Cpu and ram limiter for windows?

I got a dozen java clients ruing, and they've got a memory leak. When the memory leak happens, more ram won't be used, because theres a hard limit on the ram, however, the client will use infinite cpu. Freezing up the system. The client itself is used by a small community and there is no interest to fix the memory leaks. I need some kind of a software that will limit cpu usage between the java programs, making it so no single process can use up more than 6.7% cpu.