US 3166172 A
Description (OCR text may contain errors)
Jan. 19, 1965 w. F. KELSEY ETAL MONITORING RIBBON THREAD THICKNESS AND STOP DEVICE Filed March 20, 1962 INVENTORS WINFIELD F. KELSEY ARTHUR L. LIBERTY vI u I II
ATTORNEY 3,166,172 7 MGNTTGRTNG RILEBQN THREAD THEQAIJEL JS AND STGP DEVEQE Winfield I Kelseyand L. Liberty, Easthanrpton,
Mass, to United Elastic Corporation, Easthamptnn, Mass, acorporation or'lviassaehusetts Filed Mar. 21?, 1%2, See. No. 183698 4 (iji. 192-127) This invention relates to improved mechanism for preventing the Winding of defective ribbons, particularly ribbonsof elastic threads loosely connected to each other 7 for shipment.
w i am l atented iam 19,196
exaggerated by the varying physical condition of the operator, for example if she comes to work tired the period of reasonably satisfactory gauging-skill will be 7 shorter. As a'result ribbons with defective sections This is a very-serious sometimes pass the inspection. matter because a ribbon with a defective spotcan cause interference with its use by the final customer, and cutting out and reconnectinga defective spot is-much more serious and time consuming and costly in the final use' than in the ribbon form. t
In spite of the human frailty which resultedin a cer- V tain proportion of defective ribbons this hasbeen the only method used. The cost of defective ribbons has Rubber threads have been made in the past by cutting a rubber sheet or frequently by cutting through a stack of rubber sheets to form a number of square threads which are then formed into ribbon for transportation. Serious problems have arisen with nonuniform or defective ribbons. This problem is particularly serious with rubber threads cut from a stack of rubber sheets, but can also arise with other threads in the form or" a ribbon, for example extruded elasticthread of rubber, spandex and the like. As the problem is particularly acute with ribbons of rubber threads cut from a stack of rubber sheets the problems arising and their solution by means of the present invention Will be described in connection with such-a ribbon of rubber threads, it being understood that the inventionis not broadly limited to ribbons of rubber thread, and is equally applicable to the detection and prevention of defective ribbons made. up from other thread forms.
When a ribbon is cut from a stack of sheets of rubber,
ting machines proceed at considerable speed and some times the cutting wheel may become slightly looseor may chatter sorthat it'does not always cut perfectly straight, that is to say at ri ht angles to the'surface of the stacked sheets.
on the opposite side of the cut, separated of course by the length of ribbonbetween the-two positions; While any substantial non-uniformity of ribbon thickness, from fiat face to flat face, is undesirable, thin spotsare particularly troublesome as they may constitute weaknesses in the final thread when the ribbon is used to produce elesticifabrics andthe like, the threads being normally The ribbon formed. is merely a convenient separated. and very economical way to transport long lengths of thread. v r p r it is customary to wind the ribbon, which may pass between guiding rolls onto drums and "back-wind onto spools or cartonsfor shipment. During the winding the for example a stack of 40 sheets, this is usually efifected When this occurs there will be a; thick spot on the ribbon with a'corresponding thin spot that precision is lost. s r r The present invention solvesthe problem by modifying the micrometer, providing the enlarged jaws with extended plates connecting to the micrometer screw, the
', plates'being at right angles to the'travel of the ribbon? been considered an unavoidable drawback, I
The present invention solve'sthe problem completely by substituting'a precision machine for the human fingers.
The machine does not get tired, does not lose, its sensitiveness, and can avoid the shipment of ribbons with defective portions. a machine, or-perhaps more correctly an attachment to a winding machine, ordinary micrometer calipersywere purchased, their jaws elongated by welding on exte'u' sions so that they could handle ribbons of the'desired width, and by attaching themicrometer to a pivoting member which, when it pivoted sufficiently, actuated a microswitchwhich through relays stopped the machine.
At first this simple machine operated beautifully and. the r problem appeared to be solved. After a few months, 1 v however, the machine failed. After runniugfor a short time'operation became erratic and unreliable. It wasf found atter considerable experiment that failures 'resuited from the development of some play in the microm eter jaws. Gbviously, of cours'epit is essential thatithe jaws remain parallel and that they be adjusted accurately so that there will be the right amount of friction," and/or wedging whenever a thick spot on theribbon passes. through. The jaws were set for a slight oversize, for
example a thousandth ofaninch or so, but when the jaws-began to develop play this precise dimension could no longer be maintained. The machine operatederratically and was therefore no better than the human operators it replaced. 7
Having found out that failures resulted from developmentfof play in the jaws: it might seem that thiscould be cured by using greatly oversized .jaws.v This, however, is notpractically possible because we are dealing f with a delicate gauging and so a comparatively'small' amount of friction must cause the micrometer and its framework to tilt and" actuate the switch. If the jaws are enormously oversized,'for example five to eight times, the weight of the whole ,instrumentbecomes so great Also these plates move in guides which are also plates withtheir wide dimensions at right angles to the platesconnecting the jaw's'to the micrometen, In this way the ribbon passes between thumb and finger of an operator. 7
She is supposed to sense the occurrence of a thick spot or thin spot as the ribbon passes between her fingers, and
to stop the Winding machine and cut out a defective sec tion when this occurs; This has created a' serious manufacturing problem. Theaccuracy of determining nonuniforrnity in the ribbon is often inadequate; A highly wide platesof-the jaws bear on an extended surface of 7 the guides and both members showed an extremely high I rigidity to bending in thedirection of their large dimension. Since these two directions'are atright ang es toeach] other a stiffness results which isiequal or greater than that obtainable with a micrometerof enormously greater cross-section which is far too heavy for practical usei" a, The plates andguides. atright angles'to each other solved f the problem completely and the gaugesoperated reliably and continuously for long periods of time. 'At the sarne time the dimensions and hence weights of the micrometer When it was first attempted to designl jmoderate cost. ments of the present invention which make it practical caliper are not increased at all or not significantly, and so sensitivity remains at a maximum.
While the important thing is an accurate gauge which will operate for many months on end reliably it is also a further advantage that the plates and guides are simple with a resulting saving in labor costs.
mechanical structures which can be produced at very In fact the gauge with the improvehardly costs any more than :the gauges which operated only for amonth or two and then failed. Often animproved result is obtained only at considerable additional cost for construction, and in this respect the presentinvention is'rather unusual that the great improvement which makes the device practical is obtained without any significant offsetting additional cost.
Another advantage of the present invention is that.
it is not necessary to build micrometers of specialdesign.
Ordinary commercial micrometers are easily adaptedby welding or brazing the plates and guides, and it is thus s is to use a single pivoting point and a number of bars 7 I It will be seen that the member has extensions 14 and which clamp onto the micrometer caliper proper, using a conventional clamping screw 16. It is thus possible to use commercial 1 micrometers without having to build them, and if after long service. the caliper develops'play, a new one can be substituted easily.
Sometimes'it is necessary to vary the friction at which the member 5 will turn. This is easily effected by providing a series of pivot points 29, one of which'is shown, in the, framework 6, and moving out the bar 7 which passes throughthe member 5 and is'clamped by'a clamping screw 17. In this way the leverage represented by the bar and the shoe 8 is varied and the machine can be set for different degrees of friction. An even simpler way with different weights on the end. Such a weight is shown at 18 clamped on to the bar 7 through a rivet or screw 19. This possibility of varying the friction at which the gauge turns off thewinding machine, which not an eS sential part of the broad invention, is an advantageous re- The gauge is fastened to the framework of an ordinary ribbon-winding machine, and since the rest of the machine is not in any way changed .it'is not shown. The ribbon of cut rubber thread is shown at 1 and' moves generally from left to right in. the direction of the arrow.
. It passes through two extended jaws 2 and 3 which are set slightly oversize so that the ribbon of the proper size in passing through. the jaws creates negligible friction.
The two jaws have weldedinto them flat plates 11 Whichf connect them to' an'ordinary micrometer caliper 4. The plates 11 are welded into the two jaws of the micrometer and are shown in more detail in FIG. 2. This caliper in 7 turn is rigidly attached to a member 5 which is pivoted in a framework 6 attached to or part of, the winding machine, by means of the pivot 13; A bar 7 is' clamped to-the memberS .andis terminated. by a shoe 8. This shoe bears on a spring-pressed switch plunger 9 of a micro-switch 10. 'The flat plates 11 are. moved by the micrometer'screw in a guidev slot between two plates 12 whichin'turn are fastened to a portion of'the member 5 clamped around the micrometer caliper; The lower jaw 22. of the caliper to which theplate 11 fromthe extension jaw 3 is welded moves in. the, ordinary manner by turning the'caliper micrometer. The plate 11 slides in the guide slot between the two plates 12.
In operation when the jaws have been accurately set to the desired spacing the ribbon passing through does not create enough friction and the jaws and member" 5 remain in .a verticalposition. The spring-pressed plunger 9 is compressed and the switch 10 is'therefore, of course, closed. If a'thick spot in the ribbon comes along the friction rises rapidly, the jaws move tothe right; and
this causes the member 5 to turn on its pivot 13 in the direction shown by thecurved arrow. This raises the shoe 8 until finallyit moves oi the plunger 9 which then is urged by its spring outwardly, the switch 10 is opened turning on the motor 21 and'the machine stops.
urged inwardly, v V V 4. .A machine according to claim 3 in which the bar finement which is included in a preferred modification of the invention. 1
The invention is primarily useful for gauging ribbons, but of course it can be adapted for gauging other shapes by a suitable contouring of the micrometer jaws;
1. In a machine for winding a continuous length of material of predetermined thickness the improvement which comprises (a) a gauging element attached to the winding machine and provided with jaws positioned so that the moving 1 material passes between them,
(b) the jaws having micrometric adjusting means to adjust the spacing of the jaws a predetermined openmg, V (c) relatively wide plates connecting each jaw to the micrometric adjusting means, 7 7 (d) a guide slot composed of two relatively wide and thin plates having their wide dimensions at right angles to the plates connecting the jaws to the micrometric means, the latterfplates sliding in the guide slot formed between the second plates,
(e)'piv0t means permitting the jaws to move the gauging element in a circle when'the friction of the ma terial passes through the jaws exceeds a predetermined value, and V "(f) switching means actuated by pivoting of the gauging member to stop the winding machine. 2. A machine according to claim 1 in which the switching means is a microswitch with a spring-pressed plunger and'the actuation means is a bar swung by the pivoting of the gauging member and provided with a face contact- 'ing'the's'witch plunger and having an extent such that it is moved out. of contact with the switch plunger at a predetermined degree of pivoting.
-3. A machine according to claim 2 in which the surfacecontacting the plunger is provided with edges bevelled away from the plunger so that when the gauging member is restored to its original position the switch plunger is 1 and surface engaging the switch plunger extend horizontal- The'operator'then examines the ribbon'and cuts. out
the thick, andfin the case of spirally cut ribbon the thin 7 spot, which rnay'be a foot or more distant. The ribbon ends are then fusedor otherwise fastened together, the caliper and jaws 2 and 3 moved to the vertical position ofithe member, 5 which closes, the switch 10, and the v machine. startsfup' It will be notedthat the operator does not have to be constantly-gauging the ribbon with her" fingers, but only has to examine it minutely when thecaliper has moved and has stopped the machine.
operator to. supervise more than one winding machine Complete reliability is, obtained and it is possible for one ly and their weight determines the friction at which the machine is stopped.
:Refer'encies Cited in'the file of thisipatent UNITED STATES PATENTS .7
- Scholfield Sept.
. 1,077,818 'Eagar 1 Nov. 4,1913.
1,905,259 Abbott j Apr. .25, 1933 2,370,187 Pechy Feb. 27, 1945 2,434,864 Powell Jan. 20, .1948