Rotary electrical tool with speed control, especially drill
US4540318A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1983 |
| Grant date | Sep 10, 1985 |
| Priority date | — |
| Expiry date | May 24, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/165
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
To provide for, selectively, control of the speed of a tool, such as a drill or boring tool coupled to an electric drill or boring machine motor, independently of the setting of a multi-speed transmission, speed of the tool is sensed by a contactless transducer (4, 7), one part of which is coupled to the chuck (1, 2) and the other to the housing (H) of the tool, to provide speed signals which incorporate the transmission ratio of the gear (G, 66). Speed control, for example under a command signal (40; 50), then will control the actual speed, regardless of the transmission setting, with the torque deliverable by the motor being controlled by the selected gear. The diameter of the drill or other tool bit is sensed also by the transducer, if coupled to the chuck jaws, to vary the output signal from the transducer as a function of chuck jaw diameter. The output signal can be selectively analyzed for frequency in a frequency evaluation stage (35), and for amplitude in an amplitude evaluation stage (34), the speed and chuck jaw spacing signals can be separated (FIG. 8) from a combined speed - chuck jaw spacing signal obtained, to provide for control of the motor as a function of material…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.