Device For The Manufacture Of Paper Cups

Abstract

A device in which a conic-shaped mantle and a cup-shaped bottom portion are assembled on a conic-shaped pin by a mantle seam sealing operation, and a placement of the bottom portion within the narrower end of the mantle, projecting beyond the pin, in flanged interlocking relationship. In the sealing operation a movable member is associated with the pin to be extensible along the seam line of the mantle which is received over the pin and has a portion extending beyond the pin, so as to provide an abutment surface at this portion against which a pressing member urges the mantle at the seam line. After this movable member is retracted another member places the bottom portion in position in the mantle and a still further member urges the bottom portion and mantle into interlocking relationship.

Description

The invention concerns a device for the manufacture of cups made of paper or similar material and consisting of a conic mantle and a bottom portion or part, which is inserted in this mantle with its edges pointing toward the narrower end of the mantle. As thus inserted the outer surface of these edges rests against the inner surface of the wall of the mantle.

Since the bottom surface of the bottom part is situated at a certain distance from the mantle, it must have an exterior diameter greater than the interior diameter of the narrower end of the mantle if its edge is to rest against the inner surface of the mantle. In connecting the two parts, the bottom part has, therefore, so far been introduced from the wider end of the mantle. With a first, already known device, the cut mantle is rolled around a pin, which must be at least as long as the mantle if it is to form an abutment for bracing the entire mantle seam against a pressing cheek.

Along this seam, the mantle overlap, which is provided with a layer of glue or a thermoplastic sealing film, is sealed or glued together by the use of a pressing cheek, applying heat if necessary, until the connection is tight. Thereafter, the mantle removed to another pin on whose front the cup bottom has been placed previously. This new pin is shorter at its narrower end than the first pin in order to allow space for the bottom in the mantle.

The above described device provides on the one hand, the advantage of an even seal of the mantle seam along its entire length, but, on the other hand, it has the inconvenience of requiring the use of two series of supporter pins for the mantle, which, in turn, require normally two revolving tables for each series of pins.

A second known device avoids the double pin series by rolling and sealing the mantle on a pin after having placed the cup bottom on the front or in a recess of the front of the pin. In this case, the pin must be shorter than the cup, as the part of the case which is to receive the cup bottom, must be free of the pin. Therefore, the pin acts as abutment against the pressing cheek for only part of the total length of the mantle seam. Therefore for the time being, the seam can be sealed only from the open cup border to near the bottom. The remaining part of the mantle seam near the bottom will be glued or sealed, once the bottom is joined to the mantle. When the bottom edges are pressed on to the mantle, the still open part of the mantle is sealed simultaneously. Since this is carried out in two different work positions and since there are varying numbers of paper layers in the two areas to be sealed there frequently are badly sealed or unsealed parts of the joint near the bottom surface of the bottom part, i.e. in the front of the pin.

The object of the invention is, therefore, to provide a device of the above-mentioned kind, that avoids the necessity of two pin series as well as insuring a complete and total sealing of the mantle seam. The solution according to the invention consists in a device with the following characteristics:

a. The device has an arrangement for the sealing of the seam of the mantle part comprising a conic pin to hold the mantle part, a pressing cheek which presses the mantle seam from outside against the pin and a movable abutment in the pin on the other side of the mantle seam having a surface parallel to the surface of the pin. Both the pressing cheek and the abutment cover the total length of the mantle seam.

b. The device includes an arrangement for the insertion of the bottom in the mantle, including a conic pin to hold the mantle, which on its narrower end, according to the height of the bottom, shorter than the mantle, and a part for the insertion of the bottom into the mantle.

c. The same pin which is used to hold the mantle, is also used in the device to seal the seam and to insert the bottom.

d. The abutment comprises a movable part which, in the seam sealing device acts to extend the pin surface at the narrower end of the pin and which can be removed when the bottom is inserted and/or worked on.

Since the abutment in the device for the sealing of the mantle seam extends over the entire length of the seam, the seam can be sealed completely, even near the bottom surface. On the other hand, the pin leaves enough space at the narrower end of the mantle for the later insertion of the bottom portion and work on it. It is not necessary to transfer the mantle from a longer to a shorter pin. Work on the bottom includes all operations such as pressing of the bottom edges with the mantle edges or the flanging of the mantle edge around the bottom edge.

An advantageous form of the movable abutment consists of a strip that can be moved in a groove of the pin along its mantle line. During the operation of mantle formation it is pushed beyond the narrow end of the pin so as to have the total length of the seam supported by the strip. Subsequently prior to the insertion of the bottom, the strip is drawn back to have its front edge coincide exactly with that of the pin.

Another advantageous possibility is to mount a movable part of the abutment on the front of the pin from its free side, the front side of the pin and the nearer side of the movable part being fitted with interacting grooves which insure the required support of the movable part.

The invention is described in detail below, with reference to the drawings:

FIG. 1 shows a longitudinal section through a pin with a movable strip serving as an abutment;

FIG. 2 is a top plan view of the pin, according to FIG. 1;

FIG. 3 shows a longitudinal section through a pin with a movable abutment part that can be mounted from the outside;

FIG. 4 shows the end of a pin with mounted mantle and an inserted bottom portion and

FIG. 5 shows a partial section through a bottom edge of the pin and adjoining parts during widening of the bottom portion in the mantle.

FIG. 1 represents a pin 1 of conic form, fixed on, e.g. a revolving table above a shaft which is centrically designed on its thicker end. The machine has a number of such pins which progress through the various points of operation. The front part 3 of the pin is flat and perpendicular to its medial axis.

Along a line of the mantle, there is a groove 4 in the outer surface of the pin into which a strip 5 is fitted. This strip can move along the length of the groove and the outer surface of the strip conforms to the conic form of the pin. The strip must be able to slide at least between a first terminal position in which its front surface 6, parallel to front surface 3, coincides with front surface 3 (dashed line in FIG. 1) and a second terminal position in which front surface 6 extends beyond front surface 3 of the pin to allow sealing of the mantle seam along the desired length. To guide the strip, it is fitted with a roller 10 which acts with appropriate guidance devices, such as guide rollers, which have not been included in the drawing. The guidance device is synchronized to arrange for the strip to be pushed beyond front surface 3 during the phase of the operation when the mantle seam is sealed and to remain in the pin when the bottom is fixed to the mantle. The mantle to be formed and sealed on pin 1 is indicated as 7 in FIG. 1. Above strip 5, the mantle seam 8 can be recognized by the double layer of material. The strip represents the abutment for pressing cheek 11.

Another abutment is shown in FIG. 3. Those parts that have already been explained in FIG. 1 have the same numbers. Pressing cheek 11 is shown above mantle seam 8. On the other side, the seam is supported partly by pin 1 itself, partly by a supporting part 12. This supporting part consists of a guiding shaft 13 which can be moved axially on a guiding pivot not shown, and of a shoe 15 provided with a centering extension 16 which sits in a centered recess 17 arranged in the middle of the front part of pin 1. Both centering extension 16 and centering recess 17 are conic. Moreover, the shoe 15 has an arched side part 18, which during the phase shown when the shoe sits on front part 3 of the pin 1, corresponds to the conic form of the pin and rests against the inner surface of seam 8 to back it against cheek 11. Guiding parts 13 and 14 are inclined compared to the longitudinal axis of pin 1 to allow the unimpeded movement of the shoe 15 through the protruding edge 19 of the mantle into this edge. After seam 8 has been sealed in its entire length through this pressing operation, support part 12 can then be removed. The pin 1 supporting the sealed mantle progresses, after sealing of the seam, to another point in the machine, where bottom 20, comprising bottom surface 21 and edges 22, is introduced by part 20a (FIG. 4). The present example supposes that the bottom portion, having been preformed with a diameter smaller than the end of the mantle, is introduced through the narrow open end 23 of the mantle. As indicated above, the bottom could also be brought into the desired position within the mantle by other means, for instance by pushing it into an empty space that reaches from the front side of the short pin toward its thicker end, before sealing the mantle, as explained in U.S. Pat. No. 3,157,339. In such a case, the movable strip 6 cannot be used, but the device according to the invention, with support 17 can be used.

After insertion of the bottom, the mantle edge is flanged in a manner seen in FIG. 5, using a flanger 24 parallel to pin 1 and moving axially to the latter. This instrument bends the protruding edge 19 of the mantle 7 inwards while an axial force is exerted on the free front surface of the edge whose original position in FIG. 5 is indicated by a dotted line. This operation pushes the edge downwards which causes the edges near the bottom border 25 to change form and merge into the level of the bottom surface. Border 25 is, correspondingly, rolled outward until it touches the inner surface of mantle 7 as demonstrated by the full line in FIG. 5. Afterwards, the edges may be sealed to the mantle.

Claims

What is claimed is:

1. In a device for the manfacture of cups of paper or similar material, the cups consisting of a conic-shaped mantle and with a cup-shaped bottom portion inserted into the mantle with the side edges pointing toward the narrower end of the mantle and with the outer surface of the bottom portion being joined to the inner surface of the mantle, the improvement which comprises:

a. a conic-shaped pin adapted to receive a conic-shaped mantle in overlying relationship thereon, said mantle, when so received, partially extending beyond said pin at the narrower face thereof, said mantle having a seam portion extending along the length thereof:

b. a pressing cheek movably disposed adjacent said conic shaped pin and opposite said seam portion of said mantle;

c. means movably disposed to be moved adjacent the seam portion at the edge extending beyond said pin and within said mantle opposite said pressing cheek, whereby said seam portion is supported by an abutment surface, in relationship to said pressing cheek, along said pin and along said means.

2. A device as defined in claim 1 wherein said means is a strip disposed in a groove in said pin at the peripheral surface thereof, said strip having a surface conforming to the surface of said pin, and said strip being movable between a position in which it is completely confined within said pin and a position wherein a portion thereof extends beyond the narrower end of said mantle.

3. A device as defined in claim 1, wherein said means is disposed adjacent the narrower end of said pin and is adapted to be moved into contact therewith, said means having a shoe thereon which, when said means contacts said pin, extends along the seam line above said narrower end of said pin and provide an abutment surface, in conjunction with the surface of said conic-shaped pin, against which the seal line can be pressed by said pressing cheek.

4. A device as defined in claim 1, further comprising second means disposed adjacent the narrower end of said pin and movable axially of said pin to deposit a bottom portion of the cup upon the narrower face thereof when said means are displaced from abuting relationship with the seam line above said narrower face, said bottom portion, when said deposited, having the bottom wall in contact with said narrower face and said side edges extending adjacent to the inner surface of said mantle.

5. A device as defined in claim 4 further comprising a third means movable axially of said pin and toward said portion of said mantle extending beyond said narrower face and said side edges of said cup-shaped bottom portion, said third means being adapted to move, after said second means is retracted from within said mantle, against said portion of said mantle and said side edges of said cup-shaped bottom portion extending beyond said narrower surface of said pin to urge said portion and said side edges into a flanged interlocking position.