US 4,361,260 A · Web registration control

Abstract

A register control (21) is provided for a web handling apparatus (22) having a drive motor (29) operatively moving a web (23) containing repetitive indicia (34) through a sequencially operating function apparatus (27) performing repetitive operations on the web. A control (41) responds to the speed of the drive motor (29) and the position of the function apparatus (27) and the position of the indicia (34) to provide a speed command signal (V.sub.c) to a full wave regenerative thyristor control circuit (38) to operatively control the operating speed of a pair of nip rolls (25, 26) through the controlled energization of a corrective motor (35) to maintain registration between the function apparatus (27) and the indicia (34). The control (41) provides a timed modification to a sensed speed signal V.sub.s for providing a modified speed command signal (V.sub.c) when the system is out of registration. A speed command modification circuit (213) responds to an advance modification timing circuit ( 79) and an advance coincidence circuit (81) to increase the speed of the correction motor (35) and responds to a retard timing modification circuit (78) and a retard coincidence circuit (80) to decrease the operating speed of the correction motor (35).

Claims15

Dependent claims

A register control for web handling apparatus having drive motive means operatively moving a web containing repetitive indicia and a sequentially operating function apparatus performing repetitive operations on said web corresponding to said repetitive indicia and corrective motive means positively rotating an associated drive roll which engages and moves said web in a predetermined relationship with respect to said drive motive means, said register control comprising

first sensing means operatively connected to said drive motive means to provide a speed responsive signal,
second sensing means operatively connected to said function apparatus to provide a function indicating signal,
third sensing means operatively scanning said web to provide an indicia indicating signal, and
modification means operatively connected to said first, second and third sensing means and operable between a first condition providing a first speed command signal to operate said corrective motive means in direct response to said speed responsive signal when the operation of said function apparatus is in register with said indicia and a second condition providing a second speed command signal responsive to said speed responsive signal modified in response to said function indicating signal and said indicia indicating signal to operate said corrective motive means when the operation of said function apparatus is out of register with said indicia to thereby vary the operating speed of said corrective motive means to regain registration between said function apparatus and said indicia.

1 more element

A register control for web handling apparatus having motive means operatively moving a web containing repetitive indicia and a sequentially operating function apparatus performing repetitive operations on said web corresponding to said repetitive indicia, said register control comprising

drive means responding to a speed command signal to energize said motive means to move said web at a speed relating to said speed command signal,
sensing means operatively connected to said web handling apparatus and providing a speed signal indicative of an operating speed of said web handling apparatus,
modifying means operatively connected to said sensing means and to said drive means to provide said speed command signal in response to said speed signal and selectively operable between a first condition to provide a first speed command signal and a second condition to provide a second speed command signal, and
transfer means operatively connected to respond to the position of said function apparatus and the position of said indicia to transfer said modifying means from said first condition to said second condition in response to said function apparatus being out of register with said indicia to provide said second speed command signal to modify the operation of said drive means to regain registration between said function apparatus and said indicia.

1 more element

A register control system for web handling apparatus having first and second draw rolls sandwiching a substantially continuous web of pliable film therebetween, first and second function rolls sandwiching said web therebetween with said first function roll providing an operation on said web, and an electrical drive motor operatively connected to said second function roll to rotate said first and second function rolls to thereby move said web through said web handling apparatus and provide an operation on said web by said first function roll, said register control system comprising

(A) a correction motor operatively rotating said first draw roll in a first direction to control the speed of the web passing between said first and second draw rolls,
(B) a full wave regenerative, thyristor controlled motor speed control having an output connected to continuously and variably control the operation of said correction motor,
(C) a tachometer connected to said drive motor to provide a line speed electrical signal having a relationship to the web speed at said first and second function rolls,
(D) a registration scanner including a photo-responsive circuit to sense a plurality of web containing marks each indicative of a single repetitive pattern on said web to provide a mark detection pulse for each sensed mark;
(E) a function position sensor connected to said first function roll and including
(1) a disc connected to rotate in synchronism with the rotation of said first function roll,
(2) a first permanent magnet connected to said disc,
(3) a second permanent magnet connected to said disc and circumferentially spaced from said first permanent magnet,
(4) a first magnetic sensor connected to monitor the magnetic field strength of said first magnet,
(5) a second magnetic sensor connected to monitor the magnetic field strength of said second magnet,
said first and second magnetic sensors angularly adjustable with respect to each other to provide a predefined dead sensing zone and a selectively adjustable advance sensing zone and retard sensing zone with said first magnetic sensor providing an advance pulse in response to said first magnet being within said advance zone and said second magnetic sensor providing a retard pulse in response to said second magnet being within said retard zone,
(F) registration control circuit means connected to receive said line speed signal, said mark detection pulse, said advance pulse and said retard pulse and providing a speed comand signal to said motor speed control to operatively control the operating speed of said correction motor, said registration control circuit means providing
(1) a speed command modification circuit including
(a) a first selectively variable modification circuit connected to receive said line speed signal and operable between a first condition to provide a non-modified speed output signal and a second condition to provide an advance modified speed output signal,
(b) an analog-to-digital converter operatively connected to said first selectively variable circuit and providing a digital output having a frequency proportional to the magnitude of said non-modified or advance modified speed output signals,
(c) an opto-isolator having an input operatively connected to said analog-to-digital converter to respond to said digital output and providing an optically isolated digital output corresponding in frequency to said digital output,
(d) a digital-to-analog converter operatively connected to receive said optically isolated digital output from said opto-isolator to provide an analog output having a magnitude proportional to said digital output, and
(e) a second selectively variable modification circuit connected to receive said analog output and operable between a first condition to provide a non-modified response and a second condition to provide a retard modified response for providing said speed command signal to said motor speed control,
(2) an advance coincidence circuit connected to said registration scanner and to said function position sensor to provide an advance coincidence pulse in response to the simultaneous occurrence of said mark detection pulse and said advance pulse,
(3) an advance modification timing circuit connected to said advance coincidence circuit and to said first modification circuit to provide an advance command pulse of a predetermined duration in response to said advance coincidence pulse to transfer said first modification circuit from said first condition to said second condition to provide said advance modification output for said predetermined duration to correspondingly modify said speed command signal for said predetermined duration to increase the speed of said correction motor for increasing the web speed to regain registration between each sensed mark and the positioning of said first function roll,
(4) a retard coincidence circuit connected to said registration scanner and to said function position sensor to provide a retard coincidence pulse in response to the simultaneous occurrence of said mark detection pulse and said retard pulse, and
(5) a retard modification timing circuit connected to said retard coincidence circuit and to said second modification circuit to provide a retard command pulse of a predetermined duration in response to said retard coincidence pulse to transfer said second modification circuit from said first condition to said second condition to provide said retard modification response for said predetermined duration to correspondingly modify said speed command signal for said predetermined duration to decrease the speed of said correction motor for decreasing the web speed to regain registration between each sensed mark and the positioning of said first function roll.

19 more elements

Dependencies are inferred from the claim text.

Web registration control

Life of this patent

Web registration control

Life of this patent

Abstract

Claims15