US2221197A - Milk bottle cap and method of making the same - Google Patents

Description

H. w. MARTIN 2,221,197

Nov. 12, 1940. .Y

MILK BOTTLE CAP AND METHOD O F MAKING THE SAME Filed May 7, 193e VII '/ i '7 if Patented Nov. 12, 1940 .UNHTED STATE rer orrics lVIILK BOTTLE CAP AND METHOD OF MAKING THE SAME Ware Application May 7, 1936, Serial No. l78,361

9 Claims.

This invention relatesto milk bottle caps of the so-called cover-all type in which the outer face of the pouring lip of the bottle is covered by the cap. A well known cap of this type is disclosed in the Baum Patent No. 1,668,349. This invention has for an object to improve the construction of such a cap, whereby the skirt which encloses the top portionof the bottle is rendered more resistant to flaring under the conditions of use which include subjection of the top portion of the bottle to water and ice and to pressure while subjected to moisture conditions.

In caps of this type, as previously constructed, the skirt has been of non-uniform width throughout, the lower edge being more or less irregular, depending somewhat on the uniformity or lack of uniformity in various directions of the paper of which the caps are formed and on the arrangement of the overlapping layers of the paper. In accordance with the present invention, this skirt is rendered of substantially uniform length throughout and is so treated in the manufacture that it presents a dense horn-like structure more resistant to the entrance of moisture than has been previously the case.

A further object of the present invention is to effect a reinforcement of the cap which materially increases its strength.

A still further object is to provide a construction which, when the caps are stacked, as when they are positioned in the supply reservoir of a bottle feeding and capping machine, prevents any tendency for pressure between the caps to cause aring of their skirt portions and which insures easy feed of the caps one by one from the lower end of the stack, as desired, without the possibility of the caps catching on each other.

A still further object is to improve the general appearance of the cap.

For more complete understanding of this invention, reference may be had to the accompanying drawing in which Figure 1 is a perspective view in section of the main portion of a cap constructed in accordance with this invention.

Figures 2 and 3 are fragmentary sections to a larger scale through different portions of the bottle-lip-enolosing part of the cap.

Figures 4 to 7 inclusive are fragmentary diagrammatic section views showing successive steps in the formation of the main part of the cap.

Figure 8 is a View, partly in side elevation and partly in section of three caps in stacked relation. r

The cap is preferably formed up from paper of the desired thickness which has previously been subjected to treatment such as described in vthe Baum Patent No. 1,668,349 previously mentioned, being preferably moistened and then v5 passed through a bath of hot wax, such as parafn, with the addition of a small amount of hardening wax, such as carnauba or montan wax, after which the paper blanks are allo-wed to stand in closed containers to temper so as to give the l0 moisture time to penetrate through the fibers' and to reduce the paper to a tempered moldable condition. The circular paper blank.| (see Figure 4) is then subjected to a molding operation K as between dies, the paperfirst being engaged 15 over its central disc portion between the die portions 2 and 3. Then the annular die member 6 is caused 'to move into the position' shown in Figure 5, forming the upstanding inner wall 1 of the pouring lip housing of the cap, this die 20 portion 'l cooperating with a mating die member 8 to form the top wallof the pouring liphousing. The marginal portion of the cap blank is then pressed downwardly, as by the annular die member "Las shown in Figure 6, to form a depending skirt lZ which projects downwardly some distance below the inner wall 1 and in substantially parallel relation thereto and concentric therewith. The die members, particularly those which form the skirt portion, subject the treated ypaper stock to heavy pressure such as to produce the translucent horn-like structure described in the Baum patent, to which reference has heretofore been made. The process of forming the cap previous to this invention has been allowed.l to stop here, as described in the Baum patent, and `thel lower edge' of the skirt portion l2 has alwaysbeen more or less irregular.

In accordance with the present invention, this lack of uniformity is overcome by applying pressure against the edge of this skirt, compacting vand more closely interfelting the material thereof, and condensing this edge so that italso is formed into a dense horn-like surface structure. As shown, this is done `by the annular die'member i3 which moves between the-members 8 and Ill and narrows the'skirt from the width shown in Figure 6 to that shown'in Figure 7. This narrowing of the skirt is produced while it is supported on opposite faces yby the die portions 6 and it Which produce heavy pressure thereon and prevent increase in thickness of the skirt which remains throughout the process substantially that of the single layer of the paper blank. The endwise pressure thus acts on the free edge positioned opposite to the ribs M.

of the skirt which is the free edge of the blank. This is supported against folding up or bending while the edge pressure is exerted, so that this edge is reduced to the desired horn-like structure, surface sealed against the entrance of moisture. Where this edge compacting is not employed, the relatively rough edge of the skirt has been less able to resist the entrance of moisture into the material of the cap and the entrance of such moisture promotes flaring of the cap skirt later on, permitting it to spring away somewhat from the bottle and impairing the holding ability of the cap thereon. While the treatment of the side walls of the skirt portion between the dies under heavy pressure has been found very effective to prevent flaring, this further cornpacting of the edge of the skirt further increases the ability of the cap to withstand daring under the severe conditions of icing and pressure to which these caps are subjected in service.

Besides condensing this end edge and bringing it into a common plane, advantage may be taken of this pressure, in accordance with the present invention, for producing further desirable improvements in the cap structure. Thus the die member 8 may be provided with substantially radially arranged depressions in its lower face so that the endwise pressure of the skirt portions causes the paper stock to be driven up into these depressions, producing radial reinforcing ribs of solid cross-section across the top wall of the pouring lip housing, as shown at I4 in Figure l. The upperface of the die member 6 is preferably plain so as to form the lower face of the upper wall of this housing without depressions These ribs, being of solid cross section, are of materially greater strength than those shown in the. Baum patent and previous constructions wherein the ribs are merely corrugations inthe cap material so that the lower face of the upper wall of the housing has depressions positioned opposite to each of the ribs on the top face. Figure 2 shows a section taken through the pouring lip housing between the stiffening ribs while Figure 3 is a similar View showing a section taken through one of the ribs.

A further improvement which materially strengthens the cap may also be produced by providing the upper face of the die member 6 with an annular depression or groove, as at I5, adjacent to its outer edge so that, when the paper stool-z is condensed by edgewise pressure exerted on the skirt, this depression is filled forming a thickened annular reinforcing for the cap adjacent to the outer or skirt wall portion I2.

It is likewise preferable to provide an annular channel around the top edge of the skirt portion and, as shown, this is provided within the die member l0, as at 2i). This grooved portion is also filled with the paper stock by the molding pressure exerted on the lower end of the skirt, thus forming an annular upstanding rib 2! about the outer margin of the pouring lip housing as an upward extension of the skirt i2 above the top of the pouring lip housing. The top of this rib or marginal bead is at least as high as adjacent portions of the radial ribs i4 which terminate at the inner face thereof so that the outer ends of the radial ribs are not engaged by the superposed cap in the stack. Preferably, the dies are so formed and the size of the blank is so proportioned that in the final molded condition of the cap skirt shown in Figure 7 the outer edge of the skirt i2 is brought to such a position that when the caps are stacked the engagement between them is at least mainly in alinement with the inner wall 1, thus relieving the outer wall of the skirt from any substantial wedging pressure tending to cause spreading. Thus, when the caps are stacked, as shown in Figure 8, it is an easy matter to feed out the lowest cap of the stack, there being little, if any, tendency for the cap thereabove to catch thereon and offer obstruction to such free removal.

Besides greatly improving the cap from the standpoint of ease of handling and effectiveness in resisting the stresses of use, this treatment substantially improves the appearance of the cap, particularly where the outer parts of the stock of which the cap is made are colored. This treatment deepens the color at the lower edge of the skirt and adds greatly to the ornamental appearance of the cap, both when it is on the bottle and when it is associated with other caps in a stack, as received from the manufacturer for application to a bottle filling and-capping machine.

After the formation of the caps, as hereinbefore described, they may be provided with reinforcing disks, such as are shown at 25 in Figure 6, as is well known in the art, such disks serving to reinforce and stiifen the central depressed portion of the caps which enter into the mouths of the bottles.

From the foregoing description of the cap and a method of making the same, it should be evident to those skilled in the art that various changes and modifications may be made without f departing from the spirit or scope of this invention as dened by the appended claims.

I claim:

1. A milk bottle cap having a depressed central portion to enter the mouth of a bottle and an annular pouring lip housing of generally channel shape in cross-section outwardly of said central portion, said housing having inner and outer substantially parallel walls and a top wall bridging said parallel walls, said top wall having thickened substantially radially arranged ribs on its upper face, the lower face of said top wall being substantially devoid of depressions opposite the said ribs, said top wall being substantially thicker adjacent to its said outer wall than adjacent to said inner wall and presenting an upstanding marginal bead on its upper face outwardly of said ribs adapted to register with the lower edge of the outer wall of a superimposed cap in a stack.

2. A rigid molded paper article formed up from a blank of waxed paper, said article having a central disc portion and a marginal portion of generally inverted U-shape cross section extending upwardly therefrom to form an inner vertical flange and an outer depending skirt having a bottom free edge formed by the free edge of the blank, said skirt comprising folded layers of said paper, interfelted and compressed transversely to a dense water-resistant horn-like condition throughout the length thereof and being of a thickness corresponding to a single layer of said blank, said free edge being interfelted and compressed axially to a dense water-resistant horn-like surface capable of resisting penetration of moisture into the fibers from the exposed edge thereof and forming a substantially straight edge devoid of irregularities which would interfere with the feeding of the individual articles from a stack thereof.

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3. A rigid molded paper article formedv up from a blank of waxed paper, said article having a central disc portion and a marginal portion of generally inverted U-shape cross section extend- 5- ing upwardly therefrom to form an inner vertical flange, a top portion and an outer depending skirt, said skirt comprising folded layers of saidl paper interfelted and compressed trans- I versely to a dense water-resistant horn-like condition throughout the length thereof, the free edge of said skirt being interfelted and compressed axially to a dense water-resistant hornlike surface capable of resisting penetration of `moisture into the fibers from the exposed edge thereof and forming a substantially smooth, straight bottom edge and a raised marginal bead molded on said top portion in alinement with and forming an upward continuation of said skirt, said bead having a smooth top surface adapted to engage and support the skirt of a similar article stacked thereon, the smooth bottom edge of said skirt and the smooth top surface of said bead cooperating to permit feeding of the individual articles from a stack without injury to or deformation of the respective skirts.

4. A rigid milk bottle cap formed up from a blank of waxed paper, said cap having a central bore closing portion and pouring lip housing substantially U-shape in cross section with an inner vertical flange and an outer depending skirt having an outer free edge formed by the free edge of the blank, said skirt comprising folded layers of said paper, interfelted and compressed transversely to a dense water-resistant horn-like condition throughout the length thereof and being of a thickness corresponding to a single layer of said blank, said free edge being interfelted and compressed axially to a dense water-resistant horn-like surface capable of resisting penetration of moisture into the bers from the exposed edge thereof and forming a substantially straight edge devoid of irregularities which would interfere with the feeding of the individual articles from a stack thereof.

5. A rigid milk bottle cap formed up from a blank of waxed paper, said cap having a central bore closing portion and pouring lip housing substantially U-shape in cross section with an inner vertical flange, a top portion and an outer depending skirt, said skirt comprising folded layers of said paper interfelted and compressed transversely to a dense water-resistant horn-like condition throughout the length thereof, the free edge of said skirt being interfelted and compressed axially to a dense water-resistant hornlike surface capable of resisting penetration of moisture into the fibers from the exposed edge thereof and forming a substantially smooth, straight edge, and a raised marginal bead molded on said top portion in alinement with and forming an upward continuation of said skirt, said bead having a smooth top surface adapted to engage and support the skirt of a similar article stacked thereon, the smooth bottom edge of said skirt and the smooth top surface of said bead cooperating to permit feeding of the individual articles from a stack without injury to or deformation of the respective skirts.

6. A rigid milk bottle cap formed up from a blank of waxed paper, said cap having a central bore closing portion and a pouring lip housing substantially U-shape in cross section with an inner vertical flange, a top portion and an outer depending skirt, said skirt comprising folded layers of said paper interfelted and compressed transversely to a dense water-resistant horn-like condition throughout the length thereof, the freev edge of said skirt being interfelted and compressed axially to a dense Water-resistant hornlike surface capable of -resisting penetration of 5 moisture into the fibers from the exposed edge thereof and forming a substantially smooth, straight edge, raised transverse ribs thicker than the paper of said blank molded on said top portion and a raised marginal beadvmolded on said 10 top portion in alinement -with and forming an upward continuation of said skirt, said bead having a smooth top surface adapted to engage and support the skirt of a similar article stacked thereon, the smooth bottom edge of said skirt 15 and the smooth top surface of said bead cooperating to permit feeding of the individual articles from a stack without injury to or deformation of the respective skirts.

7. The method of making a rigid molded paper 20 article from a blank of waxed paper which comprises die-forming said article into the shape of a central disc portion and a marginal portion of generally inverted U-shaped cross section extending upwardly therefrom to form an inner 25 vertical flange and an outer depending skirt having folded layers of said paper and having'a bottom free edge formed by the free edge of the blank, subjecting said skirt to a pressure sufficient to interfelt and compact the folded layers 30 into a substantially homogeneousl rigid horn-like structure of substantially uniform thickness corresponding generally to the thickness of a single layer of said blank and, while said skirt is held under transverse pressure, applying axial pres- 35 sure to the free edge thereof sufficient to interfelt and compact the free edge into a dense water-resistant horn-like condition, whereby said free edge becomes capable of resisting penetration of moisture into the fibers from the ex- 40 posed surface thereof.

8. The method of making a rigid molded paper article from a blank of waxed paper which cornprises die-forming said article into the shape of a central disc portion and a marginal portion 45 of generally inverted U-shaped cross section extending upwardly therefrom to form an inner vertical flange, a top portion andan outer depending skirt having folded layers of said paper, subjecting said skirt' to a pressure sucient to 550 interfelt and compact the folded layers into a substantially homogeneous rigid horn-like structure of substantially uniform thickness, and while said skirt is held under transverse pressure, applying axial pressure to the free edge thereof sufficient to interfelt and compact the free edge into a dense Water-resistant horn-like condition, whereby said free edge becomes capable of resisting penetration of moisture-into the fibers from the exposed surface thereof, and uti- 60 lizing said axial pressure to cause the bers of said skirt to ilow upwardly and form a raised annular bead on said top portion in alinement with said skirt, the upper surface. of said bead. and bottom edge of said skirt being caused to 65 have substantially straight surfaces adapted to facilitate the feeding of the individual articles from a stack thereof without causing injury to or deformation of the respective skirts.

9. The method of making a rigid molded paper 70 article from a blank of waxed paper which comprises die-forming said article into the shape of a central disc portion and a marginal portion of generally inverted `Ushaped cross section extending upwardly therefrom to form an inner `1li lizing said axial pressure on said skirt to cause the bers to flow upwardly to form a raised marginal bead on said top portion in alinement with said skirt and to form on said top portion raised transverse ribs substantially thicker than the paper of said blank, said skirt and bead being compact axially to form substantially straight upper and lower surfaces adapted to facilitate the feeding of the individual articles from a stack thereof without causing destruction or injury to 10 the respective skirts.

HAROLD W. MARTIN.

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