US689422A - Art of manufacturing square-bottom paper bags. - Google Patents

Description

No. 689,422. Patented Dec. 24, l00l. C. F. SCHMELZ.

ART OF MANUFACTURING SQUARE BOTTOM PAPER BAGS. (Appliution filed 1m. 19, 1901.) (No Model.) 2 Shuts-Sheet I.

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CHARLES F. SCI-IMELZ, OF HARTFORD, CONNECTICUT, ASSIGNOR TO UNION PAPER BAG MACHINE COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.-

ART OF MANUFACTURING SQUARE-BOTTOM PAPER BAGS.

. SPECIFICATION forming part of Letters Patent No. 689,422, dated December 24, 1901.

Application filed March 19, 1901. Serial No. 51,826. (No model.)

To all whom it may concern:

Be it known that I, CHARLES F. SoHMELz,

a citizen of the United States of America,

and aresident of Hartford, Connecticut, have invented certain new and useful Improvements in the Art of Manufacturing Square- Bottom Paper Bags, of which the following is a specification.

This invention relates to the art, of manufacturing square-bottom paper bags; and it has for its object an improved method of forming the so-called diamond fold in a bellows-sided or tucked tube or blank, such method being adapted for use in connection with any well-known methods of forming the tube and of subsequently pasting and folding the diamond to complete the bag.

My invention has more particularly for its object the improved method of opening out the open or bottom-forming end of the blank,

so as to form the inside triangular folds in an easy and rapid manner, and it comprises as one of its features the manipulation of the plies of the blank between certain points thereof. The several instrumentalities for holding said plies are caused to engage the same at points the distance of whichfrom the bottom-defining line is equal to the depth of the tucks, the blank being opened out by and between these instrumentalities around a primary folding-line which is disposed between said points of engagement and the bottomdefining line, and when said points of engagement have arrived at positions at opposite sides of this primary folding-line the distance between the points of engagement is increased until the sides will have been fully stretched out between said points.

One of the ordinary methods of forming the diamond on a bag-blank comprises the engagement of the upper and lower plies thereof by suitable devices generally known as tuck and box holders, these devices engaging said plies at certain distances from the bottom-defining line, so that when the tucked sides are gradually straightened or stretched out by and between said devices the inside triangular folds will be fully de= veloped. The process of straightening out or stretching the tucked sides is usually carried 'out by swinging the devices which engage one ply of the blank away from those engaging the other ply and substantially around the defining-line as an axis, the distance from each of said devices to the defining-line remaining. substantially uniform throughout this folding operation. In my improved method the plies of the blank are manipulated in such a manner that the tucked sides will have been distended but partially between the points of engagement even after the latter have arrived at positions at opposite sides of the primary folding-line, so that'subsequently the distance between such points must be increased in order fully to stretch out the tucked sides of the tube.

A process incorporating my invention is clearly illustrated in the accompanying draw ings, in which- Figure 1 is a side view of a bag-blank, illustrating the manner in which the upper and lower plies thereof are engaged by the folding instrumentalities. Fig. 2 is a top view of Fig. 1. Fig. 3 is an end View of the blank. Fig. tshows the upper ply of the blank folded over around the primary folding-line. Fig. 5 is a top view thereof. Figs. 6 and 7 show a further advancement in the tube-distending operation; and Figs. 8 and 9 show a side and top View, respectively, of the blank when the folders have arrived at their final positions and the diamond is substantially completed.

In the drawings the blank 10 is shown having tucked or bellows sides 11 and comprising a bag-forming section A and the bottom= formingIsection A, the boundary-line between said sections being generally known as the defining-line and indicated in the present instance by d 01. Referring to Figs. 1 and 2, the upper ply 12 of the blank is shown engaged by the so-called box-holders B and the proper function of which is to fold said ply around the edgefof a member B, which constitutes a folding member cooperative with the box-holders B. The blank 10 is properly positioned relatively to the various folding instrumentalities, so that the member B will be disposed above the upper ply, while the box-holders B and the tuck-holders T will enter the tucks and the cooperative member T will be disposed below the lower ply 13 of the blank, and the front diamond-holder H will engage the same in the manner clearly shown in Fig. 1. In order to insure the proper engagement of the upper ply of the blank by the box-holders B, the member B may now be turned forward in the direction of arrow at and around the edgefuntil the upper ply is firmly clamped between the box-holders B B and said member B, whereupon said member, and with it the box-holders, may be swung back again until the position shown in Figs. 4 and 5 has been reached, in which the primary folding-line is formed by said edge f. At this time the tucked sides have been partially distended between the points 20 and 21, which constitute the engaging points of the box and tuck holders, respectively. The distance between said points will now be increased, passing in its progress the condition shown in Fig. 6, which illustrates ing the distance between the points 20 and 21 somewhat greater than that between the points 20 and 21 of Fig. 4. On a further increase of the distance between said points to the position shown in Fig. 8 the tucked sides will be fully distended or stretched out be tween the points 20 and 21", and the diamond may now be flattened and completed.

From the foregoing it will be seen that while the edge f of the member B serves at first as a member around which the upper ply of the blank is folded over, and to insure both sides of the upper ply being gripped in proper alinement with each other, said edge f will cease to be a folding edge as soon as the dis tance between the box-holders B B and the tuck-holders T T is increased, so that the fold, which finally culminates into the crossfold line of the bag-bottom, is in reality a running fold which progresses at half the speed compared with the increase in distance between the box-holders and tuck-holders. The member T is in this instance the movable member and supports the front diamond: holder H, while the member B remains stationary. It is of course understood that it is immaterial to the proper manipulation of ser es the blank in accordance with my improved method which one of said members is stationary or movable relatively to the other so long as the distance between the tuck-holders and box-holders is increased.

lVhile under ordinary conditions it is not deemed essential that the running fold should be in any way supported, yet in some instances, particularly with a heavier weight of paper, any proper support and guidance for said running fold may be advantageously employed. Furthermore, it is considered that for the purpose of properly carrying out my improved method it is not essential that the member B or the edge fshould extend entirely across the bag-blank, although this construction is preferable in some instances.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The improvement in the art of forming the diamond on bellows-sided tubing, which consists in the engagement of the sides of the upper and lower tube-plies at. points, the distance of which from the primary folding-line is less than the depth of the tucks, folding over one tube-ply substantially around the folding-line as an axis and until the points of engagement are brought to positions at opposite sides of saidline, and subsequently separating said points to distend the tucked sides completely between said points and to develop the inside triangular folds, and subsequently completing the diamond.

2. The improved method of forming adiamond in square-bottom paper bags from bellows-sided tubing, which consists in engaging the upper and lower plies at points, the dis tance of which from the bottom-defining line is equal to the depth of the tucks; completely folding one ply over and on a primary folding-line located between the points of engagement and the bottom-defining line, and subsequently increasing the distance between said points of engagement until the tucked sides have been fully stretched out between said points, and then completing the diamond. Y

CHAS. F. SOHMELZ.

Witnesses:

WM. H. HONISS, NELLIE PHOENIX.

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