US2871012A - Display apparatus to allow examination of a fast-moving continuous web - Google Patents

Description

Jan. 27, 1959 P. R. PRICE 2,871,012 Y APPARATUS TO L g DISPLA A L W EXAM'N TION OF A FAST-MOVING CON INUOUS B Filed Aug. 13, 1956 5 Sheets-Sheet 1 P. R. PRICE Jan. '27, 1959 P. R. PRICE DISPLAY APPARAT OF A FAST-M 2,871,012 ALLOW EXAMINATION CONTINUOUS WEB 5 Sheets-Sheet 2 US TO OVINQ Filed Aug. 15, 1956 0mm Nam vww fill EVER P R. PR CE 7% J ML gr My; 7?

H R E w PW wa NM Q mm SEQ m? R P WM mm /W x Q l- M m W w m, RE {WI} 1.. w T L L WWW Raw mL mw m M L 1 1. TI W lill M I HI \UH NN l 1 l l l I l -u q H L M L m V 1\U $w Jan. 27, 1959 Filed Aug 15 1956 United States Patent DISPLAY APPARATUS TO ALLOW EXAMINATION OF A FAST-MOVING CONTINUOUS WEB Peter Ralph Price, London, England, assignor of one-third to George Edmond Brackenbury Abel], and one-third to Donald William Tilley, London, England Application August 13, 1956, Serial No. 603,755 Claims priority, application Great Britain August 18, 1955 12 Claims. (CL 271-2.3)

In any process for the production or treatment of material in continuous form, such as a web, and in which visual examination of details of quality is desirable, difficulty, is experienced if the web is travelling at a very high speed, and this invention relates to apparatus of the kind which provides a temporary retardation of the rate of travel of the web at the viewing zone.

produced. In some casesof printing and textile process ing, there is no cutting stage, the product being re-reeled. In all these and similar cases it would assist the control of quality if a monitoring unit is placed after each processing unit. j I I I t This invention refers to apparatus of the general type that operates to arrange a continuous web in corrugated form as it enters the apparatus and to restore it to its original form as it leaves, such as is used for the drying of material in web form.

According to this invention, in a display apparatus of,

the kind described, the web traverses the viewing zone at a uniform speed less than the speed at which the web passes through the apparatus. In other words, the web is not alternatively retarded and accelerated in the viewing zone. I

An advantage provided by a display apparatus according to this invention is that a direct view of the printed matter is obtained without optical aids and the printed matter is in view for a sufli cient length of time without recourse to stroboscopic efiects.

According to another feature of this invention, means are provided to continuously effect corrugation of the web as it enters, and means to continuously restore the web to its original form as it leaves the apparatus, the viewing-zone being situated where the Web is in its corrugated form. Pereferably the display apparatus com prises, two continuous carrier-chain-systems so disposed and driven as to provide a lay on one system moving parallel with and at the same speed as a lay on the other, web-guiding bars or rollers carried on said chains, the rollers on atleast one chain being supported thereon by arms projecting from that chain so that in the said lay, the rollers supported bythe said arms enter between the bars on the other; chain to define a corrugated path for the web. I w

According to another feature of this invention thearms, on at least one chain, carrying the web-guiding rollers are pivotally mounted on that chain.

' According to yet another feature of this invention the said pivotally mounted arms engage a cam sur facejso shaped as to cause the rollers onthatchain to enter between the rollers on the other chain and to be intersected therewith in the sections of the systems where one chain moves parallel with and at the same speed as the other. The rates at which the web is delivered to, and withdrawn from the apparatus, are equal and constant, and,

the web passes through the apparatus under tension, so that essentially the length of web contained within the apparatus is constant, and the cams are so arranged as to ensure this.

The rollers in at least one system may be mounted in pairs on the said arms.

According to another feature of this invention the rollers are rotated on their own axes so that their surfaces move at substantially the same speed as that with which the Web passes them. It is preferred to drive the rollers by means of continuous chains or belts, the said chains or belts travelling, over a section of their paths, along a path of substantially the same shape as that which the web follows in the apparatus.

The operation of a display apparatus: and a practical construction thereof will now be described with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic view of a display apparatus showing one side of the machine;

Figure 2 is a part view in section, along the line 22 of Figure 3, of a display apparatus;

Figure 3 is a view in section along the line 33 of Figure 2;

Figure 4 is a part plan view.

Referring first to Figure l, the display apparatus comprises two carrier-chain- systems 10, 11. The upper chain system 10 is constituted by a pair of continuous carrierchains 12 spaced apart laterally on similar coaxial sprocket wheels 13. The lower chain system 11 is similarly constituted by a pair of chains 14 on sprocket wheels 15.

The two carrier-chain- systems 10, 11 are disposed one directly above the other with the horizontal lays 16 of the upper chain-system 10 lying parallel with and spaced from the horizontal lays 17 of the lower system 11. Rollers 18 are provided in the lower system 11 and each extends between and is supported at each end by the pair of chains 14. On the upper system 10 the rollers 19 are mounted on the free ends of arms 20 pivoted on the chains 12 and the rollers 19 are each associated with a pair of rollers on the lower chain system 11.

A pair of continuous cam-surfaces 21 are mounted alongside each of the upper chains to engage the said pivoted arms 20 and control the position of these arms. The sprockets are so rotated as to cause the chains 12 and 14 in the horizontal lays 16 and 17 respectively to move at the same speed and in the same direction. As the rollers 19 and 18 approach the horizontal lays 16 and 17 respectively the parts 22 of the cam-surfaces 21 cause the rollers 19 of the upper chain-system 10 each to descend and thus enter between the pair of rollers of The shape of the cam-surfaces is indicated in Figure 1 but may be of any other suitable shape.

A web of material 26 issuing at constant speed from a machine, such as a printing press, enters the display apparatus between the horizontal lays of each chain system, is looped by the rollers 18 and 19 and is maintained in this form until it is restored to its original form as it emerges from between the ends of the horizontal Patented Jan. 27, 1959 esnma lays of the chain-systems. The viewing-zone is the middle part of the parallel lays of chain and in this zone the plane lengths 27 of the web supported by the said pairs of rollers on the lower chain-system, are visible.

The chains in the horizontal'lays 16'and 1 7 move in the same direction as the web 26and'thusthe plane lengths 2-7--of"the corrugationsrnove ata speed'which is less than that at which the web enters the apparatus and these tops can therefore be examined; The displayed matter thus passes the examiner in a spacedseries travelling at uniform speed'and the matter which is not displayed is looped out of sight underneath.

The speed and direction of movement of the chains in the horizontal lays 16'and'17; relative to the incoming web speed, may be so chosen that the displayed partsof the plane lengths of the web, either move backwards, are stationary or'even move forwards relatively to the examiner; the displayed portions of the web may be sta tionary relative to the examiner by making the web move backwards relatively to the rollers.

The cam surfaces are so shaped as to cause the sum of the lengths of all the lengthening loops to increase at a constant rate, and the sum of the lengths of all the shortening loops to decrease at a constant rate and so that the rates of increase and; decrease are equal.

In a practical construction of displaying apparatus (see Figures 2, 3 and 4) according to. this invention the lower carrier-chain-systemcomprises a pain of chains each constituted bylinks 30- pivotally connected at- 31 to adjacent links. Each linkhas an upstanding extension 32' and a pairo-f rollers 33 is carried between the. free ends of each pair of extensions 32, one extension being'oneach chain. Rods 34 are providedwhichextend between the chains. and each end thereof provides the pivo-talconnect-ionbetweenthe-links 30; The ends 35 of the rods 34:. extend beyondthe links 30 and'each carry a roller wheel 36. Theseroller wheels 36 each engage, in the horizontal lays of the chains (of which a part is-shown in Fig ure 2:), with the upperplane surfaces. of a track 37 se-.

cured to the frame of the apparatus and thus support the. horizontal lays-of the. chain. A second planesurface 38 lying below and at an acute angle to the saidupper plane.

surface is. provided on each track 37. Further roller wheels 39=aresecured by means of brackets 4am some of; the links 30. Theseroller wheels 39 each engage with a surface. 38 of a track 37 thereby maintaining the.

ofa guide-track 44formedintegrallywith the frame 52 Further roller wheels 45 are secured of the apparatus. 7 by means ofbrackets 46 to some of the links 41. These roller wheels. 45each engage with the lower surface of a guide 44.

Each spindle 47 has secured thereto a roller-arm 48 v and a cam-,follower-arm 49; the roller-arm 48 and the cam-follower-arm 49 together constitute a two-armed lever. The roller-arm 48 is disposed on the innerend of,

the spindle 47 and the cam-follower-arrn 49 ontheouter end. A roller 50is carried between the free ends of the two rller-arms-48, one on each chain, the two chains being so disposed relative to one another that the rollerarms 48on one chain are directly opposite the rollerarms on the other chain.

Two identical pairs of cam sutff ge eachpain constituted; by a groove 51 in the side frames 5210f the display apparatus, are provided along the length of the ppa s- E h amr ql wst t ta y m un e .on.

he-free and; of, a. am-t olloner-arra 49,v engages ith carrier-chain moves along on the track 44 the cam-followers 53 are constrained to follow the path of the grooves 51. A web 54 is entrained between and looped by the rollers as hereinbefore described, and plane lengths 60 are traversed past a viewing zone.

The spacing between two adjacent rollers 33 each mounted on-an adjacent link 30 is made as small as pra c-. ticable. Where the lower carrier-chain passes round sprocket wheels (not shown) the spacing between these rollers isincreased and thus the increase is sufficient to allow the roller 50 of the chain-system to enter; between the said adjacent rollers 33; The cam surfaces 51 are so shapedas tocause the rollers 50 to enter between rollers 33 and to return therefrom whilst the chain-links 30, carrying these rollers, are following an arcuate' path.

The cam surfaces 51 are parallel with the tracks 37 and 44 along most of the length of the parallel lays of chain and at each end thereof are curved away from the tracks 37 towards the tracks 44. The curved parts of the cam surfaces 51 are so shaped as to cause the sum of the length of allthe lengthening loops to increase at a constant rate,'and'the sum of the lengths of all the shortening loops to decrease at a constant rate such that the.

rates of increase and decrease are equal. A second consideration in the shaping of the cam surfaces 51 is that the accelerations and'decelerations of the rollers 33 and 50 should be as low as practicable.

The shape of the cam surfaces 51 is merely indicated in Figure 2" and the precise shape thereof'is determined by the requirements hereinbefore set forth.

Itis desirable to drivethe web-guiding-rollers 33am!- Stlabout their axes so'thattheirsurfaces eachmove-with the same speed as that; of theweb 54 passing over them.

The web may then be maintained at substantially constant tensionas -itpasses through the apparatus and ita second continuous driving-chain 57 meshes with thoseof the upper system. In addition an identical sprocket 58 is mountedon each roller 33 and 50. The sprockets 58 on one chain-system are arranged to be aligned with thesprockets-55 on the other chain-system so thatwhile the rollers are travelling along the horizontal lays the sprockets on their axes mesh with both the continuous driving-chains. The driving-chains are thus constrained to follow the path of thetweb and may each bedriven, by a further chain meshing with the sprockets 55 or 58 in a section of the carrier-chains outside the said horizon-.. tal lays, so that the surface speed of each roller is equal to the speed of the web passing that roller.

Alternatively double chains may be used in place ofthe. single. chains 56 and 57 which permit a driving.

sprocket to engage with the second half of the chain.;

The form of presentationof the web obtained with the display apparatus hereinbefore described has .the,

advantage, over known kinds. of display apparatus, that theeye can follow and dwell on doubtful parts of the, web, or scan each part as it'comes into view. Also, since the displays travel at constant speed, flicker andother effects tiring to the eyes are obviated.

A further advantage of this form of display appagatps is that sub-standard sections-of the, web may be easily marked by the examiner in any convenient manner,- and, these sections may be automatically rejected after leaving: the, display apparatus, by using suitable deyicesopen te by; he mark n I In nothe rra gem e q lers f pp r. sys- One tern are mounted in pairs on the said pivoted arms. 'Ihese rollers are thus mounted closely adjacent each other in pairs, and the rollers of the lower system are mounted in groups of three to co-oeprate with the pairs ofrollers in the upper chain-system. The section of the web which may be examined lies between the end rollers of each group of three. p a

To obtain alow speed of travel of the displayed web, it is desirable to make the space between the displayed plane lengths of web as small as possible. To attain this it is necessary to make, the diameter of all therollers 33 and 50 as small as possible. Alternate arms, supporting the rollers on the lower system may be pivoted to allow, temporarily, an increase of space between the Although the apparatus has been describedhaving the,

displayed plane lengths of the web passing therethrough horizontally, the apparatus may be turned so that the displayed plane lengths pass through in a vertical plane.

I claim:

1. Display apparatus for traversing a web of material past a viewing zone comprising a first means for revealing at the viewing zone in succession plane lengths of the web comprising a first continuous sprocket-driven carrier-chain, guide-rollers journalled at the ends of arms extending from the links of said chain, the rollers being arranged in pairs to support and reveal at the viewing zone successive plane lengths of web and a second means operative during the period of time between the appearance at and disappearance from the viewing zone of any part of a plane length of web for moving said plane length past the viewing zone at a substantially constant speed'which is less than the speed at which the web enters the apparatus, for maintaining a substantially constant tension in the web and for delivering the web from the apparatus at substantially the same speed at which it enters the apparatus, said second means comprising a second continuous sprocket-driven carrier-chain, second guide-rollers journalled at the ends of first arms of twoarmed levers which are pivotally mounted on said second chain, said second chain having a lay adjacent" and parallel to a lay of the said first carrier-chain, means, operable when the carrier-chains are driven to cause the said second guide-rollers to enter between the said pairs of first guide-rollers to loop the web.

2. Display apparatus according to claim 1 wherein each of the guide-rollers has co-axially mounted on it two sprockets, one at each end of the guide-rollers.

3. Display apparatus according to claim 2 wherein the guide-rollers are rotated by continuous drive-chains meshing with the said sprockets, which drive-chains travel over a section of their paths parallel to the path of the web and rotate each roller so that its surface speed is the same as the speed of the web passing over it.

4. Displayapparatus for traversing a web of printed material past a viewing zone comprising in combination, a first sprocket-driven continuous carrier-chain comprising links pivotally connected end to end, an arm extending outwardly from each of the said links, a pair of guide-rollers carried on each of the said arms, extending transversely to the path of movement of the said carrierchain and spaced apart along the said path, a second sprocket-driven continuous carrier-chain having a lay parallel with and adjacent to a lay of the first carrierchain, a bell-crank lever on each link of said second carrier chain having a roller-arm and a cam-follower arm,

' ing along the said parallel lays of the two carrier-chains,

and means for feeding a web of paper between said parallel lays of the carrier chains, supported by the pairs of guide-rollers on the said first carrier-chain and in position for pushing between those rollers by the bell-crank carried rollers thereby to form speed reducing loops in theweb. i

5. Display apparatus according to claim 4 wherein each of the said guide-rollers has co-axially mounted on it two sprockets, one at each end of the guide-roller and wherein the sprockets on like ends of the guide-rollers carried by the said first carrier-chain mesh continuously with a first continuous drive-chain and the sprockets on the opposite ends of the guide-rollers carried by the said first carrier-chain mesh intermittently with a second continuous drive-chain, which second drive-chain meshes continuously with the sprockets on like ends of the guiderollers carried by the said second carrier-chain and the sprockets on the opposite ends of the guide-rollers car ried by the said second carrier-chain mesh intermittently with the said first drive-chain, which intermittent meshing occurs in the region of the said adjacent lays where the said drive chains follow a path substantially the same as that followed by the web of printed material, and wherein means are provided for driving at least one of the said drive-chains.

6. Display apparatus according to claim 4 wherein each of the said guide-rollers has co-axially mounted on it two sprockets, one at each end of the guide-roller and wherein the sprockets on like ends of the guide-rollers carried by the said first carrier-chain mesh continuously with a first continuous drive-chain and the sprockets on the opposite ends of the guide-rollers carried by the said first carrier-chain mesh intermittently with a second continuous drive-chain, which second drive-chain meshes continuously with the sprockets on like ends of the guiderollers carried by the said second carrier-chain and the sprockets on the opposite ends of the guide-rollers carried by the said second carrier-chain mesh intermittently with the said first drive-chain, which intermittent meshing occurs in the region of the said adjacent lays where the said drive chains follow a path substantially the same as that followed by the web of printed material, and wherein means are provided for driving at least one of the said drive-chains.

7. In a web manipulating machine of the kind in which a web is caused to travel under tension at a uniform high overall speed, means for locally reducing the web speed at a viewing station to enable successive planar sections of the web to be examined visually, comprising an endess succession of spaced web-support devices each embodying two such supports spaced apart along the length of the succession to support between them a planar section of the web, means for moving the succession past the viewing station in the direction of web movement and adjacent one face of the web, an endless succession of web diverting members, means for moving the diverting mem bers in the direction of web movement adjacent the other face of the web and in staggered relation with the web-support devices and means for moving the diverting members into the spaces between the support devices as they approach the viewing station, thereby to push the web between the support devices to form a succession of loops in the web alternating with a succession of plane surfaces and means for withdrawing the diverting members from the spaces after leaving the viewing station.

8. In a web manipulating machine, web-speed reducing means as claimed in claim 7 in which the means for moving the diverting means into the spaces and for with-V rawi g m. t f mv ar operative t ubstan y the sameeff ective ,qveralLloog farming and loop releasing peed.- whe eby he verall on n h W em ins.

nst nL n w hrrn n p a h n we speed. educing rneansas clairn edjin claim? in which thelrnea pi moving the diverting members into the spaces, are operated; p eg essiv ly nd a c p. p ducing pe ds, uc that the sections of the web travel past the viwing station on, thesupport; devices at substantially the rateof travel of 'the; succ ession of support devices;

References Cited in the file of'this patent UNIIED ST TES EN S 13753006 Hurxthal Apr; 15, 1930 2,513,777

Andre July 4; 195.0

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