I am no Windows expert, and untested, but combining some sources gets me:
To read Mac OS Extended (aka HFS+) disks on Windows, according to Wikipedia:
HFSExplorer is an application for viewing and extracting files from an HFS+ volume (Mac OS Extended) or an HFSX volume (Mac OS Extended, Case-sensitive) located either on a physical disk, on a
.dmg disk image, or in a raw file system dump.
It seems that an Ubuntu Live CD also has support for HFS+.
Once you have access to the drive you will see a structure of folders. This screenshot from the HFSExplorer web site shows such Time Machine backup folder:
Backups.backupd/<computer name>/Latest should get you your latest backup. Your documents will be in the sub folder
<hard disk name>/Users/<user name>.
And even though there's no need to make any changes to the disk: remember to always use something "Safely remove hardware" before unplugging the disk from Windows (just like you would "eject" it on a Mac).