Hand-held machine tool

Patent metadata

Field	Value
Publication number	US-9272408-B2
Application number	US-201113297782-A
Country	US
Kind code	B2
Filing date	Nov 16, 2011
Priority date	Nov 16, 2010
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

Abstract

A hand-held machine tool is provided. The hand-held machine tool includes a striking element that is accelerated along a working axis, and a guide for the striking element. A cushioning damper limits a motion of the striking element along the working axis and has an elastic damping ring. The damping ring has grooves running on at least one face side radial to the working axis.

First claim

The invention claimed is:

1. A hand-held machine tool comprising:
a striking element accelerated along a working axis;
a guide for the striking element; and
an impact absorber that limits the motion of the striking element along the working axis, the impact absorber including an elastic damping ring;
wherein the damping ring includes first and second face sides, an inner surface extending between the first and second face sides, and an outer circumference extending between the first and second face sides;
wherein the damping ring includes a plurality of recesses that each extend axially across the outer circumference of the damping ring from the first face side to the second face side; and
wherein the plurality of recesses are formed by radial concavities opposed by radial convexities.

2. A hand-held machine tool according to claim 1 , wherein the plurality of recesses divide a contact surface into several separate segments along the circumference.

3. A hand-held machine too according to claim 1 , wherein:
the guide includes a movable sleeve that can move along the working axis; and
the movable sleeve is pre-stressed along the working axis by the elastic damping ring.

4. A hand-held machine tool according to claim 3 , wherein the movable sleeve has a stop surface for a radially projecting bead of the striking element, the stop surface oriented at least partially in the direction of the working axis.

5. A hand-held machine tool according claim 1 , wherein the plurality of recesses have a depth of between about 5% and 10% of the cross-section width of the damping ring.

6. A hand-held machine tool comprising:
a striking element accelerated along a working axis;
a guide for the striking element; and
an impact absorber that limits the motion of the striking element along the working axis, the impact absorber including an elastic damping ring;
wherein the damping ring includes first and second face sides, an inner surface extending between the first and second face sides, and an outer circumference extending between the first and second face sides;
wherein the damping ring includes a plurality of recesses that each extend radially across the first face side from the inner surface to the outer circumference; and
wherein the plurality of recesses each include a separate concavity on the first face side and a corresponding, separate convexity on the second face side of the damping ring.

7. A hand-held machine tool according to claim 6 , wherein the plurality of recesses divide a contact surface of the first face side.

8. A hand-held machine too according to claim 6 , wherein:
the guide includes a movable sleeve that can move along the working axis; and
the movable sleeve is pre-stressed along the working axis by the elastic damping ring.

9. A hand-held machine tool according to claim 8 , wherein the movable sleeve has a stop surface for a radially projecting bead of the striking element, the stop surface oriented at least partially in the direction of the working axis.

10. A hand-held machine tool according claim 6 , wherein the plurality of recesses have a depth of between about 5% and 10% of the cross-section width of the damping ring.

11. A hand-held machine tool comprising:
a striking element accelerated along a working axis;
a guide for the striking element; and
an impact absorber that limits the motion of the striking element along the working axis, the impact absorber including an elastic damping ring;
wherein the damping ring includes first and second face sides, an inner surface extending between the first and second side faces, and an outer circumference extending between the first and second face sides;
wherein the damping ring includes a plurality of recesses that each extend radially across the first face side of the damping ring from the inner surface to the outer circumference;
wherein the damping ring inner surface is devoid of any recesses; and
wherein the guide includes a movable sleeve that can move along the working axis, and the movable sleeve is pre-stressed along the working axis by the elastic damping ring.

12. A hand-held machine tool according to claim 11 , wherein the plurality of recesses divide a contact surface of the first face side.

13. A hand-held machine tool according to claim 11 , characterized in that the plurality of recesses take up a surface percentage from about 5% to 15% of a contact surface of the first face side.

14. A hand-held machine tool according claim 11 , wherein the plurality of recesses have a depth of between about 5% and 10% of the cross-section width of the damping ring.

15. A hand-held machine tool according to claim 11 , wherein the movable sleeve has a stop surface for a radially projecting bead of the striking element, the stop surface oriented at least partially in the direction of the working axis.

16. A hand-held machine tool according to claim 11 , wherein the movable sleeve is tensioned between two elastic damping rings, both of which have grooves running radially with respect to the working axis.

17. A hand-held machine tool according to claim 11 , wherein the elastic damping ring includes knobs projecting perpendicular to the working axis.

18. A hand-held machine tool comprising:
a striking element accelerated along a working axis;
a guide for the striking element; and
an impact absorber that limits the motion of the striking element along the working axis;
wherein the guide includes a movable sleeve that can move along the working axis; and
wherein the movable sleeve is tensioned between two elastic damping rings at least one of which has grooves running radially with respect to the working axis.

19. A hand-held machine tool according to claim 18 , wherein both elastic damping rings have grooves running radially with respect to the working axis.

Assignees

• Koch Olaf
• Keith Matthias
• Kraus Dieter
• Shadavakhsh Ali
• Hilti Ag

Inventors

• Koch Olaf
• Keith Matthias
• Kraus Dieter
• Shadavakhsh Ali

Classifications

• B25D2250/345

  Use of o-rings · CPC title

• B25D2217/0019

  Guide-sleeves · CPC title

• B25D2222/57

  Elastomers, e.g. rubber · CPC title

• B25D17/26 Primary

  Lubricating {(in general F16N)} · CPC title

• B25D17/06

  Hammer pistons; Anvils {; Guide-sleeves for pistons} · CPC title