U.S. patent application number 15/148284 was filed with the patent office on 2016-09-01 for multispeed power tool.
The applicant listed for this patent is BLACK & DECKER INC.. Invention is credited to Brent A. KUEHNE.
Application Number | 20160250742 15/148284 |
Document ID | / |
Family ID | 46639339 |
Filed Date | 2016-09-01 |
United States Patent
Application |
20160250742 |
Kind Code |
A1 |
KUEHNE; Brent A. |
September 1, 2016 |
MULTISPEED POWER TOOL
Abstract
A tool with a transmission assembly having a reduction gearset
and a speed selector. The speed selector has a member, an actuator
and a shifter assembly. The member is movable between a first
position, in which the member is non-rotatable, and a second
position in which the member is coupled to a planet carrier of the
reduction gearset for common rotation. The actuator includes a
pivoting yoke and a follower that is coupled to the yoke. The
follower engages the member so as to be axially movable with the
follower. The shifter assembly has a selector switch, a switch
fork, and a pair of springs. The selector switch is slidable
between a first switch position and a second switch position. The
shift fork is slidably coupled to the selector switch and receives
the yoke. The springs cooperate to bias the shift fork relative to
the selector switch into a neutral position.
Inventors: |
KUEHNE; Brent A.; (Red Lion,
PA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
BLACK & DECKER INC. |
New Britain |
CT |
US |
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Family ID: |
46639339 |
Appl. No.: |
15/148284 |
Filed: |
May 6, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13220164 |
Aug 29, 2011 |
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15148284 |
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61513206 |
Jul 29, 2011 |
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Current U.S.
Class: |
173/47 |
Current CPC
Class: |
B23B 2260/044 20130101;
B23B 45/008 20130101; B25F 5/001 20130101 |
International
Class: |
B25F 5/00 20060101
B25F005/00; B23B 45/00 20060101 B23B045/00 |
Claims
1. A tool comprising: a housing assembly defining a handle; a motor
housed in the housing; a transmission assembly received in the
housing assembly, the transmission assembly having a reduction
gearset; the transmission assembly further including a locking
member including a plurality of locking projections, the locking
member including a circular hole; wherein the reduction gearset has
a first ring gear and is selectively operable in a first overall
gear ratio and a second overall gear ratio; wherein the
transmission assembly further includes a movable member, the
movable member including locking teeth; and wherein the movable
member in the transmission assembly non-rotatably engages the
locking member when the transmission assembly is operated in the
first overall gear ratio through engagement of the movable member
locking teeth with the locking projections and wherein the movable
member locking teeth and the locking projections are disengaged
when the transmission assembly is operated in the second overall
gear ratio so as to allow rotation of the movable member relative
to the locking member; and wherein the locking member is held in a
gear case in a circumferentially extending groove in a manner that
restricts relative rotation and axial movement of the locking
member with respect to the gear case.
2. The tool according to claim 1, wherein the groove is
non-circular.
3. The tool according to claim 2, wherein the locking member
includes a locking member body and projections extending from the
body to fit in the groove.
4. The tool according to claim 1, wherein the locking member is
restrained in the axial direction by two portions of the gear
case.
5. The tool according to claim 1, wherein the circular hole is
disposed at a center of the locking member.
6. The tool according to claim 1, wherein the locking member
includes a locking member body and wherein the circular hole is
located in the locking member body.
7. The tool according to claim 1, wherein the locking projections
extend about perpendicularly from the locking member body.
8. The tool according to claim 1, wherein the locking member has a
closed shape.
9. The tool according to claim 1, wherein the locking member has a
closed circular shape.
10. A tool comprising: a housing assembly defining a handle; a
motor housed in the housing; a transmission assembly received in
the housing assembly, the transmission assembly having a reduction
gearset; the transmission assembly further including a locking
member including a plurality of locking projections; wherein the
reduction gearset has a first ring gear and is selectively operable
in a first overall gear ratio and a second overall gear ratio;
wherein the transmission assembly further includes a movable
member, the movable member including locking teeth; wherein the
movable member in the transmission assembly non-rotatably engages
the locking member when the transmission assembly is operated in
the first overall gear ratio through engagement of the movable
member locking teeth with the locking projections and wherein the
movable member locking teeth and the locking projections are
disengaged when the transmission assembly is operated in the second
overall gear ratio so as to allow rotation of the movable member
relative to the locking member; wherein the locking member is held
in a gear case in a circumferentially extending groove in a manner
that restricts relative rotation and axial movement of the locking
member with respect to the gear case; and wherein the locking
member has a closed shape.
11. The tool of claim 10, wherein the locking member has a closed
circular shape.
12. The tool of claim 10, wherein the groove is non-circular.
13. The tool of claim 11, wherein the locking member includes a
locking member body and projections extending from the body to fit
in the groove.
14. The tool according to claim 10, wherein the locking member is
restrained in the axial direction by two portions of the gear
case.
15. The tool according to claim 10, wherein locking member includes
a circular hole; and wherein the circular hole is disposed at a
center of the locking member.
16. The tool according to claim 15, wherein the locking member
includes a locking member body and wherein the circular hole is
located in the locking member body.
17. The tool according to claim 16, wherein the locking projections
extend about perpendicularly from the locking member body.
18. A tool comprising: a housing assembly defining a handle; a
motor housed in the housing; a transmission assembly received in
the housing assembly, the transmission assembly having a reduction
gearset; the transmission assembly further including a locking
member including a plurality of locking projections, the locking
member including a locking member body and a hole in the locking
member body; wherein the reduction gearset has a first ring gear
and is selectively operable in a first overall gear ratio and a
second overall gear ratio; wherein the transmission assembly
further includes a movable member, the movable member including
locking teeth; wherein the movable member in the transmission
assembly non-rotatably engages the locking member when the
transmission assembly is operated in the first overall gear ratio
through engagement of the movable member locking teeth with the
locking projections and wherein the movable member locking teeth
and the locking projections are disengaged when the transmission
assembly is operated in the second overall gear ratio so as to
allow rotation of the movable member relative to the locking
member; wherein the locking member is held in a gear case in a
circumferentially extending groove in a manner that restricts
relative rotation and axial movement of the locking member with
respect to the gear case; and wherein the locking member has a
closed shape.
19. The tool of claim 18, wherein the groove is non-circular; and
wherein the locking member includes projections which extend from
the locking member body and engage the groove.
20. The tool of claim 19, wherein the locking member is restrained
in the axial direction by two portions of the gear case.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation application of application Ser. No.
13/220,164, entitled MULTISPEED POWER TOOL filed Aug. 29, 2011,
which is hereby incorporated by reference in their entirety.
FIELD
[0002] The present disclosure relates to a multispeed power
tool.
BACKGROUND
[0003] Various multispeed power tools are known in the art. Several
of the known arrangements suffer from one or more drawbacks,
including difficulties in shifting the tool to operate in a
different overall gear reduction ratio, and/or a relatively high
part count in the tool. Accordingly, there remains a need in the
art for an improved multispeed power tool.
SUMMARY
[0004] In one form, the present teachings provide a tool with a
housing assembly and a transmission assembly. The housing assembly
defines a handle. The transmission assembly is received in the
housing assembly and includes a reduction gearset and a speed
selector mechanism. The reduction gearset has a plurality of
planetary stages. The speed selector mechanism has a movable
member, an actuator and a shifter assembly. The movable member is
movable parallel to a longitudinal axis of the transmission
assembly between a first position, in which the movable member is
non-rotatably coupled to the housing assembly, and a second
position in which the movable member is coupled to a planet carrier
of the reduction gearset for common rotation. The actuator includes
a yoke, which is pivotally coupled to the housing assembly, and a
follower that is coupled to the yoke. The follower engages the
movable member so as to be axially movable with the follower. The
shifter assembly has a selector switch, a switch fork, and a pair
of biasing springs. The selector switch is slidably mounted to the
housing assembly and movable between a first switch position and a
second switch position. The shift fork is slidably coupled to the
selector switch and receives the yoke. The biasing springs
cooperate to bias the shift fork relative to the selector switch
into a neutral position.
[0005] In another form, the present disclosure provides a tool that
includes a housing assembly and a transmission assembly. The
housing assembly defines a handle and includes a gearcase. The
transmission assembly is wholly received in the gearcase and has a
reduction gearset and a thrust washer. The reduction gearset has a
movable member that is selectively movable between a first
position, in which the transmission assembly operates in a first
overall gear ratio, and a second position in which the transmission
assembly operates in a second overall gear ratio. The housing
assembly further includes a ring structure that is non-rotatably
coupled to the gearcase. The ring structure has a plurality of
teeth and a plurality of bosses that are received in longitudinal
grooves formed in the gearcase. The movable member has locking
teeth that engage the teeth of the ring structure when the movable
member is in the second position.
[0006] In still another form, the teachings of the present
disclosure provide a tool that includes a housing assembly, which
defines a handle, and a transmission assembly that is received in
the housing assembly. The transmission assembly has a reduction
gearset and a thrust washer. The reduction gearset has a first ring
gear and is selectively operable in a first overall gear ratio and
a second overall gear ratio. The thrust washer limits axial
movement of the first ring gear in a predetermined direction. A
movable member in the transmission assembly non-rotatably engages
the thrust washer when the transmission assembly is operated in the
first overall gear ratio.
DRAWINGS
[0007] The drawings described herein are for illustrative purposes
only of selected embodiments and not all possible implementations,
and are not intended to limit the scope of the present
disclosure.
[0008] FIG. 1 is a side elevation view of an exemplary tool
constructed in accordance with the teachings of the present
disclosure;
[0009] FIG. 2 is a longitudinal section view of a portion of the
tool of FIG. 1;
[0010] FIG. 3 is a rear perspective view of a portion of the tool
of FIG. 1 illustrating a gear case in more detail;
[0011] FIG. 4 is a right side elevation view of the gear case shown
in FIG. 3;
[0012] FIG. 5 is a partly sectioned right side elevation view of a
portion of the tool of FIG. 1;
[0013] FIG. 6 is a top perspective view of a portion of the tool of
FIG. 1 illustrating a shifter assembly in detail;
[0014] FIG. 7 is a right side elevation view of the shifter
assembly shown in FIG. 6;
[0015] FIG. 8 is a bottom perspective view of the shifter assembly
shown in FIG. 6;
[0016] FIG. 9 is a partly broken away top plan view of the tool of
FIG. 1;
[0017] FIG. 10 is an exploded perspective view of a portion of
another tool constructed in accordance with the teachings of the
present disclosure;
[0018] FIG. 11 is a longitudinal section view of a portion of the
tool of FIG. 10;
[0019] FIG. 12 is a partly sectioned right side elevation view of
another tool constructed in accordance with the teachings of the
present disclosure; and
[0020] FIG. 13 is a perspective view of a portion of the tool of
FIG. 12 illustrating a second thrust plate in more detail.
[0021] Corresponding reference numerals indicate corresponding
parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0022] With reference to FIGS. 1 and 2, an exemplary tool
constructed in accordance with the teachings of the present
disclosure is generally indicated by reference numeral 10. The tool
10 can include a housing assembly 12, a motor assembly 14, a
trigger assembly 16, a transmission assembly 18, a clutch assembly
20 and an output spindle 22.
[0023] The housing assembly 12 can comprise a pair of handle
housing shells 30 and a gear case 32 that can be removably coupled
to the handle housing shells 30 via a plurality of threaded
fasteners (not shown). The handle housing shells 30 can cooperate
to define a handle 36, a trigger mount 38, and a cavity 40 into
which the motor assembly 14 can be received.
[0024] With reference to FIGS. 2 through 4, the gear case 32 can
form at least a portion of an exterior of the tool 10 and can
include a first wall 46, a shoulder wall 48 and a second wall 50.
The first wall 46 can be a generally tubular structure that can
have a shifter mount 52 and a pair of guide channels 54 (see FIG.
4--only one shown). The shifter mount 52 can define a shifter
tongue 56, which can extend generally parallel to a longitudinal
axis of the gear case 32 and can be received into a slot (not
shown) formed in the handle housing shells 30 (FIG. 1), a shifter
aperture 58, which can extend through the shifter tongue 56 and can
be disposed generally parallel to a longitudinal axis of the gear
case 32, and a detent mount 60 (FIG. 9). The guide channels 54 can
be positioned on the interior surface 64 of the first wall 46
generally parallel to the longitudinal axis of the gear case 32 and
generally perpendicular to the shifter aperture 58 so that the
shifter aperture 58 is disposed between the guide channels 54. The
shoulder wall 48 can be an annular structure that can couple the
first and second walls 46 and 50 to one another. In the example
provided, the shoulder wall 48 extends radially outward from the
second wall 50 to the first wall 46. The shoulder wall 48 can
define a set of clutch element apertures 70, a central bore 72 and
a plurality of locking lugs 74. The clutch element apertures 70 can
be disposed radially outwardly of the second wall 50 and can extend
through the shoulder wall 48 so as to terminate within the interior
of the first wall 46. The locking lugs 74 can be formed on an axial
end of the shoulder wall 48 so as to face the interior volume
defined by the first wall 46. The second locking lugs 74 can be
disposed radially between the central bore 72 and the clutch
element apertures 70. The second wall 50 can be a generally tubular
structure that can extend axially from the shoulder wall 48 on a
side opposite the first wall 46. The second wall 50 can have an
externally threaded portion 80, a keyway 82, a retaining ring
groove 86 and a key 88. The keyway 82 can be disposed on the
exterior of the second wall 50 and can extend longitudinally
through the threaded portion 80. The retaining ring groove 86 can
be formed in the exterior of the second wall 50 on an end of the
second wall 50 opposite the shoulder wall 48. The key 88 can be
formed on the interior of the second wall 50 and can extend in a
longitudinal direction that is parallel to the longitudinal axis of
the gear case 32.
[0025] The motor assembly 14 and the trigger assembly 16 can be
conventional in their construction and operation. In brief, the
motor assembly 14 can include an output shaft 92 that can provide a
rotary input (torque) to the transmission assembly 18, while the
trigger assembly 16 can be mounted to the trigger mount 38 and
employed to selectively couple the motor assembly 14 to a source of
electrical power, such as a battery pack 94. In the example
provided, the trigger assembly 16 includes a trigger 96, a trigger
switch 98, and a reversible variable speed controller 100, but it
will be appreciated that various other types of trigger assemblies
could be substituted for the particular trigger assembly that is
shown in the drawings and described herein.
[0026] With reference to FIGS. 2 and 5, the transmission assembly
18 can be configured to transmit rotary power between the motor
assembly 14 and the output spindle 22 and can comprise a
transmission sleeve 104, a reduction gearset 106 and a speed
selector mechanism 108.
[0027] The transmission sleeve 104 can be a tubular structure that
can be formed of a suitable material, such as plastic, and can be
axially and non-rotatably coupled to the gear case 32 in any
desired manner. In the particular example provided, both the first
wall 46 of the gear case 32 and the transmission sleeve 104 have a
plurality of circumferentially spaced-apart bosses 112 and 114,
respectively, that axially abut one another. The bosses 114 on the
transmission sleeve 104 can be matingly received in corresponding
longitudinally extending grooves 116 formed on the interior surface
of the first wall 46 such that receipt of the bosses 114 in the
grooves 116 inhibits rotation of the transmission sleeve 104
relative to the gear case 32. Additionally or alternatively,
fasteners can be employed to non-rotatably couple and optionally
fixedly couple the transmission sleeve 104 to the first wall 46. In
the example provided, the fasteners comprise threaded fasteners 118
that extend through the bosses 114 in the transmission sleeve 104
and threadably engage the bosses 112 in the first wall 46, but it
will be appreciated that various other types of fasteners,
including rivets or pins, could be employed to fixedly couple the
transmission sleeve 104 to the first wall 46.
[0028] The transmission sleeve 104 can include a first sleeve
portion 122 and a second sleeve portion 124. The first sleeve
portion 122, which can be disposed adjacent the motor assembly 14,
can be formed with a non-circular lateral cross-sectional shape,
such as a toothed shape, and can be somewhat larger in diameter
than the second sleeve portion 124. A plurality of teeth 128 formed
on an interior cylindrical surface of the second sleeve portion 124
on an axial end thereof opposite the end to which the first sleeve
portion 122 abuts.
[0029] The reduction gearset 106 can be a multi-speed gearset and
in the particular example provided, comprises a three-stage,
two-speed planetary transmission having a first stage 130, a second
stage 132 and a third stage 134. The first and second stages 130
and 132 can be disposed in the transmission sleeve 104, while the
third stage 134 can be disposed in the gear case 32.
[0030] The first stage 130 can comprise a first sun gear 140, which
can be coupled to the output shaft 92 of the motor assembly 14 for
rotation therewith, a first planet carrier 142, a plurality of
first planet gears 144 and a first ring gear 146. The first planet
carrier 142 can comprise a first carrier body 148 and a plurality
of first pins 150 that are fixedly coupled to and extend from the
first carrier body 148. The first carrier body 148 comprises a
plurality of first locking teeth 152 that can be disposed on an
outer circumferential surface of the first carrier body 148. Each
of the first planet gears 144 can be rotatably disposed on a
corresponding one of the first pins 150 and can have teeth that are
meshingly engaged with teeth of the first sun gear 140 and teeth of
the first ring gear 146. The first ring gear 146 can be
non-rotatably coupled to the transmission sleeve 104. In the
example provided, the first ring gear 146 has a lateral
cross-sectional shape that is complementary to the lateral
cross-sectional shape of the first sleeve portion 122 so that the
first ring gear 146 is non-rotatably coupled to the transmission
sleeve 104 when it is inserted into the first sleeve portion 122. A
first thrust washer 156 can be received into the first sleeve
portion 122 on a side of the first ring gear 146 opposite to the
second sleeve portion 124 to limit movement of the first ring gear
146 in an axial direction away from the second sleeve portion
124.
[0031] The second stage 132 can comprise a second sun gear 160, a
second planet carrier 162, a plurality of second planet gears 164
and a second ring gear 166. The second sun gear 160 can be coupled
to the first carrier body 148 for rotation therewith. In the
particular example provided, the first carrier body 148 and the
second sun gear 160 are integrally and unitarily formed in a
suitable manner, such as compressed and sintered powdered metal. A
pilot aperture 168 can be formed into the first carrier body 148
and/or the second sun gear 160 and can receive an end of the output
shaft 92 of the motor assembly 14. The second planet carrier 162
can comprise a second carrier body 170 and a plurality of second
pins 172 that are fixedly coupled to and extend from the second
carrier body 170. Each of the second planet gears 164 can be
rotatably disposed on a corresponding one of the second pins 172
and can have teeth 174 that are meshingly engaged with teeth of the
second sun gear 160 and internal teeth 176 of the second ring gear
166. The second ring gear 166 can be received concentrically about
the second planet gears 164.
[0032] The third stage 134 can include a third sun gear 180, a
third planet carrier 182, a plurality of third planet gears 184 and
a third ring gear 186. The third sun gear 180 can be coupled to the
second carrier body 170 for rotation therewith. In the particular
example provided, the second carrier body 170 and the third sun
gear 180 are integrally and unitarily formed in a suitable manner,
such as compressed and sintered powdered metal. A pilot pin 188 can
extend from the second sun gear 160 and can be received into a bore
190 formed into the second carrier body 170 and/or the third sun
gear 180. The third planet carrier 182 can comprise a third carrier
body 192 and a plurality of third pins 194 that are fixedly coupled
to and extend from the third carrier body 192. Each of the third
planet gears 184 can be rotatably disposed on a corresponding one
of the third pins 194 and can have teeth that are meshingly engaged
with teeth of the third sun gear 180 and internal teeth of the
third ring gear 186. The third ring gear 186 can be received
concentrically about the third planet gears 184 and can be
rotatably disposed within the first wall 46.
[0033] A second thrust washer 198 can be disposed axially between
the transmission sleeve 104 and the gear case 32 and can limit
axial movement of the second planet carrier 162 in a direction away
from the motor assembly 14, as well as limit axial movement of the
third ring gear 186 toward the motor assembly 14.
[0034] The output spindle 22 can be drivingly coupled to the third
planet carrier 182 in any desired manner, such as directly coupled
to the third carrier body 192. In the example provided, however, a
conventional spindle lock assembly 200 is employed to drivingly
couple the third planet carrier 182 to the output spindle 22 in a
manner that permits the third planet carrier 182 to drive the
output spindle 22 (in either rotational direction) but which
inhibits the transmission of rotary power from the output spindle
22 to the third planet carrier 182 so that the output spindle 22
cannot be rotated to back-drive the reduction gearset 106. As the
spindle lock assembly 200 is conventional in its configuration and
operation, a detailed discussion of the spindle lock assembly 200
need not be provided herein. Briefly, the spindle lock assembly 200
comprises an anvil 204, a plurality of pins (not shown) and a ring
structure 208, which is non-rotatably coupled to the housing
assembly 12. The pins are disposed radially between the anvil 204
and the ring structure 208 and circumferentially between lugs (not
shown) that extend axially from the third carrier body 192.
Rotation of the third planet carrier 182 that would tend to drive
the output spindle 22 causes corresponding rotation of the pins
with the anvil 204 within the ring structure 208, while rotation of
the output spindle 22 that would tend to drive the third planet
carrier 182 causes rotation of the anvil 204 in a manner that urges
the pins radially outwardly such that the pins wedge between the
ring structure 208 and the anvil 204 to thereby lock the output
spindle 22 to the housing assembly 12.
[0035] In the particular example provided, the ring structure 208
is coupled to the housing assembly 12 in a novel manner. More
specifically, the ring structure 208 comprises a ring body 220 with
a plurality of circumferentially spaced-apart teeth 222 that are
meshingly engaged with the locking lugs 74 formed on the shoulder
wall 48 of the gear case 32.
[0036] Bearings 230 can be received between the second wall 50 of
the gear case 32 and the output spindle 22 and can support the
output spindle 22 for rotation relative to the gear case 32.
[0037] With reference to FIGS. 2 and 5, the speed selector
mechanism 108 can comprise a movable member 240, an actuator 242
and a shifter assembly 244.
[0038] The movable member 240 can be axially movable between a
first position and a second position to cause the reduction gearset
106 to operate in a first overall gear ratio and a second overall
gear ratio, respectively. In the example provided, the movable
member 240 is the second ring gear 166 and is slidably disposed in
the second sleeve portion 124 of the transmission sleeve 104 so as
to be movable between the first position and the second position.
Positioning the movable member 240 in the first position meshingly
engages a plurality of second locking teeth 248 on the outer
circumferential surface of the movable member 240 to the teeth 128
formed on the interior circumferential surface of the second sleeve
portion 124 (to thereby non-rotatably couple the movable member 240
and the second ring gear 166 to the gear case 32 via the
transmission sleeve 104), while positioning the movable member 240
in the second position meshingly engages the internal teeth 176 of
the second ring gear 166 to the first locking teeth 152 formed on
the first carrier body 148. It will be appreciated that the
internal teeth 176 of the second ring gear 166 are decoupled from
the first locking teeth 152 on the first carrier body 148 when the
movable member 240 is in the first position, and that the second
locking teeth 248 on the movable member 240 are decoupled from the
teeth 128 on the second sleeve portion 124 when the movable member
240 is in the second position.
[0039] The actuator 242 can comprise a yoke 260 and a follower 262.
The yoke 260 can have an input tab 270, a pair of pivot mounts 272
and a pair of follower mounts 274. The yoke 260 can be received
over the transmission sleeve 104 such that the input tab 270 is
disposed vertically in-line with the shifter aperture 58. The pivot
mounts 272 pivotally couple the yoke 260 to the transmission sleeve
104 and can be positioned at a desired point between the input tab
270 and the follower mounts 274 so as to provide a desired ratio of
movement between the input tab 270 and the follower mounts 274. In
the particular example provided, the pivot mounts 272 are
positioned so that the follower mounts 274 move in an axial
direction (parallel to the longitudinal axis of the gear case 32)
by an amount that is about equal to the amount in which the input
tab 270 is moved. Each of the follower mounts 274 can comprise a
slotted aperture 280 that can extend radially toward a point about
which an associated one of the pivot mounts 272 pivotally couples
the yoke 260 to the transmission sleeve 104. The follower 262 can
be configured to transmit movement of the follower mounts 274 in an
axial direction to the movable member 240. In the example provided,
the follower 262 has follower body 290 and a pair of ears 292. The
follower body 290 can be formed of wire in a generally half-moon
shape and can be received in a circumferentially extending groove
294 formed about the movable member 240. Accordingly, it will be
appreciated that the follower body 290 is received within the first
wall 46 of the gear case 32. The ears 292 can extend radially
outwardly from the follower body 290 through longitudinal slots 298
in the first wall 46 and can be received into the slotted apertures
280 in the follower mounts 274. It will be appreciated that the
yoke 260 can be pivoted about the pivot mounts 272 to axially move
the follower 262 so that the movable member 240 may be translated
between the first and second positions. Portions of the ears 292
that extend radially outwardly of the yoke 260 can be received in
the guide channels 54.
[0040] With reference to FIGS. 5 through 9, the shifter assembly
244 can comprise a selector switch 300, one or more detent springs
302 (FIG. 9), a switch fork 304 and first and second biasing
springs 306 and 308. The selector switch 300 can be received in the
shifter aperture 58 and can be configured to receive a manual
switching input from a user of the tool 10. The selector switch 300
can comprise a switch member 312 and a wire form 314 that can be
mounted to the switch member 312. The switch member 312 can define
a pair of first rails 320, which can be oriented generally parallel
to a direction in which the switch member 312 is translated
relative to the housing assembly 12, a cross-member 322 and a pair
of second rails 324. Each of the second rails 324 can be oriented
relative to an associated one of the first rails 320 such that were
the first rails 320 (extended) to intersect the second rails 324,
they would create an outboard interior angle 326 that is less than
about forty-five degrees. The wire form 314 can include a first bar
member 330, a pair of second bar members 332 and a pair of detent
members 334. The first bar member 330 can abut the cross-member
322, while each of the second bar members 332 can be abutted
against an associated one of the first rails 320. Locking tabs 338
or other features can be employed to aid in fixing the second bar
members 332 to the switch member 312. Each of the detent members
334 can be formed as a leaf spring that is connected to an end of a
corresponding one of the second bar members 332 on a side opposite
the first bar member 330. The detent members 334 are configured to
compress inwardly when the switch member 312 is moved between
various switch positions such that the distal ends 342 of the
detent members 334 follow their associated second rail 324 to
thereby axially extend the detent members 334 while reducing the
extent to which they extend laterally outwardly from the switch
member 312.
[0041] The detent springs 302 can be leaf springs that can be
mounted to the detent mount 60 on the gear case 32. The detent
springs 302 can be contoured to receive the detent members 334 of
the wire form 314 so as to permit the selector switch 300 to be
selectively positioned in a first switch position and a second
switch position.
[0042] The switch fork 304 can be slidably mounted on the switch
member 312 between a pair of fork rails 350 and can receive the
input tab 270 on the yoke 260. The first and second biasing springs
306 and 308 can be positioned on opposite sides of the switch fork
304 and can abut opposite ends of the switch member 312. The first
and second biasing springs 306 and 308 can cooperate to bias the
switch fork 304 into a neutral position. Spring guides 354 can be
integrated into the switch fork 304 or the switch member 312 to
guide the first and second biasing springs 306 and 308.
[0043] In the particular example provided, the switch member 312 is
formed in two pieces (i.e., an upper switch member 360 and a lower
switch member 362). The upper switch member 360 can include the
first and second rails 320 and 324, while the lower switch member
362 can include the cross-member 322 and the fork rails 350. The
wire form 314 can be mounted to the upper switch member 360 such
that the second bar members 332 abut the first rails 320 and the
detent members 334 abut the second rails 324. The first and second
biasing springs 306 and 308 can be assembled to the switch fork 304
and that assembly can be dropped into the lower switch member 362
such that the switch fork 304 is received between the fork rails
350. It will be appreciated that an upper side of the switch fork
304 is sized such that the switch fork 304 cannot drop completely
through the fork rails 350. The upper and lower switch members 360
and 362 can be fixedly coupled to one another by any desired means
to thereby capture the switch fork 304 and the first and second
biasing springs 306 and 308 therebetween.
[0044] With reference to FIGS. 2, 5 and 8, the switch member 312
can be axially translated from the first switch position to the
second switch position to rotate the yoke 260 about the pivot mount
272 to thereby translate the follower 262 to cause the movable
member 240 to move from the first position to the second position.
In the event that the internal teeth 176 on the second ring gear
166 are not aligned to the first locking teeth 152 on the first
carrier body 148, the switch member 312 may be positioned in the
second switch position without fully translating the switch fork
304 such that the second biasing spring 308 is compressed. When the
internal teeth 176 on the second ring gear 166 come into alignment
with the first locking teeth 152 on the first carrier body 148, the
force provided by the second biasing spring 308 will urge the yoke
260 to pivot about the pivot mount 272 such that the follower 262
will translate the movable member 240 into the second position.
[0045] The switch member 312 can also be axially translated from
the second switch position to the first switch position to rotate
the yoke about the pivot mount 272 to thereby translate the
follower 262 to cause the movable member 240 to move from the
second position to the first position. Should the second locking
teeth 248 on the movable member 240 not be aligned to the teeth 128
on the second sleeve portion 124, the switch member 312 may be
positioned in the first switch position without fully translating
the switch fork 304 such that the first biasing spring 306 is
compressed. When the second locking teeth 248 on the movable member
240 come into alignment with the teeth 128 on the second sleeve
portion 124, the force provided by the first biasing spring 306
will urge the yoke 260 to pivot about the pivot mount 272 such that
the follower 262 will translate the movable member 240 into the
first position.
[0046] Returning to FIG. 2, the clutch assembly 20 can comprise a
clutch profile 390, a plurality of clutch elements 392, a first
thrust plate 394, a plurality of clutch springs 396, a spring
follower 398, an adjustment nut 400, an adjustment collar 402, a
second thrust plate 404 and a retaining ring 406. The clutch
profile 390 can be fixedly coupled to (e.g., unitarily formed with)
the third ring gear 186. The clutch elements 392 can be received
through the clutch element apertures 70 in the shoulder wall 48 in
the gear case 32 and can engage the clutch profile 390. In the
particular example provided, the clutch elements 392 are single
spherical balls, but it will be appreciated that other forms of
clutch elements, including pins or stacked spherical balls, may be
employed in the alternative. The first thrust plate 394 can be a
washer that can be received over the clutch elements 392 on a side
opposite the clutch profile 390. The clutch springs 396 can be
helical compression springs that can be spaced circumferentially
about the second wall 50 of the gear case 32. The spring follower
398, which can be slidably mounted on the second wall 50 of the
gear case 32, can engage the keyway 82 (FIG. 4) in the second wall
50 to thereby inhibit relative rotation between the spring follower
398 and the gear case 32. A first end of the clutch springs 396 can
be abutted against the first thrust plate 394 and a second,
opposite end of the clutch springs 396 can be received into the
spring follower 398. The adjustment nut 400 can be threadably
engaged to the threaded portion 80 of the second wall 50 and can be
employed to translate the spring follower 398 against the bias of
the clutch springs 396 to thereby adjust a clutch spring force
exerted against the clutch elements 392. The adjustment collar 402
can be non-rotatably but axially slidably mounted to the adjustment
nut 400 in a conventional manner that permits a user to rotate the
adjustment collar 402 (to thereby rotate the adjustment nut 400)
without causing corresponding translation of the adjustment collar
402. The retaining ring 406 can be received in the retaining ring
groove 86 and the second thrust plate 404 can be disposed on the
second wall 50 axially between the retaining ring 406 and the
adjustment collar 402 to thereby limit axial movement of the
adjustment collar 402 relative to the gear case 32.
[0047] From the foregoing, it will be appreciated that the gear
case 32 provides support for the transmission assembly 18, as well
as and the output spindle 22 and the clutch assembly 20. It will
also be appreciated that the second stage 132 can be configured
such that it has an overall diameter or size that is smaller than
the diameter or sizes of the first and third stages 130 and 134,
which can permit the speed selector mechanism 108 to be integrated
into the tool 10 in a nesting manner to thereby reduce the overall
height of the tool 10.
[0048] While the tool 10 has been described and illustrated as
having a transmission sleeve that is coupled to a gearcase, it will
be appreciated that a tool constructed in accordance with the
teachings of the present disclosure can be constructed somewhat
differently. For example, the gear case 32a can be constructed so
as to receive the reduction gearset 106 (FIG. 2) in its entirety as
shown in FIGS. 10 and 11. In this example, the teeth 128a are
formed on a ring-shaped structure 500 that is non-rotatably coupled
to the first wall 46a of the gear case 32a. In the example
provided, both the first wall 46a of the gear case 32a and the
ring-shaped structure 500 have a plurality of circumferentially
spaced-apart bosses 502 and 504, respectively, that axially abut
one another. The bosses 504 on the ring shaped structure 500 can be
matingly received in corresponding longitudinally extending grooves
506 formed on the interior surface of the first wall 46a such that
receipt of the bosses 504 in the grooves 506 inhibits rotation of
the ring shaped structure 500 relative to the gear case 32a.
Additionally or alternatively, fasteners can be employed to
non-rotatably couple and optionally fixedly couple the ring shaped
structure 500 to the first wall 46a. In the example provided, the
fasteners comprise threaded fasteners 510 that extend through the
bosses 504 in the ring shaped structure 500 and threadably engage
the bosses 502 in the first wall 46a, but it will be appreciated
that various other types of fasteners, including rivets or pins,
could be employed to fixedly couple the ring shaped structure 500
to the first wall 46a.
[0049] Another example is illustrated in FIGS. 12 and 13, in which
the tool 10b has a two-piece gear case 32b and the teeth 128b are
co-formed with the second thrust washer 198b. In this example, the
gear case 32b comprises a front case portion 600 and a rear case
portion 602 that abuts the front case portion 600. A
circumferentially extending groove 606 is formed at the joint 608
where the front and rear case portions 600 and 602 abut one
another. The circumferentially extending groove 606 can be formed
in a non-circular manner, such as with a plurality of lobes or
teeth (not shown). The second thrust washer 198b can have a thrust
washer body 610 that can have a non-circular shape that can
non-rotatably engage the gear case 32b when the thrust washer body
610 is received in the circumferentially extending groove 606. The
teeth 128b can be integrally and unitarily formed with the thrust
washer body 610 in an appropriate process, such as stamping, and
can extend in an axial direction away from the thrust washer body
610. Accordingly, it will be appreciated that the second locking
teeth 248 on the movable member 240 can engage the teeth 128b that
are fixedly coupled to the second thrust washer 198b when the
movable member 240 is positioned in the first position.
[0050] The foregoing description of the embodiments has been
provided for purposes of illustration and description. It is not
intended to be exhaustive or to limit the disclosure. Individual
elements or features of a particular embodiment are generally not
limited to that particular embodiment, but, where applicable, are
interchangeable and can be used in a selected embodiment, even if
not specifically shown or described. The same may also be varied in
many ways. Such variations are not to be regarded as a departure
from the disclosure, and all such modifications are intended to be
included within the scope of the disclosure.
* * * * *