US2745994A - Antenna position control means and indicator - Google Patents

Description

y 15, 1956 P. A. DICKE ETAL ANTENNA POSITION CONTROL MEANS AND INDICATOR Filed May 12 I I I l I l i /6 l l l l l I @aw? Cl. JQLoPm ANTENNA POSITION CONTROL MEANS AND INDICATOR Paul A. Dicke, New Bremen, Ohio, and Allen A. Dicke,

Montclair, N. 3., assignors to Crown Controls =Com- -pany, Inc., New Bremen, hio, acorporation of Ohio .Application May 12, 1951, Serial No. 226,032 9 Claims. (Cl. 31818) This invention relates to antenna position indicators, and more particularly to improved means for remotely indicating and observing the movements and position of the antenna.

Antenna rotator indicators have heretofore been known but in a relatively complicated form wherein potentiometers, electrical bridges and like devices and circuits have been used to indicate to'the operator at his'telcvision orradio receiver the position of the remote antenna which is out of his sight.

The object of the invention is to simplify the construction as well as the means and mode of operation of antenna rotators together with position indicator mechanism, whereby such rotators may not only be economically manufactured, but will be more'efiicient and satisfactory in use, having relatively few parts and be unlikely to get out of repair.

A further object of this invention is to obviate the complication described through the use of an indicating apparatus wherein an electrically con-trolled dial pointer is made substantially directly responsive to mechanical following devices associated with the rotatable antenna mast.

--Another object of the invention is to present a generally new antenna rotating apparatus particularly characterized by ease and reliability of operation and by accurate dial indication.

' A further object of the invention is to utilizeaprinciple of thermally initiated dial indication in conjunction with antenna rotating and following devices.

' A further object of the invention is to-provide such a remote position indicator which is not' afiected by voltage fluctuation in the energizing circuit.

A further object of the invention is to provide such a remote position indicator which is not affected by variations in the resistance of the various connecting conductors.

A further object of the invention is to provide a rotator embodying adjustable linkage intermediate the=rotator proper and the indicating mechanism to permit adjustment' of the unit without'affecting the accuracy of the indicating mechanism.

A further object of the invention is to provide an antenna rotator possessing the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein mentioned.

With the above primaryand other incidental objects in viewas will more fully'appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation, as hereinafter described or illustrated in-the accompanying drawings, or their equivalents.

2,745,994 Patented May 15, 1956 Referring to the accompanying drawing, wherein is shown the preferred but obviously not necessarily the only form of embodiment of the invention,

Fig. 1 is a diagrammatic view of an antenna rotating apparatus illustrating the invention;

-'Fig. 2 is a schematic view of a portion of the indicating mechanism in one extreme position;

Fig. 3 is a view similar to Fig. 2 showing a portion of the indicating mechanism in the opposite 'extreme'position.

Like parts are indicated by similarcharacters ofreference throughout the several views.

Referring to the drawings, an antenna 10 is diagram matically indicated as made fast to a mast 11 represented as an extension of a rotor 12 of a reversible electric motor 13, shown as of the capacitor-run type. In response to rotation of the rotor 12, therefore, the mast 11 is rotated and the antenna 10 thereby turned.

--The motor 13 further includes spaced field windings 14- and 15 having commonconnection at their-one end with an electrical conductor 16 and individual connection at their opposite end with parallel leads 17 and 18. A capacitor 19 is connected across the loads 17 and 18. 7 Electrical current for operation of the motor 13 is derived from a suitable power source from which extend conductors 21 and 22, in one of which is a main control switch 23, the conductors 21- and 22 being connected to the-primary of a transformer 24. To one end of the secondary of transformer 24 is connected the common conductor 16 while to the other end thereof is connected a conductor 25 terminating in a single pole double throw switch 26.

The switch 26 is adjustable from an intermediate normal position to optional engagement with respective terminals 27 and 28 on the leads 17 and 18. Accordingly,

the switch 26 is a directional control since by its adjustment the circuit may be optionally closed through the leads 17 or 18 with the result that either winding 14 or '15 is'directly energized and the direction of motion of and one shorter blade, normally closed, with the longer blade extending into the path of a respective tab 32 and '33 on an extension 34- of the rotor 12. It will be apparent from the construction and arrangement of parts that the rotor extension 34 can move within a range of approximately 360. At the extremes of such range either the switch contact 29 or the switch contact 31 will i be engaged by the tab 32 or 33 with the result that the switch blades are separated and current flow through the motor 13 accordingly interrupted.

It will be understood, of course, that the antenna mast 11 and the shaft 56 with the limit switch control members 32, 33, 34, thereon, are not in practice direct extensions of the shaft of rotor 12 but instead aredriven by the rotor 12 through suitable reduction gearing.

A lamp 35 is connected in the secondary of the transformer 24 through leads 36 and 37. It is thus illuminated in response to the closing of switch 23 and gives a visual i signal or indication that the apparatus is conditioned for turning of the antenna, this being accomplished by moving the switch 26 to engage terminal 27 or terminal28 :according to the direction ofantenna rot-ationldesired.

For remote observation of the position of the antenna there is provided a dial 38 on which the points of the compass are arranged in arcuate series, the letter N appearing at each end of the series as the north position may be reached by rotation in either direction. The dial 38 is traversed by the outer or free end of an indicator pointer 39 which is attached at its opposite or base end for pivotal swinging motion. The movements of the pointer 39 are effected and controlled by a thermally sensitive bimetal element 41 connected to the pointer by a link 42. The element 41 has a fixed base 43 and is flexed about such base to cause the pointer 39 to assume normally a position at the extreme left hand end of the dial 38. Surrounding the element 41 is a resistance coil 44 in an electrical lead 45--45', energizing of the coil 44 serving to heat the element 41 to initiate motion thereof from the normal flexed position and so move the pointer 39 over the dial 38.

The electrical lead 45 is connected to the transformer through lamp conductor 37, while lead 45 terminates in a contact 46 on a lever 47. A mating contact 48 is positioned on another flexible bimetal element 49 constructed and mounted like the element 41. A resistance coil 51 surrounds the element 49 and interconnects the contact 48 with the transformer through the common motor conductor 16. The construction and arrangement of parts, it will be noted, is such that closing of the main switch 23 will close a circuit through the resistance coils 44 and 51 when the contacts 46 and 48 are engaged or closed.

The lever 47, carrying contact 46, is arranged for pivotal swinging motion about its base end. Its outer or free end is connected by suitable means, such as a link 52 to an arm 53 presenting a stud 54 riding the periphery of a cam 55 fast on a shaft 56 represented as a projection of the rotor extension 34. The cam 55 is so formed that revolution thereof in one direction, within the limited range of operation of the motor, rocks arm 53 outward or in a directionto shift lever 47 toward the bimetal element 49, return of the cam in the opposite direction allowing a reverse or return motion of the arm 53 and lever 47 under the influence of a spring 57.

The bimetal element 49 has a normal or initial flexure toward the lever 47. The contacts 46 and 48 accordingly are normally engaged, with the bimetal element 49 having a greater or lesser tension imposed thereon by the lever 47 in accordance with the position of the cam 55. Under the heating influence of the coil 51, the element 49 will move in a direction to separate the contacts 46 and 48, the duration of the heating period being determined by the degree of tension under which the element 49 is held, and, therefore, by the position of cam 55. When the contacts 46 and 48 are separated, the circuit through the coil 51 is broken but will immediately be reestablished as the element cools and moves under its inherent resilience to reengage the contact 48 with the contact 46. In response to such reengagement, the coil 51 is again energized and the element 49 again heated to disengage the contacts 46 and 48, this repeated engagement and disengagement of the contacts continuing at a relatively high frequency so long as the switch 23 remains closed. During the initial period of engagement between the contacts 46 and 48, the resistance coil 44 is, like the coil 51, continuously energized. Accordingly, the bi metal element 41 is heated and moves to draw the pointer 39 over the dial 38. This motion will continue until the pointer reaches a place on the dial substantially corresponding to the position of the cam 55, at which time the contacts 46 and 48 separate and interrupt current flow through both coils 44 and 51. Through the subsequent repeated engagement and disengagement of the contacts 46 and 48, the pointer 39 maintains its position, although it will partake in some degree in the almost undistinguishable fluctuation of the element 49.

Such a remoteindicating mechanism has the further important advantage that the indication is independent of fluctuations in supply voltage, and in line resistance. For any given setting of contact 46 the indicator 39 will have a corresponding position. If the voltage supplied to the indicator circuit drops the average time of engagement of contacts 46 and 48 will be correspondingly increased; or decreased if the supply voltage rises. It is merely necessary that the average current flowing in coil 51 is just sufficient to relieve the initial stress therein. This requires a certain temperature rise in bimetal arm 49. Since the current flowing in heater coil 51 also flows in heater coil 44 the deflection of bimetal 41 and of pointer 39 will correspond to the position of contact 46 and this result is independent of the voltage supply, within very large limits, and is also independent of variation in the resistance of the connecting conductors 16 and 45.

While any suitable means may be employed for adjusting the position of contact 46 relative to contact 48 in accordance with the position of the antenna mast 11, the use of a spiral cam, such as the cam 55, has been found acceptable. By continuing the spiral beyond one turn, as shown at 55', it is possible to provide a certain amount of adjustment between the shaft 56 and the contact 46 by rotarily adjusting the cam on the shaft.

The apparatus is ordinarily comprised of two units A and B interconnected by the several electrical conductors, housed in a cable 59 as suggested in Fig. 1. Unit A occupies a position adjacent the antenna and comprises the motor 13 and associated parts including the cam 55, follower arm 53 and control parts 47 and 49. Unit B is made portable to be accessible in connection with operation of the television or radio receiver and comprises the transformer 24, control switches 23 and 26, signal lamp 35, dial 38 and the dial indicating mechanism.

When the apparatus is not in operation the switch 23 is normally open and the switch 26 occupies a position intermediate and out of contact with either terminal 27 or 28. Further, the bimetal element 41 is flexed to place the pointer 39 at the left hand or starting place on the dial 38 and the element 49 is flexed to engage contact 48 with contact 46, the degree of tension of the element 49 being a function of the position of the cam 55. Closing of the switch 23 does not initiate operation of the motor 13, without an operating adjustment of the directional switch 26, but will result in lighting the lamp 35 and in closing the circuit through the resistance coils 44 and 51. In response thereto, the pointer 39 begins to climb upward on the dial 38, and, at the same time, the bimetal element 49 is subjected to heat, ultimately effective as the tension under which the element is held is relieved, to withdraw contact 48 from contact 46. At the time of such withdrawal, the pointer 39 will have reached a point on the dial 38 corresponding to and indicating the position of the antenna. The parts will remain substantially in this position as long as the switch 23 remains closed, the contacts 46 and 48 vibrating between open and closed position to substantially prevent descent or further climbing of the pointer 39 from the position initially gained.

Now, if it is desired to change the position of the antenna, the switch 26 is pushed in the appropriate direction to close the motor circuit through lead 17 or lead 18. As the rotor 12 turns to effect the desired readjustment of the antenna, the cam 55 is turned correspondingly and such motion followed by the arm 53 and lever 47 carrying the contact 46. A swinging motion of the lever 47 accordingly results and the contact 46 is moved toward or away from the contact 48 in accordance with the direction of motion of the cam 55. If the motion is toward contact 48 an added tension is imparted to the element 49 and the coil 51 remains energized until such added tension is relieved, the pointer 39 climbing during such period to a higher place on the dial. If the motion is away from contact 48, a cooling period results while the element 49 moves to overtake the lever 47 and there is will .resume its heat-cool vibratory movements, stabilizing the pointer 39 in its new position of adjustment. All the indicating mechanism parts are returned to normal upon opening of the main switch 23.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into effect.

Having thus described our invention, we claim:

1. In a reversible antenna rotator of the type wherein motor means is operatively connected with an antenna mast for rotating said mast, an electrical control circuit for said motor means including alternative leads to the windings of said motor means and a common lead therefrom, a main switch in said circuit, a supplemental switch for closing the circuit selectively through said alternative leads, an antenna position indicator, a thermal element connected to said indicator and flexed to define a normal or starting position therefor, a resistance coil in said circuit for heating said thermal element to move said indicator away from normal position in response to closing of said main switch, and control means in said circuit responsive to operation of said motor means for interrupting current flow through said resistance coil.

2. In a reversible antenna mast rotator having electric motor means, an electrical control circuit for said motor means including a main switch, an indicator pointer, a thermal element connected to said pointer and flexed to define a normal or starting position for said pointer, a resistance coil in said circuit responsive to closing of said switch to heat said thermal element to produce a motion thereof away from starting position, a follower for said mast, another thermal element flexed to engage said follower and having varying degrees of tension imparted thereto in accordance with the position of said follower, a resistance coil in said circuit for heating said other thermal element to produce motion thereof in a direction to disengage said other element from said follower, and mating electrical contacts on said follower and said other thermal element connected through respective resistance coils to opposite sides of said circuit.

3. In a reversible antenna rotator of the type wherein an antenna mast is rotated by electric motor means, follower means assuming various positions corresponding to the positions of said mast, a thermal responsive element nonnally biased to engage said follower means and having varying degrees of tension imparted thereto in accordance with the position of said follower means, an electrical resistance coil arranged to heat said thermal responsive element to produce motion thereof in a direction to disengage said element from said follower means, an electrical circuit for energizing said motor means, an electrical connection across the opposite sides of said circuit including said coil and mating electrical contacts on said follower means and said element, and directional indicating means operated in response to the wopening and closing of the circuit through said electrical connection.

1 4. A reversible antenna rotator according to claim 3,

characterized in thatsaid last named means comprises a dial, a pointer arranged to traverse said dial, a second thermal element connected to said pointer and flexed to define anormal or starting position for said element, and a second electrical resistance coil interposed in said electrical connection and arranged to heat said second thermal .element to produce a motion of said pointer away from normal position across said dial in response to closing of the circuit through said connection.

5. In a reversible antenna rotator of the type wherein an antenna mast is rotated by electric motor means having opposed field windings, an electrical circuit including a source of electrical power, a transformer the primary of which is connected to the source of electrical power through a main switch, a common connection from one side of the secondary of said transformer to the windings of said motor means, another connection from the opposite side of said secondary, a single pole double throw switch at the terminus of said other connection, alternative connections selectively interconnected by said switch with said other connection and leading to respectively different windings of said motor means, a further connection from said common connection back to said secondary, first and second heater coils arranged in series relation in said further connection, first and second bimetal elements arranged to be heated by the respective coils, said elements being normally biased in a direction opposite to their direction of motion under influence of the heater coils, an indicator pointer operatively connected to the first one of said bimetal elements, a pair of movable contacts interposed in said further connection for making and breaking the circuit therethrough, one of said contacts being mounted on the second one of said bimetal elements, and follower means associated with the rotor of said motor means carrying the other of said movable contacts.

6. A reversible antenna rotator according to claim 5, characterized in that said follower means is arranged to present the contact thereon for engagement by the contact on said second bimetal element, said second element having a varying degree of tension in accordance with the position of said follower means to thereby vary the length of time the circuit through said further connection is held continuously closed after closing of said main switch.

7. In an antenna rotator of the type including electromagnetic means for turning the rotator in either direction at will including a rotatable member, and a control instrument for said electromagnetic means located at a distant point and including a switch for controlling said electromagnetic means, the combination of a followercontrol unit adjacent said electromagnetic means including an adjustable contact cooperating with a contact movable by a thermoresponsive element in such a way that increase of temperature thereof causes its contact to move away from said adjustable contact, a heating element adjacent said thermoresponsive element, a thermal indicator and an electric power source located in said control instrument, electrical conductors connecting said power source, indicator and heater unit in series, and means actuated by said rotatable member for adjusting the position of said adjustable contact, whereby the indicator will assume positions corresponding to and indicating the rotative positions of said rotatable member and antenna.

8. The combination according to claim 7, in which the connection from the rotatable member to the adjustable contact comprises a spiral cam carried by said rotatable member and a cam follower connected to for adjusting said adjustable contact.

9. The combination according to claim 7, in which the able relative to said rotatable member. 5

References Cited in the file of this patent UNITED STATES PATENTS 2,275,237 Smulski Mar. 3, 1942 Smulski Mar. 12, 1936 10 8 Mims Aug. 11, 1942 Jordan Feb. 28, 1950 Smulski Aug. 29, 1950 Hammond Dec. 26, 1950 Blease et a1. July 3, 1951 OTHER 7 REFERENCES Publication: Radar System Fundamentals, Navships 900,017 (page 312).

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