METERING BAR
United States Patent 3785340
Deflection correction metering bar assembly for metering coating on a web. The assembly includes a rod holder having a recess extending along its top portion, a metering rod mounted in said recess, deflection correction bars for said rod holder, carrying jacking screws deflecting the rod holder in horizontal and vertical planes and holding the rod holder against sagging vertically or deflecting horizontally. A fluid passageway leads through the rod holder to accommodate the passage of temperature control fluid therethrough, to prevent coating from building up on the metering rod, and maintain an even coating on the web.
US Patent References:
/1312034.html
Jones - August 1919 - 1312034
Veneer machine knife clamp
Koss, Jr. - December 1932 - 1890582
Coating evening means for paper laminating machines
Charters - November 1940 - 2221441
Doctor blade for coating machines
Montgomery et al. - November 1954 - 2695004
Reverse bar coater
Hornbostel - April 1962 - 3029779
/1312034.html
Jones - August 1919 - 1312034
Veneer machine knife clamp
Koss, Jr. - December 1932 - 1890582
Coating evening means for paper laminating machines
Charters - November 1940 - 2221441
Doctor blade for coating machines
Montgomery et al. - November 1954 - 2695004
Reverse bar coater
Hornbostel - April 1962 - 3029779
Inventors:
Stafford, Larry O. (Beloit, WI)
Wentworth, William P. (Rockford, IL)
Melead, James J. (Roscoe, IL)
Wentworth, William P. (Rockford, IL)
Melead, James J. (Roscoe, IL)
Application Number:
05/278710
Publication Date:
01/15/1974
Filing Date:
08/08/1972
View Patent Images:
Export Citation:
Assignee:
Beloit Corporation (Beloit, WI)
Primary Class:
Other Classes:
118/123, 118/118
International Classes:
B05C11/02; B05C11/04; B05C11/04
Field of Search:
118/110,101,116-119,121-123,126 117/12M,12L,114R,64R,114A,64C,114B,114C 15/265.5
US Patent References:
Primary Examiner:
Kaplan, Morris
Attorney, Agent or Firm:
Benjamin, Sherman Et Al H.
Claims:
We claim as our invention
1. In a metering bar for metering coating on a web,
2. The metering bar of claim 1,
3. The metering bar of claim 2, wherein the metering rod is circular in cross section and retainers are provided at opposite ends of said rod for retaining said rod to said groove.
4. The metering bar of claim 2, wherein the metering rod is rectangular in cross section and a corner of the rectangle forms a support for the web.
5. The metering bar of claim 2,
6. The metering bar of claim 2, wherein the metering rod is a smooth, round glass rod.
7. The metering bar of claim 2, wherein the metering rod is a round metal rod tightly wound with wire.
8. The metering bar of claim 2,
9. The metering bar of claim 8,
10. The metering bar of claim 9, in which the conduit is spaced from the rod holder and the space between said conduit and rod holder is filled with a heat transfer cement, transferring the heat from said conduit to said rod holder and rod and accommodating deflection of said rod holder relative to said conduit.
11. The metering bar of claim 2, wherein the means for correcting deflection of said rod holder and rod in a vertical direction comprise jack pads connecting said deflection correction members together and jack screws threaded in said pads and operable to exert deflection correcting forces on said rod holder at equally spaced points therealong.
12. The metering bar of claim 11, wherein the jack screws exert a pushing action on said rod holder, and wherein pull screws are interposed between certain of said jack screws at equally spaced points therealong to exert a downwardly pulling action on said rod holder.
13. The metering bar of claim 2,
14. In a coater,
15. The coater of claim 14, wherein the jack screws exert a pushing action on said rod holder and other pads are disposed between said first-mentioned pads and have pull screws passing therethrough having threaded engagement with said rod holder and cooperating with said jack screws to correct deflection thereof.
16. The coater of claim 14,
17. The coater of claim 14,
18. The coater of claim 14, wherein power means are provided for rotatably driving said metering rod at a uniform rate of speed at the selection of the operator of the machine.
1. In a metering bar for metering coating on a web,
2. The metering bar of claim 1,
3. The metering bar of claim 2, wherein the metering rod is circular in cross section and retainers are provided at opposite ends of said rod for retaining said rod to said groove.
4. The metering bar of claim 2, wherein the metering rod is rectangular in cross section and a corner of the rectangle forms a support for the web.
5. The metering bar of claim 2,
6. The metering bar of claim 2, wherein the metering rod is a smooth, round glass rod.
7. The metering bar of claim 2, wherein the metering rod is a round metal rod tightly wound with wire.
8. The metering bar of claim 2,
9. The metering bar of claim 8,
10. The metering bar of claim 9, in which the conduit is spaced from the rod holder and the space between said conduit and rod holder is filled with a heat transfer cement, transferring the heat from said conduit to said rod holder and rod and accommodating deflection of said rod holder relative to said conduit.
11. The metering bar of claim 2, wherein the means for correcting deflection of said rod holder and rod in a vertical direction comprise jack pads connecting said deflection correction members together and jack screws threaded in said pads and operable to exert deflection correcting forces on said rod holder at equally spaced points therealong.
12. The metering bar of claim 11, wherein the jack screws exert a pushing action on said rod holder, and wherein pull screws are interposed between certain of said jack screws at equally spaced points therealong to exert a downwardly pulling action on said rod holder.
13. The metering bar of claim 2,
14. In a coater,
15. The coater of claim 14, wherein the jack screws exert a pushing action on said rod holder and other pads are disposed between said first-mentioned pads and have pull screws passing therethrough having threaded engagement with said rod holder and cooperating with said jack screws to correct deflection thereof.
16. The coater of claim 14,
17. The coater of claim 14,
18. The coater of claim 14, wherein power means are provided for rotatably driving said metering rod at a uniform rate of speed at the selection of the operator of the machine.
Description:
FIELD OF THE INVENTION
Metering bars for metering coatings on webs of paper making machine, or paper finishing machine.
BACKGROUND, SUMMARY AND ADVANTAGES OF INVENTION
Metering bars have been in common use for metering coating on a web as the freshly coated web passes thereover. The present-day coaters are becoming increasingly wider with the result that the bar tends to sag or deflect horizontally. This limits the width of the machine or where a wider machine is required, makes it advantageous to correct for deflection in either vertical or horizontal planes.
Such metering units have made some provision for heating or cooling the metering rod holder in accordance with the temperature of the coating material. These provisions, however, have not been satisfactory, due to leakage, many times caused by deflection of the bar.
In carrying out our present invention, we control the temperature of the metering bar holder and metering rod carried thereby by a fluid, gas or electric heat, and where the control is by a fluid which may be steam, liquid or gas, we provide a continuous manifold recessed in the metering bar holder with no joints in the manifold and spaced from the holder so as to be unaffected by deflection thereof. The space between the manifold and holder is then filled with a heat transfer cement retaining the manifold to the holder and transferring the heat of the fluid passing through the manifold to the rod holder and metering rod carried thereby. The heat transfer fluid is conducted to and from the manifold by fittings near the ends of the rod holder and unaffected by horizontal or vertical deflection of the holder.
We also mount the rod holder at its ends and control horizontal and vertical deflection of the rod by jack screws rigidly supported in a deflection correction frame and positioned to have jacking engagement with the bottom and sides of the rod holder, to correct deflection thereof in a vertical plane and to maintain the rod holder straight in a horizontal plane, or to deflect the rod holder horizontally under certain circumstances.
The advantages of the present invention, therefore, are that the coating rod holder may extend for the width of a web and maintain the rod clean by heating or cooling the rod holder and rod supported thereon.
A further advantage of the invention is the provision of a coater bar assembly in which the bar is maintained clean and differences in temperature of the coating are compensated for by means of a fluid or gas passed through a conduit or manifold recessed in the rod holder, and unbroken throughout its entire length, and held to the rod holder within the marginal limits thereof by a heat transfer cement.
Another advantage of the invention is the mounting of the rod holder at its ends and the correction of deflection of the rod holder and rod by the use of jack screws engaging the mounting means for the rod holder.
A still further advantage of the invention is the support of the rod holder carrying the metering rod at its ends and the arrangement of the support means therefor to correct for horizontal and vertical deflection of the rod, to maintain the plane of the web engaging surface of the rod in a predetermined straight line plane, but to accommodate horizontal deflection of the rod as required for certain coating conditions.
A principal object of the present invention, therefore, is to provide a metering bar for metering coating on a web in which a rod holder extending transversely of the web forms a support for the metering rod and is arranged to maintain the temperature of the coating to keep the coating in a fluid state and to crown the metering rod vertically as well as correct for horizontal deflection of the rod.
Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary view in side elevation of a metering bar assembly constructed in accordance with the principles of the present invention, with certain parts removed.
FIG. 2 is a cross sectional view taken substantially along line II--II of FIG. 1 and illustrating the rod holder and jack means for correcting horizontal and vertical deflection of the rod holder and metering rod carried thereby.
FIG. 3 is a sectional view taken substantially along line III--III of FIG. 1 illustrating the use of pull screws to aid in the correction of deflection of the rod holder.
FIG. 4 is a fragmentary sectional view of the rod holder, illustrating a different form of metering rod from that shown in FIGS. 2 and 3.
FIG. 5 is a fragmentary sectional view of the rod holder illustrating still another form of metering rod that may be used.
FIG. 6 is a fragmentary plan view of a form of metering rod wound by fine wire.
FIG. 7 is a fragmentary sectional view showing the metering rod of FIG. 6 carried by the rod holder.
FIG. 8 is a fragmentary partial sectional view in side elevation illustrating a form of detachable mounting of the rod to the rod holder at one end of the rod and illustrating a drive for rotating the rod where required.
FIG. 9 is a fragmentary view in side elevation illustrating the mounting of the opposite end of the rod from that shown in FIG. 8.
DESCRIPTION OF PREFERRED EMBODIMENT OF INVENTION
In FIGS. 1, 2 and 3 of the drawings, we have shown a metering bar assembly 10 extending beneath and transversely of the coated web 11, and carrying a metering rod 12 having metering engagement with the underside of the coated web. The metering bar assembly includes a rod holder 13 having converging upper sides terminating into an upwardly opening recess 15, generally conforming to and forming a support for the metering rod 12 as will hereinafter more clearly appear as this specification proceeds. The rod holder 13 is mounted at each end on a block 16 (FIG. 1) mounted on the top of and extending inwardly from a mounting block 17 secured to the main frame (not shown) of the coater, as by bolts 18, to support the metering bar holder to extend transversely of the web 11.
Mounted at their opposite ends on the mounting block 17 in spaced relation with respect to opposite sides of the rod holder 13 are deflection correcting plates 19, extending in parallel relation with respect to each other along, and downwardly of opposite parallel sides 20 of the rod holder, and forming reaction means for the deflection correcting means for the rod holder. The deflection correction plates may be mounted at their opposite ends on the insides of the mounting blocks 17, to extend therebetween, as by welding, or in any other suitable manner.
The deflection correction plates 19 are connected together intermediate their ends and at their lower end portions at intervals by pressure pads 21, which may be welded or otherwise secured thereto. The pressure pads 21 may be threaded vertically and have deflection correcting jack screws 23 threaded therein and abutting the underside of a plate 24, extending along the bottom of the rod holder 13, and closing a downwardly opening recess or passageway 25 extending therealong, for the length thereof. The closure plate 24 is adapted to be secured to the bottom of the rod holder 13 as by machine screws 26. For convenience of reference the combined deflection correcting plates 19 with the pressure pads 21 may be termed a channel member and it will be appreciated by those versed in the art that this may take various structural forms to function to apply forces to the sides and bottom of the rod holder 13.
The passageway 25 forms a passageway for a manifold or conduit 27 for a temperature compensating liquid or gas. The conduit 27 is shown as spaced from the wall of the passageway 25 and is unbroken over its entire length. The conduit 27 turns downwardly at its opposite ends, to form an inlet 29 for a liquid or gas at one end thereof and an outlet 30 at the opposite end thereof, to accommodate the continuous flow of liquid or gas through said conduit. The liquid or gas may either be heated or cooled and is usually of a different temperature than ambient temperature.
The conduit 27 is retained in the passageway 25 as by a suitable form of heat transfer cement 31, transferring the heat flowing through said conduit to the rod holder 13 and rod 12. The heat transfer cement may be of a type which will not only hold the conduit in place, but also accommodate deflection of the rod holder relative to said conduit without rupturing the cement, when correcting the deflection of the rod holder and rod.
While we have herein shown a fluid conduit 27 for heating or cooling the rod where required, it should be understood that an electric heating coil may be substituted for or extend along the conduit where it may be desirable to heat the rod holder and rod by electric heat.
Referring now in particular to the means correcting horizontal deflection of the rod holder 13 and rod 12 where required, a plurality of set screws 32 are threaded in the deflection correction plates 19 at equally spaced intervals along said plates and have engagement with the opposite parallel walls 20 of the rod holder. Lock nuts 33 are provided to lock said set screws in position when the rod holder is in its aligned position, or in a horizontally deflected position, where it may be desired to bow the metering rod in a horizontal plane.
The means for correcting sagging of the rod holder is shown as comprising a plurality of equally spaced jack screws 36, threaded in the pads 21 and having jacking engagement with the rod holder 13 through the closure plate 24. Lock nuts 37 are provided to lock the jack screws in position. The jack screws 36 may thus deflect the rod holder to control the deflection or crown of the rod holder and rod 12 supported thereon, and retain the rod holder in position to hold the metering rod true or to place a crown on the metering rod, where this may be desirable for certain coating conditions. The screws while shown as single screws may be differential screws of a conventional form and in many cases are used in place of the pull screws.
In some cases, it may be desired to use pull screws to properly deflect the rod holder, although the pull screws need not necessarily be used. Where it is desired to use pull screws, pull screws 39 freely pass through the pads 21 between the jack screws and are freely rotatable with respect thereto. The free ends of said pull screws are shown as having threaded engagement with nuts 40, welded or otherwise secured to the bottom of the retainer plate 24 and depending therefrom. Nuts 41 are provided for placing the pull screws under tension to exert a pulling action on the rod holder and metering rod and straighten or deflect the rod holder, either by themselves, or in cooperation with the jacking screws.
Where the pull screws are not used, the nuts 41 are loosened or moved away from the pads 21 or the pull screws are removed, to accommodate free deflection of the rod holder by the jack screws 36.
Where differential screws may be used, the screws will replace the screws 36 and 39 and may exert a pushing or pulling action on the rod holder to deflect the rod holder to the required extent.
The metering rod 12 is shown in FIGS. 2 and 3 as being a round rod fitting within the upwardly opening recess 15 in the rod holder 13 and extending beyond opposite ends of said rod holder. The metering rod 12 may be mounted at one end in a rod retainer 42 (FIG. 1) mounted on the frame of the machine in a suitable manner, which is not herein shown or described since it forms no part of the present invention. The opposite end of the metering rod may be mounted in a similar rod retainer (not shown).
Where round rods are used, it may be desirable to continuously rotate the rod. In such cases, the opposite end of the metering rod 12 from the retainer 42 extends within a socket 43 carried in a guide 44 for the end of said metering rod. A shaft 46 forms an extension of the socket 43 and is connected at its end to a universal joint 47 carried in a frame member 49 mounted on the frame of the machine. A motor 50, which is shown as being a fluid pressure operated motor, but which may be an electric motor or any other form of mechanical drive means, is mounted on a bracket member 51 and has connection with the universal joint 47 through a motor shaft 48 for rotatably driving said metering rod where desired or required. It should be understood, however, that the metering rod need not necessarily be rotatably driven and in many cases, is held from rotation. A coil spring 52 is interposed between the rod holder and guide 44 to accommodate flexing of the rod holder and rod when correcting deflection thereof and the fluid pressure operated motor is connected to rotatably drive the rod.
In FIG. 4 of the drawings, we have shown a metering rod 56 square in cross section, and fitting in an upwardly opening right angled recess 57 in a rod holder 13a. The right angled recess is positioned so that the metering rod 56 will be supported in angular relation with respect to the horizontal, with its apex metering coating from the underside of the web 11.
In FIG. 5 of the drawings, a rod holder 13b has a recess 58 like the recess 57 of the rod holder 13a in FIG. 4, for receiving a triangular metering rod 59 having a base 60 extending horizontally, and along which the web 11 passes, to meter coating therefrom.
One type of rod that is used for applications where most of the coating is to be taken off and the web is left with a slick or shiny surface is a glass rod, which has a very smooth surface. Another type of rod that is used is a metal rod made from stainless steel. The surface of such a rod, however, is not quite as slick or shiny as a glass rod.
In FIG. 7 of the drawings, a rod holder 13c has an upwardly opening semicircular recess 61 therein, forming a mounting for a metering rod 62 wound with fine wire 63. The wire 63 may be tightly coiled around said metering rod so one coil is touching the the next. The metering rod is preferably made from metal, such as stainless steel.
It may be seen from the foregoing that we have provided a new and improved form of metering bar assembly for metering coating on a web, which may be heated or cooled to compensate for either higher or lower temperature requirements of the coating of the web, to avoid lumps of coating on the web which may be caused by the building up of coating on the metering rod, and to maintain the metering rod clean to accomplish the function for which it is intended.
It may further be seen that the rod holder and metering rod may be adjusted to correct sagging or deflection of the rod holder and rod and may also be deflected horizontally to provide a true rod, or to put a predetermined horizontal deflection in the rod where desired, and that the structure just described accommodates the use of a far wider coater than has previously been practical and to run at higher speeds with varying temperatures and particularly such temperatures as will keep coating from collecting on the web before it hardens.
Metering bars for metering coatings on webs of paper making machine, or paper finishing machine.
BACKGROUND, SUMMARY AND ADVANTAGES OF INVENTION
Metering bars have been in common use for metering coating on a web as the freshly coated web passes thereover. The present-day coaters are becoming increasingly wider with the result that the bar tends to sag or deflect horizontally. This limits the width of the machine or where a wider machine is required, makes it advantageous to correct for deflection in either vertical or horizontal planes.
Such metering units have made some provision for heating or cooling the metering rod holder in accordance with the temperature of the coating material. These provisions, however, have not been satisfactory, due to leakage, many times caused by deflection of the bar.
In carrying out our present invention, we control the temperature of the metering bar holder and metering rod carried thereby by a fluid, gas or electric heat, and where the control is by a fluid which may be steam, liquid or gas, we provide a continuous manifold recessed in the metering bar holder with no joints in the manifold and spaced from the holder so as to be unaffected by deflection thereof. The space between the manifold and holder is then filled with a heat transfer cement retaining the manifold to the holder and transferring the heat of the fluid passing through the manifold to the rod holder and metering rod carried thereby. The heat transfer fluid is conducted to and from the manifold by fittings near the ends of the rod holder and unaffected by horizontal or vertical deflection of the holder.
We also mount the rod holder at its ends and control horizontal and vertical deflection of the rod by jack screws rigidly supported in a deflection correction frame and positioned to have jacking engagement with the bottom and sides of the rod holder, to correct deflection thereof in a vertical plane and to maintain the rod holder straight in a horizontal plane, or to deflect the rod holder horizontally under certain circumstances.
The advantages of the present invention, therefore, are that the coating rod holder may extend for the width of a web and maintain the rod clean by heating or cooling the rod holder and rod supported thereon.
A further advantage of the invention is the provision of a coater bar assembly in which the bar is maintained clean and differences in temperature of the coating are compensated for by means of a fluid or gas passed through a conduit or manifold recessed in the rod holder, and unbroken throughout its entire length, and held to the rod holder within the marginal limits thereof by a heat transfer cement.
Another advantage of the invention is the mounting of the rod holder at its ends and the correction of deflection of the rod holder and rod by the use of jack screws engaging the mounting means for the rod holder.
A still further advantage of the invention is the support of the rod holder carrying the metering rod at its ends and the arrangement of the support means therefor to correct for horizontal and vertical deflection of the rod, to maintain the plane of the web engaging surface of the rod in a predetermined straight line plane, but to accommodate horizontal deflection of the rod as required for certain coating conditions.
A principal object of the present invention, therefore, is to provide a metering bar for metering coating on a web in which a rod holder extending transversely of the web forms a support for the metering rod and is arranged to maintain the temperature of the coating to keep the coating in a fluid state and to crown the metering rod vertically as well as correct for horizontal deflection of the rod.
Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary view in side elevation of a metering bar assembly constructed in accordance with the principles of the present invention, with certain parts removed.
FIG. 2 is a cross sectional view taken substantially along line II--II of FIG. 1 and illustrating the rod holder and jack means for correcting horizontal and vertical deflection of the rod holder and metering rod carried thereby.
FIG. 3 is a sectional view taken substantially along line III--III of FIG. 1 illustrating the use of pull screws to aid in the correction of deflection of the rod holder.
FIG. 4 is a fragmentary sectional view of the rod holder, illustrating a different form of metering rod from that shown in FIGS. 2 and 3.
FIG. 5 is a fragmentary sectional view of the rod holder illustrating still another form of metering rod that may be used.
FIG. 6 is a fragmentary plan view of a form of metering rod wound by fine wire.
FIG. 7 is a fragmentary sectional view showing the metering rod of FIG. 6 carried by the rod holder.
FIG. 8 is a fragmentary partial sectional view in side elevation illustrating a form of detachable mounting of the rod to the rod holder at one end of the rod and illustrating a drive for rotating the rod where required.
FIG. 9 is a fragmentary view in side elevation illustrating the mounting of the opposite end of the rod from that shown in FIG. 8.
DESCRIPTION OF PREFERRED EMBODIMENT OF INVENTION
In FIGS. 1, 2 and 3 of the drawings, we have shown a metering bar assembly 10 extending beneath and transversely of the coated web 11, and carrying a metering rod 12 having metering engagement with the underside of the coated web. The metering bar assembly includes a rod holder 13 having converging upper sides terminating into an upwardly opening recess 15, generally conforming to and forming a support for the metering rod 12 as will hereinafter more clearly appear as this specification proceeds. The rod holder 13 is mounted at each end on a block 16 (FIG. 1) mounted on the top of and extending inwardly from a mounting block 17 secured to the main frame (not shown) of the coater, as by bolts 18, to support the metering bar holder to extend transversely of the web 11.
Mounted at their opposite ends on the mounting block 17 in spaced relation with respect to opposite sides of the rod holder 13 are deflection correcting plates 19, extending in parallel relation with respect to each other along, and downwardly of opposite parallel sides 20 of the rod holder, and forming reaction means for the deflection correcting means for the rod holder. The deflection correction plates may be mounted at their opposite ends on the insides of the mounting blocks 17, to extend therebetween, as by welding, or in any other suitable manner.
The deflection correction plates 19 are connected together intermediate their ends and at their lower end portions at intervals by pressure pads 21, which may be welded or otherwise secured thereto. The pressure pads 21 may be threaded vertically and have deflection correcting jack screws 23 threaded therein and abutting the underside of a plate 24, extending along the bottom of the rod holder 13, and closing a downwardly opening recess or passageway 25 extending therealong, for the length thereof. The closure plate 24 is adapted to be secured to the bottom of the rod holder 13 as by machine screws 26. For convenience of reference the combined deflection correcting plates 19 with the pressure pads 21 may be termed a channel member and it will be appreciated by those versed in the art that this may take various structural forms to function to apply forces to the sides and bottom of the rod holder 13.
The passageway 25 forms a passageway for a manifold or conduit 27 for a temperature compensating liquid or gas. The conduit 27 is shown as spaced from the wall of the passageway 25 and is unbroken over its entire length. The conduit 27 turns downwardly at its opposite ends, to form an inlet 29 for a liquid or gas at one end thereof and an outlet 30 at the opposite end thereof, to accommodate the continuous flow of liquid or gas through said conduit. The liquid or gas may either be heated or cooled and is usually of a different temperature than ambient temperature.
The conduit 27 is retained in the passageway 25 as by a suitable form of heat transfer cement 31, transferring the heat flowing through said conduit to the rod holder 13 and rod 12. The heat transfer cement may be of a type which will not only hold the conduit in place, but also accommodate deflection of the rod holder relative to said conduit without rupturing the cement, when correcting the deflection of the rod holder and rod.
While we have herein shown a fluid conduit 27 for heating or cooling the rod where required, it should be understood that an electric heating coil may be substituted for or extend along the conduit where it may be desirable to heat the rod holder and rod by electric heat.
Referring now in particular to the means correcting horizontal deflection of the rod holder 13 and rod 12 where required, a plurality of set screws 32 are threaded in the deflection correction plates 19 at equally spaced intervals along said plates and have engagement with the opposite parallel walls 20 of the rod holder. Lock nuts 33 are provided to lock said set screws in position when the rod holder is in its aligned position, or in a horizontally deflected position, where it may be desired to bow the metering rod in a horizontal plane.
The means for correcting sagging of the rod holder is shown as comprising a plurality of equally spaced jack screws 36, threaded in the pads 21 and having jacking engagement with the rod holder 13 through the closure plate 24. Lock nuts 37 are provided to lock the jack screws in position. The jack screws 36 may thus deflect the rod holder to control the deflection or crown of the rod holder and rod 12 supported thereon, and retain the rod holder in position to hold the metering rod true or to place a crown on the metering rod, where this may be desirable for certain coating conditions. The screws while shown as single screws may be differential screws of a conventional form and in many cases are used in place of the pull screws.
In some cases, it may be desired to use pull screws to properly deflect the rod holder, although the pull screws need not necessarily be used. Where it is desired to use pull screws, pull screws 39 freely pass through the pads 21 between the jack screws and are freely rotatable with respect thereto. The free ends of said pull screws are shown as having threaded engagement with nuts 40, welded or otherwise secured to the bottom of the retainer plate 24 and depending therefrom. Nuts 41 are provided for placing the pull screws under tension to exert a pulling action on the rod holder and metering rod and straighten or deflect the rod holder, either by themselves, or in cooperation with the jacking screws.
Where the pull screws are not used, the nuts 41 are loosened or moved away from the pads 21 or the pull screws are removed, to accommodate free deflection of the rod holder by the jack screws 36.
Where differential screws may be used, the screws will replace the screws 36 and 39 and may exert a pushing or pulling action on the rod holder to deflect the rod holder to the required extent.
The metering rod 12 is shown in FIGS. 2 and 3 as being a round rod fitting within the upwardly opening recess 15 in the rod holder 13 and extending beyond opposite ends of said rod holder. The metering rod 12 may be mounted at one end in a rod retainer 42 (FIG. 1) mounted on the frame of the machine in a suitable manner, which is not herein shown or described since it forms no part of the present invention. The opposite end of the metering rod may be mounted in a similar rod retainer (not shown).
Where round rods are used, it may be desirable to continuously rotate the rod. In such cases, the opposite end of the metering rod 12 from the retainer 42 extends within a socket 43 carried in a guide 44 for the end of said metering rod. A shaft 46 forms an extension of the socket 43 and is connected at its end to a universal joint 47 carried in a frame member 49 mounted on the frame of the machine. A motor 50, which is shown as being a fluid pressure operated motor, but which may be an electric motor or any other form of mechanical drive means, is mounted on a bracket member 51 and has connection with the universal joint 47 through a motor shaft 48 for rotatably driving said metering rod where desired or required. It should be understood, however, that the metering rod need not necessarily be rotatably driven and in many cases, is held from rotation. A coil spring 52 is interposed between the rod holder and guide 44 to accommodate flexing of the rod holder and rod when correcting deflection thereof and the fluid pressure operated motor is connected to rotatably drive the rod.
In FIG. 4 of the drawings, we have shown a metering rod 56 square in cross section, and fitting in an upwardly opening right angled recess 57 in a rod holder 13a. The right angled recess is positioned so that the metering rod 56 will be supported in angular relation with respect to the horizontal, with its apex metering coating from the underside of the web 11.
In FIG. 5 of the drawings, a rod holder 13b has a recess 58 like the recess 57 of the rod holder 13a in FIG. 4, for receiving a triangular metering rod 59 having a base 60 extending horizontally, and along which the web 11 passes, to meter coating therefrom.
One type of rod that is used for applications where most of the coating is to be taken off and the web is left with a slick or shiny surface is a glass rod, which has a very smooth surface. Another type of rod that is used is a metal rod made from stainless steel. The surface of such a rod, however, is not quite as slick or shiny as a glass rod.
In FIG. 7 of the drawings, a rod holder 13c has an upwardly opening semicircular recess 61 therein, forming a mounting for a metering rod 62 wound with fine wire 63. The wire 63 may be tightly coiled around said metering rod so one coil is touching the the next. The metering rod is preferably made from metal, such as stainless steel.
It may be seen from the foregoing that we have provided a new and improved form of metering bar assembly for metering coating on a web, which may be heated or cooled to compensate for either higher or lower temperature requirements of the coating of the web, to avoid lumps of coating on the web which may be caused by the building up of coating on the metering rod, and to maintain the metering rod clean to accomplish the function for which it is intended.
It may further be seen that the rod holder and metering rod may be adjusted to correct sagging or deflection of the rod holder and rod and may also be deflected horizontally to provide a true rod, or to put a predetermined horizontal deflection in the rod where desired, and that the structure just described accommodates the use of a far wider coater than has previously been practical and to run at higher speeds with varying temperatures and particularly such temperatures as will keep coating from collecting on the web before it hardens.