US 3616770 A
Description (OCR text may contain errors)
Nov. 2, 1971 s. c. BLYTHER ETAL 3,616,710
MANUFACTURE OF ELASTICATED GARMENTS Filed Jan. 13, 1970 United States Patent 3,616,770 MANUFACTURE OF ELASTICATED GARMENTS Stanley Charles Blyther, Bassett, and Colin Philip Jones, London, England, assignor to LR Industries Limited, London, England Filed Jan. 13, 1970, Ser. No. 2,498 Claims priority, application Great Britain, Jan. 15, 1969, 2,360/ 69 Int. Cl. D05b 23/00 U.S. Cl. 112121.26 5 Claims ABSTRACT OF THE DISCLOSURE A continuous elastic band is drawn by feed rollers in stretched condition across a work surface and is sewn to garments on the work surface. A pilot photo-cell detects the trailing edge of a garment just before it enters the feed rollers and produces a signal which sets a second photo-electric device. A pneumatically operated cutting device positioned immediately after the feed rollers cuts the elastic hand between garments when the second photo-electric device which is adjacent the cutter blade detects a gap between garments. The cutting device will not operate unless the second photo-electric device has been set by a signal from the pilot photo-cell.
This invention relates to apparatus for separating articles secured to a band more particularly to apparatus for separating garments to which a band of elastic has been sewn.
For example, in the manufacture of disposable panties an elastic waist band is included by sewing the band and the garment material together with the band in a stretched condition so that the band and the material lie flat against each other. If desired a hem to enclose the elastic band may be produced at the same time.
This sewing operation is carried out using a standard sewing machine, a continuous band of elastic material being fed from a reel under tension and the band and the garment material being drawn through the sewing machine by suitable feed means, conveniently a pair of toothed pressure rollers, which also serve to maintain the tension in the elastic.
Upon completion of the sewing operation it is necessary to cut the elastic band between successive articles. It is not possible to cut the elastic between the articles until after the articles and the elastic band emerge from the feed means, at which time the tension in the elastic is released and the gaps between adjacent articles, which during the sewing operation may have been about 2 inches, are reduced to about A".
In practice it would be unsatisfactory merely to sense the articles photoelectrically at the cutting station, since the sewn material emerging from the feed means often wanders side ways considerably, which could cause cuts in the middle of a garment.
The present invention therefore provides in addition pilot photo-electric sensing means positioned ahead of the feed means where the elastic band is still under tension and arranged to render the main photo-electric sensing means effective only when a gap between successive articles is sensed by the pilot sensing means. Since the two sensing means have predetermined relative positions the arrangement can be such that cutting of the elastic band occurs only at the gaps between successive articles. Cuts cannot be made inadvertently in the middle of an article.
The present invention provides apparatus for separating articles secured to an attached band comprising feed means for advancing a band with articles secured thereto,
a cutting device positioned after the feed means for cutting the band between articles, first photoelectric sensing means positioned before the feed means for sensing the trailing edge of an article, and second photoelectric sensing means for sensing gaps between articles passing the cutting device, and arranged to operate the cutting device only after the last photoelectric sensing means has sensed the trailing edge of the article determining the gap sensed by the second photoelectric sensing means.
Apparatus according to the invention will now be described, by way of example only, with reference to the accompanying drawing, which illustrates schematically apparatus for attaching elastic to articles.
Articles 1 of non-woven fibre of open structure are fed along a horizontal work surface 2 in spaced-apart succession. A continuous elastic band 3 is fed from a supply reel 4 and superimposed in a stretched condition on the upper surface of an article 1 on the work surface 2 to form eventually part of an elasticated waist band on the article. A tensioning device 5 maintains tension in the band 3 stretched over the articles 1 being sewn.
The articles 1 and the superimposed band 3 are passed through a conventional sewing machine 6 in which the stretched band 3 is sewn to the fabric of the articles 1 and, at the same time, a hem is formed enclosing the stretched band 3 where it passes over the articles 1.
Feed means comprising a pair of toothed pressure rollers 7 are arranged immediately following the sewing machine 6 and are driven in the direction of the arrows. The rollers 7 grip the band 3 and maintain the tension therein as the band passes through the sewing machine 6 and also serve to pull the 'band 3 and the articles 1 through the sewing machine 6.
Beyond the pressure rollers 7 the tension in the band 3 is released. A cutting device having a vertically movable cutter blade 8 is arranged immediately following the rollers 7 for cutting the elastic band 3 between successive articles 1 and thereby separating the elasticated articles. The cutter blade '8 is displaceable by means of a pneumatic double-acting actuator 9.
The blade actuator 9 is controlled by a photoelectric device. Two photocells are arranged above the work surface 2: a pilot photocell P1 is arranged immediately in front of the pressure rollers 7 and a main photocell P2 is arranged immediately following the rollers 7. The distance between the photocells is of the order of 1 /2". The photocells P1, P2 are arranged to receive light from a suitable source (not shown) after reflection from the articles on the work surface 2. The work surface 2 below the photocells is matt black.
The photocells P1, P2 are connected to respective photo-electric relay units 11, 12 for example units of the type PS104M manufactured by Hird Brown Limited. The units 11, 12 are arranged to provide output signals When the light entering the respective photocells P1, P2 is interrupted: thus the cells are responsive to the trailing edge of an article 1.
The pilot photocell relay unit 11 is connected to a relay A having associated normally-open contacts A1, A2: contacts A1 are hold-in contacts and form part of a hold-in circuit for the relay A, the hold-in circuit being completed by a normally-closed microswitch MSI. Contacts A2 are included in an energising line 14 interconnecting the main photocell relay unit 12 and an operating solenoid 15 for a solenoid-operated pneumatic pilot valve V1.
The pilot valve V1 is a spring-biassed spool valve having two positions corresponding respectively to energisation and de-energisation of the solenoid 15, in which a compressed air supply is respectively connected to and cut ofif from an actuator control valve V2 which is also operable by means of a solenoid 16. The valve V2 also has two positions which, when an air supply is connected thereto by the pilot valve V1, correspond respectively to upward and downward movement respectively of the cutter actuator 9.
The microswitch M51 is operable by a pressure responsive device 17 which is connected to one of the outputs of the control valve V2 and which is effective to open the microswitch MS1 when that output is under pressure, the arrangement being such that the microswitch M51 is opened when the cutter actuator 9 is operative to raise the cutter blade 8.
A second, normally open, microswitch M52 is operatively associated with the cutter blade 8 and is closed when the blade has descended fully. This microswitch M52 is connected in an energisation line 18 for the operating solenoid 16 of the control valve V2.
The arrangement operates as follows. When the leading edge of an article 1 passes the pilot photocell P1 the light reflected into the latter is increased and the signal from photocell P1 is broken, causing relay A to deenergise. The relay de-energising also causes the circuit from relay unit 12 through solenoid 15 to be broken. Valve V1 spring resets and pilots valve V2 back to position ready for cutting.
When the end of the article passes photocell P1 an output signal is supplied by relay unit 11 to relay A, the coil of which is energised and then locked in by the closure of the contacts A1. The closures of contacts A2 completes the line between the main photocell P2 and solenoid valve 15 so that when the trailing edge of the article passes the main photocell P2 the output provided by 12 energises the solenoid valve 15.
The pilot valve V1 is thereupon operated to supply compressed air to the control valve V2. The valve V2 supplies compressed air to the actuator 9 in a sense to move the cutter blade 8 downwardly. The blade 8 is so positioned in relation to the photocell P2 that, when the latter detects an edge of an article 1, the blade 8 is directly above a gap between that article 1 and the article immediately following it, so that the descending blade 8 severs the band 3 at said gap.
On reaching the bottom of its descending stroke the blade 8 causes the microswitch MS2 to close, thereby completing an energising circuit for the solenoid 16. The valve V2 is moved into its other state by the solenoid 16 and reverses the connections to the actuator 9, retracting the blade 8. Simultaneously, the microswitch M51 is opened by the pressure responsive device 17, thereby interrupting the hold-in circuit for the relay A. Consequently, if. an article 1 is present beneath the photocell P1, or as soon as an article comes into position beneath the photocell P1, the relay A is de-energised, causing contacts A1 and A2 to open, and permitting the valve V1 to reset to its inoperative position under its spring return. In so doing, the valve V1 supplies a pneumatic resetting signal to the control valve V2, returning the latter to its initial position, and thereby causing the microswitch MS1 to reset (i.e. close). The arrangement is then ready to undergo a further cycle of operations to separate the next succeeding article 1 from the band 3.
In effect the photocells P1, P2 are responsive to the difference in reflectance between articles and the matt black work surface, and thus to the gaps between successive articles 1. This arrangement is particularly suitable where the articles comprise materialofopen structure such as non-woven fibre as used in disposable garments. However, with conventional fabric garments direct photo-electric sensing may be employed, in which the articles pass between a light source and a photocell to vary the light falling on the photocell. The main photocell P is rendered operable to control the operation of the cutting device under control of the pilot photocell P1, which senses the gaps between the articles 1 when the elastic band 3 is still under tension. Thus irregularities resulting from the release of tension in the band 3 before the latter reaches the cutting device to not impair the accurate operation of the cutting device.
It will be appreciated that alternative control and actuator means, other than the pneumatic means illustrated, may be employed.
1. Apparatus for separating articles secured to a band comprising feed means for advancing a band with articles secured thereto, a cutting device positioned after said feed means for cutting said band between articles, first photoelectric sensing means positioned before said feed means for sensing the trailing edge of an article, second photoelectric sensing means for sensing gaps between articles passing the said cutting device and arranged to Operate the said cutting device only after the said first photoelectric sensing means has sensed the trailing edge of the article determining the gap sensed by the said second photoelectric sensing means; and a holding relay in which the said first photoelectric sensing means is arranged to operate the said relay, said relay making a circuit between the second photoelectric sensing means and the cutting device, and being held until the cutting device has operated.
2. Apparatus according to claim 1 comprising sewing means for sewing articles to the continuous elastic band, and means for applying tension to said band as it is being fed through said sewing means for said feed means.
3. Apparatus according to claim 1, including a work surface over which the said band is advanced by the said feed means in which the said photoelectric sensing means are arranged to receive light reflected from the articles and said work surface.
4. Apparatus according to claim 3 in which the work surface is matt black.
5. Apparatus according to claim 1 in which the cutting device is pneumatically operated.
References Cited UNITED STATES PATENTS 2,050,316 8/1936 Gulliksen 83'75 2,681,019 6/1954 Liebowitz ll2121.26 2,685,664 8/1954 Visconti 83-365 3,329,113 7/1964 Lewis et a1. 112-130 JAMES R. BOLER, Primary Examiner US. Cl. X.R.