A Microcomputer-Based Quality Control Monitor for a High-Speed Cold-Heading Machine

  • K. Osman
  • R. Jones


A variety of small components, particularly fasteners, is produced by cold-heading machines at rates approaching 700 items/min. A problem commonly encountered is the incidence of cracked heads especially in pan-head fasteners with a cruciform-type drive recess. Large batches of fasteners that have defects are rejected during production on the basis of a conventional acceptance sampling scheme. These batches are subsequently 100% inspected which leads to large bottlenecks in production and considerable work in progress. The cracking is believed attributable to randomly occurring defects in the wire feedstock such as piping and surface flaws and attempts to eliminate this problem by preprocess inspection of the material have proved ineffective except in very severe cases. This paper describes the development and operating principles of a microcomputer-based quality monitor which uses information derived from the forming loads applied by the heading machine. The system identifies defective items as they are produced and provides information for automatic rejection before they reach the finished batch. The monitor uses the concept of real-time envelope evaluation, and derives information which not only identifies the production of defectives, but can also be utilized to protect the machine from accidental damage in the event of production problems.


Weld Nugget Defective Item Slave Processor Accidental Damage Permissible Deviation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    Brankamp, Hoffman, & Schewr (1980) In process control enables ghost-shift production. Wire 29, 2.Google Scholar
  2. [2]
    Manufacturers Literature Impax Series 4000: a Microprocessor Based Multi-unit Cold-header Control System.Google Scholar
  3. [3]
    Tevaarwerk, Rashed, & Broomhead (1974) Warm and cold-heading of stainless steel. ASME, paper 74-WA Prod-20.Google Scholar
  4. [4]
    Hodson, Rashed, & Broomhead (1982) A microprocessor based resistance welding monitor Welding Review, May, 29-30.Google Scholar
  5. [5]
    Osman, & Jones (1985) A flexible signal analysis system for process control in manufacturing industry Proc. 29th Int. Symp. of MIMI Barcelona, June 1985.Google Scholar

Copyright information

© Springer Science+Business Media New York 1986

Authors and Affiliations

  • K. Osman
    • 1
  • R. Jones
    • 1
    • 2
  1. 1.School of EngineeringThe PolytechnicWolverhamptonUK
  2. 2.Department of Engineering ProductionLoughborough University of TechnologyLoughborough, LeicestershireUK

Personalised recommendations