Thermoforming machine

Abstract

A thermoforming machine for manufacturing articles from a heated thermoplastic film includes a molding station, an extraction device, a hole punch; and a stacking station. The hole punch includes a pivotable lower punching tool which receives punched-out articles from the extraction device while being pivoted into a tilted position facing the extraction device and which pivots into a vertical 0 position to face an upper punching tool for punching operation.

Claims

1. A thermoforming machine for manufacturing articles from a heated thermoplastic film, comprising: a molding station with a molding and punching tool having an upper tool and a lower tool, the lower tool being arranged pivotably around a horizontal axis on a tool table which moves in an opening and a closing direction; an extraction device arranged downstream of the molding station in travel direction of the thermoplastic film, the extraction device having suction mandrels which grip punched-out articles from the lower tool while the lower tool is in a tilted position; a hole punch with a lower punching tool that is pivotable around a horizontal axis and an upper punching tool which is driven in a raising and lowering manner, the upper punching tool being fitted with punching dies; and a stacking station arranged downstream of the hole punch, wherein the lower punching tool receives the punched-out articles from the extraction device while being pivoted into a tilted position facing the extraction device and wherein the lower punching tool pivots into a vertical 0 position to face the upper punching tool for punching operation.

2. The thermoforming machine according to claim 1, wherein the lower punching tool is arranged on a pivot table.

3. The thermoforming machine according to claim 1, wherein the hole punch is arranged in line with the molding station and the stacking station, wherein the lower punching tool can pivot both in and against the travel direction of the thermoplastic film, wherein a linearly movable swivel catching device is arranged between the molding station and the hole punch, and wherein a second swivel catching device is arranged in the stacking station behind the hole punch.

4. The thermoforming machine according to claim 3, wherein the lower punching tool can pivot by a total of 180.

5. The thermoforming machine according to claim 1, wherein the hole punch is arranged offset to one side of a line formed by the molding station and the stacking station, wherein the upper punching tool and the lower punching tool extend orthogonal to the molding and punching tool of the molding station, wherein the lower punching tool is pivotable towards the line, and wherein the extraction device is formed as an article handling unit with linearly adjustable plates that are equipped with suction mandrels, the linearly adjustable plates being arranged on a support frame which is rotatable around a vertical axis.

6. The thermoforming machine according to claim 5, wherein the lower punching tool can pivot by 90.

7. The thermoforming machine according to claim 5, wherein the article handling unit comprises four plates that are arranged at right angles relative to each other and linearly adjustable independently of each other, and wherein the support frame is rotated in sequence such that one plate faces the molding station, one plate faces the hole punch, one plate faces the stacking station, and one plate occupies a waiting position, the plate facing the molding station and the plate facing the stacking station being arranged on opposite sides of the support frame.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the molding station of a thermoforming machine with a tool that is still open and consists of two halvesan upper and lower tool.

(2) FIG. 2 shows a first version of a thermoforming machine, with a molding station, a hole punch and a stacking station arranged in a line.

(3) FIG. 3 shows a second version of a thermoforming machine with the hole punch being arranged offset to one side from the line of the molding and stacking station.

DETAILED DESCRIPTION

(4) Referring to FIG. 1 a molding station 1a of a thermoforming machine (see FIGS. 2 and 3) is shown in detail. The molding station 1a includes a two-part, molding and punching-out molding tool 4, consisting of a lower tool 2 and an upper tool 3. For the manufacturing of deep-drawn, arbitrary items (such as bowls, cups or pots), a previously heated synthetic film 7 (which is, for example, unwound from a roll 6) intermittently enters in the travel direction 5 of the film.

(5) The upper tool 3 is fixed to a stationary upper yoke 8, while the lower tool 2 is designed as a movable tool half, which moves relative to the upper tool 3. A combined translational and pivoting movement is used in order to, after the shaping and punching out of the articles, be able to more easily remove them and lead them away. The movement of the lower tool 2 is accomplished by a toggle lever 9, at which a cam disk 10 is set. Through this movement mechanism, a lower table or tool table 11, on which the lower tool 2 is mounted, is moved relative to a lower yoke 12. During the movement of the cam disk 10, the molding tool 4 with its lower and upper tool 2, 3 is accordingly opened or closed. The closing direction of the tool is indicated by an arrow S.

(6) The swinging out of the lower tool 2 with its molds arranged in one or more rows corresponding to the number of products to be manufactured into a tilted extraction position as shown in FIG. 1 takes place via a horizontal axis of rotation 13.

(7) A thermoforming machine for manufacturing articles which include holes has a hole punch 1b following the molding station 1a. Arranged subsequently to the hole punch 1b is a stacking station 1c, which may be formed as a well-known stacking and counting device that is otherwise directly downstream of the molding station (see FIGS. 2 and 3).

(8) As shown in FIG. 2, the hole punch 1b is formed with a movable upper punching tool 14 that can be raised and lowered and lower punching tool 15. The upper punching tool 14 has a number of punching dies or cutting punches that corresponds to the number of articles. The lower punching tool 15 includes article receptacle in a single-row or multi-row arrangement corresponding to the configuration of molds of the lower tool 2 of the molding station 1a. The lower punching tool 15 is arranged on a pivot table 16 that is pivotable around a horizontal axis 16a. The pivot table 16 with the lower punching tool 15 forms the counter tool for the upper punching tool 14, which raises and lowers with the punching dies.

(9) With the design of the thermoforming machine 1 according to FIG. 2, the molding station 1a, the hole punch 1b and the stacking station 1a are arranged in a line. A linearly movable swivel catching device 17 is arranged between the molding station 1a and the hole punch 1b. The swivel catching device 17 receives the molded and punched-out articles from the molding station 1a while its lower tool 2 is in a tilted position as shown in FIG. 1. The swivel catching device 17 has a turning plate 19 which is fitted with multi-row suction mandrels 18, as predetermined by the number of molds of the lower tool 2. The turning plate 19 is pivotable up to 180 around a horizontal axis 19a.

(10) In the illustrated transfer position, the suction mandrels 18 are facing the lower tool 2 of the molding station 1a. After the transfer of the articles, the turning plate 19 is pivoted by 180, such that the suction mandrels 18 with the received articles face the lower punching tool 15. The lower punching tool 15 and its receptacles are pivoted by 90 against the travel direction of the film 5 to face the turning plate 19. The swivel catching device 17 is then moved towards the lower punching tool 15, such that the articles can be subsequently ejected into the receptacles of the lower punching tool 15. The lower punching tool 15 with the received articles is then pivoted back, for punching, by 90 into exactly the 0-degree home position, in which the holes can be punched out with a 100-percent accuracy. As soon as the punching out is completed, the upper punching tool 14 is raised and the lower punching tool 15 is pivoted in the travel direction of the film 5 by approximately 80 towards the stacking station 1c. There, the perforated finished articles are taken up by a swivel catching device or a turning plate stacker 20, and are discharged on a conveyor belt 21 (see FIG. 3) for counting and stacking, and possibly removal.

(11) The thermoforming machine 1 shown in FIG. 3 differs from the previously described design in that the hole punch 1b is no longer arranged in a line with the other parts of the system. Rather, it is provided in a manner that is offset to one side from the line, and the lower punching tool 15 no longer needs to be pivoted by 180, but only needs to be pivoted by 90. Furthermore, the extraction device 17 is no longer pivotable by 180. Rather, it is formed as an article handling unit with plates 24 which are equipped with suction mandrels 18. The plates 24 are arranged linearly adjustable on a support frame 23. The support frame 23 is rotatable around a vertical axis 22. Four plates 24 are arranged at right angles to each other and are independently linearly adjustable on the support frame 23, as indicated by the double arrows 25.

(12) In operation of the thermoforming machine 1 the film 5 is unwound from the roll 6 and heated by a heating device in the travel direction of the film 5. The film 5 arrives in the molding station 1a, the lower tool 2 of which, after the molding and punching out of the articles, is brought into a tilted position by pivoting in the direction of the removal device 17. The plate 24 turned towards the molding station 1a is moved linearly and picks up the articles with its suction mandrels 18. By turning the support frame 23, this plate arrives in front of the hole punch 1b, which is laterally offset from the line. The lower punching tool 15 is in a position swung out by 90 in the direction of the plate 24 and receives the articles ejected from the suction mandrels 18. For punching the holes, the lower punching tool 15 is pivoted back into the vertical 0 position in the hole punch for punching the holes. Upon completion of the hole punching, the upper punching tool 14 of the hole punch 1b is raised, and the lower punching tool 15 is pivoted back by 90 in the direction of the extraction device 17. Then the now perforated articles are picked up by the suction mandrels 18 of the plate 24 and, through the rotation of the support frame 23, brought in front of the swivel catching device 20 of the stacking station 1c. After received the articles in its suction mandrels the swivel catching device 20 pivots in the travel direction of the film 5 and leads the articles into the stacking station 1c. There the articles are stacked inside of each other into rods and can be expelled onto a conveyor belt 21 by means of push units 26 shown in FIG. 3.

(13) Since the three stations of the thermoforming machine 1 are allocated four plates 24 with suction mandrels 18, with each rotation of the support frame 23, one plate is always in front of the molding station 1a, one in front of the hole punch 1b and one in front of the stacking station 1c. The remaining fourth plate occupies a waiting position. A process flow that is only interrupted by molding and hole punching cycles, but is otherwise continuous, is thereby achieved, and the cycle sequence can be set by the hole punch 1b instead of the molding station 1a.

(14) While the present invention has been described with reference to exemplary embodiments, it will be readily apparent to those skilled in the art that the invention is not limited to the disclosed or illustrated embodiments but, on the contrary, is intended to cover numerous other modifications, substitutions, variations and broad equivalent arrangements that are included within the spirit and scope of the following claims.