This invention relates to a fabric production machine and to a method of marking fabric. The objective of the invention is to simplify the detection of fabric distortion that may arise during the processing of fabric after it leaves the fabric production machine.

In the manufacture of clothing from fabric, woven or otherwise, it is now common to use very sophisticated automatic techniques in the laying out and cutting of fabrics. Often, for example, many layers of fabric are cut simultaneously at one pass of an automatically programmed band saw or the like device. Naturally, for such an operation to be successful, any design or pattern on the fabrics must be aligned exactly so that each cut piece of fabric is identical. This requires much finer tolerances on the part of the fabric finisher to ensure that the finished fabric is free from bowing, skewing or check size variation. Often, this can result in additional processing by the finisher if it is discovered that the tolerances of the finished fabric are unacceptable to the end user.

The invention seeks to provide a method and apparatus for reducing this problem by enabling the dimensions of the fabric to be monitored throughout processing so that a far more accurate check may be kept on variations on the fabric during finishing and the necessary preventative or corrective actions can be taken.

According to the present invention we provide a fabric production machine having marking apparatus mounted so as to be capable of marking fabric before the fabric leaves the machine, the marking apparatus at least one comprising _L marking pen and means responsive to predetermined signals for moving the marking pen into contact with the fabric.

According to a further aspect of theinvention we provide a method which comprises making marks on a fabric before the fabric leaves the fabric production machine, the marks being made by a marking pen contacting the fabric in response to predetermined signals such that the marks have an accurately known predetermined relationship one to another so that .distortions in the fabric can be monitored throughout subsequent processing thereof.

When the production machine is a loom, and the fabric is a woven fabric, it is preferred that the marks are made as close as possible to the cloth fell line, i.e. the point of fabric construction, so that the fabric is marked before any distortion has developed. The marks are conveniently made on either or both of the fabric selvedges as these are not used in the finished product, and it is preferred that marks are applied simultaneously to both selvedges. Thus, by subsequently ensuring that successive sets of marks are maintained opposite one another throughout finishing, the fabric will be free from distortion and can be presented with confidence to the eventual user.

Conveniently the means responsive to said predetermined signals is a solenoid means mounted on the machine and operative to move the pen. Any suitable solenoid arrangement, and arrangement linking the solenoid to the pen may be used, and the pen may be of any convenient form, for example one of the commercially available pens that are used for marking fabric.

In order that the invention may be better understood embodiments thereof will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:-

• Figure 1 is a schematic view of the delivery end of a loom equipped with marking apparatus; and
• Figure 2 is an elevational view of an alternative embodiment of marking apparatus.

Referring now to Figure 1 there is shown the delivery end of a loom generally indicated at 1, the loom producing a woven fabric 2 delivered from the loom, the fabric having selvedges 3 and 4. Respective side frame members 5 and 6 of the loom each have a bracket 7,8 secured thereto by bolts such as 9 or by other suitable securing means. Each of the brackets 7,8 supports solenoid means 10,11, each solenoid means having an associated marking pen the tips12,13 of which normally lie slightly above the respective selvedges 3 and 4. Each of the solenoid means 10 and 11 can be actuated by an electrical signal on lines 14, 15 respectively, the signals being supplied simultaneously from a control unit schematically shown as 16. On supply of such a signal the pen tip 12 or 13 is moved into contact with the fabric selvedge runing below it. The two solenoid means and associated pens are located as close as possible to the cloth fell line so that the marks are made as early as possible before significant distortion of the fabric is possible.

In operation the solenoids are energized simultaneously so that marks are produced on the selvedges exactly opposite one another. The control unit 16 may form part of the overall control unit for the loom, or may be geared to the running of the loom so that signals are sent to the solenoids at intervals such that the marks made on the fabric are always a set distance apart on the fabric. Alternatively, the solenoids may be controlled independently of the running of the loom and controlled by a timing device so that marks are made at fixed intervals. In this case the distances between adjacent marks along the selvedges may vary.

In either arrangement, during finishing,the finisher can easily monitor these sets of marks and identify variations in finishing where distortion occurs and take the necessary preventative or corrective action.

The solenoid units 10 and 11 that hold and move the marking pens may be of any suitable form and their detailed construction does not form part of the invention. In one embodiment the pencil may be held in the hollow movable core of the solenoid means as suggested in Figure 1. In an alternative embodiment shown in Figure 2 the fabric marking pen may be releasably held by a clip 21 in an essentially tubular holder 22, such that the marking tip 24 of the pen protrudes from the bottom of the holder 22. The holder 22 is slidably mounted on a support 25 which may be bolted to a bracket on the loom through a bolt hole 26. The support 25 also carries a solenoid 28 capable of pivoting a bell crank lever 29 about a pivot 30 also secured to the support. An arm 31 of the bell crank lever engages between projections 32 on the side of the tubuler holder so that pivotal movement of the arm can move the holder downwardly or upwardly as indicated by the arrow in Figure 2. Downward movement moves the marking tip 24 into contact with fabric passing thereunder.

Although particularly described in the context of a loom, other forms of fabric production machines, for example knitting machines, may be provided with marking apparatus capable of marking the fabric before the fabric leaves the machine. In such machines the marking apparatus is again preferably positioned as close as possible to the point of fabric construction, and marks are desirably made at corresponding locations at each side of a width of fabric. The marks may thus be used for monitoring distortion during subsequent processing, and/or for other purposes such as marking lengths of fabric for subsequent cutting.

Solenoids having adequate power tend to be rather bulky and this can cause difficulties in locating the nib of the pen close to the fell line. The problem varies according to the construction of the fabric making machine. However, where the problem does exist, various methods can be employed to alleviate it. For example, in some situations the solenoid can be inclined slightly, away from the obtruding part of the machine. Alternatively, the core of the solenoid can be provided with an extension bearing the pen-so as to enable the solenoid to be positioned above the obtruding part of the machine in such a way that the narrower pen portion can project downward through the machine so the nib has access to the fell line.