Slewing device for screw caps and method for putting screw caps on containers

• US 5,321,935 A
• Filed: 10/08/1992
• Issued: 06/21/1994
• Est. Priority Date: 04/09/1990
• Status: Expired due to Term

• Current Assignee: Alcoa Deutschland GmbH (Howmet Aerospace, Inc.)
• Original Assignee: Alcoa Deutschland GmbH (Howmet Aerospace, Inc.)
• Inventors: Schwarz, Wolfhard, Spatz, Gunter
• Primary Examiner(s): Culver, Horace M.
• Application Number:
  US07/934,542
• Time in Patent Office: 621 Days
• Field of Search: 53/490, 53/75, 53/77, 53/76, 53/317, 53/331.5, 53/53
• US Class Current: 53/490
• CPC Class Codes: B67B 3/208 Electrical means responsive to the torque applied and acting on motor control means, e.g. strain gauges or power measurement means B67B3/2093 takes precedence
• CPC Class Codes: B67B 3/26 Applications of control, warning, or safety devices in capping machinery

Abstract

A slewing device for screw closures for containers includes a screw closure receiving member, a drive for rotating the receiving member, and a control arrangement for controlling power supply to the drive and including a torque sensor for sensing an instantaneous drive torque, a comparator for comparing the instantaneous drive torque with a closing torque having a predetermined value, and a sensor for sensing an angle of rotation of the receiving member and actuatable only upon the instantaneous drive torque reaching the predetermine value. The method of placing a screw closure on a container includes applying a drive torque to the screw closure to screw it down onto the container, sensing an instantaneous drive torque applied to the screw closure, comparing the instantaneous drive torque with a closing torque having a predetermined value, and sensing an angle of rotation of the screw closure only upon the instantaneous drive torque reaching the predetermined value of the closing torque.

Claims

1. A slewing device for screw closures for containers, comprising:

a screw closure receiving member;

a drive for rotating said receiving member; and

control means for controlling power supply to said drive, said control means including;

a torque sensor for sensing an instantaneous drive torque;

comparator means for comparing the instantaneous drive torque with a closing torque having a predetermined value; and

a sensor for sensing an angle of rotation of said receiving member and actuatable only upon the instantaneous drive torque reaching the predetermined value.

2. A slewing device according to claim 1, wherein said torque sensor comprises at least one of a current sensor and a voltage sensor forming part of a power supply circuit for said drive.

3. A slewing device according to claim 1, further comprising a power reversal circuit associated with said control means.

4. A slewing device according to claim 3, wherein said torque sensor is associated with said power reversal circuit.

5. A method of placing a screw closure on a container, comprising the steps of:

applying a drive torque to the screw closure to screw it down onto the container;

sensing an instantaneous drive torque applied to the screw closure;

comparing the instantaneous drive torque with a closing torque having a predetermined value; and

sensing an angle of rotation of the screw closure only upon the instantaneous drive torque reaching the predetermined value of the closing torque.

6. A method according to claim 5, wherein said drive torque sensing step includes sensing at least one of a current and a voltage of power supply for driving the screw closure.

7. A method according to claim 5, further comprising the step of rotating the screw closure, after the enclosing torque of a predetermined value is reached, a predetermined angular amount.

8. A method according to claim 5, further comprising the step of determining a chronological change of the closing torque.

9. A method according to claim 5, wherein said step of sensing an angle of rotation includes comparing an instantaneous angle of rotation with a predetermined angle of rotation.

10. A method according to claim 5, further comprising the steps of reversal of power supply, and determining an opening moment as soon as a rotational angle of the screw closure exceeds 0°

.

11. A method according to claim 5, further comprising the steps of selecting the predetermined closing torque as a limiting torque exceeding a desired closing torque, and rotating the screw closure through a predetermined angle counter a closing direction when the limiting torque is reached.

12. A method according to claim 5, further comprising the step of initiating an additional closing process upon a determination of at least one of a defective angular value and a defective torque value.

13. A method according to claim 5, further comprising the step of sorting out a container upon sensing at least one of a defective angular value and a defective torque value.