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US 4,209,476 AGranted
Method and apparatus for fabrication of extruded articles
AssigneeHarrel, Inc.
InventorHolton E. Harris
Life of this patent
Estimating the term…
Abstract
An improved method and apparatus is described for controlling an average dimensional characteristic of an article being extruded. This dimensional characteristic is determined from a predetermined volume of material supplied, from a measured dimensional characteristic and from a known cross sectional configuration. When the measured dimensional characteristic varies from a predetermined value, the volume of the stock material supplied is altered to restore the measured dimensional characteristic to the predetermined value.
Claims20
A method of forming an extrudate having a not readily measurable linear cross-sectional dimension and of maintaining that dimension at a predetermined, average value comprising the steps of:
- A. supplying an extrudate stock at a substantially uniform volumetric rate to an extrusion die which provides an extrudate output therefrom of predetermined cross-sectional configuration, said extrudate having a first linear cross-sectional dimension which is subject to variation over an interval of time but which is not readily measurable;
- B. monitoring the extrudate stock supply rate;
- C. measuring the length of said extrudate output over said interval of time;
- D. directly measuring a second linear cross-sectional dimension over said interval of time;
- E. indirectly determining from said measured length, from the volumetric rate, from said second linear cross-sectional dimension and from said predetermined cross-sectional configuration, the average value of said extrudate first linear cross-sectional dimension during an interval of time;
- F. determining variations between said average value and a predetermined average value of said first linear cross-sectional dimension;
- and
- G. varying the extrudate stock supply rate to said die for restoring said average determined first linear cross-sectional dimension to said predetermined average value.
5 more elements
The method of forming an extrudate having a not readily measurable linear cross-sectional dimension and of maintaining that dimension at a predetermined, average value comprising the steps of:
- A. supplying an extrudate stock in liquid or plasticized form to a metering pump;
- B. conveying an extrudate stock output from said metering pump at a volumetric supply rate to an extrudate die;
- C. supplying an output extrudate from said extrudate die to a cooling means, said extrudate having a first linear cross-sectional dimension which is subject to variation, but which is not readily measurable;
- D. monitoring the extrudate stock supply rate;
- E. measuring the length of said extrudate over said interval of time;
- F. directly measuring a second linear cross-sectional dimension over said interval of time;
- G. supplying electric signals representative of said length and said second linear cross-sectional dimension to automatic controller means for indirectly determining from said length, from said second linear cross-sectional dimension, from the supply rate of said metering pump and from said predetermined cross-sectional configuration the average value of said extrudate first linear cross-sectional dimension;
- H. determining variations between said average value and a predetermined average value;
- and
- I. varying the rate of said metering pump for varying the extrudate stock volumetric supply rate to said die to restore said average value of said first linear cross-sectional dimension to said predetermined average value.
7 more elements
An apparatus for forming an extrudate having a not readily measurable linear cross-sectional dimension and for maintaining that dimension at a predetermined, average value comprising:
- A. an extrudate die adapted to provide an extrudate output therefrom upon the application thereof of an extrudate stock material in plasticized or liquid form;
- B. metering pump means for supplying an extrudate stock to said extrudate die at a substantially constant volumetric supply rate;
- C. means for supplying said extrudate stock material in liquid or plasticized form to said metering pump means;
- D. said extrudate die having an orifice for providing an elongated extrudate output body of predetermined cross-sectional configuration, said extrudate having a first linear cross-sectional dimension which is subject to variation over an interval of time, but which is not readily measurable;
- E. means for monitoring the extrudate stock supply rate and for generating an electrical signal representative of said supply rate;
- F. means for measuring and generating an electrical signal representative of the length of said extrudate over said interval of time;
- G. means for directly measuring and generating an electrical signal representative of a second linear cross-sectional dimension over said interval of time;
- H. means for indirectly determining from said measured length, from said metering pump supply rate from said second linear cross-sectional dimension and from said predetermined cross-sectional configuration an average value of said extrudate first linear cross-sectional dimension, for determining variations between said average value and a predetermined average value of said first linear cross-sectional dimension;
- and
- I. means for varying the extrudate stock supply rate to said die for restoring said average first linear cross-sectional dimension to said predetermined average value.
7 more elements
The method of forming an extrudate having a tubular cross-sectional configuration and of maintaining a thickness of that extrudate at a predetermined average value even though that thickness is not readily measurable comprising the steps of:
- A. supplying an extrudate stock at a substantially uniform stock supply rate to an extrusion die which provides an extrudate output therefrom of tubular cross-sectional configuration, said tubular extrudate having a thickness which is subject to variation over an interval of time but which is not readily measurable;
- B. monitoring the extrudate stock supply rate;
- C. measuring the length of said tubular extrudate output over said interval of time;
- D. directly measuring the outside diameter of said tubular extrudate over said interval of time;
- E. indirectly determining from said measured length, from said measured outside diameter, from the stock supply rate and from said predetermined tubular cross-sectional configuration the average value of said extrudate thickness during an interval of time;
- F. determining variations between said average value and a predetermined average value of said thickness, and
- G. varying the extrudate stock supply rate to said die for restoring said average determined thickness of said tubular extrudate to said predetermined average value.
4 more elements
An apparatus for forming an extrudate having a not readily measurable linear cross-sectional dimension and for maintaining that dimension at a predetermined, average value comprising:
- A. an extruder means adapted to provide an extrudate output therefrom upon the application thereof of an extrudate stock material;
- B. feeder means for supplying an extrudate stock material to said extruder at a substantially constant supply rate;
- C. an extrudate die having an orifice for providing an elongated extrudate output body of predetermined cross-sectional configuration;
- D. means for supplying said extrudate output from said extruder in liquid or plasticized form to said extrudate die;
- E. said extrudate output from said extrudate die having a first linear cross-sectional dimension which is subject to variation over an interval of time, but which is not readily measurable;
- F. means for monitoring the extrudate stock supply rate and for generating an electrical signal representative of said supply rate;
- G means for measuring and generating an electrical signal representative of the length of said extrudate over said interval of time;
- H. means for directly measuring and generating an electrical signal representative of a second linear cross-sectional dimension over said interval of time;
- I. means for indirectly determing from said measured length, from said feeder means supply rate, from said second linear cross-sectional dimension and from said predetermined cross-sectional configuration an average value of said extrudate first linear cross-sectional dimension, for determining variations between said average value and a predetermined average value of said first linear cross-sectional dimension;
- and
- J. means for varying the extrudate stock supply rate to said die for restoring said average first linear croos-sectional dimension to said predetermined average value.
8 more elements
Dependencies are inferred from the claim text.