Note: Descriptions are shown in the official language in which they were submitted.
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AN EXTRACTOR TOOL FOR BEARINGS, BUSHI~GS AND THE LIKE
BACKGROUND OF THE INVENTION
This invention relates to an extractor tool for
bearings, bushings and the like and is particularly but
not exclusively designed for use with a ~pherical bushing
(uni-ball) from the outward shaft of the rotor drive
gearbox of a combine.
~ At present, one has to remove gearboxes before
removing spherical bushing (uni-ball~ with 3 slide hammer
puller. When this method is used and i6 unsuccessful in
removing spherical bushing (uni-ball), 90~ of dealerships
use a cut~ing torch, therefore running the risk of damag-
ing the output shaft, plus overheating of this shaft
could cause shaft and seal failure. This method takes
approximately 8 - 9 hours. If the gearboxes are left in
the combine, the slide hammer puller cannot be used
because there is no room to work with it. Some dealer-
ships move the rotors forward enough or completely remove
and then use a cutting torch, running the rlsk of inter-
nal ~ire in the combine and probable damage to output
shaft and gearbox seal. Approximate time 3 1/2 - 4
hours. If ~eal ailure does exist, gearboxes have to be
pulled from the combine for seal replacement.
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Various designs of puller devices have been
located in a search as follows:
U.S. Patent 2847752 discloses a valve lifter
extractor but this is unsatisfactory for the purpose for
which the present invention is concerned for the follow-
ing reasons:
1. Relies on hand pull power which does not pro-
vide necessary force to extract the spherical bushing.
2. ~ Cannot be used in confined area.
3. Does not provide depth required; therefore,
would not grip the bushing.
4. Does not provide backing against gear box to
relieve the stress.
U.S. Patent 2671263 discloses an extractor tool
for bearings and bushings, but this is unsatisfactory for
the following reasons:
1. Relies on barbed ends for friction grip on the
hard steel surface, inside of the spherical bushing,
which would not provide the necessary grip for extrac
tion.
2. Uses a finger ~urn head for the expansion pres-
sure which would not provide sufficient outer force for
grip to pull out the spherical bushing.
3. Rotating handles would be too short in confined
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areas to cxert necessary force or torque for removal of a
spherical bushing.
4. Only hand pressure can be used to keep the
whole unit from rotating while attempting to remove a
spherical bushing. 5. All parts must b~ machined thus
creating greater manufacturing cost.
U.S. Patent 1496134 discloses a tool for
extracting expansion bolts, but this is unsatisfactory
for t~e following reasons:
1. Depends on hand pull which would not provide
the necessary force to remove a spherical bushing.
2. Extraction tongs do not provide the necessary
grip for extraction force.
3. Cannot be used in limited space area.
4. Gear box needs to be tightly secured because
there is no backing force applied against the gear box.
U.S. Patent 1363934 discloses a journal box or
flue puller, but this is unsatisfactory for the following
reasons:
1. Relies on hand pull or chain to exert pulling
force which would not be possible in a confined area.
2. Depends on a rat-tail grip pattern on the
extracting portion of the puller which would not provide
the necessary grip for extraction.
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3. Difficult to exert pulling force when having to
ensure the ~edge pressure is secure at the start.
U.S. Patent 3052973 discloses a tool for remov-
ing bushings, but this is unsatisfactory for the follow-
ing reasons: ;
1. The barbed grip end of the extraction unit
would not be able to provide sufficient grip friction to
remove hard steel spherical bushings.
2, Use of a fixed rotating handle of ~ufficient
length to provide torque necessary for removal would not
be operable in a confined area.
3. The stand assembly makes it impossible to man-
oeuver in confined areas when gear box is not removed
from the implement.
4. The coil spring retainex would limit the depth
~ize of spherical bushings that could be removed.
5. The nut to expand the barbed unit is a hand
turn which would not provide enough torque to provide
expansion force necessary for removal.
6. All parts must be especially machined making
the cost expensive.
7. The unit that the bushing is being removed from
muæt be ~upported up for the tool.
U.S. Patent 2290427 discloses a bearing puller,
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but this is unsatisfactory for the following reasons:
1. The concave lip of the expansion unit does not
grip enough ~o remove the spherical bushing.
2. The expansion unit is not slotted enough to
provide maximum surface contact of the gripping lip to
hold onto the bushing.
3. Depends totally on a dead end unit to provide a
pushing surface for extracting bolt to push against and
would be too long for most jobs in a confined area.
4. The double wedge system puts ~ide pressure on
~he inner portion of the bushing thus expanding the outer
portion and making it tighter; thus, removal is more
difficult.
U.S. Patent 4207664 discloses a pulling tool
for extracting bushings and bearings, but it i~ unsati~-
factory for the following reasons:
1. This uni~ is limited to extracting bushings
from dead end units and will not work with open ended set
ups .
2. Difficult to keep the expansion u~it in posi-
tion with the threads aligned while in6talling the
extraction bolt in a confined area.
The wedge-type extraction bolt exerts horizon-
tal and vertical pr~essure on the threads of the extrac-
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tion bolt thus increasing the amount of torque necessary
which would be difficult to supply with an Allen wr~nch.
It is one object of the present invention,
therefore, to provide an improved extractor tool or pull-
ing device for bearings, bushings and the lik0 which is
designed in an improved manner to provide the necessary
pulling force and to provide the necessasry grasping
technique on the bearing sleeve to which the force is to
be applied.
According to the invention, therefore,.it is
provided an extractor tool for bearings, bushings and the
like having a bore within which a shaft is normally
received, the tool comprising an inner puller body which
has a substantially cylindrical outer surface and an
inner bore extending axially therealong, one end of the
body including integrally therewith a grasping portion
having an outer surface thereof which is substantially
cylindrical for entering said bore and includes a sub-
stantia1ly radially extending lip defined by a shoulder
facing toward an opposed end of the body and including a
plurality of longitudinal slots dividing said grasping
portion into a plurality of grasping members each of
which can flex outwardly to cause said lip to engage
behind a rear face of said bearing, bushing or the like,
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a bolt for extending along said inner bore ha~ing a head
at one end for engaging an end face at said opposed end
of said inner puller body and a male screw threaded por-
tion at an opposed end thereof arranged, with said head
at said opposed end, to extend outwardly at said one end
of the body, a wedge member having a female screw thrsad
therein such that rotation of the bolt rela~ive to the
wedge member causes the wedge member to be drawn axially
to engage an inside surface of said grasping portion to
flex said grasping members outwardly, a portion of the
outer surface of said inner puller body having thereon a
screw thread, a nut for engaging said screw thread so as
to move axially when the nut is rotated relative to said
body, means on said body by which the body can be grasped
for holding said body against rotation, and an outer
puller body having ~n inner surface arranged to surround
said screw thread portion of ~he outer surface, one end
surface for enyaging said nut for axial movement of the
outer puller body with the nut and an opposed end face
spaced from the inner puller body for engaging an abut-
ment whereby rotation of said bolt causes said grasping
portion to grasp an inner face of said bushing, bearing
and the like and rotation of said nut causes said outer
puller body to engage said abutment and to force said
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inner puller body and said bearing, bushing and the like
in axial direction for removal.
With the foregoing in view, and other advan-
tages as will become apparent to those skilled in the art
to which this invention relates as this specification
proceeds, the invention is herein described by reference
to the accompanying drawings forming a part hereof, which
includes a description of the best mode known to the
appli~cant and of the preferred typical embodiment of the
principles of the present invention, in which:
DESCRIPTION OF THE DRAWINGS
Figure 1 is a cross-sectional view of an
ex~raction tool according to the invention in operation.
Figure 2 i5 a side elevational view of the tool
of Figure 1.
Figure 3 is a cross-sectional view on the lines
3-3 of Figure 1.
Fig~re 4 is a side elevational view of an
installation tool for use in association with the extrac-
tion tool.
In the drawings like characters of reference
indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
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A bushing is indicat~d schematically at 10
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mounted within a body 11 with the shaft on which the
bushing sits already removed leaving the hollow bore of
the bushing indicated at 12.
The puller for the bushing is generally indi-
cated at 13. The puller device is formed from a nu~ber
of separate parts. Firstly, there is an inner puller
body indicated at 14. The inner puller body comprises an
integral body which is generally cylindrical in shape
defin`ing an outer cylindrical peripheral surface 141 of a
diameter substantially equal to the diameter of the inner
surface 12 of the bushing. Part of the cylindrical sur-
face carries a screw thread 142 which extends from a
shoulder 143 along the peripheral surface toward a left-
hand end as shown in Figure 1. The shoulder 143 defines
a reduction in diameter of the peripheral surface down to
a qecond surface 144 with a further reduction in dia~eter
providing a surface 145 which carries a pair of flats 146
by which the inner puller body can be ~rasped and held
against rotation. An end of the inner puller body at the
righthand end of the surface 145 is indicated at 147.
The lethand end of the inner puller body is
machined to taper slightly inwardly over an area indicat-
ed at 148 down to a lip or shoulder 149 which faces in a
righthand direction as shown in Figure 1. The lip or
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shoulder is provided by a rib 150 at the lefthand end.
The section 148 is divided into 6 separately flexible
parts 151, 152, etc., by slots 153 which extend longitud-
inally and are equidistantly spaced around the axis of
the inner puller body. A central bore extends along the
full length of the inner puller body as indicated at 154
from the righthand end through to the lip 150. An inner
surface of the section 148 is machined to define a wedge
shape 155 which converges from a widest end at the lip
150 toward the bore 154 at the end of the flexible ~ieces
151, 152. Thus the radial thickness of each of the
pieces 151, 152 is reduced at the outermost end adjacent
the lip 150 so as to allow flexibility of those portions.
The whole of the inner body is manufactured from a suit-
able steel so that the portions 151, 152 can flex and can
return to their initial shape after the flexing force is
removed.
A central bolt 16 carries a hex head 161 for
engaging against a washer 17 and a sleeve 18 so as to
apply pressure to the end 147 of the inner puller body.
The end of the bolt 16 remote from the head 161 includes
a male screw thread 162 for cooperating with a female
screw thread 191 of a wedge member 19. The wedge member
19 has an outer surface 192 which substantially conforms
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to the inner surface 155 of the inner puller body so that
axial movement of the wedge member 19 acts to deform or
flex the portions 151, 152 outwardly. Axial movement of
the wedge member 19 is obtained by rotation of the head
161 so as to engage the screw threads 162 and 191.
In a first operation of the device, therefore,
with the wedge member 19 attached to the bolt 16 but
remote from the lip 150, the inner puller body can be
inserted through the bore 12 of the bushing to a position
where the lip 149 extends behind the rear edge of the
bushing. In this position, the bolt 16 is rotated to
draw the wedge member into the end of the inner puller
body so as to force the portions 151 and 152 outwardly to
en~age the lip against a rear surface of the bushing.
During the initial rotation to obtain necessary engage-
ment, manual movement of the inner puller body can be
provided to ensure that the engagement is properly align-
ed.
An outer puller body 20 comprises a s~eeve 201
welded on a radial plate 202, the latter having a central
bore 203 by which it can slide over the outer ~urface 141
of the inner puller body including over the screw thread
142. The diameter of the sleeve 201 is such that an end
face 204 thereof can engage around the outside of the
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bushing 10 onto the body 11. A washer 21 is shaped to
engage against an end face of the radial plate 202 and
also includes a central bore to allow it to move with the
outer puller body. A large hex nut 22 of the same gener-
al size as the outer surface of the puller body 20
includes an outer hex surface by which it can be gxasped
by a suitable large wrench or socket and an inner screw
threa~ 221 by which it can engage the screw thread 142 so
that rotation of the nut drives the o~ter puller body
axially along the inner puller body.
Thus, relative movement can be obtained between
the lip 149 and the edge 204 by rotation of the nut 22 to
cause relative movement between the bushing 10 and the
body 11 to extract the bushing. On a very hard pull when
the spherical bushing 10 is firmly in place, the inner
puller body may want to rotate and hence the flats 146
can be engaged by a suitable tool to prevent th~t rota- -
tion. The rotation of the nut 22 is continued until the
spherical bushing is inside the outer puller body.
It will be noted that the rotation of the nut
22 does not in any way affect the position of the wedge
member 19 and accordingly does not apply increased force
in the area of the wedge member and flexible portions
151, 152 after thosé parts have been moved to the requir-
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ed clamping position.
The following points of this device are ofparticular i~portance:
1. Can be used for removing roller bearings, bush-
ings of soft or hard steel.
2. Can be used for removing the same from open
ended or dead end units.
3. Provides good working depth for remo~ing spher-
ical bearings.
4. Uses a large hexagon nut threaded on the inner
extracting unit, pushing against the outer puller body
providing extreme pulling power.
5. Has two flats on the inner extracting unit
where an open ended wrench can be used to keep the whole
unit from turning.
6. Provides backing against the gear box to
relieve stress from the pull.
7. Can be used in a confined area without removing
gear box from implement.
8. Once inner extracting unit is tightened in
place, any torque applied to the extracting hexagon nut
does not increase outward pressure (expanding the spheri-
cal bushiny). All the Eorce is used to pull it out.
9. The grip~ ng lip of the slotted expansion por-
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tion of the inner extrac~ing unit provides secure grip on
the edge of the inner part oE the spherical bu~hing.
lO. The six slotted segments of the inner extract-
ing expansion unit provide grPater contact area for the
gripping lip on the inner edge of the sphe-ical bushing.
ll. Being made out of spring stsel, the slotted
expansion unit returns to original size after the spheri-
cal bushing is removed and the wedge is released.
12. The spherical bearing puller can be installed
in one unit and holds itself in place after th~ wedge is
tightened and will remain secure.
13. The brass washer between hexagon nut and outer
pulling body cuts down on the friction utilizing less
torque to xemove the bushing.
14. Out of the eight pieces, only two require spec-
ial machining. Therefore, the cost of manufacturing is
greatly reducedO
15. Three pieces c~n be purchased from the local
stores for replacements.
In Figure 4 is shown an installe~ body which
comprises a cylindrical shaft portion 25 ha~ing an end 26
and an outside diameter 6ubstantially equal to the inner
diameter 12 of the bushing. A shoulder 27 is provided at
the end of the portion 25 remote from the end 26 and
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formed on one end of an increased diameter portion 28.
The shoulder 27 therefore can engage one end face of the
bushing with the portion 25 inside the bore 12 thereof.
A transverse end 29 is defined on the body re~ote from
the end 26 for receiving hammer blows so that the should-
er 27 guided by the portion 25 acts to drive the bushing
into its required place within the body 11. If a bushing
of this type is installed using only a hammer, damage can
occur~ to the centre of the ~pherical bushing causing a
wedging effect.
The cylindrical shaft portion 25 also has a
quarter inch hole throughout the shaft (end to end~,
allowing for easier installation in a dead end housing,
thus not trapping any air.
Since various modification~ can be made in my
invention as hereinabove described, and many apparently
widely different embodiments of same made within the
spirit and scope of the claims without departing from
such spirit and ~cope, it is intended ~hat all matter
contained in the accompanying specification shall be
interpreted as illustrative only and not in a limiting
sense.
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