Method of correcting conicity in a tire with a feedback loop
AssigneeThe Goodyear Tire & Rubber Company
InventorsJohn Edward Fahringer, Frederick Forbes Vannan, III
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Abstract
A method for correcting the conicity value in a pneumatic tire with a feedback system based on the average conicity value as predicted by lateral forces measured during grinding is used in combination with correcting for lateral force variation, and/or radial force variation, and/or radial run-out variation characteristics of a pneumatic tire by grinding the tread surface. The correction of the conicity value is accomplished by grinding either of the shoulder regions of the tire tread.
Claims16
A method for correcting the conicity value of a tire having a circumferential tire tread with top and bottom shoulder regions and a central region therebetween, said method comprising the steps of:
- a) calculating a conicity value (CV) of said tire;
- b) comparing the absolute value (NCV) of said CV to a target conicity value (TCV) and continuing with step c) if said NCV is greater than said TCV and equal to or less than a maximum conicity value (MCV),
- c) pre-positioning (PREP) a grinder assembly with respect to said tire;
- d) grinding rubber from said selected one of said top and bottom shoulder regions, measuring lateral force while grinding, and using lateral force measurements as feedback for controlling the grinding time;
- and
- e) returning to step a).
The method of claim wherein the step c) includes the step of:
- selecting which of said top and bottom shoulder regions is to be ground based on information about whether said tire being tested is:
- a Type 1 tire in which grinding said top shoulder region for conicity causes a positive shift in said CV and grinding said bottom shoulder region causes a negative shift in said CV or,
- a Type 2 tire in which grinding said top shoulder region for conicity causes a negative shift in said CV and grinding said bottom shoulder region causes a positive shift in said CV.
The method of claim further including the step of:
- correcting said excessive lateral force variations, said excessive radial run-out, and/or said excessive radial force variations developed by said tire simultaneously with correcting for conicity.
The method of claim further including the step of:
- providing a tire force variation machine including a freely rotating loading wheel, an assembly which rotates said tire against said loading wheel to measure radial and lateral forces on said loading wheel as said tire rotates against said loading wheel, top and bottom shoulder grinders of said grinder assembly which move independently into and out of cutting engagement with said top and bottom shoulder regions of said tire tread, and a computer into which measurements and preset values are inputted for calculating and comparing operations and for controlling said top and bottom shoulder grinders.
Dependencies are inferred from the claim text.