JPH0646668Y2 - Bottom container folding device for paper containers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention generally relates to a bottom wall folding device for a paper container for storing drinks such as milk or juice, which is made by folding and assembling a paper-based material in general. Regarding

[Prior Art] A paper container 1 for filling and sealing a liquid shown in FIG. 5 is formed of a sleeve-shaped cardboard whose both surfaces are coated with a thermoplastic resin. The bottom wall of the container 1 is preliminarily provided with a required ruled line, and is subjected to heating, temporary folding, and cooling / sealing steps to be liquid-tightly molded.

That is, as shown in FIG. 6, bottom edge ruled lines 2 and 4 are respectively formed on each pair of side walls facing each other, diagonal ruled lines 3 and 3 are attached to one side wall pair, and one side wall pair 1 is formed. Indicates a reverse folding ruled line 5. After this, as shown in FIG. 7, the wall surface 6 formed in a triangular shape with the ruled lines 2 and 3 is bent inward to form an inner bottom wall, and on the outer side, adjacent ruled lines 4 and 5 are formed into a rectangle. The wall surface 7 thus formed is bent and temporarily folded as an outer bottom wall.

As shown in FIG. 8 and FIG. 9, in the conventional folding device that performs temporary folding, the inner bottom wall 6 is pressed inward by the delta block 8 to be deformed, and then the outer bottom wall 7 is folded by the folding guide 9. Fold. The folding guide 9 is provided with guide surfaces 9a and 9b for smoothly guiding the end portion of the outer bottom wall 7 and deforming it into a predetermined shape.

[Problems to be Solved by the Invention] However, in the case of the conventional folding device, the folding guide 9
Is to fold while pressing the end surface of the outer bottom wall,
After the inner bottom wall 6 is bent, the delta block 8 needs to be separated from the inner bottom wall 6 in order to prevent interference with the folding guide.

Therefore, when the thick paper is thick, the above-mentioned folding device can fold it well, but when the thick paper is thin, there is a problem. That is, when the thickness of the cardboard is thin, it is difficult for the cardboard to have a crease, and the amount of deformation becomes insufficient after the delta blocks are separated. Further, since the rigidity is low, the guide surfaces 9a, 9b of the folding guide may not be able to sufficiently guide the respective edge portions, and it may not be possible to form the desired state.

Furthermore, in order to make the folding position of the bottom wall constant, it is necessary to provide a stop guide on the tip side of the mandrel on which the paper container is mounted. When the containers having different capacities are folded, the position of the stop guide needs to be changed, which complicates the structure.

The present invention has been made in view of the above, and an object thereof is to provide a bottom wall folding device for a paper container having a simple structure, which enables easy and sufficient temporary folding of a paper container using a thin material. To do.

[Means for Solving the Problems] A bottom wall folding device for a paper container according to the present invention forms an inner bottom wall by folding the opposite side faces inward in a triangular shape, respectively, and adjoining the adjacent side faces from the outside. A bottom wall folding device for a paper container, which is bent to form an outer bottom wall, wherein each of the base end sides separated from the bottom wall is pivotally attached to the tip end of an actuating shaft that can be advanced and retracted toward the bottom wall. And a pair of holding plates for folding the outer bottom wall when the actuating shaft moves toward the bottom wall and the middle portions thereof are fixed. A pair of pressing rods that are pivotally attached to the supporting member and that have delta blocks at each end that fold the inner bottom wall inward,
The other end of each of these pressing rods and a pair of links pivotally attached to the operating shaft are provided, and the delta block presses the inner bottom wall inward when the operating shaft moves toward the bottom wall. , Held in the inner position.

[Operation] According to this bottom wall folding device, when the operating shaft moves in the direction of the bottom wall, the pressing rod is operated via the link. The inner bottom wall is pressed inward by the delta block provided on the pressing rod and is held in a state of being folded inward. Adjacent outer bottom walls are drawn inward, and are further folded onto the inner bottom walls by a pair of pressing plates pivotally attached to the distal end side of the operating rod. At this time, the pressing plate evenly presses the outer bottom wall and folds it onto the inner bottom wall while changing the inclination angle against the biasing force.

Further, the edge portion of one holding plate on the base end side is arranged closer to the bottom wall than the other edge portion on the base end side, and a part of the one outer bottom wall is folded in a direction opposite to the folding direction. If
The base end side edge of the one pressing plate that is close to the bottom wall acts as a guide for folding in the opposite direction.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

[Embodiment] FIGS. 1 and 2 show the state of the cardboard blank and the folding device before folding the bottom wall, and FIGS. 3 and 4 show the state of folding.

A blank 1 formed of cardboard in the shape of a sleeve is held in place by a mandrel 1a with its bottom portion facing upward. The blank 1 is pre-scored as shown in FIG. 6, and the top of the mandrel 1a for holding the blank is formed corresponding to the inner wall of the blank 1.

The folding device 10 is provided with an actuating shaft 11 which can move up and down with respect to the bottom wall portion of the blank, and the actuating shaft is in the retracted position shown in FIGS. You can move between.

A pair of blocks 12, 12 are fixed to the tip of the operating shaft 11 facing the blank 1, and presser plates 13, 13 are pivotally attached to the tip surfaces of the blocks. The pressing plates 13 and 13 are pivotally mounted at the base end side which is separated from the bottom wall portion of the blank, and the tip side close to the bottom wall portion of the blank is urged by the coil spring 14 in the direction toward each other. Normally, it is held in a V shape as shown in FIG. Each holding plate 13 is preferably held in the range of 45 ° to 60 ° with respect to the horizontal plane.

The actuating shaft 11 further includes an actuating plate 18 fixed to the inside of the tip. Links 19, 19 are pivotally attached to both ends of the operating plate, and a pressing rod 16 is pivotally attached to each link.

The holding rod 16 is pivotally attached at its intermediate portion to a supporting member 15 fixed to the machine frame of the apparatus, and further provided with a delta block 17 facing the tip thereof. The tip of this delta block 17 is sharp, and this tip allows the triangular inner bottom wall 6 of the blank 1 to be pushed inward.

Next, the operation of the folding device 10 will be described.

From the state shown in FIGS. 1 and 2, when the operating shaft 11 descends toward the bottom wall portion, that is, the upper end of the blank, the links 19, 19 move the upper ends of the pressing rods 16, 16 outward, respectively. Since this presser rod is pivotally connected to the support member 15 at the middle portion, the delta blocks 17, 17 at the lower end are the inner bottom wall of the blank.
Move in directions 6 and 6.

As shown in FIGS. 3 and 4, when the actuating shaft 11 is further lowered, the delta blocks 17 and 17 push the inner side walls 6 and 6 inwardly, and then the presser plates 13 and 13 contact the upper edge of the blank. contact,
Insert this. When the holding plates 13, 13 are folded, the delta blocks 17, 17 continue to hold the inner bottom walls 6, 6 inward. Furthermore, since the blank 1 is provided with ruled lines in advance, the inner bottom walls 6,6 are bent in a triangular shape along the ruled lines 2,3 (Figs. 6,7), and the outer bottom walls 7,7 are It is bent in a rectangular shape along the ruled line 4 on the upper side.

When this folding is performed, the pressing plates 13 and 13 are pivotally attached to the pair of blocks 12 and 12 and are biased by springs 14 and 14 in the directions opposite to each other. After that, the angle gradually changes as the working shaft 11 advances. Then, when the actuating shaft 11 moves to the lowermost position, the outer bottom walls 7 and 7 change to an angle at which they are sufficiently folded.

As shown in FIG. 2 and FIG. 4, one upper edge of the pressing plates 13, 13, that is, the edge on the base end side that is separated from the bottom wall, is arranged closer to the bottom wall than the other. As a result, it can be folded back in the opposite direction along the reverse folding ruled line 5 (FIGS. 6 and 7).

When the actuating shaft 11 is raised after the folding is completed, the pressing rod 16 and the pressing plate 13 of the folding device 10 are respectively moved to the first position.
Returning to the position shown in FIGS. 2 and 2, the next blank can be formed.

In this example, 200 g, which is difficult to fold with a conventional device.
Although the blank 1 was formed from a thick paper having a thickness of / cm ² or less, the folding molding could be performed very well even with a blank having such a rigidity. It should be noted that folding of containers having different capacities can be easily performed by changing the position of the fold of the paper container.

[Effects of the Invention] As is apparent from the above, according to the bottom wall folding device of the present invention,
Although it has an extremely simple structure, the outer bottom wall can be folded into this outside with equal force while pressing the inner bottom wall, and the bottom of the paper container made of a material with low rigidity is extremely easy and reliable. You can temporarily fold the wall.

[Brief description of drawings]

1 to 4 show an embodiment of a bottom wall folding device according to an embodiment of the present invention, FIG. 1 is an explanatory view showing a state before folding, and FIG. 2 is a line II-II in FIG. Fig. 3 is an explanatory view showing the folded state, and Fig. 4 is an explanatory view taken along the line IV-IV in Fig. 3. 5 to 7 show a paper container, FIG. 5 is an overall view, FIG. 6 is an explanatory view showing ruled lines at the bottom, and FIG. 7 is an explanatory view showing a temporarily folded state. 8 and 9 are explanatory views showing a folded state by a conventional device. 1 …… Blank, 2,3,4,5 …… Rules, 6 …… Inner bottom wall,
7: outer bottom wall, 10: folding device, 11: actuating shaft, 13: retainer plate, 16: retainer rod, 17: delta block.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-86127 (JP, A) Sekikai 61-10828 (JP, U) JP-B 51-14950 (JP, B1) JP-B 60- 2178 (JP, B2)

Claims (2)

[Scope of utility model registration request] 1. A bottom wall folding device for a paper container, wherein opposite side surfaces are respectively folded inward in a triangular shape to form an inner bottom wall, and from the outside, adjacent side surfaces are bent to form an outer bottom wall. And at the tip of the operating shaft that can move forward and backward toward this bottom wall,
Each base end side which is separated from the bottom wall is pivotally attached, and
When the actuating shafts are urged toward each other toward the bottom wall and the actuating shafts move toward the bottom wall, a pair of holding plates that fold in the outer bottom wall and an intermediate portion between them are used as a fixed support member. A pair of presser rods that are pivotally attached to each other and have delta blocks that fold the inner bottom wall inward, and a pair of links that are pivotally attached to the other end of each of these presser rods and the operating shaft. The delta block presses the inner bottom wall inward when the actuating shaft moves toward the bottom wall, and holds the inner bottom wall in the inner position, the bottom wall folding device for a paper container. 2. The pair of presser plates are arranged such that one edge of the base end side is closer to the bottom wall than the other edge of the base end side, and a part of the one outer bottom wall is formed. The bottom wall folding device according to claim 1, wherein the folding device is folded in a direction opposite to the folding direction.