US1915164A - Method of forming paper receptacles - Google Patents

Description

June 20, 1933. w QREM r AL 1,915,164

METHOD OF FORMING PAPER RECEPTACLES Filed Oct. 10, 1931 m IE.

W H. O-r m and H. f/(m'esche.

Patented June 20, 1933 "UNITED STATES PATENT OFFICE WILLIAM H. OREM AND HARRY F. KNIESCHE, F BALTIMORE, MARYLAND METHOD OF FORMING PAPER RECEPTAGLES Application filed October 10, 1981. Serial No. 568,190.

1 od hereinafter described.

Another object is to provide a methodwhich is capable of being effected by a single stroke of a suitably designed machine, the several steps of the method being included .in such single stroke.

Another object is to provide for making an ornamental and useful form of receptacle by certain steps of the method, and for making another form of receptacle by an added 9 step of the method, such second form having a steeper and more rigid wall than that of I the first-mentioned receptacle.

Other objects and important features are pointed out or implied in the following details of description, in connection with the accompanying drawing in which:

Figure 1 is a vertical sectional view through a part of a machine by which the paper receptacle may be formed, each by a single stroke of the machine;

Figure 2 is a greatly enlarged sectional view illustrating how the margin of the pa- 7 per sheet is gathered into exact and regur larly spaced corrugations in the first step of forming the wall of the receptacle;

Figure 3 is a greatly enlarged View showing the corrugations expanded by their inherent resilience in forming a receptacle such as shown in Figure 7 s Figure 4 is a view illustrating a greatly enlarged wall section at a stage approaching the finished stage of a receptacle such as shown in Figures 5 and 6;

Figure 5 is av central sectional view of a finished paper receptacle, the section being taken along the line 5-5 of Figure 6;

Figure 6 is a top plan view of the receptacle illustrated in Figure 5; and

Figure .7 is a plan view of a receptacle formed by this method.

In efli'ecting this method, any appropriate means may be employed, and the means here illustrated will now be described in order that the method may be more fully understood, as follows:

A primary forming die 1 is provided with an opening 2 and with inwardly converging ribs or ridges 3 which extend to the margin of the opening 2 and thence extend parallel to one another intothe opening2, as indicated at 3. A guiding and tensioning plate 4 isprovided with an opening 5 and with inwardly converging guiding and tensioning ribs or ridges 6 arranged in alternate relation with the ribs 3, so that when the plate 4 is pressed down upon a paper sheet of proper size and shape when it is properly positioned on the ribs 3, the marginal part of the paper sheet will be frictionally clamped for, the purpose of tensioning the paper and guiding it into grooves between ribs 3a. The

pressing die 7 is formed with peripheral ribs 8 which engage with the marginal parts of the paper sheet which are tensioned by the ribs 3 and 6, so as to effectively force these parts of the paper sheet through the opening 2.

At this juncture, it should be understood that any appropriate kind-0f fibrous sheet may be employed for making the receptacles, and such .fibrous sheet may be preferably formed of a number of thin sheets laminated so as to form a relatively thick sheet which may be coated with paraflin or other appropriate material, or may be saturated with any appropriate water-proofing material. Therefore, the term paper sheet is employed as a convenient and broad term which should be construed to mean any appropriate fibrous sheet from which may be formed receptacles of the kind here illustrated and of various other kinds of this general class'of dishes or dish-likereceptacles. In forming such receptacles, it is necessary, for various'reasons, that the wall be upwardly and outwardly inclined, rather than vertical, one reason being that such receptacles automatically free themselves from thepressing die, in contradistinction to a receptacle having a vertical wall which would remain engaged with the ribs 8 and prevent removal of the receptacle from the pressing die. The most important reason is that in ironing the finished article at some oblique angle of the sides, the fibers will cease to interlapand'interlock, and folds would take place in the sheet itself if the angle of the sides were more nearly vertical.

These folds in the sheet would be contrary.

to our method and would result in a broken or faulty place or places in the side of the tray. This emphasizes the absolute neces sity of having the sides of the receptacle oblique rather than vertical. For thus forming the inclined wall, it is essential that the fibers of the sheet be somewhat resilient, so it should be understood that such resilient fiber sheets are employed in carrying out this method.

Another reason that the wall must be inclined, instead of vertical, is that the corrugations must not overlap one another sulficiently to defeat the main feature of this method, viz., the gathering and flufiing of the fibers so they interlap and interengaged with one another within the sheet.

A secondary die plate 9 may be united with the plate 1 by the means illustrated Or by any appropriate means, or it may be eliminated when forming receptacles such as shown in Figure 7. Whenthe plate 9 is not used, the corrugations of Figure immediately expand from the form shown in Figure 2 to that of Figure 3 so that the wall is corrugated as shown in Figures 3 and 7, but such wall is inclined, rather than vertical, because of the expansion of the corrugations. After the initial step which consists in tensioning the margin of the paper sheet, and during the next step which consists in pressing the sheet through the opening 2 while the ribs 3, and

6 are still engaged with the paper sheet, the

margin is drawn toward and into the opening 2, over the curved upper edge thereof, thereby not only curving the marginal part for producing the final curvature of the re ceptacle as indicated at 10 of Figure 5, but also reducing the marginal extent of the paper sheet while laterally expanding and parts of the corrugations as indicated at 11. This flufling of the corrugations consists in causing parts of the fibers to separate. While some of the fibers are interlapped, others are merely bent, so that when pressure is released, the bent fibers tend to straighten or resume their initial status, thus causing-said expansion from the form shown in Figure 2 to that of Figure 3. In this latter form, the parts 11 remain thickened or laterally expanded because of the inter-lapping of thefibers in consequence of the gathering which is effected by theribs 3.

In forming the more compact wall such as shown in Figures 5 and 6, the fibers of parts tacle, so that such segmental parts are thic ened, as indicated at 15, while the intermediate or alternate parts of the receptacle remain the same thickness as the original sheet or blank from which these receptacles are formed. 1 y

This invention is applicable "to various forms of paper receptacles which have flared or upwardly inclined walls, whether the receptacles are substantially rectangular, as

shown, or circular, or of any other appropriate shape.

It is desired to emphasize the fact that the combination of dies shown in Figure 1 is shown merely to illustrate one of the various combinations of means for ca g out this method, and that the invention 1s not limited to this specific means.

What we claim as our invention is:

1. The method of forming an inclinedwalled tray from a fibrous sheet, consisting in pressing alternate very narrow sections of the sheets margin in opposite directions by forcing said narrow sections between corrugating ribs and thereby forming corrugations having fluifed fibers therein, and thereafter applying resistance at one side of the corrugations while exerting pressure against the other side of the corrugations with suflicient force to cause the flu'lied fibers to interlap within the sheet and to become so compact that the corrugations are converted into substantially. smooth thickened parts of the inclined wall.

2. The method of formingan inclinedwalled tray from a 'fibrous laminated sheet,

at the oposite side of the corrugations and in the direction of the resistance for causing an interlnpping of the lamina, the

parts of the wall, and thereafter applying heavy pressure on the corrugations in the proper manner and with suficient force for converting the flufi'd or spaed lamina of the corrugations into the sand compact thlckened parts.

In testi tures.

mony whereof v ve aflix our signa- WILLIAM H. 01mm. HARRY F. KNIESCHE.

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