US3396887A - Vacuum control for moving sheets - Google Patents

Vacuum control for moving sheets Download PDF

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Publication number
US3396887A
US3396887A US534703A US53470366A US3396887A US 3396887 A US3396887 A US 3396887A US 534703 A US534703 A US 534703A US 53470366 A US53470366 A US 53470366A US 3396887 A US3396887 A US 3396887A
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US
United States
Prior art keywords
sheet
vacuum
film
moving
sheets
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US534703A
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English (en)
Inventor
Bade Rudolf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WR Grace and Co
Original Assignee
WR Grace and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by WR Grace and Co filed Critical WR Grace and Co
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Publication of US3396887A publication Critical patent/US3396887A/en
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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
    • D21G9/00—Other accessories for paper-making machines
    • D21G9/0009—Paper-making control systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D7/00—Producing flat articles, e.g. films or sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H23/00—Registering, tensioning, smoothing or guiding webs
    • B65H23/04—Registering, tensioning, smoothing or guiding webs longitudinally
    • B65H23/24—Registering, tensioning, smoothing or guiding webs longitudinally by fluid action, e.g. to retard the running web
    • B65H23/245—Suction retarders
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06C—FINISHING, DRESSING, TENTERING OR STRETCHING TEXTILE FABRICS
    • D06C3/00—Stretching, tentering or spreading textile fabrics; Producing elasticity in textile fabrics
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C71/00—After-treatment of articles without altering their shape; Apparatus therefor
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06C—FINISHING, DRESSING, TENTERING OR STRETCHING TEXTILE FABRICS
    • D06C2700/00—Finishing or decoration of textile materials, except for bleaching, dyeing, printing, mercerising, washing or fulling
    • D06C2700/10—Guides or expanders for finishing

Definitions

  • ABSTRACT OF THE DISCLOSURE This invention relates to a device and a process for controlling moving sheets. In one aspect, the invention relates to controlling the speed and optionally the stretching or straining of moving sheets which are relatively impermeable to gases.
  • Another object of the invention is to provide method and apparatus for controlling the speed of moving sheets or webs.
  • Yet another object is to provide method and apparatus for stretching webs.
  • the web is pulled over the stationary member (by any suitable driving force) and the vacuum applied through the opening in the stationary member is increased to a value sufficient to cause a stretching of the Web.
  • the device disclosed herein is stationary. There are no moving parts. The number of holes and position thereof is such that all holes are sealed from the ambient atmosphere by the moving film.
  • the holes are positioned in a lower portion of a channel or recess in the surface of the stationary member so that the film does not actually contact the holes but is drawn part way into the channel by the applied vacuum. This assists greatly in adjusting speed because the film surface exposed to the vacuum is much greater than would be the case where the film passes directly over the holes.
  • the sheet is passed over a stationary guide surface which is plane or convex transverse to the direction of motion, especially a closed hollow cylinder, and is provided with one or several ports connected commonly via one or several regulating means with suction lines.
  • a stationary guide surface which is plane or convex transverse to the direction of motion, especially a closed hollow cylinder, and is provided with one or several ports connected commonly via one or several regulating means with suction lines.
  • the moving sheet can be strained or stretched, if desired.
  • the degree of stretching is preferably controlled via the vacuum at the suction ports by an automatic mechanism measuring the speed of the sheet or the distance of marks provided on the sheet.
  • the brake effect of the device according to the invention is based on the fact that the moving sheet is pressed against the guide surface by the vacuum at the suction ports and slowed down by the resulting friction.
  • the sheet is suitably guided in such a way that it covers all suction ports and thus seals them against loss of vacuum.
  • the brake power is dependent on the degree of vacuum and in addition on the size and number of the suction ports in the guide surface as well as on the characteristics of the sheet material, i.e., especially on its gas permeability and flexibility.
  • automatic or hand-operated valves connected at one end with the atmosphere and consisting preferably of three-way valves are provided in the suction line.
  • the present invention provides a number of advantages over the roll brakes previously used.
  • the full subpressure is not reached suddenly but with a short time lag so that the brake effect on the moving sheet is not sudden and sharp.
  • a smooth and careful speed reduction is possible, which is especially important with sensitive materials which tend to tear under strong stress.
  • an extraordinarily accurate and precise control of the brake effect is possible by regulating the subpressure at the suction ports.
  • this is possible in an especially simple manner since for this purpose only a normal regulating valve is required which can alternatively be operated by hand or automatically.
  • the regulating means i.e., generally a regulating valve, is the only moving part associated with the novel controlling device so that the device itself is notsubject to any wearing and is thus unusually re-j 1 liable.
  • FIGURE 1 is a perspective view, partlyin section, of an embodiment of the controlling and braking device
  • FIGURE 5 is a diagrammatic view of the sheet motion according to one example wherein the. sheet is strainedand controlled according to this invention at twopoints;
  • this channel has a step-like cross section.
  • the sheet isonly drawn into the upper enlarged portion 8 of the channel'3so that there- 4 below, achannel-shaped hollow space 9'is formed which is connected via the suction ports 7 with the suction line I and thus'provides 'a uniform vacuum.
  • FIGURE 6 is a diagrammatic view of the. sheet motion according to another example wherein an? automatically. controlled stretching of the sheet is obtained by means i of a device according to the invention.
  • a closed" hollow cylinder 1 is used as a guide surface.
  • Thehollowy cylinder 1 is providcdin the area contacting asheet 4.
  • a vacuum-creating device e.g., a vacuum pump .(not shown).
  • the brake effect can only be obtained with practically gasimpermeable materials, e.g., plastic films.
  • the brake effect can be very precisely controlled in a wide range by a corresponding regulation of the vacuum.
  • FIGURE la represents a modification of the device of FIGURE 1 wherein two stationary guide members are employed in series, each having at least one channel with holes in the bottom portion thereof. Except for the addition of a to the numeral, the numerals identify elements similar to those in FIGURE 1.
  • the top element 2 is rotatable, but 1 and 2a are fixed.
  • stationary guide member l' has 2 channels with bore holes while guide members 2a has one channel 3'; all channels being in direct contact with the film so as to prevent loss of pressure;
  • each of 1' and 2a are connected by conduits 5a and 5b to a vacuum pump.
  • FIGURE 2 shows a section A--A through the device of FIGURE 1. It can be seen that due to the guidance under the deflection elements 2, the sheet 4 closely engages a substantial part of the cylinder surface and thus seals the suction ports against the atmosphere.
  • the guide surface is provided with a recessed channel3 having one or more slot-shaped or circular suction ports 7.
  • the lowest point of the channel 3 isprovided with.
  • the device in FIGURE 4 comprises a plane guide surface 10 which is provided with several lines ofsuction ports 11 arranged diagonally to the direction of motion.
  • the sheet 4 is pressed against the. guide surface 10 by a great number of suctionports and is subject to the guide surface 10 and is subject to a particularly strong brake effect, especially if'a vacuum pump with high suction capacity is used.
  • FIGURE 5 a sheet is fed from a supply roll to a processing machine. Itfrequently occurs that I the" sheet is not drawn off continuously with uniform 1 speed but discontinuously in accordance with the operating cycles of the machine. Due to its inertia, the heavy no pullf is applied to the sheet 24. Since it would lead supply roll has the tendency to continue to rotate when i to sagging or fluttering of the sheet, this must be slowed down behind the roll 20. According to the invention, this is achieved by passing the sheet over a deflection roll 22 and from there around a hollow cylinderZl having suction ports in the area of contact.
  • the sheet 24 can run only when a pull overcoming the brake effect is applied in the direction indicated by the arrow.
  • a second device 23 corresponding to the device 21 is provided directly before the pulling device 27 and serves for passing the sheet tautly and without fluttering and wrinkling into the driving rolls.
  • the control of the vacuum in the hollow cylinders 21 and 23 can be effected separately or in common. This to brake the film more or less and to stretch it, if required, in order to achieve an accurate superprinting of the various colors.
  • the control of this braking or stretching is generally effected by means of photoelectric cells responding to metering marks on the film surface.
  • control of the exact stretching is performed by a photoelectric cell which records during passage of the film sheet whether the film now corresponds exactly to the dimension required by the machine. If this is not the case, the stretching force is continued until the exact dimension is obtained whereupon the stretching force is interrupted by the photocell.
  • a photoelectric cell which records during passage of the film sheet whether the film now corresponds exactly to the dimension required by the machine. If this is not the case, the stretching force is continued until the exact dimension is obtained whereupon the stretching force is interrupted by the photocell.
  • the film is passed over driving rolls 31 and a dancer roll 32 connected with a microswitch (not shown) and a magnetic coupling (not shown) for driving the rolls 31 and then to a device 33 corresponding essentially to that one shown in FIGURE 1.
  • the most important part of this device is a hollow cylinder 36 serving as a film brake, the brake effect thereof being controlled by the photocell 34.
  • the film runs past the photocell 34 via a deflection roll 35 into the packaging machine 37.
  • the photocell 34 responds to the metering marks on the film and prolongs the brake impulse, i.e. the period during which the hollow cylinder 36 is connected with the vacuum line, until the required stretching is obtained.
  • the action of the film brake of this invention is so smooth that tearing of films, even those with low elasticity, can not occur.
  • the control is effected in a simple manner in that the photocell 34 switches an electromagnetic three-way tap (not shown) by which the hollow cylinder 36 is connected either with the vacuum line or with the atmosphere.
  • a process for controlling a relatively gas impermeable, moving sheet which is supplied from a source having sufficient mass to be diflicult to immediately brake to a complete stop comprising the steps of:
  • Apparatus for controlling moving sheets compris- (a) at least one stationary, hollow, cylindrical, guide member having at least one channel in its surface parallel to its longitudinal axis and transverse to the direction of travel of said moving sheets, the cross section of said channel having a stepped cross section wherein the top of said channel is wider than the bottom;
  • the apparatus of claim 2 including two stationary cylindrical guide members and including means for applying a subatmospheric pressure simultaneously to the openings in the channels of each guide member.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Advancing Webs (AREA)
  • Registering, Tensioning, Guiding Webs, And Rollers Therefor (AREA)
US534703A 1965-04-01 1966-03-16 Vacuum control for moving sheets Expired - Lifetime US3396887A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DED0046943 1965-04-01

Publications (1)

Publication Number Publication Date
US3396887A true US3396887A (en) 1968-08-13

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Application Number Title Priority Date Filing Date
US534703A Expired - Lifetime US3396887A (en) 1965-04-01 1966-03-16 Vacuum control for moving sheets

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US (1) US3396887A (enrdf_load_stackoverflow)
DE (1) DE1499016B (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3685710A (en) * 1971-04-12 1972-08-22 Continental Can Co Method and apparatus for transporting a coated paper web
US5779184A (en) * 1995-03-17 1998-07-14 Voith Sulzer Papiermaschinen Gmbh Device and method for stabilizing a paper web at a time before the web is cut
WO2004074754A1 (en) * 2003-02-14 2004-09-02 3M Innovative Properties Company Web positioning device
US20080179304A1 (en) * 2007-01-26 2008-07-31 Electro Scientific Industries, Inc. Methods and systems for laser processing continuously moving sheet material

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3091794A (en) * 1961-02-21 1963-06-04 Ampex Tape cleaning apparatus
US3227348A (en) * 1964-02-17 1966-01-04 Rca Corp Magnetic tape system
US3231668A (en) * 1960-09-09 1966-01-25 Victor Company Of Japan Magnetic recording and reproduction stabilizing system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3231668A (en) * 1960-09-09 1966-01-25 Victor Company Of Japan Magnetic recording and reproduction stabilizing system
US3091794A (en) * 1961-02-21 1963-06-04 Ampex Tape cleaning apparatus
US3227348A (en) * 1964-02-17 1966-01-04 Rca Corp Magnetic tape system

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3685710A (en) * 1971-04-12 1972-08-22 Continental Can Co Method and apparatus for transporting a coated paper web
US5779184A (en) * 1995-03-17 1998-07-14 Voith Sulzer Papiermaschinen Gmbh Device and method for stabilizing a paper web at a time before the web is cut
WO2004074754A1 (en) * 2003-02-14 2004-09-02 3M Innovative Properties Company Web positioning device
US6996921B2 (en) 2003-02-14 2006-02-14 3M Innovative Properties Company Web positioning device
US7159334B2 (en) 2003-02-14 2007-01-09 3M Innovative Properties Company Web coating machine
US20080179304A1 (en) * 2007-01-26 2008-07-31 Electro Scientific Industries, Inc. Methods and systems for laser processing continuously moving sheet material
US9029731B2 (en) * 2007-01-26 2015-05-12 Electro Scientific Industries, Inc. Methods and systems for laser processing continuously moving sheet material
US10118252B2 (en) 2007-01-26 2018-11-06 Electro Scientific Industries, Inc. Methods and systems for laser processing continuously moving sheet material

Also Published As

Publication number Publication date
DE1499016B (enrdf_load_stackoverflow) 1970-02-12

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