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Title:
Antenna rotator
United States Patent 2498957
Abstract:
The invention relates in general to rotating mechanisms and more particularly to a device for rotating a shaft relative to a housing, such as the shaft of an antenna rotatable relative to a supporting housing. In the utilization of higher frequency electromagnetic waves, such as are at present...


Inventors:
Jordan, Richard H.
Publication Date:
02/28/1950
Assignee:
ALLIANCE MFG COMPANY
Primary Class:
Other Classes:
310/67R, 310/91, 318/490, 318/739, 343/766, 343/874
International Classes:
H01Q3/04
View Patent Images:
Description:

The invention relates in general to rotating mechanisms and more particularly to a device for rotating a shaft relative to a housing, such as the shaft of an antenna rotatable relative to a supporting housing. In the utilization of higher frequency electromagnetic waves, such as are at present being used for frequency modulation and television channels, the problem of quickly and accurately orienting an antenna to better receive a de- 1i sired signal is becoming- more acute. This invention deals with such problem of quickly and accurately orienting an antenna array. By the use of a rotatable and directional receiving antenna array, the maximum signal strength of 1l a desired signal may be obtained by rotation of this antenna in a horizontal plane. Also, where two signals are interfering, the antenna array may be oriented in a direction to receive a minimum signal strength from the interfering signal 21 to thus achieve a maximum of desired signal to interference ratio. A great majority of the receiving antenna arrays available at present for frequency modulation and television reception are of the dipole or folded dipole type with or 24 without reflecting dipoles, and are mounted on or are adapted to be mounted on a vertical cylindrical shaft, such as standard electrical thin wall conduit. A specific object of this invention is to provide a weatherproof rotator mechanism 3( which may carry and rotate an antenna array and which may be remotely controlled by a remote control box placed near the radio or television receiver.

An object of the invention is to provide relative rotation movements between two shafts.

A further object of the invention is to provide a device for rotating an antenna such as a radio or television antenna.

A further object of the invention is to pro- 410 vide an electrically powered device for rotating an antenna which will be waterproof, light and strong.

Another object of the invention is to provide a device for rotating an antenna having a shaft -15 wherein the shaft is receivable within a hollow shaft of the rotator and such hollow shaft has spaced bearing and clamping means to clamp to the antenna shaft.

A further object of the invention is to pro- 5o vide an antenna rotating mechanism which has an electric motor for providing rotation of the antenna and which may be remotely controlled.

Another object of the invention is to provide an antenna rotating mechanism which will rotate an antenna substantially 360 degrees and which has a stop mechanism at each limit of rotational movement.

Another object of the invention is to provide an antenna rotating mechanism wherein stop means are provided to limit the rotational movement of the antenna and such stop means includes lost motion means so that at least 360 degrees rotational movement may be achieved. 0 Another object of the invention is to provide a remotely controlled device for rotating an antenna wherein an indicator is provided to indicate the limits of rotational movement of the antenna.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which: 0 Figure 1 is a top or plan view of the antenna rotating device; Figure 2 is a cross sectional elevational view taken along the line 2-2 of Figure 1; Figure 3 is a cross sectional plan view taken 5 along the line 3-3 of Figure 2; Figure 4 is a cross sectional elevation taken along the line 4-4 of Figure 3; Figure 5 is a cross sectional plan view taken along the line 5-5 of Figure 2; Figure 6 is a perspective view of the antenna rotating device attached to a house and carrying an antenna for rotation, and showing the cables connecting the rotator and antenna to the remote control box and television receiver; and Figure 7 is a schematic diagram of the electrical wiring circuit.

The Figure 6 shows an application of the entire invention wherein an antenna rotator assembly 69 is mounted on the roof of a house Sand rotatably carries an antenna 101. The rotator assembly 69 may be remotely controlled at the location of a television receiver 71 by a remote control box 70 which is electrically interconnected with the rotator assembly 69 by the remote control cable 81.

The Figures 1 through 5 may be referred to in order to better understand the construction of the antenna rotator 69. In the drawings, the reference characters II and 12 designate first and second complementary housing shells which are adapted to be placed together to form a complete housing 13. The first and second housing shells II and 12 are adapted to be fastened together by bolts 52 which slide within the bores 53 in the housing shell II and threadedly engage the threaded holes 54 in the second housing shell 12. The housing 13 has a top wall portion 14 and a bottom wall portion 15 for carrying first and second bearings 16 and 17, respectively. A hollow shaft 18 is adapted to be carried by the housing 13 and has first and second bearing portions 19 and 20 journalling with the first and second bearings 16 and 17, respectively. Thus, the hollow shaft 18 may rotate within the housing 13 and relatively thereto. The housing 13 has an end wall 21 for mounting an electric motor 22. A ring gear 23 is fixedly attached exterior of the hollow shaft 18 and within the housing 13 for rotation therewith. A power transmission mechanism interconnects the electric motor 22 and the ring gear 23, and such power transmission mechanism is preferably unidirectional so that the antenna will be locked in a given position when the motor 22 is not rotating.

Thus the force of the wind or other external forces will not cause rotation of the antenna.

Such unidirectional power transmission mechanism has been shown as a gear reduction system 24 and a worm 25 for meshing with the ring gear 23. A terminal wall portion 26 is provided in the lower portion of the housing 13 to provide a terminal box 27 wherein external wiring may be terminated to provide the electric connections to the motor 22.

Stop means 49 are provided for limiting the rotational movement of the hollow shaft 18 relative to the housing 13 and such stop means 49 have been shown in this preferred embodiment as including an abutment or first lug 28 fixedly attached to the hollow shaft 18. The first and 33 second housing shells II and 12 have first and second slot portions 29 and 30, respectively, to provide a continuous slot 31. A stop slide 32 is adapted to slidably engage the continuous slot 31 and has a second lug or abutment 33. The 40I second lug 33 is adapted to cooperate with the first lug 28 as best shown in Figure 5. The length of the continuous slot 31 is preferably made of a dimension that exceeds the sum of the widths of the first and second lugs 28 and 33 so that the hollow shaft 18 may have slightly greater than 360 degrees rotational movement. The continuous slot 31 and stop slide 32 are preferably Tshaped in cross section to provide interlocking engagement therebetween, and thus the stop slide 32 can move only longitudinally, and will not become disengaged from this continuous slot despite any position of the rotator assembly 69. By providing the first and second slot portions 29 and 30 in the two housing shells, the stop slide 32 may easily be inserted in one thereof before assembly, and thence the stop slide 32 will be contained within the continuous slot 31 upon assembly of the two housing shells II and 12. The stop slide 32 sliding within the continuous slot 31 is a lost CO motion connection between the first lug 28 and the housing 13 and, hence, rotational movement of the hollow shaft 18 is not limited to 360 degrees minus the combined arcuate dimensions, relative to the hollow shaft 18, of the lugs 28 and 33, were the lug 33 to be fixedly attached to the housing 13.

In the preferred embodiment, the lost motion means permits approximately 370 degrees rotational movement of the hollow shaft 18. As shown in Figure 6, the antenna shaft 34 is adapted to be inserted within the hollow shaft 18. The hollow shaft 18 has first and second ends 35 and 36, respectively, with U-bolt clamps 37 and 38, respectively, attached thereto. As best seen in Figures 1 and 4, the first and second ends 35 and 36 of the hollow shaft 18 have a slot 39 to receive a portion of the U-bolt clamps 37 and 38.

Thus, the U-bolt clamps 37 and 38 may be tightened by means of the nuts 40 to fasten the antenna shaft 34 fixedly to the hollow shaft 18.

By so providing the slot 39, an antenna shaft 34 which is considerably smaller than the bore of the hollow shaft 18 may still be accommodated and clamped within this hollow shaft. If the antenna shaft 34 is larger in exterior diameter than the bore of the hollow shaft 18, a reducing shaft may be provided and fixedly attached to the antenna shaft 34 to be received within the hollow shaft 18.

The housing 13 has a second end wall 55 to which studs 56 are fixedly attached. Clamp bars 57 are receivable on the studs 56 so that the housing 13 may be clamped to a support shaft 58 as shown in Figure 6. The studs 56 and clamp bars 57 need not be utilized to fasten the housing 13 to a support shaft but may be used to effect an attachment of the housing 13 to any fixed support in any suitable manner.

A signal switch 41 is provided within the housing 13 and is adapted to be actuated at or near the limit of rotational movement of the hollow shaft 18. The signal switch in this preferred embodiment is simply and ruggedly constructed and includes first and second L-shaped switch blades 42 and 43. The switch blades 42 and 43 have terminal portions 44 and 45 for attaching to the terminal wall portion 26 of the housing 13.

This terminal wall portion 26 is preferably an insulator so that the switch blades 42 and 43 need not be insulated therefrom. The switch blades 42 and 43 also have first and second contact portions 46 and 47 which are adapted to mutually contact each other. The hollow shaft 18 has a third lug 48 which is adapted to actuate one or the other of the contact portions 46 and 47 to provide electrical contact between the contact portions 46 and 47. As best seen in Figure 5, the third lug is positioned upon the hollow shaft 18 so that electrical contact will be made between the contact portions 46 and 47, preferably just prior to the limit of the rotational movement of the hollow shaft 18 by the stop means 49. In the preferred embodiment of the invention, such electrical contacting of the blades 46 and 47 is provided between one and three degrees prior to such limit of rotational movement. Terminals 50 and 5I are connected to the terminal portions 44 and 45 within the terminal box 27 so that electrical connection can be made to this signal switch 4i.

A waterproof rubber shield 59 is preferably provided above the upper bearing 16 to aid in providing a waterproof housing and this waterproof rubber shield 59 has been shown as being disposed between first and second collars 60 and 61, respectively, for supporting and positioning such shield. Preferably the first and second housing shells 11 and 12 have the edges 62 and 63, respectively, which are in mutual contact, in a shiplap construction which aids in providing a waterproof structure. Further, during assembly the edges 62 and 63 may be coated with a liquid waterproof agent to seal the juncture of these two housing shells. A cover plate 64 covers the terminal box 27 to enclose this terminal box. A rubber grommet 65 is provided in an aperture 66 in the bottom wall portion 15 to provide cable access to the terminal box 27. A cable clamp 67 may be provided to physically support a cable which contains the wires making electrical connection within the terminal box 27.

A cap 15 is preferably provided at the top of the second end wall SI and has fins 106 for mechanical strength so that this cap 105 may cover the top of the support shaft 58 to keep out rain and also to act as a support to prevent the antenna rotator assembly 69 from sliding down the support shaft 58.

The Figure 6 shows the completed antenna 1( rotator mounted upon a support shaft 58 which in turn is attached in any suitable fashion to a fixed support; in this example, the edge of a roof of a house. It is to be understood that the support shaft 58 may be made of any desirable length in order to place an antenna 101 at the desired height. Also, the antenna shaft 34 may be made of any suitable length, although preferably it is kept short and the antenna rotator assembly is thus placed close to the antenna. The housing 2C 13 is preferably made of aluminum or other lightweight metal, so that the weight of the rotator assembly is kept small, thus reducing the tendency to whip upon the support shaft 58. If the support shaft 58 is made quite long, guy wires may be attached to the rotator assembly and pierced ears 68 have been provided for attaching such guy wires.

By spacing the bearings 16 and 17 in the top and bottom walls of the housing 13, and by placing the clamp means 37 and 38 outboard of these bearings, the complete antenna rotator assembly 69 has considerable strength in comparison to its small size and light weight.

The Figure 7 shows the schematic electrical wiring diagram for providing remote control of the motor 22. In this Figure 7, the reference character 69 indicates the antenna rotator assembly and the reference character 70 indicates the remote control box. The remote control box 70 is also shown in the Figure 6 and Is adapted to be placed near the radio device for which the antenna is being used. In the Figure 6, the antenna has been shown as being used with a television receiver 71 with the remote control box 70 placed thereon for the convenience of the operator of the receiver 71. In Figure 7, the wiring diagram shows that the remote control box 70 includes a transformer 72 having a primary 73 and a secondary 74. A primary switch 75 is adapted to control the energization of the primary 73 from an alternating current source 76. The remote control box has first, se-ond, third and fourth terminals 77, 78, 79 and 80 which are adapted to be connected by a remote control cable 81 to corresponding terminals 82, 83, 84 and 85, respectively, in the terminal box 27 of the antenna rotator assembly 69. A secondary switch 86 is adapted to connect one end 87 of the secondary 74 to either the first or second terminals 77 or 78. This secondary switch 86 is a single pole, double throw switch having first and second contacts 88 and 89 connected to the first and second terminals 77 and 78, respectively. The second end 90 of the secondary 74 is connected 65 1 to the third terminal 79 by conductor 91. An intermediate tap 92 of the secondary 74 is connected by a conductor 93 and an indicating lamp 94 to the fourth terminal 80. The primary and secondary switches 715 and 86 are preferably adapted to be actuated together as shown by the t connecting link 95. A condenser 99 is connected across the first and second terminals 77 and 78. t In the antenna rotator assembly 69, the electric c motor 22 is shown as being an induction motor 75 g having first and second windings 89 and 37. One end of each of the windings 96 and 97 Is connected together at the juncture 98 and the other ends of the first and second windings are connected to the first and second terminals 82 and 83, respectively. The juncture 98 is connected to the third terminal 84 and is connected through the signal switch 41 to the fourth terminal 85.

The condenser 99 has been shown within the re) mote control box 70 to shift the phase of one of the windings 96 and 97 relative to the other in order to provide starting torque and rotation of the electric motor 22 in a governable direction.

The remote control cable 8 has been shown in Sthe Figure 6 and interconnects the remote control box 70 and the rotator assembly 69 at the terminal box 27. Further, in Figure 6 an antenna lead-in 100 has been shown interconnecting the antenna 101 and the television receiver 71. The remote control box 70 has been shown as deriving electrical energy from the alternating current source 76 by a power cord 102 and a wall outlet 103. A power cord 104 is also shown as being connected to the wall outlet 103 and supplies energy to the television receiver 71. The Figure 6 shows the remote control box 70 as having a switch knob 107 for actuating the primary and secondary switches 75 and 86, which switch knob has a neutral position and may be actuated either to the right or left to cause the switch 86 to contact either the contact 88 or 89. Further, the remote control box 70 may have a translucent panel 108 behind which the indicating lamp 94 may be mounted. The translucent panel 108 may be provided with any suitable legend, and in the preferred embodiment, the translucent panel has been provided with a legend reading, "End of rotation, reverse switch." Operation As previously stated, the primary and secondary switches 75 and 86 are interconnected for actuation and the secondary switch 86 is adapted to be closed before the closing of the contacts of the primary switch 75. This permits lighter duty contacts at the secondary switch 86 since it does not Interrupt the heavier secondary current, and further the primary switch 75 being normally open, permits the use of an intermittent duty transformer 72. When the secondary switch 86 is thrown to contact either the first or second contacts 88 and 89 the primary switch 75 is thereupon closed to enervize the transformer 72.

If the secondary switch 86 makes contact through the first contact 88, then the first motor winding 96 will be directly energized and the second motor winding 97 will be energized through the condenser 99 to start the motor 22 rotating in a given direction. If the secondary switch 86 makes contact through the second contact 89, then the second motor winding 97 Is energized directly and the first motor winding 96 is energized through the condenser 99 to provide rotation of the motor 22 in the opposite direction. The motor enerSization circuit is completed through the third terminals 84 and 79 to the second end 90 of the secondary 74. As previously explained, the indicating switch 41 is actuated by the third lug 48 on the hollow shaft 18 and is adapted to be actuated approximately one to three degrees prior to -he limit of rotational movement by the stop means 49. When the signal switch 41 is actuated ;o an electrically closed condition, a circuit is completed through the lower half of the secondary 74, through the third terminals 79 and 84, *the signal switch 41, and the indicating lamp 94 to return to the intermediate tap 92 of the secondary 14. This closed circuit will thus energize the indicating lamp 94 and thus give an indication that limit of rotation of the antenna 101 has been reached.

Thus, the invention provides aj antenna rotator assembly which provides for quick and accurate orientation of an antenna for facilitating the improved reception of a desired signal.

The use of the gear reduction system 24 provides a relatively slow rotation of the antenna 101 and by using the worm 25, the antenna is self-locking in that wind or other external forces will not be able to rotate the antenna. The housing shells II and 12 are preferably made of aluminum castings which provide considerable strength to the rotator assembly and yet provide a light and small structure which does not cause undue strains upon the supporting shaft 58. By providing approximately 370 degrees rotation, the antenna may be oriented to best receive the desired signal. Further, since any antenna is slightly directional and especially those antenna arrays designed to be primarily unidirectional may be oriented to obtain the greatest ratio of desired signal to interference. A directional antenna will have a major lobe and smaller spurious lobes as shown on a horizontal radiation pattern and between such lobes there will -be nulls. By so directing a null toward an interfering station, the maximum ratio of desired signal to interference may be obtained.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangements of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is: 1. A device for providing relative rotational movement between a shaft and a housing, comprising a hollow shaft extending longitudinally through and journalled in said housing to receive said shaft, clamp means near the longitudinal extremities of said hollow shaft adapted to fixedly attach said hollow shaft to said shaft receivable therein, an electric motor and a power train within said housing and interconnecting said housing and said hollow shaft for relative rotation, and means to provide electrical connection to said electric motor.

2. A device for providing relative rotational movement between two shafts, comprising a housing, a hollow shaft extending longitudinally through and journalled in said housing to receive one of said two shafts, clamp means near the longitudinal extremities of said hollow shaft adapted to fixedly attach said hollow shaft to said shaft receivable therein, an electric motor and a power train within said housing and interconnecting said housing and said hollow shaft for relative rotation, means for fixedly attaching said housing to the other of said two shafts, and means to provide electrical connection to said electric motor.

3. A rotator for rotating a device having a shaft comprising, a housing, an electric motor mounted in said housing, a hollow shaft extending longitudinally through and journalled in said housing to receive said shaft of said device, clamp means near the longitudinal ┬░extremities of said housing adapted to fixedly clamp said shaft of said device to said hollow shaft for rotation therewith, power train means for interconnecting said hollow shaft and said electric motor, electrical connection means for said electric motor, and stop means for limiting relative rotational movement between said hollow shaft and said housing, said stop means including an abutment adapted to rotate in accordance with said relative rotation, a second abutment carried by said housing and adapted to cooperate with said first abutment, one of said abutments having a lost motion connection with the element carrying same, such that said relative rotational movement at least equals. 360 degrees.

4. A device for rotating an antenna having a shaft, comprising, a weatherproof housing, a hollow shaft extending longitudinally through and weatherproofly journalled in said housing to receive said antenna shaft, clamp means near the longitudinal extremities of said housing adapted to fixedly clamp said antenna shaft to said hollow shaft for rotation therewith, an electric motor mounted in said housing, power train means for interconnecting said hollow shaft and said electric motor, stop means for limiting rotational movement of said hollow shaft, said stop means including a first lug axially projecting from said hollow shaft, a second lug carried by said housing, and lost motion means including said second lug and disposed between said first lug and said housing.

5. A device for rotating an antenna having a shaft comprising, a weatherproof housing having an end wall, a hollow shaft extending vertically through and journalled in said housing to receive said antenna shaft, a ring gear fixedly attached to and externally of said hollow shaft within said housing, clamp means above and below said housing adapted to fixedly clamp said antenna shaft to said hollow shaft for rotation therewith, an electric motor mounted to said end wall within said housing, gear reduction means including a worm gear meshing with said ring gear for rotating said hollow shaft from said electric motor, stop means for limiting rotational movement of said hollow shaft, said stop means including a first lug axially projecting from said hollow shaft, a second lug carried by said housing, lost motion means including said second lug and disposed between said first lug and said housing, and signal switch actuating means including a third lug radially projecting from said hollow shaft, two substantially parallel spaced spring contact members carried by said housing and adapted to be contacted by said third lug, one of said spring contact members adapted to be contacted by said third lug and urged into contact with the other of said spring contact members near each limit of rotation of said hollow shaft approximately 1 degree to 3 degrees prior to the limit of rotation of said hollow shaft by said stop means.

6. An antenna rotator for an antenna having a shaft, comprising, first and second complementary housing shells interfitting to form a weatherproof housing, means on said housing to fasten said housing to a fixed support, first and second longitudinally opposite end walls in said housing, bearings carried by said end walls, a hollow shaft weatherproofly journalled in said bearings and having first and second ends extending beyond said first and second end walls, respectively, a clamp carried external of said housing by each of said first and second ends to clamp the shaft Of said antenna receivable in said hollow shaft, an electric motor fastened within said housing, a ring gear fixedly attached to said hollow shaft within said housing, unidirectional gear train means including a worm gear meshing with said ring gear for driving said hollow shaft from said electric motor, and terminal connection means for providing electrical connection to said electric motor.

7. An antenna rotator for an antenna having a shaft, comprising, first and second complementary housing shells interfitting to form a weatherproof housing, means on said housing to fasten said housing to a fixed support, first and second longitudinally opposite end walls in said housing, bearings carried by said end walls, a hollow shaft weatherproofly journalled in said bearings and having first and second ends extending beyond said first and second end walls, respectively, a clamp carried by each of said first and second ends external of said housing to clamp the shaft of said antenna receivab'e in said hollow shaft, an electric motor fastened within said housing, a ring gear fixedly attached to said hollow shaft within said housing, unidirectional gear train means including a worm gear meshing with said ring gear for driving said hollow shaft from said electric motor, terminal connection means for providing electrical connection to said electric motor, and stop means for limiting rotational movement of said hollow shaft, said stop means including a first lug radially projecting from said hollow shaft, a slot in each of said housing shells adapted to form one continuous slot, a stop slide engaging and sliding within said continuous slot 3 and having a given longitudinal length, said first lug having a first given width, a second lug on stad stop slide adapted to engage said first lug upon rotational movement of said hollow shaft, said second lug having a second given width, the 4 length of said continuous slot exceeding the length of said stop slide by an amount at least equal to the sum of said given widths to thereby permit at least 360 degrees rotational movement of said hollow shaft. 4 8. An antenna rotator for an antenna having a shaft, comprising, first and second complementary housing shells interfitting to form a weatherproof housing, means on said housing to fasten said housing to a fixed support, first and second longitudinally opposite end walls in said housing, bearings carried by said end walls, a hollow shaft weatherproofly journalled in said bearings and having first and second ends extending beyond said first and second end walls, respectively, a 65 clamp carried by each of said first and second ends to clamp the shaft of said antenna receivable in said hollow shaft, an electric motor fastened within said housing, a ring gear fixedly attached to said hollow shaft within said housing, 6( unidirectional gear train means including a worm gear meshing with said ring gear for driving said hollow shaft from said electric motor, terminal connection means for providing electrical connection to said electric motor, and stop means 68 for limiting rotational movement of said hollow shaft, said stop means including a first lug axially projecting from said hollow shaft, a slot in each -of said housing shells adapted to form one continuous slot, a stop slide engaging said continuous 70 slot, said first lug having a first width establishing a first arcuate dimension relative to said hollow shaft, a second lug on said stop slide adapted to engage said first lug upon rotational movement of said hollow shaft, said second lug having 15 a second width establishing a second arcuate dimension relative to said hollow shaft, a given angle being established by 360 degrees less the sum of said first and second arcuate dimensions, said stop slide having a lost motion connection with said continuous slot such that the rotational movement of said hollow shaft exceeds said given angle.

9. A device for rotating an antenna shaft relative to a fixed support, comprising a first member adapted to be fixedly attached to said fixed support, a second member revoluble relative to said first member, an electric motor and a power train interconnecting said first and second members, electricalmeans carried by one of said members, said electrical means having two electrical connections and operable to produce a changed electrical condition across said two electrical connections, second means carried by the other of said members for operating said electrical means, terminals adapted to be connected to a source of electrical power, and an indicator connected in circuit with said terminals and the two electrical connections of said electrical means for indicating at least one rotational position of said second member.

10. A device for rotating an antenna shaft relative to a fixed support, comprising a first member adapted to be fixedly attached to said fixed support, a second member revolub'e relative to said first member, an electric motor and a gear train interconnecting said first and second members, first and second abutment means on said first and second members respectively, lost motion means disposed between said abutment means, stop means including said abutment means and said lost motion means to limit the rotation of said second member to approximately 360 degrees, indicator switch means including at 0 least one of said abutment means and said lost motion means and actuable at least at said rotational limits, terminals adapted to be connected to a source of electrical power, and an electrically operated indicator connected in loop circuit 5 with said terminals and said indicator switch means to indicate at least said rotational limits.

11. A device fo" rotating, an antenna shaft relative to a fixed support, comprising a first member adapted to be fixedly attached to said 0 fixed support, a second member revoluble relative to said first member, an electric motor and a gear train interconnecting said first and second members, an abutment on said second member, switch means fixed relative to said first member and 5 actuable by said abutment from either of the two rotational directions, the combination of said abutment and said switch means having a lost motion connection to establish actuation of said switch means substantially at either end of 360 0 degree rotational movement of said second member, terminals adapted to be connected to a source of electrical power, and an indicator connected in loop circuit with said terminals and said switch means to indicate the limits of rotational Smovements of said second member.

12. A device for rotating an antenna having a shaft comprising, a weatherproof housing having an end wall, a hollow shaft extending vertically through and journalled in said housing to receive said antenna shaft, a ring gear fixedly attached to and externally of said hollow shaft within said housing, clamp means above and below said housing adapted to fixedly clamp said antenna shaft to said hollow shaft for rotation* therewith, a reversible electric motor mounted to said end wall within said housing, gear reduction means including a worm gear meshing with said ring gear for rotating said hollow shaft from said electric motor, a transformer adapted to be energized from an alternating current source, primary switch means for controlling the energization of the transformer primary from said alternating current source, secondary reversing switch means controlling the energization of said motor from said transformer secondary for forward and reverse rotational movements, signal switch means in said housing, actuating means on said hollow shaft for actuating said signal switch means at either end of substantially 360 degree rotational movement of said hollow shaft, stop means for limiting rotational movement of said hollow shaft to approximately 360 degrees, a signal light for indicating either end of substantially 360 degree rotational movement of said antenna shaft, and connection means including 2o at least a part of said transformer secondary for energizing said signal light upon closing of said signal switch means.

13. A device for rotating relative to a fixed support an antenna having a shaft comprising, a weatherproof housing having an end wall, a hollow shaft extending vertically through and journaled in said housing to receive one of said antenna shaft and said fixed support, means for fixedly attaching said housing to the other one of said antenna shaft and said fixed support, clamp means above and below said housing adapted to fixedly clamp said one of said antenna shaft and said fixed support to said hollow shaft for rotation therewith, a ring gear fixedly attached to and externally of said hollow shaft within said housing, an electric motor mounted to said end wall within said housing, gear reduction means including a worm gear meshing with said ring gear for rotating said hollow shaft from said electric motor, signal switch means in said housing, and actuating means on said hollow shaft for actuating said signal switch means at either end of substantially 360 degree rotational movement of said hol- 4.5 low shaft.

14. A device for rotating an antenna shaft relative to a fixed support, comprising a first member, a second member revoluble relative to said first member, one of said members being hollow to receive one of said antenna shaft and said fixed support, an electric motor and a power train interconnecting said first and second members, electrical means carried by one of said members, said electrical means having two electrical con- j55 nections and operable to produce a changed electrical condition across said two electrical connections, second means carried by the other of said members for operating said electrical means, terminals adapted to be connected to a source of electrical power, and an indicator connected in circuit with said terminals and the two electrical connections of said electrical means for indicating at least one rotational position of said second member. 15. A device for rotating an antenna shaft relative to a fixed support, comprising, a first member adapted to be fixedly attached to said fixed support, a second member revoluble relative to said first member to rotate said antenna shaft, 71 an electric motor and a power train interconnecting said first and second members to rotate said second member, electrical means carried by said first member, said electrical means having two electrical connections and operable to produce a changed electrical condition across said two electrical connections, second means driven from said power train for operating said electrical means, terminals adapted to be connected to a source of electrical power, and a position indicator controlled by a circuit including said terminals and the two electrical connections of said electrical means.

16. A device for rotating an antenna shaft relative to a fixed support, comprising a first member adapted to be fixedly attached to said fixed support, a second member revoluble relative to said first member, an electric motor and a power train interconnecting said first and second members, electrical means carried by one of said members, second means carried by the other of said members for operating said electrical means, the combination of said electrical means and said second means having two electrical connections and operable to produce a changed electrical condition across said two electrical connections, terminals adapted to be connected to a source of electrical power, and an indicator connected in circuit with said terminals and the said two electrical connections for indicating at least one rotational position of said second member.

17. A device for rotating an antenna shaft relative to a fixed support, comprising, a first member adapted to be fixedly attached to said fixed support, a second member revoluble relative to said first member to rotate said antenna shaft, an electric motor and a power train interconnecting said first and second members to rotate said second member, electrical means carried by said first member, second means driven from said power train for operating said electrical means, the combination of said electrical means and said second means having two electrical connections and operable to produce a changed electrical condition across said two electrical connections, terminals adapted to be connected to a source of electrical power, and a position indicator controlled by a circuit including said terminals and the said two electrical connections.

RICHARD H. JORDAN.

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