US 2606853 A
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Description (OCR text may contain errors)
g- 12, 1952 T. s. REESE ET AL ,606,853
DRY STRIP TRANSFER, METHOD OF USING SAME, AND ARTICLE PRODUCED THEREBY Filed Jan. 18, 1951 .DECOEA 7'/VE Z YEP STE/PP/NG (A YEP CIA) COAT/N6 MACH/NE FIN/SHED FA FEE MACH/NE FIN/SHED FA FER WND co r l :%L 5/! 56 MA 7522/44 1 DECO A 7/ V5 L MACH/NE FIN/ShfD PA PE)? E A Y5K BA SE MA TEE/AL INVENTORS THO/1A5 REESE ALBA V/D 6/4110 WAY- ATTORNEX Patented Aug. 12 1952 EFICE 2,606,853 DRY STRIP TRANSFER, METHOD OF USING SAME, AnnAnTmL-E PRODUCED THEREBY Thomas s. Reese, University e ghts, and David G l w y, Euclid, Ohio, sisnors to The Di-Noc Company, Cleveland, Ohio, a corporation 'of' Ohio Appl a n a ua y 1 1 5. Serial No.- WM-.233.
, This invention relates to a dry-Stripping decorative transfer, to the method of making it, to the method of applying it, and to the product obtained by using it. Heretofore, standard commercial practice in the manufacture and use of decorative transfers has required preparation of the transfer in a manner allowing the temporary supporting material, usually paper, to be soaked with water preparatory to its removal, itself a messy operation demanding the exercise of considerable care. Because the use of water for this purpose often tends to damage the base material to which the transfer is applied, it has frequently been necessary to trim off the edges of the base material after what is called the transfer layer" has been consolidated with it and the paper removed. Decorative transfers of this kind are rather expensive to make, difficult to handle, and often subject to uncontrollable dimensional changes as a result of changes of temperatur humidity and other applicable factors.
In general, commercial practice in connection with the manufacture of such decorative trans,- fers involves the use as a temporary carrier of a special non-sized paper known as water leaf, which, for the reason that it is a paper'for which there is only a limited demand, ismore expensive than conventionally sized machine-finished papers. In practice, one side of the paper is coated with a layer of starch followed byvarious coatings of dextrin, after which the desired decoration is coated or printed on the dextrin coating. The transfer layer, which is applied to the decoration with or without a background color, is usually applied in the form of a nitrocellulose, ethyl cellulose or acetyl cellulose lacquer. The
transfer as a whole is then brought into contact with the base material, which is prepared by applying to it a preliminary coat in which, if the transfer is not itself colored, may be incorporated the color that characterizes the finished product. Thereafter the paper is removed by wetting it and stripping it off, following which the assembly is baked or permitted to air-dry, depending on the materials employed.
In general, processes for making and applying transfers of this general type are disclosed in prior Patents 1,627,407, 1,924,961 and 1,982,927, all granted to Thomas S. Reese.
The present invention has for one of its 'principal objects to eliminate disadvantages which attach to the manufacture and use of transfers of the kinds described in the above-identified patents. Among other things, ,it contemplates the manufacture andv use of a idry-stripping decorative transfer which, by'virtue of the nature 20 Claims. (Cl. 15 .795
of thefmateltials which make it 11p, is relatively free from dimensional instability, excessive sensitivity to humidity, and the common tendency to shrink a d cause pap r t cu l. To t is e d,
the invention makes use of two more or. less incompatible resinous layers, one of them being laid down on the other, between which the separation is effected when the dry-stripping operation is performed.
O he objects and adv ntages, o the i v t o will be apparent from the followi de on and from the accompanying sheet .ofdra'wings, in which Figure 1 shows in diagrammatic fashion a transfer made up in accordance with the present invention; Figure 2 shows in s hematic fashion how the transfer is applied to a base material; Figure 3 shows in like schematic fashion the manner in which the paper is detached, the same being intended to illustrate the operation of dry-stripping; and Figure 4 shows a method and means for applying the transfer and removing the paper in a commercial operation, the showing in Figure 4, like that of Figure ;1,5heing diagrammatic. l g V According to the invention, in lieu of unsized paper such as water leaf, there i -empl yedfor the temporary carrier a sized machineefin'ished paper, usually apape'r :made by oneof the ordinary mechanical or chemical pulping processes, con a nin a small amount of a conventional size of casein, rosin or the like thatis added to the pulp togive the paper strength and dimensional stability under va yin c nditions of hu i t Preferred for the purposes of the present invention'is ,a smooth surfa'ce'd calendered 'paperhavinsv a stretch of about 1% as measured b a Mullin tester, a breakingstrength-of about 20 lbs. per square inch, and a thickness of about 0.004 inch. Prefe a y, bu not ecessarilyg suc pape is finishecoated .on one or both sides with finelydivided kaolin v(china o1ay,) ,'-whitin g or the like.
Papers so .finished are available on the market and, as a rule, it is therefore not- -neces sary,for the .mannfacturerof the transfer to ,apply a:fln ishingcoatto the paper; indeed,if ent, he may, if desired, do withoutit.
To paperof this kindwith or without the hpishing coatwhat may :be calle d a stripping layer i applied by laminating, knifer preading, roll.- coatingyreverse roll-coating, ,brushing' or" sprayinsso as to provide o form althin loathrefermaterial taking the form of a vinyl halide polymer. The latterpreferably consists of a polymer of vinyl chloride or a co-polymer of vinyl chloride-and vinyl acetate. If 5 desired, thefilm-form An organosol is an example of a composition that may be used for the layer of resinous. film,- forming material. It mayconsist of a resin, a
plasticizer and one or moreisolvents; which" in a typical case may be present in these propertions: as resin, polymerized vinyl chloride (solids) 65%; as plasticizer, dioctyl phthalate, 52% of resin content; and as solvents,smethyl ethyl ketone or the like diluted with toluol, xylol or a petroleum fraction, 35% of resin content. Before application, which may be at room temperatures,
the organosol has a'fusion temperature of about 350 F. (3 minutes). C ompositions'of this general type are made and sold byyarious manufacturers. Among the available i-"o'rganosols are Ultrasol L-6763 and Ultrasol L-68518, made by Monsanto Chemical Co. (Plastics Division); The former, which has a viscosity of 2600 centipoises, ispreferred for th purposes of the invention.
Another example of a coating composition suitable for these purposes makes use of the'copolymer of vinyl chloride and vinyl acetate made by Bakelite Corporation and sold under the trademark Vinyl Resin VYHH. The latter, which takes the form of a white powder,'c'onsists by weight of about 87% vinyl chloride and about 13% vinyl acetate. In formulating the coating composition, 62 pounds of the powder-are mixed with 94.5 pounds of acetone, 63 pounds of methyl isobutyl ketone and 157.5 pounds of 'toiuol; to yield approximately 51 gallons of a composition which has a solids content of 16.6% by weight. It has a viscosity bythe Ford cupmethod of 23 seconds at 72F. and can be applied at ordinaryroom temperatures.
4 stripping layer. The second layer, by contrast with the first, is separable from the paper and constitutes the transfer layer.
The thickness of the transfer layer must be sufficiently to cover the stripping layer adequately and may vary between about 0.0003 and about 0.0010 inch after elimination of the solvents.
'By way of example of a coating composition 5 that may be applied at ordinary room tempera- I;
tures to formthe transfer layer, one may knifespread, brush, spray or roll-coat onto the strip- ,ping layer a mtrocellulose lacquer such as the following:
Parts Ingredients by weight Nitrocellulose, RS1/2 (falling ball method) 15.00 Blown Castor i1 7. 60 3. 50 14.00 7. 50 3. 75 3. 75 45. 00
sun a third example involves calendering or otherwise laminating a film of a vinyl chloride polymer or copolymer having a thickness of about 0.0005 inch to paper of'thedesired characteristics; e. g., uncoated machine-finished paper, to provide a stripping layer on one side thereof.
' Whether the stripping layer be of one of the above-described formulations or of some other formulation,'it is usually desirable to allow the film so applied to harden before proceedingfurther. To this end, the coated product may-be run through a dryingtunnel through which is passed a current of air at an elevated temperature. Thereafter the product may be passed in known fashion over drums to cool and wind it.
After the stripping layer has hardened, by which time it should have become so tenaciously attached to the paper orto the finishing coat on the paper that for practical purposes it is inseparable from it, the next step is to lay down on the stripping layer a colored or uncolored layer of resinous film-forming material of such nature that the layer is largely incompatible with the previously applied stripping layer. The incompatibility may be varied as desired within rather broad limits but should not extend so far that the second layer of film-forming material will not adhere satisfactorily tothe first layer; rather, there should be enough adherence to permit the transfer as a whole-to be handled as a unit but not so much as to preclude easy separation and removal of the paper and the associated Similarly, as indicated in the following formulation, it is possible to use a coating composition in which the solid residue consists largely of cellulose acetate:
Such composition likewise may be applied at ordinary room temperatures.
Cellulose others may be employed in lieu of cellulose esters as indicated by the following formulation, f in which ethyl cellulose is similarly used and applied;
Lacquers containing polyvinyl acetals may likewise be used, as indicated by the following formulation based on polyvinyl formal:
, Parts Ingredients by weight PolyvinylFormal 1 15.00 Butanol 5.00 Ethyl Alcohol (denatured). 25.00 Toluol, 55. 00 Dibutyl Phthalate 2. 50
, ThepoIyVinyI formal should be one of low viscosity and low hydroxyl content: i. e,, the hydroxyl content (as polyvinyl alcohol) should be from 5 to 7 on the transfer layer when A formulation in which used for "these purposes is the following: A,
Ingredients The polyvinyl bu t yral should be of the high-viscosity type: 1-- en ipei es (T /1% 9 l l methanol at .C.)
As a rule, the various polyvinyl acetal lacquers may be applied to advantage at ordinary room temperatures; e. g.,' 72 F. i
As will be observed from the live preceding formulations, all of these coating compositions contain large amounts of volatile solvents to be eliminated. Thisis best done at somewhat elevated temperatures, particularly under circumstancesin which the recovery-of the-solvents is contemplated. "A process of hardening similar to that described above in the case-ofthe coating composition used to form the stripping layer may be employed for the purpose.
Once the transfer layerhas been allowed to harden, it is possible to imprint on the transfer layer was to form a decorative layer, preferably by using a medium compatible with the materials of which the transfer layer is formed. By im printing, reference is had to the production of a continuous or discontinuous design, as 'by'means of an appropriate plate or roller, with or without the use of ink. The decorative feature that is to form part of the transfer as a whole is usually formed in or on the transfer layer but may in "some cases be formed in or on the stripping layer in such manner that it will adhere to and remain the separation of the two layers is accomplished.
When lacquers of the types described above are employed for forming the transfer layer, a lacquer-like ink may be used for printing. By way of example, such ink may have the following formulation:
, .Parts Ingredients by weight Carbon Black 3.00
. Nitrocellulose, to centipois 10.00 Dibutyl Phthalate 4. 00 'Etbyl Acetate l 3. 75 Butyl Acetate 9.50 Butyl Alcohol- 3. 75 Toluol '21. ()0
(Norm: The above ingredients are ground together in a ball mill.) v
If, as is contemplated, the ink is to be employed at a temperature of about 72 F., a very thin film, not more than .0001 inch in thickness, should be applied to the transfer layer.
It is also practicable to interchange the materials used for the stripping and transfer layers,
polyvinyl butyral is at on h a s-o a vinyl h d olym r. e pclymer of a vinyl halide andvinylacetate, or a material; of similar physical characteristics and h c Dra eries. th is inw a blewi th residue; of the previously'applied lacquer.
, In the latter case the decorative layer should o u s b m ti e with. t v y al d polymer or copolymer. It may be compounded as indicated in the following formulation:
' Parts by weight 1. inseam 19502013: The above ingredients are ground in a pebble 1 r Although factory practice does not always require zitaa colored oruncolored. clear) surusing the lacquer coating as the stripping layer laid down on the paper or on the finishing coat on the paper. Any of the formulations given above for the lacquer will serve the purpose, giving rise to in such case what has been referred to as the inseparable layer of resinous film-forming material. In such case, the transfer layer; that. is to say, the separable layer of resinous filmforming material, will take the form of one of the compositions mentioned above as formuface coating of the same family of materials may be applied to the exposed face of the transfer to obviate'damage to the decorative layer during storage, v f
In practice, the transfer .is applied. to .a base material whichha's 'beenprepfared by applying to it a clear or colored preliminary coat, hereinafter referred to as a ground coat, that is similar to or at least compatible with the material of the surfac'e'layer cf the transfer. The ground coat may advantageously incorporate the colorant, if any, used to impart the desired color to the final product; however, if the transfer itself carries the colorant, the ground coat will ordinarily be uncolored. The ground coat may conveniently take the form of a tacky liquid similar to those disclosed in prior Patent 1,924,961. Insuch case, it will include, along with one or more so'lidconstituents, a substancesusceptible of removal at somewhat elevated temperatures; for example, a relatively high-boiling organic solvent such as Butyl Cellosolve? .(butyl ether of ethylene glycol). I r
The basematerial is preferably a rig-id or relatively rigid material of any one of the wide variety of substances available for this purpose, including metaLglass, wood, hard board, paper board, or the like. V
A suitable formulation for application to a base material to form, aground coat of the tacky type is as follows: i
1 Dehydrated castor-oil'type of medium oil length.
As an alternative, it is possible to apply to the ase material a ground coat'ofthe nature of a nitrocellulose lacquer or some suitable similar composition that will dry by evaporation at room 7 temperatures; following it when dry by a welding solution that will have a softening or solvent, action on, but will not'toostrongly attack, both the ground coat and the surface layer ,or layers of the'transfer that is to be applied to it. If the transfer-is one containing a exposed layer "of the vinyl polymer such as vinyl chloride, a vinyl copolymer such as vinyl chloride-vinyl acetate, or a vinyl acetal such as vinyl formal, vinyl butyral or the like, the welding solution may advantageousl'y be formulatedto include Butyl Cellosolve, Ethyl Cellosolve or even Methyl Cellosolve; if, on the other hand, the exposed layer is of the nature of a nitrocellulose lacquer residue, the welding solution may advantageously be a mixture of equal parts of ethyl lactate and diacetone alcohol diluted with water.
The welding solution may be clear or colored, the former if the colorant is in the ground coat or carried by the transfer and the latter if neither one incorporates a suitable colorant.
The following is an example of a welding solution suitable for use in the case of vinyl compounds:
Ports Ingredients by weight Methyl Gellosolve Acetate (Ethylene glycol monomethyl ether acetate). l. 1.00 2. 00
Where a nitrocellulose or like lacquer is employed in forming the exposed layer of the transfer, the following is a suitable formulation for If desired, rather than apply the welding solution to the base material, it is possible to apply the welding solution, colored or uncolored, to the exposed layer of the transfer. v
The transfer is preferably applied intact to the base material, the side of the transfer revealing the decorative layer being brought into contact with the coating on the base material. This may be done by feeding the basematerial from one source and the transfer from a separate source to a common pressure zone where, using cooperating rolls, a pressure of about 500 pounds per square inch may be employed to apply the transfer to the base material. The effect of applying a pressure of this order of magnitude is to consolidate the ground coat, the decorative layer and the stripping layer, forming a composite which at this stage intervenes between'the base material and the paper comprising the temporary carrier for the transfer.
In this condition, the bond between the stripping layer applied to the paper and the transfer layer that forms part of the composite remains as before a weak bond permitting ready removal of the paper and the associated inseparable layer of resinous film-forming materials; i. e., the stripping layer. However, the step of stripping off the paper and the associated inseparable layer of resinous film-forming materials should not be attempted until the'whole has been subjected to the action of mild heat or permitted to stand fora sufficient length of time to bring about elimination of any excess solvent by slow evaporation at roomtemperaturesi Thereafter, the paper and the stripping'layer may be removed by dr'y st'ripping with; a modicum of force applied to one corner of'the paper by the fingers 8 or with the, aid of machinery designedfor the purpose.
After the paper has been stripped therefrom, the exposed transfer layer may, if desired, be spray-coated with a layer of clear lacquer or varnish to furnish a protective layer.
These operations are illustrated in the accompanying drawings. Figures 1 and 2 show a decorative transfer made up of a relatively thick layer l of machine-finished paper, a thin clay coating 2 applied to one face thereof, a thin stripping layer 3, a transfer layer 4, likewise thin as compared to the layer of paper, and a very thin decorative layer 5, which may or may not be continuous in and of itself but which is ordinarily co-extensive with transfer layer 4. As indicated in Figure 2, the decorative transfer shown in Figure 1 is applied, with the paper side up, to a relatively thick base material 6 having thereon a ground coat 1. After the application of pressure to form the composite which at this stage intervenesbetween paper layer l and base material 6, paper layer L'together with stripping layer 3 and the intervening clay coat 2, is removed by pulling it away from the transfer layer, which may bedone by grasping the paper layer I at one corner and continuing-to pull it uniformily away from the transfer layer 4.
The step of removing paper layer I, together with clay coat 2 and stripping layer, 3, need not follow immediately after application of the transfer to the base material; as a matter of fact, the base material with the decorative transfer applied and the paper layer still in place and intact may be routed, sawed or similarly worked before stripping is undertaken. The base material with the paper layer in place and intact may be shipped in that form, the paper layer i and the associated clay coat 2 and stripping layer 3 being removed by the consignee. The paper layer thus protects the decorative finish and prevents damage during fabricating operations. Alternatively, paper layer clay coat 2 and the associated inseparable layer of resinous film-forming material comprising stripping layer 3 may be removed as soon as the solvent has been eliminated from the ground coat, after which the spray coat of clear lacquer or varnish may be applied, if desired, and the product made ready for use.
In factory practice it is convenient to feed the base material, prepared as, described above, in the form of panels IO to a pressure zone such as that afforded by two co-acting rollers II and I2 rotating in opposite directions, the panels following one another through the rollers with substantially no intervening spaces. Simultaneously there is fed to the pressure zone from a separate source such as a roller 13 a continuous web M which is made up of a decorative transfer of the type shown in greater detail in Figure 1. As the panels l0 and web 14 move into the pressure zone, they are united by the action of rollers H and I2, which are preferably interiorly heated to drive off the solvents, after which the papei layer and the associated inseparable layer of resinous film-forming material, designated 15 in Figure 4, is picked up in the form of a, roll l6 or other compact mass lending itself to re-use. The panel to which the decoration has been applied in the manner described, designated ll, moves away from the pressure zone to be spraycoated with clear lacquer or varnish, allowed to dry, and used or stored.
By following" the practices described above,
. 9 there is obtained a decorative transfer'thatgis characterized by a high degree ofdim'ensional stability, a high degree ofresistance to the effects of heat,' humidity and'otheratm'ospheric factors, and a capacity for easy application to" a base-material. When the transfer as a whole is once applied to the base material, the paper or other substance forming the temporary carrier may be readily separated and removed by a dry-stripping operation, this by virtue of the incompatibility between the's'ep-arable and inseparable layers of resinous film-forming materials.- The stripping acoaees operation may be carried'out immediately or after the paper has been used to protect the finish during subsequent handling and fabricating operations. The need for 'apply'ing'wa'ter to=soak the paperand'the consequentdamage to the base material are obviated; as is also the need for trimming the edges of thebase material after application of the transfer and removal of the paper or other temporary carrier.
It is obvious that the foregoing disclosure is'fby way of example only'and thatnumerousfclianges may be made within the purview o'f'the invention. In lieu of employing machine-finished paper, it is possible to use a more expensive paper, although machine-finished paper, even if clay-coated, offers important economic advantages. As has been indicated, the compositions used for the stripping layer and transfer layer may be varied within wide limits. The base material may take any one of the forms previously mentioned or any one of various other conventional forms which usually, but not necessarily, are relatively thick as compared with the thickness of the composite formed as described by applying the transfer to the base material.
It is intended that the patent shall cover, by summarization in the appended claims, whatever features of patentable novelty reside in the invention.
What is claimed is:
1. A transfer process comprising the steps of preparing a transfer by coating paper with an inseparable layer of resinous film-forming material, laying down on such inseparable layer a separable layer of resinous film-forming material that is incompatible with the inseparable layer, and imprinting a decoration on the separable layer; applying the transfer so prepared to a base material having a ground coat thereon, the transfer being so applied to the base material that the decoration on the transfer faces the ground coat on the base material; subjecting the assembly to temperature-pressure conditions conducive to consolidation of the ground coat on the base material and the separable layer on the transfer; and thereafter removing the paper and attached inseparable layer of resinous film-forming ma terial by a dry-stripping operation that leaves on the base material the decoration and the separable layer of resinous film-forming material, the latter forming a covering for the decoration.
2. A process as in claim 1 in which the paper is machine-finished paper.
3. A process as in claim 1 in which the paper has a finishing coat on the side to which the inseparable layer is applied.
4. A process as in claim 1 in which the step of imprinting the decoration on the separable layer i done with an ink compatible with the material of which the separable layer is composed.
5. A process as in claim 1 in which the step of removing the paper and the attached inseparable layer of resinous film-forming material is followed by a step of spraying japrotective coating onto the separable..layer',of --resmous filmforming material] 1 V, l
6. A method of making a dry-stripping transfer comprising, the steps fof applying to, a machine-finished paper a -fi,rst resinous. film-1 'formin'g .material,j v isaid .film. ormin'g. material being. one that adheres ,tenacrously tame paper laying down thereon a secondresinoiis film-. forming material, said s eo unlmj-rormingmaterial being larg'elyiri' mpatjiblewithsaid' first film-forming material and "th reafter. producing a design in said second mm-ror mgmaterial by a separate im nntineL p'erau n.; T i. i
. 7."Af' method. a inclai 16 iriwhich one or the two: filmerormingjmaterms is a vinylfchlm ridefpolymer. 'fj .1
8; A method as'jini claim. 7 in whit: forming material, is a ride and vinyl acetate.
9. A method asi-nclai v m 8 inwhich-the other of the two film-formingfmaterials"}takes the form of a lacquer residue containinga substance selected from the group consisting of the cellulose esters, the cellulose ethers and the polyvinyl acetals.
10 A method as in claim 9- in which the design is imprinted with the aid of an ink containing a resin compatible with the film-forming material in which the design is produced.
11. A transfer comprising a temporary paper carrier, an inseparable layer of resinous filmforming material on the temporary paper carrier, a separable layer of resinous film-forming material laid down on the inseparable layer, and a decorative imprint on the outsideface of the separable layer.
12. A transfer as in claim 11 in which one of the two layers of resinous film-forming material is a vinyl halide polymer.
13. A transfer as in claim 12 in which the filmforming material is a copolymer of vinyl acetate and a vinyl halide.
14. A transfer as in claim 13 in which the other of the two layers of film-forming material is a lacquer residue containing a substance selected from the group consisting of the cellulose esters, the cellulose ethers and the polyvinyl acetals.
15. An article of manufacture comprising a base material; a paper surfacing material overlying the base material, said paper surfacing material having a resinous film-forming material inseparable attached thereto on the side thereof facing the base material; and, intervening between the base material and the paper surfacing material, a composite made up of a layer of. a resinous film-forming material different from the resinous film-forming material attached to the paper surfacing material, an intermediate decorative layer, and a ground coat on the base material, said paper surfacing material and inseparably attached film-forming material being detachable together from the composite and the underlying base material.
16. An article of manufacture as in claim 15 in which the paper surfacing material is a machine-finished paper.
1'7. An article of manufacture as in claim 15 in which the resinous film-forming materials com prising the separably and inseparably attached layers are mutually incompatible 18. An article of manufacture as in claim 15 in. which the base material takes the form of 11 a rigid sheet of substantially greater thickness than the overlying layers. 7
19. A transfer comprising a temporary paper carrier, an inseparable layer of film-forming material on the temporary paper carrier, a separable layer of film-forming material laid down on the inseparable layer, a decorative imprint carried by the separable layers on the side thereof adjoining the exposed face of the transfer, and, on the exposed face of the transfer, a surface layer containing a colorant.
20. A transfer process comprising the steps of continuously feeding a base material from a source to a pressure zone, the base material having a ground coat thereon; continuously feeding to the same pressure zone from a separate source a transfer comprising a temporary carrier, an inseparable layer of resinous film-forming material, a separable layer of resinous film-forming material laid down on the inseparable layer, and a decoration on the separable layer; applying the transfer to the base material in the, pressure zone in such manner as to consolidate the ground coat, the decoration, and the separable 12 layer of resinous film-forming material; drystripping'therefrom the temporary carrier, and the inseparable layer [of resinous film-forming material, meanwhile .collecting the same in compact form; and applying a finishing coat of protective material to the composite on the base material. v
THOMAS S. REESE.
, REFERENCES CITED The following references are of record in the file of this patent:
I UNITED STATES PATENTS Number Name Date 1,797,998 Sadtler Mar. 24, 1931 1,815,444 'Moss July 21, 1931 1,899,066 Tonge Feb. 28, 1933 1,947,516 Broa'dman Feb. 20, 1934 1,981,472 Schneider Nov. 20, 1934 2,258,991 MeNally Oct. 14, 1941 2,275,957 Groif Mar. 10, 1942 2,336,273 Malm Dec. '7, 1943 2,578,150,
,Rathke J; Dec. 11, 1951