Power screwdriver
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 8, 2012
Grant Date -
Apr 29, 2010
app pub date -
Apr 21, 2008
filing date -
Apr 23, 2007
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
The invention relates to a power screwdriver (10) comprising a motor (12) and a control circuit (22) which switches the motor (12) off by means of a switch-off signal (s_Stop) when it reaches a preset desired torque value (Md_Soll), and a supporting arm (18) which absorbs energy during screwing. The invention is characterized by a voltage limiting circuit (46) that limits the motor voltage (u_Mot) occurring on the motor (12) when the energy stored in the supporting arm (18) of the motor (12), which is driven as the generator and rotates counter to the direction of drive, is dissipated, to a predetermined limiting voltage (u_Lim). The limiting voltage (u_Lim) is fixed in such a manner that the motor (12) is capable of rotating without counter-torque counter to the direction of drive when operated in the generator mode and that yet no inadmissible overvoltages occur.
First Claim
Other Claims data not available
