System for manufacturing springs
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Feb 12, 1991
Issued Date -
N/A
app pub date -
Nov 22, 1989
filing date -
Feb 20, 1987
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
Springs manufactured to have a desired free length nonetheless exhibit a slight difference in free length from one spring to another. This results from a change in elasticity caused by a difference in wire material or a non-uniformity in wire cross section from one lot of wire to another or within one and the same lot. A plurality of pre-manufacturing operations, respectively, produce a given number of test springs is used to determine an optimum value of a control variable which is then used in a manufacturing operation. In a pre-manufacturing operation, the difference between the desired free length and the actual free length is determined, and the amount of this difference is multiplied by the control variable to produce a feedback signal. The feedback signal determined for one spring is used to adjust the thrusting motion of a pitch tool for corresponding by adjusting the free length of a subsequent spring. Each pre-manufacturing operation is performed with a different value of the control variable. The optimum value is determined from a distribution based on the actual free lengths associated with each value thereof.
First Claim
Other Claims data not available