GB2239212A - Press - Google Patents

Abstract

A press for use in the textile industry for fusing fabrics, etc. has a fixed platen (12) and a movable platen (14). To generate the necessary pressure to produce fusion while still being of the quick action type the platens are moved from an open position to a closed position by a quick action, over-contra locking arm (19) and from the closed position to the pressure applying position by rotation of a pressure applying screw mechanism. <IMAGE>

Description

PRESS This invention relates to a press and in particular to a press for use in the textile industry.

Presses are used within the textile industry for the fusion of fabrics, for example, in a manufacturing of shirt collars. In the process the layers of material to be fused are placed under pressure and heated to the desired temperature to cause fusion to occur.

The pressure required to effect fusion at a temperature low enough to prevent scorching of the material is quite high, in the order of 1 to 3 kilograms per sq. centimeter. Presses are also used for transfer printing.

To-date only hydraulic or pneumatic presses have been able to produce required pressure with hydraulic being the preferred type due to the faster operating time achieveable under hydraulic mechanisms. However the hydraulic machines are large and expensive requiring a large through put to make them economically viable. There has been a need for an alternative to the hydraulic machines which could produce sufficient pressure quickly.

Accordingly, the present invention provides a press having a fixed platen and a movable platen, the movable platen being brought into close contact with the fixed platen by operation of an over-centre locking mechanism, the movable platen being movable from the close contact position to a pressure applying position by means of a pressure applying screw.

Preferably, the pressure applying screw is operated by movement of a handle connected to the head of the screw through an angular rotation of between 45" and 125 and preferably about 90".

Preferably, the handle is approximately 12" long.

Preferably, the movable platen is supported by spring means to a support frame connected to the spring pressure applying screw and the over centre locking arm.

Preferably the spring means is a resiliently deformable plastics sheet.

Preferably the spring means is a plurality of disc spring washers.

Preferably the press is used for fusing textiles in the garment industry and the platens contain heating elements to fuse the textiles under heat and pressure.

In a second aspect the present invention provides a press comprising at least one pair of platens wherein the platens of the or each pair are brought into close relative contact position with each other, and the platens are moved from the close contact position to a pressure applying position by means of a pressure applying screw means.

In an alternative embodiment the movable platen moves into close contact with the fixed platen via operation of a high speed low torque motor driving a screw transport mechanism to which the movable platen is mounted and the movable platen is moved from close contact with the fixed platen into pressure applying position by means of a second motor arranged to provide high torque to the screw transport mechanism.

One preferred form of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 depicts a hand operated press according to one embodiment of invention; Figure 2 depicts the press of figure 1 in an open position; Figure 3 illustrates the platens and pressure exerting portion of the press of figure 1; Figure 4 is an elevation view of a spring element of the press; Figure 5 Is a plan view of the spring element of figure 4; Figure 6 illustrates in sectional view one method of combing spring element depicted in figure 4; Figure 7 illustrates in sectional view an alternative method of combing spring elements depicted in figure 4; and Figure 8 illustrates in partial section the pressure applying mechanism of figure 3.

Figure l shows in simplified terms a press 10 having a press housing 11. The press is of the small hand operated type with a lower platen 12 mounted to the press housing by adjusting screws 13. These adjusting screws allowed the height of the lower platen to be adjusted to accommodate the materials being pressed. An upper platen 14 is mounted to a upper platen movable arm 15 which allows the upper platen to be spaced from the lower platen or moved to an open position as indicated in figure 2. The movable arm is pivoted around pivot 16 and the opening of the press is assisted by spring 17 connected to the end of the movable arm remote from the platen to counter the force oi gravity exerted on the platen.

An over-centre locking mechanism or arm generally designated by 18 is provided to hold the movable arm in the close position and the whole mechanism is operated by moving the locking arm operating handle 19. This arrangement allows rapid movement of the upper platen from the open position to the closed position in which the upper platen is in close proximity to the lower platen. In this position as the pressure is not being applied to the material between the upper platens the opening of the press is effected with minimal pressure applied to operating handle 19 to move the locking arm from its over-centre locked position to its released position.

Pressure applying means in the form of a hand operated screw is shown in figure 8. The force supplying means includes a pressure applying screw 25 having a head and a square threaded shaft. The shaft engages with the thread of a pressure applying boss 26 and the end of the screw bears against a pressure applying bearing 27. To facilitate turning the screw, a handle 19 shown in figures 1, 2 and 3 is fitted to the head of the screw 25. The pressure applying boss 26 may be bolted by means of through holes 28 to the upper platen mounting plate or may be formed as an integral part of the mounting plate 21.

The pressure bearing 27 bears upon a pressure plate 22 found adjacent to the upper platen mounting plate and is located between the mounting plate and the upper platen.

An upper platen support plate 23 is located between the upper platen and the pressure plate 22 and to which the upper platen 14 is mounted to allow the upper platen to be replaced or removed for repair etc. Between- the pressure plate 22 and the support plate 23 is disposed spring means 30. The spring means may be of any suitable type of spring including resiliently deformable plastics material sheet especially of the high density variety. However the preferred embodiment uses a plurality of the spring discs 31 illustrated in figures 4 and 5. These have the particular advantage that they are capable of exerting a high pressure and are of extremely low profile. If additional pressure is required this can be accommodated by combining a number of the spring discs 31 as illustrated in figures 6 and 7.The combination in figure 6 increases the pressure able to be applied to the spring and figure 7 illustrates how the spring can be adjusted to increase the movement which can be absorbed by the spring. A combination of figures 5 and 6 may be incorporated to increase the movement and increase the pressure at the same time.

Bolts 24 hold the platen support plate 23 to the platen mounting plate 21 to limit the amount of travel between these two plates and to provide a pretension to the spring means 30.

As the screw 25 is rotated it travels through the boss moving the pressure bearing 27 away from the boss which in turn applies pressure to the pressure plate moving the pressure plate away from the mounting plate 21. In use, material is placed on the lower platen with the upper platen in the open or raised position and handle 19 is brought down to close the press. In so doing the upper platen strikes the material placed on the lower platen and pressure is applied to the material placing a low tension on the spring means 30. In this position the bolts 24 are no longer bearing against the upper platen mounting plate 21.

As the handle 20 is turned, the screw 25 moves into the boss and moves the pressure plate 22 away from the mounting plate 21. This movement compresses the spring means 30 urging the support plate 23 and thus the upper platen 14, towards the lower platen 12.

The further the handle 20 is rotated the further the screw 25 moves through the boss 26 and the greater the pressure applied by the spring means 30 onto the support plate 23, as the springs are compressed between plates 22 and 23. Once the springs are totally compressed they act as spacers and are no longer capable of absorbing the regularities in the alignment between the upper and lower platen and the force supplied by the screw 25 is applied directly onto the platen. This situation is normally avoided where possible to allow for the misalignment between the upper and lower platens. These slight misalignments should be absorbed as the machines are not required to be of high precision.

As the range of movement required between the soft close contact and the hard pressure applying contact is small the rotation of the screw required to apply the necessary pressure and the necessary compression of the spring means 30 is also relatively small.

Sufficient movement which may be as small as 1/4 inch, can be obtained by appropriate design of the pressure applying screw and the length of the handle 20 can be chosen to provide the necessary mechanical advantage required to allow pressures of l.O to 2.0 and 22 kilograms per sq. centimeter to be readily obtainable by manual operation. Preferably, the angular rotation of the handle 20 is between 45" and 1800 and most preferably the desired pressure can be obtained by rotate the handle through only 90".

As mentioned previously when using this type of press in a textile fusing process it is desirable that the platens be heated and the platens may include within their construction a heater (not shown) to heat the platens to the desired temperature. Although the pressure applying mechanism is shown attached to the upper platen it could equally be fitted to the lower platen.

In an alternative embodiment not shown the pressure applying screw could be operated by an automatic mechanism such as electric motor. In one such embodiment two electric motors may be used in which one motor drives the platen at a high speed between the open position and the closed position. This arrangement does not requiring the manual over-centre locking mechanism for the movable arm and the movable arm or platen may be moved vertically rather than pivotably and a second motor may be used to apply high torque rotation movement to the pressure applying screw preferably at a lower speed.

Also, the movable platen may be operable between open and closed positions with the "fixed" platen being movable to the pressure applying position by means of the pressure applying screw mechanism.

Although the invention has been described with reference to a press for fusing inter lining, the mechanism of the invention may be used to provide presses for other purposes such as transfer printing, etc.

Claims (14)

1. A press having a fixed platen and a movable platen wherein the movable platen is brought into close contact with the fixed platen by operation of an over centre locking arm, and the movable platen is moved from the close contact to a pressure applying position by means of a pressure applying screw.

2. A press as defined in claim 1 wherein the pressure applying screw operated by a movement of a handle connected to the head of the screw means through an angular movement of between 45" and 180 .

3. A press as defined in claim 2 wherein the handle is approximately 12" long.

4. A press is defined in any one of the preceding claims wherein spring means are provided between the movable platen and a support frame connected to the pressure applying screw and the over-centre locking arm.

5. A press as defined in claim 4 wherein the spring means is a resiliently deformal plastics sheet.

6. A press as defined in claim 4 wherein the spring means is a plurality of disc washer.

7. A press is defined in any one of preceding claims wherein the press is used for fusing textiles in the garment industry and the platens contain heaters to fuse the textiles under pressure and heat.

8. A press is defined in any one of the preceding claims wherein a motor is arranged to drive the pressure applying screw means.

9. A press having a fixed platen and a movable platen wherein the movable platen is moved from an open position to a close contact position at a relatively high speed and wherein the movable platen is moved from close contact to pressure applying position at a lower speed.

10. A press as defined in claim 9 wherein the movable platen is moved by means of at least one electric motor driving a screw transport mechanism.

11. A press comprising at least one pair of platens wherein the platens of the or each pair are brought into close relative contact position with each other, and the platens are moved from the close contact position to a pressure applying position by means of a pressure applying screw means.

12. A press as defined in claim 11 wherein the position of the platens is controlled by an electric motor driven screw transport mechanism.

13. A press as defined in claim 11 or claim 12 wherein the pressure applying screw means includes an electric motor.

14. A press as substantially hereinbefore described in reference to the accompanying drawings.