Hand-held machine tool comprising a drive motor

Patent metadata

Field	Value
Publication number	US-11707828-B2
Application number	US-202117323162-A
Country	US
Kind code	B2
Filing date	May 18, 2021
Priority date	Apr 11, 2016
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

A hand-held machine tool, in particular a sanding machine, including a rod-type handle element for the user to grip and a processing head which is moveably mounted on the handle element by means of a joint assembly. The processing head has an electric drive motor for driving a tool holder provided for holding a processing tool and a speed-reducing gearbox between the drive motor and the tool holder, the gearbox being designed to achieve a reduction in speed of an output of the drive motor relative to a speed of the tool holder. The drive motor is a brushless motor and a power supply system for the drive motor is arranged at a distance from the drive motor on the handle element, the power supply system being connected to the drive motor by means of a cable arrangement.

First claim

The invention claimed is:

1. A hand-held sanding machine comprising:
a rod-shaped handle element for a user to grip;
a joint assembly disposed at a distal end of the rod-shaped handle element;
a sanding head movably mounted on the handle element via the joint assembly, the sanding head comprising a tool holder, a sanding plate attached to the tool holder and a sanding disk or a sanding sheet fastened to the sanding plate;
a brushless electric drive motor supported on the sanding head for driving the tool holder;
a speed-reducing gear unit between the drive motor and the tool holder, the gear unit being configured to achieve a reduction in speed of an output of the drive motor relative to a speed of the tool holder;
a power supply system for the drive motor arranged at a distance from the drive motor on the handle element; and
a line arrangement connecting the power supply system to the drive motor,
wherein the power supply system is arranged on or directly alongside a handle region for gripping the handle element by an operator, and
wherein the power supply system is arranged in a housing and has an electronic commutator, and
wherein the distance between the sanding head and the power supply system is at least three times a diameter of the sanding head.

2. The hand-held sanding machine according to claim 1 , wherein the gear unit comprises a gear unit or an eccentric gear unit generating a hypercycloid motion of the tool holder.

3. The hand-held sanding machine according to claim 1 , wherein the line arrangement, for each phase of an exciter coil arrangement of the drive motor, comprises in each case a conductor or exclusively one conductor.

4. The hand-held sanding machine according to claim 3 , wherein the conductor of the line arrangement for supplying the phases of the drive motor individually or as a whole are arranged in at least one electromagnetically-screening screening device.

5. The hand-held sanding machine according to claim 1 , wherein the line arrangement comprises conductors provided exclusively for supplying power to the drive motor and/or between the drive motor and the power supply system no data line exclusively for data transmission and not for supplying power to the drive motor runs to a sensor arranged on the drive motor.

6. The hand-held sanding machine according to claim 1 , wherein the power supply system and the drive motor in each case have at least one fan, and/or, on a motor shaft of the drive motor, a fan propeller is arranged in a torsionally-rigid manner.

7. The hand-held sanding machine according to claim 1 , wherein the distance between the sanding head and the power supply system is at least two or three times a length of the power supply system or its housing and/or wherein it has at least one energy storage device connection for an electrical energy storage device.

8. The hand-held sanding machine according to claim 1 , wherein an axis of rotation of the output of the drive motor and an axis of rotation of the tool holder are parallel to one another or are at an angle of a maximum of 30° to one another and/or wherein the drive motor does not protrude beyond a machining surface of the sanding plate and/or beyond a cover of the sanding head for the sanding plate transversally to the axis of rotation of the tool holder.

9. The hand-held sanding machine according to claim 1 , wherein the drive motor is arranged outside a center of gravity or center of the sanding head and/or alongside a pivot axis of the joint assembly on the sanding head.

10. The hand-held sanding machine according to claim 1 , wherein the drive motor is arranged in a motor housing, on which at least one protection body is provided for damping a mechanical shock impacting on the motor housing and/or at least one hoop guard can be arranged to protect the motor housing from mechanical loading.

11. The hand-held sanding machine according to claim 10 , wherein the protection body is arranged on an area of the motor housing facing away from the sanding head and/or has a circular design and/or comprises an elastic material, and/or is a plug-in component detachable from the motor housing, which can be plugged into a socket opening of the motor housing.

12. The hand-held sanding machine according to claim 10 , wherein the drive motor is arranged in an electromagnetically screening housing formed by the motor housing or arranged in the motor housing and/or an air routing body arranged in the motor housing for guiding cooling air through the drive motor or past the drive motor and/or connected with a screening electromagnetically screening one of the conductors.

13. The hand-held sanding machine according to claim 1 , wherein the power supply system and the sanding head are arranged on opposing end regions of the handle element.

14. The hand-held sanding machine according to claim 1 , wherein the line arrangement connecting the drive motor with the power supply system is arranged along the handle element.

15. The hand-held sanding machine according to claim 14 , wherein the line arrangement comprises conductors exclusively provided for supplying power to the drive motor.

16. The hand-held sanding machine according to claim 1 , wherein, between the power supply system and the drive motor, no data line is provided or runs that serves exclusively for data transmission and not for supplying power to the drive motor.

17. The hand-held sanding machine according to claim 1 , further comprising a connection device for connection to an electrical energy supply network.

18. The hand-held sanding machine according to claim 17 , wherein the connection device is configured for connection to an alternating voltage network.

19. The hand-held sanding machine according to claim 18 , wherein, during a conditioning of a supply voltage from the energy supply network, the power supply system converts an alternating voltage into an intermediate circuit direct voltage.

20. The hand-held sanding machine according to claim 1 , further comprising a switch provided on the housing for switching on the drive motor.

21. A hand-held machine tool comprising:
a rod-shaped handle element for a user to grip;
a joint assembly disposed at a distal end of the rod-shaped handle element;
a machining head movably mounted on the handle element via the joint assembly, the machining head comprising a machining tool, a tool holder holding the machining tool, a cover defining an area surrounding the machining tool and a suction connection provided on the cover through which dust, dirt or chips can be extracted from the area surrounding the machining tool;
a suction flow channel extending from the suction connection of the machining head along the rod-shaped handle element to a proximal end of the rod-shaped handle element opposite the machining head;
a brushless electric drive motor supported on the machining head for driving the tool holder;
a speed-reducing gear unit between the drive motor and the tool holder, the gear unit being configured to achieve a reduction in speed of an output of the drive motor relative to a speed of the tool holder;
a power supply system for the drive motor arranged at a distance from the drive motor on the handle element; and
a line arrangement connecting the power supply system to the drive motor,
wherein the power supply system is arranged on or directly alongside a handle region for gripping the handle element by an operator, and
wherein the power supply system is arranged in a housing and has an electron

Assignees

• Festool Gmbh

Inventors

• Walker Nico

Classifications

• B25F5/001 Primary

  Gearings, speed selectors, clutches or the like specially adapted for rotary tools · CPC title

• B25F5/00 Primary

  Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for · CPC title

• B25F5/008

  Cooling means · CPC title

• B25F5/02

  Construction of casings, bodies or handles {(B25F5/006, B25F5/008 take precedence)} · CPC title

• B24B7/184 Primary

  pole sanders · CPC title