US2766949A - Automatic sheet guide - Google Patents

Description

Oct. 16, 1956 s. w. WARNER AUTOMATIC SHEET GUIDE 3 Sheets-Sheet 1 Filed June 29, 1953 Oct. 1956 s. w. WARNER AUTOMATIC SHEET GUIDE 3 Sheets-Sheet 2 Filed June 29, 1953 Illllllllll lilllllllll-l lllll |l|| l\llll||l|lllll| .iilllllllsl .4, 53.5 1 333.3

iTl lllllllllll||1||lI|||||II-1| IIIIIIIIItIIIIII Oct. 16, 1956 s. w. WARNER 2,766,949

AUTOMATIC SHEET GUIDE Filed June 29, 1953 3 Sheets-Sheet 3 United States Patent AUTOMATIC SHEET GUIDE Sterling W Warner, Frede'rickshnrg, Va., ass'ignor to American Viscose Corporation, Philadelphia, Pa, a corporation of Delaware Application June 29, 1953,Serial-No. 364,789

'6'Claims. ((Jl.-24276)' This invention relates to web-control apparatus and, more particularly, to an improved device which more accuratel-y controls the register of a travelling sheet or web.

The primary object of the present invention is to provide a relatively simple, inexpensive mechanism for 'accurately controlling the lateral position of a travelling web-of material, for example, a sheet of cellophane A further object of the invention is 'to provide a combined vacuum and air travelling sheet control mechanism which is highly sensitive and quick-acting.

A further object of the invention is to provide a completely pneumatic control system 'for edge registry of travelling sheets.

Further objects will be apparent'from the specification and drawings in which Figure l he side view of a sheet-feeding apparatus incorporatingthe improved control system of the present invention;

Fi ure 2 'is a top seetionn view or the structure 'of Figar 1 as seen 'a'tlI -II.

Figure 5 is a section as seen at V-V of Figure 4; and Figure 6 is a-diagrarnmatic view showing howthe present invention is employed with synchronizing means to control'th'e registry at the unwind and rewind positions of 'a' single'machine.

The present invention comprises essentially the provision of an edge-detecting head or shoe having two slots therein which are'spaced in accordance with desired limits within which the travelling sheet must be-controlled. -A

vacuum connection is made to each of the slots in the shoe, and any change in the normal vacuum condition in each vacuum line 'actuat'es a vacuum diaphragm which is connected to a valve in an air pressure line. The main web-feeding carriage is moved transversely to the path of web travel by means of a reversible air motor connected to the two-way valve. This system eliminates all electrical'connections and is extremely sensitive and simple to install.

Referring now more particularly to the drawings, a roll 10 0f sheetmaterial S is mounted in trunnions 11 and 12 which are in turn supported on carriage 13. The carriage is movable transversely of the path of sheet feed on rails 14, 14, which support the carriage through axles 15 and 16 and flanged wheels 17, 17. A control shaft 249 is journaied in carriage 13 and has a threaded section which engages a stationary pillow block 21 secured to lower frame structure 22. Asial movement of shaft in carriage 13 is prevented by means of thrust collars 23 and 24 so that upon rotation of the shaft the carriage 13 is caused to roll in either direction along rails 14, 14. The outboard end of shaft 20 carries a sprocket 25 which is connected to an air motor 26 on the carriage by means of a chain 27. So that suitable manual adjustment of the carriage position can be made, a hand wheel 28 on stub ice 2 shaft 29 is capable of turning shaft 20 through a small Sprocket 3t! and chain'27. An idler take-up 31 for the chain may be mounted on the carriage between motor 26 and-sprocketfi asmay beneeded.

The sheet 5, as it unwinds from supply roll 1%],- feeds over a plurality of tensioning rolls 35, 36, 37 and 38-, All of these rolls are mounted in frame members as, 49 which likewise support a bracket ll-for thedetecting shoe assembly. l his shoe or .plate 42.:is provided with beveled side faces za and 42b facing across the sheet and-into the sheet as shown in Figures 3 and 4. The shoe is carried by a pipe 45 mounted in slide block 46 which 'is supported on a. stationary shaft 47. To provide for variations in the width of sheets being-run, lateral adjustment of the shoe 52 is eifected byturning. crank 48 which controls a shaft 49 threadedinto slide -block 45. A presser foot. 55 is mounted in a bracket 51 which is in turn in threaded engagement with a shaft 52 (Figure 2)- so that the ,presser foot moves simultaneously with the shoe 4'2. Qrank 58 is directly mounted on the shaft SZand controls ih'throug'h-chain 55.

The intermediate control mechanism mounted on the upper frame member "69' comprises a pair of vacuum diatphragms '61 and 621, both of which are connected to a source of vacuum "63 through conduits 6 -3, 55 and needle valves 66, 67. Vacuum chamber 61 connects with the inside slot 63 shoe ez'threugh vacuum conduit '69, and vacuum chamber '52 connects with the outer slot "73 through vacuum COnduit 'fi. The dia hra m rods 63a and 62a of vacuum chambers 61 and 62 actuate 'a'valve red 75 through avfalkih'g beam/7'6. A two wayp'ressure v'alv'e 77 directs air under pressure selectively 'tocon- :dilits 7s and '7l 'cenhectedto't1re airrrreter Conduit fi isconnect' d to a shitablc sourceerairtrnderpressure, not shown h '11. Valve rod 75 is Spring biase'd' at '81 and extends through the valve'so 'thatit can be "manually actuated by means of 'a lever 82 pivoted to the upper frame mei'nber'dii. When it is desired to dispense with the automatic operation of carriage '1 3,a latch 33 is swun toretain'l'ever' 32 midway ofits throw. A counterweight 84 on the latch-operating handle serves 'to maintain the latch in either a locked or' unlocked position.

As shown in Figure 2, the "sheet S is travelling across shoe 42 a proximately nit-away between the slots 68 and 7. Under these circumstances the vacuum in line '69 is retained sh that "thepi teh-rhh 61a of chamber 613s retracted. Since slot'79 is open, there is no'vacu'um in line 71. Therefore, the diaphragm in chamber-eats not actuated; Under these conditions the valve 77 does not permit air to how from conduit 80' into either conduit 73 M79. Sheurdthe sheet'Smove to'the' le ft, as seen in Figure 2, the slottiS- will'also be exposed thereby breaking -the vacuum in'c'ondu'it 6 9 and permitting spring 81 to move valve r'o'df7 5' downward as seen in Figure 2. This throws valve "77 to start air-motor 25 in the'proper direction'to'move carriage 13 to the right. As soon as slot 68 is covered by the "sheet the vacuum in chamber 61 returnsvalve rod 75 tothe closed'po'sitionythus s'to'ppingrnotor '26.

Should the sheet travel to the right, as seen in Figure 2, beyond the predetermined spacing between slots 68 and '70, then slot 7%) will be covered and vacuum built up in conduit 71 and chamber 62. This retracts rod 62:: to move valve rod 75 from the neutral position and introduce air from conduit 8% into conduit 73, thus starting motor 26 to move carriage 13 to the left. As soon as slot 7% is uncovered, the vacuum in line 71 is broken, thus releasing rod 62a and returning the valve rod 75 to the neutral position.

Should the sheet be nicked along its edge or should it travel too far towards the left, as seen in Figure 2, the beveled edges 42a and 42b of the shoe assist in returning shoe and are connected internally with their respective conduits 69 and 71 as shown in Figures 4 and 5.

When the apparatus of the present invention is employed in a single sheet-treating machine having a roll unwind mechanism at one end and a roll rewind mech anism at the opposite end, it is advantageous to synchronize the position of the detector shoes at the unwind and rewind endsrof the machine. In a cellophane-coating machine, for example, the distance between the unwind and the rewind roll is on the order of 40 ft. so that it is necessary to accurately guide the paper onto the rewind roll. For this purpose an edge detector mechanism at the rewind end of the machine is synchronized with the unwind roll carriage. As shown in Figure 6, a cord or cable 86 is secured to the detector shoe 42 which after passing over pulleys 87, 87 is fastened to one end of a piston-type valve 88. The opposite end of the valve is anchored to a stationary part of the frame through an extension spring 89. The detector mechanism at the rewind end of the machine may be of conventional construction and may include a single port shoe such as shown at 90. This shoe 90 is used to control the edge alignment of the rewind roll, in a manner well known in the art, as the web is received thereon. This detector shoe 90, at the rewind end of the machine, is controlled laterally by means of a threaded shaft 49a and slide block 46a mounted on shaft 47a in the same manner as previously described. The detector shoe 90, however, is connected to valve housing 91 by means of a chain or cable 92 passing over suitably arranged pulleys 93, 93. The opposite end of the valve housing 91 is secured to a stationary part of the frame by an extension spring 94 so that the housing is springloaded to be responsive to any laterally adjusted position of the detector shoe 90, and the valve 88 in the housing is likewise spring-loaded to be responsive to a laterally adjusted position of detector shoe 42. Air under pressure is admitted to the central part of the sleeve-like housing 91 through conduit 80a; When the position of detector shoe 42 is moved by turning crank 48, the valve will be displaced accordingly to open one of the ports 95 or 96 in accordance with the direction in which the shoe is moved. This admits air under pressure to one of the the position of valve housing 91 so that when the detector shoe 90 has moved an increment equal to the movement of shoe 42 the relative positions of the valve housing 91 and the valve 88 will be such that both ports 95 and 96 are closed with respect to conduit 80a.

Y conduits 97 or 98 which in turn operates a reversible A particular advantage of the present control system resides in the ability to utilize separate actuating means for the carriage as opposed to previous systems in which the carriage was actuated directly from the vacuum system associated with the edge-register device. The relatively low vacuum in shoe 42 can be on the order of seven inches of mercury, thus avoiding damage to the delicate sheet as well as the likelihood of inducing rupture of the sheet. With relatively high pressure air on the order of 40 p. s. i., it is entirely possible to obtain quick and effective movement of carriage 13 without using excessively large or complicated control structure.

' Having thus described my invention, I claim:

1. In edge registry control mechanism for travelling sheets, a pair of relatively low pressure pneumatic chambers, means associated with each of said chambers and movable in resonsc to pressure fluctuations in said chambers, a walking beam connected to each of said means, a valve rod pivoted to said walking beam, a two-way high pressure valve actuated by said valve rod, means for moving a supply roll of sheet material transversely of the/path of sheet material feed, a reversible pneumatic motor for operating said last-named means, a pair of high pressure conduits connecting the valve and the pneumatic motor, a detector shoe positioned adjacent the edge of the travelling sheet and having a pair of slots therein, one of said slots being normally covered by the sheet and the other being normally uncovered by the sheet, a low pressure conduit connecting said normally covered slot to one of the cham bers, a low pressure conduit connecting the normally uncovered slot to the other of said chambers, and a low pressure pneumatic connection to each of said conduits. 1

2. Apparatus in accordance with claim 1 in which the detector shoe is laterally adjustable with respect'to the edge of the travelling sheet. 7

3. Apparatus in accordance with claim 1 in which the valve rod is spring-loaded.

4. Apparatus in accordance with claim 3 having means for locking the valve rod in a neutral position. 7

5. Web-feeding mechanism having a web unwind station, a web rewind station, edge detector means at the unwind station for sensing the lateral position of the web, edge detector means at the rewind station for sensing the lateral position of the web, each of said detector means including a detector shoe adjacent the edge of the web, means for adjusting the lateral position of the detector shoe at the rewind station, a sring-biased fluid cylinder, means operatively connecting said spring-biased cylinder.

and one of said shoes, a spring-biased piston in said cylinder, means operatively connecting'said spring-biased piston with the other of saidshoes, and fluid conduits con-' meeting the cylinder and the adjusting means whereby the detector shoe at the rewind station is automatically adjusted in accordance with the movement of the detector shoe at the unwind station.

6. Apparatus in accordance with claim 5 having a manual adjustment for laterally controlling the position of the detector shoe at the unwind station.

References Cited in the file of this patent UNITED STATES PATENTS 1,113,637 Hulder Oct. 13, 1914 1,982,685' Muller Dec. 4, 1934 2,114,716 Kunzle Apr. 19, 1938 2,491,636 Amos Dec. 20, 1949 2,562,026 Fife July 24, 1951

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