U.S. patent application number 10/230388 was filed with the patent office on 2003-04-10 for tool head attachment mechanism.
Invention is credited to Zhang, Hong Lin.
Application Number | 20030066667 10/230388 |
Document ID | / |
Family ID | 4723762 |
Filed Date | 2003-04-10 |
United States Patent
Application |
20030066667 |
Kind Code |
A1 |
Zhang, Hong Lin |
April 10, 2003 |
Tool head attachment mechanism
Abstract
A tool head attachment mechanism located within a tool body
retains a replaceable tool head in an opening of the tool body. The
mechanism includes a retaining ring including a wall having a
number of apertures therethrough. A locking ring is rotatable with
respect to the retaining ring. Ball bearings equivalent in number
to the number of apertures are retained between the locking ring
and the retaining ring. The ball bearings are sufficiently large to
extend partially, but not completely through the apertures. The
locking ring includes ramps equivalent in number to the number of
ball bearings and against each of which a respective one of the
ball bearings rolls when the locking ring is rotated with respect
to the retaining ring to thereby move the ball bearings radially to
partially project through said apertures and retain the tool head
to the tool body
Inventors: |
Zhang, Hong Lin; (Wujin
City, CN) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
700 THIRTEENTH ST. NW
SUITE 300
WASHINGTON
DC
20005-3960
US
|
Family ID: |
4723762 |
Appl. No.: |
10/230388 |
Filed: |
August 29, 2002 |
Current U.S.
Class: |
173/217 |
Current CPC
Class: |
B25F 3/00 20130101 |
Class at
Publication: |
173/217 |
International
Class: |
E21B 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 31, 2001 |
CN |
01259629.9 |
Claims
1. A tool head attachment mechanism located within a tool body and
adapted to retain a replaceable tool head in an opening of the tool
body, the mechanism comprising: a retaining ring including a wall
having an aperture therethrough, a locking ring rotatable with
respect to the retaining ring, a ball bearing retained between the
locking ring and the retaining ring, and being sized to extend
partially, but not completely through said aperture, and wherein:
the locking ring includes a ramp against which the ball bearing
rolls when the locking ring is rotated with respect to the
retaining ring to thereby move the ball bearing radially to
partially project through said aperture.
2. The mechanism of claim 1, including a plurality of said
apertures through said retaining ring wall, a plurality of said
ball bearings equivalent in number to said plurality of apertures,
each ball bearing being retained between the locking ring and the
retaining ring, and each being sized to extend partially, but not
completely through said apertures, and wherein: the locking ring
includes a plurality of said ramps equivalent in number to the
number of ball bearings and against each of which a respective one
of the ball bearings rolls when the locking ring is rotated with
respect to the retaining ring to thereby move all of the ball
bearings radially to partially project through said apertures.
3. The mechanism of claim 2, wherein the locking ring has a lever
extending radially therefrom by which the locking ring can be
rotated.
4. The mechanism of claim 1, wherein the retaining ring has a pair
of radially opposed tabs by which the retaining ring is fixed with
respect to the tool body.
5. The mechanism of claim 2, wherein one end of each ramp has a
deep recess within which one of said ball bearings can reside, and
the other end of each ramp has a shallow recess to support said one
ball bearing when it is partially projecting through one of said
apertures.
6. A tool body having an opening to receive a spigot member of a
replaceable tool head, the tool body having a tool head attachment
mechanism located in said opening, the mechanism comprising: a
retaining ring including a wall having an aperture therethrough, a
locking ring rotatable with respect to the retaining ring, a ball
bearing retained between the looking ring and the retaining ring,
and being sized to extend partially, but not completely through
said aperture, and wherein: the locking ring includes a ramp
against which the ball bearing rolls when the locking ring is
rotated with respect to the retaining ring to thereby move the ball
bearing radially to partially project through said aperture.
7. The tool body of claim 6, including a plurality of said
apertures through said retaining ring wall, a plurality of said
ball bearings equivalent in number to said plurality of apertures,
each ball bearing being retained between the locking ring and the
retaining ring and each being sized to extend partially, but not
completely through said apertures, and wherein; the locking ring
includes a plurality of said ramps equivalent in number to the
number of ball bearings and against each of which a respective one
of the ball bearings rolls when the locking ring is rotated with
respect to the retaining ring to thereby move all of the ball
bearings radially to partially project through said apertures.
8. A tool body having a replaceable tool head attached thereto, the
tool head comprising an attachment spigot member having a recess
formed therein and a tool head attachment mechanism located within
the tool body and adapted to retain the tool head in an opening of
the tool body, the attachment mechanism comprising: a retaining
ring including a wall having an aperture therethrough, a locking
ring rotatable with respect to the retaining ring, a ball bearing
retained between the locking ring and the retaining ring, and being
sized to extend partially, but not completely through said
aperture, and wherein: the locking ring includes a ramp against
which the ball bearing rolls when the locking ring is rotated with
respect to the retaining ring to thereby move the ball bearing
radially to partially project through said aperture and engage with
said recess.
9. The tool body of claim 8 comprising a plurality of said recesses
formed in an array about said spigot, and the wall of said
retaining ring having a plurality of said apertures therethrough, a
plurality of said ball bearings equivalent in number two said
apertures and retained between the locking ring and the retaining
ring and wherein the locking ring includes a plurality of said
ramps against which the respective ball bearings roll when the
locking ring is rotated with respect to the retaining ring to
thereby more all of the ball bearing radially to partially project
through said apertures and engage with respective ones of said
recesses.
10. A set including a tool body and a plurality of replaceable tool
heads for individual attachment to the tool body, the tool heads
each comprising an attachment spigot member having a recess formed
therein, and a tool head attachment mechanism located within the
tool body and adapted to retain each tool head in an opening of the
tool body, the attachment mechanism comprising: a retaining ring
including a wall having an aperture therethrough, a locking ring
rotatable with respect to the retaining ring, a ball bearing
retained between the locking ring and the retaining ring, and being
sufficiently large in diameter to extend partially, but not
completely through said aperture, and wherein: the locking ring
includes a ramp against which the ball bearing rolls when the
locking ring is rotated with respect to the retaining ring to
thereby move the ball bearing radially to partially project through
said aperture.
11. The set of claim 10, including a plurality of said apertures
through said retaining ring wall, a plurality of said ball bearings
equivalent in number to said plurality of apertures, each ball
bearing being retained between the locking ring and the retaining
ring, and each being sized to extend partially, but not completely
through said apertures, and wherein: the locking ring includes a
plurality of said ramps equivalent in number to the number of ball
bearings and against each of which a respective one of the ball
bearings rolls when the locking ring is rotated with respect to the
retaining ring to thereby move all of the ball bearings radially to
partially project through respective ones of said apertures.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a tool head attachment
mechanism. More particularly, although not exclusively, the
invention relates to a mechanism formed within a tool body and by
which a tool head such as a drill chuck mechanism, can be attached
so as to receive output torque from an electric motor housed within
the tool body.
[0002] In the art of electric power tools such as electric drills
and angle grinders for example, a recent development has been the
invention of replaceable tool heads removably attachable to a
common tool body. The common tool body houses an electric motor
from which there extends an output sprocket. The tool body usually
also has a handle and a trigger to activate the motor. An electric
power cord can extend from the base of the handle, or
alternatively, there might be provision for the attachment of a
rechargeable battery pack.
[0003] At the front end of the housing, there is an opening within
which the spindle is located. Adjacent to the opening is a pair of
radially opposed clamp levers such as those depicted at 4 in FIG.
1. These clamp levers are attached to a disk 1 located between a
pair of washers 3 and retained within the tool body behind a
retaining washer 2. The disk 1 has a pair of radially opposed tabs
to which the clamp levers 4 are attached. Once the tool head is
attached to the tool body, the clamp levers 4 are rotated about a
longitudinal axis of the tool body to thereby rotate the disk 1
whereupon inwardly projecting bayonet plates formed integrally with
the disk move behind radially extending parts of a tool head
spigot. Although this results in retaining the tool head spigot
within the opening of the tool body, the arrangement is complex and
prone to wear as there is sliding contact between adjoining
parts.
OBJECTS OF THE INVENTION
[0004] It is an object of the present invention to overcome or
substantially ameliorate at least one of the above disadvantage
and/or more generally to provide improved tool head attachment
mechanism for retaining a tool head to a tool body.
DISCLOSURE OF THE INVENTION
[0005] There is disclosed herein a tool head attachment mechanism
located within a tool body and adapted to retain a replaceable tool
head in an opening of the tool body, the mechanism comprising:
[0006] a retaining ring including a wall having an aperture
therethrough,
[0007] a locking ring rotatable with respect to the retaining
ring,
[0008] a ball bearing retained between the locking ring and the
retaining ring, and being sized to extend partially, but not
completely through said aperture, and wherein:
[0009] the locking ring includes a ramp against which the ball
bearing rolls when the locking ring is rotated with respect to the
retaining ring to thereby move the ball bearing radially to
partially project through said aperture.
[0010] Preferably the mechanism includes a plurality of said
apertures through said retaining ring wall,
[0011] a plurality of said ball bearings equivalent in number to
said plurality of apertures, each ball bearing being retained
between the locking ring and the retaining ring, and each being
sized to extend partially, but not completely through said
apertures, and wherein:
[0012] the locking ring includes a plurality of said ramps
equivalent in number to the number of ball bearings and against
each of which a respective one of the ball bearings rolls when the
locking ring is rotated with respect to the retaining ring to
thereby move all of the ball bearings radially to partially project
through said apertures.
[0013] Preferably the locking ring has a lever extending radially
therefrom by which the locking ring can be rotated.
[0014] Preferably the retaining ring has a pair of radially opposed
tabs by which the retaining ring is fixed with respect to the tool
body.
[0015] Preferably one end of each ramp has a deep recess within
which one of said ball bearings can reside, and the other end of
each ramp has a shallow recess to support said one ball bearing
when it is partially projecting through one of said apertures.
[0016] There is further disclosed here in a tool body having an
opening to receive a spigot member of a replaceable tool head, the
tool body having a tool head attachment mechanism located in said
opening, the mechanism comprising:
[0017] a retaining ring including a wall having an aperture
therethrough,
[0018] a locking ring rotatable with respect to the retaining
ring,
[0019] a ball bearing retained between the locking ring and the
retaining ring, and being sized to extend partially, but not
completely through said aperture, and wherein:
[0020] the locking ring includes a ramp against which the ball
bearing rolls when the locking ring is rotated with respect to the
retaining ring to thereby move the ball bearing radially to
partially project through said aperture.
[0021] Preferably the tool body includes a plurality of said
apertures through said retaining ring wall,
[0022] a plurality of said ball bearings equivalent in number to
said plurality of apertures, each ball bearing being retained
between the locking ring and the retaining ring and each being
sized to extend partially, but not completely through said
apertures, and wherein:
[0023] the locking ring includes a plurality of said ramps
equivalent in number to the number of ball bearings and against
each of which a respective one of the ball bearings rolls when the
locking ring is rotated with respect to the retaining ring to
thereby move all of the ball bearings radially to partially project
through said apertures.
[0024] There is further disclosed here in a tool body having a
replaceable tool head attached thereto, the tool head comprising an
attachment spigot member having a recess formed therein and a tool
head attachment mechanism located within the tool body and adapted
to retain the tool head in an opening of the tool body, the
attachment mechanism comprising:
[0025] a retaining ring including a wall having an aperture
therethrough,
[0026] a locking ring rotatable with respect to the retaining
ring,
[0027] a ball bearing retained between the locking ring and the
retaining ring, and being sized to extend partially, but not
completely through said aperture, and wherein:
[0028] the locking ring includes a ramp against which the ball
bearing rolls when the locking ring is rotated with respect to the
retaining ring to thereby move the ball bearing radially to
partially project through said aperture and engage with said
recess.
[0029] Preferably the tool body comprises a plurality of said
recesses formed in an array about said spigot, and the wall of said
retaining ring having a plurality of said apertures therethrough, a
plurality of said ball bearings equivalent in number two said
apertures and retained between the locking ring and the retaining
ring and wherein the locking ring includes a plurality of said
ramps against which the respective ball bearings roll when the
locking ring is rotated with respect to the retaining ring to
thereby move all of the ball bearing radially to partially project
through said apertures and engage with respective ones of said
recesses.
[0030] There is further disclosed here in a set including a tool
body and a plurality of replaceable tool heads for individual
attachment to the tool body, the tool heads each comprising an
attachment spigot member having a recess formed therein, and a tool
head attachment mechanism located within the tool body and adapted
to retain each tool head in an opening of the tool body, the
attachment mechanism comprising:
[0031] a retaining ring including a wall having an aperture
therethrough,
[0032] a locking ring rotatable with respect to the retaining
ring,
[0033] a ball bearing retained between the locking ring and the
retaining ring, and being sufficiently large in diameter to extend
partially, but not completely through said aperture, and
wherein:
[0034] the locking ring includes a ramp against which the ball
bearing rolls when the locking ring is rotated with respect to the
retaining ring to thereby move the ball bearing radially to
partially project through said aperture.
[0035] Preferably the attachment mechanism includes a plurality of
said apertures through said retaining ring wall,
[0036] a plurality of said ball bearings equivalent in number to
said plurality of apertures, each ball bearing being retained
between the locking ring and the retaining ring, and each being
sized to extend partially, but not completely through said
apertures, and wherein:
[0037] the locking ring includes a plurality of said ramps
equivalent in number to the number of ball bearings and against
each of which a respective one of the ball bearings rolls when the
locking ring is rotated with respect to the retaining ring to
thereby move all of the ball bearings radially to partially project
through respective ones of said apertures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] A preferred form of the present invention will now be
described by way of example with reference to the accompanying
drawings, wherein:
[0039] FIG. 1 is a schematic parts-exploded perspective
illustration of a prior art tool head attaching mechanism,
[0040] FIG. 2 is a schematic parts-exploded perspective
illustration of a tool head attaching mechanism of the preferred
embodiment,
[0041] FIG. 3 is a schematic front elevational view of the
mechanism of FIG. 2,
[0042] FIG. 4 is a schematic cross-sectional side elevational view
of the mechanism taken at F-F in FIG. 3,
[0043] FIG. 5 years a schematic side elevation of a tool body
half,
[0044] FIG. 6 is a schematic parts partially-exploded perspective
illustration of a tool body, a tool head and a rechargeable battery
pack,
[0045] FIG. 7 is a schematic perspective illustration of the tool
body, cool head and rechargeable battery pack of FIG. 6,
[0046] FIG. 8 is a schematic partial elevational view of a tool
head spigot,
[0047] FIG. 9 is another schematic partial elevational view of the
tool head spigot of FIG. 8,
[0048] FIG. 10 is a schematic front elevational view of the spigot
of FIGS. 8 and 9,
[0049] FIG. 11 is a schematic cross-sectional front elevational
view of the attachment mechanism surrounding the spigot in a locked
configuration,
[0050] FIG. 12 is a schematic cross-sectional front elevational
view of the attachment mechanism surrounding the spigot in an
unlocked configuration, and
[0051] FIG. 12 is a schematic perspective illustration of a tool
body and a number of alternative tool head attachments.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0052] In FIGS. 2 and 3 of the accompanying drawings there is
schematically depicted a tool head retaining mechanism comprising a
locking ring 7 typically fabricated from moulded plastic material.
The locking ring includes a pair of diametrically opposed levers
10, which would project outwardly from the tool body 26 (shown in
FIG. 6 for example).
[0053] The locking ring 7 includes an integrally formed back plate
14.
[0054] A retaining ring 6 having a pair of diametrically opposed
tabs 9 fits in front of the locking ring 7 at the back portion of
an opening 30 in the tool body 26. Opening 30 receives spigot 21 of
a tool head such as a drill head 11. Spigot 21, unlike some prior
art drill head spigots years of generally cylindrical shape of
constant diameter.
[0055] The retaining ring includes a wall 13 having 6 apertures 27
spaced evenly thereabout. The apertures 27 are large enough to
enable the ball bearings 8 to partially project therethrough, yet
not the whole way therethrough.
[0056] As better shown in FIG. 11, the locking ring 7 includes six
ramps 18, each having a deep recess 16 at one end and a shallow
recess 17 at the other. When the locking ring is turned in the
direction indicated by arrow B in FIG. 11 by pushing on either one
or both of the levers 10, the ball bearings 8 roll against the
respective ramp surface toward the shallow recess 17. As the
retaining ring 6 is held against rotation within the tool body 26
by virtue of tabs 9, the ball bearings move partially through the
apertures 27.
[0057] If the levers 10 are moved in the opposite direction as
indicated by arrow C in FIG. 12, the ball bearings 8 are allowed to
recede back into the deep recesses 16 as shown. In other words,
whereas the radial movement of the ball bearings is an inward
movement during the locking action, the radial movement is outward
during the unlocking action.
[0058] The spigot 21 includes a number of recesses. There might be
a continuous annular recess, a pair of recesses, or a small recess
23 corresponding to each of the ball bearings 8. when the ball
bearings 8 take on the positions as depicted in FIG. 11, the
protruding parts thereof are received within the respective recess
23 to thereby axially retain the spigot 21. The tool head is
therefore fixed to the tool body for use.
[0059] It should of course be noted that there is an electric motor
13 within the tool by the 26 having an output shaft on which there
is a drive sprocket 31. The spigot 21 includes an internal
receiving sprocket within which sprocket 31 is received to transmit
torque to the tool head.
[0060] In order to align the spigot 21 with the opening 30, there
is provided a slot 32 at the base of the opening 30 within which an
alignment tab 24 must be received into insert the spigot 21 into
the opening 30. This will ensure that if there is a plurality of
discrete apertures for each ball bearing, then those apertures will
align with the bearings for engagement. The alignment tab 24 also
ensures that the spigot cannot rotate freely within the opening 30
upon transmission of torque from the motor to the tool head.
[0061] It should be appreciated that modifications and alterations
obvious to those skilled in the art are not to be considered as
beyond the scope of the present invention. For example, there might
be only three ball bearings and associated apertures and ramps or
any other number greater or smaller than 6 as illustrated.
* * * * *