April 2, 1946- c. F.

voYTEcH - 2,397,634
AUTOMATIC TRANSMISSION
Filed OCC. 19, 1945 2 Sheets-Sheet 1

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April 2, 1946- c. F. voYTl-:CH 2,397,634
AUTOMATIC TRANSMISSION
Filed Oct. 19, 1945 2 Sheets-Sheet 2

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Patented Apr. 2, 1946 2,397,634

UNITED STATES PATENT OFFICE

2,397,634
AUTOMATIC TRANSMISSION
Charles F. Voytech, Chicago, Ill., assigner to
Borg-Warner Corporation, Chicago, lll., a cor
poration of Illinois
Application October 19, 1943, Serial No. 506,843
12 claims. (ci. 'x4-1895)
This invention relates to power transmitting ture in a two-path-and-direct-drive arrange
devices and particularly to infinitely variable ment, it being thought necessary however, prior
torque multiplying devices combined with gear to the present invention, to utilize av secondary
ing. In some of its forms and aspects this in planetary gear set to recombine the two paths
vention relates particularly to hydrodynamic de of power and to make possible the interchange
vices combined with gearing. f of functions. '
Although the smoothness with which a hydro Considering the foregoing desirable features in
dynamic torque converting device transmits a torque converter, and the desirable features ,
torque at infinitely varying ratio from a prede which a transmission designed for use with pres
termined maximum to unity is well known, it is 10 ent automobiles should have, the principal object
also well known that the eillciency of such a de of this invention is to provide a transmission in
vice likewise varies and seldom exceeds 90% corporating a hydraulic torque converter com
under the most favorable circumstances. This bined with gearing in a two-path relationship,
defect has caused designers to incorporate de with means for obtaining a reverse drive through
vices which by-pass the torque converter when the converter, said combination utilizing fewer
no torque multiplication is required and which gears than the devices heretofore proposed.
provide a parallel, more efficient path to be used A more specific object of this invention is to
with the converter when the latter is multiplying Vprovide a transmission wherein a hydraulic
torque. Thus an efficient arrangement which has torque converter and a planetary gear set are
been proposed comprises a hydraulic torque con 20 combined to furnish a two-path drive of infinite
verter combined with planetary gearing in such a ly varying torque ratios under heavy torque con
manner that for high torque demand part of ditions, a 100% mechanical direct drive for me-~
input power passes through the gearing directly dium torque conditions, and a 100% mechanical
to the driven shaft and the remainder passes overdrive for light torque conditions.
through the gearing to the converter and thence 25 Another object of this invention is -to provide
to the driven shaft, with means for locking up a transmission comprising a hydraulic torque
the planetary gearing to provide a 100% me converter combined with a single planetary gear
chanical drive between the input and output set with means for securing a reverse driver
shafts when no torque multiplication is required. through the combination as well as two-path
Modern automobile engines however are pref 30 forward drive.
erably provided with a 3.5 ratio rear axle if di A still further object of this invention is to
rect drive is the highest speed obtainable through provide a transmission of the torque converter
the transmission, or with a ratio of 4.25 if the top and planetary gear set type which will produce
speed is an overdrive. `Thus in the transmission the functions and ratios normally required of a
last referred to, a 3.5 axle ratio is required which 35 transmission in present day automobiles and
means that power must be transmitted through which nevertheless requires no complicated con
the converter at substantially all times during trol mechanism.
ordinary city driving and furthermore that the A still more specific object of this invention is
characteristics of the converter must be such to provide a simple control mechanism, incorpo
that it will convert torque over a very large rating both automatic and manual features, for
range of speeds both of which requirements are the combination torque converter and single
diiiicult to meet. To correct this deficiency there~ planetary transmission above described.
fore, an overdrive ratio should be supplied and These and other objects of this invention will
the rear axle ratio changed to 4.25, but this become apparent from the following detailed de
change would of course normally increase the scription when taken together with the accom
complexity of the transmission as well as the panying drawings in which:
number of parts to such an extent that it would Fig. 1 is a schematic diagram of the principal
render inadvisable the use of the innitely vari elements of this transmission;
able torque converter at all. Fig. 2 is a schematic diagram of the hydraulic
It is also known that a reverse drive may be and mechanical controls for the transmission
obtained through a converter without altering of Fig. 1;
the direction of drive of the pump element there Fig. 3 is a schematic wiring diagram of the
of, merely by interchanging the functions of the electrical controls for the said transmission; and
turbine and stator or reaction elements. It has Fig. 4 is a fragmentary development of a clutch
been proposed to incorporate this reversing fea taken generally along lines 4-4 of Fig. 1.
 2 2,397,634 ' "
Referring now to Fig. 1 for a detailed descrip to the intermediate position shown in Fig. 1
tion. ofthe invention, the transmission is com wherein it is free of both sets of teeth 44 and 45. , v
prised of a drive shaft I0 adapted to receive The three positions of sleeve 41 just described
power. from a prime mover such as an internal ' correspond to reverse, forward and neutral set
combustion engine (not shown), a driven shaft tings, respectively. A groove 49 is provided in-
-|| which passes completely through the trans sleeve 41 to receive a shift fork 55 (Fig. 2), said
mission and is piloted at I2 in drive shaft I0, a shift fork being pivoted in a lever 5| mounted on
hydraulic torqueconverter I3, a planetary gear a shaft 52 and adapted to be operated by an ex
set I4 and an automatic clutch I5 which dlscon- ` ternal lever 53, connected by a rod 54 to a lever
nects the transmission from the drive shaft I0 at 10 55 at the steering column. Said lever 55 is di
speeds corresponding to idling speeds of the prime rectly connected to a rod 56 which in turn is oper
mover. \ v
ated by a hand lever 51 positioned beneath the
Automatic clutch i5 is mounted on a flywheel I6 steering wheel (not shown) l of the vehicle.
having formed thereon a starting gear I1 and Second turbine stage 3| is also connected
drivably supporting a clutch cover |8. Supported through a one-way clutch 58 to intermediate shaft
in and driven by said cover I8 are weights I9 43, the one-way clutch being so arranged that in
which are adapted to pivot at 20 on housing |8 termediate shaft 43 may rotate faster than tur
`- to move a clutch pressure plate *2| toward flywheel bine 3|- but thel latter may not rotate faster than
|_6 thereby'frictionally driving a clutch driven the intermediate shaft.
disc 22. Said driven disc 22 may be of any well A clutch 59 is provided for connecting carrier 29
known ~construction, and may incorporate a vibra to ring gear 21 to lock up the gear setl in direct
tion dampening >device 23 in the hub section drive, which also in effect, connects drive shaft
thereof. Clutch cover I8 is also provided with a I0 with 4driven shaft |I. Said clutch 59 >is com
worm 24 which drives a worm wheel 25 and shaft prised of a set of clutch teeth 60 mounted on car
92 to supply rotative power to a pump the pur 25 rier 29, and a cooperating toothed annulus 6|
poses of which are to be described hereinafter. splined at 62 to a cylinder 63 rotatable with driven
Planetary gear set I4 is comprised of a sun gear shaft | |. Both sets of teeth have double chamfers
26, a ring gear 21, and one or more planet gears y as shown in Fig. 4. An abutment 64 is provided
28 meshing with the ringv and sun gears and at the end of cylinder 63 and a spring 65 is com
fmounted on a. planet carrier 29.~ Said carrier 30 pressed between said abutment and the teeth 6|
29 is driven directly by clutch driven disc 22. so as to tend to maintain clutch 59 in a disen
Hydraulic torque converter I3 is comprised of gaged position. An annular opening 66 is. pro
a vaned pump element 38, a first stage of turbine ' _ vided in a cylinder 63 in which is disposed an
vanes 3|, a second stage of turbine vanes> 32 annular piston 61. said piston being spaced from
> connected to the first stage 3| by a central web 35 annulus 6| by a spring 68 >which is stronger than
33, and a vaned reaction or stator element 34. Al spring 65. Shaft || is provided with a conduit
direct connection 35 is provided between pump 69 which connects annular opening 66 with an
element 30 and'sun gear >26 so that the two are exterior conduit 10 through which fluid under
constrained to operate together. Said connection pressure may be conducted to the opening to con
35 is provided with a brake drum 36 with which> 40 trol the operation of clutch 59.
a brake band 31 is adapted to cooperate to arrest Although clutch 59 provides a direct connec
the rotation of sun gear 26 and its associated ` tion between shafts Il) and II, the connection is
pump element30. The ilrst turbine stage 3| is dependent upon the operation of automatic
connected to a drum 38 with which'a brake band clutch I5 so that should flywheel I6 be rotated at
39 is adapted to cooperate to arrest the rotation 45 a speed less than the cut-in speed of clutch I5,
-of both the first and second stages 3| and 32 re clutch 59 would be ineffectual to connect driven
spectively, of the turbine elements. Reaction ele shaft II with drive shaft I0.
ment 34 is connectedthrough a one-way device In order to provide a connection between drive
. 40, such for example as the roller-and-cam mech shaft I0 and driven shaft || when clutch |5 is
anism frequently used as a freewheel device, `to 50 disengaged, a second positive clutch 1| is pro
a brake drum 4I with which a brake band 42 vided. This clutch is comprised of a set of teeth
is adapted to cooperate. One-way device 40,is 12 on drive shaft I0, a cooperating set of ratchet
vso arranged that it will not permit reverse rota teeth 13 on a slidable clutch-member 14 which
tion of reaction element 34 relative to brake drum is'splined at 15 to driven shaft || and is integral
4| but will permit such reaction element to ro 55 with an annular piston 16 concentrically mount
v tate freely forwardly with respect to said drum. ed with respect to shaft ||. -Said shaft || is
Ring gear 21 of planetary gear set I4 is con formed with an annular opening 11 to receive said
. nected to an intermediate shaft 43 which is con piston 16, opening 11 being in communication
centric with shaft | | and freely rotatable thereon. ,with a conduit 18 which connects said opening
' Said intermediate shaft 43 is provided at its right 60 11 with an external 'conduit 19 to control'the oper- _
hand end (Fig. l) with external splines 44. Re ation of clutch 1| . A spring 80 tends _to keep
action element 34 is also directly connected to in clutch v1| normally engaged so 'that when no uid
ternal splines 45 which are spaced from external under pressure is available, clutch 1| will auto
splines 44. Shaft || is likewise provided with ex matically engage and provide a -positive connec
ternal splines 46 on which is slidably mounted an tion between drive shaft A|| and drive shaft I8.
internally splined sleeve 41, said sleeve being pro The operation of the transmission thus far de
vided with external splines 48 at one end thereof scribed is as follows: -
which are adapted to mesh with internal splines Assuming that the transmission is tobe used
45 in one position of sleeve 41 to provide a direct in an automobile and that the automobile is
connection between reaction element 34 and standing still with the engine dead, that is, with
driven shaft II. Sleeve 41 is also adapted to- be drive shaft I0 stationary, automatic 'clutch I5 is
moved to -the left (Fig. 1) to engage external disengaged and clutch 1| is engaged by spring 80
splines 44 with its internal splines to provide a thus establishing a direct -connection between
directconnection between intermediate shaft 43 driven shaft || and drive shaft I0. Under these
and driven shaft I I. Sleeve 41 may also be moved 75 conditions should the engine starter fail to oper
 2,397,634 3
ate, the engine may nevertheless be started by tion so that it is in a forward direction rather
pushing the car since clutch 1I, provides -the than reverse and hence it will begin to rotate
-n_ecessary connection between shaft I,I and drive because it is liberated by the freewheel brake 40,
shaft I0. After the engine has been started and despite the fact that brake band 42 may still be
is idling, shift sleeve 41 may be made to assume tightened about brake drum 4I. _
either one of its three positions. It should be Under direct drive conditions through the tur
noted that said sleeve may be positioned in neutral bine I3, however, there is still a considerable loss
while the engine is being started by pushing the in efliciency and accordingly clutch 59 may be
car since theposition of sleeve 41 has no bearing operated by the controls hereinafter to be de
whatsoever upon the operation of clutch 1l. As 10 scribed to connect carrier 29 to driven shaft II.
suming, however, that sleeve 41 is in the neutral To operate clutch 59 fluid is introduced into an
position shown, the rotation of shaft I0 at engine nular opening 86 which urges piston 61 against
idling speed will also rotate flywheel I6, clutch toothed annulus 6I. The chamfered ends of the
cover I8 and the pump drive gears 24, 25 thereby teeth resist engagement until substantial synchro
providing fluid under pressure which is conducted 15 nism is effected and hence the net result of the
through conduits 19 and l18 to opening 11 to dis admission of fluid under pressure into opening 66
engage teeth 13 from teeth 12 against the action is to compress spring 88. Upon attaining syn
of spring 80. Thus clutch 1I is disengaged when chronism, as for example by the operator slowing '
the engine is idling and remains disengaged -as down the engine, spring 68 will snap the teeth of
long as fluid pressure is available in conduit 18. annulus 6I into engagement with clutch eth B0
To move the car in forward direction, manual and provide a one hundred per cent mechanical
shift lever 51 is rotated clockwise as viewed in direct drive between carrier 29 and driven shaft
Fig. 2, thereby shifting sleeve 41 to the left as II which, as previously stated, is the equivalent
shown in Fig. 1 through the intermediary of the of a direct drive between drive shaft I0 and driven
elements 50 to 51 inclusive. This connects inter 25 shaft II. '
mediate shaft 43 to driven shaft II. It is con ' It is contemplated that this transmission will
templated that clutch 59 is disengaged under be used with an automobile having a rear .axle
starting conditions. It is also contemplated that ratio of approximately 4.25 which has been stand
brake band 42 will be tightened upon drum 4I and ard in automobiles for many years~ At, say 30
brake bands 31 and 39 will be disengaged subse 30 to 60 miles an hour in direct drive with a 4.25
quent to the initial engagement of teeth 44 on axle the engine may be turning over faster than
intermediate shaft 43 with the internal splines on is necessary for the power delivered and hence
sleeve 41 but before the complete engagement of an overdrive is desirable. The overdrive is pro
these teeth with one another. The means by vided inthe present transmission as follows:
which these operations are accomplished will be 35 Without disturbing the setting of sleeve 41 or
described hereinafter. With drive shaft IIJ ro brake band 42, fluid pressure is removed from
tating above idling speed, clutch I5 will engage opening 66 so as to create an unbalanced condi
automatically by the movement of weights I9 tion tending to disengage clutch 59, and brake
outward and the drive will be transmitted from 31 is applied to brake drum 36 to arrest the rota
`clutch i 5 to carrier 29. Since ring gear 21 is 40 tion of sun gear 26. In the transition from direct
connected to intermediate shaft 43 and said shaft drive to overdrive `the direction of the torque
43 is directly connected to driven shaft II, the load on teeth GI will reverse and since said teeth
load of the vehicIe will resist the turning of ring 6I are already biased to disengaged position, as
21 and hence said ring gear 21 will function as 45 soon as the torque load has reached zero value
a reaction element, thereby causing sun gear 26 clutch 59 will be disengaged. With sun gear 26
to rotate in the same direction as carrier 29 but stationary and carrier 29 driving, ring gear 21
at an overspeed with respect thereto. Sun gear will be driven at an overspeed with respect to
26 being directly connected to pump element 30 carrier 29 and will therefore drive intermediate
of the torque converter I 3, said pump element will 50 shaft 43 and driven shaft II at an overdrive with
then energize the fluid in the converter, the ener respect to drive shaft I0. The arresting of the
gized fluid then impinging successively upon first rotation of pump element 30 also tends to arrest
turbine stage 3|, reaction element 34 and second the rotation of the remainder of the elements
turbine stage 32. Reaction element 34, however, 3|, 32 and 34 of the converter. This however
is held against rotation by means of one-way 55 creates no difficulty since one-way clutch 58 is
coupling device 40 and the previously tightened designed to permit intermediate shaft 43 to rotate
brake band 42 and hence the energy of the fluid ahead of turbine stage 3l and reaction element
will be absorbed in turning turbine elements 3| 34 is expressly designed to be statzonary.
and 32 in the same direction as pump element 30. Reverse is obtained by releasing brakes 31 and
The turning will be accompanied by increased 60 42, tightening brake band 39 upon drum 38
torque because of the action of stationary reac engaging clutch 59 so as to connect carrier 29
tion element 34, and this turning effort will be to ring gear 21 and thereby lock up planetary
transmitted through one-way clutch 58 to inter gear set I4, and by shifting sleeve 41 to the right
mediate shaft 43 where it joins the turning effort as shown in Fig. 1 to engage splines 48 with
impressed upon ring gear 21 by carrier 29 and 65 splines 45. Thus a direct drive is provided
planet pinions 28. Thus a two-path drive is ef through planetary gear set I4 to pump element
fected between drive shaft Illand driven shaft I I, 30, turbine elements 3l and 32 are held against
one of the drives being purely mechanical through rotation and reaction element 34 is connected
carrier 29, pinion 28, ring gear 21 and intermedi directly to the driven shaft I I. Under these con
ate shaft 43, and the remainder being hydraulic 70 ditions the functions of the turbine and reaction
through the converter as just described. As elements will be reversed and the reaction ele
driven shaft II gathers speed the torque ratio ment will tend to rotate backwardly, thereby
becomes closer to unity and torque converter I3 driving driven shaft II backward with it. Here
ceases to convert torque. At this stage the re again one-way clutch 58 breaks the drive between
action on reaction element 34 changes its direc 75 turbine elements 3|, 32 and intermediate shaft
 4 2,807,084
43 thus permitting the latter to rotate while the position is shown in dotted lines at I09a and full
former do not. Since the reverse drive is trans open throttle position is shown at |09b. The
mitted through a fluid. the transmission may be purpose of this arrangement is to permit a de
shifted into reverse when going down a very steep celeration ofthe engine while switch |0| is open
incline, and by regulating the speed of the en so as to break the circuit to solenoid 99 and at
gine a powerful braking action may be obtained the same time remove torque from the teeth o
which is more effective than coasting against the clutch 59. '
engine or coasting in gear. ' When shift sleeve 41 is in neutral position lever
Referring now to Fig. 2 for a description of 53 will assume the position shown in Fig. 2 and
the hydraulic controls, it is contemplated that 10 hence conduits 95 and 98 will be cut off from
brake bands 31, 39 and 42 will be controlled by pistons 83 and 85 and the fluid then behind
hydraulic pressure, brake bands 99 and 42 (cor these pistons will be vented through conduits ||0
responding to reverse and forward speed respec and Ill respectively. Assuming that ignition
tively) being applied by hydraulic pressure and switch |08 is closed and that the engine is turn
released by spring pressure, and brake band 31 15 ing over at idling speed it will be observed that
(corresponding to the overdrive control) being fluid under pressure is conducted through valve
normally applied by spring pressure and released 82 behind overdrive brake piston 8l to release
by hydraulic pressure. The details of the brakes brake band 351. To shift sleeve 41 to forward
are not shown since such details may be readily position, lever 51 is moved clockwise as shown
supplied by one skilled in this art. Thus brake in Fig. 2 thereby causing lever 53 to move counter
band 31 is released by a piston 8| which is con clockwise until teeth 44 and the internal splines
trolled by a valve 82, brake band 38 is tightened on sleeve 41 are in mesh. In completing the shift,
or applied to brake drum 38 by piston 89 which lever 53 contacts and then moves pin 88 causing
is controlled by a valve 99, and brake band 42 is valve 88 to be moved to the right, thereby closing
applied by a piston 85 which is controlled by a 25 od ventvopening ||| and opening pressure con
valve 88. Since brakes 39 and 42 are to be op duit 99 to piston 85. This causes the forward
erated in conjunction with the operation of shift brake 42 to be applied. After the vehicle moves
sleeve 41 their corresponding valves are so p0 f forward and the cut-in speed of governor |00 is
sitioned as to be operated by lever 53. In order reached, the circuit is completed through solenoid
to facilitate the engagement of the teeth of sleeve 99 and switches |04 . and |05. This energizes
41 with teeth 45 or 44 it is contemplated that solenoid 99 and causes it to move valve 89 down
brakes 39 and 42 will not be applied until after ward, thereby closing off the vent opening through
an initial engagement of the teeth on sleeve 41 conduit | i2, valve 84 and vent opening |I0, and
with teeth 44 or 45. Thus valve 84 is provided opening the pressure line 94 to the conduit 10 and
with a pin 81 which is contacted by lever 53 sub 35 clutch 59. Said clutch 59 will not engage until
stantially at the end of its movement toward re -the accelerator pedal |09 has been raised to
verse position and likewise valve 88 is provided relieve the torque as previously described. As
with a pin 88 which ls contacted near the end of suming however that accelerator pedal |09 has
the movement of lever 53 to its forward position. been so manipulated and clutch 59 is engaged,
Clutch 59 is controlled by a valve B9 under cer 40
tain conditions and by valves 99 and 84 under the transmission will be in direct drive as long
other conditions as will be hereinafter explained. as both switches |00 and |0| are closed. Should
The hydraulic circuits for the various condi a sudden emergency requiring increased torque
tions in the transmission of Fig. l are as follows: I
arise, however, accelerator pedal | 09 is depressed
Fluid is drawn from a sump through a conduit to wide open throttle position and then raised
90 by a gear type pump 9| which is driven by slightly to a point just short of closing switch
the shaft 92. The uid is then pumped under a |0| thereby deenergizing solenoid 99 and allow
pressure determined by a pressure control valve ing valve 89 to close off conduit 94 and reopen
l i4 into a conduit 93 having a branch 19 leading vent conduit || 2 to remove the pressure from
to clutch 1| and to the converter. It then passes 50 behind annular piston 61. The reversal of torque
through valve 82 into a conduit 91 having a which accompanied the slight release of accel
branch 94 leading to valve 89, a branch 95 leading erator pedal '|09 willpermit release spring 6'5 to
to valve 84 and a branch 96 leading to valve 98. disengage clutch 59 and the transmission will
Overdrive valve 82 is controlled by means of a then be in its two-path, high torque condition.
solenoid 98, and direct drive valve 89 is controlled 55 This condition may obtain as long as accelerator
by another solenoid 99. Referring to Fig. 3, sole pedal |09 remains sulhciently depressed to keep
noids 98 and 99 are connected in parallel with switch |0| open. To reestablish direct drive .the
respect to one another and in series with respect accelerator pedal is simply raised to close switch
to an electric governor switch |00 which is prefer-` |0| and also to again reverse the direction of
ably driven bydriven shaft Il so as to be re 60 torque, whereupon clutch 59 will be reengaged.
sponsive to vehicle speed. Said governor switch Assuming that the transmission is conditioned
|00 may be set to engage at any predetermined for direct drive operation and the operator wishes
speed in the range between 15 and 20 miles per to go into overdrive, he merely operates switch
hour. Direct drive solenoid 99 is also in series |03 to close the switch arms |02 and |04 thereby
with a normally closed switch 0| which is adapt 65 rendering inoperative the downshiftlng switch "
ed to be shunted by one arm |02 of a double pole |01 and also energizing solenoid 98. With sole
single throw switch |03 preferably mounted at noid 98 energized, valve 82 is -pulled up to close
the end of lever 51. The other arm |04 of switch oil pressure conduit 93 and open brake piston
|03 is in series with solenoid 98, both switches I 0| 8| to a vent opening ||3. Since overdrive brake
and |03 being in series with a battery |05 and 70 band 31 is released by fluid pressure and engaged
an ignition switch |06. A branch wire |01 sup by spring pressure the venting of the pressure
plies energy to the ignition circuit. Switch |0| behind piston 8| will result in the application of
has a pin |08 which is. adapted to be contacted brake band 31 to brake drum 38 thereby arrest
by an accelerator pedal |09 prior to the latter ing the rotation of sun gear 26. The movement
reaching full open throttle position. This prior 75 of valve 82 upward in response to ,energization
 2,397,634 5
of solenoid 98 dumps all fluid pressure in the and driven shafts, a power dividing differential,
system except that in conduits 19 and 93 and a reversible infinitely variable torque multiplying
hence also removes the fluid pressure from be- " device having input, forward and reverse connec
hind piston B1 of clutch 89 despite the fact that tions, and coupling means for selectively estab
solenoid 99 is still energized. Since the shift. lishing forward or reverse drive through the
from direct drive to overdrive is accompanied by mechanism, said coupling means including means
a torque reversal with reference to clutch teeth for connecting the differential to the drive shaft
60 and toothed annulus 6I of direct drive clutch and to the input connection for both forward
59, the mere application of overdrive brake 31 and reverse drives, means for connecting the dif
preceded by the venting of the pressure behind 10 ferential and output connections to the driven
drive clutch piston 61 will effect the release of shaft for forward drive, and means for locking
the direct drive and a shift into overdrive. While up the differential and connecting the reverse
in overdrive, manipulation of kickdown switch connection to the driven shaft for reverse drive.
IUI has no effect whatsoever upon the system. 3. A power transmitting mechanism as de
To change back to direct drive, as for example, to 15 scribed in claim 2, the coupling between the for
pass another vehicle, the operator opens switch ward connection and driven shaft being effective
|03 to deenergize solenoid 98. This restores pres only when power is- transmitted by the said for
sure behind pistons 61 and 8l thereby releasing ward connection, and means for establishing a
the overdrive brake, effecting a reversal of torque drive solely through the differential.
with respect to clutch teeth 80 and il and reen 20 4. A power transmitting mechanism as de
gaging said teeth upon their attaining substan scribed in claim 2, the coupling between the for
tial synchronism. ward connection and driven shaft being effective
To establish reverse drive, manual shift lever only when power is transmitted through the said
51 is moved counterclockwise as viewed in Fig, forward connection, and means for establishing
2 thereby effecting a clockwise movement of lever 25 an overdrive through the differential, said in
53 and its associated mechanism to shift sleeve finitely variable device being inoperative when
41 so as to engage teeth 48 with teeth 45, After the overdrive is established.
a partial engagement of said teeth, pin 81 of valve 5. A power transmitting mechanism compris
84 is contacted by lever 53 and the completion ing Vdrive and driven shafts, a power dividing
of the shift into reverse moves valve 84 to close 80 differential, a hydraulic infinitely variabletorque
off vent conduit H0 and open pressure conduit multiplying device having pump, turbine and
95 to piston B3. Through conduit II2 the pres reaction elements, and coupling means for selec
sure is also transmitted to valve 89 and conduit y tively establishing forward or reverse drive
10 to piston 61. Since the shift into reverse is through the mechanism, said coupling means
made while the car isstanding still and the including means for connecting the differential
engine is idling, there is no load on teeth 80 and to the drive shaft and to the pump element for
hence toothed annulus 6l may be forced into both forward and reverse drives, means for con
engagement with teeth 60 upon the mere appli necting the differential and turbine elements to
cation of pressure. This establishes a direct drive the driven shaft for forward drive, and means
"through planetary gear set ll and also applies for locking up the differential and interchanging
reverse brake band 39 to brake drum 38, the for the functions oi the turbine and reaction ele
ward brake 42 and overdrive brake 31 being dis ments for reverse drive, such that the reaction
engaged. The transmission is now in condition element is connected to the driven shaft in place
l for reverse operation. of the turbine element and the turbine element
45 acts as a reaction element.
If desired, the abovedescribed transmission may
be operated with the overdrive switch |03 in 6. In a power transmitting mechanism, drive
closed position at all times except when a down and driven shafts, a variable speed differential. -
shift is required. Direct drive would thus be an infinitely variable torque multiplying device
omitted in the upward shift and would be used havingninput and output connections, means in
only in emergencies. , 50 dependent of said differential and device for con
It is understood that the foregoing description necting the shafts for direct drive, means for
is merely illustrative of a preferred embodiment obtaining overdrive through `the differential, said
of the invention. The scope of the invention, differential being connectible to the drive and
driven shafts when overdrive is established
therefore, is not to be limited to the foregoing 55 therein,
description but is to be determined by the ap means for transmitting part of the power
' pended claims.
from the drive shaft through the differential to
I claim: ' the driven shaft and the remainder of the power
1. In a power transmitting mechanism, drive
through the differential to the torque multiplying
and driven shafts, a power dividing differential device, and one-way means for coupling said out
adapted to be connected to the drive shaft, means
put connection of said torque multiplying device
for transmitting a portion of the divided power to the driven shaft, said one-way device auto
matically disconnecting the torque multiplying
from the differential to the driven shaft, a re device from the driven shaft when the differen
versible infinitely variable torque multiplying
tial is conditioned for overdrive. v
device having input, forward and reverse connec 65 7; In a power transmitting mechanism, drive
tions, means coupling the input connection to and driven shafts, a variable speed differential
the differential, and selective means for estab comprising sun, ring, planet gears and a planet '
lishing forward or reverse drive between the driv gear carrier, a hydraulic torque converter com
ing and driven shafts including a one-way clutch prising pump, turbine and reaction elements,
for coupling the forward connection to the driven 70 means connecting the sun gear directly to the
shaft, means for coupling the reverse connection pump element, means connecting the carrier di
to the driven shaft, and means for locking up rectly to the drive shaft, an intermediate shaft,
the differential when the reverse connection is means directly connecting the ring gear to the
coupled to the driven shaft. ' intermediate shaft, one-way means connecting
2. In a power transmitting mechanism, drive 75 the turbine element to the intermediate shaft,
 6 . ,
_`a,sa7,os4 l A
selective means for arresting the rotation 'of action element, and two stages of turbine ,ele-~
either'the turbine element or the reaction ele ments, one stage being disposed on either side of
ment, clutch means for connecting the drive the reaction element and both stages being con
shaft to the intermediate shaft. and selective nected together, and coupling means for selec
means for connecting either the intermediate tively establishing forward and reverse drives
shaft or the reaction element to the driven shaft, through the mechanism, said coupling means in
whereby to provide a forward drive through the cluding means for connecting the diiferential to
mechanism when the reaction means is arrested the drive .structure and to the pump element for
and the intermediate shaft is connected to the both forward and reverse drives,_means for con
l driven shaft, or a reverse drive when the turbine 10 necting the differential and one stage of the tur
element is arrested, the drive and intermediate bine element to the driven structure and means
shafts are connected and the reaction element for holding the reaction element for forward
is connected to the driven shaft. ` drive, and means for holding the other stage of
8. .A power transmitting mechanism as de the turbine element and connecting the reaction
scribed in claim 7, and brake means for the sun 15 element to the driven structure for reverse drive.
gear to establish an overdrive through the plane 1l. A power transmitting device including drive
tary gear set when the selective means is condi and driven structures and a variable speed plan
tioned for forward drive. etary gear mechanism comprising drive, driven
9. ' A power transmitting device including drive and reaction elements, a clutch for connecting
and driven shafts and a variable speed planetary 20 two elements ofthe planetary gear mechanism
gear mechanism comprising drive, driven and re together for direct drive, a friction brake oper
action elements, a clutch for connecting two ele able upon one element for producing an overdrive,
ments of the planetary gear mechanism together fluid means for engaging the clutch, iiuid means
for 'direct drive, a friction brake operable upon for disengaging the brake, a valve controlling the .n
the third element for producing an overdrive, 25 fluid means for the clutch, a valve for controlling
fluid means for engaging the clutch, fluid means ` the fluid means for the brake, said valves being
for disengaging the brake, >a valve for controlling interconnected such that both said fluid means
the fluid means for the clutch, a valve for con are rendered inoperative when the brake is en,
trolling the fluid means for the brake, said valves gaged, a solenoid for each of said valves, a man
being interconnected such that both said uid 30 ually controlled switch in series with each sole-
means are rendered inoperative when the brake noid, a speed responsive switch, and a source of
is engaged, manually operated control means for electrical energy, said solenoids and` solenoid
each of said valves, the manual control means switches being in parallel with one another and
for the clutch valve being rendered ineffectual in series with the speed responsive switch and
when the control means_for the brake has been 35 source lof electrical energy,
operated, and speed responsive control means for 12. A power transmitting device as described
both valves, said speed responsive control means in claim 11, a switch in shunt with the direct
being in series with the manual control means. drive solenoid switch and means for closing said
10. A power transmitting mechanism compris.. switch when the overdrive solenoid switch is
ing drive and driven structures, a power dividing 40 closed.
diiferential, a hydraulic infinitely variable torque CHARLES F. VOYTECH. .
multiplying 'device having a.> -pump element, a re