US2467454A

US2467454A - Electrically actuated remotecontrol apparatus

Info

Publication number: US2467454A
Application number: US664777A
Authority: US
Inventors: Arnot Alfred Reginald Erwin
Original assignee: Rotax Ltd
Current assignee: Lucas Support Services Ltd
Priority date: 1945-03-05
Filing date: 1946-04-25
Publication date: 1949-04-19
Anticipated expiration: 1966-04-19

Description

April 1949. A. R. E. ARNOT 2,467,454

ELEGTRICALLY ACTUATED REMOTE-CONTROL APPARATUS Filed April 25, 1945 2 Sheefs-Shet 1 April 19, 1949. ARNQT ELECTRICALLY ACTUATED REMOTE-CONTROL APPARATUS Filed April 25, 1946 2 Sheets-Sheet 2 Patented Apr. 19, 1949 ELECTRICALLY ACTUATED REMOTE- CONTROL. APPARATUS Alfred Reginald Erwin Arnot, London, England, assignor to Rotax Limited, London, England Application April 25, 1946, Serial No. 664,777 In Great Britain March 5, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires March 5, 1965 3 Claims.

This invention has for its object to provide improved electrically actuated remote-control apparatus of the kind in which a reversible electric motor is controlled by a pair of potentiometers, one of which is manually operable and is situated at a distant position, and the other of which is operable by the motor.

In the accompanying sheets of explanatory diagrams:

Figure 1 illustrates one form of electrically actuated remote control apparatus in accordance with the invention.

Figure 2 illustrates a modified form of the invention,

Figures 3 to 8 illustrate modified details.

In carrying the invention into effect as illustrated in Figure 1, I employ a reversible electric motor a which is required to impart to a mechanism movements in response to signals received from a distant station, and I arrange in association with this motor a pair of electro-magnetic contactors 0. Each of these contactors comprises a magnet winding d, an armature e carrying three contacts f, f f three complementary fixed contacts g, g g and a resistance :1 in series with the winding, the arrangement of the contacts being such that an initial movement of the armature closes the contacts g and opens the contacts f 9 for bringing the motor a into action, and further movement of the armature also closes the other contacts f g for putting out of action means whereby the rate of motion of the motor is retarded. Such means may consist of a normally-operative brake adapted to be released by an electro-magnet, the winding of the latter being indicated by k. Alternatively the motorretarding means may consist of a resistance which can be interposed in any suitable part of the motor circuit. One of the contactors serves to set the motor a in motion in one direction, and the other to set the motor in motion in the opposite direction. To enable this to be effected the motor a, may be series wound and provided with a pair of oppositely wound field windings m, in which case one of the contactors 0 controls the circuit through one of the field windings, and the other controls the circuit through the other field winding.

In association with the two contactors c are arranged a pair of normally-open electro-magnetic relays n of the polarized or moving-coil type. Each of these relays comprises a fixed contact o situated between a pair of movable contacts p, and an armature (not shown) for actuating the movable contacts, the direction of motion of the armature being dependent on the direction of current through a winding q forming part of the relay. One of the relays n (which is herein termed the first relay) serves to control the supply of current directly to the winding (1 of either of the two contactors c, and not through the associated series resistance :1 above mentioned. Thus, when the armature of the first relay n is moved in one direction from its normal position it causes the circuit of one of the contactor windings d to be closed independently of the corresponding resistance a, and when moved in the opposite direction it causes the circuit of the other contactor winding, to be closed in a similar manner. The other of the relays n (which is herein termed the second relay) controls the supply of current to one or the other or the contactor windings d through the corresponding series resistance y. In this case, the contactor 0 brought into action by the second relay n closes only the corresponding contacts J, g and leaves the above mentioned motor-retarding means in action. Preferably and as shown the second relay n is provided with another winding 1 which when energised assists the corresponding winding q.

Current is supplied to the relays n, contactors c and motor a from a common supply system 3 under the control of a pair of potentiometers t of any convenient and appropriate form, one of the potentiometers being operable in response to movement of the motor a, and the other being responsive to manual operation and situated at a distant position.

In the example illustrated by Figure 1 each potentiometer 22 comprises an annular main resistance it having its ends connected to the supply system 3, and having a contact '0 which is movable around the main resistance by a spindle w, the contact being connected to the circuit containing the winding q of the first relay n. Also the ends of the main resistance u are connected to the ends of a relatively short subsidiary resistance a: of segmental form, and the spindle w which carries the contact 1) also carries two sets of equi-spaced and alternately arranged contacts y, ,2 which can be moved over the subsidiary resistance. It will be understood that the contacts 22, y, a are secured to and movable simultaneously by the spindle w. The two sets of contacts y, a are respectively connected to a pair of slip rings v2, 3 on the spindle w, and the arrangement in such that not less than one of these contacts and not more than two can be in contact with the subsidiary resistance u at any time, The slip ring 2 is connected to the circuit con-- taming one of the windings q of the second relay n, and the other slip ring 3 is connected to the circuit containing the other winding r of that relay, the arrangement being such that when both windings are energised they assist each other. A potentiometer as above described forms the subject matter of my co-pending application Serial No. 664,776, now Patent No. 2,442,228, patented May 25, 1948.

The arrangement of the potentiometers t, relays n and contactors c is such, that when the spindle w of the distant potentiometer is moved through an angular distance corresponding to the movement required to be performed by the motor a, a state of unbalance is created between the two potentiometers. Consequently, current flows through a circuit containing a part of the main resistance u, contact 1), and spindle w, of the distant potentiometer, the winding q of the first relay n, and the spindle in, contact 1), and a part of the main resistance a of the other potentiometer. Also current flows through a circuit containing a part of the subsidiary resistance :r, the adjacent contact or contacts y, 2, and one or each of the

slip rings

2, 3 of the distant potentiometer, one or each of the windings q, r of the second relay n, and one or each of the

slip rings

2, 3, one or each of the contacts y, z, and a part of the subsidiary resistance :c, of the other potentiometer. Which of the relays is thereby brought into action by the current flow depends on the extent of the unbalance created between the two potentiometers i. If a large angular movement is imparted to the spindle w of the distant potentiometer, a relatively heavy current flows, and the first relay 11. comes into action causing the motor-retarding means above mentioned to be put out of action and the motor a to be rotated at a relatively high speed in the appropriate direction. When a stat-e of balance between the potentiometers t is approached, the current in the first relay it becomes insuii'icient to keep this relay in action. The second relay n then causes current to be supplied to the operative contactor c through the associated resistance 9, but this current is insufiicient to keep the contacts F, g of this contactor closed. The motor-retarding means thereupon comes into action, causing the motor a and the spindle w of the associated potentiometer t to be slowed down. When a state of balance is finally reached, the circuits are re-opened and the system comes to rest. If, on the other hand, a small angular movement is initially imparted to the spindle w of the distant potentiometer, a relatively light current flows, and the second relay it comes into action, causing the motor a to be rotated at a relatively low speed with the retarding means in action, and when a state of balance is reached the circuits are re-opened for bringing the system to rest.

In the modification illustrated by Figure 2, I dispense with the resistances 7' and contacts f 9 and arrange in the circuit of the motor a a vibratory interrupter for retarding the rate of motion of the motor when the first relay n ceases to be eiTective, the interrupter being operable by an electromagnet having its winding 6 connected across the motor armature. When the first relay n is in action the interrupter 5 is short circuited by a pair of contacts 1, 8, which are separable by an electromagnet having its winding Si connected at opposite ends to the contacts o of the two relays n, the arrangement being such that this winding is energised to separate the associated contacts only when the first relay ceases to function and the second relay is in action. The interrupter 5 then serves by intermittently breaking the motor circuit to retard the rate of motion of the motor a which, when a state of balance is reached between the potentiometers 75, may be brought to rest by an electromagnetically operable brake having its winding it in the motor circuit. In other respects the example illustrated by Figure 2 is essentially similar to that illustrated by Figure 1.

Instead of being arranged in and adapted to break the motor circuit as illustrated in Figure 2, the vibratory interrupter may be arranged in a variety of different positions. For example it may be connected across the ends of a resistance H in series with the motor a as shown in Figure 3.

Alternatively the interrupter 5 may be arranged to short circuit a part of the field winding 52 of the motor a as shown in Figure l, or it may be arranged to short circuit the armature of the motor a as shown in Figure 5.

In the example shown in Figure 6', the winding 5 of the interrupter electromagnet has combined with it an opposing winding is which is arranged in series with the interrupter 5, and the motor a.

Where the rate of rotation of the motor a is controlled by an electromagnetically operable friction brake, I may arrange the interrupter 5 to short circuit the brake magnet winding 10 as shown in Figure 7.

In the example shown in Figure 8 the interrupter 5 is provided with a compound winding 6, B and is arranged in series with a shunt brake winding Hi.

It will be understood that in all of the examples shown in Figures 3 to 8, the interrupter is adapted to be short circuited as in the example shown in Figure 2.

By this invention I am able to efiect the desired control of a motor from a distant position in a very simple and convenient manner. The invention is not, however, restricted to the examples above described, as subordinate details may be varied to suit different requirements.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. An electrically actuated remote-control apparatus of the kind specified, comprising in combination a reversible electric motor having retarding means responsive to electric current, a pair of potentiometers each having a main resistance and a subsidiary resistance, a pair of electro-magnetic contactors each adapted to control the supply of current to the motor, a pair of electro-magnetic relays adapted to be brought into action one after the other for controlling the supply of current to the contactors, and means for putting the motor-retarding means into and out of action under the control of the relays. one of the relays being responsive to current controlled by the main resistances of the potentiometers, and the other to current controlled by the subsidiary resistances of the potentiometers.

2. An electrically actuated remote-control apparatus as claimed in claim 1, in which the contactors are provided with contacts for controlling the supply of current to the motor-retarding means, and with windings arranged in series with resistances, one of the relays being adapted to control the supply of current directly to the contactor windings, and the other relay being adapted to control the supply of current to the contactor windings through the resistances.

3. An electrically actuated remote-control apparatus as claimed in claim 1 and having an electro-magnetically operable vibratory interrupter for retarding the rate of rotation of the motor when one of the relays is ineffective.

ALFRED REGINALD ERWIN ARNOT.

REFERENCES CITED Number 6 UNITED STATES PATENTS Name Date Tiffany Oct. 12, 1915 Harle June 4, 1918 Schneider Feb. 14, 1922 Wilhjelm May 4, 1937