US 10,549,357 B2Granted

Mandrel assembly for electric tool and electric tool having same

AssigneeBosch Power Tools (China) Co., Ltd.

InventorsDaniel Grolimund, Donghui Ding

Life of this patent

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Abstract

A mandrel assembly includes a mandrel, adapter, and bit coupler. The mandrel includes a shank part axially disposed in the mandrel, an adapter receiver, and a coupler receiver. An internal hole runs axially through the adapter. The coupler includes first and second axial sections, and an axial bit connection hole with a polygonal section proximate to an inner side, and a cylindrical section proximate to an opening. An outer wall of the adapter fits with an inner wall of the adapter receiver. An outer wall of the first section fits with an inner wall of the coupler receiver. An outer wall of the second coupler fits with the internal hole of the adapter. The mandrel transmits torque, via the adapter receiver and coupler receiver, to the adapter and then to a hole saw coupled to the adapter, and to the coupler and then to a bit coupled to the coupler.

Claims10

Dependent claims

A mandrel assembly for an electric tool, comprising:

a mandrel, including:
a shank part;
an adapter receiving part axially disposed on the mandrel;
and
a bit coupler receiving part axially disposed on the mandrel;
an adapter, including an internal hole that runs through the adapter axially;
and
a bit coupler, including:
a first axial coupler section;
a second axial coupler section;
and
a bit connecting hole disposed axially in the bit coupler, the bit connecting hole having a first polygonal section proximate to an inner side of the bit connecting hole and a first cylindrical section proximate to an opening of the bit connecting hole, wherein:
an outer wall of the adapter is configured to fit with an inner wall of the adapter receiving part, an outer wall of the first coupler section is configured to fit with an inner wall of the bit coupler receiving part, and, an outer wall of the second coupler section is configured to fit with the internal hole of the adapter such that the mandrel is configured to transmit torque to the adapter via the adapter receiving part, and to the bit coupler via the bit coupler receiving part;
the bit coupler receiving part further has a threaded internal hole;
and
a first part of the first coupler section is configured to fit with the threaded internal hole via a threaded connection.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/714,658Filed 25 Sep 2017
Priority: CN 2016 1 085200327 Sep 2016
Published: US 2018/0085834 A129 Mar 2018
Granted: 4 Feb 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

B23B 51/0473
Drills for trepanning: details about the connection between the driven shaft and the tubular cutting part; Arbors
B23B 31/008
Chucks ; Expansion mandrels; Adaptations thereof for remote control: with arrangements for transmitting torque
B23B 51/0003
Drills with connected cutting heads, e.g. with non-exchangeable cutting heads; Drills with a single insert extending across the rotational axis…:…
B23B 51/044
Drills for trepanning: with core holding devices