Speed detector for sewing machines
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Mar 13, 1984
Grant Date -
N/A
app pub date -
Jul 30, 1981
filing date -
Jul 31, 1980
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A speed detector comprises a rotary shaft for rotation with a sewing machine, a ring-shaped permanent magnet uniformly magnetized in a direction parallel to the axis of the rotary shaft, at least one ring-shaped, internally toothed ferromagnetic member or stator and an externally toothed ferromagnetic circular member or rotor which is secured to the rotary shaft inside the stator to form a varying air gap between the opposing teeth. The permanent magnet and the two ferromagnetic members are disposed to form a closed loop magnetic circuit in which a ring-shaped coil is disposed. The air gap and hence the reluctance of the magnetic circuit changes periodically with the revolution of the rotary shaft so that a voltage is generated in the coil which varies at a frequency proportional to the operational speed of the sewing machine.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully