Replace white spaces of multiple files at once

How to rename multiple files by replacing the white spaces with underscore

for ex:

293TrexFH\ \ \ GSM855007RINGB_lhb11_binary.txt
293TrexFH\ \ \ GSM855007RINGB_lhb12_binary.txt
293TrexFH\ \ \ GSM855007RINGB_lhb13_binary.txt

293TrexFH_GSM855007RINGB_lhb11_binary.txt
293TrexFH_GSM855007RINGB_lhb12_binary.txt
293TrexFH_GSM855007RINGB_lhb13_binary.txt

thanx in advance

cat input_file | tr -s ' ' '_' > output_file