US1974098A - Manufacture of window envelopes - Google Patents

Description

Sept. 18, 1934. P. BECKER ET AL v MANUFACTURE OF WINDOW ENVELOPES Filed March 6, 1951 lllllllll LL W Patented Sept. 18, 1934 UNITED STATES PATENT OFFICE 1,974,098 MANUFACTURE or wmnow ENVELOPES Maine Application March 6, 1931, Serial No. 520,68

lin Germany March 10, 1930 2 Claims. (CI. 3412) The present invention relates to the manufacture of window envelopes of the one piece type, that is, envelopes in which anintegral portion of the face of each envelope blank 5 is rendered wholly or substantially transparent by treatment with a suitable penetrating varnish or similar substance.

Heretofore, in the manufacture of one piece window envelopes, the envelope blanks after receiving the imprint of varnish, have been subjected to a period of heating at high temperature for the purpose of rendering the transparentizing solution thinner and promoting its penetration into the paper. It has been found, however, that when the relatively high heat is maintained long enough to insure thorough impregnation of the window portions by the varnish and complete dryingthereof, detrimental effects on the texture of the paper and fading of the color of the same have resulted.

According to the present invention, the above mentioned disadvantages previously associated with the manufacture of window envelopes are eliminated by successively passing the treated blanks through a series of heated chambers, in each of which the temperature is adapted to be separately controlled. This improved arrangement permits envelope blanks made from different grades of paper to be subjected successively to desirable and readily varied heat changes, to obtain complete impregnation of the envelope material by the varnish and complete drying, without ever subjecting the blanks to the, detrimental effects of excessively high temperatures. The invention further provides an easily operated mechanism of large capacity through which envelope blanks may be passed rapidly, thereby obtaining a high rate of production of completed blanks. v 40 r The above and other advantageous features will more fully appear from the following de-' scription taken in connection with the accompanying drawing, in whieh:-

' Fig. 1 is a view in side elevation of a machine embodying the invention.

Fig. 2 is a fragmentary view illustrating the mechanism for delivering finished blanks, the

parts of Fig. 2 being adapted to cooperate with;

the left hand end of the machine shown in Fig. 1.

Like reference characters refer to like parts in the diiferent figures.

The apparatus of the present invention is arranged to operate on treated envelope blanks as successively presented by a suitable window printing and varnishing machine 1 and comprises a heating and drying device 2 through which the treated blanks travel on a conveyor system, the continuous operation of which finally carries the blanks to delivery mechanism 3, adjacent the varnishing machine 1. The individual blanks are printed and varnished by any suitable mechanism in the machine 1, as for example, by a mechanism of the type shown in United States Patent No. 1,540,295 issued to Swift June 2, 1925, in which an ink border is printed on the outer face of each envelope blank and subsequently the impregnating and transparentizing fluid is applied to its inner face. As the treated blanks emerge from the varnishing machine 1, a belt 4 delivers them to a transfer belt 5 which conveys the blanks into the heating and drying device 2, next to be described.

The heating and drying device 2, according to the invention, comprises an enclosure 6, the major portion of which is divided into a plurality of separate chambers 7, 8 and 9 by partitions 10 and 11 of heat insulating material. Each of the chambers '7, 8 and 9 is separately heated and the temperature thereof'is adapted to be separately controlled in any convenient manner, as for example, by heating elements of any suitable typ such as variable resistance electrical heating coils 12. The blanks are conveyed through these chambers, successively, by-

acontinuous conveyor system comprising, in

, rollers 16 and 17, which latter may be provided with cogs, not shown, to mesh with links in the chains.

Treated blanks are delivered by the conveyor belt 5 to fingers 15 on the upwardly moving side of the chain 13 of the first chamber 7 and are carried upwardly thereby into the heated upper portion of the chamber '7 and then down- 105 wardly to connecting transfer belts 18 and 19 by which the blanks are removed from the chain 13 of chamber '7 and delivered to the chain 13' of chamber 8. The blanks, are then carried upwardly in a similar manner into the n heated portion of the second chamber 8 and then downwardly to transfer belts 20 and 21, which serve to deliver the blanks to the endless .chain 13" of the third chamber 9. After passvails the belt 23 being supported by idler rolls 25, as it conveys the blanks beyond the main enclosure 6, and beneath the varnishing machine 1 to the delivery mechanism 3, which as shown in Fig. 2 serves to pile the blanks in any suitable manner'for removal. While the blanksare being carried on this belt 23, beneath the heating chambers, the residue from the varnish, or other transparentizing fluid, is further dried by the comparatively low heat, and is allowed to cool enough so that it is solidified before it reaches the delivery mechanism 3. Consequently, successively delivered blanks may be stacked without sticking together.

The various chambers of the drying device 2 may be heated to any desired temperatures to accomplish the desired impregnation and drying. For example, in treating blanks of light weight paper, the temperature of the chamber 7 through which the blanks are first carried may be about.

45 centigrade, to thin the transparentizing material and permit the paper to be impregnated without appreciable drying; in the second chamber 8 a somewhat higher temperature, for example, 60 C., may prevail which causes the transparentizing material to become still thin-t ner and thoroughly soak and penetrate the paper; in the last chamber 9 a somewhat higher temperature, for example C., may prevail, in the absence of moisture, to obtain rapid drying of the material. If desired, ventilating devices may be provided in the various chambers to carrythe fumes away and eflfect quicker drying. The temperature variations noted above are suggestive only of one method of treatment, and obviously difierent ranges of temperatures may be employed for different grades of papers.

The. invention may be further adapted for intermittent heating and cooling of' the blanks, as any chamber may be maintained at a temperature lower than the adjacent chambers. Be-

cause of the transfer'from one chamber to another in a zone below the several heat sources, it will be apparent that the blanks are permitted to cool somewhat while passing between successive chambers and that in travelling on the belt 23, the finished blanks will be thoroughly dried before stacking.

It will be apparent that, due to the great length of conveyor system by which the blanks are carried up and down through the several drying chambers, the device will handle at one time a much greater number of envelopes than a single chamber drier, and willfurthermore permit the blanks to be passed through the drier at a greater speed than in the single chamber. Since the blanks remain at the top of each chamber only a very brief time, they are not subjected 'to the high temperatures prevailing there for a long enough time to soften the varnish and cause its spreading on the blanks, outside the window areas.

We claim: H i 1. In apparatus for treating envelope blanks, a heating and drying device comprising a plurality of vertical chambers, a vertically arranged endless conveyor chain in each of said chambers for conveying the blanks upwardly and downwardly in each of said chambers, individually operated transfer mechanisms for conveying the blanks from one conveyor chain to another at the lower portions of said chambers and adjacent the lower portions of the conveyor chains, and means for controlling the temperature in each of the chambers individually.

2. In apparatus for treating envelope blanks, a heating and drying device comprising a plurality of vertical chambers, a vertically arranged endless conveyor chain in each of said chambers for conveying the blanks upwardly and downwardly in each of said chambers, individu-, ally operated transfer mechanisms for conveying the blanks from each of said conveyor chains to the successive conveyor chain in an adjacent chamber, said transfer mechanisms operating to transfer the blanks at points adjacent the lower portions of the chambers and adjacent the lower portions of the conveyor chains, and means for controlling the temperature in each of the chambers individually.

PETER BECKER. FRITZ POPPENBURGER.

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