Spring biased spool type valve controller for a pneumatic dual diaphragm control system

Abstract

The invention relates to a direct acting pneumatic control system for controlling a dual diaphragm, or double acting cylinder type automatic guiding system. The control device and system is used to selectively adjust the position of one end of a roll relative to the opposite end, in order to adjust the position of an endless web traveling over a series of rolls.In order to adjust and control the guide roll position, it is necessary to alternately exhaust one diaphragm, and or cylinder end, while maintaining the flow of air to the opposite diaphragm or cylinder end. This in effect shifts the roll in a lateral position, effectively steering the web in the proper direction to effect the necessary web correction.To activate and control the valve position, the control valve is equipped with a palm which follows the web and continually monitors the web position and activates the control valve spool to modulate the "flow-exhaust" rates to bring the web to a corrected position with no over-run or "hunting" for position. The palm and its associated rod must follow the web when the web is moving away from the palm.

Description

Claims

1. A sliding spool type controller assembly for controlling and directing air from an air source to a pneumatic guiding mechanis:m that is operatively connected to a guide roll for moving and adjusting the guide roll so as to appropriately guide a web material over the guide roll, comprising:

A. a spool type valve having a body, a sliding spool movably mounted for back and forth movement along its longitudinal axis therein, an air inlet port, outlet ports, and exhaust ports formed therein with the outlet ports being adapted to be communicatively connected to the pneumatic guiding system;

B. biasing means operatively associated with the spool for biasing the same toward a selected position within the valve;

C. spool actuating means for engaging an edge of the material passing over the guide roll and moving the spool back and forth within the valve in response to the lateral shifting of the material as the same passes over the guide roll wherein the movement of the spool, as a result of the lateral movement of the material, results in the guiding system adjusting the position of the guide roll so as to adjust the running angle of the material passing over the guide roll;

D. the spool actuating means including pivot arm means, directly coupled to said spool, for moving and shifting the spool back and forth within the valve in response to the lateral shifting of the material passing over the guide roll;

E. the spool and pivot arm adapted to assume a first neutral position and wherein from the neutral position the pivot arm may pivot to second and third extreme positions on opposite sides of the neutral position;

F. the valve and spool including means for opening the outlet ports and exposing the same to air pressure while closing the exhaust ports in response to the spool and pivot arm assuming the neutral position, thereby preventing the valve from experiencing "hunting"; and

G. wherein the spool includes an airflow channel formed therein for directing air from the air inlet port of the valve, through the spool body onto the outlet ports of the valve, the air flow channel including an inlet air spool port formed in the spool for directing inlet air from the air inlet port of the valve into the spool, spool outlet ports formed in the spool for directing air passing through the spool to the outlet ports of the valve, and an air passage channel extending through the spool and between the inlet air spool ports and the spool outlet ports.

2. The spool type controller of claim 1 wherein said biasing neans includes a helical spring disposed within said valve body and disposed adjacent said spool so as to engage said spool and to bias the same in a selected direction.

3. The spool type controller of claim 1 wherein the pivot means includes a joint assembly operatively interconnected between the spool and the pivot arm means.

4. The spool type controller of claim 3 wherein said joint assembly includes a cavity actually formed in said spool and an opening providing access thereto, and a movable member contained within said cavity and operatively connected to said pivot arm means such that as said pivot arm is moved back and forth said spool is moved back and forth with said valve via said joint assembly converting rotary to sliding motion.

5. The spool type controller of claim 4 wherein said joint assembly is movable transversely in a direction normal to the longitudinal axis of said spool as said pivot arm means is moved back and forth.

6. The spool type controller of claim 5 further including a pivot pin connecting said pivot arm means with said valve adjacent said joint assembly.

7. The spool type controller of claim 6 including a pivot arm opening formed in said valve through which said pivot arm means projects, and wherein there is provided a flexible boot secured to said valve adjacent said pivot arm opening and which encompasses a portion of said pivot arm extending from said valve.

8. A spool type controller assembly for controlling and directing air from an air source to either side of a dual diaphragm pneumatic guiding system that is operatively connected to a guide roll for moving and adjusting the guide roll so as to appropriately guide a web material over the guide roll, said spool type controller comprising:

A. a valve having a body, a spool movably mounted therein, an air inlet port, a pair of outlet ports, exhaust port means formed therein with each outlet port being adapted to be communicatively connected to a respective diaphragm of said pneumatic guiding system;

B. biasing means operatively associated with said spool for biasing the same toward a selected position within said valve;

C. spool actuating means for engaging an edge of said material passing over said guide roll and moving said spool back and forth within said valve in response to the lateral shifting of said material as the same passes over said guide roll wherein the movement of said spool, as a result of the lateral movement of said material, results in the guiding system adjusting the position of said guide roll so as to adjust the running angle of the material passing over said guide roll;

D. wherein said spool actuating means includes pivot arm means directly coupled to said spool for moving said spool back and forth within said valve as said pivot arm means is moved back and forth, said pivot arm means including an inner end movably mounted to said spool and extending therefrom and further including a remote end having a follower secured thereto for engaging the edge of said material passing over said guide roll, such that said pivot arm means actuates and moves said spool back and forth within said valve in response to the lateral shifting of the material passing over said guide roll;

E. wherein there is provided a movable member movably mounted within a cavity associated with said spool with said movable member being movable back and forth within said cavity and valve in a direction normal to the direction of movement of said spool, and wherein a pivot arm is pivotably mounted within said movable member and connected to the inner end of said pivot arm such that as said pivot arm moves back and forth said pivot arm pivots within said movable member causing said spool to be shifted back and forth while said movable member moves transversely to the normal direction of said spool;

F. said spool and pivot arm adapted to assume a first neutral position and wherein from said neutral position said pivot arm may pivot to second and third extreme positions on opposite sides of said neutral position; and

G. wherein said valve and spool include means for opening said outlet ports and exposing the same to air pressure while closing said exhaust port means in response to said spool and pivot arm assuming said neutral position, thereby preventing the valve from experiencing "hunting".

9. The spool type controller of claim 1 where in the means for opening the outlet ports and exposing the same to air pressure when the spool assumes the neutral position includes a pair of outer raised shoulders formed on the spool. with each raised shoulder disposed adjacent a respective outlet port of the valve and movable back and forth thereacross to regulate the flow of air into the outlet ports of the valve; and wherein the pair of outer shoulders are particularly spaced such that in the neutral position the outlet ports of the valve are substantially blocked except for a relatively small opening adjacent to the respective outlet ports of the valve and an adjacent shoulder that allows constant air pressure to exist in both the outlet ports of the valve.

10. The spool type controller valve of claim 9 further including three additional shoulders formed intermediately on the spool between the outer shoulders, the three intermediate shoulders including a center shoulder movable back and forth across the inlet port of the valve for controlling the flow of inlet air into the valve, and an outlet air confining shoulder formed on each side of the center shoulder; and wherein there is a pair of inlet air spool ports formed in the spool between the center shoulder and the respective inlet air confining shoulders.