U.S. patent number RE34,064 [Application Number 07/626,988] was granted by the patent office on 1992-09-15 for electric shift apparatus.
This patent grant is currently assigned to Automotive Products (USA) Inc.. Invention is credited to Keith V. Leigh-Monstevens, David C. Peterson, David F. Salzmann, Edward L. Tury, John G. Vander Poorte.
United States Patent |
RE34,064 |
Tury , et al. |
September 15, 1992 |
Electric shift apparatus
Abstract
An electric shift apparatus for use with a motor vehicle having
an automatic transmission. The apparatus includes a power module
adapted to be mounted on the housing of the transmission proximate
the transmission mode select lever and the transmission kick-down
lever and a control module adapted to be mounted in the passenger
compartment of the vehicle. The power module includes an electric
motor assembly drivingly connected to the free end of the mode
select lever and a solenoid drivingly connected to the free end of
the kick-down lever. The control module includes a plurality of
push button members corresponding respectively to the transmission
shift positions. An encoder device carried by the motor assembly of
the power module provides a constant coded signal indicating the
instantaneous position of the transmission mode select lever and
this coded signal is compared by comparator means in the logic of
the control unit with the selected shift position. The comparator
means generates a signal to the motor assembly to move the mode
select lever in a direction to achieve the selected shift position
and stops the motor assembly when the encoder signal received from
the power module matches the selected shift position indicating
that the selected shift position has been achieved.
Inventors: |
Tury; Edward L. (Brighton,
MI), Salzmann; David F. (South Lyon, MI),
Leigh-Monstevens; Keith V. (Rochester Hills, MI), Vander
Poorte; John G. (St. Clair Shores, MI), Peterson; David
C. (Walled Lake, MI) |
Assignee: |
Automotive Products (USA) Inc.
(Auburn Hills, MI)
|
Family
ID: |
26742684 |
Appl.
No.: |
07/626,988 |
Filed: |
December 13, 1990 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
62775 |
Jun 16, 1987 |
04790204 |
Dec 13, 1988 |
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Current U.S.
Class: |
74/335; 192/222;
73/866.1; 74/483PB |
Current CPC
Class: |
F16H
59/08 (20130101); F16H 59/20 (20130101); F16H
61/32 (20130101); F16H 61/0251 (20130101); F16H
61/18 (20130101); Y10T 74/20244 (20150115); Y10T
74/19251 (20150115) |
Current International
Class: |
F16H
59/08 (20060101); F16H 59/20 (20060101); F16H
61/28 (20060101); F16H 59/18 (20060101); F16H
61/32 (20060101); F16H 61/18 (20060101); F16H
61/02 (20060101); F16H 059/02 (); G05G
011/00 () |
Field of
Search: |
;74/335,336R,473R,473P,483PB,364,365 ;29/401.1
;73/866.1,117.2,117.3 ;192/4A |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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134646 |
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Mar 1986 |
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EP |
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59-50260 |
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Mar 1984 |
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JP |
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60-176829 |
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Sep 1985 |
|
JP |
|
863327 |
|
Mar 1961 |
|
GB |
|
832007 |
|
Apr 1990 |
|
GB |
|
Other References
Rolls Royce Manual, 2 pages, Aug. 1977. .
SAE Technical Paper 840448, Feb. 27,. 1984. .
SAE Technical Paper 831776, Nov. 7, 1983..
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Primary Examiner: Herrmann; Allan D.
Attorney, Agent or Firm: Krass & Young
Claims
We claim:
1. An electric shift apparatus for use with a motor vehicle having
an automatic transmission of the type including a mode select lever
and a kick-down lever positioned outside of the transmission
housing and mounted for pivotal movement at one end thereof about a
common axis, said apparatus comprising:
(A) a bracket adapted to be secured to said transmission housing
proximate said levers;
(B) first motor means mounted on said bracket and adapted to be
drivingly connected to the free end of the mode select lever;
and
(C) second motor means mounted on said bracket and adapted to be
drivingly connected to the free end of the kick-down lever.
2. An electric shift apparatus according to claim 1 wherein:
(D) said first motor means is an electric motor assembly.
3. An electric shift apparatus according to claim 2 wherein:
(E) said electric motor assembly includes a DC motor, a speed
reduction unit coupled to the output shaft of said DC motor, and
lever means interconnecting the output shaft of said speed
reduction unit to the free end of the mode select lever.
4. An electric shift apparatus according to claim 3 wherein:
(F) said lever means comprises a first lever connected at one end
thereof to said output shaft of said speed reduction unit and a
second lever connected at one end thereof to the other end of said
first lever and adapted to be connected at its free end to the mode
select lever.
5. An electric shift apparatus according to claim 4 wherein:
(G) said second lever includes two lever sections selectively
movable axially relative to each other to selectively vary the
effective length of said second lever.
6. An electric shift apparatus according to claim 4 wherein:
(G) said free end of said second lever includes a snap fitting for
a snap connection to the free end of the mode select lever.
7. An electric shift apparatus according to claim 2 wherein:
(E) said second motor means is a solenoid.
8. An electric shift apparatus according to claim 7 wherein:
(F) said bracket is adapted to be positioned generally vertically
at one side of the transmission housing in laterally spaced
relation to the transmission housing;
(G) said solenoid is mounted on the inboard side of said bracket so
as to be positioned between said bracket and said transmission
housing; and
(H) said motor assembly is mounted on the outboard side of said
bracket.
9. An electric shift apparatus according to claim 8 wherein:
(I) said motor assembly includes a DC motor, a speed reduction unit
coupled to the output shaft of said DC motor, and lever means
interconnecting the output shaft of said speed reduction unit and
the free end of the mode select lever.
10. An electric shaft apparatus according to claim 9 wherein:
(J) said DC motor is positioned on the outboard side of said
bracket;
(K) said speed reduction unit is positioned on the outboard side of
said bracket with its output shaft extending inboard to the inboard
side of said bracket; and
(L) said lever means is connected at one end thereof to said speed
reducer output shaft at the inboard side of said bracket.
11. An electric shift apparatus according to claim 10 wherein:
(M) said lever means comprises a first lever connected at one end
thereof to said output shaft of said speed reduction unit and a
second lever connected at one end thereof to the other end of said
first lever and adapted to be connected at its free end to the mode
select lever.
12. An electric shift apparatus according to claim 10 wherein said
second lever includes two lever sections selectively movable
axially relative to each other to vary the effective length of said
second lever.
13. An electric shift apparatus according to claim 12 wherein:
(O) said free end of said second lever includes a snap fitting for
snap connection to the free end of the mode select lever.
14. An electric shift apparatus for use with a motor vehicle having
an automatic transmission of the type including a mode select lever
and a kick down lever positioned on but outside of the transmission
housing and mounted for pivotal movement at one end thereof about a
common axis, said apparatus comprising:
(A) first control means accessible to an operator positioned in the
passenger compartment of the motor vehicle and operative to
generate a plurality of first electrical control signals;
(B) second control means accessible to an operator positioned in
the passenger compartment of the motor vehicle and operative to
generate a second electric control signal; and
(C) a power module adapted to be mounted on said transmission
housing proximate said levers and operative in response to receipt
of said first electrical signals to selectively move said mode
select lever and operative in response to receipt of said second
electrical signal to selectively move said kick-down lever.
15. An electric shift apparatus according to claim 14 wherein:
(E) said power module includes an electric motor assembly operative
in response to receipt of said first electrical signals to
selectively move said mode select lever and a solenoid operative in
response to receipt of said second electrical signal to selectively
move said kick-down lever.
16. An apparatus according to claim 15 wherein:
(F) said first control means includes a control module adapted to
be mounted in the passenger compartment of the vehicle and
including a plurality of mode select members operative to
respectively generate said first electrical control signals.
17. An apparatus according to claim 16 wherein:
(G) said second control means includes means operative to generate
said second electrical signal in response to total operator
depression of the accelerator pedal of the vehicle.
18. An electric shift apparatus for use with a motor vehicle having
an automatic transmission of the type including a mode select
.[.lever.]. .Iadd.element .Iaddend.to selectively shift the
transmission between a plurality of shift positions, said apparatus
comprising:
(A) a power module adapted to be mounted on the housing of the
transmission proximate the mode select .[.lever.]. .Iadd.element
.Iaddend.and including an electric motor assembly adapted to be
drivingly connected to the mode select .[.lever.]. .Iadd.element
.Iaddend.and encoder means operative to sense the shift position of
the transmission and generate an encoder signal representative of
the sensed shift position;
(B) a control module adapted to be mounted in the passenger
compartment of the vehicle and including a plurality of mode select
members accessible to the vehicle operator and corresponding
respectively to the transmission shift positions, and generator
means operative in response to operator actuation of each mode
select member to generate an operator signal representative of the
selected shift position; and
(C) comparator means receiving said encoder signal and said
operator signals, operative in response to receipt of an operator
signal differing from the received encoder signal to energize said
motor assembly in a sense to move the mode select .[.lever.].
.Iadd.element .Iaddend.to a position corresponding to the operator
signal, and operative in response to arrival of the mode select
.[.lever.]. .Iadd.element .Iaddend.in the selected position to
de-energize and brake said motor assembly.
19. An electric shift apparatus according to claim 18 wherein:
(D) said comparator means forms a physical part of said control
module.
20. An apparatus according to claim 19 wherein:
(E) said module includes a housing structure defining a front
face;
(F) each of said mode select members comprises a push button
mounted in said front face of said housing structure;
(G) said generator means is operative to generate a respective
operator signal in response to depression of a respective push
button; and
(H) said comparator means are positioned in said housing structure
rearwardly of said push buttons.
21. An apparatus according to claim 18 wherein
(D) said motor assembly comprises an electric motor, a speed
reduction unit coupled to the output shaft of said motor, and lever
means connected at one end thereof to the output shaft of said
speed reduction unit and adapted to be connected at the other end
thereof to said mode select .[.lever; .]. .Iadd.element
.Iaddend.and
(E) said encoder means includes an encoder member mounted on said
power module and selectively movable in response to actuation of
said motor.
22. An apparatus according to claim 21 wherein:
(F) said encoder member comprises an encoder wheel mounted on said
output shaft of said speed reduction unit.
23. An apparatus according to claim 22 wherein
(G) said speed reduction unit includes a housing defining a sealed,
interior chamber;
(H) said encoder wheel is positioned within said chamber; and
(I) said encoder means further includes a pick-up device carried by
said speed reduction unit housing and arranged to selectively
engage code indicia on said encoder wheel as said wheel rotates in
response to actuation of said motor.
24. An apparatus according to claim 23 wherein:
(J) said speed reduction unit includes a worm gear on the output
shaft of said motor and a worm wheel on the output shaft of the
speed reduction unit driven by said worm gear; and
(K) said encoder wheel is secured to a side face of said worm
wheel.
25. An electric shift apparatus according to claim 18 wherein:
(D) said control module comprises an operator access submodule
adapted to be mounted in an opening in the instrument panel of the
vehicle; and
(E) said comparator means comprises a logic submodule adapted to be
mounted in the passenger compartment of the vehicle remote from,
but electrically interconnected to, the operator access
submodule.
26. An electric shift apparatus according to claim 25 wherein:
(F) said mode select member is comprised of push buttons mounted in
the front face of said operator access submodule.
Description
BACKGROUND OF THE INVENTION
This invention relates to an electric shift apparatus especially
suited for use with a motor vehicle having an automatic
transmission.
Motor vehicle since their inception have required some manner of
gear change mechanism to satisfy the varying torque and speed
requirements encountered during the typical duty cycle of a motor
vehicle. For many years these gear change mechanisms were manual in
the sense that they required an operator input from a shift lever
or the like to effect each desired gear change ratio. More
recently, so called "automatic" transmissions have become popular
in which much of the shifting is done without operator input in
response to sensed speed and throttle opening parameters. These
automatic transmission typically include a mode select lever
positioned on the transmission housing and movable between a
plurality of selectively pivoted positions corresponding to a
respective plurality of shift modes within the transmission. The
mode select lever is pivotally moved between its several shift
positions by a cable or linkage mechanism extending from the mode
select lever to a suitable gear selector lever located in the
passenger commpartment of the vehicle. Various proposals have been
made in the past to eliminate the mechanical interconnection
between the driver operated lever and the mode select lever and
provide instead an electrical signal generated by a suitable action
on the part of the driver and transmitted electrically to some
manner of power means arranged to move the mode select lever. None
of these attempts to provide an electric shift mechanism for an
automatic transmission of a motor vehicle have met with any degree
of commercial success since they provided a slow or imprecise
shifting action and/or have generated excessive warranty and
maintenance costs.
SUMMARY OF THE INVENTION
This invention is directed to the provision of an electric shift
apparatus for the automatic transmission of a motor vehicle which
provides positive and precise shifting, which is amenable to ready
installation in the motor vehicle at the time of the original motor
vehicle manufacture, and which is reliable in operation even over a
long motor vehicle life.
The invention electric shift apparatus is intended for use with a
motor vehicle having automatic transmission of the type including a
mode select lever and a kick-down lever positioned outside of the
transmission housing and mounted for pivotal movement at one end
thereof about a common axis.
According to a feature of the invention, the electric shift
apparatus includes a power transmission module comprising a bracket
adapted to be secured to the transmission housing proximate the
levers; first motor means mounted on the bracket and adapted to be
drivingly connected to the free end of the mode select lever; and
second motor means mounted on the bracket and adapted to be
drivingly connected to the free end of the kick-down lever. This
arrangement provides a convenient, compact, bolt-on assembly for
providing all of the power means for performing all of the required
shifting functions at the transmission location.
According to a further feature of the invention, the first motor
means includes a DC electric motor, a speed reduction unit coupled
to the output shaft of the DC motor, and lever means
interconnecting the output shaft of the speed reduction unit to the
free end of the mode select lever. This arrangement provides a
convenient and efficient means for delivering the required torque
and pivotal movement to the free end of a mode select lever.
According to a further feature of the invention, the lever means
interconnecting the output shaft of the speed reduction unit and
the mode select lever comprises a first lever connected at one end
thereof to the output shaft of the speed reduction unit and a
second lever connected at one end thereof to the other end of the
first lever and adapted to be connected at its free end to the mode
select lever. This arrangement provides an efficient means of
transmitting power from the output shaft of the speed reduction
unit to the mode select lever, allows the various movement ratios
to be readily modified by changing the length of one or more of the
levers, and provide a compact envelope essentially lying totally in
the plane of the mode select lever.
According to a further feature of the invention, the second lever
includes two lever sections selectively movable axially relative to
each other to selectively vary the effective length of the second
lever. This arrangement allows the second lever to selectively
adjust to accommodate manufacturing tolerances.
According to a further feature of the invention, the free end of
the second lever includes a snap fitting for snap connection to the
free end of the mode select lever. This arrangement simplifies the
original vehicle manufacturing process by providing simple and
speedy connection as between the supplied power module and the
existing transmission hardware.
According to a further feature of the invention, the second motor
means is a solenoid arranged to actuate the kick-down lever. The
solenoid, in combination with the motor assembly actuating the
shift lever, provides positive and convenient control for all of
the required shifting movements at the transmission.
According to a further aspect of the invention, the electric shift
apparatus comprises first control means accessible to an operator
positioned in the passenger compartment of the motor vehicle and
operative to generate a plurality of first electrical control
signals; second control means accessible to an operator positioned
in the passenger compartment of the motor vehicle and operative to
generate a second electrical control signal; and a power module
adapted to be mounted on the transmission housing proximate the
mode select and kick-down levers and operative in response to
receipt of the first electrical signals to selectively move the
mode select lever and operative to response to receipt of the
second electrical signal to selectively move the kick-down lever.
This arrangement provides a power module which may be readily
mounted on the transmission and which operates in response to
receipt of the respective operator initiated signal to perform the
required shifting functions at the transmission.
According to a further feature of the invention, the power module
includes an electric motor assembly operative in response to
receipt of the first electrical signals to selectively move the
mode select lever, and a solenoid operative in response to receipt
of the second electrical signal to selectively move the kick-down
lever. The motor assembly and solenoid operate in combination to
effectively and efficiently control the transmission levers.
According to a further feature of the invention, the first control
means includes a control module adapted to be mounted in the
passenger compartment of the vehicle and including a plurality of
mode select members operative to respectively generate the first
electrical control signals. This arrangement allows the control of
the mode select lever to be provided by simply mounting the power
module on the transmission and mounting the control module in the
passenger compartment.
According to a further feature of the invention, the second control
means includes means operative to generate the second electrical
signal in response to total operator depression of the accelerator
pedal of the vehicle. This arrangement allows the kickdown lever to
be readily actuated in respose to total depression of the
accelerator pedal by the operator to generate the required passing
torque.
According to a further aspect of the invention, the electric shift
apparatus comprises a power module adapted to be mounted on the
housing of the transmission proximate the shift lever and including
an electric motor assembly adapted to be drivingly connected to the
mode select lever and encoder means operative to sense the shift
position of the transmission and generate an encoder signal
representative of the sensed shift position; a control module
adapted to be mounted in the passenger compartment of the vehicle
and including a plurality of mode select members accessible to the
vehicle operator and corresponding respectively to the transmission
shift positions and generator means operative in response to
operator actuation of each mode select member to generate an
operator signal representative of the selected shift position; and
comparator means receiving the encoder signal and the operator
signals, operative in response to receipt of an operator signal
differing from the received encoder signal to energize the motor
assembly in a sense to move the mode select lever to a position
corresponding to the operator signal, and operative in response to
arrival of the mode select lever in the selected position to
de-energize and brake the motor assembly. This arrangement provides
a ready and effective means of selectively actuating the motor
assembly and insuring that the mode select lever will be moved
positively to the shift position selected by the operator.
According to a further feature of the invention, the comparator
means forms a physical part of the control module. This arrangement
allows the comparator means logic to be incorporated within the
control module so that vehicle installation requires only
installation of the power module at the transmission and
installation of the control module in the passenger
compartment.
According to a further feature of the invention, the control module
includes a housing structure defining a front face, each of the
mode select members comprises a push button mounted in the front
face of the housing structure, the generator means operate to
generate a respective operator signal in response to depression of
a respective push button, and the comparator means are positioned
in the housing structure rearwardly of the push buttons. This
arrangement provides a convenient and compact package which may be
readily mounted in the passenger compartment of the motor vehicle
to provide operator push button transmission control and
simultaneously provide the comparator logic for coaction with the
encoder means to insure that the transmission is moved to the
selected position.
According to a further feature of the invention, the motor assembly
comprises an electric motor, a speed reduction unit coupled to the
output shaft of the motor, and lever means connected at one end
thereof to the output shaft of the speed reduction unit and adapted
to be connected at the other end thereof to the mode select lever,
and the encoder means includes an encoder member mounted on the
power module and selectively movable in response to actuation of
the motor. This arrangement provides a convenient means for
providing an encoder signal for use in determining the
instantaneous position of the transmission.
According to a further feature of the invention, the encoder member
comprises an encoder wheel mounted on the output shaft of the speed
reduction unit. This arrangement provides a convenient means of
providing the encoder signal in the context of the existing
structure of the motor assembly.
According to a further feature of the invention, the speed
reduction unit includes a housing defining a sealed interior
chamber, the encoder wheel is positioned within the sealed chamber,
and the encoder means further includes a pick-up device carried by
the speed reduction unit housing and arranged to selectively engage
code indicia on the encoder wheel as the wheel rotates in response
to actuation of the motor. This arrangement provides a convenient
means of providing the required encoder signal in the protected
sealed environment within the existing speed reduction unit.
According to a further feature of the invention, the speed
reduction unit includes a worm gear on the output shaft of the
motor and a worm wheel on the output shaft of the speed reduction
unit driven by the worm gear, and the encoder wheel is secured to a
side face of the worm wheel. This arrangement allows the encoder
wheel to be conveniently and compactly packaged within the speed
reduction unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of a motor vehicle
embodying the invention electric shift apparatus;
FIG. 2 is a fragmentary view looking in the direction of the arrow
2 in FIG. 1;
FIG. 3 is a perspective view of a power module employed in the
invention electric shift apparatus;
FIG. 4 is a fragmentary cross-sectional view taken on line 4--4 of
FIG. 3;
FIG. 5 is a fragmentary view taken in the direction of the arrow 5
in FIG. 3;
FIG. 6 is a cross-sectional videw taken on line 6--6 of FIG. 4;
FIG. 7 is a perspective view of a bracket employed in the power
module of the invention;
FIG. 8 is a fragmentary perspective view of a control module
employed in the electric shift apparatus of the invention;
FIG. 9 is a circuit diagram for the invention electric shift
apparatus;
FIGS. 10, 11 and 12 are views of an alternate form of encoder
mechanism for use in the invention electric shift apparatus;
FIG. 13 is a view of a modified lever assembly for use in the
invention electric shift apparatus; and
FIG. 14 is a view of a modified system for mounting the invention
control module in the vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention electric shift apparatus is seen schematically in
FIG. 1 in association with a motor vehicle of the type including an
instrument panel assembly 10 positioned within the passenger
compartment of the motor vehicle; a steering wheel 12 associated
with the instrument panel; an accelerator pedal assembly 14; and an
automatic transmission assembly 16 including a torque converter 18
and a transmission 20. Transmission 20 includes a mode select
.Iadd.element in the form of a mode select .Iaddend.lever 22 and a
kick-down lever 24 each mounted externally of the transmission
housing for pivotal movement at one end thereof about a common
axis. Specifically, kick-down lever 24 is fixedly mounted at its
lower end on a shaft 26 and mode select lever 22 is fixedly mounted
at its upper end on a tubular shaft 27 (see FIG. 2) mounted
concentrically on shaft 26. It will be understood that selected
pivotal movement of mode select lever 22 rotates tubular shaft 27
to operate internal devices within the transmission to position the
transmission in a plurality of transmission modes such as park,
neutral, drive, et cetera, and that pivotal movement of kick-down
lever 24 rotates shaft 26 to operate internal devices within the
transmission to shift the transmission to the next lower gear for
passing purposes or the like.
The invention electric shift apparatus broadly considered,
comprises a power module 28 and a control module 30.
Power module 28 is adapted to be bolted to the transmission in
proximity to levers 22 and 24 and includes a bracket 32, a motor
assembly 34, and a solenoid 36.
Bracket 32 may be formed as a die casting and includes a planar
main body portion 32a, lug portions 32b and 32c and a flange
portion 32d. Bracket 32 is readily bolted to the housing of
transmission 20 by bolts 38 passing through lugs 32b and 32c for
threaded engagement with threaded bosses 20a and 20b on the
transmission housing, and by a bolt 40 passing downwardly through
an aperture in a flange 32 on the transmission housing for threaded
engagement with a lug 20c on the transmission. Bosses 20a and 20b
and lug 20c are already present on a typical automatic transmission
housing and therefore need not to be especially provided to carry
out the invention.
Motor assembly 34 includes a DC electric motor 42, a speed
reduction unit 44, and a lever assembly 46.
Motor 42 is direct current and may be example have an output torque
rating of 200 inch pounds.
Speed reduction unit 44 is suitably secured to motor 42 and
includes a housing 48, a cover plate 50 having central hub member
50a, a worm gear 52 co-axial with the output drive of the motor 42,
a worm wheel 54 driven by worm gear 52, and an output shaft 56
driven by worm wheel 54 and journaled in cover plate 50 and in an
end wall 48a of housing 48.
Lever assembly 46 includes a first lever 58 secured by a nut 60 to
the free end of speed reduction unit output shaft 56, and a second
lever 60 secured by pivot means 62 to the free end of lever 58.
Lever 60 is a compound member and includes sections 60a and 60b.
Section 60b telescopically receives section 60a with a pin 60c
carried by section 60a guiding in a slot 60d in section 60b to
allow the two sections to move axially relative to each other to
vary the effective length of lever 60. The two sections may be
locked in any selected position of adjustment by a nut 63 carried
by pin 60c. The free end of lever 60 comprises a plastic snap
fitting 60e for snapping engagement with a ball fitting 22a on the
free end of mode select lever 22.
A modified version of compound lever 60 is shown in FIG. 13. In the
arrangement of FIG. 13, lever section 60b of compound lever 60 is
itself a compound member including a first member 60f and a second
member 60g. Member 60f is connected by slot 60d and pin 60c to
lever section 60a and defines a central cavity 60h. Member 60g
carries snap fitting 60e at its free end and is slidably received
at its other end in cavity 60h with a pair of matched coil springs
64,65 positioned in cavity 60h and engaging opposite sides of a
piston member 60i mounted on member 60g in cavity 60h.
The motor assembly 34 is mounted on the outboard face of the planar
main body portion 32a of bracket 32. Specifically, motor 42 is
mounted to the outboard face of bracket portion 32a by a bracket 66
and speed reduction unit 44 is mounted to the outboard face of
bracket portion 32a by a plurality of circumferentially spaced
bolts 68 passing through apertures 32e in bracket 32 and through
suitable apertures in speed reduction unit cover plate 50 for
engagement with threaded bosses 48b spaced circumferentially about
housing 48. In assembled relation, the hub portion 50a of cover
plate 50 passes through apertures 32f in bracket 32 to position
lever 58 on the inboard face of the bracket.
Solenoid 36 may comprise for example a pull type unit capable of
generating three pounds of pull and having a stroke of between
three-eighths and one-half inch. Solenoid 36 is secured to the
inboard face of planar main body portion 32a of bracket 32 by a
clamp 69. A cable 70 is secured to the plunger 71 of the solenoid
and a plastic snap fitting 72 is secured to the free end of cable
70.
Power module 28 further includes an encoder assembly 73 operative
to sense the shift position of the transmission and generate an
encoded signal representative of the sensed shift position.
Encoder assembly 73 include an encoder wheel 74 and a pick-up
device 76. Encoder wheel 74 may be formed for example of a suitable
plastic material and is positioned on a side face of worm wheel 54
within the closed and sealed interior chamber 78 defined by housing
48 and cover plate 50. Encoder wheel 74 includes a central aperture
74a passing speed reduction unit output shaft 56 and further
includes code indicia 80 provided on the exposed outer face of the
wheel and arranged along four arcuate tracks 80a, 80b, 80c and 80d
centered on the center line of the encoder wheel.
Pick-up device 76 includes a body member 82 mounting a plurality of
flexible resilient contact fingers 84 for respective coaction with
indicia tracks 80a, 80b, 80c and 80d. In addition to the four
fingers 84 for respective engagement with the four indicia tracks,
a fifth finger is provided to provide a ground for the system.
A lead 86 from motor 42 and a lead 88 from pick-up device 76 are
combined into a pin-type plug 90 and a lead 92 from solenoid 36
terminates in a pin-type plug 94.
Control module 30 is intended for ready installation in an opening
10a in instrument panel 10 by insertion of the module from the rear
of the housing and fastening of the module within opening 10a by
the use of several fasteners such as seen at 96. Module 30 includes
a housing structure 98 of general box-like configuration enclosing
an operator access or push button submodule 30a and a logic
submodule 30b.
Push button submodule 30a includes a plurality of .Iadd.mode select
members in the form of .Iaddend.push buttons 100 positioned in
vertically spaced relation in the front face 98a of the module
housing and corresponsding to the available transmission shift
modes. Specifically, buttons 100 include buttons corresponding to
park, reverse, neutral, over-drive, drive, second and first shift
positions for the transmission. Buttons 100 coact in known manner
with a printed circuit board 102 to generate suitable electrical
signals in response to respective depression of the buttons
100.
Logic submodule 30b include an electronic printed circuit board 104
suitably electrically connected to printed circuit 102 and suitably
mounting a first plurality of connector terminals 106 and a second
plurality of connector terminals 108. Connector terminals 106 coact
with a pin-type plug 110 at the end of a cable 112. Cable 112
includes plugs 114 and 116 at its remote end for plugging receipt
of plugs 90 and 94 so that plug 110 embodies the information from
leads 86, 88 and 92. Connector terminals 108 coact with a pin-type
plug 118. Plug 118 embodies the information from leads 120, 121,
122, 123, 124, 125 and 126.
Lead 120 is associated with a switch 130 sensing the open or closed
position of the driver's door of the vehicle; lead 121 is
associated with a switch 132 sensing the presence or absence of a
driver on the driver's seat of the vehicle; lead 122 senses the
open or closed condition of the ignition switch 134 of the vehicle;
leads 123 and 124 are connected to the negative and positive
terminals of the vehicle battery 135 with a suitable fuse 136 in
lead 123; lead 125 is connected to a speed sensor 137 which
provides information with respect to the instantaneous speed which
the vehicle is traveling; and lead 126 is connected with a switch
138 which is closed in response to movement of throttle lever 139
to its extreme open throttle position by a cable 140 connected to
known manner to the accelerator assembly 14 of the vehicle.
The invention electric shift assembly is delivered to the vehicle
manufacturer in the form of power module 28 and control module 30.
During the assembly of the vehicle, the power module 28 is mounted
on the transmission housing proximate the control levers 24 and 26
and the control module 30 is mounted in the instrument panel 10,
whereafter plugs 90 and 94 are plugged into plugs 114 and 116 and
plugs 110 and 118 are plugged into control module 30 to complete
the assembly of the invention electric shift apparatus.
The mounting of power module 28 on the transmission housing is
accomplished simply by passing bolts 38 through bosses 32b and 32c
for threaded engagement with transmission housing bosses 20a and
20b, passing bolt 40 through lug 32d for threaded engagement with
transmission housing lug 20c, and snapping snap fittings 60e and 72
respectively over ball fitting 22a on the free end of mode select
lever 22 and a ball fitting 24a on the free end of kick-down lever
24. As the lever assembly 46 is connected to the mode select lever,
lever sections 60a and 60b of lever 60 move telescopically and
selectively relative to each other to provide the precise effective
length of length 60 to allow positive snapping engagement of snap
fitting 60e over ball 22a irrespective of manufacturing tolerances,
whereafter nut 64 is tightened to lock the lever 60 in its precise
adjusted position.
Installation of control module 30 in instrument panel 10 is
affected simply by moving the control module from the rear of the
panel into the opening 10a and fastening the module in place by the
use of fasteners 96 or the like. Following the plugging of plugs 90
and 94 into plugs 114 and 116 and the plugging of plugs 110 and 118
into connector terminals 106 and 108, the system is operational and
ready for use.
Alternatively, in situations where space immediately behind the
facia of the instrument panel is limited, submodules 30a and 30b
may be designed and delivered as separate units with push button
submodule 30a mounted as previously described in opening 10a of the
instrument panel and logic submodule 30b mounted elsewhere in the
general environment of the instrument panel and connected to push
button submodule 30a in known manner by suitable wiring. For
example, as seen in FIG. 14, push button submodule 30a may be
mounted in instrument panel opening 10a and logic submodule 30b may
be mounted in the general area behind and below the facia of the
instrument panel 10 with the submodules interconnected by wiring
seen generally at 145.
In use various input signals, such as described above and
illustrated in FIG. 9, are supplied to logic chip 141, which may be
a programmable logic array or a gate array. Logic chip 141 is
configured to receive these input signals and generate the
necessary drive signals to motor 42 and solenoid 36 via buffer 142
for providing the selection of the desired gear. Firstly, the
various input signals are formed into a set of logic signals. These
logic signals include a set of signals whose state is selected by
the depressed push button 100; PARK, RVRS, NTRL, OVDR, DRVE, LOW1
and LOW2. One of these signals, corresponding to the desired gear
selected by the depressed push button is a logic "1" while the
other of these signals are a logic "0". Similarly the encoder
signal from encoder assembly 72 permits generation of a set of
logic signals PGP, PGR, PGN, PGO, PGD, PGL1 and PGL2 one of which
is active to indicate the present gear and the others of which are
inactive. The speed sensor input signal is formed into four logic
signals: MPH3 indicating a speed of greater than or equal to 3
miles per hour; MPH7 indicating a speed of greater than or equal to
7 miles per hour; MPH20 indicating a speed of greater than or equal
to 20 miles per hour; and MPH30 indicating a speed of greater than
or equal to 30 miles per hour. Each of these signals is active if
their condition is satisfied and inactive if not. Note that these
signals are cumulative; if the speed is over 30 miles per hour then
all will be active. Additional logic signals include DOOR
indicating the opened/closed status of the driver's door, SEAT
indicating whether or not the driver's seat is occupied, IGN
indicating the status of the ignition switch and ACC indicating
whether or not the accelerator switch 138 is closed.
Logic chip 141 serves to compare the inputs indicating the
depressed push button with the inputs indicating the present gear.
If they differ, then logic chip 141 generates an output signal to
motor 42 to rotate the motor unit the present gear matches the
selected gear. This process includes an indication of which shifts
are upshifts and which are down shifts according to the following
Boolean equations:
UP1=PGL1
UP2=PGL2 and Not(LOW1)
UP3=PDD and (Not(LOW2) and Not(LOW1))
UP4=PGO and (NRTL or RVRS or PARK)
UP5=PGN and (RVRS or PARK)
UP6=PGR and PARK
UPSHFT=UP1 or UP2 or UP3 or UP4 or UP5 or UP6
DNSHFT=Not(Not(UP1) and Not(UP2) and Not(UP3) and Not(UP4) and
Not(UP5) and Not(UP6))
Thus an up shift is required if the present gear is low1 (UP1), or
the present gear is low2 and low1 is not requested (UP2), or the
present gear is drive and neither low1 nor low2 are requested
(UP3), or the present gear is overdrive and either neutral, reverse
or park is selected (UP4), or the present gear is neutral and
either reverse or park is selected (UP5), or the present gear is
reverse and park is selected. A down shift is requested if none of
the intermediate states are satisfied.
Two motor control signals SHFTUP and SHFTDN are generated when the
signals ENABLE and OK2SHFT are active and the respective UPSHFT or
DNSHFT is active and shown below.
SHFTUP=ENABLE and UPSHFT
SHFTDN=ENABLE and DNSHFT
The ENABLE signal generally requires the desired gear to differ
from the present gear and certain safety conditions to be
satisfied. As shown below, ENABLE is inactive when the desired gear
is the same as the present gear.
ENABLE=GOLOW1 or GOLOW2 or GODRVE or GOOVDR or GONTRL or GORVRS or
GOPARK
These intermediate signals are formed as follows:
GOLOW1=LOW1 and Not(PGL1) and Not(MPH30)
GOLOW2=LOW2 and Not(PGL2) and Not(MPH20)
GODRVE=DRVE and Not(PGD)
GOOVDR=OVDR and Not(PGO)
GONTRL=NTRL and Not(PGN)
GORVRS=RVRS and Not(PGR) and Not(MPH7)
GOPARK=(PARK and Not(PGP) and Not(MPH3)) or (((Not(IGN) or
(Not(DOOR) and Not(SEAT))) and Not(PGN) and Not(MPH3)))
Thus the logic chip 141 does not permit a shift into low1 when the
speed is in excess of 30 miles per hour, and likewise does not
permit a shift to low2 if in excess of 20 miles per hour, to
reverse if in excess of 7 miles per hour, and to park if in excess
of 3 miles per hour. The second term in GOPARK automatically shifts
to park if the ignition is switched off (Not(IGN)), or if the door
is opened (Not(DOOR)) and the seat is empty (Not(SEAT)), the
driver's seat empty and the speed is not greater than 3 miles per
hour.
As soon as the instantaneous encoder signal transmitted by pick-up
device 76 matches the signal generated by the specific depressed
push button, the comparator logic of control module 10 functions to
deenergize and brake the motor so that the module select lever 22,
and thereby the transmission, is stopped precisely in the selected
shift position. If the lever 60 construction of FIG. 13 is
employed, springs 64,65 coact with piston 60i to ensure that the
internal detent controlled by lever 22 does not hang up on a crest
of the known roostertail in the transmission but that, rather, the
detent is moved to a precise shift position in which it is firmly
seated in a notch or valley of the roostertail.
If at any time the operator desires to downshift the transmission
as, for example, in a passing situation, the accelerator pedal 14
is fully depressed to close switch 138. A signal from the closed
switch 138 is transmitted to control module 30 by lead 126 where it
is amplified by a buffer device 142 carried by printed circuit 104
and transmitted in amplified form through lead 92 to solenoid 36
which is thereby energized to retract the plunger of the solenoid
and pivot downshift lever 24 in a counter-clockwise direction, as
viewed in FIG. 9, to effect the desired downshifting of the
transmission.
The invention system would also preferably include illumination
means for the push buttons 100 with the intensity of the
illumination controlled by the usual dash dimmer and with the
button corresponding to the selected gear being illuminated
brighter than the remaining buttons to provide a ready indication
of the instantaneous position of the transmission. An override push
button 143 is also provided as a part of push button submodule 30a.
Over-ride push button 143 allows the selection of the neutral shift
position when it is necessary for the seat to be empty and the
vehicle to be in neutral, for example, during vehicle tune-up,
vehicle car wash, et cetera.
The system also preferably includes a limp home switch 144 as part
of the push button submodule 30a. Limp home switch 144 is arranged
to manually jog motor 42 in the event of a system malfunction to
enable the vehicle to be driven home or to a repair facility.
An alternate form of encoder assembly is shown in FIGS. 10-12. In
this arrangement, the encoder assembly, rather than being provided
within the sealed cavity 78 of the speed reduction unit 44, is
provided as an independent unit 146 adapted to be fitted over the
mode select lever 22 and to move with that lever so as to
constantly sense the position of that lever and thereby sense the
shift position of the transmission.
Encoder assembly 146 includes a housing 148, an encoder member 150,
and a pick-up device 152.
Housing 148 may be formed of any suitable rigid material and
includes an outer wall 148a, an inner wall 148b, flange portions
148c, an aperture 148d in outer wall 148a, an aperture 148e in
inner wall 148b, and an arcuate slot 148f in inner wall 148b. In
this embodiment, the central shaft 26 on which the kick-down lever
24 is mounted is extended to provide a shank portion 26a, shoulder
portion 26b, and a threaded end portion 26c.
Encoder member 150 is arcuate and includes coded indicia 154
provided on tracks 154a, 154b, 154c and 154d generally
corresponding to tracks 80a, 80b, 80c and 80d on encoder wheel 74.
Pins 156 project from the face of encoder member 150 opposite the
face on which indicia 154 is provided.
Pick-up device 152 includes a body portion 158 and resilient
fingers 160 for coaction with the coded indicia on encoder member
150.
Encoder member 150 is positioned within the hollow interior 162 of
housing 148 with pins 156 passing sealingly through arcuate slot
148f, and pick-up device 152 is positioned on the inner face of
outer housing wall 148a with fingers 160 in coating relation to the
coded indicia on encoder member 150.
Encoder assembly 146 is fitted over shaft 26 with housing aperture
148e positioned on shank portion 26a, aperture 150a of encoder
member 150 positioned on shank 26a, outer wall 148a positioned on
shoulder 26b, and a nut 164 engaging threaded end portion 26c and
seating against the annular shoulder between shaft portions 26b and
26c so as to preclude axial displacement of encoder assembly 146
relative to shaft 26 but allow rotation of the shaft relative to
encoder assembly 146. Rotation of the encoder assembly is prevented
by engagement of flange portions 148c with suitable portions on the
transmission housing with kick down lever 24 disposed between
spaced flanged portions 148c and pivotal in the space provided
between the flange portions. Pins 156 snuggly engage the opposite
side edges of mode select lever 22 so that encoder member 150 moves
positively and precisely in accordance with the movement of the
mode select lever and so that the encoder signal picked up,
generated and transmitted by pick-up device 152 from the coded
indicia on encoder member 150 is always representative of the
precise shift position of the transmission.
The invention electric shift apparatus will be seen to have many
advantages. Specifically, the two modular assemblies minimize
component and inventory requirements; the ease of assembly of the
modules minimizes assembly plant labor; the power and control
modules may both be pretested prior to delivery to the vehicle
manufacturer with consequent improvements in reliability and
warranty costs; noise and vibration from the power train to the
passenger compartment is substantially minimized; the awkward and
intruding gear select lever is eliminated in favor of attractive
flush-mounted push buttons in the instrument panel of the vehicle;
and several important safety and convenience features are provided
such as automatic shifting to park when the ignition is shut off;
automatic prohibition of shifts that would be inappropriate in view
of the sensed vehicle speed and direction, and automatic movement
of the transmission to park in the event that the driver opens the
door and leaves the seat with the engine running and the
transmission in a position other than park. The invention electric
shift apparatus thus provides many comfort, convenience, and safety
advantages as compared to existing transmission control systems and
yet may be provided at a cost that is competitive with the existing
systems and with projected maintenance and warranty costs less than
the existing systems.
Whereas preferred embodiments of the invention have been
illustrated and described in detail it will be apparent that
various changes have been made in the disclosed embodiments not
departing from the scope or spirit of the invention.
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