Insurance coverage for thousands of asbestos claims against Hennessy Industries, as Ammco Tools’ successor, turned on the number of “occurrences” under umbrella policies issued by Continental Casualty Co. and Northbrook Excess & Surplus Insurance Co.Ammco manufactured machinery — including brake shoe grinders and lathes — that were allegedly defective when used on asbestos-containing brake shoes because they generated clouds of asbestos dust.A Cook County judge agreed with Continental and …