Hand-held power tool with jamming-detection sensor

• US 5,401,124 A
• Filed: 10/08/1993
• Issued: 03/28/1995
• Est. Priority Date: 04/12/1991
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hettich, Volker
• Primary Examiner(s): Bishop, Steven C.
• Application Number:
  US08/133,026
• Time in Patent Office: 536 Days
• Field of Search: 408/5, 408/6, 408/8, 408/9, 408/11, 173/176, 173/178, 173/181, 173/182, 73/862.29, 73/862.31
• US Class Current: 408/6
• CPC Class Codes: B23Q 11/04 Arrangements preventing overload of tools, e.g. restricting load
• CPC Class Codes: B25B 23/14 Arrangement of torque limiters or torque indicators in wrenches or screwdrivers couplings for transmitting rotation or clutches F16D; devices for measuring torque per se G01L
• CPC Class Codes: B25D 2211/003 Crossed drill and motor spindles
• CPC Class Codes: B25F 5/001 Gearings, speed selectors, clutches or the like specially adapted for rotary tools
• CPC Class Codes: Y10T 408/14 Responsive to condition of Tool or tool-drive
• CPC Class Codes: Y10T 408/165 to control Tool rotation

Abstract

A hand-held machine tool has a housing, a tool rotatable about a rotational axis, a motor provided with a gear unit and driving the tool in rotation about the rotational axis, the gear unit having at least one rotating part which is arranged so as not to be axially parallel to the rotational axis of the tool, a bearing supporting the rotating part of the gear unit, and a sensor arranged at the bearing so that the sensor lies in an effective region of bearing forces which are produced by a moment of occurring gyroscopic effect when the housing rotates around the rotational axis of the tool.

Claims

1. A hand-held machine tool, comprising a housing;

a tool rotatable about a rotational axis;

a motor provided with a gear unit and driving said tool in rotation about said rotational axis, said gear unit having at least one rotating part which is arranged so as not to be axially parallel to said rotational axis of said tool;

a bearing supporting said rotating part of said gear unit; and

a sensor arranged at said bearing so that said sensor lies in an effective region of bearing forces which are produced by a moment of occurring gyroscopic effect when said housing rotates around said rotational axis of said tool.

2. A hand-held machine tool as defined in claim 1, wherein said sensor is arranged on a straight line extending parallel to said rotational axis of said tool and passing through a center axis of said rotating part.

3. A hand-held machine tool as defined in claim 1, wherein said sensor is a force sensor.

4. A hand-held machine tool as defined in claim 1, wherein said sensor is a pressure sensor.

5. A hand-held machine tool as defined in claim 1, wherein said rotating part is formed as an armature of said motor.

6. A hand-held machine tool as defined in claim 1, wherein said housing, said tool and said motor with said gear unit are arranged so that the bearing forces produced by the moment of the occurring gyroscopic effect act in a different direction than bearing forces occurring in normal operation.

7. A hand-held machine tool as defined in claim 6, wherein said housing, said tool, and said motor with said gear unit are arranged so that the bearing forces produced by the moment of the occurring gyroscopic effect act transversely to the bearing forces occurring in normal operation.

8. A hand-held machine tool as defined in claim 1, wherein said gear unit has gear unit members cooperating with said rotating part and arranged so that transmission forces occurring in normal operation in said gear unit do not act in a direction of said rotational axis of said tool.

9. A hand-held machine tool as defined in claim 1;

and further comprising a control device which causes an interruption of the rotation of said tool, said sensor being arranged so as to transmit a measurement signal to said control device for causing an interruption of the rotation of said tool.

10. A hand-held machine tool as defined in claim 9, wherein said control device is formed so as to cause said motor to be shut off.

11. A hand-held machine tool as defined in claim 9;

and further comprising a safety coupling, said control device being formed so as to cause said safety coupling to be opened.