Hand-held power tool

Patent metadata

Field	Value
Publication number	US-11697198-B2
Application number	US-201716469543-A
Country	US
Kind code	B2
Filing date	Dec 6, 2017
Priority date	Dec 15, 2016
Publication date	Jul 11, 2023
Grant date	Jul 11, 2023

Abstract

A hand-held power tool includes a tool holder for holding a chiseling tool, a machine housing (16), and a striking mechanism (12) including a striking body (22) moved on a longitudinal axis (5) for exerting strikes on the tool in an impacting direction. A damper (23) is used for stopping the striking body (22). The damper (23) includes a ring made up of multiple elastic beads situated along a circumferential direction around the longitudinal axis (5).

First claim

What is claimed is:

1. A hand-held power tool comprising:
a tool holder for holding a chiseling tool;
a guide tube having an interior;
a striking mechanism including a striking body moved on a longitudinal axis for exerting strikes on the tool in an impacting direction, the striking body moving in the interior of the guide tube;
a damper contacting the striker body to stop the striking body, the damper including a ring made up of a plurality of elastic beads situated circumferentially around the longitudinal axis, the ring made up of the plurality of beads being located within the interior of guide tube, the plurality of beads including identical spherical larger beads and identical spherical smaller beads directly joined to each other, the larger beads being larger than the smaller beads.

2. The hand-held power tool as recited in claim 1 wherein the beads each include a first front side pointing in the impacting direction and a second front side pointing against the impacting direction, at least one of the first and second front sides being inclined in relation to a plane perpendicular to the longitudinal axis.

3. The hand-held power tool as recited in claim 2 wherein the one front side is inclined and ellipsoidal.

4. The hand-held power tool as recited in claim 2 wherein the one front side is inclined and convexly curved.

5. The hand-held power tool as recited in claim 2 wherein centers of gravity of circumferentially adjacent beads are situated at a distance and the one front side is inclined and has a radius of curvature along the circumferential direction around the longitudinal axis, the radius of curvature being between 25% and 100% of the distance.

6. The hand-held power tool as recited in claim 2 wherein a center of the first front side and a second center of the second front side are located on an axis parallel to the longitudinal axis.

7. The hand-held power tool as recited in claim 1 further comprising a machine housing, wherein, under a force effect of the striking body on the damper, a contact surface of one of the first and second front sides rests indirectly or directly on the machine housing and an other contact surface of the other of the first and second front sides rests indirectly or directly on the striking body, the contact surface or the other contact surface increasing with increasing force effect.

8. The hand-held power tool as recited in claim 7 wherein the damper compresses by a spring deflection under the force effect and the contact surface and the other contact surface increases at least proportionally to the spring deflection and is concavely curved.

9. The hand-held power tool as recited in claim 1 wherein, in the case of at least one of the beads, and with regard to cross sections in all planes containing the longitudinal axis, one cross section is maximal and one cross section is minimal, the surface area of the minimal cross section being between 20% and 50% of the surface area of the maximal cross section.

10. The hand-held power tool as recited in claim 1 wherein, in the case of at least one of the beads, with regard to cross sections in all planes containing the longitudinal axis, one cross section is maximal, and the other cross sections are located within the maximal cross section in a cylindrical projection.

11. The hand-held power tool as recited in claim 1 wherein, in the case of at least one of the beads, with regard to cross sections in all planes containing the longitudinal axis, one cross section is maximal and one cross section is minimal, and in a cylindrical projection of the minimal cross section on the maximal cross section, the minimal cross section is located within the maximal cross section and a ring-shaped closed section of the maximal cross section is located outside the minimal cross section.

12. The hand-held power tool as recited in claim 1 further comprising a machine housing, the damper including a stationary seat in the machine housing, the ring resting with one front side along the longitudinal axis on the stationary seat.

13. The hand-held power tool as recited in claim 1 wherein the damper further includes a seat fixed in the guide tube, the ring resting with a front end side of the ring on the seat against the impacting direction.

14. The hand-held power tool as recited in claim 13 wherein the damper further includes a protective disk movable with respect to the guide tube, the protective disk situated between a rear end side of the ring and an anvil.

15. The hand-held power tool as recited in claim 14 wherein the protective disk overlaps in a radial direction with a shoulder of the striking body.

16. The hand-held power tool as recited in claim 15 wherein the protective disk does not overlap in the radial direction with an impacting surface of the striking body.

17. The hand-held power tool as recited in claim 1 wherein the damper only overlaps in a radial direction with a ring-shaped shoulder of the striking body.

18. The hand-held power tool as recited in claim 17 wherein an internal diameter of the damper is larger than a diameter of the striking body at an impacting surface and smaller than a diameter of the striking body at the ring-shaped shoulder.

19. The hand-held power tool as recited in claim 1 wherein the damper includes a seat and a protective disk, the ring being between the protective disk and the seat.

20. The hand-held power tool as recited in claim 19 wherein the seat and the protective disk are located within the interior of guide tube.

Assignees

• Hilti Ag
• Hilti Aktiengeselleschaft

Inventors

• Mayr Florian
• Steingruber Adrian
• Marsiglia Katharina
• Nübel Vera

Classifications

• B25D2217/0073

  Arrangements for damping of the reaction force · CPC title

• B25D2222/57

  Elastomers, e.g. rubber · CPC title

• B25D16/00

  Portable percussive machines with superimposed rotation {, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit (combined percussion and rotary drilling adapted for earth drilling E21B6/00)} · CPC title

• B25D2250/181

  Pneumatic tool components · CPC title

• B25D2211/068

  Crank-actuated impulse-driving mechanisms · CPC title