Hand-held power tool

Abstract

A hand-held power tool has a main element; a main handle fastened to the main element, the main handle being supported such that the main handle is movable relative to the main element, the main element including a tool fitting that defines a tool axis and the center of gravity that defines a normal direction oriented perpendicular to the tool axis and pointing toward the center of gravity, the main element being moved out of a stationary position toward the main handle so that a portion of at least 10% by weight of the main element is guided with a movement component in the normal direction along a trajectory.

Description

BACKGROUND OF THE INVENTION [0001] The present invention is directed to a hand-held power tool. [0002] Rotary hammers are made known in publication DE 38 39 207 A1, in the case of which a rear main handle is supported such that it is movable relative to the rest of the rotary hammer. As a result of the movable support, combined with a spring element, vibration damping of the main handle is achieved, since oscillatory motions travelling from the tool toward the main handle are largely absorbed. SUMMARY OF THE INVENTION [0003] Accordingly, it is an object of the present invention to provide a hand-held power tool which is a further improvement of the existing tools. [0004] The present invention is directed to a hand-held power tool, in particular a rotary hammer and / or chisel hammer, composed of a main element and a main handle fastened to the main element, wherein the main handle is supported such that it is movable relative to the main element, and the main element includes a tool f...

AI Technical Summary

Benefits of technology

[0005] It is provided in accordance with the present invention that, when the main element is moved from a stationary position toward the stationary handle, a portion of at least 10 percent by weight of the main element is guided in a trajectory with a movement component in the normal direction. As a result, not only can vibrations that induce motions of the main element from the tool toward the main handle be damped, but so can vibrations that induce a movement component of the main element in the normal direction or around the center of gravity. As a result, the overall vibration damping of the main handle is improved considerably.

[0009] The “stationary position” can be understood to be a position of the main handle relative to the main element in which no external forces are applied to the main handle, e.g., by an operator. In the stationary position, the main handle is typically pressed against a stop by a spring element. The portion of the main element guided in the normal direction along a trajectory with a movement component is a significant portion of the main element. A portion such as this comprises 10 percent by weight, and particularly at least 35 percent by weight of the main element, a portion of more than 50 percent by weight of the main element resulting in a particularly good vibration damping of the main handle.

[0011] Good damping can be obtained in a particularly simple, economical manner when the main handle is capable of swiveling around a single pivot axis relative to the main element, the pivot axis being located in front of a—possibly another—main element portion of at least 10 percent by weight of the main element. The directions “front” and “back” are defined relative to the tool axis, the tool fitting being located at the front of the hand-held power tool.

[0012] A particularly stable movement guidance of the handle can be obtained when the main handle is capable of being swiveled relative to the main element around at least two pivot axes. The main handle is advantageously capable of being swiveled via two rotating elements capable of being swiveled around the pivot axes and moved relative to the main handle, so that the main handle is capable of being swiveled relative to the main element, in particular around four pivot axes. Via the selection of the orientation and length of the two rotating elements relative to each other, a high degree of flexibility can be obtained in terms of adjusting the trajectory of the main element relative to the main handle.

[0015] A simple design for fastening the main handle while ensuring a high level of flexibility in terms of selection of the trajectory can be achieved when the rotating elements are supported in individual supports in a pivoting manner at their ends facing away from the main handle, and a straight line extending through the support forms an angle >45° with the tool axis. In particular, this line is located substantially perpendicular to the tool axis.

[0017] A high damping effect can be achieved when—with the main handle remaining stationary—the main element makes a rotational movement of its own around a joint-free axis of rotation when it moves from a stationary position and approaches the main handle. This axis of rotation does not pass through a pivotal point. Instead, it passes a site that is favorable for vibration damping, e.g., through a motor housing or entirely outside of the hand-held power tool.

Problems solved by technology

As a result, not only can vibrations that induce motions of the main element from the tool toward the main handle be damped, but so can vibrations that induce a movement component of the main element in the normal direction or around the center of gravity.

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