C172 TURNED DOWNWIND THEN HIT BY SECOND C172 ENTERING PATTERN.

Narrative

HAD JUST TURNED DOWNWIND AT 1000 FT AT 80 MPH WHEN A CESSNA SUDDENLY APPEARED ON MY L CLOSING RAPIDLY AT ABOUT 100 FT DISTANCE. I TOOK EVASIVE ACTION ROLLING HARD R AND DIVING. THE PLANES COLLIDED DAMAGING THE OTHER ACFT'S R ELEVATOR AND MINOR DAMAGE TO MY ACFT'S L DISTAL FRONT WING AND MINIMAL SCOPE ON THE L STRUT AND FRONT EDGE OF WING ABOVE STRUT. BOTH PLANES LANDED WITHOUT DIFFICULTY. BOTH PLTS WERE SOLO AND NEITHER WAS HURT. THERE WAS NO RADIO WARNING OF APCHING ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATES HE FILED RPTS WITH BOTH FAA AND NTSB AND HAS HEARD FROM NEITHER ORGANIZATION. RPTR RECENTLY CALLED NTSB FOR A COPY OF THEIR RPT AND COPY OF THE TWR TRANSCRIPT. THEY WILL BE AVAILABLE IN A FEW WKS. RPTR INDICATED THAT THE TWR NORMALLY WILL GIVE TA'S TO ACFT IN THE PATTERN IF ANOTHER ACFT IS ENTERING THE PATTERN. NO ADVISORY OF ANY KIND WAS ISSUED. RPTR FEELS THAT THE OTHER ACFT WAS IN THE WRONG PLACE AND TWR NOT AWARE OF HIS POS. RPTR ACFT HAS BEEN REPAIRED AND IS FLYING AGAIN.