Looking for hardware for my windows

Thanks for writing in. First, I'll clarify on a few points. The broken piece in your photos is called a pivot shoe. The pivot shoe is, as you noted, what holds the pivot bars that connect to the window sash; this is the assembly that allows the window to tilt inward. The pivot shoe also connects to the coil springs further up in the window track. The coil springs are what enable the opening and closing of the window. Now, if your coil springs haven't snapped, you may be able to re-use them. Otherwise, you will need to replace them as well. 

Your pivot shoe looks like our 15-192. This pivot shoe is compatible with our Series 170 and Series 171 coil springs. The Series 171 is used if you need more than one coil spring on each side of the window sash. It stacks atop the Series 170, and has a longer tongue to reach the pivot shoe. Let us know if you have any questions.