Hamilton caliber 661 (Certina 25-45) is Swiss movement from 1950s.
Functions: sweep second
Automatic movement with 17 jewels.
F = 18000 A/h
Power reserve: 42 hours
Diameter: 25.6 mm
More information:
Hamilton Automatic-a self-winding rotor watch whose oscillating weight winds the mainspring as it turns in either direction, not checked by banking stops.
Two main objectives determined its deisgn:
- Minimum amount of wear and tear, achieved by adopting very simple mechanism, and by mutually well balanced members and an efficient, patented system.
- Ease of dismmantling, so as to make cleaning and oiling operations as simple as possible.
The new Hamilton Automatic is as simple as it is ingenious; its design will delight every watchmaker.
-A miracle of accuracy satisfying the most exacting customer.
-A masculine watch in the Hamilton tradition of fine workmanship.
17 jewel movement with direct drive sweep second; simple, rugged construction.
Large barrel provides more than adequate power reserve.
Unbreakable and stainless mainspring, specially produced for the Automatic.
Brake spring prevents over-winding of the mainspring-new design, dependable and regular in operation.
Extra large balance wheel assures great accuracy.
Anti-magnetic compensating and self-adjusting hairspring.
Balance wheel pivots shock-protected.
Two-piece regulator controlled by eccentric permitting both rapid and very precise regulation. Graduations equal 20 seconds.
All parts fully interchangeable.
Rotor-type oscillating weight rotating freely round its axle; no banking stops, therefore no shocks transmitted to the movement. The pivot rests in sturdy jewels with a simple bolt arrangement and protected against breakage. Mainspring is positively wound by rotor movement in either direction, even the smallest displacement being effective.
Self-winding mechanism protected by four pratents, of remarkable simplicity. Purely mechanical in operation, it possesses no complex or delicate parts.
The high effciency of the system permits the use of a relatively light rotor, hence all parts are less subject to wear and tear.
Self-winding gears protected by a special clutch when watch is wound manually.
Repairs easily handled, as all parts of self-winding device are held fast to bridge when movement is dismantled.
Other links:
Hamilton caliber 661 watch parts
