Yes there are several machines - I used to have 3 of them made by AYR. I adapted for video/audio out and fed that into a vhs recorder. Used for recording subtitles onto video for deaf people.
My best recommendation would be to get a Hauppauge cord for a pc that should work.
or you could use the BBC teletext adaptor and a BBC micro to capture.
There has also been various attempts to get data from VHS video tapes to recover teletext signals - maybe worth looking at that. (try
www.glasstty.com).