Note: Descriptions are shown in the official language in which they were submitted.
d L~ L~ ~
~A~INE PROPULSION DEVICE
INCLUDING
GAUGE WITH ADJUSTABLE SENSITIVITY
BACKGROUND OF THE INVENTION
Tnis invention relates to mechanisms
provided for indicating the general angular position
of a marine propulsion device relative to a boat
transom and, more particularly, to trim sending
devices and trim gauges.
Attention is directed to the following
U.S. Patents:
Patentee Patent No. Granted
W. B. Lurie 2,681,435 June 15, 1954
J. R. Baskett 3,380,011 April ~3, 1968
W. A. Barden 3,564.476 Februa~y 16~ 1971
Kenneth W. Wise 3,601,082 August 24, 1971
Robert C. Schmiedel 3,641,965 ~ebruary 15, 1972
Lambrecht, et al. 3,722,456 .~arch 27, 1973
Lyle C. Pinkerton 3,750,617 August 7, 1973
Carpenter, et al~ 3,797,449 .~arch 19, 1974
Hager, et al. 3,834,345 Septem~er 10, 1974
Collis, et al. 3,844,247 October 29, 1974
Micnael Hentschel 3,848,185 November 12, 1974
Drabenko, et al. 3,886,448 May 27, 1975
~5 Hager, et al. 3,894,250 July 8, 1975
Lambrecht, et al. 3,929,089 December 30, 1975
Collis, et al 3,931,~84 January 13, 1976
J. A. Davi5 4,005,674 February 1, 1977
Woodfill, et al. 4,051,801 October 4, 1977
Wenstadt, et al. 4,318,699 .~arch 9, 19~2
Ludwig Lohner 4,364,733 Decem~er 21, 1982
Donald 0. West 4,420,741 December 13, 1983
--2--
Arthur R. Ferguson 4,449,945 May 22, 1984
E. I. Ballard 4,459,115 July 10, 1984
Lambrecht, et al. Re. 28,816 May 18, 1976
SUMMARY OF THE INVENTION
This invention provides a marine
propulsion device including a propulsion unit
steeraDle about a generally vertical axis and
tiltable about a generally horizontaL axis. The
propulsion unit includes a lower unit and a propeller
rotatably supported by the lower unit, a trim sending
device for indicating the general vertical angular
position of the propulsion unit, and including a
variable resistor adapted to ~e connected to ground,
and a trim gauge comprising a magnet suppor~ed for
pivotal movement, a fiest wire coil adjacent t~e
magnet and adapted to be connected to a power source,
a second wire coil magnetically adjacent and in
electrical connection With the first coil and adapted
to oe connected to ground, a lead electrically
connected Detween the first coil and the second coil
and electrically connected to the trim sending device
varia~le resistor, and means for varying the
sensitivity or tne gauge to the resistance of ~he
trim sending device variable resistor.
This invention also provides a gauge
including a magnet supported for pivotal movement, a
first wire coil adjacent the magnet and adapted to be
connected to a power source, a second wire coil
magnetically adjacent and in electrical connection
30 with the f irst coil and adapted to be connected ~o
ground, and means for varying the current sensitivity
of the gauge.
~.Z~t~9 ~2
_3_ 67363-709
In one embodiment, the sensitivity
varying means comprises a variable resistor in parallel
electrical connection with one of the first coil and
the second coil.
In one embodiment, the sensitivity
varying means comprises a variable resistor in parallel
electrical connection with the trim sending device.
The invention also provides a gauge
including a permanent magnet supported for pivotal
movement, a first wire coil adjacent the magnet and
having a first end adapted to be connected to a power
source and a second end, a second wire coil
magnetically adjacent the first coil and having a first
end adapted to be connected to ground independently of
an input signal, and a second end, means connecting the
second end of the first and second coils and adapted to
receive an input signal, and means for varying the
current sensitivity of the gauge.
The invention also includes a marine
propulsion device including a propulsion unit adapted
to be mounted on the transom of a boat so as to be
tiltable about a generally horizontal axis and movable
through a trim range wherein the angle of the
propulsion unit relative to the transom is less than a
predetermined angle and through a tilt range wherein
the angle of the propulsion unit relative to the
transom is greater than the predetermined angle, a trim
sending device including a first variable resistance
mechanically coupled to the propulsion unit and
respon~ive to movement of the propulsion unit about the
horizontal axis and operable to provide a variable
electrical effect indicative of the degree of rotation
of the propulsion unit about the horizontal axis, a
trim gauge responsive to the variable electrical effect
and including first and second coils operahle to
7~
-3A- 67363-709
develop a magnetic field having direction and magnitude
related to the ratio of currents through the first and
second coils, which trim gauge further includes a face
having thereon marked a trim segment including an end
and a tilt segment extending from the end, wh.ich trim
gauge further includes a pointer movable relative to
the face in response to the variable electrical effect,
which marine propulsion device further includes
sensitivity varying means for varying the response of
the trim gauge to the variable electrical effect and
operable to position the pointer substantially to the
end of the trim segment when the propulsion unit is
substantially at the predetermined angle such that the
pointer moves from the trim segment to the tilt segment
when the propulsion unit moves about the horizontal
axis from the trim range to the tilt range, and which
sensitivity varying means includes a second variable
resiskance connected to vary the ratio of currents
through the first and second coils independ~ntly of the
first variable resistance.
The invention also pxovides a trim
indicating system for use in conjunction with a marine
propulsion device includin~ a propulsion unit adapted
to be mounted on the transom of a boat or tilting
movement about a generally horizontal axis and movable
through a trim range wherein the angle of the
propulsion unit relative to the transom is less than a
predetermined angle and through a tilt range wherein
the angle of the propulsion unit relative to the
transom is greater than the predetermined angle~ which
trim indicating system comprises a trim sending device
including a first variable resistance adapted to be
mechanically coupled to the propulsion unit and
responsive to movement of the propulsion unit about the
horizontal axis for providing a varying electrical
7~
-3B- 67363-709
effect indicative of the degree oE rotation of the
propulsion unit about the horizontal axis, a trim gauge
responsive to the varying electrical effect and
including first and second coils operable to dPvelop a
magnetic field having direction and magnitude related
to the ratio of currents through the first and second
coils, which trim gauge further includes a face having
thereon marked a trim segment including an end and a
tilt segment extending from the end, and which trim
gauge further includes a pointer movable relative to
the face in response to the variable electrical effect,
which trim indicating system further includes
sensitivity varying means for varying the response of
the trim gauge to the variable electrical ef~ec~ and
operable to posit-ion the pointer substantially to the
end of the trim segment when the propulsion unit is
substantially at the predetermined angle such that the
pointer moves from the trim segment to the tilt segment
when the propulsion unit moves about ~he horizontal
axis from the trim range through the predetermined
angle to the tilt range, which sensitivity varying
means includes a second variable resistance connected
to vary the ratio of currents through the first and
second coils independently of the first variable
resistance.
The invention also provides a trim
indicating system ~or use in conjunc~ion with a marine
propulsion device including a propulsion unit adapted
to be mounted on the transom of a boat Eor tilting
movement about a generally horizontal axis and movable
through a trim range wherein the angle of the
propul~ion unit relative to the transom is less than a
7C3~
--3C-
predetermined angle and through a tilt range wherein
the angle of the propulsion unit relative to the
transom is greater than the predetermined angle,
which trim indicating system comprises a trim sending
device including a first variable resistance adapted
to be mechanically coupled to the propulsion unit and
responsive to movement of the propulsion unit about
the horizontal axis for providing a varying
electrical effect indicative of the degree of
rotation of the propulsion unit about the horizontal
axis, a trim gauge responsive to the varying
electrical effect and including first and second
coils operable to develop a magnetic field having
direction and magnitude related to the ratio of
currents through the first and second coils, which
trim gauge further includes a face having thereon
marked a trim segment including an end and a tilt
segment extending from the end, and which trim gauge
further includes a pointer movable relative to the
face in response to the variable electrical effect,
which trim indicating system further includes
sensitivity varying means for varying the response of
the trim gauge to the variable electrical e~fect and
operable to position the pointer substantially to the
end of the trim segment when the propulsion unit is
substantially at the predetermined angle such that
the pointer moves from the trim segment to the tilt
segment w}len the propulsion unit moves about the
horizontal axis from the trim range through the
predetermined angle to the tilt range, and which
sensitivity varying means includes a second variable
resistance connected to vary the ratio of currents
through the first and second coils independently of
the first variable resistance and is in parallel
electrical connection with the first variable
resistance.
The invention also provides a marine
propulsion device adapted for mounting on a variety
-3D-
of boats having transom angles whlch vary relative to
one another, which marine propulsion device includes
a propulsion unit adapted to be mounted on transom a
boat so as to be tiltable about a generally
horizontal axis and movable through a trim range
wherein the angle of the propulsion unit relative to
the transom is less than a predetermined angle and
through a tilt range wherein the angle of the
propulsion unit relative to the transom is greater
than the predetermined angle, a trim sending device
including a first variable resistance mechanically
coupled to the propulsion unit and responsive to
movement of the propulsion unit about the horizontal
axis and operable to provide a variable electrical
effect indicative of the degree of rotation of the
propulsion unit about the horizontal axis, a trim
gauge responsive to the variable electrical effect
and including first and second coils operable to
develop a magnetic field having direction and
magnitude related to the ratio of currents through
the first and second coils, which trim gauge further
includes a Eace having thereon marked a trim segment
including an end and a tilt segment extending from
the end, which trim gauge further includes a pointer
movable relative to the face in response to the
variable electrical effect, which marine propulsion
device further includes adjustable means for locating
the pointer substantially at the end of the trim
segment when the propulsion unit is substantially at
the predetermined angle so as to enable accammodation
by the gauge to variation in transom angles and so
that the pointer moves from the trim segment to the
tilt segment when the propulsion unit moves about the
horizontal axis from the trim range to the tilt
range, which adjustable means includes a second
variable resistance connected to vary the ratio of
currents through the first and second coils
independently of the first variable resistance.
~ ~7~3~2
-3E-
The invention also provides a trim
indicating system for use in conjunction with a
marine propulsion device adapted for mounting on a
variety of boats having transom angles which vary
relative to one another, which marine propulsion
device includes a propulsion unit adapted to be
mounted on a boat transom for tilting movement about
a generallY horizontal axis and movable through a
trim range wherein the angle of the propulsion unit
relative to the transom is less than a predetermined
angle and through a tilt range wherein the angle of
the propulsion unit relative to the transom is
greater than the predetermined angle, which trim
indicating system comprises a trim sending device
including a first variable resistance adapted to be
mechanically coupled to the propulsion unit and
responsive to movement of the propulsion unit abou-t
the horizontal axis for providing a varying
electrical effect indicative of the degree of
rotation of the propulsion unit about the horizontal
axis, a trim gauge responsive to the varying
electrical effect and including first and second
coils operable to develop a magnetic field having
direction and magnitude related to the ratio of
currents through the first and second coils, which
trim gauge further includes a face having thereon
marked a trim segment including an end and a tilt
segment extending from the end, and which trim gauge
further includes a pointer movable relative to the
face in response to the variable electrical effect,
which trim indicating system further includes
adjustable means for locating the pointer
substantially to the end of the trim segment when the
propulsion unit is substantially at the predetermined
angle so as to enable accommodation by the gauge to
variation in transom angles and so that the pointer
moves from the trim segment to the tilt segment when
the propulsion unit moves about the horizontal axis
-3F-
from the trim range through the predetermined angle
to the tilt range, which adjustable means includes a
second variable resistance connected to vary the
ratio of currents through the first and second coils
independently of the first variable resistance.
The invention also provides a trim
indicating system for use in conjunction with a
marine propulsion device adapted for mounting on a
variety of boats having transom angles which vary
relative to one another, which marine propulsion unit
includes a propulsion unit adapted to be mounted on a
boat transom for tilting movement about a generally
horizontal axis and movable through a trim range
wherein the angle of the propulsion unit relative to
the transom is less than a predetermined angle and
through a tilt range wherein the angle of the
propulsion unit relative to the transom is greater
than the predetermined angle, which trim indicating
system comprises a trim sending device including a
first variable resistance adapted to be mechanically
coupled to the propulsion unit and responsive to
movement of the propulsion unit about the horizontal
axis for providing a varying electrical effect
indicative of the degree of rotation of the
propulsion unit about the horizontal axis, a trim
gauge responsive to the varying electrical effect and
including first and second coils operable to develop
a magnetic field havlng direction and magnitude
related to the ratio of currents through the first
and second coils, which trim gauge further includes a
face having thereon marked a trim segment including
an end and a tilt segment extending from the end, and
which trim gauge further includes a pointer movable
relative to the face in response to the variable
electrical effect, which trim indicating system
further includes adjustable means for locating the
pointer substantially to the end of the trim
79 ~
-3&- 67363-709
segment when the propulsion unit is substantially at
the predetermined angle so as to enable accommodation
of -the gauge to variation in transom angles and so that
the pointer moves from the trim segment to the tilt
segment when the propulsion unit moves about the
horizontal axis from the trim range through the
predeter~ined angle to the tilt range, which adjustable
means includes a second variable resis~ance connected
to vary the ratio of currents through the first and
second coils independently of the first variable
resistance and being in parallel electxical connection
with the first variable resistance.
One of the principal features of the
invention is the provision of a gauge whlch includes
means for varying the current sensitivity of the gauge
so that the sensitivity of the gauge can be readily
adjusted. This permits the gauge to be individually
adjusted to best match the particular trim
characteristics oE whatever boat it is installed on.
For example, the sensitivity varying means permits ~he
gauge to be adjusted in the "field" so that the gauge
properly indicates full trim at the point for the
particular motor in its particular installation.
Further, the gauge can be used with different variable
resistor sending devices.
Another of the principal features of the
invention is the provision of such a gauge which is
easily adjustable.
Other features and advantages of the
invention will become apparent upon reviewing the
following description, the drawings, and the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FigO 1 is a schematic side viaw
representation of a marine propulsion device which
embodies various of the features of the invention.
--4--
Fig. ~ is an enlarged view of a portion
of the marine propulsion device including a trim
sending device which embodies various of the features
of the invention.
Fig. 3 is a cross-sectional view of the
trim sending device taken along the line 3-3 in Fig.
2.
Fig. 4 is a cross-sectional view of tne
trim sending device ta~en along the line 4-~ in Fig.
3.
Fig. 5 is a schematic rep~esentation of
a mechanism which is for measuring and visually
indicating generally the angular position of the
marine propulsion device shown in Fig. 1 and which
embodies various of the features of the invention.
Fig. 6 is a perspective view of a trim
gauge which embodies various of ~he features of the
invention~
Before an explanation of the invention
in detail, it is to be understood that the invention
is not limited in its application to the detail~ of
the construction and the arrangement of components
set forth in the fGllowing description or illustrated
in the drawings. The invention is capaDle o other
em~odiments and of being practiced and carried out in
vacious ways. It is also to De understood tnat the
phraseology and terminology employed herein is for
the purpose of description and not of limitation.
DESCRIPTION OF THE PREFERRED ~MBODIMENT
Illustrated in the drawings is a marine
propulsion device 10 ~hich includes a mechanism 14
for indicating the amount of swinging movement of or
7~ ~2
angular position of a propulsion unit 18 mounted on a
boat transom 22. In the illustrated construction,
the marine propulsion unit 18 is in the form of a
stern drive and the propulsion unit 18 is mounted on
the ~oat transom 22 by mounting means in the form of
a gimbal housing areangement 24. The gim~al housing
arrangement 24 comprises a transom housing 26
connected to the boat transom 22, and a gimbal ring
27 mounted on the transom housing 2~ for horizontal
swinging movement. The propulsion unit 18 is
pivotally connected to the gimbal ring 27 for
vertical swinging movement. Accordingly, the gimbal
housing arrangement 24 permits swinging of the
propulsion unit 18 horizontally a~out a generally
vertical axis for steering, and swinging of the
propulsion unit 18 vertically a~out a generally
horizontal pivot axis 23 for trimming and tilting.
Means is ~lso provided in the form of a
tilt and trim cylinder assembly 28 connected between
the gimoal ring 27 and tne propulsion unit 18 for
swinging the propulsion unit 18 vertically relative
to tne boat transom 22.
The propulsion unit 18 also includes a
lower unit 29 rotatably supporting a propeller 30,
and means (not shown) for rotating the propeller 30.
Although other constructions can be
employed in other em~odiments, the indicating
mechanism 14 (see Fig. 5) provides a visual
indication of the general angular position of the
propulsion unit 18 rela~ive to the ~oat transom 22.
~ore particularly, the indicating mechanism 14 shows
the general angular position of the propulsion unit
18 as the propulsion unit 18 swings vertically
relative to the boat transom 22 througn a first
~2'~'7~
angle. The mechanism 14 then indicates the
propulsion unit 18 is located at some angular
position beyond the first angle~ In tnis particulac
embodiment, the first angle i5 a trim angle or range,
and movement of tne propulsion unit 18 beyond the
trim angle is referred to as the tilt angle or range
of the propulsion unit 18. Movement of the
propulsion unit 18 through the trim range g~nerally
provides for raising and lowering of the ~ow of tne
boat to change the attitude of the boat while under
power, and movement of the propulsion unit 18 througn
the tilt angle raises the propulsion unit 18 out o~
the water for service or storage.
The indicating mecnanism 14 includes
means in the form of a trim gauge 34 (see Figs. 5 and
6) for producing a general visual indication of the
angular position of the propulsion unit 18, and
signal sending means in the form of a trim sending
device 3~ for producing a signal operaole to control
the trim gauge 34.
More particularly, as illustrated in
Figs. 2 through 5, the trim sending device 38
comprises a housing 42, and a variable resistor 46
(see FigO 4) including a resistance element S0
supported within the housing 42 and naving an end 54,
a fixed resistor 62 in parallel electrical connection
witn the variable resistor 46, and a wiper 58
supported within the housing 42 for pivotal movement
along the resistance element 50. Although other
constructions can be used in other em~odiments, the
housing 42 is mounted on the gimbal ring 27 in spaced
reLation from the generally horizontal pivot axis 23.
The trim sending device 38 also
includes moving means adapted to ~e responsive to the
7~
swinging movement of the propulsion unit 18 for
moving the wiper 58 along the resistance element 50
as the propulsion unit 18 moves througn the trim
angle, and for moving the wiper 58 beyond the
resistance element end 54 as the propulsion unit 18
moves beyond the predetermined angle. Although other
constructions can ~e used in other embodiments, such
moving means comprises a lever 66 (see Figs. 2 and 3)
pivotally mounted on the housing 42. Tne wiper 58 is
connected to the lever 66 for common pivotal movement
so tnat the wiper 58 moves along the resistance
element 50 as the lever 66 pivots relative to the
trim sending device housing 42. More particularly,
as illustrated in Figs. 3 and 4, a pin 70 pivotally
mounts one end of the lever 66 on the housing 42 and
connects tne lever 66 to the wiper ,8.
In other embodiments (not shown)~ the
wiper 58 can be connected at the pivot axis 23 to one
of the propulsion unit 18 and the gimDal ring 27, and
the resistance element 50 can be mounted on the other
of the propulsion unit 18 and the gim~al ring 27. An
advantage of having the housing 42 spaced from the
pivot axis 23 and of using the lever 66, nowever, is
that a small amount of propulsion unit swing results
in a greater amount of swing of the lever 66 and
wiper 58, thereDy increasing the amount of change in
resistance produced ~y a change in the angle of the
propulsion unit 18. As a result, the sending device
38 is more sensitive to propulsion unit movement~
As illustrated in Fig. 2, the moving
means also includes means opera~le ~etween the wiper
58 and the propulsion unit 18 for moving the wiper 58
along the resistance element 50 in an amount which is
variaDly proportional to the amount of swinging
L~7 9 ~ ;~
movement of tne propulsion unit 18. More
particularly, the variable proportional moving means
comprises a curved camming surface 78 on the
propulsion unit 18 adjacent the free end 74 of the
lever 66, and means for ~iasing the free end 74 of
the lever 66 into contact with the curved camming
surface 78 so that the lever 66 pivots in a manner
determined by the curved camming surface 78 as the
propulsion unit 18 swings. More particularly, as
illustrated in Figs. 2 and 3, the biasing means is in
the form of a torsion spring 82 concent~ic with tne
pin 70 and having a first end 86 fixed on the trim
sending device housing 42, and a second end 90 which
engages tne lever 66 to rotate the lever 66 clockwise
wnen viewed as in FigsO l and 2.
The profile of the curved camming
surface 78 can be snaped to provide a linear or
nonlinear relationship between the amoun~ of wiper
movement and vertical movement of the propulsion unit
18, or to alter the multiplication effect on the
amount of wiper movement, or to specifically correct
for nonlinearites in the indicating mechanism 14 so
that the trim gauge indications are directly
proportional to tne angle of the propulsion unit 18.
Means is also provided for engaging the
leve~ 66 after the lever 66 and wiper 58 swing
througn the first angle so that the free end 14 of
the lever 66 is positioned to be en~aged by the
curved camming surface 78 when the propulsion unit 18
swings back into the trim range. In the illustra~ed
embodiment, this means is in the foem of a stop 94
which is located on tne housing 42 and which engages
a tao (not shown~ on tne lever 66 after the lever 66
swings through the trim range.
~Z47~4~2
The operation of the trim sending
device 38 is therefore as follows:
As the lever 66 and wiper 58 pivot With
the propulsion unit 18 tnrough the trim range, the
wiper 58 moves along the length of the resistance
element 50. As the wiper 58 moves along the
resistance element 50, the resistance of the variable
resistor 46 changes in a manner determined by the
type of resistance element used. In some
constructions, the change in resistance will ~e a
linear function of the amount of wiper movement, and,
in other constructions, the cnange in resistance will
~e a nonlinear function of the amount of wiper
movement.
The amount of movement of the wiper 58
at a particular time is dependent upon the shape of
the curved camming surface 78. In other words, the
curved camming surface 78 allows for great or small
amounts of wiper movement with each amount of
propulsion unit swing. The provision of the camming
surface 78 therefore pecmits one to cnose a desired
relationship ~etween the amount of propulsion unit
swing and the resulting cnange in the resistance of
~he variable resistor 46. One such desired
r~lationsnip is to have the change in resistance,
when the sending device 38 is connected to tn~ trim
gauge 34, produce a change in the visual indication
of trim angle which is directLy proportional to the
actual change in the trim angle of the propulsion
unit 18.
By having the variable resistor 46 and
the fixed resistor 62 in parallel electrical
connection, the following result is achieved. The
resistance of tne parallel circuit is equal to the
94;~
--10-
inverse of one over the resistance of the variabLe
resistor 46 plus one over the resistance of the fixed
resistor 62. The variable resistor 46, when at its
lower resistance, has some small value. As the
variable resistor's resistance increases, the total
resistance of the parallel circuit increases. At the
point where the variable resistor's wiper 58 leaves
the end 54 of the resistance element 50, the total
resistance provided by the parallel circuit changes
in a discontinuous manner and increases
significantly. As a result, when the parallel
circuit is connected across a voltage source, the
discontinuous change in tne resistance causes a
discontinuous change in current passing through tne
parallel circui~. This change in resistance, when
the trim sending device 38 is connected to the trim
- gauge 341 produces a discontinuous visual indication
of the propulsion unit 18 leaving tne trim range and
entering the tiLt range. This visual indication
serves to alert an operator of means for swinging tne
propulsion unit 18 to discontinue swinging the unit
18 unless tilting of the unit 18 is desired.
When the propulsion unit 58 is in the
tilt range, the resulting resistance of the parallel
circuit is equal to the value of the ~ixed resistor
62. Since the manufacturing tolerance of a fixed
resistor is ~etter than that of a varia~le resistor,
the resistance of the sending device 38 when tne
propulsion unit 18 is in the tilt range is more
predictable. Accordingly, when the propulsion unit
18 is in the ~ilt range, a more predicta~le visual
indication is o~tained.
In other em~odiments~ the lever 66 can
engage a switch (not snown) whicn is on~ the nousing
~2'.~7~
~ 67363-709
42 and which is el~ctrically connected between the
fixed resistor 62 and the variable resistor 46 to open
the connection therebetween as the propulsion unit 18
travels beyond the predetermined angle. The switch
would thus serve to remove the variable resisto~ 46
from the parallel circuit in a manner similar to the
wiper 58 leaving the resistance element 50.
As illustrated in Figs. 5 and 6, the trim
gauge 34 comprises a support in the form of a housing
98, and a magnet 102 supported within the housing 98
for pivotal movement about an end thereof, and a first
wire coil 106 adjacent the magnet 102 (as shown
schematically in ~ig. 5) and in a plane adjacent the
magnet 102 and adapted to be connected to a power
source, such as the illustrated battery 107. The trim
gauge 34 also includes a second wire coil 110
magnetically adjacent and in electrical connection and
in ~he same plane with the first coil 106 and connected
to ground. More particularly, the second coil 110 is
in the form of a first coil portion 111 connected to
ground, and a se ond coil portion 112 connected to the
firs~ coil portion 111 and the first coil 106 and
parallel to hut extendiny in the opposite direction to
the first coil 106.
The gauge 34 also includes indicator
means in the form of a pointer 114 connected in
parallel to the magnet 102 to indicate the amount of
pivotal movement of the magnet 102. The trim gauge 34
also includes a lead 118 electrically connected between
the first coil 106 and the second coil 110 and adapted
to be connected to the variable resistor 46 in the trim
sending device 38. More particularly, the lead 118 i5
~2~t7~2
-12- 67363-709
connected to the terminal 122 of the trim sending
device 38. The variable resistor 46 and fixed resistor
62 in the trim sending device 38 are connected to
groundg
The face 128 of the trim gauge 34 is also
illustrated in Fig. 5. The face 128 includes four
trimming segments separated by lines numbered one
through three, and a tilt segment separated by a fourth
line. After the pointer 114 sweeps through the
trimming segments, thereby indicating ~he general or
approximate angular position of the propulsion unit 18,
the pointer 114 travels across the tilt segment,
thereby indicating the propulsion unit 18 is now in the
tilt range.
In operation, current passing through the
~irst coil 106 and the second coil 110 produces a
magnetic field~ Because the first coil 106 and second
coil 110 are magnetically adjacent and ex~end; in
opposite directions relative to èach another, the
amount of current passing through one coil as opposed
to the other will determine the magnitude and direction
o~ the net magnetic field. The direction of the
magnetic field determines the amount of pivotal
movement of the magnet 102 because the permanent magnet
102 will always be aligned with the direction of the
net magnetic field. As the propulsion unit 18 swings
through the trim range, the resistance of the trim
sending device 38 changes7 thereby changing the amount
of current passing through the coil. This results in a
change in the direction of the magnetic field around
the magnet 102 and produces a torque applied to the
magnet 102. The torque applied to the magnet 102
results in the pivoting of the magnet 102 and movement
~.2~7~
-13- 67363-709
of the pointer 114 as the magnet 102 and pointer 114
align themselves with the direction of the net magnetic
field.
The trim gauge 34 also includes means for
varying the current sensitivity of the gauge, i.e., the
sensitivity of the gauge 34 to the resistance of the
trim sending device 38, in the form of a variable
resistor 126 in parallel electrical connection with one
of the first coil 106 and the second coil 110. More
particularly, the variable resistor 126 is in parallel
electrical connection with the second coil 110.
Alternately, a variable resistor 127 can be connected
in parallel electrical connection with the trim sending
device 38, as shown by dashed lines in Fig. 5. A
calibration resistor in the form of a fixed resistor
(not shown) can also be connected in parallel
electrical connection with the first coil 106, if
desired.
Adjustment of the variable resistor 126
results in a change in the relative amounts o current
passing through the second coil 110, thereby affecting
the resulting position of the pointer 114 produced by
the resistance of the trim sending device 38. The
effect of the variable resistor 126 on the position of
the pointer 114 is greater at greater trim sending
device resistances.
Trim gauges, such as gauge 34, can be
used for various propulsion unit mountiny arrangements
on various marine vehicles. As a result, the angular
position of the particular propulsion unit when the
propulsion unit leaves the trim range and enters the
tilt range will vary between different installationsO
The provision of the variable resistor 126 allows a
boa~ operator to adjust the ~ensitivity of the gauge 34
to the
7~
-14-
particular boat installation so the trim sending
device 38 and trim guage 34 properly indicate the
transistion between the trim range and the tilt range.
In an alternate embodiment, as
illustrated by dotted lines in Fig. 5, a varia~le
resistor 130 could alternat1vely be connected in
parallel electrical connection witn the first coil
106. The varia~le resistor 130 in this case,
however, increases the amount of current sent to the
trim sending device 38 and risks overloading the
device's power rating. Connection of the variable
resistor 126 in parallel with tne second co11 110 i~,
therefore, the preferred embodiment for it sends the
current to ground.
- As illustrated in Fig. G, the trim
gauge 34 also includes means in the form of a knob
134 for adjusting the resistance of the varia~le
resistor 126. The knob 134 is accessible from
outside of the housing 98 so that an operator can
easily change the resistance to calibrate the trim
gauge 34.
Various of the features of the
invention are set fortn in the following claims~
