- Patent Title: Cordless impact tool with brushless, sensorless, motor and drive
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Application No.: US15903426Application Date: 2018-02-23
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Publication No.: US10987784B2Publication Date: 2021-04-27
- Inventor: Warren A. Seith
- Applicant: Ingersoll-Rand Industrial U.S., Inc.
- Applicant Address: US NC Davidson
- Assignee: Ingersoll-Rand Industrial U.S., Inc.
- Current Assignee: Ingersoll-Rand Industrial U.S., Inc.
- Current Assignee Address: US NC Davidson
- Agency: Advent, LLP
- Agent Kevin E. West
- Main IPC: B25B19/00
- IPC: B25B19/00 ; B25B21/02 ; B25B21/00 ; H02P6/182 ; H02P6/21

Abstract:
An impact tool of the present disclosure provides an impact mechanism having a hammer and an anvil, the hammer being rotatable about a first axis and to periodically impact the anvil to drive rotation of the anvil about the first axis. The electric motor includes a plurality of pole pairs of windings and a rotor that is rotatable with respect to consecutively energized pole pairs of windings. No encoder or sensor is electronically coupled to the electric motor to detect a position of at least one magnet attached to the rotor with respect to at least one pole pair when the rotor is in a stopped condition. When the rotor is in the stopped condition, the motor controller energizes the at least one pole pair to initiate rotation and detect a back EMF generated by movement of the rotor without a sensor or encoder to indicate the predetermined location of the at least one magnet attached to the rotor with respect to the at least one pole pair.
Public/Granted literature
- US20190262977A1 Cordless Impact Tool With Brushless, Sensorless, Motor & Drive Public/Granted day:2019-08-29
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