Note: Descriptions are shown in the official language in which they were submitted.
CA 02437621 2003-08-28
This application is a divisional application of co-pending application
2,278,628, filed February 6, 1998.
SATELLITE DlSFi ANTENNA STAEiLiZER PLATFORM
13AGKGROUN~ OF TIE INOf~NT_ION
1. Fielc! of tt~e Invention. The presE~nt invention relates to a
stabilizer platform for a moving object such as a vehicle or a vessel
and, more particularly, to a stabilizer platform carrying a satellite dish
antenna wherein the antenna is continuously pointed at a target
satellite by controlling only the azimuth and eievatian of the antenna
to compensate for movement of the vessel.
2. Statement ~f the Prob Vim. The popularity of programming
received from a satellite has significantly increased over the past
decade. Today, digitak programming is being delivered by a number
of different companies using satellites to transmit signals to earth-
based small satellite dishes such as dishes 18 inches in diameter. !n
most instances, the consumers install the srnall satellite dish antennas
~ b at a fixed geographic site such as at their Name. Some consumers
install small satellite dish antennas on top of their vehicles such as a
recreational vehicle. When they park the vehicle, they tune in the
desired satellite.
A need exists to permit vehicles that are moving such as
recreational vehicles {RVs), marine vessels and floating sea platforms
to continuously lock into a target satellite even though the vehicle or
CA 02437621 2003-08-28
_2_
vessel moves in different directions. This is accomplished by
mounting a stabilizer platform providing rapid alignment between the
satellite dish antenna targeted on the satellite and the moving vehicle.
Vessels pose a particular problem especially in a heavy sea.
When a vessel moves in water, the direction may change (yaw), the
vessel may tilt along the length (pitch), or the vessel may tilt from side
to side (roll}. Hence the stabilizer platform must rapidly compensate
for changes in yaw, pitch and roll to maintain the small satellite dish
antenna targeted on the satellite. in addition, the stabilizer platform
~ g must be capable of rapid alignment so as to maintain the integrity of
the received signal from the targeted satellite.
Prior art stabilizerplatforms of many types. One
are
mechanicallysimple is the two mount termed the
type axis AZ-EL
mount whichcontrols dish antennain the azimuth (AZ)
the and
elevation (EL) directions. Such AZ-EL mounts typically use a
turntable that may be rotated about the azimuth axis and a support
that can be elevated about an elevation axis. AZ-EL mounts can be
quickly and accurately pointed to any target in the sky. By rapidly
moving the turntable about the azimuth axis and in the elevation axis,
2g these stabilizer systems can compensate for yaw, pitch and roll of the
vessel.
A problem with AZ-EL stabilizer platforms occurs when the
cables that connect to the dish antenna and- to the azimuth and
elevation motors wrap around components of the system during use.
A need exists to have a design that eliminates this wrap problem.
A need exists for an AZ-EL stabilizer platform that has the
azimuth and elevation motors mounted to the base of the stabilizer
platform so as to eliminate the wrapping problem for the electrical
cables.
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When the control motors are placed on the moving part of the
stabilizer platform, not only does it add to the weight of the moving
part but often additional weight must be added to counterbalance to
weight of the motors. A need exists to eliminate the added weight
from the motors on the moving part and the added weight from
counterbalancing.
In certain prior AZ-EL platforms, the AZ and EL driver must be
activated separately. A need exists for an AZ-EL drive system
wherein both drives can be activated simultaneously.
1 G Finally, it is a goo! of the present invention to provide
singularity of control for the AZ and EL axes so that, for example, the
stabilizer platform can be rotated through 360° turns in the same
direction without wrapping of the cables.
,~ patentability search was directed toward the features of the
present invention and this search resulted i:n the following patents.
The "Two Access mount Pointing Apparatus°' (published
October 13, 1994, as International Publication No. WO 94123469)
patent application discloses a pointing arm carrying a satellite dish
antenna mounted to a universal joint supported by a base on a ship.
The pointing arm is rotatabiy mounted within the universal joint for
rotation about first and second control axes. The universal joint
provides rotation of the. point arm through greater than 180 degrees
but less than 360 degrees about each of 'the first and second control
axis while suffering no singularities of control.
2.5 iJ.S. Patent No. 3,599,495 relates to 'a stabilizing platform
using a three axis gimbai system including a gyroscopically stabilized
platform.
1~.S. Patent B~o. 3,999,184 provides a platform having
ePevation, azimuth, roll and pitch motors. The cable control fines for
CA 02437621 2003-08-28
_4'
the rotors are designed with slack to provide elevation trove! of at
least 9C~ degrees and azimuth travel of at least 270 degrees.
l~.S. Patent No. 4,197,548 sets forth an antenna stabilizing
system using three linear hydraulic actuators for pitch, yaw and roll
connected on the mount. Independent elevational positioning of the
antenna is provided.
U.S. ~'atent No. 4.,580,050 sets forth an automatic tracking
system for an antenna using an electronic control connected to roil
and pitch sensors for controlling the AZ and EL drives. The antenna
a9so uses a tracking system for locking onto a satellite. The A~ and
EL drives are alternatively driven.
U.5. Patent No. 4,821,04 discloses a mechanical analog of
the geosynchronous satellite arc and then forces the axis of the
antenna to rotate through the geosynchronous arc.
U.S. Patent No. 5,223,85 sets forth an AZ-EL system for
controlling azimuth and elevation of an array antenna. The array
antenna is pivotally supported on an azimuth axis frame by an
elevation axis. The elevation axis motor is mounted on the azimuth
axis Pram. U.v. i'atent No. 5,227,806 is related to the aforesaid
latent.
U.~. Patent No. 3,355,954 teaches the use of three
gyroscopes and motors mounted to rotating gimbals to obtain a
stabilized platform.
None of the prior art approaches set forth the mounting of the
elevation and azimuth motors on the non-moving support base of the
stabiiizer platform or deliver the signal cable through the center of the
plattors~a so as to eliminate cable wrap.
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3. Solution to the Problem. The present invention provides a
stabilizer platform for a satellite dish antenna that eliminates wrapping
of the motor control and power lines. This is achieved without use of
expensive slip rings or rotary points. The present invention places the
elevatso!~ and azimuth motors on the base of the stabilizer platform
which is fixed to the surface of the vessel or vf:hicle. The placement
of the motors on the base eliminates motor wrap with respect to the
control and power cables attached to each motor. The signal cable
from the satellite dish antenna is passed through the center of the
~ g stabilizer platform. The placement of the motors on the base also
eliminates the requirement for use of countennreights on the moving
parts of the stabilizer platform. both the azirrmth and the elevation
control rnotors can operate on the satellite dish ;simultaneously.
CA 02437621 2003-08-28
_6_
SlDIV111~ARY OF THE INVENTION
A stabilizer platform mounted to a vessel for positioning a satellite dish
antenna. The stabilizer platform of the present invention moves the satellite
dish antenna only in the azimuth and elevation directions. A cylindrically
shaped housing is provided that is maunted to the veasel. The housing has
a formed hollow interior. An azimuth motor and an elE:vation motor are each
mounted in the formed hollow interior of the housing. Azimuth motor control
cables and elevation mater control cables are connE>cted to the motors to
carry signals and power far controlling the operation of the motors. ~n top
of the housing is mounted a platform which rotates with respect to the
housing which is fixed to the vessel. The platform rotates in the azimuth
direction. The azimuth motor is coupled to the platform through a gear
arrangement and rotates the platform about the housing in the azimuth
direction. ~n top of the platform is mounted an elevation drive. The
elevation drive holds the satellite dish antenna. Mounted in the platform is
an elevation gear cluster which rotates with respect to the platform. The
elevation gear cluster is coupled to the elevation drive:. The elevation motor
is mechanically coupled to the elevation gear clusteir so that the elevation
motor can move the satellite dish antenna in the elevation direction. The
azimuth motor rotates the platform in the azimuth direction independently of
the elevation motor moving the satellite dish antenna in the elevation
direction. Hence, the satellite dish antenna can be rapidly positioned in both
the azimuth and elevation directions without the elevation motor control
cables ar the azimuth control cables becoming entangled or moving.
CA 02437621 2003-08-28
t3FttEF ~ESCRtETtOtd OF THfe dR,AWING
Figure 1 sets forth a cut-away perspective of the major
components of the stabilizer platform of the present invention.
Figure 2 sets forth an exploded view of the stabilizer platform of
Figure 1.
Figure 8 sets forth an exploded view showing the
interconnection of the elevation and azimuth motor support.
Figure 4 shows a top planer view of tree motor support of Figure
3.
1g Figure 5 is a cross-section of the rr~otor support of Figure 4
takers along lines 5-5.
Figure 6 is bottom planar view of the rnofor support of Figure 3.
Figures 7a and 7b are an exploded view of the components of
the platform assembly of the present invention.
Figure 8 is a bottom planar view of this platform of the present
invention.
Figure g is a cross-section of the platform of Figure 8 taken
along lines 9-9.
Figure 10 is a top planar view of the platforrn of Figure 8.
Figure 11 is a perspective of the atabiiizer platform of the
present invention.
Figure 12 is a cut-away perspective view of the elevation drive
of the present invention.
Figure 13 is a perspective view c~f the initialization photo
sensors of the present invention.
CA 02437621 2003-08-28
~~~~IIL~~ ~E~~~IhTj~~ ~~ ~H~~'~~I°~~I~~
weroeiew ~ !n Figures 1 and 11, the major components of the
stabilizer platform system 10 of the present invention are disclased for
positioning a satellite dish antenna 80. The stabilizer system 10 is
rr~ous~ted to a vessel 20. The stabilizer system 10 has a base plate 12
which is secured by means of connectors 14 or the like to the vessel
20. !t is to be expressly understood that thE= vessel 20 could be a
surface on a vehicle or other moving object to which it is desired to
affix the stabilizer platform system 10 of the present invention. The
term "vessel" is used for convenience throughout the specification but
is to be broadly interpreted to mean a moving object such as a
recreational vehicle, a truck, a train, a boat, ;a ship, or the like. The
stabilizer platform system 10 of the present invention continually
positions the satellite dish to a target satellite while the vessel moves.
The stabilizer platform 10 has mounted to the base plate 12 a
tubular housing 30. On top of the tubular housing 30 is a platform 40.
Ors top of the platform 40 is mounted a worm gear drive 50. Through
the worm gear drive 50 is disposed a shaft 60 which extends
outwardly in ends 62 on opposing sides of the worm gear drive 50.
On these outwardly extending and opposing ends 82 of shaft fi0 is
fixed a cap 64 and an L-mount 66. The cap dri4 is firmly connected to
the L-mount 66 by means of suitable connectors 68. The
engagement of the cap 64 to the L-mount 6f> and to the shaft 60 is
such that the L-mount 66 and cap 64 rotates with the rotation of shaft
80. The L-mount 66, in turn, is connected to a bracket 70 which is
mounted to the rear of the satellite dish 80 by suitable connectors 72.
The feed support arm 90 is mounted through the interior of the
bracket 70. The end 92 of the feed support arm 90 carries a
cor~vent'sonal feed, not shown.
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The design of cap 64, L-mount 66, bracket 70 and feed support
arm 00, as well as the dish 80, is immaterial to the teachings of the
present invention. The present invention relates to a hove! stabilizer
platform 10 to which any suitable satellite dish antenna 80 could be
mounted to the outwardly extending ends 62 of shaft 60. Indeed, any
suitable device or object (such as dish 80) that needs to be pointed in
a desired direction could be mounted to ends 62. Likewise, the shape
and configuration of the base piste 12, the tubular housing 30, or the
platforrt~ 4.0 are not critical to the teachings of the present invention
although a circular shape for the platform 40 and the tubular housing
30 is most suitable to the implementation of the stabilizer platform 10
as will be further explained. The base plate 12 can be connected to
the tubular housing 30 in any suitable fashion such as by means of
bolts affixing through plate 20 to the battorr~ of the tube housing 30
10 (not shown) or by welding or any other suitable connector.
With reference to Figures 1 and 11, the stabilizer platform 10 of
the present invention is mounted to a moving object 20 for positioning
a satellite dish antenna 80 in the azimuth 140 and elevation 160
directions. The stabilizer platform 10 of the present invention includes
an azimuth mofor 300 which is mounted to the housing 30 and which
in turn is mounted to the vessel 20. In essence, the azimuth motor
300 is mounted to the moving abject 20. Likewise, the elevation
motor 310 is also mounted to the moving object 20. In the preferred
embodiment, these motets 300 and 310 are mounted to the interior
32 of the cylindrically shaped housing 30. It is to be expressly
understood that they could be mounted directly to the vessel 20 and
exposed to the environment. Azimuth control cables 30'1 carry
conventional signals and power for controlling the operation of the
azimuth motor 300 to rotate 14.0 the platfarrn 40. The elevation motor
control cables 311 are connected to the elevation motor 310 and also
CA 02437621 2003-08-28
w
carry conventbonai signgls and power for controlling th~ 0peratlon of
the cl~vatlon motor 310. The stabilizer platform 10 provides a
platfiorrn ~a on top of the cylindrical houslnp 30 for rotating 140 in th~
e~imuth direction, 1'he azir~tuth motor 300 is meehanicelly c~upied
b tl°~uh a gear arrangarnent to the ptatforrn ~0 f~r rotating the
pia~'orrr~ 40 in the azimuth dir~ction 1~~. An elevation ~~ar drive la
rotational9y rn~unted In the piatforrn 40 and 1s trmachanicaily coupled to
the satellite dish ~ntenna 80 to more it in the alavatlan direction i~0.
This e3evatior~ gear drive is c0mprlsed of two components. 'They first is
~ 0 the ~I~vation womn gear driv~ 60 which i~ rrrr~t~nted are top of the
platform 40 and is direc~tiy connected t~ the dish antenna ~0 as
shown. ~'he s~cond la an rslevation gear cluster which 1s rotationally
rte~unted in the platform 4~. The elevativWmotc~r 310 is coupl~d t~
the elevation gear driv~ to raise as~d lower the sakallit~ dish antenna
1~ ~~ in the elevation dir~sction 1~0. The azimuth motor 3D0 rot~Ptas the
platf~rrn in the ~zirrt~tth direction ~ 40 independently gf the elevation
rr~~ter X10 moving the satellite dish antenna ~0 in the eiwatien
dlraio!°~ ~ ~0 s~ tftat the satellite dish antenna ~0 Ben be rapidly
~~~itB~rl~d in ~7t~t~"1 th8 ~l2irrlUtl'1 ~rt~ ~hvati0n direotion$ 140, t g0
~0 vdithout the elevation mot~r control Babies :611 or' the azimuth rnotar
c~ntrol cables 3~1 rttoving.
~tab~lyf~r P_la~tfot°rr~ Ills- In Fi~ures 9 and 2, of the
assembly of the worrn g~~r drive 50 to the platForrn 40 dnd the
assembly oø the platform 40 t~ the tubular housing 30 is shown,
2~ The tubular housing 30 Pa machin~d from a suitable metal such
as an aiurninurr~ alloy. Tubular ~rouePng ~0 has a tormad interior
r~gi~n ~2 within interi~r side walls 34 and a plurality (such as four' of
formed cylindrical passageways 36 sash of which terminakes in a
cylindrical passageway 3~ of .reduced dlarrheter as shown in Figure 1.
A shouldsr 3a c~nnects the fievc passageways 36 and ~6.
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-11-
A motor support 100 is disposed between the platform 40 and
the tubular housing 30. As shown in Figure 1, a bolt 102 is inserted
into passageway 36 to abut against shoulder 39 and engage a formed
hole 104 in the motor support 100. A gasket 110 is placed between
the motor support 100 and the tubular housing 30 to provide a
weather tight seal. In the preferred embodiment, the four
passageways 36 are formed at even spacings around the tubular
housing 30 and four bolts 102 are used to engage the four threaded
holes 104. This firmly mounts the motor support 100 to the upper end
of the tubular housing 30.
The motor support 100, in turn, is assembled to a portion of the
platform 40 to be subsequently discussed. A gasket 120 is provided
as a weather tight seal. The worm gear drive 50 is attached to the
platform 40. A gasket 130 is placed between the worm gear drive 50
and the platform 40 and the housing 50 is affixed by means of bolts
132. It can be observed in Figures 1 and 2 that when the various
components discussed above are connected together the gaskets
110, 120 and 130 provide a weather tight engagement so that the
rerr2ainirag vomponents found within the housing 50, within the
platform 40 and within the tubular housing 30 are protected from the
environment.
3. ~fiotor ~u.,~~ort '100 - In Figures 1, 3, and 4-6 is shown the
general construction of the mounting the motors 300, 310 to the
support 100. Motor 300 is the azimuth rnotor (AZ) and motor 310 is
the elevation motor (FL). These motors are conventional stepper
motors
The motors 300 and 310 are mounted to the bottom 320
(Figure 4) of the motor support 100. Azimuth motor 300 has a shaft
302 and elevation motor 310 has a shaft 312. Around each shaft is a
3Q collar 303 and 313 for motors 300 and 310 respectively. These
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-12-
collars 303 and 313 fit into corresponding formed openings 322 and
324 in the. bottom surtace 320 of support 100. Azimuth motor 300
mounts to support '800 by means of bolts 326. Elevation motor 310
mounts to support 100 by means of bolts 323. When assembled
motors 300 and 310 are firmly attached to support 100 which in turn is
firmly attach to tubular housing 30. Essentially, the motors 300 and
310 are fixedly mounted to the vessel 20. UUhile the preferred
embodiment shows the motors 300 and 310 mounted in the hollow
interior 32 of a tubular housing 30, it is to be understood that any
suitable mount to the vessel 20 could be used including directly
mounting the motors to the vessel without enclosing them in a
housing.
Azimuth gear 330 is connected to shaft 302 on the inside
region 340 of support 100. Elevation gear 350 is connected to shaft
312 of elevation motor 310 also in the interior region 340. The gears
330 and 350 are firmly connected to shafts 302 and 312, respectively
such as by conventional keys, not shown) so that as each shaft
rotates so does the connected gear. l~zimuth gear 330, in the
preferred embodiment, has 16 teeth and elevation gear 350 has 12
teeth. In the preferred embodirpent, the gears are machined from
brass.
As shown in Figure 1, the motors 300 and 310 are mounted
and protected from the external environment in the interior 34 of the
tubular housing 30. Centraiiy located in the motor support 100 is
formed an upstanding collar 360 having a formed hole 362. As will be
explained, the programming signals received by the dish 80 are
delivered through hale 362 and into cable i:31. The control cables 301
and 311 for s~otors 300 and 310 are delivered from the interior 34 of
hosing 30 through weatherproof seal 31 to the exterior of the
housing 30. It is clear from Figure 1, that the motor support 100 is
CA 02437621 2003-08-28
-13.
firmly mounted to the tubular housing 30, carries the motors 300 and
310, and is fixedly attached to the vessel 20. ,As will be explained, the
platform 40 is designed to move in the azimuth direction 140 and the
shaft 60 is to move in the elevation direction 160 without causing the
cables 81, 301 and 311 to twist.
The azimuth motor control cables 301 and the elevation motor
control cables 311 carry the necessary signals and power to control
the operation of the motors 300 and 302. 'such signals and power are
conventional and vary according to the target seeking algorithms
used.
In Figures 4, 5, and 6 the details of thE= motor support 100 are
shown. An annular region 370 is formed below upstanding collar 360.
The annular region 370 has a greater diameter than the diameter of
the formed opening 362. A formed recess 372 exists in the interior
340 of the motor support 100 about formed hole 322 for the azimuth
motor 300. A slot 390 is formed through t~ottom 320 for azimuth
controA and a slot 380 is formed in the bottom 320 for elevation
control. The purpose and functions of these slots 380 and 390 will be
discussed subsequently. In the preferred e~rrrbodiment, these slots
are located at an angle 382 of preferably 30° a,s shown in Figure 6.
4~ ~latf~rrn Assembly '100 - in Figures 7a and 7b the details of
the platform assembly, 700 are shown. The lalatform 40 contains an
elevation gear 710 (Figure 7a) and an azimuth gear 720 (Figure 7b).
The azimuth gear 720, in the preferred embodiment, has 96 teeth 721
and, as shown in Figure 1, the azimuth gear 7°20 is driven by azimuth
drive gear 330 in the direction 332. In the preferred embodiment, the
azimuth drive gear 330 has 16 teeth so that the ratio between gear
720 and gear 330 is 6 to 1. The azimuth gear 720, as shown in
Figure 7b, has the gear teeth 721 located on an inside circumference.
CA 02437621 2003-08-28
14_ :
The elevation gear 710, in the preferred embodiment, has 72 teeth 711 and
is driven in the direction 352 by elevation drive gear 350 which has 12 teeth.
The ratio between gear 710 and 350 is 6 to 1 which precisely equals the
aforesaid azimuth gear ratio. The elevation gear 710, as shown in Figure
7a, has the gear teeth 711 located on an inside circumference.
As shown in Figure 7b, the azimuth gear 720 is connected through
a circular metal plate 730 to the platform 40. Bolts 722 connect through
holes 724 in gear 720 and through holes 726 in plate 730 to hole 832
(Figure 8) in the platform 40 shown in line 723. Opposing location pins 834
locate the gear 720 on the platform 40 and bolts 722 flirmly connect the gear
to the platform 40. As gear 720 rotates in direction 732, the platform 40
rotates in direction 140. The bearing 740 has an outer portion 742 and an
inner portion 744 separated by a bearing race 746. The outer portion 742
freely rotates about the inner circumference 744 about bearings 746. ~fhe
bearing 740 is of conventional design. The azimuth c,~ear 720, by means of
connectors 722, is firmly held in an abutting relationship against the plate
730 which in turn is firmly held against and in an abutting relationship with
the inner portion 744 of the bearing 740. This is shown in Figure 1. The
outer portion 742 is held firmly to the motor support 100 and does not move
as it is fixed in relationship to the vessel. As the azimuth gear 720 rotates
in the direction 732 inner portion 744 of the bearing 740 rotates in the
direction 734.
The details of the platform 40 are shown in Figures 8, 9 and 10.
Platform 40 has sides 800, an upper surface 810 and a formed annular
region 820. An inner ring 830 is formed with a plurality of formed holes 832.
As shown in Figures 1 and 7, pins 834 and bolts 722 are used to engage the
azimuth gear 720 through the plate 730 to inner ring 830. Hence, and as
shown in Figure 1, as azirr~uth drive gear 330 rotates in the direction of
332,
the platform 40 rotates in the direction of 140. This provides the azirr~uth
movement to the antenna 80.
CA 02437621 2003-08-28
=15-
In Figure 7b, a circular retainer 750 and a circular weathershield 760
are shown. With reference fio Figure 1, the retainer 750 is affixed fio the
support 100 by bolts 105 as shown in Figure 2. The outer portion 742 of
bearing 740 engages the retainer 750 as shown. Weathershield 760 is
provided between the retainer 750 and surface 822 of the platform 40 as
shown in Figure 1. The weathershield 760 prevents contaminants from the
environment outside the stabilizer system of the present invention from
entering to the interior 32 of the tubular housing 30. Hence, as the azimuth
motor 300 causes azimuth drive gear 330 to rotate 332 a corresponding
rotation is delivered to the platform 40 as witnessed by arrows 140 and the
rotation occurs about the tubular housing 30 which is stationary. Ring 750,
weathershieid 760 and outer portion 742 of bearing 740 also remain
stationary. The inner portion 744 of bearing 740 rotates with the rotation of
the platform 40.
As shown in Figures 8-10, the platform 40 has an inner annular ring
840 around an upstanding post 850, The center post 850 has a formed
opening 860 which passes through the platform 40. The back surface 810
of the platform is flat. The second formed opening 880 is circular in shape
and abuts against the inner ring 830 as shown in Figures 8-10. Holes 882
are formed in a square pattern about the second formed opening 880 as
shown in Figure 10. This permits the worm gear drive 50 to be mounted to
the platform 40. Second formed opening 880 provides a mechanical
passageway, as will be explained subsequently, 'for the elevation drive
linkage. The elevation gear 710; as shown in Figure 1, engages the
elevation drive gear 350. The bearing 780 fits around elevation gear 710 as
shown in Figures 1 and
CA 02437621 2003-08-28
10_
7a with a plate 790 firmly attached over the inner member 784 of
bearing 780 and to elevation gear 710 by means of location pins 792
and bolts 794 engaging holes 796. This firmly connects the elevation
gear 710 to the inner rotating member 784 of the bearing '780. The
outer member 782 can freely rotate about the inner member ?84
about bearings. The outer member 782 of the bearing 780 as shown
in Figure 1 is firmly connected to the platform 44. Plate 730 by means
of bodts 722 clamps the inner portion 744 of bearing 740 and the outer
portion 782 of bearing 780 into position as shown in Figure 1. Hence,
when assembled as shown in Figure 1, the gear 710 can rotate 712
within the platform 40. Hence, elevation drive gear 350 connected to
the elevation motor .310 rotates 352, the gear 710 and plate 790
rotate 712, as shown, independently of the piatForm 40. At the top of
plate 790 about an upstanding collar 796 is affixed a gear 798 which
is connected to the plate 790 by means of locating pins 802 and bolts
804. Hence, the rotation 352 of gear 350 causes gear 798 to rotate
795 which in turn causes gear 798 to rotate around opening 860. !n
the preferred embodiment, gear 798 has 30 teeth.
in summary, the stabilizer platform 10 of the present invention
provides an azimuth motor 300 under control of power and signals on
cable 301 having its shaft 302 connected to gear 330 which directly
engages gear 720 which is coupled to platform 40 to rotate the
platform in the azimuth direction 140. Bearing 740 enables the
platform 40 to be rotationally connected to the housing 30. It is to be
expressly understood that the use of gear's 330 and 720 to provide
the coupling of motor 300 to platform 40 is only the preferred
embodiment and that other ectuivaient gear arrangements could be
used. Further, the use of bearing 740 to provide independent rotation
of platform 40 about housing 30 is also the preferred embodiment and
that other eguivalent bearing structures could be used. The motor 300
CA 02437621 2003-08-28
provides rotational movement in the azimuth direction 140 for platform
40 (and dish 80) without moving either motor 300 or motor 310 and
without entangling or moving cables 301 and 311.
5. ~~tar~Coaxial Ass~,~y - The rotary coaxial assembly 900
is shown in Figures 1, 3 and 7a. The construction of the rotary coaxial
assembly 900 is not material to the teachings of the present invention
and any suitable rotary coaxial or rotary joint could be utilized under
the teachings of the present invention. The rotary coaxial 900 has an
upper coaxial connector 910 which rotates with platform 40, a lower
coaxial connector 920 which is stationary with the motor support 100,
and a rotary joint member 930 which preserves the signal path
between cable 911 and 81. A boot 940 is provided between the lower
coaxial connector 920 and the motor support 100.
dorm Gear Drive - As shown in Figure 2, the worm gear drive
in mounting over a sealing gasket 130 to the upper surface 810 of the
platform 40. Bolts 132 pass through holes 882 in the platform 40,
through holes 135 in the gasket 130 and into corresponding holes, not
shown, in the housing 50. This firmly seals the worm gear drive 50 to
platform 40. The details of the housing 50 for the worm gear drive of
the present invention is not material. What is important and as
illustrated in Figure 2, is to provide a downwardiy extending gear 54
through a formed opening 134 in gasket 130 and through hole 880 in
platform 40. What is also important is that the housing 50 provides an
oc~twardly extending shaft 60 on opposing sides of the gear drive 50 in
order for the L-mount 66 and cap 64 to connect the dish 80. The
shaft 80 is capable of rotating in directions 1 EaO. This is better shown
in Figcre 1 where gear 54 is shown extending into the region 840
beneath the 'top 810 of platform 40.
CA 02437621 2003-08-28
,..1 g-
Figure 12 shows the details of the engagement with the worm gear
drive in greater detail. The worm gear drive has worm 1200 and worm gear
1210. Worm 1200 is oriented perpendicular to the platform 40 and has a
shaft 1202 which is connected to gear 54. Gear 54 is conveniently attached
to shaft 1202. The number of teeth in gear 54 are identical to the number
of teeth in gear 798 so that there is preferably a one-to-one gear ratio.
F(owever, gear 54 may have less teeth than gear 798 so that gear 54 is of
smaller diameter. This smaller diameter enables gear 54 to easily be
lowered through formed opening 880 during manufacturing. In reference
back to Figure 7a, it is clear that as the elevation gear 710 rotates in
direction 712, so does gear 798 rotate in direction 795. Such rotation 795
causes corresponding rotation in gear 54 which is connected to shaft 1202
which causes worm 1200 to rotate 1204. Worm 1200 has one end 1206
engaging a bearing 1220 in the top 1222 of the housing 50, Hence, end
'1206 of gear 1200 freely rotates in the bearing end. ~1'he opposite end 1202,
as mentioned, is connected to gear 54. However, a bearing 1208 positions
end 1202 in the bottom 1224 of the housing 50. Rotation 1204 of worm
1200 causes rotation 180 of gear 1210. Gear 1210 engages bearing races
on opposing sides of the housing 50 similar to that shown for bearings 1220
and 1208.
The worm gear arrangement 1200 and 1210 along with gear 54 form
an elevation drive which is mounted on the platform 40. White these two
gears 1200 and 1210 and gear 54 are used to move the dish 80 in the
elevation direction 160 in the preferred embodiment, it is to be expressly
understood that any equivalent gearing arrangement could also be used.
The elevation drive is connected to the dish 80 and is mounted on the
platform 40. The elevation drive and its housing 50 rotates as the platform
40 rotates 140.
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The elevation gear drive of the present invention includes the
elevation drive (i.e., gears 54, 1200, 1210) mounted on the platform
40. The elevation gear drive moves with platform 40 and the
elevation gear cluster does not move with platform 40. The elevation
gear cluster includes gears 798, 710, and 3~i0. The elevation gear
cluster is rotationally mounted by means of bearing 780 in the
platform 40. Bearing 780 permits the dish 80 to be driven
independently of the azimuth movement of the platform in the
elevation direction. it is to be expressly understood that elevation
gear cluster design using gears 798, 710 and 350 is only the
preferred embodiment and that other equivalent arrangements could
be used. Further, the use of bearing 780 to provide independent
rotation within platform 40 is also the preferred embodiment and that
other equivalent bearing structures could be used. The motor 310
provides movement of the dish 80 in the elevation direction 160
without moving either motor 300 or motor 310 and without entangling
or moving cables 301 and 311.
Z. ~~erat,~on - The operation of the stabilizer platform of the
present invention will now be explained. First, the movement of the
platform 40 in the azimuth direction 140 wil( be discussed. Next, the
movement of the dish in the elevation direction 160 will be presented.
Finallyr the simultaneous movement in the azimuth direction 140 as
well as in the elevation direction 160 will be presented.
Vllith reference to Figure 1, the azimuth motor 300 when
suitably activated through control signals through cable 301 rotates
332 azimuth drive gear 330. This rotation causes azimuth gear 720 to
rotate which imrrfiedlately causes platform 40 to rotate 140.
Essentially, platform 40 is integral with gear T20. Bearing 740 permits
the platform 40 to rotate freely. Hence, if azimuth motor 300, for
example, is a stepper motor, suitable stepping commands can be
CA 02437621 2003-08-28
m20-
deliverea over control leads 301 to cause the stepper motor 300 to
move the platform in the direction 140.
Assume the elevation of the antenna is to remain at a constant
angle. !n this mode of operations the platform 40 can continually
rotate in multiple 360 degrees turns in the same direction. In this
mode of operation, note that none of the cables 301, 311, 81 become
twisted. indeed, the motors 300 and 310 are firmly fixed in tubular
housing 30 and are stationary. To accomplish the maintenance of the
dish at a constant elevation during such rotation, the elevator motor
would be activated to compensate for the rotation of the platform in
the azirr~uth d!r action. If the elevation motor was not activated, the
dish would raise or lower as the platf~rm rotates in the azimuth
direction. The various ratios contained herein for the elevation and
azimuth gearing is the preferred embodiment. These ratios, of
course, can be appropriately changed to meet other design
reruirements.
The operation of the elevation motor 310 is also under oontrol
of signals in the control leads 311. Again, elevation motor can be a
stepper rraotor . iVlotor 310 rotates 352 elevation drive gear 350, drive
gear 350, in turn, engages elevation gear 710 which causes piste 790
to ,which gear 798 is firmly affixed to rotate 795. Gear 798 engages
gear 54 and provides a corresponding rotation 1204 in worm gear
1200. The rotation of worm gear 1200 causes worm gear 1210 to
rotate which causes the axle 60 to move the dish 80 in the direction
160. fence, individual stepper control signals on control leads 311 to
stepper motor 310 cause the dish 80 to be precisely positioned 160 in
the elevation direoti~n.
Assurrse that the azimuth motor 300 is not activated. The
azimuth motor can be assumed in this scenario to have positioned the
piatforrra ~0 at any desired angular position 140. !f only the elevation
CA 02437621 2003-08-28
motor 310 is activated, the dish 80 can be moved in the elevation
direction 160 through an approximately 90° orientation up and down.
This operation is fully independent of the activation of the azimuth
rotor 300. Bearing 780 enables the elevation gear 710 to freely
rove with respect to the platform ~0.
What has been described above for the azimuth operation and
for the elevation operation is singularity of control. !n both operations,
the cables 301, 311 and 81 do not twist or become entwined.
Because separate control signals are delivered on leads 301
and 311 to motors 300 and 310 effectively, it is to be expressly
understood that under the teachings of the present invention, the
piatforrn 40 and the shaft 60 can be simultaneously operated to move
the dish antennae simultaneously in the azirnuth direction 140 and in
the elevation direction 160. This provides a rapid orientation of the
16 satellite dish to the target satellite.
8. initialization ~ The singularity of control discussed in the
prior section, stabilizer system of present invention must have
initialization.
in Figure 13, the motor support 100 is shown with the azimuth
slot 390 and the elevation slot 380. In each slot is placed a
photosensor. In slot 390 is disposed phatosensor 1300 and in slot
380 is disposed sensor 1310. in photosensor 1300 is a formed gap
1302 and in photosensor 1310 is a formed gap 1312. A beam of light
1304. and 1314, respectively, for sensors 1300 and 1310 is generated
26 from a suitable tight source to a suitable light 'detector, not shown.
This technology is conventional and well known. A pin 1320 (see also
figure 7b) is mounted to the azimuth gear 720. Hence, upon
~nitia.9lZateOra of the stabilizer system of the present invention, the
elevation motor 300 is activated anti( pin 1;320 breaks the light beam
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-22~
130 in sensor 1300. The motor 300 is then stopped. The sensor
1300 is connected to the support 100 which is stationary and contra!
lead 1306 (see Fig. 3) deliver this event outwardly from the housing.
This precisely references the mechanics! orientation of the platform
40 to the electronics of the system and provides a known starting
paint.
Likewise, a pin 1330 is provided into the plate 790 (see also
Figure ~a which is affixed to elevation gear 710). The elevation motor
310 i~ activated dntil pin 1330 breaks the light beam 1314. and sends
a signal on read 1316 (see Fig. 3). The motor 310 is then stopped. !n
operation, first pin 1320 is aligned by the azimuth motor 300 and upon
precise alignment, the elevation motor is activated until pin 1330 is
detected.
In this fashion, the stabi!lzer platform of the present invention is
initialized.
T he invention has bean described with reference to the
preferred embodiment. fVlodifications and alterations will occur to
others upon a reading and understanding of this specification. This
specification is intended to include all such modifications and
alterations insofar as they come within the scope of the appended
claic~s or the equivalents thereof.
