US2861235A - Servosystem control unit for antenna rotators - Google Patents

Description

1958 J. P. CHADOWSKI ETAL 2,861,235

SERVOSYSTEM CONTROL UNIT FOR ANTENNA ROTATORS 5 Sheets-Sheet 1 Filed June 22, 1954 FIG. I

INVENTORS JOSEPH P CHADOWSK/ B! & ANTHONY 6. TURK A T TORNE Y5 Nov. 18, 1958 J. P. CHADOWSKI ETAL 2,861,235

SERVOSYSTEM CONTROL UNIT FOR ANTENNA ROTATORS Filed June 22, 1954 5 Sheets-Sheet 2 INVENTORS 3 JOSEPH P CHADOWSK/ y 8 ANTHONY G. TURK A TTORNE Y5 1958 J. P. CHADOWSKI ETAL 2,86

SERVOSYSTEM CONTROL UNIT FOR ANTENNA ROTATORS Filed June 22, 1954 3 Sheets-Sheet 3 INVENTORS JOSEPH P CHADOWSK/ 8 ANTHONY G. TURK ULMMW ATTORNEYS United States Patent SERVOSYSTEM CONTRDL UNIT FOR ANTENNA ROTATORS Joseph 'P. Chadowski, Brooklyn, and Anthony G. Turk, Cleveland, Ohio, assignors to Cornell Dubilier Electric Corporation, South Plainfield, N. 3., a corporation of Delaware Application June 22 1954, Serial No. 438,559

'3 Claims. .(Cl. 318-311) I The present invention relates in general to 'a selector control unit for antenna rotators, and more particularly is "mounted on a motor-driven rotator so that the antenna may be rotated by remote control to any desired direction. The control unit employed generally. consists of a switch for closing the motor circuit, and indicating means for showing the position of the antenna. In some control units two switches are used so that a reversal of totation may be obtained. The switch is closed to actuate the r'otator, and it is opened by the operator when the indicator shows that the antenna has reached the desired position of directional orientation or angularity. v

it is a primary object of our invention to provide a control unit of the character described with which a rotator may be actuated to rotate the antenna to a pre-selected position of angularity.

Another object of our invention is to provide a control unit which is automatic in operation, that is, which requires no supervision or manipulation by the operator other than the pre-selection of the position to which the antenna is to be rotated.

A further object of our invention is to provide a control unit provided with energy accumulator means for maintaining said unit in operation in response to initial manipulation thereof.

Still another object of our invention is to provide a control unit having readily accessible means for effecting adjustment or synchronization thereof.

Other objects and advantages of my invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is a front elevation of a control unit embodying the features ofour invention, taken in the direction indicated by line 1-1 of Fig. 2, and portions thereof being broken away to reveal details.

Fig. 2 is a longitudinal cross-sectional view taken on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary sectional view taken on line 33 of Fig. 2 and showing details of the selector assembly.

Fig. 4 is a fragmentary cross-sectional view taken on line 44 of Fig. 2 and showing details of the energy accumulator assembly.

Fig. 5 is a plan view of a portion of a remote servomotor assembly or antenna rotator showing the pulsing switchsassembly.

Fig. 6 is a fragmentary cross-sectional view taken on line 6-6 of Fig. l and showing details of the escapement assembly.

Fig. 7 is a schematic wiring diagram showing the electrical connections between the various components of the control system.

Referring more particularly to Figs. 1-6 of the drawings, We have shown an automatic control unit which is housed or contained in an ornamental casing 10, which may be of molded plastic resin or the like, and which is mounted on rubber supports 11. The elements 11 are secured to the casing 10 by screws 12 which extend through the bottom of the casing 10 and threadedly engage a base plate 13. The screws 12 also serve to secure the casing to the base plate 13.

Mounted on the rear of the chassis or base plate 13 is a conventional terminal strip 14 which, in this instance, is provided with four terminals 15. The terminal strip 1'4 is secured to a bracket 16 which also is traversed by a conventional plug-in type of power cord 17. The bracket is welded to thebase plate 13. Access to the terminals 15 may be had through a suitable aperture 18 which is provided in the casing 11).

Also mounted on the chassis 13 is a step-down transformer 19 and a condenser 20. For clarity of detail, we have not shown the various connecting wires in the views of the parts, these connections being shown in the wiring diagram of Fig. 7 where they will be clearly understood by those skilled in the art.

The remainder of the operating elements of the control unit are best described by considering the principal sub-assemblies individually. These sub-ase'mblies may be functionally defined as follows:

(a) A selector assembly 21,

(b) An energy accumulator assembly 22, (0) An escapement assembly 23, and (d) A pulsing switch assembly 24.

The selector assembly As best seen in Figs. 2 and 3 of the drawings, the selector assembly 21 includes a shaft 25 which is rotatably journalled between spaced front and rear plates 26 and 27 respectively. The front plate 26 is provided with a flange 28 which rests upon base plate 13 and is secured thereto by threaded fasteners 29. The rear plate 27 is secured to the front plate 26 by means of spacer posts 30 and screws 31.

A selector wheel '32, of insulating material, is fixedly secured to shaft 25' for rotation therewith. The periphery of the wheel 32 is provided with a series of circumferentially-spaced detent notches 33 which, in this particular embodiment, are uniformly spaced 6 from each other thus providing a total of 60 such notches in the 360 of circumference.

Secured to wheel 32 on the opposite faces thereof, as by rivets 34, are a pair of commutator discs 35, 36 which are electrically insulated from each other. The disc 35 has electrical connection to one blade 38 of a switch 37,

the other blade 39 of the switch being in electrical contact with the disc 36. Both blades 38, 39 are fixedly secured to the selector wheel 32, however, the switch blade 38 is flexible or resilient so that it can be moved horizontally away from switch blade 39 to effect opening of the switch 37.

That portion of the wheel 32 which is diametrically opposite the switch 37 has fixedly secured thereto, as by rivets 43, a pair of contact arms 40, 41, each of which has a horizontally extending leg 42. Each of the legs 42 lies adjacent an opposed side of a horizontally extending embossment or projection 44 on wheel 32. The projection 44 serves to separate one contact arm from the other, so that the arms 40, 41 are electrically insulated from each other. Another function of the projection 44, is to brace or reinforce the contact legs 42 so that they will not fiex or bend during the operation of the control unit, to be described hereinafter. A portion of the shaft 25 is bored out as at 45 and recessed as at 46 to provide a convenient conduit for lead wire 47 which connects to contact arm 40, and lead wire 48 which connects to contact arm 41. Both lead wires are connected to the terminal strip 14, as shown in Fig. 7. The contact arms 40, 41 are circuit elements of a lowvoltage control circuit, and the switch 37 is an element of a power circuit, as will appear more fully hereinafter.

As best seen in Fig. 1, the selector assembly 21 also includes a pair of Phosphor bronze leaf brushes 49 which are secured in horizontally spaced relationship on an insulating block 50 which is mounted on the rear plate 27 "in a position to cause each of the brushes to have wiping electrical contact with one of the commutator discs 35, 36. The block 50 also supports a resilient arm or leaf spring 51 which carries a detent ball 52 on its free end. The ball 52 is adapted to yieldably engage the notched edge of the selector wheel 32 to restrain its movement. The brushes 49 are connected by suitable leads to the power cord 17, through the primary coil of the transformer 19 as an element of the circuit.

The energy accumulator assembly As best shown in Figs. 2 and 4, the energy accumulator assembly 22 includes a toothed follower gear 53 which is rotatably mounted on shaft 25 in operative engagement with the selector assembly 21. The gear 53 may be maintained against axial displacement by suitable means such as a snap-ring 54 which is secured in an annular recess on shaft 25.

The gear 53 is provided with an axially offset marginal projection 55 in which is threadedly received a co-axially extending camming screw 56. The cam element 56 is adapted to engage and displace the switch blade 38 axially so as to open the switch 37. This displacement will only occur when cam 56 and blade 38 are directly opposite each other or in phase. A hairpin spring 57 serves to prevent vibratory loosening of screw 56 while at the same time permitting adjustment of the screw whenever necessary.

Rotatably mounted on the hub of the gear 53, as on sleeve bearing 58, is an open-faced cylindrical casing or drum 59 containing a spirally-coiled flat spring or torsion spring 60 having the outer end thereof anchored to the drum as at 61 and having the inner end thereof anchored as at 62 to any one of several projections 63 which are provided on a drum cover 64. The cover 64 is also rotatably mounted on the sleeve bearing 58.

The cover 64 is provided with a contact arm 65 and the drum 59 is provided with a similar arm 66. In assembling the device, the cover 64 is rotated relatively to the drum 59 in order to pre-energize the spring 60 and thus establish an initial torque relationship between the cover and drum. The cover 64 would be urged to rotate counterclockwise (Fig. 4) and the drum 59 would be urged to rotate clockwise. However, the gear 53 is provided with a projection 67 which is disposed in the path of movement of the contact arms 65-66 and prevents such relative rotation between the drum and the cover. The projection 67 maintains the arms 65-66 in parallel spaced relationship and defines a space between the arms which is of sufiicient width to accommodate the projection 44 and the opposed legs 4-2 of contact arms 40, 41 of selector wheel 32, while allowing a small clearance space 68 to either side thereof. It will be understood that projection 67 is diametrically opposite the cam screw 56 so that the projections 44 and 67 will assume the positions shown in Fig. 4 when the screw 56 is directly opposite switch blade 38.

Both arms 65 and 66 are electrically grounded, and

one side of the transformer 19 secondary is grounded as shown.

The escapement assembly As shown in Figs. 1 and 6, the escapement assembly 23 includes an escapement wheel 69 which is rotatably mounted on a stub shaft 7 0 which is secured between the front and rear plates 26, 27. Disposed on opposite sides of the wheel 69 and integrated therewith are gears 71 and 72. The gear 71 is in engagement with the follower gear 53 and is actuated thereby. The gear 72 engages a pointer gear 73 which is rotatably secured to shaft 25 adjacent the exterior of front plate 26. The gear 73 carries a finger or pointer 74 which is frictionally secured thereto and which overlies a transparent dial'75 which will be more fully described hereinafter.

The escape wheel 69 is provided with a series of uniformly spaced circumferential notches 76, in this instance there being twelve of such notches. The wheel 69 is normally prevented from rotating by a pawl assembly 77 which is pivotally secured to the front plate 26 by means of a stud or post 78. The assembly 77 includes a rocker arm or lever 79 which is pivotally movable about the axis of post 78, rearwardly of the wheel 69, and is provided with spaced apertures or slots 80 and an extension or finger 81 which projects through the base plate 13 so as to be accessible from the underside of the control unit. Also pivotally mounted on post 78 are a pair of pawls 82, 83 which are adapted to selectively engage the notches 76 and secure or lock the wheel 69 against rotation, thus also preventing rotation of the follower gear 53.

Each of the pawls 82, 83 is provided with a lateral extension 84 which traverses one of the apertures or slots 80 in arm 79. A coil spring 85 is connected across the pawls 82, 83 to urge them toward each other. This arrangement provides a yieldable or resilient lost-motion connection between the pawls and the rocker lever 79. The lever 79 also is yieldably maintained in the position shown in Fig. 1, by means of a coil spring 86 which is anchored to a bracket 87 on the front plate 26.

A link 88 is pivotally secured to the arm 79, as at 89, and the other end thereof is operatively connected to the movable core or plunger 90 of a solenoid 91 which is secured to the rear plate 27 so as to lie intermediate the front and rear plates 26, 27.

In response to energization of the solenoid 91, the

causing the arm 79 to pivot counter-clockwise. This pivotal movement brings the lower pawl 82 into springloaded engagement with the edge or periphery of the escape wheel 69 intermediate two of the notches 76. Further pivotal movement of the arm 79 causes the upper pawl 83 to be disengaged from the notch in wheel 69. The wheel 69 will then rotate in response to the torque impressed upon it by torsion spring 60 through the gear 53. Its direction of rotation will depend upon the direction of rotation of gear 53. The wheel will then rotate until the pawl 82 engages a notch 76 and thus locks the wheel 69 against -further rotation. When the solenoid 91 is deenergized, the spring 86 causes rocker arm 79 to pivot clockwise and pawl 83 will engage the periphery of wheel 69. Further rotation of arm 79 causes disengagement of the lower pawl 82 and the wheel 69 will continue its interrupted rotation until pawl 83 engages a notch 76. During this cycle of movement of the rocker arm assembly 77, the escape wheel has rotated a total of 30, equal to the angularity between adjacent notches 76. By means of the gear ratios established between follower gear 53 and gear 71, and likewise between gear 72 and pointer gear 73, the 30 rotation of escape Wheel 69 corresponds to 6 of rotation of follower gear 53 and pointer gear 73 and selector wheel 32. The 30 rotation of the wheel 69 also corresponds to one pulsation or energization of the 9lenoid 91 in response to 6 rotation of an antenna to overlie the dial 75.

structure by means of a pulsing switch assembly which will now be' desc'ribedr It will be understood that various combinations-of degrees of angular rotation can be utilized, other: than tho'seherein: described.

The pulsing switch assembly As shown in Fig. 5, the pulsing switch assembly 24 includes the parallel normally open contact arms 92 and 93, which areconnected in series with the solenoid 91 (Fig. 7) and whichare supported on a motor mounting plate 94 by a bracket 9'5. A gear 96 is mounted rotatably on the motor plate=94 'soas to mesh with=a gear 97 which forms part of theg'ear train- 98 of a conventional motor-driven antenna rotator 101 having a shaft-mounted drive pinion 101a. Thegear 96' isprovided with. a camming: projection 99 which isadaptedto engage a portion 100 of the resilient switcharm 92 so as to displace the arm 92 and bring it into contact-with arm 93 to close the solenoid circuit. The gear ratios are so designed that gear 96 will rotate 360' in response to 6 of rotation of the antenna structure.

The foregoing describes the major components of the control unit.

The transparent dial 75 is secured to the front plate 26, as by means of screws 102 and is provided with a series of suitable directional indicia marks 103, preferably circumferentially spaced in increments of 6, in this instance.

A molded knob 104 having a transparent flange portion 105 is fixedly secured to the end of shaft 25 so as The knob is provided with a single index mark 106. The pointer 74 extends through .an opening 107 in the dial 75 so as to lie in between the dial and the flange 105 of knob 104.

One or more lights 108 may be secured to the front plate 26 to illuminate the dial 75.

Means are provided for limiting the rotation of knob 104 and selector wheel 32 to a maximum of 360. This is accomplished by a latch element 109 (Fig. 1) which is pivotally secured as at 110 to back plate 27. One arm 111 of the element 109 extends rearwardly into an armate slot 112 provided in plate 27, and the edges 113 of the slot limit the movement of the latch 109. Another arm 114 of the latch 109 extends forwardly of plate 27 into the path of movement of a projection 115 (Fig. 2) which is provided on wheel 32. It will be apparent that latch element 109 will arrest rotation of wheel 32 when ever projection 115 causes arm 111 to abut either edge 113 of slot 112.

The operation of the control unitv By reference to the schematic wiring diagram shown in Fig. 7, the operation of the device may be more readily understood.

When follower gear 53 and selector wheel 32 are in the position shown in Fig. 2, the cam screw 56 maintains the switch arm 38 out of Contact with switch arm 39. The power circuit through the primary winding of transformer 19 is thus open and the rotator does not operate. Under these conditions, the pointer 74 should be in registry with the index mark 106 on knob 104.

When the knob 104 is rotated in either direction, the selector wheel 32 will be rotated in the same direction a like degree. The contact arm 38 will then be out of phase with screw 56 and the switch 37 will be closed causing transformer 19 to be energized. The escapement assembly 23 prevents follower gear 53 from rotating when wheel 32 is rotated. Depending upon the direction in which wheel 32 is rotated, either contact arm 41 will engage contact arm 65 on drum cover 64 and rotate the cover clockwise (Fig. 4), or contact arm 40 will engage contact arm 66 on drum 59 and rotate the drum counterclockwise.

The relative rotation between the drum 59 and cover 64 is translated into energization of torsion spring 60 which, through projection 67, is, impressed as a torque upon gem-53.

Assuming now that contact; arm 41. has engaged contact arm 65, this serves. to. close a low voltage. circuit through the winding 116' of the rotator motor and through a thermal. overload switch 118, which. is. provided; for protection of the circuit. The antenna rotator will. then rotate in: one direction- The electrical connectionsare shown by terminals 15a, 15b, 15c and 15d. on. control unitter minal strip 14 and by terminals a, 120b,", 1200 and'120d' on rotator terminal strip 119..

During each. 6 rotation. of the; rotator; the .cam; gear 96 will rotate through one complete revolution and will momentarily close the switch 92-93 to transmit an electrical impulse to solenoid. 9:1.v The energization of solenoid 91 will actuate the, escapement wheel, 69 in the manner heretoforedescribed. For each: solenoid impulse, the escapement wheel 69 will permit the follower gear 53 to rotate 6.

As soon as the antenna rotator has energized the solenoid a sufiicient number of times, the follower gear 53 will again be in phase with the selector wheel 32 and the cam screw 56 will open switch 37 to interrupt the transformer circuit. The rotation of the antenna rotator will then cease. At this point the pointer 74 will again be in registry with the index mark 106.

If the rotation of knob 104 is in the opposite direction, the contact arm 46 will engage contact arm 66 to establish a motor circuit through reversing winding 117 so that the rotator motor would revolve in the opposite direction. The rotator would then continue its rotation, in the manner above-described, until the follower gear 53 was in phase with selector wheel 32.

When the control unit is installed, it may be tested by rotating knob 104 to one limit of position and noting whether pointer 74 comes into registry with mark 106 during operation of the rotator. If it does not, the lever arm 79 of the escapement assembly may be manually manipulated by means of finger 81 to bring the gear 53 into phase with wheel 32 and thereby bring pointer 74 into proper position. If the pointer registers with index mark 106 in one limit of position of knob 104, the knob should be rotated to its other limit of position to determine whether the pointer properly tracks the index mark. If it does not the lever arm may be manually manipulated as aforesaid to obtain the proper synchronization. As heretofore stated, the pointer 74 is frictionally secured to the pointer gear 73 so that the pointer may be independently adjusted if necessary.

The antenna can be oriented with the directional markings 103 in a manner familiar to those skilled in the art.

It is to be understood that the forms of our invention, herewith shown and described, are to be taken as preferred examples of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of our invention, or the scope of the subjoined claims.

Having thus described our invention, we claim:

1. In a control unit for an electrically-actuated rotator device, the combination of a rotator-actuating circuit including a normally-closed rotator-actuating switch rotatably mounted on said unit, a movable switch-opening member operatively engaging said switch, means for rotat ing said switch in either direction out of engagement with said member to close said switch, a single torsion spring having one end thereof operatively associated with said switch and having the other end thereof operatively associated with said member, said spring being energized in response to rotation of said switch, and means responsive to energization of said spring for moving said switchopening member in a corresponding direction to reengage said switch.

2. In a control unit for an electrically-actuated rotator device, the combination of a rotator-actuating circuit ineluding a normally-closed rotator-actuating switch, a rotatable selector element supporting said switch for orbital movement, a follower member mounted for coaxial rotation relatively to said selector element, a switch-opening projection provided on said member in the path of movement of said switch and normally engaging said switch, a torsion spring carried by said follower member, means on said selector element engageable with either end of said spring to energize the same in response to rotation of said selector element relatively to said follower member, and means on said follower member engaged by the other end of said spring to urge said member to rotate into switch-opening position.

3. A combination as defined in claim 2 wherein said torsion spring is pre-stressed, one end of said spring being secured to a first arm mounted for coaxial rotation relatively to said element and said member, the other end References Cited in the file of this patent UNITED STATES PATENTS 2,090,812 Schmitt Aug. 24, 1937 2,340,174 Chance Jan. 25, 1944 2,436,068 Hegy Feb. 17, 1948 2,578,347 Gagnaire Dec. 11, 1951 2,680,223 Hammett June 1, 1954 2,682,628 Jordan et al June 29, 1954 2,682,629 Jordan et al June 29, 1954

Images