Note: Descriptions are shown in the official language in which they were submitted.
21~ 2 S 8 7 62139-229E
' ..,',~
This is a division of our co-pending Canadian Patent
Application No. 2,022,966 filed 9th August l990.
The present invention relates generally to power
tools and, more particularly, to an air-operated ratchet tool.
Ratchet tools which are hand held and driven by an
air motor are well known. Such tools typically include a
housing having a fork at one end within which is disposed a
rotatable drive body for loosening and tightening fasteners.
In current air ratchet tools, the air motor is
located within the housing such that vibrations of the motor ---
.
which occur during operation of the tool are transferred to the
housing, thereby undesirably causing vibration of the tool `
. ~ . ...
while it is in the user's hand. Yurthermore, the motor is
located within the housing such that cold air produced by the -
motor durlng operation causes the housing to become cold, ;
thereby undesirably causing the surface of the tool to become
.
cold while it is in thè user's hand. ~`
A ratchet tool includes a knob which is rotatable ~-
between fastener-tightening and fastener-loosening positions.
Howevér~, the knob of currently available tools has a tendency
to undesirably move between these positions during use, where-
upon a fastener would be loosened even though the knob had been ;~
set to tighten the fastener or vice versa.
Since the knob of current ratchet-tools extends
outwardly from the surface of the housing, it is susceptible
to blows which result when the tool is dropped. The shock of
the blow to the knob is transferred to the housing, thereby ~ -
- 21~2587
~ 62739-229E
undesirably increasing the risk of damage to the housing in the
form of stress cracks or the like.
When a ratchet tool is operated, there is a tendency ;`~
to oscillate if there is not enough friction between the
fastener and the work piece. The ratchet tool typically
includes a mechanism associated with the drive body to prevent
such a slippage from occurring by providing friction between
the drive body and the fork or by providing another ratcheting `
mechanism between the drive body and the housing or by roller
clutching. Such friction has been provided by coil springs and ~ ~-
pins. This type of mechanism, however, is disadvantageous - ~ i
because it undesirably causes grooves to be formed in the ``
forks.
Additionally, current ratchet tools include a manifold
in the housing which provides inlet air to the motor and
receives exhaust air from the motor. The pulsating flow of
the exhaust air out of the motor causes the creation of
.- -
Helmholtz frequencies, resulting in undesirable operating noises.
In some current ratchet tools, a bushing is disposed -~ -
in an~opening in one arm of the fork. The bushing surrounds
the-drlve~body and is used for the transfer of operating loads ` -
from the drive body to the housing via the one fork arm. The
bushlng,~ however, is often not securely fit and accurately
locàted within the opening of its associated fork arm such that
it has a tendency to be rotated with the drive body or not
aligned~with the base of the other fork arm. As a result, :~
operating loads are not effectively transferred from the drive
body to the housing. ;~ -~
21~2S87
- 62739-229E
The housing of currently available ratchet tools is
comprised of three axially segmented members within which all
of the elements of the tool are located. With axial
segmentation, the manufacturing and assembly process is
necessarily complicated since it is difficult to machine
internal geometries accurately and locate and align each of
the elements within the housing. Further, it is difficult to
galn access to the alements in the event that repair of the ;~
tool is needed. ~ "'
Summàry of the Invention
The present invention provides a ratchet tool compris-
ing an elongated housing including a front end and a rear end,
-` motor means in the housing producing a-predetermined volume of
exhaùst airr a manifold in the rear end of the housing, the ;~
manifold including inlet means for delivering air to the motor -~
meàns and outlet means for receiving exhaust air from the motor
means, the outlet means including a chamber having a volume -~
~- oompared to the predetermined volume of exhaust air to dampen
and dissipate Helmholtz frequencies, drive means in the front
-~-20 end of~the housing, and means in the housing for coupling the `
motor~means to the drive means and thereby transferring power
from the motor means to the drive means.
- The invention consists of certain novel features and
a combination of parts hereinafter fully described, illustrated ;~
,
in the accompanying drawings, and~partlcularly pointed out in
the appended claims, it being understood that various changes
in the details may be made without departing from the spirit,
, ~ ,..
3 ;~
....
~ 2 1 ~ 2 ~
~- 62739~229E
,...
or sacrificing any of the advantages of the present invention.
Brief Description of thè Drawings -~ ;
:;~
For the purpose of facilitating an understandin Zl o the ~ -
invention, there is illustrated in the accompanying drawings a ` i`
preferred embodiment thereof, from an inspection of which, when
considered in connection with the following description, the
invention, its construction and operation, and many o its
advantages should be readily under-stood and appreciated.
- Fig. 1 is a perspective view of a ratchet tool ~
constructed in accordance with the features of the present ~ ;
invention;
Fig. 2 is a cross-sectional view of the ratchet tool,
on an enlarged scale, taken along the line 2-2 of Fig. l;
Fig. 3 is a partial plan view of the ratchet tool
without thè cover member, sectioned through the drive body and ~ ~?~
the motor;
Fig. 4 is a cross-sectional view of the ratchet tool, ~
taken àlong the line 4-4 of Fig. 3; ~;
. ;."~,
.
~ 4
21~2~7
.~
62739-229E
Fig. 5 is a cross-sectional view of the ratchet tool,
taken along the line 5-5 of Fig. 3;
Fi~. 6 is a plan view of t.he inner surface of the base
member of the ratchet tool;
Fig. 7 is a plan view of tl~e outer surface of the base ;- ;
member of the ratchet tool;
Flg. 8 is a plan view of the inner surface of the cover
member of the ratchet tool; ~ `
Fig. 9 is a perspective view of the jacket which -
surrounds the ratchet tool of Fig. 1, with a portion thereof
broken away to expose its interior; ~;
Fig. 9A is a cross-sectional view through the ~acket
and the housing, without any of the parts in the housing
depicted;
Fiq.~ 10 is an enlarged cross-sectional view of ~he ~ -
ratchet tool, taken along the line 10-10 of Fig. 2;
Fig. 11 is a perspective view of t~le manifold of the ~ -~
;ratchet tool, and an exploded view of the valve assembly
therein;
Fig. 12 is an end view of one end of the manifold;
" Fig. 13 is an end view of the other end of the
manifold;
Fig. 14 is a perspective view of one of the motor end '~-
members~and the gasket;
~: ~ Fig. 15 is an enlargenlen~ of that portion of Fig. 2
depicting the motor and end members;
Fig. 16 is a sectioned perspective view of the bearing
` block of the ratchet tool; ... -~ :
~; - Fig. 17 is an enlargement of that portion of Fig. 2
, .. . . ..
~ depicting the bearing block; ~ ~
` ~ ?
,;".~
- 2142~87
'' `
62739-229E '~
Fig. 18 is an exploded view of the drive assembl~; '' "~
Flg. 19 is an enlarged cross-sectional view, taken
along the line 19-19 of Fig. 2, with the two operating ' ~.,',
positions of the ear shown in phantom; '` '~'
Fig. 20 is an enlarged plan view of the bushing shown ';` ,;',`
ln Flg. 18;
Fig. 21 i~ an enlarged cross-sectlonal vlew oE ths
bushing and arm shown .in Fig~ 18; and ~ , ",'
Fig. 22 is a cross-sectional view taken along the line
22-22 oE Fig. 15.
~Detal,led,Dessri~t,,loe~ 2 ~5~ Em o ill!e~n ,,
Turning now to the drawings and, more particularly to
Fig. 1 thereof, there is depicted a ratchet tool designated ~:
10~, con,structed in accordance with the present invention. "` ,~
The ratchet tool 10 comprises an elongated housing 20 ` `,~''
including a front end 21 and a rear end 22. The housing 20 ~ ;,`~,''
includes an elongated, substantially semi-cylindrical base .'~
member 30 and an elongated, substantially semi-cylindrical ,~
cover member 80. The ratchet tool 10 comprises an exhaust .'~;,'"
nut~130 located at the rear end 22 of the housing 20, a
,paddle 216 pivotally secured to the base member 30, a motor i
;260 (Fig. 2) ijn the housing 20. The housing 20 inc-udes, at '``
the forya ~ end 21 thereof, a fork defined by arms 6l) and
99. ~A ra chet head 380 is disposed~ between these alms 60
and 99. A drive body 390 (Fig. 2) is carried by amls 60 and
99 and the~ratchet head 380. A knob 430 on the drive body ,~
~ is rotatable between fastener tightening and loosening '~
c~ ~ conditions. A sl:ud 393 (Fig. 2) at the end of the d~ive ! ~:
body 390 is adapted to receive a socket (not shown). The '`~
~position of the knob 430 is selected for tightening ~r
~ ,
21~2587
.;
62739-229E
loosening. The user's hand surrounds the housing 20 such
that his fingers are located outside the paddle 216. The
selected socket on the tool 10 receives the fastener (not
shown) to be loosened or tightened. Inlet air is introduced
to the tool 10 via a hose ~not shown) which i9 attached to
the exhaust nut 130. The inlet air is allowed to flow into
the motor by depresslng the paddle 216. The power produced
by the motor i5 transferred via coupling means to the ~-
ratchet head 380 which is caused to oscillate and which, in
turn, causes the rotatlon of the drive body 390 to cause the ~`
tightenlng or loosening of the fastener.
Referring to Figs. 6 and 7, the base member 30 is of
integral, one-piece construction and includes an inner
surface`31 and opposite longitudinal side edges 32 and 33.
Two front lugs 34 and 35 and two rear lugs 36 and 37 are
located along the opposite side edges 32 and 33
respectively. Each of the lugs 34-37 is formed lntegrally
with the member 30 and has a hole 38 tllerein. Each of the ;~
lugs 34 and 35 has an outer surface 39 defined by a part~
cylindrlcal portion 40 and part-conical portions 41 and 42
respectively`at opposite ends of the part-cylindrical
- ::
portion 40. Each of the lugs 36 and 37 has an outer surface ~;
43. A pedestal 44, located between the lugs 34 and 35, ;i --
~extends radially inwardly from the inner surface 31.
; , Furt.her, an abutment 45 is located on the inner surface 31 !, E-~
adjacent the lugs 36 and 37 and extends between the opposite ~ d
side edges 32 and 33. Still further, a rectangularly shaped ~ ;
recess 70 is located on the inner surface 31. , ``~
The rear end of the base member 30 lrlcludes a semi-
cylindrical reduced diameLer portion ha~ing a recess 46 and ~ ;
:,;:, ;i
~ ` 7
. ". ~:
- 21~2587
62739-229E
includes a semi-ci~cumfe~en~ial shoulder 47 on the inner ~- -
surface ~1. A palr of tabs 68 extend out-~nrdly from the
- shoulder 47.
The base member 30 includes an outer surface 48 wlth a
plurallty of recesses 49-52 respectlvely allgned with the ;~ ~`
lugs 34-37. Protrudlng outwardly from the outer surface 48 ~ -
are longltudinally extending walls 53 and 54 and a laterally
extending wall 55. A circular opening 56 and a recess 57
are loc~ted between the wnlls 53 and 54. Two recesses 58 ``
nre respectlvely located outside the walls 53 and 54, and
ad~acent thereto. The recesse~ 57 and 58 are laterally ~ -
aligned. Finally, a projeceion 59 corresponds to the recess j~
70 on the inner surface 31.
- The base member 30 includes, at its front end, a fork ;
, . -
or arm 60 having an outer surface 61 and an inner surface
62. An oval recess 69 is located on the innsr surface 62. `
As shown in Flg. 18, the arm 60 includes a cylindrical
surface 64 having a longitudinal axis Yl. A shoulder 65,
extends radially inwardly from the cylindrlcal surface 64.
The~shoulder 65 has an outer surface 66 defining a
cylindrical opening 63. A plurality of ribs 67 extend from 1`
the outer surface 66. In the preferred embodimone, the 11.
outer surface 6G has six ribs 67. The shoulder 65 is offset
from ehe surface 64 to define a pocket.
Referring to Fig. 8, ehe cover msmber 80 is of l ;~
integral, one-piece construction and includes an inner
surface 81 and opposite longitudinal side edges 82 and 83.
Two front lugs 84 and 85 and two rear lugs 86 and 87 are
located~along the opposite side edges 82 and 83,
respectively. Each of the lugs 84-87 is formed integrally
: -
~ 8
; ~ '";
~ 2142~i~7
62739-229E
with the member 80 and has a hole 88 ~l~erein. Each of ths ;~
lugs 8~ and 85 has an outer surface 89 ~efined by a part-
cyllndrlcal portion 90 and part-conical portions 91 and 92
respectively at opposite ends of the part-cylindrical
portion 90. Each of the lugs 86 and 87 has an outer surface
93. A pedestal 94, located between the lugs 84 and 85
extends radlally inwardly from t~le inner surface 81.
The rear end of the cover member 80 includes a semi- ~ ;
cylindrical reduced diameter portion having a recess 95 and
includes a shoulder 96 on the inner surface 81. A tab 97
extends axially inwardly from the shoulder 96.
The cover member 80 includes, at its front end, a fork
arm 99 having- an outer surface 100 (Fig. 1) and an inner
surface 101. An oval recess 106 is located on the inner
surface 101. As shown in Fig. 18, the arm 99 includes an
- ~ opening 102 defined by a cylindrical surface 103 having a
longitudinal axis Y2. A shoulder 104 extends radially
outwardly from the cylindrical surface 103. -~ <;
; ; Because the members 30 and 80 are separate, they can be
dle cost~or mol~ded instead of machined, ~hereby `J'~''S',.`-~
substantially reducing the cost of manufacturing ~he housing `
20. ~ The use of die casting or molding allows the shape and
`geometry of the elemen~s of the members 30 and 80 to be 1 -
controlled with a precision, consistency and accuracy at low `~ -~
~ cost which is not possible when machining is emyloyed. ~' ~
- Also, the use of two separate members obvia~es the '.'~ `5''
dlfflculties associated with machinlDg the lnner surface of
a unitary member.
As shown~in Fig. 4, the lugs 36 and 37 mate
: .,.~- ~;
;~ respectively-with the lugs 87 and 86 when the me~bers 30 and
- :' : ' `'.'.. i'~
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.: -: `, .,:,
.. - : . .:--~
.. , - ., `
21~2587
62739-229E
80 are secured together. In a like manner, and as shown in
Fig. 5, the lugs 34 and 35 mate respectively with the lugs
85 and 84. The holes 38 in the lugs 34-37 are aligned with
the holes 88 in the lugs 84-87. A screw 111 ~Figs. 4 and 5)
extends through each pair of mating holes 38 and 88 for ~ `
attachlng the two members 30 and 80 together. As shown ln
Fig. 5, when the two members 30 and 80 are attached
together, the side edges 32 and 33 of the base member 30 are
respectlvely ad~acent to the side edges 83 and 82 of the ~ `~
cover member 80 to define a juncture 112 .(Fig. 1) extending ;`
longltudlnally on each slde of the housing 20 from the rear
end 22 to the arms 60 and 99. Further, and as shown in Fig.
2, the recess 46 and the shoul~er 47 on the base member 30
mate respectively with the recess 95 and the shoulder 96 on ~;
the cover member 80. The al~s 60 and 99 are aligned such
that the longitudinal axis Yl is substantially aligned with
the longitudinal axis Y2. For cosmetic reasons, an
elongated gasket 113 (Figs. 4 and 5) is located in each of
the gaps 112.
As shown in Fig. 1, when the two members 30 and 80 are
attached together, the housing 20 comprises an elongated,
generally cylindrical grasping portion 107, a tapered
portion ~Q8 extending from the grasping portion 107, a neck
portion 109 extending from tlle tapered portion 108, and a
fork 110 defined by the arms 60 and 99, extending from the
neck portion 109. The arms 60 and 99 are parallel and -~
spaced from each other to deEine a receptacle for the
ratchet head 380. -
As shown in Fig. 9, there is provided a generally
cylindrical jacket 11~ for covering the rat~het tool lO.
.~
f~i,, 2~4~587
62739-229E
The jacket 114 includes an outer surface 115 and an inner
surface 116. The outer surface 115 has an elongated,
generally cylindrical portion 117, a tapered portion 118
extending from the cylindrical portion 117, a neck portlon
119 extending from the tapered portion 118, and a head
portion 120 extending from the neck portion 119~ Circular
openings 121 and 122 are located on opposite sides of the
head portion 120. Substantially parallel ribs 123 extend
longitudinally along the inner surface 116 respectively on
the sides of the jacket 114. In a specific form of the
invention, the inner end of each rib 123 was wider than the
portion nearest the main cylindrical portion of ~he jacket.
The jacket 114 also includes longitudinally extendillg, oval ~ ~`
openings 124, 125 and 126. The end of jacket 114 opposite `~
head portion 120 contains a pair of axially extending sllts ~ `
127 and a portion of reduced diameter having a groove 128
therein. A C-ring 12g is adapted to slip onto groove 128 as
will be described. That portion of the inside of the jacket `
aligned with the groove 128 is a projection that fits within .
the recesses 46 and 95.
The jacket 114 is composed of an elastomeric materlal,
and serves as a shock absorber during rough handling, as a
vibration isolator, as a thermal isolator and as a soft and
non-slip grip enhancer. Further, it protects the housing 20
from stress enhancing nicks and scratches, and prevents air ;i.`~
exhausted in the tool from reaching the user~s hand.
When the jacket- 114 is on the tool 10, the cylindrical ;
portion 117, the tapered portion 118, the neck portion 119,
and the head portion 120 mate respectively with the ;.
~cylindrical`portion 107, the tapered portion 108, the neck
. . - -, ,~, .
.....
11 ' ;`,'.'.',''.,'
.., . .;
~` 2~2~7
.. ..
62739-229E
portion 109, and the fork 110 of the housing 20. The ribs ~ -
123 are disposed respectively in the gaps on opposite sides
of the housing 20, whereby the jacket 114 is securely
fit to the housing 20. The pro~ection 59 on the ba.se member ~.
30 (Fig. 7) extends through the opening 12~, and the opo~ing : `.
126 mates with the opening 56 and the recess 57 in the base `
member 30. Still further, the circular openings 121 and 122
are allgned re~pectively with t)le openings 63 and 102 in the
arms 60 and 99. The opening 125 is aligne~ to allow the
identification of a serial number engraved on the outer - ;~
surface of the base member 30. ..
In order to assemble jacket 114 onto housing 20, a
lubricant.is preferably a~plied to inner surface 116. The
jacket is stretched and then slid into place on the housing `~
in such a way that the ribs 123 are respectively located in -~
the gaps 112 ~etween base member 3U and cover member 80, as
can be best seen in Fig. 9A. With the ribs so positioned, `:`~
~acket 114 is retained in place and does not ~wist with
~ respect to the housing. Then, C-ring 129 is applied to
;~. groove 128 whereby the projection corresponding to such groove is held in recesses 46 and 95.
- i .Ratchet tool 10 can be used with or without jacket 114.
When employed with the jacket, gasket 113 is not employed,
and, instead, is replaced with ribs 123 of jacket 114. -
~ s shown in Figs. 2 and 3, the exhaust nut 130
i - includes opposite ends 131 and 132, an outer surface 133,~and a longitudinally extending tllreaded bore 134. The outer
surface 133 has a circumferential recess 135. :
As shown in Fig. 2, the ratchet tool 10 further ;~
comprises a screw 140 inclu~ing an elongated body 141, a ;~
`
12 ~
.,, ~
~ .- .
f~ 21~25~8~
62739-229E
head 142 at one end of the body 141 and a nose 143 at the
other end of the body 141. The body 141 has a threaded
outer surface 144 and a circumferential recess 145. A bore
146 extends longitudinally from the body 141. The screw 140
i9 threaded lnto the bore 134 of the exhaust nut 130. ~n O-
ring 147 is disposed ~n the recess 145 to provide a seal
between the exhaust nut 130 and the screw 140. As shown ln
Fig. 2, a filter 148 is disposed in the bore 134 ad~acent
the head 142 of the screw 140. ~:
As shown in Figs. 2 and 10, the ratc~let ~ool 10
further comprises an annular seal ring 150 including an ``
outer surface 151. A washer 160 includes an outer surface :.
161, an opening 162 (Fig. 10) defined by an inner surface
163, and a plurality of apertures 164 extending radially '.
outwardly from the inner surface 163. Further, the washer
160 includes a plurality oE recesses 165 extending inwardly
from the outer surface 161.
The washer 160 is disposed within the housing 20 such ~s:
that its outer surface 161 contacts the inner surfaces 31 ~ `
and Bl respectively of the members 30 and 80. The washer ~ .
160~`is disposed against the shoulders 47 and 96 of the ,~
members 30 and 80. The recesses 165 mate with the tab 97 on ... `~
the inner surface 81 of the member 80, and the tabs 68 on ~ :.. :'
the lnner surface 31 of the member 30 to prevent rotation of
the~washer 160 within the housing 20. The inner surface 163
engages the outer surface 133 of the nut 130 extending
through the washer 160. In a like manner, the outer surface
151 of the seal 150 engages the inner surfaces 31 and 81 of .~
the members 30 and 80. `' `
',~` ', ~`,,',
` , ' .',
~ ` 13 :~
: F,~
21~2~87
~ 62739-229E
Referring to Figs. 11-13, the tool 10 further comprises
a generally cylindrical manifold 170, t}le manifold 170
lncluding a front end 171, a rear end 172 and a transverse
end wall 173 at the front end 171. The manifold 170 further
includes a circumferentlal peripheral edge 174 at the front
end 171 and a circumferential peripheral edge 175 at the
rear end 172. The peripheral edge 174 has a pair of
recesses 196 and 197. Further, the manifold 170 lncludeq an ~
outer surface 1~76 having opposed side recesses 177 and 178 ~ -
~Fig. 3) and a bottom recessed portion 179. The manifold
170 includes a transverse intermediate wall 180 and a
longitudinal 1ntermediate wall 181 extending between the-
transverse walls 173 and 180. The manifold 170 includes a
first passageway 182 (Fig. 2) located in the wall 180, a `;~
bore 183 tFig. 2) communicating with the first passageway
182, and a second passageway 184 in the wail 173
communicating with the bore 183. The wall 18Q has two
counter-bores 195 and lY9 ~Fig. 2) surrounding the opening
of the first passageway 182. The second passageway 184
extends from the bore 183 and terminates in an arcuate
aperture 185 in the transverse end wall 173. The first
passageway 182 extends longitudinally through the manifold
170~and transversely to the bore 183.
` Th2 mani~fold 170 has an exhaust chamber 190 with three
portlons, an entry portion 191, a central portion 186 and an ~
exit portion 198. Entry portion 191 is generally located ~ ;
forwardly of wall lao, exit portion 198 is located
rearwardly of that walI and central portion 186 ls generally
coextensive with such wall. Recessed portions 177 and 178
create converging side walls 192, which, along with the ~
'; ~ `
~ 21 ~ 2 5 8 7 62739-229E
inner surface of recessed portion 179, define entry portion ~;
191. Central portion 186 is generally in the form of a
parallelepiped although its upper surface is sllghtly
cylindrical. Exit portion 198 also has slightly diverging
side walls due to the recessed portions 177 and 178. Thus,
entry portion 191 is large and portions 186 and 198 are
substantially smaller. ;-~
A washer 193 and an O-ring 194 are respectively located
within the counter-bores 195 and 199 in the transverse
intermediate wall 180 (Fig. 2).
Referring to Fig~. 2 and 3, the manifold 170 i3 located `~
in the housing 20. The lugs 36 and 37 on the base member 30
and the lugs 87 and 8!6 on the cover member 80 mate
respectively with the opposed side recessed portions 177 and ' ` -
17a, while the abutment 45 on the inner surface 31 of the
base member 30 mates with ~he bottom recessed portion 179.
Further, the nose 143 of the screw 140 engages the washer
193 and the O-ring 194.
Referring to Fig. 11, the ratchet tool 10 further .`;~
comprisqs a valve assembly 200. The valve assembly 200 ~-
includes a one-piece elastomeric valve bushing 201 having a
valve seat 20?, a guide 203 and a sleeve 204 between the ,
~ . ~. . ....
valve seat 202 and the guide 203. The valve seat 2U2 has an
outer surface 208 with a circumferential groove 209, while
the guide 203 has an outer surface 210 with a - ~-
circumferential groove 211. The sleeve 204 has an aperture - ;`
205. A pin 206 having a head 207 extends through
the guide 203, the sleeve 204 and the valve seat 202. The
valve assembly 200 further includes a pair of O-rings 212 ;-
and 213, a valve ball 214 and a spring 215.
",
~ ~
~- .~. .
~ 21~2587 ~
, .
62739-229E
Fig. 2 depicts the manner in which the valve assembly
200 is mounted in the housing 20. The valve bushing 201 is
located ln the bore 183 of the manlfold 170 and the O-rings ~ ~`
212 and 213 are respectively located within the grooves 209
and 211 to provide a seal between the bushing 201 and the
bore 183. The force of the inlet air pressure in the first
pAss~geway 182 keeps the valve ball 214 seated agalnst the
valve seat 202. The spring 215 has one end dlsposed against
the guide 203 and an opposite end disposed against the head
207 of the pin 206.
To move the pin 206, the ratchet tool 10 further
comprises a paddle 216 including an arm 217, a shoulder 218
and an inner surface 219. The paddle 216 is pivotally
mo~inted to the outer surface 48 of the base member 30 by
- . . ' .
means of a pin 220 extending through the shoulder 218 which
. is received in the recess 57. The inner surface 219 abuts ` ~:. ~ the head 207 of the pin 206.
~ As described earlier, compressed air is delivered to
`~ ~ g~ the tool 10 via a hose (not shown) which is attached to the
nut 130. The air flows through the bore 134 of the nut 130
and the~bore 146 of the screw 140, through the passageway
182 in the manifold 170 and into the bore 183, forcing the
.:. valve ball 214 to seat on the valve seat 202. Thus, air is
prevented from flowing from the passageway 182 into the
. - . passageway 184.
~ Referring to Figs. 2 and 11, to turn on the ratchet
`~^t~ tool, the paddle 216 is pivoted towards the base member 30
: ;~ ` - causing the pin 206 to push the ball 214 away from the valveseat 202, thereby allowing air to flow from the passageway :
182, through the valve seat 202, through the aperture 205 in
~ ~ . ~
~ 2142587
- 62739-229E
'~''' ''`.'''`'''' ''
the sleeve 204, and through the passageway 184. The air
then flows through the aperture 185, and into the motor as ` ~l
to be descrlbed later.
As shown in Fig. 14, the ratchet tool 10 further
comprises a manifold gasket 230 including a circular
aperture 231 and an elollgated arcuate aperture 232. The
ga~ket 230 addltionally includes a circumferentlal edge 233
having a pair of recesses 234 and 235. As shown in Fig. 2,
the gasket 230 is disposed in the housing 20 against the
transverse end wall 173 of the manifold 170 such that the
aperture 232 communicates with t~le aperture 187. Although ~ s
not shown in any of~the figures, the recesses 234 and 235 of
the gasket 230 are respectively aligned with the recesses ~ ~:a^~
196 and~lg7 of the manifold 170 and the aperture 231 ~;
communicates with the aperture 185.
Referring to Figs. 3 and 15, the rachet tool 10 ~ ~i
additionally comprises generally cylindrical motor end y;
members;240 and 290~located at opposite ends of a motor 260.
As shown in Fig. 14, the member 240 includes an outer
sur~f~ace 2ql, an and~surface 242, and an oppoaed end surface ;~
243 tFig. 15)- Annular lips 245 and 246 protrude axially I=
from~the~end wall 242. An annular lip 248 (Fig. 15)
protrudes axially from the end wall~243. The member 240 .-
further includes a cylindrical passageway 249 and an
elongated arcuate passageway 250 extending between the end -~
walls 242 and 243. ~The mèmber 240 further includes axially
extending, communicating bores 251 and 252, the latter being - .
of smaller diameter. A bore 253 (Fig. 3) located adjacént ;~ }
the annular lip 248 extends lnto the end wall 243.
: ~
~ 17 ~ ~ `
`'" : ~``,'.'
~ 21~2~87 , ~:
62739-229E
Referring to Fig. 15, the generally cylindrical front
end member 290 includes an outer surface 291 and opposed end
surfaces ?92 and 293. An annular lip 295 extends rearwardly ;~
from the surface 292. An axially extending bore 296 (Flg.
3) is in the member 290 and is located near its periphery.
The melnber 290 has a central hole 298 and an annular bore
297 of larger diameter.
As shown in Figs. 2 and 15, the member 240 is disposed
in the housing 20 adjacent the gasket 230 and the manifold
170 and between the gasket 230 and the motor 260. The lips -~
245 and 246 (Fig. 3) respectively are located in recesses ;`~
234 and 235 of the gasket 230 and the recesses 196 and 197
of the manifold 170 to provide a secure and sealed
.~:: ,:
interconnection between the manifold 170, the gasket 230 and ;`
the member 240. The passageways 249 and 250 in the member
240 are respectively aligned with the apertures 231 and 232
in the`gasket 230 (Fig. 14) and resp ctively communicate `~
with the passageways 182 and 184 (Fig. 13) in the manifold
170.
Referring to Fig. 15, the motor 260 is of generally
standard configuration and includes a cylindrical liner 261
~having an outer surface 262. The liner 261 has a main
central portion 263 and short end portions 264 and 265 `
respectively at opposite ends of the central portion 263.
The end portions 264 and 265 are of slightly reduced i~
diameter so that an annular radial face 266 is defined -
between each of the end portions 264 and 265 and the central
,
portion 263. An axially extending bore 274 (Fig. 3) extends -;
partially into the liner 261 at each end thereof. The liner ,~`;;
261 includes an inner surface 267 defining a cylindrical
a
2142587
62739-229E
chamber. A rotor 268, including a shaft 270 and a plurality
of arcuate slots 275, is centrally located within the liner -`
26-. The shaft 2?0 has ends 271 and 272, the la~ter being
toothed. A circumferential recess 273 is near the end 272. ` : `~
A plurality of vanes 269 extend radlally outwardly from the ;` `
rotor 268. The vanes 269 have a generally flat upper
surface and a curved lower surface. They are disposed in
associated arcuate slots 275 and engage the inner surface `-
267 of the liner 261 along the length thereof. -
The annular lip 248 of the member 240 encircles the end
portion 265 of the liner 261. An O-ring 280 encircles the `~
end portion 265 and is disposed between the annuiar lip 248
and the radial face 266. A roll pin 282 (Fig. 3) extends
into the bore 274 in the liner 261 and the bore 253 in the `.
member 240 to align the motor 260 and the member 240. The
end 271 of t~le shaft 270 extends into the bores 251 and 252 -~
in the member 240. A ball bearing 283 is disposed in the
bore 251 and provides a journal ~or t11e end 271 of the shaft
270. `'
The lip 295 of the member 290 encircles the end portion
264 of the liner 261. An O-ring 281 is disposed between the
p 295 and the face 266 of ~lle liner 261. A roll pin 299 ~ ;
ig. 3) is disposed in the bore 296 of the member 290 and
the bore~274 of the liner 261 to align the member 290 and
the motor 260. The toothed end 272 of the shaft 270 extends
through the hnle 298~in the member 290. An O-ring 300 is
disposed in the recess 273 of the shaft 270. A ball bearing
~301 is disposed in the bore 297 of the member 290 and ~ ~ -~
provides a journal for the toothed en~ 272 of the shaft 270. . ~ ~-
In view of the journaling of the ends 271 and 272 ln the ~ ~ `
.,
2142587 ~ ~
62739-229E ~ ~
' ,,:
bearings 283 and 301 respectively, the rotor 268 is secured
in the liner 261 an~ is axially rotatable therain. `
The standard motor 260 operates in a well known manner.
Referri.ng to Flg. 22, alr enters the chamber defined by the ~ ;
llner 261 via the aperture 231 in the gaske~ 230 and Che
passageway 249 in the member 240 and inlet pocket 255. The
lnlet alr pressurizes the chamber 279 (indica~ed by cross
hatchlng) enclosed by the vanes 269~ ~lfferentlal pressures ``~ `~
actlng on differential exposed vane areas cause the rotor
263 to rotate in the liner 261. Because the liner 261 and
the rotor 268 (Fig. 3) are eccentric, the vanes 269 move in
and out of the associate~ slots ~75. Referring to Fig. 15,
the rotor 268 is concentric with the housing 20, but the
inner surface 267 of the liner 261 is off-center or
eccentric. As the rotor 268 and ~he vanes 269 rotate, air
initially trapped between adjacent pairs of vanes 269 is
vented (arrow 276) when exposed to the exhaust pocket 286,
then passageway 250 in the member 2~
Referring to Figs. 2 and 15, thq exhaust air flows
.. ~
througll the passageway 250 in the member 240, into chamber
190 of manifold 170, exit.ing the tool through opening 23. - ~`
; AJ described above, the manifold 170 thus provides air
andling features for both inlet and exhaust air.
-~ ~ The chamber 190 is sized to dampen llelmholtz ~ n~
frequencies oE the exhaust ,air. Helmholtz frequencies are
created by Lhe explosive rslease oE air from the exhausting
chamber of the air motor 260. The presencq of Helmholtz
frequencies is manifested by a 'poppiny" sound which
emanates from the interior of ~hq tool. The chamber 190 is
~ sized such that its volume is at least three times the ~
: ' ~'':
~ 20
~ 2 5 8 7 ` `--
62739-229E ;- ~ :
, ", ,. ,,., i.
volume of the exhaust chamber 287 (Fig. 22) in the motor
260. In an operative form of the invention, the ratio of , ,
the volume of exhaust chamber 287 in motor 260 to the volume
of chamber 190 was 5:1. It is aiso important that chamber ~-`
190 not be long and narrow. The narrowest part of the ` `
chamber is portion 186. In an actual embodiment, the ` `~`
central portion 186 had a height of about .25 inch, a width
of .4 inch and a length of about .375 inch. When the above . t--~
criteria are qatlqfied, the l~elmholtz fre~uencies are }
dampened and dissipated, thereby resulting in the ~ :
slgniflcant reduction in the level of the "popping' sound
emanating from the tool 10. ~ -
The exhaust air has a tendency to flow through the rear ~-~
end 172 of the manifold 170 and along the inner surfaces 31
and 81 respectively of the membQrs 30 and 80 and through the
gaps 112. This type of flow is undesirable because the
exhaust air would then come into contact with the user's ~-~
hand. The seal lS0 and the washer 160 are disposed between `~
the rear end 172 of the manifold 170 and the opening 23 in
the housing 20 such that exhaust air flowing through the ~ `-
chamber 190~ is forced to flow in the direction of arrow 277
(Flg.~2) along the inner surface of the seàl 150 and the
inner~surface of the wasller 160 and through the a~ertures
l64~therein. As a result, the exhaust air is prevented from
f1Owlng along the inner surfaces 31 and 81 respectivèly of
the~members 30 and 80.
The tool 10, as;shown ln Fig. 15, comprises a geor
reducer assembly 310 including an internal ring gear or
s~leeve 311 having an outer surface 312 and a toothed inner
surface 313. A tab 314 extends radially outwardly from the
, ~',.,
21 ~
. ! ~
214 2 ~ 8 7 62739-229E ;:
outer surface 312. The gear reducer assembly 310 further
includes three planet gears 31S, three planet gear pins 321,
and a carrier gear 316 (Fig. 2). Only one of the planet
gears 315 and one of the gear pins 321 are shown in Fig. 15.
Aq hown ~n Fig. 17, the carrier gear 316 has an outer
surface 317 and a toothed central opening 319. Three bores
320 are equiangularly spaced around the opening 318. Only
one of ~he bores 320 is shown in Fig. 17. Each of the bores
320 extend between opposite ends of the carrier gear 316.
~ The tab 314 is disposed within the recess 70 in the
base member 30 (Fig. 2). Each of the planet gears 315 is
disposed between the toothed end 272 of the rotor 268 and
the toothed inner surface 313 of the sleeve 311. The
~ carrier gear 316 is disposed in tlle housing 20 adjacent the
- end 272 of the shaft 270 and adjacent the planet gears 315.
A planet gear pin 321 is disposed in each of the bores 320 ~ r~
in the carrier gear 316 and the plane~ gears 315 (Fig. 2).
Referring to Figs. 3 and 17, the ratchet tool 10
urther comprises a cup washer 330 including a front end
331, a rear end 332 and an outer surface 333. The cup
washer 330 further includes a central opening at the front
end 331 defining a cylindrical surface 335. The cup washer ~;~
;`330 is disposed in the housing 20, with the front end 331
abutted against the lugs 34 and 35 of the base member 30 and
the lugs 84 an~ 85 of tl~e cover member 80 while the rear end
332 abuts against the sleeve 311. The gear carrier 316 is
centrally disposed within the interior of the cup washer
330,
~ fter assembly of the parts in the housing 20, the
screw 140 is tightened, causing the mànifold 170 to
: ` ~ ' , ~ :''. .
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22 ~
~ 214~587
62739-229E - 9~
: ...- ~:... -:
~:',.''''~,. .' '
," ,:- ., ''. .-',,;
move towards the front end 21 of the housing 2~. The axial
force is transferred to the gasket 230, the member 240, the ~`
motor liner 261, the member 290, ~he sleeve 311 and the cu~
washer 330, agalnst the lugs 34, 35, 84 and 35. As a
result, the members 240 and 290 are drawn towards the motor ;;
llner 261, and the O-rings 280 and 281 are squeezed axially
so as to be forced radially outwardly against the inner
surfaces 31 and 81 respectively of the members 30 and 80.
In thls manner, the motor 260 is securely mounted within the
housing 20 and ls lsolated thermally and vibrationally from ~ -~
the housing 20. Aiso, a seal is provided to prevent air
from flowing radially and between the motor liner 261 and ~ ~-
the members 24~U and 290.
Referring to Flg. 16, the ratchet tool 10 further -~
comprlses a bearing block 340 including an outer surface
343, a larger diameter cylindrical portion 353 and a
longltudinally extending bore 344 defining an inner surface ;~
- 345. The outer surface 343 is deflned by a smaller diameter
cylindrical portion 347 and conical portions 348 and 349
., : ,..
respectively at oyyosite ends of the cylindrical portion
; 347. The conical portions 348 and 349 diverge from the - 1 "
cylindrical portion 347. Protruding rearwardly from the
conical portion 349 is a generally cylin~.lrical collar 346.
Referring also to Fig. 17, the inner surface 345 has a
~ , larger diameter cylindrical portion 350 and a smaller
- diameter cylindrical portion 351 separated by a lateral face
;~` ` 352.~
~s is best seen in Fig. 3, the outer surface 343 of the
bearing block 340 cooperates with the outer surface 39 of -
~he lugs 34 and 35. More particularly, the cylindrical `
23 ;~
f= 21~2~87
62739-229E ~ :
portion 347 is adjacent to and slightly spaced from the
part-cylindrical portion 40 on each of t~e lugs 34 and 35
and the conical portions 348 and 349 mate respectively with :~
the part-conical portions 41 and 42 on each of the lugs 34
and 35. Referring to Figs. 3 an~ 8, the outer surface 343
also cooperates with the outer surface 89 of the lugs 84 and
85 to provide a rigid lnterconnection between the bearing
block 340 and the housing 20. More particularly, the
cylindrical portion 347 is ad~acent to and slightly spaced
from the part-cylindrical portion 90 and the conical
portions 348 and 349 mate respectively with the part-conical :~
portions 91 and 92 on each of the lugs 84 and 85..
As shown in Fig. 17, Lhe cylindrical portion 347 rests `~
against the ~edestals 44 and 94 respectively on the members .
30 and 80 to further provide a rigid interconnection between
the bearing block 340 and the housing 20. Fur~her, the
bearing block 340 extends into the central opening of the
cup washer 330 such t~lat the radial f ce 356 abuts the front ~-.
end 331 and the collar 346 engages the cylindrical surface
335.~ The ratchet tool 10 further comprises a crank shaLt
360 including a toothed surface 361 and a collar 363. The
collar 363 has a ràdial face 364. A finger j65 extends --~
axially outwardly from the face 364. The crank shaft 360 is
rotatably located within the bore 344 of the bearing block
340. The toothed surface 361 extends through the opening in
the cup washer 330 and engagès the toothed inne~ surface 319
of~the gear carrier 316. Since the toothed gear carrier 316
~is centrally disposed within the cup washer 330, and the
crank shaft 360 is centrally disposed within the opening in
the cup washer 330 due to the mating relationship between
I ~
~ 24
: . ~ ~
. . ~
2 1 ~ 2 ~ 8 7
62739-229E ~
,',',',' ,.' '- ' .
the bearing block 340 and the cup washer 330, proper `.
allgnment ~etween the gear carr.ier 316 and the crank shaft
360 is assured without the need of adjustment.
Referring to Fig. 17, the ratchet tool 10 further
comprises a crank stop washer 366 which surrounds the shaft
360 and is disposed against the end of the bearing block
340. A rlng 367 surrounds the toothed surface 36I and ahuts
the washer 366 and the gear carrier 316. ~he ring 367 .
prevents the shaft 360 from moving longitudinally in the `~
bore 394.
The ratchet tool 10 further comprises a pair of
bearings 370 and 371 which are supported and located in the
block 340. 'rhe bearings 370 and 371 are supported an-t
loc`ated such that the bearing 3?0 contacts the cylindrical
portion 350 of ~he inner surface 345 and the bearing 371 ~ .
contacts the cylindrical portion 351 of the inner surface
345
Reerring to Figs. 3 and 17, with ths particular `~
arrangement of the bearing block 340, an operating load Fl -:
applied `to the shaft 360 during fastener tightening or an `
-
operatlng load F~ appIied to the crank shaft 360 during
fastener removal is transferred to the bearings 370 and 371,
then to the bearing block 340, and~then to the housing 20
vla the lugs 34 and 35 and the lugs 84 and 85~ More
particularly, the force Fl causes the transfer oE
corresponding reaction loads F3 and F4 respectively to the
part-conical portions 41 and 42 respectively on tlle lugs 34
and 35, while the force F2 causes the tr.~nsfer of reac~ion
loads F5 and F6 respectively to the part-conical portions 41 - i
and 42 respectively on the luqs 34 and ~.5. When the members ~ - -
<.. ~ 's~
,~ " .:
~,-:,.' :''
:: ~'^` ~`'
^ 2142~87
~ 62739-229E
30 and 80 are mated together, the force Fl is transfesred in
a like manner to the part-conical portions 91 and 92
respectively on the lug~ 85 and ~4 while the force F2 ig
transferred in a like manner to the part-conical portions 91
and 92 respectively on the lugs 84 and B5.
Part-conical portions 41 on lugs 34 and 35 extend from
cylindrical portions 40 at an angle B. Part-conical portion ~ ;
348 on bearing block 340 extends from cylindrical portion
347 also at angle-B. Part-conical portions 42 on lugs 34
..
and 35 extend from cylindrical portions 40 at an angle A.
Part-conical portion 349 on bearing block 340 extends from - `;~
cylindrical portion 347 also at angle A. In the preferred
embodiment, angles A and g are equal and are 45. Referring
to Fig. 8, part-conical portions 91 and 92 on lugs 84 and 85
extend from cylindrical portio~l 90 respectively at angles
and ~. Referring ~ack to Fig. 3, the distance between the
applied loads Fl or F2 is maximized, thus minimizing the
size of the respective reaction loads F3 and F4 or F5 and F6
since~an applied load is a moment load.
As shown in Fig. 17, the ratchet tool 10 further
comprises a drive ring 372 including opposite sides 375 and
opposite arcuate ends 376 (Fig. 3). The drive ring 372 is
disposed on the finger 365.
-Referring-to Figs. 2, 3, and 18, the ratchet tool 10
further comprises a ratchet head 380 including a toothed `-
cy1indrical opening 381 and a part-cylindrical pocket 382.
The ratchet head 380 is disposed between the arms 60 and 99
and the drive ring 372 is located within the pocket 382.
The~rotor 268, via the gear reducer assembly 310, causes
rotation of the shaft 360 which causes the finger 365 and
.-:~:: ::
26
~ 21~2~87
62739-229E
the ring 372 to travel in a circular path. The recesses 69
and 106 respectively in the members 30 and 80 assure that
the ring 372 does not contact the inner surfaces of the arms
60 and 99 while the ring 372 travels in its circular path.
During one half of each cycle of rotation of the shaft 360
ln one dlrection, t~le ring 3~2 cause9 the head 380 to rotate ~`
ln one direction. For the balance of each cycle, the ring -~
372 causes the head 380 to rotate in the opposite direction.
- .- . :,
Referrlng to Figs. 2 and 18, the ratchet tool 10 ~ -
further comprises a drive body 390 includlng a central `-
portion 391, a head 392 extending from the central por~ion
391 and a square stud 393 extending from t~le head 392. The ~.
central portion 391 has a radially outwardly extending
~ shoulder 394 and an arcuate slot 395. A central bore 397 ~` -
: extends inwardly into the central portion 391. An adjacent
:~ ~.... ; ~:
bore 398 extends inwardly into the cen~ral portion 391 and ` -
~communicates with the slot 395. A counter-bore 404 -
surrounds ~tle opening of the bore 398. A shoulder 399 is
defined by the joinder of the central portion 391 and the
head 392. A groove 400 extends circumferentially around the '
outmr~surface of the head 392. A bore 401 extends '`'~
transversely through the stud 393. A spring 402 and a ball
403~arm disposed within the bore 401. The drive body 390
extends through the openings 63 and 102 respectively in the ~ -
arms 6U and 99 and through the opening 381 in the ratchet ~ :
head 380. ~,-
., :~ ,.. ~,
The tool 1~ further comprises a pawl 410 including
toothed ends 411 and 412. The pawl 410 is located in the ~".
slot 395. A pin 413 extending throùgh the bore 398 mounts `
:: . ~ ' ~
~ `~';, '-'~' ;'
-
^ 21~2587
62739-229E
the pawl 410 for rotation within the slot 395. An O-ring
420 is disposed in the counter-bore 404 (Fig. 19).
The ratchet tool 10 also comprises a knob 430 including ~`
an upper surface 431 and a lower surface 432. The lower
~urface 432 has a part-cyllndrical pro~ection 433 depending
and extending axially outwardly therefrom. A shaft 434
having an outer surface 435 extends axially outwardly from -`~
the projection 433. An ear 436 protrudes from the outer ~
surface 435 and is disposed ad3acent the projection 433. A - ;
bore 437 extends trans~ersely through the shaft 434 A
spring 438 and a plunger 439 are located in the bore 437.
The knob 430 is positioned above the drive body 390, the
shaft 434 is disposed within the central bore 397, the
plunger.439 abuts the pawl 410, and the ear 436 abuts the 0-
ring 420 ~Fig. 19).
Referring to Figs. 18 and 19, the knob 430 is rotatable
between fastener tightening and loosening positions. When -~
the knob 430 is in its fastener tightening position, the
plunger 439 engages the pawl 410 near one toothed end to
cause~the same to engage the toothed cylindrical opening 381
of the ratchet head 380. In this condition, the tool 10 can
be~usèd to rotate a fastener (not shown) in a clockwise
direction and to ratchet in a countèrclockwise dlrection~
;When the knob 430 is rotated to its fastener loosening
position, the plunger 439 engages the pawl 410 near the
other toothed end to cause the same to engage the toothed
cyllndrical opening 381. In this condltion, the tool I0 can :
be used to rotate the fastener in the counterclockwise
~direction and to ratchet in the clockwise direction.
28
2142~87
,~, ;.
67239-229E
': ~
During operation of the tool 10, the knob 430 has a
tendency to "self-reverse , i.e., a condition where
rotational forces on the plunger 439 during normal operation ~-
cause the knob 430 to reverse itself even though it had been
posltioned to tighten a fastener or vice versa. The ear
436, in combination with the O-ring 420, prevent~ the
inadvertent rotation of the knob 430 while the ratchet tool
is in use. As shown in Fig. lg, in order to move the ear
436 from positlon C in pllantom corresponding to tlle fastener '~ -
tlghtening position of the knob 430 to posltion D in phantom
corresponding to the fastener loosening position of the knob
430, the O-ring 420 must be cgmpressed as shown. That is
easy to do when the user manually rotates the knob 430, but
it cannot inadvertently occur during operation. ~-~
Referring to Figs. 2 and 18, the ratchet tool 10 -~
comprises an O-ring 440 disposed between the knob 430 and
the dri~e body 390. ln the preferred embodiment, the O-ring -~
has a circular cross-section. Tlle O-ring 440 is disposed ~ `
between and in contact with the lower surface 432 of the ` -~`
knob 430 and the shoulder 394 of the drive body 390.
Addltionally, the O-ring 440 encircles the projection 433
and abuts against at least a portion thsreof. The O-ring
440 is used to absorb shock in the event that the tool 10 is
,., -.
dropped and lands on the knob 430. The O-ring 440 isoJates ;~
the resultant shock and prevents it from being transferred '
to the drive body 390, the arms 60 and 99, or the housing
20. As a result, damage to the housing 20 in the form of
lmpact stresses is reduced.
The ratchet tool 10 further comprises a bushing 460 --
including a sleeve 461 having an inner surface 462 an~ an
~,~, .
29 -~
~ , ,, ,~,.,-.
~ 21~2587
62739-229E
outer surface 463. The inner surface 462 has a longitudinal
axis Y3 in substantial alignment with 1he longitudinal axis
Yl. Further, the bushing 460 includes a flange 464
extending radially outwardly from t.11e sleeve 461. The
flange 464 has a periphery 465.
As shown in Fig. 20, a plurality of serrations 466
extend circumferentially around the periphery of the flange
464. Each of the serrations 466 1~as a pair of surfaces 467
and 468 intersectlng to form a lvngitudlnal edge 469
extending a radial distance X Erom the longitudinal axis Y3.
~ecause of manufacturing tole~:ances, the radial distance X
which ~he edges 469 extend va~ies from edge to edge. As a
result of such variations, t.he lc1c1ls of the edges 4G9
defines a surface having a longi~tudinal axis n~t the same as
the axis Y3. Therefore, upon pless ~itting the bushing 460
into the opening 63, the axes Yl and Y3, are not aligned,
and the axes Yl and Y~ are not aligned. Therefor~, the
drive body 390 cannet be disposecl within the openin~s 63 and
102 wlthout adjustment.
To overcome this problem, the periphery of ths flange
464 is "turned" after the serrations 466 have been formed to
assure that the distance X which the edges 469 extsnd from
the longitudinal axis Y3 is equal for all edges 46'J. In ~`
this manner, and as `qhown in Fig; 20j the locus of the edges
469 defines a cylindrical surface 472 having a longitudinal
axis Y4 in substantial alignment with the axis Y3.
Tl1erefore, upon press fitting ~he ~ushing 460 to ths opening
63, the axis Y3 is substantially aligned Wit}1 ~he axis }'l~
In this manner, the drive bc,dy 390 can be disposed within
the openings fi3 and 102 wil:hout adjustment.
,
'~
i
^- 2 1 ~ 2 ~ 8 7
- . 67239-229E -.
" ~
Additionally, and as shown in Fig. 21, the serrations
466 may be tapered at an angle F with respect to the axis ~`
Y3. In a prePerred embodiment, the angle F i9 11. It is
understood that each of the edges 469 ls incllned at the :.; :;
same angle F with respect to the axis Y3. In thls manner, ~ ;-
the locus of the edges 469 define a conical surface having a
longltudlna~ axls identlcal to the axis Y4 in substantial `~
alignment wlth the axl~ Y3.
: As shown in Fig. 21, tl~e opening 63 has a mouth 470 : - :
tapered at an angle G measured with respect to the
longitudii~al axis Yl of the surface 64 to define a conical . ~
outer surface 471. In a preferred embodlment, tt)e angle G : ,;;.
is 11 since the taper of the moutll 470 matches the taper of `
~ the serrations 466. When t~)e bushillg 460 is press fit into - ~-
: : the opening 63, the inner surface 462 of the sleeve 461
abuts the drive body 390 while the surface 463 of the sleeve
461 tightly engages the surface 66 of the shoulder 65. The
; ~ ribs 67, which-are deformed upon press fitting, provide for
a secure fit between the arm 60 and ~he bushillg 460. In a ~.
flike manner, the serrations 466 of the flange 464 tightly
engage~the outer surface 64 of the opening 63. More
part1cularly, the edges 469 of the~serrations 466 en~age the
surface 64 to provide for a secure fit between the bushing
460 and the arm 60 when torque is transferred from the drive ~ ~`
body to the arm 60 . - ``~:`
i - Referring to Figs. 2 and 18, the ratchet tool 10
~further comprises a washer S00 disposed against the bushing - `
~ 460 and surroundinq the drive body 390. A retaining ring
;~ . 490 is disposed in ths groove 400 in the drive body 390. A
dlsk sprlng 480 is disposed between the was!ler 500 and the
.. . , . ~
'~'..` ''`,`,~'
'~ 21~87
62739-229E
retaining ring 490. The flange 464 of the bushing 460, the
washer 500, the spring 480 and the retaining rinq 490 are
disposed in the pocket defined by the shoulder 65 and the
cyllndrical surface 64 of the arm 60. The reta-lning ring
490 ls generally flush with the outer surface 61 of the arm
60.
When a conventional ratchet tool 10 i~ operated to
tlghten a fastener, there ls a tendency to oscillate it
during the ratcheting portion of each cycle if there is not
enough frlction or back stopping between the fastener and
the work piece. In the present invention, such slippage is
prevented by providing friction between the drive body 3gO
and the housing 20 as follows. The spring 480 exerts a
force against the retaining ring 490 and an opposite force
of equal magnitude against the washer S00 to bias the ~ `
shoulder 399 on the drive body 390 ayainst the shoulder 62
(Fiq. 6) on the arm 60 to provide friction between the drive
body 390 and the arm 60. Because shoulder 394 on drive body
:
]90 mates with shoulder 104 of arm 99, and because retaining
ring 490 and shoulder 65 of arm 60 are forced toward each
other (through wear washer S00, disk spring 480 and wear
bushing 460), arms 60 and 99 are restrained from any
! 5 :
tèndèncy to spread while ratchet tool 10 is operating.
While a particular embodiment of this invention has
, ~ ~
been described, it is understood that changes can be made in `~` `
' such embodiment without departing from the spirit or scope
~ - :
of the invention as defined in the claims.
32
