Processes of determining torque output and controlling power impact tools using a torque transducer

• US 6,848,516 B2
• Filed: 01/07/2003
• Issued: 02/01/2005
• Est. Priority Date: 12/03/1998
• Status: Expired due to Fees

• Current Assignee: Chicago Pneumatic Tool Co. LLC (Atlas Copco AB)
• Original Assignee: Chicago Pneumatic Sales (Atlas Copco AB)
• Inventors: Giardino, David A.
• Primary Examiner(s): Smith, Scott A.
• Application Number:
  US10/338,623
• Publication Number:
  US 20030102140A1
• Time in Patent Office: 756 Days
• Field of Search: 173/176, 173/180, 173/178, 173/181, 173/2, 173/182, 173/183, 814/67, 814/70, 738/622.3, 738/622.4, 737/61
• US Class Current: 173/2
• CPC Class Codes: B25B 23/1405 for impact wrenches or screwdrivers

Abstract

An impact tool having a control system for turning off a motor at a preselected torque level.

Claims

1. An apparatus comprising:

housing;

an impact transmission mechanism within the housing;

an output shaft driven by the impact transmission mechanism;

a motor to power the transmission mechanism;

a sensor measuring a time varying face signal of the impacts; and

a control system for receiving a torque data signal from the sensor, wherein the control system turns the motor off at a preselected torque level.

2. The apparatus of claim 1, further including an input device for inputting the preselected torque level to the control system and an output device connected to the control system for providing an output torque level from the sensor.

3. The apparatus of claim 2, wherein the input device comprises a keypad.

4. The apparatus of claim 2, wherein the output device comprises a liquid crystal display.

5. The apparatus of claim 2, wherein the input device is mounted on the housing.

6. The apparatus of claim 2, wherein the input device is external to the housing.

7. The apparatus of claim 2, wherein the sensor is a ferromagnetic sensor.

8. The apparatus of claim 1, wherein the motor comprises a pneumatic motor.

9. The apparatus of claim 1, wherein the motor comprises an electric motor.

10. The apparatus of claim 1, wherein the control system includes a switch for turning on or off the motor.

11. The apparatus of claim 10, wherein the switch is chosen from the group consisting of a shut off valve, a solenoid valve, an electrical switch, a slide valve and a poppet valve.

12. The apparatus of claim 10, further including an activation trigger for turning on the switch.

13. The apparatus of claim 1, further including a power supply for supplying power to the control system.

14. The apparatus of claim 13, power supply is chosen from the group consisting of a battery, a solar cell, fuel cell, an electrical wall socket and a generator.

15. The apparatus of claim 1, wherein the sensor is a ferromagnetic sensor.