FR2612504A2 - METHOD AND DEVICE FOR PLACING FABRIC ON A CUTTING TABLE - Google Patents

Abstract

Method for setting a length of fabric (4) flat on a cutting table (1) having a non-slipping surface providing for the permanent an accurate positioning of the fabric, characterized in that a slipping sheet (3) is placed on the cutting table (1), in that the fabric is accurately positioned on said sheet (3), in that the fabric is fixed by side presser means (51, 52) and radial presser means (50) which are independently controlled, and in that the slipping sheet (3) is removed without displacing the fabric.

Description

2 612504

  Method and device for placing fabric on a cutting table It is recalled that patent application FR-A-86.04102 teaches inter alia the use of a sliding sheet to facilitate the placement of a fabric coupon on a cutting table. The upper side of the cutting table having a honeycomb structure has a highly abrasive surface

  since it appears as a succession of sharp edges.

  The abrasive effect is particularly strong on the part of the sliding sheet having cutouts as taught in the aforementioned application. This abrasive effect is much more marked in the implementation phase of the sliding sheet, on the one hand because of the speed, on the other hand because of the orientation of the

cuts.

  In fact, for reasons of productivity, it is very beneficial to minimize the time for setting up the sliding sheet, and therefore to operate at high speed. On the other hand, the problem does not arise for the removal of the slippery sheet after placement of the fabric coupons because a slow speed and a

  weak acceleration is necessary so that the fabric does not move.

  The present invention provides a solution to avoid friction of the sliding sheet on the upper face of the cutting table during the phase of placing the sliding sheet. A main characteristic of the invention is a controlled vertical movement of the cutting table, at least for

the honeycomb part.

  The present invention can be followed with reference to the figures which show: a vertical section of the cutting table,

and the slippery sheet.

  Figure 1 shows a sheet in progress and a

low table;

  Figure 2 shows a fully unrolled sheet and a coffee table; Figure 3 shows a fully unrolled sheet and a high table and Figure 4 shows a fully unrolled sheet

and a high-variant table.

  The actual cutting table consists of a metal frame and a parallel honeycomb structure. (item 1). A frame (2) guides the movements of the table. An articulated X (3) resting on a horizontal crosspiece

  (4) allows to impose a vertical displacement on the table (1).

  In Figure 1, 1'X is in the folded position (item 3)

  while in Figure 3, it is in the unfolded position (item 5).

  The deformations of the X are controlled by known means such as

than a screw.

  For the installation of the sliding sheet, originally wound on the roller (6), we start by putting the cutting table in the low position (figure 1) and we unroll the sheet pulling by the roller (8) on the fasteners (7) of the sheet. This is done until the sheet (9) is in

  place between the two rollers (6) and (8) (figure 2).

  To make the position of the sheet (9) stand out better, its thickness has been deliberately exaggerated very strongly in the figures. We then go back, by action on the X, the table 1, in the high position, so that the upper face of the table is as close as possible to the sheet (9). In Figure 3, there is shown the sheet (9) and the table (1) in contact, which is

obviously the borderline case.

  If the tension on the sheet (9) - by means of the rollers (6) and (7) in particular - is large enough for the deflection of said sheet to be negligible, it is advantageous not to have contact but rather to leave a clearance of less than 3 mm and preferably close to 1 mm between the sheet (9) and the upper surface of the table (1). When we operate with a thin sheet (9), we will not be able to impose a large tension and,

  in this case, there will be contact between the sheet and the table.

  There is shown in Figure 4 a variant for the vertical displacement of the table without showing the sliding sheet and the rollers. On a horizontal crossbar (10) are placed jacks such as (11) and (12) two in number for example on the

  figure 4 -. The rods (13) and (15) bear under the table (1).

  The pipes (17) and (18), joined to the pipe (16), make it possible to supply the two jacks in synchronism with high pressure liquid and thus to move the table. We can

  consider placing a larger number of cylinders if desired.

  The following operations continue as in patent application FR-A86.04102. It is advantageous, when the fabric is placed on the cutting table and is held by the pressers, to remove the slippery sheet carefully so as not to entrain the fabric and move it. A variable speed motor will be used for rewinding the sliding sheet. We can in particular impose on the engine a speed-up program (from zero speed) to have low acceleration and low speed. This avoids the entrainment of the fabric or the formation of the fold on the fabric and reduces the friction of the sliding sheet on the cutting table so

reduces the wear of said sheet.

Claims (4)

  1. Method according to claim 1 of the main patent, characterized in that the cutting table (1) can be moved, at the cutting station, with a controlled vertical movement, between a   low position and a so-called high working position.   2. Method according to claim 1, characterized in that the cutting table (1) at the cutting station is put in the low position, that the sliding sheet is unwound (9) and that the table is then brought cutout (1) high position, so that the distance between said sheet (9) and the upper face of the table is very small or zero, less than 3 mm and preferably close to 1 mm.   3. Method according to claims 1 and 2, characterized in   that the vertical displacements of the cutting table (1) are obtained by opening (or closing) an X (3) controlled by a known means such as a screw.   4. Method according to claims 1 and 2, characterized in   that the vertical movements of the cutting table (1) are controlled by a plurality of jacks (11) and (12) supported on a   horizontal crosspiece (4) and placed under the cutting table (1).