Can anyone please ID this adjustable spanner please ? The only markings are 62 and D R Patent

Harry Scheffer Prussia, Germany, patented quick adjust wrench. Patent 741,841, patented October 20, 1903. Manufactured by Remsheid Haddenbach Germany. Mine is 10 inches long, they can be found in different sizes but I'm not sure how many different sizes were offered.

Thanks for your reply

Simple design, interesting. The harder you "wrench" the tighter it grips. Have you tried it ?
Joe B