Power tool

Patent metadata

Field	Value
Publication number	US-9835204-B2
Application number	US-201414787189-A
Country	US
Kind code	B2
Filing date	Apr 23, 2014
Priority date	Apr 30, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A slip clutch ( 19 ) for a hand-held power tool ( 1 ) that serves to uncouple a tool socket ( 2 ) from a driving motor ( 5 ) in the event of an overload is provided. An annular running surface ( 23 ) has cams ( 24 ) projecting radially inward. The slip clutch ( 19 ) has a set of pairs consisting of a preloaded coil spring ( 28 ) and a pawl ( 29 ). The coil spring ( 28 ) presses a head ( 38 ) of the pawl ( 29 ) in the radial direction outward onto the running surface ( 23 ). The pawl ( 29 ) has a sheet-metal strip ( 34 ) whose one section is bent into a hollow prism that is annularly closed, except for a gap, in order to form the head ( 38 ). An insert ( 35 ) is placed into the gap ( 41 ) so as to fill the gap ( 41 ).

First claim

The invention claimed is:

1. A slip clutch for a hand-held power tool and serving to uncouple a tool socket from a driving motor in the event of an overload, comprising:
an annular running surface having cams projecting radially inward;
a set of preloaded coil springs and pawls combined in pairs, the coil spring pressing a head of the pawl in the radial direction outward onto the running surface, the pawl being formed as a sheet-metal strip with one section bent into a hollow prism that is annularly closed, except for a gap, in order to form the head; and
an insert placed in the gap with a frictional fit so as to fill said gap.

2. The slip clutch as recited in claim 1 wherein a width of the gap is smaller than a thickness of the sheet-metal strip.

3. The slip clutch as recited in claim 1 wherein the head has a contact surface and a support surface, the contact surface being in contact with the running surface and a respective coil spring of the set of coil springs associated in pairs with a respective pawl of the pawls being in contact with the support surface, the contact surface and the support surface being formed by the sheet-metal strip, and one end of the support surface facing away from the contact surface being in contact with the insert.

4. The slip clutch as recited in claim 3 wherein the end is clamped under pre-tensioning against the insert.

5. The slip clutch as recited in claim 1 wherein the sheet-metal strip is bent to form a cylindrical bearing head, a flat lever arm and the prismatic head.

6. The slip clutch as recited in claim 5 wherein the insert is held with a positive fit in the cylindrical bearing head.

7. The slip clutch as recited in claim 5 wherein the cylindrical bearing head is hollow.

8. The slip clutch as recited in claim 1 wherein the insert is made of plastic or titanium.

9. The slip clutch as recited in claim 1 wherein the head has an embossed projection onto which the coil spring is placed.

Assignees

• Hilti Ag

Inventors

• Granacher Thomas

Classifications

• F16D7/04

  of the ratchet type (similar gearings based on repeated accumulation and delivery of inertia-energy F16H33/08; {overload clutches of the ratchet type F16D43/202}) · CPC title

• F16D7/10

  moving radially between engagement and disengagement · CPC title

• F16D7/048 Primary

  with parts moving radially between engagement and disengagement (F16D7/10 takes precedence) · CPC title

• F16D41/12

  with hinged pawl co-operating with teeth, cogs, or the like (F16D41/02, F16D41/24 take precedence) · CPC title

• F16D43/2028

  with at least one part moving radially between engagement and disengagement (F16D43/208 takes precedence) · CPC title