Stepping motor coil core and stator assembly for a timepiece

US4795930A · kind A · utility

Assignee

• Timex Corporation · US

Inventors

• Herbert Schwartz · Wurmberg, DE
• Gerhard Stotz · Eisingen, DE

Key dates

• Filing date: Dec 3, 1987
• Grant date: Jan 3, 1989
• Expiry date: Dec 3, 2007

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02K37/16
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

In a wristwatch movement with a stepping motor with a rotor connected to drive a gear train which periodically advances the hands of the wristwatch, the stepping motor has a flat stator piece secured in a plastic movement frame. A coilcore assembly comprising a flat hook-shaped core plate having a straight core portion of uniform width with a coil inserted over the free hand of the core portion is secured to the stator so that opposite ends of the hook-shaped member overlap opposite ends the stator to complete a path for the magnetic flux. The hook-shaped coil core is placed on top of the stator during assembly and is held down by insulated clamping means such as a bridge or circuit board bolted to the frame at the time of final assembly. Preferably, the stator and coil core member are located with respect to one another by plastic studs integral with the frame extending through aligned holes in the stator and coil core. Some of the studs receive bolts which hold the clamping means to the frame.