US2491714A - Tape drying system - Google Patents

Description

ec. 2U, 1949 E. J. CARTER 2,491,714

TAPE DRYING SYSTEM Filed Jan. 29, 1947 s Sheets-Sheet 1 E E 'z A'owxreo J (3 7.62%?

ec. 20, 1949 E. J. CARTER TAPE DRYLTNG SYSTEM 3 Sheets-Sheet 2 Filed Jan. 29, 3,947

hys'fzfar T EDWHED (I (R6727? 1949 E. J. CARTER TAPE DRYING SYSTEM Filed Jan. 29, 1947 Ezra z; [57'' [aw/7 30 JCFzTE/e b 7 W Him.

Patented Dec. 20, 1949 TAPE DRYING SYSTEM Edward J. Carter, New York, N. Y., assignor to William M. Scholl, Chicago, Ill.

Application January 29, 1947, Serial No. 724,946

6 Claims.

This invention relates to apparatus for continuously drying a wet tape and particularly to a device for drying an elongated sheet or tape coated with a composition containing a volatile liquid. The invention further pertains to a method for drying wet tapes.

Heretofore, tapes or the like wetted with a volatile liquid have conventionally been dried by a method including conveying the tape through a relatively long tunnel-like chamber while circulating heated air through said chamber. Such a device not only occupies a considerable amount of space but the tape, when so dried, tends to wrinkle, curl or warp.

I have now provided a tape drying apparatus comprising an enclosure provided with a plurality of gen rally parallel rollers or bars disposed in two or more intersecting planes. More specifically, the rollers or bars are equally distributed between four series arranged in each of the four diagonal directions from the center of a cabinet of generally rectangular cross section. In each series, the rollers or bars are similarly spaced from one another, and each roller or bar has its two ends disposed approximately equidistantly from the cabinet center. Three series of rollers or bars are spaced equidistantly from the cabinet center, but the fourth series is additionally displaced outwardly and to one side by a distance preferabl corresponding to th spacing of the rollers or bars within each series. In other words, the rollers or bars are distributed symmetrically about the center of the cabinet in three diagonal directions but offset outwardly and to one side in the fourth diagonal direction by a distance comparable to the spacing of the rollers or bars within a series of roller-s or bars. As a result, a tape to be dried can be pulled over the outsides of all these rollers or bars along a convolute meanclrous path repeatedly crossing the diagonals of the drying cabinet so that the tape continuously passes from a roller or bar in one series to a roller or bar in another series. In effect, any one part of the tape, when moving,

follows a continuous line made up of consecutive more or less straight lines joining each other at approximately right angles at points falling on a spiral originating at the center of the cabinet.

The cabinet or enclosure is also provided with means for circulating air therethrough, and if desired with means for heating part or all of the interior of the cabinet or enclosure. The cabinet or enclosure may be subdivided into outer and inner concentric compartments of which one is other, so that the tape may first be exposed to drying atmosphere having a relatively lower temperature than the drying atmosphere to which the tape is subsequently exposed. Instead of providing heating means within the cabinet or enclosure, I may also arrange for the circulation of heated air therethrough.

The above disclosed tape drying apparatus is exceedingly compact and while occupying but little space permits the continuous drying of a wet tape by the exposure at one and the same time of a long expanse of tape to a drying atmosphere. Further, while the long expanse of tape is being dried, the tape is repeatedly broken or creased transversely (when passing over the rollers or bars) which serves to prevent the maintained at a higher temperature than the wrinkling, curling or warping that would otherwise occur on evaporation of a volatile liquid wetting the tape, and in particular when such evaporation causes contraction of a coating composition applied to the tape.

It will be understood that when the wet tape is pulled over the rollers or bars in my drying apparatus, the tape forms a number of spaced upper horizontal runs moving in one direction, spaced lower horizontal runs moving in the opposite direction, spaced vertical runs on one side moving upwardly and spaced vertical runs on the other side moving downwardly. The horizontal runs tend to sag, being supported or held in position by the rollers or bars only at the ends thereof. Such sagging may cause one horizontal run to contact another horizontal run, with consequent adherence due to the adhesive properties of any coacting composition applied to the tape. The coated surface of the tape is necessarily turned outwardly, so that the uncoated surface will contact the rollers or bars. Hence, the coated tape surface forms the lower side of the tape in the lower horizontal run and the upper side of the tape in the upper horizontal run. To space these horizontal runs and prevent contact and adherence, I provide rollers or bars supporting the 'upper runs and other rollers or bars serving to stretch, bulge or belly the lower runs downwardly.

It is therefore an important object of the present invention to provide a tape drying apparatus including an enclosure provided with rollers 01' bars over which a wet tape may be pulled along a line winding about a central point in said enclosure and either receding from or approaching toward said point whereby a longer space of tape may be dried at oncewithin a small space.

Another object of this invention is to provide a tape drying apparatus of the construction in- I 3 dica-ted in which said rollers or bars break or crease the tape transversely at frequent intervals whereby wrinkling, curling or warping is pre vented.

. Still another object of the invention is to provide apparatus of the construction disclosed and including means for supporting the upper horizontal tape runs having a coated surface turned upwardly together with means for stretching or bulging downwardly the lower horizontal runs having a coated surface turned downwardly whereby contact and adhesion between the horizontal runs is prevented.

A further object of the present invention isv to. provide apparatus of the construction indicated and subdivided into inner and outer concentric compartments maintained at different tempera tures so that the tape may first be exposed to a drying atmosphere having a temperature relatively lower than the dryingatmosphere to which the tape is subsequently exposed. 7

Another objectof the invention isto provide a method for drying a tape including the step of advancing said tape through one or more drying z e apnea mere c ises. ti i ar n i e ing frequent angular turns in the same transverse direction with respect to said tape while spacing the horizontal portions of said tape to prevent contact and adhesion therebetween, the drying temperature preferably being raised as the tape is adyanced. A a H 7, 7 v V Qtherland further objects andfeatures of the present invention will become apparent from the following description andappended claims.

The drawings show, diagrammatically and by way of example, two forms of drying apparatus according to the present invention. More particularly: m H v Figure l is a side elevational view, with parts broken away, of one drying apparatus according to the present invention;

Figure 2 is a; transverse vertical cross-sectional viewgof the apparatus of Fig. 1 taken along the line II II of Fig. 3; Y

Figure; is a longitudinal vertical cross-sectional viewof the, apparatus of Fig. 1 taken along the line III- III of Fig. 2; parts being shown in elevation, and other parts being omitted, in particular the blower and ducts shownin Fig. 1; and

Figure l is a- View similar to Fig. 3 but showing another drying, apparatus in accordance with the present invention; .The drying apparatus shown in Figs. 1', 2 and 3 comprises a drying cabinet generally indicated at H], and includinga top wall I, a bottom wall I2, a left side. wall |3,;,a right side wall l4, a rear wall l and a front wall I6. The front and rear walls I5 and I6 are pierced by aligned windows delimited by angle irons Hill and Hill. It will be noted that these two windows are equidistant from the side walls I3 and |4 bu.t slightly closer to the top wall than to the bottom wall 12.

Diagonally disposed on the inside of each of the walls l5 and I6 are angle irons 28 (upper left), 2|, (upper right), 22 (lower right) and 23 (lower left). The angle irons 20'; 2|; 22 and 23 extend diagonally with respect to the widows l5'a and lta and with respect to the walls l5 and IS. A num. ber of bearings 25 are provided on each of the angle irons 20, 2|, 22 and 23. More particularly, the angle irons 2| 22, and 23 each support six bearings, each set of six hearings being spaced diagonally in the same manner. The angle iron 29, however,- carries only five bearings disposed, with respect to height, at the level of the five innermost bearings on the angle iron 2|, and with respect to displacement to the left, as far out as the five outermost bearings on the angle iron 23. To each bearing supported on the wall l5 by an angle iron there is opposed, in exact alignment, another bearing supported from the wall l6 by another angle iron. Each pair of opposed bear ings accommo dates the shaft of aroller 25 extending transversely across the interior of the cabinet |0. Vertically disposed on each of the walls l5 and I6 approximately midway between theangle irons 22 and 23 is an angle iron 21 provided with bearings 28 for supporting the shafts of rollers 29 extending transversely across the interior of the cabinet Ill. The series of rollers 29 supported from the angle irons 21 are offset downwardly with respect to the rollers 26 supported from the angle irons 22 and 23. On each of the walls l5 and I6 there is also disposed an iron plate 30 extending vertically midway between the angle irons 20 and 2| and providedwith bars 3| 6n the sal ne 1 e1 as the rollers 26 supported from the angle iron 2|.

The cabinet I U is subdivided into an outer compartment and a concentric inner compartment 36 by joined partition walls 31 (upper horizontal), 38 (left vertical) ,3!) (right vertical) and 40 (lower horizontal). These. partition walls are afiixed to the angle irons 2|, 22, 21 and 23 between the three inner and the three outer rollers on said angle irons and to the angle' iron 20 between the two inner and the three rollers thelOil. Since the rollers 29 on the angle iron 21 are offset downwardly with respect to the rollers 26 on the angle irons 22 and 23, the partition wall 46 is bent downwardly to a slight extent at its middle.

H The partition wall 38 is pierced by a horizontal slot at the level of the outermost of the three rollers 26 supported from the angle iron 2| within the inner compartment 36. The left side wall I 3 of the cabinet H1 is pierced by a horizontal slot 46 at the level of the outermost of the rollers 26 supported fromthe angle iron 2|. Outside the slot 46, a roller 41 is supported from the side wall l3 by a bracket 48 provided with suitable bearing means, at the level of the outermost mm 26 supported from the angle iron 2| The inner compartment 35 contains within the area between the windows defined by the angle irons |5 a and 56, a laminating device including, affixed to each angle iron |5d and Ilia, a supporting member fo'r'med with. a horizontal portion 50, an erect memb'erBI extending from the right end of the memb er 5G, erect member 52 extending from the left end or the member as, and anllpi er horizontal portion 53 extending inwardlyfrom the top of the member 52. The free end. of the member 5| is provided with suitable bearing means for si l pbiti 'ie a roll 54 of paper tape 55 to unwound therefrom. The middle of the member 53 provides suitable bearing means for supporting a roll 56 of permeable paper tape 5? to be unwound therefrom. From the roll 54; the tape 55 passes under a bar 53; over a bar 59, past a distributor 60 for a liquid adhesive composition, between a pair of rollers E i and between a second pair 'of rollers 62. The permeable tape 5i passes from the roll 56 over a bar 63 and between the rollers 82 for s uperposition upon a layer of ad hesive spread over the tape 55 by distributor 89; From the roller 62,- the resulting laminate (tape 55, adhesive. tape 5?) passes between a pair of ioner's at and thr'eug'h ahadjustable tensioning device 65 that serves to force the adhesive up through the tape 57 so as to form a layer of adhes'ive on the upper surface of said permeable 62 and 64. This laminating device is disclosed and claimed in my application entitled Coating apparatus, Serial No. 724,947, filed of even date herewith. Reference is made to said application for a detailed description thereof. The method of making the tape is more particularly disclosed and claimed in my copending application, Serial No. 767,162, filed August '1", 1947, entitled Method of making adhesive tape.

From the roller ID, the tape passes over the outside of the innermost roller 26 supported from the angle iron 23, thence over the innermost roller 29 supported from the angle iron 21, over the innermost roller 25 supported from the angle iron 22, the innermost roller supported from the angle iron ZI, the innermost bar supported from the plates 39, the innermost roller supported from the angle iron 29, the next to the innermost roller supported from the angle iron 23, and is thus advanced counterclockwise over all the rollers within the cabinet Ill. In the course of this ad vancernent, the tape passes through the slot 45 in the partition wall 38 and finally emerges from the cabinet I9 through the slot 45 in the side wall I3, passing thereafter over the roller 41. During this advancement, the volatile constituents of the coating composition is evaporated off. For

facilitating such evaporation, the present device is provided with air circulating and heating means described hereinbelow.

As shown in Fig. 1, there is mounted on top of the cabinet I!) a suction fan driven by a motor 16 and connected through a curved conduit I1 with both cabinet compartments 35 and 39 (between the top wall II and the upper edge of the angle iron I5a) for removing from these compartments air containing vapor derived from the coating composition. Further, heating means are provided at the bottom of the cabinet Ii! of any suitable or conventional type for heating the outer compartment 35 or for introducing hot air thereinto. By way of example, I have shown a heating device comprising a chest 80 extending lengthwise of the cabinet II) over the bottom I2 thereof. The chest has its left-hand longitudinal side wall 8! pierced by a longitudinal horizontal slot 92. Further, the side wall BI has attached thereto a longitudinal box-like member 83 communicating with the interior of the shaft 89 through the slot 82 and receiving air from open ended air pipes 84. The air passes from the member 83 through the slot 82 into and through the chest 80 and out from the chest 80 through a longitudinal slot 85 in the top wall of the chest at the right-hand side thereof. During this passage, the air is heated by a steam coil 86 having fins 81 attached thereto. Bailles 88 are provided between the turns of the steam coil.

It will be noted that in the apparatus of Figs. 1, 2 and 3, air is circulated through both compartments 35 and 36, but that only the outer compartment 35 is heated directly. The movement of the tape being from the middle of the cabinet through the inner compartment 35 and then through the outer compartment 35, the tape is first exposed to a drying atmosphere relatively less warm than the drying atmosphere to which the tape is subsequently exposed for final drying.

From the cabinet I0, the dried tape passes over angle irons gamma the roller 41 to any suitable conventional reeling mechanism, for instance that shown in the drawings as supported by bracket means 99. More particularly, the tape may pass over rollers 9| and 92 supported from a standard 93 rising from the bracket 99, and thence over one roller 94 for winding up on a roll 95 rotatively supported by the roll 94 and another parallel roller 96 spaced slightly from the roll 94. The roller 96 is driven from a motor 91 by means including a speed reducer 98 and a belt and pulley system 99. The roller 94 is driven from the roller 96 by belt I09.

The reeling or winding up mechanism receiving the dried tape for forming the same into a roll, no matter of what construction, supplies the force for unwinding the tape 51 and 55 from the rolls 5B and 54 and for pulling the tapes 55 and 51 and the lamination produced therefrom through the apparatus of Figs. 1, 2 and 3.

In Fig. 4 I have shown another apparatus according to the present invention generally similar to that shown in Figs. 1, 2 and 3 but differing therefrom in having the tape to be dried moving from a coating device outside the drying cabinet and then clockwise along a convolute path through the cabinet to be wound up into :roll form at the center of the cabinet. As shown in Fig. 4, this drying device includes an enclosed cabinet Ill} slotted horizontally in the upper left side wall, as at III. The front and rear walls are apertured, and the apertures are delimited by angle irons such as the one shown at I I2. Angle irons I I3 and I I4 extend diagonally in the upper left and right corners, respectively, of the front and rear side walls. Other angle irons. II5 and I I 6 extend diagonally, with respect to the windows or apertures defined by the angle irons H2, to points spaced approximately half way between the vertical side walls of the cabinet III) and the angle iron IIZ. Other angle irons. Ill and H8 extend diagonally with respect to the lower right and left hand corners of the cabinet llll, from points aligned vertically with the outer ends of the angle irons I I5 and I It. The ends of M the angle irons H5 and II! as well as the ends of the angle irons H6 and H3 are joined, respectively, by vertically extending bars H9 and I29. The angle irons H3 and H4 and the bars H9 and I20 support a partition wall I25 subdividing the cabinet IIll into an outer chamber I26 and an inner concentric chamber I21.

Each of the angle irons H5, H6, Ill and H8 is provided with three bearings I30 accommodating the shafts of rollers I3I. The angle iron H4 is provided with six bearings I32 for accommodating the shafts of rollers I33, while the angle iron H3 is provided with five bearings 35 for supporting the shafts on five rollers I35. As shown, the rollers of the angle irons I It and II! are disposed within the outer compartment I26, as are also the three outermost rollers of the H3 and H4. The rollers on the angle irons H5 and H6, the three innermost rollers on the angle irons I I4 and the two innermost rollers supported from the angle iron II 3 are disposed within the inner chamber I21. To space the upper horizontal runs of tape, I have provided, midway between the angle irons H3 and H t, a vertically extending bar I45 on each of the front and rear sides of the cabinet for supporting bars I4I extending transversely across the cabinet at the level of the rollers supported from the angle iron H4. For spacing the lower horizontal runs of tape, a vertical angle iron I42 is attached to each of the front and rear asap-r14 walls of the cabinet and accommodates, in bearings M3, six rollers N4 of which the three upper rollers are offset downwardly with respect to the rollers n the angle irons H5 and H6 while the lower three rollers M4 are ofiset downwardly with respect to the rollers of the angle irons Ill and I I8.

i In the apparatus of Fig. 4, tape I59 unwound from the roll 85! is coated with adhesive from a distributor 552 and has superimposed thereon a permeable tape [53 unwound from a roll I54. The resulting structure (tape I56 coated with adhesive and having tape 1-53 superimposed upon the adhesive) passes through an adjustable tensioning device I serving to force the adhesive upwardly through the tape I53 and to form a distinct layer on top thereof. This laminating mechanism is essentially similar to that shown in Fig. 3 and described in detail in my said application filed of even date herewith. The whole laminating mechanism of Fig. 4 is supported from the left side wall of the cabinet H!) by means of the bracket 55. The laminate formed as described passes from the tensioning device I55 over a roller 55 supported from the left side Wall of the cabinet ill} by bracket H38 provided with suitable bearing means at a level slightly below that of the tensioning device l55. From the roller 15?, the laminate passes over roller 15;; supported by a bracket 160 provided with suitable bearing means .from the left side wall of the cabinet Ht. From the roller I59, the laminate passes through the slot H I into the outer chamber 128 of the cabinet I Ill, over the outermostroller supported from the angle iron il and then passes, in a clockwise direction, along a winding path over the three rollers supported from the angle iron H'i, the three rollers supported from the angle iron H8, the three outermost rollers supported from the angle iron l3 and the two remaining rollers supported from the angle iron H t within the chamber I26. .Havi-ng made three complete turns around the outer chamber I25, the tape next passes through a slot 162 in the upper left-hand side wall "of the partition at the level of the innermost roller ion the angle iron H3 within the chamber I26, to make two and a half turns about the middle of the cabinet within the inner chamber 121. As

shown, the tape passes over the two innermost rollers on the angle iron N3, the three innermost rollers supported from the angle iron H4 and the rollers supported from the angle .iirons l I5, 1 It and 52. After-leaving the innermost rollers the angle mm the tape passes Over a along a path winding through saidcompartments :roller not supported from the front and side Walls of the cabinet by bracket means 166 provided with suitable bearing -means. Theroller 5 is disposedslightly above the innermost roller on'theang-le iron l lfiyto permit the advancement "oi the tape to a winding or-ree'ling mechanism "disposed in the middle of the cabinet and sup- Jported by suitable means, fcr instancegirom the angle iron iii and the ether ang-1e iron (not shown) defining the two apertures in the front and rear walls of the cabinet Ht.

Mo're particularly, the reeling mechanism includes two 'spaced rollers i537 and l'iiii'driven fromla motor "5% by belt iii and supporting =therebetweena roll '1?! on which the tape is wound up. Itshou'ld ;passes through the outer chainber 4-25 and l the inner chamber 121.. For this purpose, exhaust means are provided (not shown in the drawing) for evacuating the outer chamber I26 and the inner chamber I21. These means may be essentiall similar to those shown in connection with the device of Figs. 1, 2 and 3. Air is admitted into the outer chamber I26 through an extended horizontal slot I75 in the bottom part of the rear wall. Hot air is provided for the inner chamber l'2-l by means including a chest I76 disposed on the bottom of the chamber I21. Air under pressure is admitted to this chest through air inlets IT! and circulated within the shaft around a steam coil 118 provided with fins ill], the air then being admitted into the inner chamber 1 21 in a manner essentially similar to that described in connection with the heating device of Figs. 1, 2 and 3.

It will be noted that both the embodiments of the present invention disclosed in detail hereinabove include means for coating 01- wetting one surface of a tape; means for winding up the coated or wetted tape after the same has been dried; drying means for said 'tape disposedabout either the coating Or wetting means or about the reeling means and arranged for advancing the wetted or coated tape repeatedly around either the coating or wetting means or around the reeling means; and means for spacing the horizontal runs of tape established in said drying means to prevent contact and adherence between the runs. Further, the drying means may be subdivided into 'a preliminary drying zone maintained at a lower temperature than a final drying zone.

Many details of construction and procedure may be varied within a Wide range without departing from the principles of this invention and Without sacrificing the advantages disclosed hereinabove, and it is, therefore, not my purpose to limi't'the patent granted on this invention otherwise than necessitated by the scope of the appended claims.

I claim as my invention:

7 1. Apparatus for drying tape comprising a cabinet, a partition wall within said cabinet subdividing said cabinet into first and second concentric compartments, means for flowing air through said compartment into which said tape -is first in'trodu'ced'to elfectinitial partial drying of the same, means for flowing-heated air through the second compartment to substantially comiplete the drying of pre-dried tape introduced therein from said first compartment, -a plurality of rollers disposed within said cabinet transve'rsely thereof over which sa'i'dtape can be pulled about a central point in said cabinet, means for :Spacing opposed horizontal tape portions being advanced-over said rollers to prevent contact and adherence 'of said opposed tape portions, and means operative to pullsaid tape over said rollers.

'2. Apparatus :ior drying a wetted tape compris'ing "an enclosed :generally rectangular cabiinet having two opposed side walls pierced by aligned windows, partitionwallimeans subdividing said cabinet :into concentriczinner and outer compartments, means Jim-introducing hot air into the outer compartment, suction means for :with- :drawing .air from said two compantments, 'a'pluduality of :rollers disposed within said cabinet :transversely thereof .at .points falling on a spiral l=line originating from acentral point within said :cabinet, said :rollers being distributed between said two compartments and being arranged as four series of rollers each :extending diagonally with respect to saidicabinet-sothatsaid tapeacan be guided over said rollers to form a plurality of upper horizontal runs distributed between said two compartments, a plurality of lower horizontal runs distributed between said two compartments, a plurality of left-hand vertical runs distributed between said two compartments and a plurality of right-hand vertical runs distributed between said two compartments, said partition wall being slotted to permit one horizontal tape run to extend from said inner compartment to said outer compartment, said cabinet being slotted to permit one horizontal tape run to extend from said outer compartment to the outside of said cabinet, means for sup-porting said upper horizontal runs within said two compartments to prevent sagging of said runs and contact therebetween, roller means, within said compartments for stretching said lower horizontal runs downwardly to prevent adherence therebetween, means for introducing a wetted tape into said inner compartment, and means outside said cabinet for forming the dried tape into a roll, said last mentioned means being operative to pull said tape through said apparatus.

3. Apparatus for drying a wetted tape comprising an enclosed generally rectangular cabinet having two opposed side walls pierced by aligned windows, partition wall means subdividing said cabinet into concentric inner and outer compartments, means for introducing hot air into the inner compartment, suction means for withdrawing air from said two compartments, a plurality of rollers disposed within said cabinet transversely thereof at points on a line winding about a central point within said cabinet and receding therefrom, said rollers being distributed between said two compartments and being arranged as four series of rollers each extending generally diagonally with respect to said cabinet so that said tape can be guided over said rollers to form a plurality of upper horizontal runs distributed between said two compartments, a plurality of lower horizontal runs distributed between said two compartments, a plurality of lefthand vertical runs distributed between said two compartments, and a plurality of right-hand vertical runs distributed between said two compartments, said partition wall being slotted to permit one horizontal tape run to extend from said outer compartment to said inner compartment, said cabinet being slotted to permit one horizontal tape run to extend from outside said cabinet into said outer compartment, means for supporting said upper horizontal runs within said two compartments to prevent sagging of said runs and contact therebetween, roller means within said compartments for stretching said lower horizontal runs downwardly to prevent adherence therebetween, means outside said cabinet for introducing said wetted tape into said outer compartment, and means within said inner compartment for forming the dried tape into a roll, said last mentioned means being operative to pull said tape through said apparatus.

4. Apparatus for drying a wetted tape comprising an enclosed cabinet, a partition wall dividing said cabinet into concentric compartments, a plurality of rollers disposed within said cabinet and extending transversely thereof over which said tape can be pulled along a path winding tion fan, means for driving said fan and a conduit connecting said fan to each of said compartments, a vent in that compartment into which the tape is initially introduced for introducing air into said compartment to efiect partial drying of the same, and means for introducing heated air into a second compartment to substantially complete the drying of the tape, said last-mentioned means including a conduit for supplying air, a heating element over which said air is passed to heat the same and means for introducing said heated air into said second compartment.

5. Apparatus for drying a wetted tape comprising an enclosed cabinet, a partition wall dividing said cabinet into concentric inner and outer compartments, a plurality of rollers disposed within said cabinet extending transversely thereof over which said tape can be pulled along a path winding through said compartments about a single point within said cabinet, suction means for withdrawing air from said inner and said outer compartments including a suction fan, means for driving said fan and a conduit connecting said fan to each of said compartments, a vent in said inner compartment open to the atmosphere for introducing air into said inner compartment to effect partial drying of the tape passing therethrough and means for introducing heated air into the outer compartment to substantially complete the drying of the tape from said inner compartment, said last-mentioned means includin a conduit for supplying air, a heating coil over which said air is passed to heat the same and means for introducing the heated air into said outer compartment.

6. Apparatus for drying a wetted tape comprising an enclosed cabinet, a partition wall dividing said cabinet into concentric inner and outer compartments, a plurality of rollers disposed within said cabinet extending transversely thereof over which said tape can be pulled along a path winding through said compartments about a central point in said cabinet, suction means for withdrawing air from said compartments including a suction fan, means for driving said fan and a conduit connecting said fan to each of said compartments, a vent for said outer compartment open to the atmosphere for introducing air into said outer compartment into which the tape is initially introduced to effect partial drying of the same and means for introducing heated air into the inner compartment to substantiall complete the drying of the tape passing therethrough from said outer compartment, said last mentioned means including a conduit for supplying air, a heating coil over which said air is passed to heat the same, and means for introducing said heated air into said inner compartment.

EDWARD J. CARTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 703,044 Crowell June 24, 1902 772,695 Crowell Oct. 18, 1904 1,838,480 Gangler Dec. 29, 1931 1,956,062 Duvall Apr. 24, 1934 2,376,207 Tetzlaff et a1. May 15, 1945 2,448,854 Begum e Sept. 7, 1948

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