Measurement of the boxing travel by the stretching function, in an installation for producing containers

Patent metadata

Field	Value
Publication number	US-10343327-B2
Application number	US-201515325509-A
Country	US
Kind code	B2
Filing date	Jul 2, 2015
Priority date	Jul 11, 2014
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

Disclosed is a method for parametrizing a facility for producing containers including: a mold having a movable mold bottom, a movable drawing rod and an electric machine coupled with the rod; from a configuration in which the rod is in a raised position and in the bottom in an extended position, operating the electric machine as a motor; assessing the resultant of the axial forces on the rod; when a variation is detected in the resultant of the forces, assigning an initial position to the rod; controlling the movement of the mold bottom towards the retracted position thereof; assigning to the rod the corresponding so-called final position of the rod; and calculating the difference between the final position and the initial position.

First claim

The invention claimed is:

1. A method using a central control unit with a memory for operating an installation for manufacturing containers by stretch blow molding from blanks made of plastic material, where the installation includes a mold with a wall that defines a cavity bearing an impression of the container and extending along a main axis of the mold and with a mold bottom that is movable axially in relation to the wall between an extended position and a retracted position, a moving device configured to exert an axial thrust on the mold bottom to move the mold bottom from said extended position to said retracted position and vice versa, a stretching device with and electric machine and a stretching rod that is movable axially in relation to the wall, the stretching rod actuated by the electric machine, and a central control unit with a memory and in operative communication with the moving device and the stretching device, said operating method comprising:
from an initial configuration in which the stretching rod is in a raised position away from the mold bottom and in which the mold bottom is in one of said extended position and said retracted position, controlling the electric machine to operate as a motor to apply an axial driving force on the stretching rod that moves the stretching rod toward the mold bottom;
evaluating a result of axial forces exerted on the stretching rod;
on condition that a variation in the result of the forces is detected, determining and storing in the memory of the central control unit a position of origin for the stretching rod;
controlling the mold bottom to move toward the other of said retracted position and said extended position;
determining and storing in the memory of the central control unit a corresponding final position for the stretching rod; and
calculating and storing in the memory of the central control unit a travel of the stretching rod as a distance between the final position and the position of origin.

2. The method according to claim 1 , wherein, in the initial configuration, the mold bottom is in said extended position.

3. The method according to claim 2 , further comprising:
between the determining and storing of the position of origin and the controlling of the mold bottom to move toward said retracted position, a step of ceasing to apply the axial driving force on the stretching rod.

4. The method according to claim 3 , wherein the ceasing of the axial driving force on the stretching rod is includes a step of causing the electric machine to stop operating as a motor.

5. The method according to claim 4 , wherein after the causing of the electric machine to stop operating as a motor and before the controlling of the mold bottom to move toward said retracted position, the electric machine is switched to operate as a generator.

6. The method according to claim 5 , further comprising:
after the controlling of the mold bottom to move toward said retracted position, a predetermined time delay.

7. The method according to claim 4 , further comprising:
after the controlling of the mold bottom to move toward said retracted position, a predetermined time delay.

8. The method according to claim 3 , further comprising:
after the controlling of the mold bottom to move toward said retracted position, a predetermined time delay.

9. The method according to claim 2 , further comprising:
between the determining and storing of the position of origin and the controlling of the mold bottom to move toward said retracted position, a step of repositioning the rod into said raised position.

10. The method according to claim 2 , further comprising:
after the controlling of the mold bottom to move toward said retracted position, a predetermined time delay.

11. The method according to claim 2 , further comprising:
comparing the travel of the stretching rod with a predetermined theoretical value.

12. The method according to claim 1 , further comprising:
between the determining and storing of the position of origin and the controlling of the mold bottom to move toward the other of said retracted position and said extended position, a step of repositioning the stretching rod into said raised position.

13. The method according to claim 12 , further comprising:
after the controlling of the mold bottom to move toward the other of said retracted position and said extended position, steps of:
moving the stretching rod from said raised position toward the mold bottom;
evaluating the result of the axial forces exerted on the stretching rod;
upon a variation in the result of the forces being detected, assigning said final position to the stretching rod.

14. The method according to claim 13 , further comprising:
after the controlling of the mold bottom to move toward the other of said retracted position and said extended position, a predetermined time delay.

15. The method according to claim 13 , further comprising:
comparing the travel of the stretching rod with a predetermined theoretical value.

16. The method according to claim 12 , further comprising:
after the controlling of the mold bottom to move toward the other of said retracted position and said extended position, a predetermined time delay.

17. The method according to claim 12 , further comprising:
comparing the travel of the stretching rod with a predetermined theoretical value.

18. The method according to claim 1 , further comprising:
after the controlling of the mold bottom to move toward the other of said retracted position and said extended position, a predetermined time delay.

19. The method according to claim 1 , further comprising:
comparing the travel of the stretching rod with a predetermined theoretical value.

20. The method according to claim 1 ,
wherein the evaluation of the result of the axial forces exerted on the stretching rod is accomplished by measuring a current consumed by the electric machine when operating as a motor, and
wherein the detection of the variation in the result of the forces exerted on the stretching rod is achieved by detecting a variation in the current consumed by the electric machine when operating as a motor.

Assignees

• Sidel Participations

Inventors

• Protais Pierrick

Classifications

• G05B19/406

  characterised by monitoring or safety (G05B19/19 takes precedence) · CPC title

• B29K2067/003

  PET, i.e. poylethylene terephthalate · CPC title

• G05B2219/49025

  By positioning plurality of rods, pins to form together a mold, maquette · CPC title

• B29L2031/712

  Containers; Packaging elements or accessories, Packages (closures therefor B29L2031/56; ink or toner cartridges B29L2031/7678; squeeze tubes B29L2023/20; suitcases B29L2031/7418) · CPC title

• B29C49/4815

  by means of movable mould parts · CPC title