The Door into Summer

When Dan Davis is crossed in love and stabbed in the back by his business associates, the immediate future doesn't look too bright for him and Pete, his independent-minded tom cat. Suddenly, the lure of suspended animation, the Long Sleep, becomes irresistible and Dan wakes up thirty years later in the twenty-first century. He discovers that the robot household appliances he invented, far from having been stolen from him, have, mysteriously, been patented in his name. There's only one thing for it. Dan has to, somehow, travel back in time to investigate...