires a high degree of expertise to pull the string the correct amount and to the required tension every time. Mechanical means for pulling the string have been proposed but they have been complex, often attempting automatically to grasp the string and to prevent the grasping arms snapping back towards the operator in the event of string breakage. Also, they are generally machines serving a single specialist purpose, and the uppers have to be removed for subsequent processes. Examples may be found in British Patent Specifications Nos. 391550 and 1,253,448.

It is an object of this invention to eliminate hand pulling and to provide a reliable and uniform tensioning of the string with a simple mechanical aid that can be used, in some embodiments, on lasts mounted on other shoe making machinery.

According to the present invention there is provided a string lasting device comprising means for clamping a string and power means comprising two relatively movable parts, the clamping means being mounted on one part and the other part serving for abutment against the last or a workpiece thereon, wherein actuation of said power means with such abutment causes said clamping means to move away from the last.

Preferably the power means is a pneumatic or other fluid operated piston and cylinder assembly.

Such two-part power means may be mounted on a movable support that enables it to be brought into cooperation with the last or be moved away therefrom. The power means and support assembly may be counterweighted. In one preferred form the support is a hinged bracket, and that part of the power means which abuts the last may be mounted on a slideway directed towards the last when the bracket is in the cooperating position. Thus the power means is finally brought into abutment with the last by movement along the slideway after the bracket has been swung into the cooperating position.

Other movable supports include gallows by which the power means are suspended, or an overhead gantry along which a trolley suspending the power means may run. Alternatively, there may be a ground based trolley with a pivoting arm carrying the power means on the free end. Operation may be by a foot pedal or by a trigger mounted on the power means itself.

The string clamping means may simply be a bollard around which normally a single turn of the string is taken, but there may be twin bollards for dealing with the two different string ends. In the preferred form the or each bollard is formed with an annular groove acutely V-shaped at its base. The groove may be otherwise quite smooth. The pinching action of the groove on the string when the tension is applied by actuation of the power means and the locking action of the fall of the string passing over the standing part where it enters the groove is sufficient to hold the string fixed to the bollard if the fall is held by an operator with light tension. Alternatively, a cleat may provide the clamping means.

In order to control the tension of the string, means can be provided for arresting the travel of the string clamping means by stopping actuation of said power means when a predetermined string tension is achieved.

The invention may be performed in various ways and some constructional forms thereof will now be described, by way of example, with reference to the accompanying drawings, in which FIG. 1 is a side view ofa string pulling device according to the invention,

FIG. 2 shows diagrammatic plan and side views of the mounting arrangement of the device of FIG. 1,

FIG. 3 is a perspective view of another string pulling device,

FIG. 4 is a diagrammatic side elevation of a further string pulling device, and

FIGS. 5 and 6 are diagrammatic perspective views of other devices according to the invention.

In these figures, pneumatic cylinders are shown but in every case the air lines are omitted for clarity of drawing.

In FIGS. 1 and 2 a bollard 1 for securing the string is mounted on a pneumatic ram 2. The bollard 1 is a drum with a vertical axis and a circumferential V- section groove 3. The angle of the V is sharp and the base part la of the bollard is of greater diameter than the hand part lb. The bollard is preferably made from a material that will give a smooth finish, such as silver steel.

The cylinder 4 of the ram has secured at one end a block 5, of expanded polyurethane or hard rubber for example, recessed at 6 to fit the heel portion of a shoe upper on a last 7 indicated in outline in FIG. 2. The piston rod 8 projects from the other end of the cylinder and the bollard l is mounted thereon by means of an arm 9 which extends back over the cylinder 5. The cylinder 5 is carried by an L-shaped mounting 10 at said other end and is free to move in the axial direction by means of headed studs 11 projecting downwardly from the longer, horizontal portion of the mounting l0 and engaging in a slideway 12. The latter is mounted between the ends of the arms of a pivoting bracket 13. The pivot axis 14 is horizontal and transverse to the ram axis, and beyond that axis from the ram 2 the arms turn up and slightly back and are loaded with counterweights 15. A guard box 16 is mounted with the cylinder and protects the operator against the piston rod as it performs its stroke.

For pulling the string, the bracket 13 is swung down so that the ram 2 is horizontal, as shown, and comes into registry with the heel of the last 7 and the cylinder 4 is slid forwards, until the block 5 abuts the heel. A

free string end is led to the bollard and a single turn taken round it, the turn lying in the groove 3 and the fall being held under slight tension by the operator. The ram is then actuated, for example by a foot pedal (not shown). The piston rod 8 extends, moving the bollard away from the heel and thereby pulling the string. The string does not slip because of the pinching action of the groove and the locking action of the string crossing itself within the groove.

It will be noted that the ram reacts directly against the last on which the shoe upper is mounted. Thus no significant external forces are produced, the string pulling forces being confined to the last and the shoe upper on it and to the ram. The bracket can therefore be of light construction. This arrangement is also safe in the event of string breakage, for there will be no string gripping element flying back beyond its normal travel.

When the string pulling is complete, the ram is retracted and the bracket is swung up clear of the last to give free access to the formed upper.

The last may be fixed and independent, or it may be part of other shoe making machinery, the bracket then being mounted on the machinery structure. In the latter case the last could be arranged to be movable from a position where the string pulling device is used to a position where another shoe making process is carried out. One particular preferred form of use is in conjunction with moulding machines for forming the sole and heel, such as the Pegasus machine of Salient Engineering Limited, the bracket there being mounted on top of the casing. As soon as the upper is formed by the string pulling and the bracket swung up, moulding can be carried out on the same last.

FIG. 3 shows a pneumatic ram string pulling device 30 of similar construction to that of FIGS. 1 and 2 mounted at one end of an L-shaped arm 31. Some of the parts of the ram identical with those of FIGS. 1 and 2 are similarly reference, but with indices. The arms 31 project from one end of a pivoting bar 32 carrying at its other end a counterbalancing bar 33. The pivot axis is horizontal, transverse to the ram axis, and the pivoting assembly is shown in the ready-to-use position with the axis of the ram horizontal. The last is not shown for clarity of the drawing. The assembly is mounted at the end of a horizontal bar 34 adjustably supported by a clamp 35 at the top of a column 36 upstanding from a base 37. The base also incorporates a clamp by which the height of the column, and hence of the working position of the ram, can be adjusted.

The base is fixed on a bench surface which also provides means such as the bolt holes 38 for securing a last or last holder. It will be appreciated that many different kinds and sizes of lasts can be fitted and the pivoting assembly adjusted to give the correct ram alignment and proximity. The string pulling follows a similar sequence to that described above, again with no pulling forces transmitted to the pivoting assembly or its support. Operation of the ram is by a foot pedal 39.

The device of FIG. 4 also uses a ram that reacts directly against a last. It comprises a gallows 40 from the end of whose overhanging arm depends a vertical rod 41. A sliding bracket 42 runs on this rod and supports a pivoting arm 43 carrying at its lower end a pneumatic pulling device 44 comprising a ram titted with a ho]- lard. A counterweight 45 is guided vertically on the uprights of the gallows 40 and is connected via a wire 46 trained over pulleys 47 to the bracket 42.-The device is operated by a foot pedal 48.

This device may be used in conjunction with a machine which presents lasts fitted with uppers in succession to the operator's position. He has only to swing the counterweighted device up to the heel, take a turn around the bollard with the string, operate the foot pedal 48 and then release the string and swing the device away again to complete the string pulling operation.

Rather than bringing the lasts to the operator the gallows may be arranged to swing through an are about a vertical axis so that the operator can deal with an array of stationary lasts. In this case, it may be more convenient to have the operation of the device actuated by a finger trigger.

In FIG. 5 there is shown a pneumatic ram string pulling device 50 suspended from an overhead gantry 51 by means of articulated arms 52 and a trolley 53 which runs along the gantry. The device can be presented to an array of lasts below the gantry. This may be linear as shown, or circular or any other desired shape. Again, it is convenient to operate this device by a finger trigger indicated at 54.

In FIG. 6 a similar device is mounted at the end of an arm 61 pivotally carried on a trolley 62 which can be run along beside an array of lasts. This trolley may house an air bottle for the supply to the ram. Trigger operation is preferred here.

Alternatively, the device may be free, apart from a connecting air line, in which case the operator has even more freedom of application. Although the weight of the device does not make this unduly arduous each last may have an associated support on which temporarily to rest the ram device in an aligned position with the shoe upper for the string pulling operation. Such a support may also be provided for the counterweighted devices.

With the pneumatic rams described, the air pressure applied may be relieved automatically upon attaining a certain value corresponding to the desired tension.

The bollard may be oriented with a horizontal rather than vertical axis, and there may be twin bollards on the single ram. Other clamping means, such as cleats, may be used instead.

It will be understood that instead of pneumatic operation, it would be possible to use hydraulic cylinders or electric solenoids or other forms of linear actuator.

We claim:

I. A string lasting device comprising means for clamping string from either side of a lasted upper and a linear actuator for moving the clamping means apart from a last, wherein the linear actuator comprises two relatively movable parts, one carrying the clamping means and the other having an abutment for engaging directly against an upper on the last, and wherein operation of said actuator with such engagement causes said clamping means to move in the linear direction away from the last.

2. A device as claimed in claim 1, wherein said linear actuator is a fluid operated piston and cylinder assembly.

3. A device as claimed in claim 1, and including a movable support which mounts said linear actuator and enables it to be brought into co-operation with the last or to be moved away therefrom.

4. A device as claimed in claim 3, wherein the support is pivoted and counterweighted.

5. A device as claimed in claim 3, and including a gallows from which said linear actuator is suspended.

6. A device as claimed in claim 3, and including an overhead gantry and a trolley running on said gantry from which said linear actuator is suspended.

7. A device as claimed in claim 3, and including a ground based trolley and a pivoting arm extending therefrom, at the end of which said linear actuator is mounted.

8. A device as claimed in claim 3, wherein a slideway carries that part of said linear actuator which serves to abut the last and is parallel to said linear direction.

9. A device as claimed in claim 1, wherein said string clamping means is at least one bollard.

10. A device as claimed in claim 9, wherein the boltor when a predetermined string tension is achieved.

Claims

1. A string lasting device comprising means for clamping string from either side of a lasted upper and a linear actuator for moving the clamping means apart from a last, wherein the linear actuator comprises two relatively movable parts, one carrying the clamping means and the other having an abutment for engaging directly against an upper on the last, and wherein operation of said actuator with such engagement causes said clamping means to move in the linear direction away from the last.

10. A device as claimed in claim 9, wherein the bollard is formed with an annular groove, acutely V-shaped at its base, for receiving the string.

11. A device as claimed in claim 10, wherein said groove is smooth surfaced.

12. A device as claimed in claim 9, wherein the base part of the bollard is of greater diameter than the head part, the groove being the division between said parts.

13. A device as claimed in claim 1, wherein said string clamping means is a cleat.

14. A device as claimed in claim 1, wherein means are provided for stopping actuation of said linear actuator when a predetermined string tension is achieved.