US 3202015 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
ug- 1955 G. E. MOUL, JR. ETAL 3,202,015
RADAR ANTENNA POSITIONING DEVICE Filed Sept. 10, 1963 2 Sheets-Sheet 1 GEORGE E. MOUL,Jr. ROBERT W. FOWLER INVENTORS ATTORNEY 24, 1965 G. E. MOUL, JR., ETAL 3,202,015
RADAR ANTENNA POSITIONING DEVICE Filed Sept. 10, 1963 2 Sheets-Sheet 2 GEORGE E. MOUL,Jr.
ROBERT W. FOWLER INVENTORS BY WWW ATTORNEY United States Patent 3,202m RADAR ANTENNA PosrTIoNuso nnvrcn George E. Moul, Jr., Silver Spring, and Robert W. Fowler,
This invention relates generally to radar antenna positioning devices, and more particularly to an improved antenna mount wherein movement of an antenna element is obtained by the use of two pivoted, arcuate drive members.
Radar antennas of the type utilized for search purposes in aircraft and missiles require a mounting capable of providing extremely flexible movement of the antenna element. Various schemes have been proposed for mounting antennas, but all have been deficient in one or more respects. The most common faults of antenna mounts are a lack of non-rigid support of the antenna element, severe backlash in the drive mechanism, and unevenness of movement. The antenna support of the present invention to a great extent solves these problems.
It is an object of this invention to provide an antenna mount so constructed as to provide rigid support for the antenna over a wide range of movements.
Another object of the invention is to provide a support for a movable antenna so constructed as to be smooth in operation and substantially free of backlash.
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 is a side elevation, partly in section, of the invention, with the antenna element in a depressed position;
, FIG. 2 is a front elevation of the antenna mount, with the antenna element removed;
FIG. 3 is a rear elevation of the antenna mount, showing the gyros employed but with the arcuate drive members removed; and
FIG. 4 is a horizontal section, partly in elevation, with the antenna element facing obliquely toward one side.
The antenna mount of the present invention includes an antenna element having a pair of mutually perpendicular, arcuate drive members pivotally attached thereto. The antenna is pivotally mounted on a support post, and the arcuate drive members are driven by motors mounted on a base to which said support post is attached, the arcuate members having gear teeth on their external surfaces which mesh with worm gears on the output shafts of the drive motors.
Referring now to the drawings, a support base is indicated at 2 in FIG. 1, and comprises a cylindrical rim 4 having a web 6 extending thereacross. The base 2 may conveniently be mounted in the forward end area of an aerial missile (not shown). Mounted on the base is a support element 5, said support element consisting of a central support post 8 and four radial support legs 7, the support legs being secured at their inner ends to the web 6, and outer end portions of companion pairs of said legs securing said post 8 therebetween.
As seen in FIGS. 1 and 4, the outer end portion ll) of the support post 8 is bifurcated, and receives an axle 12 therein which is pivotally secured in position by a pin 14 that extends through said portion 10. The axle 12 provides the principal support for a circular antenna element 16, and is pivotally attached to a pair of aligned bosses 15 mounted on the rear wall of said element near the axis thereof.
3,202,015 Patented Aug. 24, 1Q65 As shown in FIG. 4, the antenna element 16 has a central recess 18 therein, within which is pivotally mounted, by ball bearings 20 and 22, a rotatable disk 24. The disk 24 has a central opening 26 therein for receiving a flanged keeper plate 23, the plate 28 being secured to the antenna element 16 by screws 29. A flange St) on said plate 28 extends over the bearing 22 and serves to clamp the disk 24 between the bearings 24 and 22 to thereby secure said disk to the antenna element.
The disk 24 has a boss 32 and a radially extending plate 34 thereon, the plate 34 terminating near the outer periphery of element 16 in a boss 36. Pivotally attached to the latter boss by a pin 38 is one end of a semi-circular drive member 40, the other end of said drive member having a radial support arm 42 thereon which is pivotally connected with the boss 32 by a pin 44.
Attached to the antenna element 16 near the outer periphery thereof, and in alignment with bosses 15 is a pair of bosses 46 and 43 (FIG. 1). As shown in FIG. 1, a second semi-circular drive member 50, having a greater radius than the drive member 40, is pivotally attached at its ends to said bosses 46 and 4S, and passes through an opening 52 in the support element 5 between the inner end of the post 8 and the web 5. Similarly, as shown in FIG. 4, the drive member 4t) passes through the opening 52 in said support element 5, between the support post 8 and the drive member 5% and at a right angle to said drive member Sii.
As shown in FIG. 1, the drive members 40 and 50 are each formed with tracks 41 between which are located raised teeth 51. Pairs of rollers 56 and 58, mounted on a concentric ring 54 formed on the web 6 and engaging the tracks 41, limit the drive members 49 and St) to armate movement.
The web 6 has an elongated radial opening 60 therein, Withinwhich is mounted, on trunnions 62, mounted in bearings 63 on the web 6, a drive motor 64. An output shaft 66 of the motor 64 has a worm gear 63 secured thereto which meshes with gear teeth 51 on the drive member 50. A housing 67 is attached to the casing of the motor 64 to enclose the output shaft 66 and the worm gear 68. The housing 67 is provided with a cutout 69 to permit the gear teeth 51 to engage the worm gear 68. Similarly, a motor 72 is mounted on trunnions 74 within a radial opening 76 in the web 6, and the output shaft 78 thereof has a worm gear 80 thereon which engages with gear teeth 51 on the external surface of the drive member 49. A housing 81 is attached to the casing of the motor 72 to enclose the output shaft 78 and worm gear 88. The housing 31 is provided with a cutout 83 to permit the gear teeth 51 to engage the worm gear 80.
To eliminate backlash in the shafts of the motors 64 and 72, springs 84 and 86 are confined between the web 6 and the housings 67 and 81 of said shafts, and urge said housings toward the drive members to insure positive engagement of the worm gears 63 and 8%) with said members. To prevent displacement of the spring 84, it bears against a shoulder on the web 6 and is mounted in a socket 87 which is formed in an extension element 87a that is attached to the shaft housing 67. Displacement of the spring 86 is prevented by mounting it in a socket formed in a protrusion 89 on the web 6, the outer end of said spring 86 bearing against the housing 81 near its free end.
Actuation of the motor 64 will cause the drive member 59 to move through the opening 52, thus tilting the antenna element vertically, and actuation of the motor 72 will cause the drive member 40 to move the antenna element hori- Zontally.
As shown in FIG. 3, the antenna element 16 has a gyroscope 88 secured thereto in alignment with the axle 12 ticed otherwise than as specifically described.'
by brackets 90, and a gyroscope 92 securedto the plate 34. The two gyroscopesfurnish information about the 16 is positioned parallel-to the web 6, which is its neutral position. v Actuation of motor 72 will move theldrive member 40 and cause the antenna element to pivot about" the axle 12 and thealigned bosses 46 and' 48. Similarly, actuation of the motor 64 will move the drivemember 5i) and will cause the element 16 to pivot about the pins 14, i
38, and 44.
When'a compound movement, i,e., one about both pivotal axes, .is desired, motors 64 and 72 are both actu-' ated. As both drive members 40 and'50'move simultaneously, the disk 24 will partially revolve to permit the anten- 'n'a element 16 to, move without binding} Thus, the antenna element can be positionedto point in any desired direc tion, subject to limitations imposed by the radii of the drive members 40 and 50 and the structure upon which'they are mounted. l
The use of the geared drive members provides animportant advantagein positioning the, antenna element, in that it makes possible the use of very large gear ratios between the drive members and the motor shaft. For example, a ratio of 344m 1 is easily obtainable. The precise positioning of the antenna element made possibleby such high ratios is obvious, and greatly enhances the accuracy of the antenna.
Obviously, many modifications and variations'of the present invention are possible in the light of the above teachings. vIt is therefore to be understood that within the scope of the appended claims the invention may be prac- What is claimed is: V 1. An antenna mount, comprising (A) a movable antenna means,
(B) first arcuate means connected to said antenna means, (C) second arcuate means connected to said antenna means so as to intersect perpendicularly the plane of said first arcuate means, said first and second arcuate I sired positioning of said antenna means and operably connected to move each of said first and second arcuate means about said mutually perpendicular axes so as to position said antenna means as desired; 2. The device as recited inclaim 1, including, (E) a base member, and
(F) supporting means on, said base member pivotally.
mounting said antenna means. 3. The device as recited in clai 2,-Where1n said first arcuate means is pivotally connected to said antenna means and said second arcuate means is pivotally and rotatably it connected to said antenna means.
4. The device as recited in claim 3, wherein said base member is provided with an opening receiving said first and second arcuatemeans therethrough.
The device as recited in claim 5, means comprises .a-'
wherein said arcuate pair of' substantially semi-circular drive members,- a
j 7. .The device as recited in claim 6, Whereinsaid drive 'm e'ansjcomprises a first and .asecond motor pivotally mounted on said base, said motors havingoutput shafts,
1 and worms on said output shafts and engageable with said semi-circular drive members. 1
'- 8. The device as recited in claim 7, wherein said base member is provided with guide rollers tovlimit lateral shifting of said. semi-circular drivemembers; V
9. The device as recited in claim 7, including 1(l-i) antibacklash springspositioned on said base and urging said wormsinto eugagementwith said semicircular drive members; a i
10. An antenna mount, comprising 1 (A) a base'member including a cylindrical outer rim, an internal traverseweb, and'taperecl intersecting supportle'gs' projecting-from said web and having an opening adjacentsaid web, I (B) a supportjpost mounted'at the intersection of said support legsand located above said opening,
' (C) :a radar antenna element pivotally connected to said support postabout two mutually perpendicular, intersecting axes, said antenna element having va central recess and a rotatable disk element mounted therein, V V
v .(D) a first semi-circular drive member pivotally connected to said antenna element in axial relation with one ofjsaid axes and having gear teeth disposed about its outer periphery, H I t (E) a second semicircular drive member having a radius. smaller than said first drive member and pivotally connected to said'rotatable disk element,
1 inaxial relation with the other of said axes, said first andrsecond drive members passing through 'said leg "openmg, (F) at least one pair of guide rollers for each of said 7 drive members attached to said base forlimiting lateralmotion of said drive members,
' v (G) drive mechanism mounted on said base including first and second drive motors pivotally mounted on said' basefoutputshafts connected 'to said motors,
. shaft housings encasing said output shafts and attachedto saidmotors, worms connected 'to'said out- ,put shafts and engaging said drive member gear I v teeth, and
(H) antibacklash springs positioned on said base and engageablewith saidhousings to urge said worms into engagement with said drivemember gear teeth.
; References Cited the Examiner UNITED STATES PATENTS T 2,348,734 -5/44 Freeman; 74-425 X DON A. WAITE, Primary Examiner.