US2496485A

US2496485A - Remote control and indicating system

Info

Publication number: US2496485A
Application number: US692393A
Authority: US
Inventors: Joseph T Mcnaney
Original assignee: Bendix Aviation Corp
Current assignee: Bendix Aviation Corp
Priority date: 1946-08-22
Filing date: 1946-08-22
Publication date: 1950-02-07
Anticipated expiration: 1967-02-07

Description

Feb. 7, 1950 J. T. MONANEY 2,496,485

REMOTE CONTROL AND INDICATING SYSTEM Filed Aug. 22, 194

VOLTAGE CONTRO l STATION REMOTE STATION ACTUATED MECHANISM D. c. VOLTIAGE J OS E PH T. MQN AN EY Gum;

directive movement.

Patented Feb. 7, 1950 REMOTE CONTROL AND INDICATING SYSTEM Joseph '1. McNaney, Baltimore, MIL, assignor to Bendix Aviation Corporation, 'Iowson, MIL, a

corporation of Delaware Application August 22, 1946, Serial No. 692,393

12 Claiml. (01. 318-18) This invention relates to remote control and indicating systems, more particularly to systems which provide control by electrical coupling to actuate a remotely located mechanism to a desired position or station, and provide repeatback means for indicating at the control station the position of the actuated mechanism.

A variety of weaknesses are inherent in previous electrically energized remote control systems.

One weakness is the requirement of added com-' ponent units such as amplifiers for servo" systems, or power packs for energy conversion in case more than one form of operating current is required. Another weakness is the inability of some systems to function rapidly and, at the same time, be adequately responsive to the minute adjustments required in certain applications. In some applications of remote control the remote drive does not accurately follow the local Similarly, the lag of the remote drive often resolves to hunting at the end of an adjustment operation. I

An object of this invention is to provide a system for local control of a remote position or station selecting mechanism, and feed-back indication of that position, which functions entirely from a direct current voltage source.

Another object of this invention is to provide such a system which develops high torque.

Still another object of this invention is to provide such a system in which the remote drive follows the local control with positive synchronism at any speed within the limits of normal operation.

A further object of this invention is to provide such a system in which the speed of the remote drive can be readily controlled to provide maximum position coverage with a minimum of time.

Another object of this invention is to provide such a system in which the desired station or position is selected and retained with positive stability.

Still another object of this invention is to provide such a system which requires a minimum of installation space at both the remote and local positions, and which requires no separate units for its operation.

In accomplishing these objects step-by-step switches in the form of commutators are used in conjunction with reversible direct current motors equipped with electromagnetic clutches and fast-stopping brakes. A compound gear ratio provides adequately small steps for position adjustment as well as extra high torque at the load.

Other objects and advantages of this invention will become apparent from a consideration of the following specification when taken in conjunction with the accompanying drawing in the single figure of which is shown a schematic diagram of a remote control and indicating system embodying the invention.

The objects and advantages of the invention are realized by a system employing a motor to drive the remotely located mechanism, the motor being energized in a step-by-step fashion through a pair of commutators, one located at the control station and crank-driven, and the other located in the remote station and driven by the motor through a magnetic clutch and brake which provides fast stopping of the remote commutator upon the interruption of the motor energizing circuit. Suitable gearing is provided between the crank and the motor and their respective driven devices to provide desired step values and torque at the driven mechanism. A sense switch is incorporated in the crank drive.

A centrifugal switch carried by the remote commutator operates upon rotation of that commutator in excess ofa certain speed to provide continuous excitation of the motor for high speed actuation of the remote mechanism. Repeatback indication of the position of the actuated mechanism is provided by means including a motor positioned at the control station and driving a dial pointer, the motor being energized in a step-by-step fashion through two commutators, one driven by the remote mechanism driving motor and the other driven by the repeatback motor through a magnetic clutch and brake. Gear drive ratios are selected to prevent lag between the commutators and a warning means is provided to indicate any misalignment which might occur between the commutators due to faulty brush contacts.

Referring now more particularly to the drawing, which is divided into two portions by the dashed line A-B, the portions representing a control station and a remote station, as indicated, there is shown a crank I 0 located in the control station and mechanically connected to a resilient member 3| which acts as the switch arm of a sense switch I! and is mounted for rotation with a shaft I4. Likewise mounted for being connected to slip ring 21 and contact 45 being connected to slip ring 25. Member 3| is connected to slip ring 23. Movement of the crank H! in either direction will flex the member 3| until it establishes contact with either contact 42 or contact 45, whereupon further rotation of the crank will, by the application of torque through the members 3| and 38, cause rotation of shaft l4.

A D. C. motor l8, located in the remote station, is energized through a lead II from a source of direct current and drives a commutator 22 and an actuated mechanism 28 through a magnetic clutch and brake 20.

The clutch and the brake 20 may be of the type disclosed in U. S. Patent 2,267,114 for Electro-magnetic clutch, issued December 23, 1941, to Lear et a1. clutch plate 35 and a clutch plate 31, the latter being normally spring pressed into braking engagement with the braking surface 39 carried by a rigid support. Upon the passage of current through coil l of lead during the energization of the motor i9, the two clutch plates are urged into clutching relationship, the plate 3! alone being movable. Upon interruption of current flow through the lead I I, the plate 31 is immediately urged into braking contact with braking surface 39, stopping the shaft-carrying commutator 22 and actuated mechanism 28 almost instantly, the motor i8 continuing to coast to a stop. The energizing circuit of motor |8 includes the exciting coil H, the terminals of which are connected respectively to slip

rings

25 and 21 of the sense switch |2. The sense switch l2, by virtue of the resiliency of member 3|, remains open in the absence of any actuation of the crank l0. However, movement of the crank ID in either direction, causing member 3| to make contact with one of the contacts 42 or 48, thus determines the direction of current flow through the exciting coil l1 and consequently determines the direction of rotation of motor l8.

The mechanical connection i4 between the switch l2 and the commutator I 6 may include gearing designed to give any desired ratio of rotational movement of the commutator I 6 with respect to the crank i0. Likewise the commutator l6 may be provided with any desired number of segments, being shown here as having eight segments 4|. Two

slip rings

45 and 41 are provided, the commutator segments 4| being connected to the slip rings in alternation. Electrical connections are established between the commutator 6 and the commutator 22 by two leads 5| and 52 terminating at the commutator l6 and

brushes

49 and 50 co-acting respectively with the

slip rings

45 and 41. The commutator 22 is provided with four segments connected in alternation to two

slip rings

55 and 56, the leads 5| and 52 terminating in brushes 53 and 54 coacting with the slip rings. A lead l3 connects the commutator 22 with th source of direct current, terminating at the commutator 22 in a brush 58.

The commutator 22 is provided with a centrifugal switch 24, which upon rotation of the commutator 22 in excess of a predetermined speed, closes, cross-connecting the leads 5| and 52 and thus establishing continuous excitation of the motor l8 when the crank I0 is turned in excess of a certain speed.

The mechanical connection between the commutator 22 and the actuated mechanism 28 may be provided with gearing designed to give the de- The clutch consists of a sired ratio of commutator movement to movement of the actuated mechanism. This gearing, together with that between thecrank-driven switch |2 and commutator l5, may be so designed, and may be varied, as to give any desired number of motor exciting impulses per unit of angular or rotational movement of the actuated mechanism.

For the purpose of providing repeat-back information as to the position of the actuated mechanism, a commutator 30 driven by the motor II is provided in the remote station. The commutator 30 is provided with four segments 60, SI, 62 and 63 connected respectively to four slip rings 54, 65, 6E and 61. The commutator 30 is electrically connected to a commutator 40 located in the control station, by four leads BI, 82, 83 and 84. The commutator 40 is provided with four segments 68, 69, ill and 1| corresponding to the segments in commutator 30 and connected to separate slip rings. The leads 8|, 82, 93 and 94 co-act with the slip rings of

commutators

30 and 40 in a manner to maintain connection between respective corresponding segments of the two commutators.

The commutator 40 is mechanically driven by a motor 34, which is similar to the motor l8, through an electro-magnetic clutch and brake 36 which is of the same type as the clutch and brake 20. The motor 34 also mechanically drives a dial pointer 89 co-acting with a dial 88, for the indication of the position of the actuated mechanism. Positioned about the periphery of the commutator 40, in contacting relation with three adjacent segments thereof are brushes l2, l3 and 14..

Brushes I2 and 14 are connected by leads 90 and 5| to the terminals of exciting coil of motor 34. Four

resistors

15, 16, i1 and 18, of equal values, are serially connected between leads 90 and 9|. The junction point of resistors 15 and i1 is connected to the brush 13. Connected between the junction point of resistors I5 and I8 and the junction point of resistors 11 and I8 is a solenoid 19, comprising a pair oi coils 93 and 94, a corresponding terminal of each being connected to the above mentioned junction points and the remaining terminals being connected together and to a lead 81- A flag 49 actuated by solenoid 19 i so mounted that in the absence of such actuation it lies in invisible relationship to an opening 93 formed in a panel 92 visible to the operator. Energization of the motor 34 is completed through the lead 51 and a lead 86 terminating in a brush 85, in contacting relation with commutator 30, which leads may be connected through the same D. C. voltage source as utilized for the motor I8.

Proceeding now to the operation of the system, an operator desiring to cause rotation of the actuateed mechanism turns the crank ID in the direction in which he desires such rotation to take place. Supposing such movement to be desired in the clockwise direction, displacement of the crank in this direction causes the member 3| to make contact with contact 45, thus completing the circuit through'the coil I! in such a direction as to cause clockwise rotation of the motor I8. The energization of the motor I! actuates the electro-magnetic clutch and brake 24 with consequent rotation of the commutator 22 and the actuated mechanism 28. Rotation of the crank causes corresponding or related rotation of the commutator IS in the same direction, the electricalconnections between the commutators l6 and 22 regulating the energization of the motor IS, in a manner determined by the relative number of segments of the eommutatorsi6 and 22 and the drive ratio between the motor I! and the commutator 22, to cause the speedof rotation of the motor l8 to correspond to the speed of the commutator i8 and to vary therewith. On the rotation of the crank ill at'a speed above a predetermined limit the centrifugal switch 24 is closed, thus providing continuous excitation of the motor i8 to its characteristic speed under such excitation. After the motor II has attained its characteristic speed it will continue at that speed if the rotation of the crank is reduced below the predetermined speed referred to above, or even stopped, so long as the member ll is maintained in contact with contact 48. In ortuating mechanism 28.

As has been stated, the gear ratio between the crank-driven switch l2 and the commutator l6 and that between the commutator 22 and the actuated mechanisms 28 may be selected together with the number of segments in the commutator ii to give the desired number of steps of motor energization for each unit ofrotation of the actuated mechanism. By way of example, with a gear ratio of 1 to between the switch I! and the commutator l6 and a gear ratio of 3600 to 1 between the commutator 22 and the actuated mechanism 28, 60 turns of the crank l0 would,

produce 7200 steps of motor excitation which would correspond to 180 degrees of rotation of the actuated mechanism 28, which might, for example, be a condenser.

When the motor l8, and therefore the commutator 30, are at rest, the commutator 48 will be so positioned that the segment lying under neutral brush 13 is connected to the segment of commutator 30 which lies under the brush 85. When rotation of motor i 8 is initiated in the clockwise or counterclockwise direction, segment 52 or 60, respectively, of the commutator 30 will be brought under the brush 85. If the segment 62 is brought under the brush 85 the positive lead 86 will be connected to the segment 89 of the commutator and the motor 34 will be energized in a manner to bring the segment 69 under the neutral, brush 13 whereupon the commutator III will be instantly stopped by the operation of the electro-magnetic clutch and brake 36. Ii the segment 80 of commutator 30 is brought under the brush 85, the segment ll of the commutator 40 will be connected to the positive side of the line and the motor will be driven in the Opposite direction to bring segment H under neutral brush I3, whereupon the motor will again be stopped.

It is possible to select a gear ratio between the motor 34 and the commutator 40 which will not I permit the commutator" to lag behind the comand, as a result, solenoid I9 will be de-energized,v

thus permitting the flag 8 to fall into visual position within the opening 98 of the panel 92 and warning the operator that such misalignment has occurred.

Gear ratios may be selected as desired between

commutators

22 and 88, and between commutator l0 and pointer 88, to give the desired amount of pointer movement per unit of rotation of the actuated mechanism 28. Suppose, for example,

'that the gear ratios mentioned above ar in use and it were desired to have the pointer 88 moved 34 can be stepped up above that of the commutator 40 such, for example, as by ratio of 10 to 1. Other gear ratios may be selected to suit the needs of the user, the system being capable of extreme flexibility in this respect.

While the disclosure has been restricted to that form of the invention which is now preferred, the invention is not to be considered as restricted thereto, since many changes in form and arrangement falling within the scope of the invention as defined by the appended claims, will occur to those skilled in the art.

What is claimed is:

1. A system for positioning a remotely located mechanism from a control station which comprises; a motor driving said mechanism, a circuit for the energization of said motor, said circuit comprising a first commutator located in said control station, means in said control station for driving said commutator, said means controlling the sense of application of exciting energy to said motor through said energizing circuit in accordance with the direction of rotation of said commutator, a second commutator driven by said motor and forming part of said energizing circuit, said. first and second commutators being electrically connected, whereby upon the operation of said commutator driving means said motor will be energized by sequential impulses to a speed and direction 01' rotation which are functions of the speed and direction of the rotation of said driving means, means operable by contrifugal -force generated upon the rotation of said driving means in excess of a predetermined speed to provide continuous excitation of said motor, and means operable upon the interruption of said energizing circuit to disconnect said motor from said second commutator and said mechanism and to stop the rotation of said mechanism.

2. A system for positioning a remotely located mechanism from a control station which com-' Y prises; a motor driving said mechanism, a circuit for the energization of said motor, said circuit comprising a first commutator located in said control station, means insaid control station for. driving said commutator, said means controlling the sense of the application of exciting energy to said motor through said energizing circuit in accordance with the direction of rotation of said commutator, a second commutator driven by said motor and forming part of said energizing circuit, said first and second commutators being electrically connected, whereby upon the operation of said commutator driving I 7 means said motor will be energized by sequential impulses to a speed and direction of rotation which are functions of the speed and direction of rotation of said driving means, and means operable by centrifugal force generated upon the rotation of said driving means in excess of a predetermined speed to provide continuous excitation of said motor.

3. A motor control system comprising an energizing circuit for said motor, said circuit comprising a pair of conductors providing alternative conductive paths, a control means rotatable in opposite directions and controlling th sense of the application of energy through said circuit to said motor in accordance with its direction of rotation, a pair of switching means, one of said switching means being driven by said control means and the other being driven by said motor, each of said switching means establishing contact sequentially between said conductors and the remainder of said circuit a plurality of times for each rotation of said control means, and means operable in response to rotation of said motor in excess of a predetermined speed to cross connect said conductors, thus providing said motor with continuous excitation.

4. A motor control system comprising an energizing circuit for said motor, said circuit comprising a pair of conductors providing alternative conductive paths, a'control means rotatable in opposite directions and controlling the sense of the application of energy through said circuit to said motor in accordance with its direction of rotation, and a pair of switching means one of said switching means being driven by said control means and the other being driven by said motor, each of said switching means establishing contact sequentially between said conductors and the remainder of said circuit a plurality of times for each rotation of said control means.

5. A motor control system comprising an energizing circuit for said motor, said circuit comprising a pair of conductors providing alternative conductive paths, a control means, and a pair of commutators, each of said commutators having at least four segments, one of said commutators being driven by said control means and the other beingdriven by said motor, eachof said switching means establishing contact sequentially between said conductors and the remainder of said circuit.

6. A motor control system comprising an energizing circuit for said motor, said circuit comprising a plurality of conductors providing alternative conductive paths, a single conductor forming part of said circuit, a switching means operative to establish contact sequentially between said conductors and said single conductor, a second switching means driven by said motor, an exciting coil for said motor forming a part of said energizing circuit, the direction of current flow through said coil determining the direction of rotation of said motor, said coil having a pair of terminals in conductive relation to said second switching means and a center tap conductively related to said motor, conductive means providing a branch of said circuit connected between said terminals, said branch hav ing a terminal in conductive relation to said second switching means, said second switching means being operable to establish contact sequentially between the conductors of said plurality of conductors and each of the terminals of said coil and said branch, said terminals being so arranged that upon contact being established between one of said plurality oi conductors, said single conductor and one of the terminals of said coil, said second switching means will be so driven as to break the contact with said coil terminal and establish contact between said one of said Diurality of conductors and the terminal oi said branch, a warning device and means responsive to current flow through said branch by way of any of said terminals to maintain said warningdevice in a non-operating position.

'7. A motor control system comprising an energizing circuit for said motor, a rotatable driving means, a rotatable switch forming a part of said circuit and being driven by said driving means, said switch normally being open and being closed in either of two directions by the operation of said driving means in accordance with the direc-' tion of rotation thereof, thereby controlling the sense of the application of exciting energy to said motor in accordance with the direction or rotation of said driving means, a commutator driven in accordance with the rotation of said driving means, a second commutator driven by said motor, each of said commutators comprising a plurality of conductive segments, means connecting the segments of each of said commutators in alternation into a plurality of conducting units, means conductively connecting the corresponding units of said commutators, said commutators forming part of said energizing circuit, and means operable by centrifugal force generated by rotation of said second commutator in excess of a predetermined speed to conductively connect all of the conductive units Of said commutators.

8. In a motor control system comprising an energizing circuit for said motor, a rotatable driving means, a rotatable switch forming a part of said circuit and being driven by said driving means, said switch normally being open and being closed by said driving means in accordance with the direction of rotation thereof, said switch thereby controlling the sense of the application of exciting energy to said motor in accordance with the direction of rotation of said driving means, a commutator driven in accordance with the rotation of said driving means, a second commutator driven by said motor, each of said commutators comprising a plurality of conductive segments, means combining alternate segments of each of said commutators to form a plurality of conductive units and means conductively connecting the corresponding units of said commutators, said commutators forming part of said energizing circuit.

9. In a motor control system comprising an energizing circuit for said motor, a rotatable driving means, a commutator driven in accordance with the rotation of said drivingmeans, a second commutator driven by said motor, each of said commutators comprising a plurality of conductive segments, means combining alternate segments of each of said commutators to form a plurality of conductive units and means conductively connecting the corresponding units of said commutators, said commutators forming part of said energizing circuit.

10. In a motor control system comprising an energizing circuit for said motor, said circuit comprising a plurality of conductors providing alternative conductive paths, a single conductor .forming part of said circuit, a switching means operative to establish contact sequentially between said conductors and said single conductor, a second switching means driven by said motor, and an exciting coil for said motor forming a part of said. energizing circuit, the direction of current flow through said coil determining the direction or rotation oi said motor, said coil having a pair of terminals in conductive relation to said second switching means and a center tap conductively related to said motor: the combination with said system of conductive means providing a branch of said circuit connected between said terminals, a third terminal connected to a central portion or said branch and in conductive relation to said second switching means, said branch including resistive means impeding the Ilcw of current therethrough between said terminals, said switching means being operable to establish contact sequentially between the conductors oi said plurality of conductors and each of said terminals, a warning device and means responsive to current flow through said branch by way of any of said terminals to maintain said warning device in a non-operating position.

11. The'combination as set forth in claimlO, the last named means comprising inductive elements connected to respond to current iiow in said branch.

Certificate of Correction Patent No. 2,490,485

12. The combination as set forth in claim 10, the last named means comprising a pair circlenoids connected in parallel between points on said branch intermediate respective pairs of said terminals and a point in said circuit, such that current flowing through said'solenoids does not flow through said motor.

JOSEPH 'I. McNANEY.

I REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 720,729 McDonnell Feb. 17, 1903 1,578,189 Hewlett et a1. Mar. 9, 1926 1,611,192 Ewald Jan. 11, 1927 1,781,762 Murphy Nov. 18, 1930 1,788,793 Hall Jan. 13,1931 1,985,007 Ashworth Dec. 18, 1934 2,085,442 Newell June 29, 1937 3,821,599 O'Brien June 15, 1943 February 7, 1950 JOSEPH T. MONANEY It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 7,

lines

48 and 49, for the words switching means" read eommutators; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and'sealed this 30th day of May, A. D. 1950.

[sun] 4 THOMAS F. MURPHY,

Assistant Oomrnim'oner of Patents.