US 3735733 A
An applicator assembly for applying a liquid substance to at least one face of sheet material moving along a predetermined path comprising a housing defining a reservoir for the liquid substance, means for maintaining a predetermined level of the liquid substance in the reservoir, a roll member having at least one circumferentially extending pad mounted on its outer surface, means for rotatably mounting the roll member in said housing comprising vertical trackways in opposed end walls of said housing which in the operative position limit lateral movement of said roll assembly, and a doctor blade made of resilient material mounted along one edge of the housing having a plurality of longitudinally spaced openings therein adapted to engage and wipe said pads whereby a uniform predetermined quantity of liquid substance is applied to the sheet material irrespective of rotational speed of the roll member.
Claims available in
Description (OCR text may contain errors)
United States Patent 091 Henc May 29, 1973 APPLICATOR FOR PAPER HANDLING 2,300,078 10 1942 Von l-Iofe ..118/262 x APPARATUS FOREIGN PATENTS OR APPLICATIONS  Inventor: Edward V. Henc, Promisedale Farm, Boot Road, 2, Malvem, 392,601 5/1933 Great Britain ..118 244 Pa. 3 Primary Examiner-John P. McIntosh  Filed 1971 Attorney-Howson & I-Iowson  Appl. No.: 170,068
,  ABSTRACT Related U.S. Application Data An applicator assembly for applymg a liqu1d substance [6-3] Commuatw" of 31283 16, 1970, aban to at least one face of sheet material moving along a doned' predetermined path comprising a housing defining a reservoir for the liquid substance, means for maintainfi "118/ 33 43 1 4 ing a predetermined level of the liquid substance in 1 c l c I the reservoir, a roll member having at least one cir-  Field of Search ...,...1 18/221, 258, 261,
. cumferent1ally extendmg pad mounted on 1ts outer surface, means for rotatably mounting the roll member in said housing comprising vertical trackways  References Cited in opposed end walls of said housing which in the UNITED STATES PATENTS operative position limit lateral movement of said roll 3 025 align S 8/235 X assembly, and a doctor blade made of resilient materi- 638,757 12/1899 Pratt ..118 244 X molmted along. edge of the havmg.a 2 269 50 H1942 Flynn 8/26, X plurality of longitudinally spaced openings therein 4551954 7/1891 Smith ...118 415 and 1 Said P whereby 3,640,203 2/1972 Raab et 1 13 X umform predetermmed quantity of l1qu1d substance is 504,224 8/1893 Lappe et al... 118/224 X applied to the sheet material irrespective of rotational 989,685 8/1911 Zittle et al.... ..118/258 speed of the roll member. 1,119,820 12/1914 Gillespie i ..118/249 2,198,066 4/1940 Staude ..118/261 X 10 Claims, 12 Drawing Figures PATENI M91973 SHEET 1 0F 3 FIG. I.
INVENTOR EDWAR D V. HENC ATTYS APPLICATOR FOR PAPER HANDLING APPARATUS This is a continuation of my prior application entitled Applicator for Paper Handling Apparatus, filed Jan. 16, 1970, under Ser. No. 3,283, now abandoned.
The present invention relates to apparatus for handling paper products and the like and more specifically is directed to improved adhesive applicator for use in apparatus of this type.
The present invention is specially suited for use in apparatus for making corrugated board or the like.
In some instances these apparatus include an applicator for applying a fluid substance such as a contact adhesive to one face of the sheet material during passage of the sheet material through the apparatus. The applicator is designed to apply the contact adhesive in strip form, the strips serving as anti-skid means when the corrugated board is assembled in the form of a box. These anti-skid strips are for the purpose of preventing relative movement of the boxes when they are stacked in large quantities, one on top of the other, during handling and shipment. Generally these applicators consist of a plurality of brushes which are spaced apart and which communicate with a reservoir for the fluid substance such as the contact adhesive. The sheetmaterial is pressed into contact with the brushes by means of a hold-down roll and the substance flows through the brushes to the face of the sheet material by capillary action.
These prior applicators have certain disadvantages and drawbacks. For example, since the fluid substance is gravity fed if the applicator is disposed above the path of movement of the sheet material or by capillary action if it is disposed below the path of the sheet mate rial, it has been found that there is uneventransfer of the fluid substance to the sheet even if the sheet is moving at a predetermined linear speed. Of course, in cases where the linear speed is varied, the anti-skid strip varies in density. This, of course, is undesirable.
Another disadvantage of these applicator substances is that in most instances the contact adhesive is quick setting, presenting the problem of fouling parts of the apparatus when it is shut down for any length of time. It has also been observed that the brushes have a limited life and require comparatively frequent replacement.
The present invention provides a solution to these problems and basically comprises a reservoir for a liquid adhesive material and means for continuously pumping the fluid adhesive to the reservoir, the level in the reservoir being maintained at a predetermined level by a gravity outlet at the opposite end from the feed end. In the present instance, a hollow cylinder which mounts a plurality of axially spaced circumferentially extending porous pads is mounted in the reservoir in such a manner that it floats and seeks its own level. To this end the cylinder had a stub shaft at each end which engages in a slot provided by vertically extending guide members at opposite ends of the reservoir. In the present instance, the guide members extend to a point above the base of the reservoir slightly greater than the radius of the cylinder and have outwardly directed lower edge portions whereby, when the applicator is not in use, the roll is simply submerged and displaced to one side whereby the stub shafts engage the lower edges of the guide brackets to maintain it in a submerged position. By this arrangement, there is no danger of parts of the applicator being damaged by reason of the adhesive drawing on any important parts thereof during shutdown of the apparatus.
Accordingly, the present invention obviates some of the problems of prior applicator arrangements. For example, by reason of the frictionless floating mounting of the cylinder, there is no need for a hold-down roll and the pressure on the board as it is being fed over the cylinder is self-adjusting. By this arrangement, there is no damage to the flute of the board. Moreover, the arrangement insures even application of adhesive at all running speeds. Furthermore, the applicator is easy and quick to set up for operation and may be readily stored simply by submerging it. Additionally, there is no problem of maintenance or replacement of parts for example, bearings, which may be damaged by reason of the adhesive material drying on parts thereof.
These and other objects of the present invention and the various features and details of the operation and construction thereof are hereinafter more fully set forth with reference to the accompanying drawings, wherein;
FIG. 1 is a plan view of an adhesive applicator constructed in accordance with the present invention and showing a section of sheet material, for example corrugated board;
FIG. 2 is an enlarged sectional view taken on lines 2-2.of FIG. 1;
FIG. 3 is a sectional view similar to FIG. 2 except that the cylinder is in its upper limit position;
FIG. 4 is an enlarged sectional view taken on lines 4-4 of FIG. 11;
FIG. 5 is a sectional view taken on lines 5-5 of FIG. 4 showing the cylinder in a stored position;
FIG. 6 is a fragmentary perspective view of the flexible doctor blade;
FIG. 7 is an enlarged fragmentary sectional view of the area of FIG. 2 indicated in broken line;
FIG. 8 is a fragmentary view showing a spring biasing means for maintaining the transfer roll assembly in an elevated position;
FIG. 9 is a fragmentary plan view of a modified form of applicator assembly;
FIG. 10 is a transverse section thereof taken on the line 10-10 of FIG. 9',
FIG. 11 is a fragmentary vertical section as viewed from the line 11-11 of FIG. 9; and
FIG. 12 is an exploded perspective of the several components for mounting the rolls as they would appear as viewed from the wall side of the housing assembly.
Referring now to the drawings and particularly to FIGS. 1 and 2 thereof, there is illustrated an applicator generally designated by the numeral 10 which is constructed in accordance with the present invention and, as illustrated, is adapted for applying a fluid substance such as a contact adhesive to provide a plurality of antiskid strips S on at least one face of sheet material such as corrugated board B or the like.
The applicator comprises a trough-like housing 14 forming a reservoir for the fluid substance having parallel opposed side walls 16, abottom wall 18 and opposed end walls 20 and 22. The applicator further includes a transfer roll assembly 23 having means thereon for Uansferring the fluid substance from the reservoir to the sheet material in strip form. The housing also has brackets 24 and 26 of inverted L-shaped cross section mounted adjacent the upper edge of the opposing side walls, one of the brackets 24 mounting a doctor blade 30 which in the present instance is made of a resilient material and is adapted to engage and wipe the roll in the manner illustrated so that a uniform predetermined quantity of the adhesive is applied to the sheet material upon rotation of the transfer roll assemblies. One of the end walls mounts a fitting 27 for a line to be connected to a suitable supply source for pumping the adhesive material to the reservoir, and the opposite end of the housing is provided with a discharge opening 29 and a fitting 31 to provide a gravity outlet to control the level of the fluid in the reservoir.
In accordance with the present invention, a substantially frictionless rotary transfer roll assembly 23 is provided for transferring the fluid substance from the reservoir to the sheet material. This means, as best illustrated in FIGS. 2 and 3, comprises a hollow cylindrical roll member 40 having, in the present instance, a plurality of circumferentially extending axially spaced pads 42 preferably made of an absorbent material such as a closed cell neoprene which is nitrogen filled. The hollow tubular roll member 40 mounts stub shafts 44 and 46 at opposite axial ends which engage in vertical trackways 48 defined by spaced apart post members 58 and 60 mounted on the inner face of the end walls and 22 of the housing. This arrangement prevents lateral movement of the hollow roll member 40 in the housing. As illustrated, a block 62 is mounted at the upper terminal end between the strips to set an upper limit position for the hollow cylinder.
The post members 58 and 60 are spaced a predetermined height above the bottom wall of the housing so that the hollow roll member 40 may be submerged and displaced to one side to theposition shown in FIG. 5 when the applicator is not in use. Of course, submerging the roll member 40 precludes the possibility of adhesive caking on exposed parts of the cylinder and pads 42 when the applicator is out of use. Note also that the width of the reservoir is such that the stub shafts 44 and 46 engage the lower terminal edge of one of the pairs of posts when it is displaced to one side and the lower terminal edges 58a and 60a of the posts are bevelled upwardly to maintain the cylinder in a submerged position.
In operation of the applicator constructed in accordance with the present invention, the unit is simply mounted in a position relative to the feed rolls (not shown) which advance the sheet material past the applicator so that the board is in a position to depress the cylinder from its upper limit position (FIG. 3) to the position illustrated in FIG. 2. In the present instance, the applicator is described in connection with a machine for making corrugated board comprising inner and outer liner sheets L and a fluted medium M between the linear sheets. In this manner there is a predetermined uniform pressure on the board at all times which is a safe pressure which will not crush the flutes. It is noted that this pressure relationship is maintained by reason of the fact that the level of the fluid in the reservoir is maintained constant by the gravity outlet arrangement. Of course, by reason of the linear movement of the sheet material over the roll, the roll is rotated and the adhesive material is carried on the pads past the doctor roll, excess adhesive material falling back into the reservoir. The doctor blade has a bevelled edge 31 and is provided with a series of spaced openings 33 so that any adhesive dripping back along the top edge does back into the reservoir. This arrangement insures transfer of a uniform layer of the adhesive to the sheet material regardless of the linear speed thereof.
The bottom wall 18 of the housing 14 is provided with a drain line having a suitable valve (not shown) for purging the reservoir when desired.
It is readily apparent that the present invention provides an improved applicator for use in providing antiskid strips on sheet material or the like which overcomes the disadvantages and drawbacks of prior applicators used for this purpose. When the applicator of the present invention, a uniform strip of the fluid substance is applied to the sheet material irrespective of the linear feed speed. Moreover, by reason of the frictionless floating mounting arrangement of the cylinder, the need for a hold-down roll is obviated and hence there is no danger of damage to the flutes in the sheet material in the case of corrugated board. Additionally, since no bearings are necessary and the applicator roll may be submerged readily for storage, there is no problem of caking of the adhesive material on parts of the applicator when it is not in operation.
There is illustrated in FIG. 8 a modified arrangement for mounting the transfer roll assembly 23. The mounting arrangement includes, as in the previously described embodirnent, a pair of post members 158 and 160 which are spaced apart to define a trackway 148 within which the stub shafts engage, and a block 162 mounted at the upper end of the trackway. In the present instance, the confronting side faces of the post members are provided with dovetail slots 74 and 76 to receive a lower block member 80 which is biased by means of a spring 82 to maintain the transfer roll in an elevated position. The spring is carried by a pivotally mounted support member 84 and is held in the position illustrated by means of a leaf spring 86. As shown, the leaf spring has an angularly offset leg 88 which is engaged by the stub shafts to maintain the transfer roll in a submerged position when desired. The above described arrangement is useful in applications where it is difficult to maintain a predetermined fluid level in the reservoir. In other words, the biasing arrangement insures engagement of the pads of the transfer roll with the doctor blade thereby to insure even or uniform transfer of the fluid material.
There is illustrated in FIGS. 9-12 another embodiment of applicator assembly generally designated by the numeral which is constructed in accordance with the present invention and is adapted for applying a fluid substance such as a contact adhesive to provide a plurality of anti-skid strips S on at least one face of sheet material such as corrugated board B or the like. Even though the applicator is illustrated in connection with applying anti-skid strips, it is readily apparent that it may also be used for applying a continuous coating of a liquid substance to one face of sheet material.
The applicator comprises a trough-like housing 114 forming a reservoir for the fluid substance having parallel opposed side walls 116, 116, a bottom wall 118, and opposed end walls 120, 120. One of the end walls mounts a fitting 127 for a line to be connected to a suitable supply source for pumping the liquid material to the reservoir, and the bottom of the housing is provided with a discharge opening 129 and a fitting 131 to provide a gravity outlet to maintain the level of the fluid in the reservoir at a predetermined height continuously.
In the present instance, the applicator assembly includes a rotatably mounted transfer roll 140 having approximately one-half thereof submerged in the liquid in the bottom of the reservoir and a rotatably mounted applicator roller 141 having, in the present instance, a plurality of circumferentially extending axially spaced pads 142 preferably made of a non-absorbent material, such as a closed cell neoprene, which is nitrogen filled. As illustrated, the pads are in contact with the transfer roll, and upon movement of the sheet material in the direction indicated, the applicator roll is rotated which in turn rotates the transfer roll. Rotation of the rolls in this manner effects transfer of a predetermined uniform quantity of the liquid substance to the pads 142 and thence to the face of the sheet material in contact with the applicator roll. lfdesired, a hold-down roll M3 may be provided which maintains the sheet material in contact with the applicator pads of the applicator roll in the manner illustrated. The assembly further includes a doctor blade 146 having a plurality of openings 148 therein which is mounted along the side of the housing and engages the pads to effect the uniform predetermined quantity of the liquid substance applied to the sheet material.
in the present instance, the applicator roll and transfer roll are provided with stub shafts 141a and 140a respectively. As illustrated, the stub shafts engage in a trackway 151] in the end walls which are defined by a pair of spaced apart block members 152 and 154 respectively. These block members are cut with a diagonal recess 156 and 158 adjacent their lower terminal ends to mount a pair of trapezoidally-shaped wedges 160 and 162. The wedges each are provided with confronting recesses mounting a spring 1 which urges the upper block member in engagement with the stub shaft of the transfer roll, thereby to' maintain a predetermined uniform pressure-applying relation between the transfer and applicator rolls. Note that the trackway 1511 is closed at its upper terminal end by a stop member 1711 mounted on the roll release plate 172 at opposite ends of the housing. The roll release plate 172 has a pair of bayonet slots facing in opposite directions at opposite ends which, in the mounted position, retain the rolls in the assembled relation by means of screws and wing nuts. When it is desired to release the rolls, the wing nuts simply have to be loosened slightly, and the release plate rotated and lifted out of the way to open the trackway 150 and permit the rolls to be easily removed, for example when the applicator is not in use.
This applicator has various functional advantages similar to the previously described application. For example, it is easy to set up and dismantle for cleaning purposes. it provides frictionless rotary movement without any precision bearings which may become fouled or damaged. it has an automatic self-adjusting applicator pressure and applies an even coating at all running speeds.
ll. An applicator assembly for applying a liquid substance to at least one face of sheet material moving along a predetermined pathcomprising a housing defining a reservoir for the liquid substance, means for maintaining a predetermined level of the liquid substance in the reservoir, a roll member having at least one circumferentially extending pad mounted on its outer surface, means for rotatably mounting the roll member in said housing comprising vertical trackways in opposed end walls of said housing which in the operative position limit lateral movement of said roll assembly, means normally urging said roll member in a direction toward said one face of said sheet material to maintain a predetermined pressure applying relation therewith, and a doctor blade made of resilient material mounted along one edge of the housing having a plurality of longitudinally spaced openings therein adapted to engage and wipe said pads whereby a uniform predetermined quantity of liquid substance is applied to the sheet material irrespective of rotational speed of the roll member.
2. An applicator assembly as claimed in claim 1 wherein said roll member is completely enclosed so that it is adapted to float in said liquid substance and providing said means for urging said roll member in said direction.
3. An applicator assembly as claimed in claim 1 wherein said pad is made of a closed cell neoprene which is nitrogen filled.
4. An applicator assembly as claimed in claim 1 wherein each of said trackways at opposite ends of said housing is defined by a pair of spaced apart post members mounted on the inner end wall, said trackway at the upper end of said housing being closed by a block member to limit the upward movement of said roll assembly in the trackways.
5. An applicator assembly as claimed in claim 4 wherein said roll member is hollow and mounts stub shafts at opposite axial ends and wherein the lower terminal edge of said post members are outwardly tapered, the tapered edge of each post being located a predetermined distance from the bottom and side wall of the housing so as to engage the stub shaft when the hollow roll member is submerged at the lower portion of said housing for storage purposes.
6. An applicator assembly as claimed in claim 4 including means for urging said rollmember in a direction toward said block member.
7. An applicator assembly as claimed in claim 1 including means for continuously supplying the liquid substance to said reservoir and including a gravity discharge port for automatically maintaining a predetermined level of said liquid substance in said reservoir.
8. An applicator assembly as claimed in claim 1 including a second transfer roll member rotatably mounted in said housing at least partially submerged in said liquid substance, and biasing means urging said transfer roll member toward said applicator roll to effect transfer of liquid substance from said transfer roll to said applicator pad and providing said means for urging said roll member in said direction.
9. An applicator assembly as claimed in claim 8 including a release plate detachably secured to said housing to maintain the roll members in said trackway.
10. An applicator assembly as claimed in claim 9 wherein said release plate mounts a stop member aligned with said trackway.