US3367294A - Tufting machines pattern control arrangement - Google Patents

Description

Feb. 6, 1968 R. ELLISON ET TUFTING MACHINES PATTERN CONTROL ARRANGEMENT Filed April 29, 1966 2 Sheets-Shem 1 Kalli/1L0 ELL/s o/v IV INVENTORS JO/l/V PR/TCHHRD n IVOIPIW/MI P/c/rLEs Feb. 6, 1968 R. ELLISON ET AL 3,367,294

TUF'IING VACHINES PATTERN CONTROL ARRANGEMENT Filed April 29, 1966 2 Sheets-Shem 2 "F l G. 27'

RO ALD ELLISON JOHN PR/Tc/MRD fM b mvzmogs NORMA/V PIC/(LES BY W9-m United States Patent 3,367,294 TUFTHNG MACHKNES PATTERN CONTROL ARRANGEMENT Ronald Ellison, John Pritchard, and Norman Pickles,

Blackburn, England, assignors to Ellison Tufting Machinery Limited, a British company Filed Apr. 29, 1966, Ser. No. 546,226

1 Claim. (Cl. 112-79) ABSTRACT OF THE DISCLOSURE An improved pattern control for tufting machines of the type which is effective to cause pattern changes during tufting operation, the improvement being circuitry that correlates the occurrence of any pattern change to the loop-forming movements of the tufting needles and is effective to insure the completion of loops before a change in pattern is permitted.

The present invention concerns multiple needle tufting machines of the type use in making carpets or like fabrics, wherein a pattern is formed in the work by selectively commanding the formation of pile loops of normal or reduced height respectively, by means such as a pattern drum.

The object of the invention is to ensure a more faith ful reproduction of the original design and greater consistency of appearance both as between one patterned piece and another and as between one pattern repeat and another repeat on the same piece.

According to the present invention the pile loop height changes to be executed are determined by pattern control means such as a pattern drum, and are synchronised by further means with the machine cycle to change the pattern being formed in the work at a predetermined phase of the movement of the needles.

In prior tuft-ing machines, although the patterning element was driven at a speed related to the speed of the Work advance, e.g. by driving a patterning cylinder from the main spindle of the tufting machine at a predetermined fraction of its speed, no attempt was made to corelate the precise instant of pattern changing to the momentary position of any needle, with the result that marginal conditions arose where a change of pattern occurred, possibly resulting in an incomplete reduction in loop length. The present invention, however, in precisely defining the change relative to the phase of loop formation, results in a much sharper reproduction of the design by accurately timing each and every pattern change.

Timing of pattern changes is effected by a cam rotated by the shaft driving the needles, the cam actuating contacts or a photo-electric or magnetic pick-up. This actuation applies an energising potential to all of the pattern controlling devices of the machine simultaneously, for a time sufficient for the needles to make one loop each. During the time between loop formations, the said control devices are rendered inactive, so that pattern movements relative to the pick-up devices are ineffective to operate the control devices.

Timing setting may be assisted by the provision of a stroboscopic illumination of one of the mechanical parts, e.g. the tufting needle bar, to define its position at the instant of pattern changing command.

Reference should now be made to the accompanying drawings in which:

FIGURE 1 shows a section of part of a tufting machine; and

FIGURE 2 is a schematic of the control mechanism for determining the length of loop formation.

3,367,294 Patented Feb. 6, 1968 The tufting machine itself is constructed upon a frame 12 which carries a needle bar 15 located in a bushing 16 for vertical reciprocation. Each machine consists of a large number of needles, and these needles 22 are reciproca-ted by means of a crank and eccentric 14, 13, all the cranks and eccentrics being driven from a common shaft 11. Each needle feeds a yarn 2 in a series of long or short loops into a backing fabric 3 which is fed constantly past the row of needles, the length of loops formed being determined electrically from a pattern.

The eccentric 13 carries a cam surface or switch-actuating projection 17 which during rotation makes contact with and closes a pair of contacts 18. These contacts are carried by means of an adjustable clip 19 on a curved bracket 20 mounted on the frame of the machine, the position of the contacts relative to the cam being adjustable by means of the screw 21.

The pattern effect of the needles is determined by means of a drum P, illustrated in FIGURE 2. This drum which is rotated at a rate proportional to the rate of feed of backing material past the needles, carries a pattern which is illuminated, there being a plurality of photo-cell pick-up devices 61 located near the pattern. Each photocell has an individual amplifier 59, the output of which operates a relay 57. This relay actuates a pneumatic valve 55 which via a regulator 53 applies air presure when the valve is opened to a cylinder 52 having a piston 51. The latter carries a brake shoe 50 which acts on one or more yarns to restrict their loop length when the brake is applied. It therefore follows that control of individual loops or groups of loops can be effected from a pattern photoelectrically.

Since however the needle reciprocation is rapid and the movement of the pattern drum relative to the photocells is low, it may happen that a pattern change occurs under a photo-cell when the needles have executed a partial movement. This might cause the production of only partially completed loop lengths of either long or short lengths. By provision of the contacts 1 8, which are connected to all the amplifiers 59 in parallel via the lead 4, it can be ensured that no action by a photo-cell 61 can energise its amplifier 59 unless contacts 18 are closed. This ensures that the needles must be in the correct position for a brake change before such change is effected. In this way .it can be ensured that all the loops, either of the long or short variety, are completed when a pattern change is commanded.

Although the invention has been described in connection with the use of contacts o-peated mechanically from a cam, the said contacts may be replaced by a photo-cell or magnetic pick-up device, in which case the output of the said device would be connected to lead 4 via a suitable amplifier.

The means outlined above ensure that if a photo-cell changes its condition, i.e. from braking to non'braking or vice vers-a, before the contacts 18 close, this change of condition is ineffective to operate the brake concerned, betore a predetermined time. If however the contacts 18 close whilst a photo-cell is in a pattern-commanding condition, as when receiving light, the pattern changes which would ordinarily follow and which would ordinarily operate the brake associated with the photo-cell in question is prevented from occurring during mid-loop formation. To achieve this we incorporate a delay circuit in the amplifier 59 so that if the photo-cell 61 is, for example, receiving light from a portion of the pattern when the contacts 18 close, then the circuit of the amplifier 59 remains unaltered during the remainder of stitch formation, even though the pattern changes from light to dark meanwhile. As an alternative to this method, the amplifier 59 may be provided with a flip flop, the position of which is determined in the main by the degree of photo-cell energisation. The condition of the flip flop however remains fore a predetermined time. If however the contacts 18 even if the condition of the photocell changes meanwhile.

Whilst our invention has been described with reference to a cam-operated contact, it is clear that the said cam could carry a light-reflecting spot or magnet, and that a signal derived for the spot or magnet could be used for synchronisation instead of one from a contact.

We claim:

1. In combination, a tufting machine for making a tufted material comprising tufting needles, a drive shaft means operatively arranged to actuate said tufting needles through loop-forming movement so as to normally form loops of a comparatively long length, loop-length control means including a brake shoe operatively effective to selectively restrict loop length so as to correspondingly selectively form loops of a short length, a pattern control including loop-length changing means operatively arranged to control the operation of said brake shoe to provide a predetermined pattern of said long and short loops in said tufted material, an energiz-ation circuit for said pattern control including a normally open switch operatively effective to correspondingly normally maintain said looplength changing means of said pattern control inelfective, and switch-closing means arranged at a predetermined location on said drive shaft means for movement through a path effective to cause the closing of said normally open switch to thereby complete said energization circuit and operate said loop length changing means of said pattern control, said predetermined location of said switch-closing means being correlated to the loop-forming movement of said tufting needles so as to complete the formation of said loops preparatory to any change in length thereof.

References Cited UNITED STATES PATENTS 2,862,465 12/1958 Card ll2-79.6 2,989,014 6/ 196 1 Dedmon 1l279 3,075,481 1/1963 Stratton lv-l 2-79 3,089,442 5/1963 Short 11279 3,103,187 9/51963' Hammel 11279' 3,112,717 12/ 1963 Hamilton ll2-79 3,172, 3 80 3/1965 Boyles ll279 3,203,378 8/1965 Dedmon 1l279 3,272,163 9/1966 Erwin 112-79 HERBERT F. ROSS, Examiner.

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