Inventors:
Phillip J. Smith - Belmont MA
George A. Smith - Littleton MA
Assignee:
Factory Mutual Research Corporation - Norwood MA
International Classification:
G01N 308
Abstract:
A single-ply roof cover fatigue tester includes an adjustable platen to which a roof cover sample is attached. Movement of the platen relative to a support frame adjusts the angle at which a tension force is applied to the sample by fluid pressure cylinders. The platen is long enough to accommodate the roof cover sample and three associated fasteners in a straight line at a spacing commonly used in actual roof cover installations. A control system controls the flow of pressure fluid to fluid pressure cylinders on opposite sides of the sample to alternately increase the tension on one side and then the other, while maintaining a minimum tension on the opposite side. A counter is provided to indicate the number of times the increasing tension alternates from one side to the other.