GB2139182A - Synchronized motor control particularly adapted for use with apparatus for making tubular articles - Google Patents

Abstract

A control, for winding machines having a rotatable mandrel (11), a material applicator (15) and a pair of bidirectional D.C. motors (12,16), one for rotatably driving the mandrel and the other providing relative transverse movement between the mandrel and the applicator, comprises a pair of control assemblies (21,23) for driving the motors and a pair of optical encoders (13,17) monitoring the motors and providing pulses representing discrete increments of each revolution of each motor to a synchronization assembly (2) establishing a predetermined ratio to control the rate of rotation of the motor (12) driving the mandrel to the rate of rotation of the other motor (16). A computer (30) has means for writing and storing programs for winding tubular articles and for retrieving a stored program. The computer is connected to provide signals to the motor control and synchronization assemblies and to receive pulses from the encoder monitoring the motor driving the mandrel. A switch is connected to block ratio-establishing signals to the synchronization assembly from the computer and to manually establish the ratio. The controls are also provided to manually control the full winding operation in lieu of the computer. <IMAGE>

Description

SPECIFICATION Synchronized motor control particularly adapted for use with apparatus for making tubular articles This invention relates generally to strip winding machines or apparatus and more particularly to controls therefor.

While strip winding machines or apparatus and their controls are known in the art, modern technology requires controls with more accuracy and versa tilitywhich can rapidly be reprogrammed for wrapping various materials on a cylindrical drum or mandrel for making tubular particles of various sizes, wall thicknesses and profiles with the same equipment. Examples of strip winding machines with rotating drums or mandrels are provided by U.S. patents 3,716,442 and 3,726,736 illustrating lateral movement between a spinning drum or mandrel and an applicator assembly, and which by reference are made part of the present disclosure.

U.S. patent 4,206,009 which by reference is also made part of the present disclosure, provides a showing of a strip winding machine having a computer type control for winding elastomer strips on used tire carcasses.

Although the aforenoted patents are substantially limited to winding elastomer strip, the present invention contemplates winding cords, cloth strips, elastomeric materials and/or combinations thereof, hereinafter called strip material on mandrel or a cylindrical drum; and further providing selective control of the direction of spin and lateral direction of the wrap or winding.

It should be readily realized that the density of the wrap, the number of winds per unit of length along the drum or mandrel, is determined by the controlled ratio between the spin drive and the lateral transport drive and the wall thickness of a tubular member of constant profile also can be controlled by the number of passes the applicator makes along the length of the drum or mandrel. However, to obtain an irregular profile, each pass is segmented and the ratio between the spin and lateral drives is adjusted according to the density of the windings required for each segment to provide the profile desired.

An object of the present invention is to provide rapid, accurate and readily adjustable control means for apparatus for winding tubular articles of various sizes, profiles and wall thicknesses.

Another object of the present invention is to provide the foregoing control means which automatically synchronizes the spin and lateral transport drives of the winding machine or apparatus in accordance with a prepogram determined by the product to be made.

And another object of the present invention is to provide the foregoing control means for determining the direction of spin of a drum or mandrel and lateral movement between the spinning drum or mandrel and a material applicator assembly.

The foregoing and other objects and advantages will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawing wherein a single embodiment of the invention is illustrated by way of example. It is to be expressly understood that the drawing is for illustration purposes only and is not to be construed as defining the limits of the invention.

The single figure is a functional block diagram of a control in accordance with the present invention.

At the outset it should be understood that the present invention does not claim the specific construction of a strip winding machine or of a computer beyond that which is necessary to provide the novel functional control.

As diagrammatically shown, a winding machine or apparatus 10 is provided with a bidirectional D.C.

motor 12 for spinning or rotatably driving a cylindrical drum or mandrel 11 upon which a tubular article is to be made and an applicator assembly 15 for applying a strip material such as cord, wire, cloth, elastomer material, etc., on to the rotating drum or mandrel. A bidirectional D.C. motor 16 is provided, as shown, to move the applicator assembly 15 laterally or transversely relative to the material being wound or parallel to the axis of rotation of the drum or mandrel 11. However, it should be realized that it is a matter of choice to move the applicator assembly 15 relative to the rotating drum or mandrel 11, or to move the drum or mandrel axially relative to the applicator assembly which would be retained in a fixed position; such movement hereinafter will be discussed as relative movement.

A digital encoder 13 is provided to monitor the rotation of motor 12 and provide pulse signals representing discrete increments of each revolution of the motor and thereby the drum or mandrel 11. A second digital optical encoder 17 is provided to monitor the rotation of motor 16 and provide pulse signals representing discrete increments of each revolution of the motor and thereby the relative movement between the drum or mandrel 11 and the applicator assembly 15.

The machine or apparatus 10 also has a switch 14 to provide a zero position signal for the drum or mandrel 11, and a spaced pair of limit switches 18 and 19 to provide a signal when the applicator assembly 15 is in wether a left or right "home" position.

Motors 12 and 16 are controlled or driven by control assemblies 20 and 21 and a programmable ratio shaft rotation synchronization assembly 22 which receives pulsesfrom the encoders 13 and 17 electronically links the rotational rate of motor 16 or lateral movement of the applicator assembly 15 to the rotational spin rate of the motor 12 and the drum or mandrel 11. The output of the synchronization assembly 22 is connected through the control 21 to the motor 16. The synchronization assembly 22 comprises circuitry for performing the function of modifying the count of the input from the master encoder 13 monitoring rotation of the motor 12 according to a preprogrammed ratio established automatically by a computer 30 or manually by a set-in or thumb wheel switch 26.The circuit elements consist of a voltage controlled oscillator, a phase detector, a programmable driver, and such circuitry as is required to discriminate the value of the ratio establishing input. The circuit operates in a well known manner of a phase-lock loop. With inputs from both encoders 13 and 17, the synchronization assembly 22 with its preprogrammed ratio will provide an output to motor control assembly 21 which will cause the rotation rate of motor 16 to follow or change in response to changes of rotation rate of the motor 12.

The computer 30 is essentially of a general purpose type provided with a central processing unit (C.P.U.) and memory 31, the usual keyboard 32 for writing programs and manual operation of the computer, and control circuits such as circuits 33 for an optional printer 34 and a floppy disc drive 35. The computer 30 also has the usual counter means or circuits 36 and input/output circuits 37 connecting the C.P.U. and memory 31 to the motor control assemblies 20 and 21, the synchronization assembly 22 and an operator's manual control 25 as will be discussed.A C.R.T. 38 is provided to monitor the computer 30 which has a 0 to 9 keypad 39 for retrieving or recalling a particular stored program when the keyboard is normally locked to prevent an operator from unauthorized or inadvertently changing a particular program when the controlled machine is in use.

The manual control 25 is capable of overriding the computer 30 from operating the machine 10 automatically in accordance with a retrieved or recalled program to permit manual operation by an operator, and has the set-in or thumbwheel switch means 26 to manually establish the desired ratio in synchronization assembly 22.

For a better understanding of the present invention it should be readily realized that by use of the keyboard 32 various programs can be written which are stored in the computer 30. Each program can be written which are stored in the computer 30. Each program will be appropriately identified and when retrieved will provide visible identifying information on the C.R.T. 38 to a machine operator including the material to be wound. The program will initially set up the machine to a zero-zero condition in which the switch 14 provides a signal representing the zero angular position of the mandrel 11 and one of the switches 18 or 19 provides a signal indicating the arrival of the applicator assembly 15 at either a left or right home position.The program will establish the direction of rotation, clockwise or counterclockwise, of the mandrel 11; the direction of relative move ment, left or right, between the mandrel 11 and the applicator assembly 15; and the desired ratio of rotation of motors 12 and 16.

Each program will include one or more sequences, each providing control for a single pass of the applicator assembly 15 relative to the mandrel 11.

Each sequence will embody a single segment when no variations in the wrap are required. However, when making a profiled tubular product or a tubular product with a wall of varying density, the sequence will embody a plurality of segments each with a predetermined ratio defined by the relative positions of said application assembly 15 and the mandrel 11, and the rotational position of the mandrel. The pulse signals from the encoder 13, in addition to being directed into the synchronization assembly 22, are provided as input signals to counter means 36 to define the end of a sequence or segment of a sequence.

The set-in or thumbwheel switch 26 is so arranged to block ratio establishing signals from the computer 30 and to manually establish a fixed ratio in the synchronization assembly 25. After a program is retrieved or recalled by use of the keypad 39, a machine operator by use the usual controls of the operator's console 25 such as automatic (operation) manual (operation), build and stop initiates operation of the machine 10. This invention also contemplates total manual machine control by also providing the console 25 controls to establish spin and wrap directions.

Although a single embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

Claims (7)

1. A control for a strip winding machine having a rotatable mandrel, an applicator assembly and a pair of bidirectional D.C. motors one for rotatably driving said mandrel and the other four providing relative transverse movement between said mandrel and applicator assembly to wind tubular articles, comprising: a pair of control assemblies electrically connected each for driving a different one of said motors; a pair of encoders each monitoring a different one of said motors and providing pulse signals representing discrete increments of each revolution of said monitored motor; a synchronization assembly connected to receive pulse signals from said encoders and to provide an output to the control assembly for said motor providing such relative movement in accordance with an established ratio thereby controlling the relative rotation of said motors; and a computer having means for writing and storing a plurality of programs, and for selectively retrieving a stored program for use; said computer being connected to said synchronization assembly to provide signals to establish the motor rotation ratio in accordance with the retrieved program.

2. A control in accordance with claim 1, and a set-in switch connected to block ratio establishing signals from said computerto said synchronization assembly, and to manually establish the ratio of said synchronization assembly.

3. A control in accordance with claim 1, and said computer means being connected to provide signals to said control assemblies causing each of said motors to rotate in a predetermined direction in accordance with the retrieved program.

4. A control in accordance with claim 3 wherein each program has at least one sequence with a predetermined direction of rotation of said motors during each sequence, and each sequence has at least one segment with a predetermined ratio of relative rotation of said motors, and, said computer means being connected to receive pulse signals from said encoder monitoring said motor rotatably driving said mandrel and having means responsive to such pulse signals for determining the end of one sequence and providing motor direction signal for the next successive sequence, and for determining the end of one segment and providing signals to establish a motor rotation ratio for the next successive segment.

5. A control in accordance with claim 4 wherein said machine includes a zero mandrel set switch and a pair of limit switches at the left and right home position of said applicator assembly relative to said mandrel, and said computer providing zero-zero signals to said motor control assemblies at the beginning of a program to set the machine in a home position and being connected to receive a signal from said zero set switch and one of said limit switches to indicate the machine is in the home position.

6. A control in accordance with claim 5, and a set-in switch connected to block ratio establishing signals from said computer to said synchronization assembly, and to manually establish the ratio of said synchronization assembly.

7. A control for a strip winding machine substantially as described with reference to the accompanying drawing.