GB2241964A

GB2241964A - Sewing machine guide

Info

Publication number: GB2241964A
Application number: GB9005757A
Authority: GB
Inventors: Chi Tak Li
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-03-14
Filing date: 1990-03-14
Publication date: 1991-09-18
Also published as: GB9005757D0

Abstract

The present invention provides a sewing machine comprising means for adding reinforcing stitching along a pre-sewn seam between pieces of material, said machine comprising: a base plate 1 across which the pieces of material comprising the pre-sewn seam are pulled by a traction mechanism; a traction mechanism located below the base plate and projecting up through slots 3 in the base plate for advancing the material containing the seam continuously across the base plate; a stitching mechanism located above the base plate for inserting the reinforcing stitching into said seam as the material is advanced across the base plate by the traction mechanism; and a guide 2 positioned in advance of the stitching mechanism for guiding the material across the base plate and into the stitching mechanism wherein the guide includes means 6 for biassing the pre-sewn seam to one side relative to the direction of advance of the material through the guide so that the seam emerges from the guide consistently on the same side of the centre line of the guide. <IMAGE>

Description

IMPROVEMENTS IN AND RELATING TO SEWING MACHINES The present invention relates to sewing machines.

When garments are made from pieces of material joined edge to edge, it is usual to join the edges of two pieces in two stages, the first stage comprising a single line of stitching to secure the two pieces of material together to form a seam, and the second stage comprising adding one or more lines of reinforcing stitching. When garments are produced on an industrial scale, special purpose apparatus is provided for applying the reinforcing stitching.

One known apparatus for use in adding the reinforcing stitching along a seam comprises (a) a guide into which one end of the seam may be introduced; (b) a base plate generally below the guide and along which the pieces of material are pulled; (c) a traction mechanism generally below the base plate and projecting up through slots in the base plate for pulling the seam continuously through the guide and along the base plate; and (d) a stitching mechanism located generally-above the base plate for applying the reinforcing stitching.

A disadvantage with the above described apparatus is that the reinforcing stitching is not always parallel to the securing stitching, but may instead be of curved or sinusoidal shape relative to the securing stitching. Typically, when two reinforcing stitches are added, one on each side of the securing stitch, the two reinforcing stitches will lie parallel to one another but will oscillate slightly relative to the joining stitch. In these cases the stitches are unsightly and must be redone, or alternatively the garment may have to be sold at a reduced price, or in extreme cases the garment must be discarded altogether. The lack of parallelism arises because as the seam emerges from the guide onto the base plate, the seam may fold to one side or the other, under one piece of joined material or under the other piece of joined material, sometimes to the right and sometimes to the left.Along the entire length of a particular seam, part of the length of the seam may fold to the right and part may fold to the left.

The invention provides apparatus of the type described characterized in that the guide includes a biassing means for biassing the seam to one side so that the seam emerges from the guide consistently on the same side.

The invention will now be described more particularly with reference to the accompanying drawings which show, by way of example only, one construction of apparatus according to the invention. In the drawings : Figure 1 is a perspective view of two pieces of material which have been joined by a securing stitch to form a seam, and to which reinforcing stitching is to be added; Figure 2 is a plan view of the guide and base plate; and Figure 3 is a perspective view of the guide, shown on a larger scale.

Referring in more detail to Figures 1 and 2, Figure 1 shows two pieces of material 101, 102 which have been joined by means of a line of securing stitching 103 to form a seam generally designated 104. Two lines of reinforcing stitching are to be added, one line of reinforcing stitching immediately above the securing stitching 103, and the other line of reinforcing stitching immediately below the securing stitching 103. The direction in which the seam 104 will be drawn through the apparatus is indicated by the arrow "A".The apparatus comprises a base plate 1 along which the two pieces of material 101,102 are pulled, a guide 2 at the front end of the base plate for receiving the seam 104 disposed in the configuration shown in Figure 1. a traction mechanism (not shown) which is located beneath the base plate and operates upwardly through the slots 3 in the base plate to move the material along the base plate, a sewing mechanism (not shown) above the base plate which operates downwardly, with the sewing needles passing throught the slots 4 in the base plate.

Referring in more detail to Figure 3, the guide 2 according to the invention is assymmetric, and comprises a recess or rebate 5 on the left hand side thereof and a projection or step 6 (indicated by dashed lines) on the right hand side thereof. As a result, when the seam 104 is introduced in the disposition shown in Figure 1, the seam will emerge, on a consistent basis, under the left hand piece of material 101 as indicated by arrow "B" and not under the right hand piece of material 102.

Referring back to Figure 2, the base plate 1 also includes a recess 7 at one side of the left hand side slot 4, to facilitate passage of the folded seam 104.

Finally, the lower face of the sewing mechanism (not shown) may also be assymmetric, to ensure that the seam emerges under the left hand piece of material (not shown).

Claims

1. A sewing machine comprising means for adding reinforcing stitching along a pre-sewn seam between pieces of material, said machine comprising: (a) a base plate across which the pieces of material comprising the pre-sewn seam are pulled by a traction mechanism; (b) a traction mechanism located below the base plate and projecting up through slots in the base plate for advancing the material containing the seam continuously across the base plate; (c) a stitching mechanism located above the base plate for inserting the reinforcing stitching into said seam as the material is advanced across the base plate by the traction mechanism; and (d) a guide positioned in advance of the stitching mechanism for guiding the material across the base plate and into the stitching mechanism wherein the guide includes means for biassing the pre-sewn seam to one side relative to the direction of advance of the material through the guide so that the seam emerges from the guide consistently on the same side of the centre line of the guide.

2. A sewing machine according to claim 1, wherein the biassing means comprises a recess on one side of the guide and a projection on the other side thereof.

3. A sewing machine according to claim 1, comprising a guide means substantially as herein described with reference to and as shown in the accompanying drawings.