Double Hung Window Coil Balances

I have double hung windows with with 2 coils to each constant force spring housing. The top coil has stamped on it 6.5 PAT5 8. The bottom coil has a 3 stamped on it. Both coils measure right at 0.496 inches diameter using a caliper. The top coil thickness is @ 0.181 inches. The bottom coil is @ 0.158 inches. The plastic housing/compartment for the springs also broke.

The shoe on the inside had Patent then under it 4.610.108

I have 3 windows that I would like to replace the double coil constant force springs with shoes. Your help in this matter is greatly appreciated.

James

Hello Tom, I would like to move forward with ordering your recommendations:

6 of the S160-6

6 of the 15-111.

I also need the plastic cases for each.

Also please note that each side of the windows has two springs or double springs in each plastic holder.

Please give me instructions on how to order these.

Thanks,

James