Method of manufacturing a timepiece wheel
AssigneeSeiko Epson Corporation
InventorToshimasa Ikegami
Life of this patent
Estimating the term…
Abstract
A method for manufacturing a timepiece wheel having a bearing portion integrally formed with a pinion and gear wheel. A strip of material is compressed to simultaneously form a thin gear, a pinion and bearing surfaces. The formed gear is then sheared from the remainder of the strip formed of a metal.
Claims11
A method for forming a timepiece wheel having a gear wheel with gear teeth formed about the circumference thereof, the gear wheel being integrally formed with a pinion comprising the steps of;
- inserting a strip of material into a die;
- applying a compressive load to one portion of the strip member at both the front and back surfaces, the compressive load being applied to a portion having an area greater than that of the gear wheel to form a thinned portion;
- pushing a portion of the material of the thinned portion centrally to form a pinion portion and bearing portion projecting from the plane of the thinned portion of the strip;
- and
- shearing the thin portion from the strip of material.
A method for forming a wheel and pinion for a timepiece integrally formed as a unitary structure having a shaft portion, a gear wheel extending therefrom, gear teeth formed about the circumference of the gear wheel and a pinion supported about the shaft portion, a concave bearing surface being formed at the top of the shaft portion and a concave bearing surface being formed at the bottom of the shaft comprising the steps of:
- inserting a strip of material into a die;
- applying a compressive load to both the front and back surfaces of the strip at a portion of the strip having an area larger than that of the diameter of a circle formed by the gear teeth to form a thin material portion;
- forming a shaft and pinion from the greater part of material formerly contained within the thin portion during the application of the compressive load;
- forming a first concave portion at one end of the shaft;
- forming a second concave portion at an opposed end of the shaft.
A method for producing a timepiece wheel having a gear wheel integrally formed with a pinion, a shaft extending from the gear wheel having a distal end which ends in a projecting pivot, comprising the steps of:
- placing a strip of material within a die, the lower die being formed with a cylindrical portion forming the projecting pivot and having an ejector pin at the end of the projecting pivot;
- providing a compressive load at both the front and back of the strip of material to form a thinned region;
- forcing the material from the thinned region within the die to form the projecting pivot;
- ejecting the material from the die at least using the ejector pin;
- controlling the position of the ejector pin during the application of the compressive force to reduce the production of a burr;
- and
- shearing the compressed section from the strip of material.
Dependencies are inferred from the claim text.