US2697803A - Relay system - Google Patents

Description

Dec. 21, 1954 E. M. EADIE, JR

RELAY SYSTEM Filed Aug. 21, 1951 2 sneaks-sheet 1 ro /10 vous 4.a. 9o\ @7,1 C1)/67 l 55 5,

EDWARD M. EAD/E, JR

IN V EN TOR.

ATTOI? YS E. M. EADIE, JR

Dec. 21, 1954 RELAY SYSTEM 2 Sheets-Sheet 2 Filed Aug. 21, 1951 r1.1. .I l

EDWARD M. EAD/3.12,

INVENTOR Arron ys RELAY SYSTEM Edward M. Eadie, Jr., Westfield, N. J., assignor to Weston Electrical Instrument Corporation, Newark, N. J., a corporation of New Jersey Application August 21, 1951, Serial No. 242,859

Claims. (Cl. S17- 124) This invention relates to relay systems and more particularly to a sensitive relay system that includes a senlight controller of the photocell-actuated type but the broad scope of the invention is not to be limited thereto United States Patent O Cil as other appropriate uses of my system will readily be apparent to those skilled in this art.

In a photoelectrc light controller of the type to which this invention relates, the varying outdoor illumination results in a varying current output of a photocell. Such photocell output controls the deflection of the movable contact arm of a sensitive instrument type relay provided with magnetic contacts. Closure of such relay contacts completes a circuit to an electric motor of the clock type whereby there is set into operation a mechanism that results in the closure or opening of heavy contacts for the control of the electric lights. Suitable arrangements are provided to prevent improper operation of the system and to bring the system to the at-rest position whereby no poier is consumed until the next operation cycle is initiate An object of this invention is the provision of a control device including an instrument relay, magnetic elements for insuring a positive and reliable closure of the instrument contacts, and motor operated mechanism controlled by the instrument contacts for thereafter opening the contacts and controlling a switch or switches in the load circuit.

An object of this invention is the provision of a control device of the type stated in which a single instrument relay is employed to control both the on and off operation of the load switch and in which the motor operated mechanism includes elements for presetting the relay and for determining the operating sequence of the load switch.

An object of this invention is the provision of a control device including an instrument having a contact arm movable between two stationary contacts to close separate circuits therewith, magnetic elements for insuring a firm closure of the instrument contacts, a motor controlled by the closure of one or the other sets of instrument contacts, rotatable elements for actuation of a switch to the open or closed position and elements for opening the motor circuit after a predetermined time, and elements for resetting the instrument contacts before the opening of the motor circuit. y

An object of this invention is the provision of a sensitive relay system for the regulation of relatively heavy current loads said system being of simple construction, positive operation and housed in a water-tight housing of the plug-in type.

These and other objects and advantages will become apparent from the following description when taken with the accompanying drawings. It is to be understood the draw- `ings are for purposes of description and are not to be construed as defining the scope or limits of the invention, reference being had for the latter purpose to the appended claims.

' In the drawings wherein like reference characters denote like parts in the several views:

ice

Figure 1 is an isometric view of a control device made in accordance with this invention;

Figure 2 is a circuit diagram of the control device;

Figure 3 is a side elevation of the device shown in Figure l;

Figure 4 is a front elevation of the device disposed within a circular housing of the outdoor, plug-in type; and

Figure 5 is a side elevation of Figure 4 with certain parts shown in section for the better illustration of the device.

Reference is now made to Figure l showing the assembly ot' the individual components upon a base 10 of insulating material. The sensitive relay 11 is of the permanent magnet, movable coil type that includes the movable coil 12 carrying an arm 13 movable over a graduated scale 14. The arm 13 carries a rider 15 of soft-iron that is arranged to contact one or the other of the stationary contacts 16, 17, that are supported in iixed position by suitable means. The contacts 16, 17 are small permanent-magnets. As is well known, rotation of the movable coil 12 will bring the rider 15 into the iield of influence of one or the other of the stationary contacts. When this happens the rider is magnetically attracted to such contact resulting in a positive, firm contact closure. In magnetic contact relays ot' this type the energy developed by the instrument movable coil is, generally, not sutlicient to separate the rider from the magnetic contact and, therefore, some mechanical contact-resetting means must be provided. Also, in an on-ott controller, it is desirable to arrange the resetting mechanism such that the movable arm of the relay is I'ree to contact only that stationary contact which will initiate the next desired operating cycle. For example, in a photoelectric light controller, it the relay arm 13 engages the stationary contact 16 the device will operate to cause a closure of a power switch to turn on the lights (indoor or outdoor). When that portion ot' the operating cycle is completed, the mechanical reset mechanism will separate the rider 15 from the contact 16 and will condition the relay for the next operating cycle, that is, closure of the contacts 15 and 17. Upon such latter contact closure the device will operate to open the power switch to turn the lights ol after which the resetting mechanism will separate the rider 15 from the contact 17 and condition the relay t'or the next operating cycle, namely, a subsequent closure of the contacts 15 and 16. A complete operating cycle of the device will be described in detail hereinbelow. It is here pointed out that the movable coil 12 of the relay is electrically connected to the terminals 20, 21, the stationary, magnetic contacts 16 and 17 are connected to the terminals 22, 23, respectively, and the movable arm 13 is connected to the terminal 24.

The sensitive relay 11 is mounted on the front of the base 10 by the four screws 25. 1t may here be stated the cover of the relay is made of a transparent plastic affording a ready view of the internal parts, particularly `the arm 13, contacts 16 and 17 and the scale 14. At-

tached to one side of the relay cover is a bracket 27 supporting the rod 28 that has one end extending through a clearance hole in the plate 29. A freely-rotatable sleeve 30 is disposed between the rear arm of the bracket 27 and the front face of the plate 29, and the rod 28 has an enlarged head contacting the rear of the plate 29, from which it will be apparent the rod 28 forms an axis about which the plate 29 can be rotated. A hollow rod 31 is rigidly secured to the plate 29. This rod accommodates the end of a smaller, solid rod 32 having a right angle bend therein, said rod 32 passing into the relay 11 through a bushing 33 secured to the side of the relay` cover, substantially as shown. The inner end of the rod 32, that is, the end disposed within the relay, lies in a plane above that in which the relay arm 13 rotates and such inner end carries a bushing 34 to which a thin, curved wire 35 is attached, as by soldering or welding. This wire 35 has a central portion passing over the relay arm and the ends of the wire are otlset downwardly (toward the base of the relay). Ceramic bushings 36, 37 are carried, individually, by the ends of the flexible wire 35. The spacing between the bushings 36, 37 is such that when the reset rod 32 is in the position shown the bushing 36 prevents the relay arm 13 from contacting the stationary contact 16 while the bushing 37 lies out of the path of travel of the arm inthe direction of the 'stationary "Contact 17. Assuming now that the relay arm 13 has contacted the stationary contact 17, it will be apparent those contacts will b'e separated when thereset ar'm 32 is moved further into the relay housing. Such *movement of the reset arm will cause the ceramic Ebushing`3f7 to move the arm I13 toward the 'center "of lthe 'scale 14 and `outo'f `the tield of iniluence of the magnetic contact 17. In so resetting the contacts 15and 517 the other ceramic bushing is moved jto a `point outlofithe `path of tra-vel of `-the relayarrn when the arm moves in the direction Aof Lthe other stationary contact 16. vrCo`nse`quently, iin the Aoperation vof the `resetting mechanism, the relay 11 is conditioned such that the `movable arm can 'only engage the proper stationary Vcontact to 'initiate the next desired'operating cyclefof the device as a whole. Since the ipla'te 29 is pivotally movable 'about the axis formed by therodZS, it is apparent that a counter- -clockwise rotationof the plate will cause the reset arm to move `further-intofthe relay housing, bringing about the condition jus't described. A subsequent clockwise 'rota- 4tion ot the `p`late29 `will frestore the reset arm, and the ceramicibushings 36,-37 to the position shown in -Figure l.

Rocking 1movement of the plate 29 is controlled by a bracket *'40 that is Vpivotally 4secured -to the base 10 by meansof ailarge headed screw 41. The bracket 40 has Yau offset, `upperportion to which a pair of conventional springclips 42 are attached, as by the rivets 43, said spring `clips serving-as `supports for a mercury switch 44 that is lconnectedlbyitheexibleleads 45 to terminals 46 secured to the base 10'by screws 46@ Theiterminals 47 are likewise secured to lthe base 10 and serve as a `means for connecting thefmercury switch into an electrical circuit. It willlbe noted that the bracket 40 includes an extended, tapered end 50 that-extends under the pivotedplate 29. Arod vv51passesthroughanopening in the tapered end 50 `such rodbeing securedfrigidly to theend as by soldering. lOne'endof the rod51 passesthrough aslot52 in -the plate 29 whilethe"other'endpasses through an openinglSltin theibase 10 and occupies a positionbetween the loffset ends of aswitch` comprising theblades 55, '56. The switchblades 55, 56 are'rnounted 'onthe rear of the base -liaswillibe explained in detail withreference to Figure 3, below. `When the bracket40 is'rotated in a clock- 4wisedirection, yabout its mounting screw 41,the rod 51 will impartac`ounterclockwise rotation to the pivoted f plate A"29 thereby moving-thereset rod 32further into the 'housing of 'therelay -`1'1 and separating the relay contacts 15,17. Asubsequent counter-clockwise rotation ofthe bracket Jt0 'willreturn the plate 29aud the reset rod to the Viposition'showtn infthe'drawing. Thus, the opening I and vclosing of: the mercury switch is mechanicallytied-in v-with -the'resettingfot therelay contacts-in asimple and .positive manner.

vflher'ocking movement of the bracket40, carrying the mercury switch,` is controlled byt rotation ofthe relatively 2 thick disc-G that is eccentrically, but-rigidly, attached to the shaft llextending from thegear box v62 of a small, clock-type motor F63. The disc extends `through a clearance openingf64 in the `base y10 and its diameter is `such that the idiscrjust fits lbetween the downwardly-depending arms65 that are.an integral part of the bracket 40. Since the 4bracket 40iis.pivoted atta point spaced from the `disc 60, specifically, by the screw 41, rotation of the disc will'impart a rocking movementto the bracket. Consequently, by de-energizing the motor at the proper points in the `operating-cycle, the bracket 40 will occupy two positions. One'such position is shown inFigure l; the mercury switch contacts being closed in this position. The other `position issuch that the mercury switch is tilted approximately 30 degrees, in a counter-clockwise direction from the Figure l showing, and in which position the -mercury switch contacts are open-circuited.

De-energization of the clock motor is accomplished by the switch bladesfSS, S6 that are mounted on the back of the base 10, as `shown more clearly in the side elevation view, Figure 3. The blades are electrically insulated from each other and the mounting bracket by conventional spacers 71, the` entire complement of blades and spacers being held together by two4 screws 72 (only one such screw being visible in Figure3 )l that pass through `insulator tubes disposed in alined'openings-in thebladesI and spacers, as is well known in Jthis art. Two screws 73 (only one such screwbeing visible in 'Figure 3) secure the angle Y`brac'ket"70" to" the Abase 4'10 and position the two blades Vblade carries a contact button 55' and 56 and the blades are so assembled that the Contact buttons normally engage each other, that is, the electrical circuit between the two blades is closed when the rod 51 occupies a position intermediate of the oiset ends of the blades. Since the rod 51 moves with the bracket 40 it `will be apparent the rod will flex the blade 56 when the bracket 40 rotates a predetermined amount in the counter-clockwise direction thereby separating the contact buttons 55', 56. Likewise, upon a predetermined amount of clockwise rotation of the bracket 40 the rod 51 will flex the blade 55 and so also separate the contact buttons 55', 56'. By connecting the blades 55, 56 between the clock motor and the source of power it will be apparent the motor will be de-energized when the rod 51 causes a separation of the contact buttons 55', 56. Although the motor shaft 61 rotates in only one direction the eccentrically-mounted disc 60 imparts a rocking movement to the mercury-switch-carrying Ibracket 40 and the limits of such rocking motion are established by the opening of the contact buttons 55', 56.

A photoelectric cell 7S, preferably of the drydisc, selfgenerating type is disposed in front of the sensitive frelay being supported from the base 10 by a suitable bracket 76. The photoelectric cell is connected to the Amovable coil of the relay by leads soldered to the relay terminals 20, 21 whereby lthe relay arm 13, or pointer, takes up a position, lrelative to the scale 14, depending upon the amount oflight striking the photocell surface. As shown infFigure 3, the photoelectric cell can be tilted to a limited extentin order to respond to light coming predominantly from a desired direction. Any suitable mounting maybe emlployed for theadjustable support of the photoelectric cel With further reference Vto Figure 3, it will be notedthe base 10, upon which the components of my controlidevice are mounted,.is supportedon a metal sub-baseby the posts 81 that'are attached to the sub-base as by peening over the postends. The `mounting -screws 82rpass through holes 83 in the base ll() '(see Figure l) andare threaded intothe posts. Such mounting of thebase 10fon `a sub baseis desirable when the entirecontrol apparatus is encased in `anoutdoor housing-of the plug in-type,.as the entire apparatus can-be removedfrom the frontofthe housing by unscrewing the mounting screws 82. The housing will be further described hereinbelow with referencetoFigures 4'and 5.

`Reference is 4now made ytofFigure 2 which Vis a wiring diagram of the lightcontroller and includes a diagrammatic representation of the various components and ltheir functions. The photocell 75.is connected directlyltothe movable coil 12 ot the sensitive relay.11'by1theleads 85. Conventional hair springs normally bias thefmovable coil so that `the `arm 13 movesto apoint beyond the stationary contact 16 `when no currentLtlows'through the movable coil. In other words, the movable-coil and its arm `13,rotate.in a clockwise direction with increasing currentfow through the coil. Thoseskilled inthis art will know that `the photocell-relaycombinationcan be adjusted so that contactclosure betweentheri'der 1S and either of themagnetic contacts v16, `17 will 'take place when the .light intensity on the ,photocellssurface drops or increases to predetermined-values. As 4.shown in the drawing the `apparatus is in the at,rest,position and the mercury switch y44 is inzthe closedcircuit position. Consequently, thelamps 86, whichmayberoom lights, street lightsortetc., are on'being Aenergizedrby the power `source `connected to the terminals :87. The terminals87 are carried bythe base.10.of the. controller, as shown in Figure l. As explained aboveywhenrthe mercury switch is inzthe closed Vposition the .'resetarm 32 of the relayoccupies aposition whereby the,.ceramic bushing 36 prevents closureof the rider 15 :with the contact 16. Thus, a decrease inthe amount of light` striking the photocell surface merely results .in the relay;,arm 13 striking the bushing 36 but the controllerremains in the at rest,po'sition. As .the light .intensityincreases the movable coil.12 andtarm 13 rotatein agclockwise direction `and closure of the relay contacts ,f 15and,217 occurs when .the light .intensity-reaches apredetermined magnitude. v.Closure of the contacts `15, t17 .enet'gzes the clock motor 63, the circuit comprising the wires90, 91, 92, contacts .151,.17, wires 93,.,94,95the motor 63, and wires 96, v97. Rotation `of, the. motorfshaftwl results in a corresponding rotation of the disc 60. Referring now to Figure 1, rotation stated operations occur in the following order:

of the disc 60 imparts a clockwise rotation to the bracket 40 whereby the mercury switch 44 tilts toward the open circuit position, the rod 51 moves away from the lower switch blade 56 permitting closure of the contact buttons 55', 56', and the pivoted plate 29 moves in a counter-clockwise direction. The various cooperating parts are so designed thatV the `the contact buttons 55', 56 have closed, the motor continues to run even though the relay contacts are opened. When the limit of travel of the reset rod is reached the ceramic bushing 37 will prevent further contact between the rider and the contact 17, and the other bushing 36 will be removed from the path of the pointer travel toward the contact 16.

3. The mercury switch tilts to the open circuit position and the lamps 86 go out.

4. The rod 51 iiexes the upper contact blade 55 thereby separating the contact buttons 55', 56. Since the relay contacts 15, 17 have already been opened by the reset rod 32, separation of the contact buttons 55', 56 deenergizes the clock motor.

It is apparent that upon completion of the above cycle of operation all components are at rest and energy is not consumed from the 110 volt power source. the light striking the photocell surfaces decreases, as at dusk, the relay arm will move toward the stationary contact 16, eventually closing therewith when the light intensity drops to the predetermined value. Closure of the relay contacts 15, 16 energizes the clock motor, the circuit comprising the wires 90, 91, 92, contacts 15, 16,

wires 98, 99, 95, motor 63, and wires 96, 97. RotationA of the disc 60 now imparts a counter-clockwise movement to the bracket 40 whereby the above-listed operations again take place in the order stated. Now, however, the mercury switch 44 tilts to the closed circuit position closing the power circuit to the lamps 86, the reset rod 32 separates the relay contacts 15, 16 and conditions the relay for a subsequent closure of the contacts 15, 17, and the rod 51 eventually exes the contact blade 56 to open the motor-control contact buttons 55', 56.

By mechanically linking together the movement of the mercury switch, the resetting of the sensitive relay contacts, and the operation of the motor-control contact buttons, proper operation of the controller is assured.

Once the relay contacts close the motor is energized and a re-opening of the relay contacts takes place only after the contact buttons 55', 56 are closed. Consequently, the relay contacts are opened, under a condition of no load, thereby promoting long contact life. Since the opening of the contact buttons 55', 56 is controlled by the rod 51 attached to the rocking bracket 40 it is apparent that the extremity of oscillation of the bracket is determined by the positioning of the contact blades 55, 56 relative to the rod 51. These blades are so positioned that the motor is de-energized at a point just prior to the extreme limit of rotation, in either direction, imparted to the bracket 40 by the disc 60. As is well known, the mercury switch opens and closes in response to a relatively small `angular tilting thereof. In the design of the apparatus the bracket 40 is subject to an angular rotation that exceeds the necessary angular tilting of the mercury switch thereby providing an ample safety factory to assure on-of operation of the external load within the two operating cycles described above. Inasmuch as the movable parts are subject to limited movement at relatively slow velocity, the factor of wear is insignificant resulting in a device having a long operating life with minimum maintenance.

Photoelectric light controllers are used quite extensively to control street lights and it is desirable to mount the controller on the light stanchion or pole. To facilitate such mounting of the controller I place the entire device within a glass front, plug-in housing of the type commonly employed to house watthour meters, as shown in Figures 4 and 5. The housing comprises a base 90 carrying the blade-type terminals 91, each terminal being insulated from the base by a suitable insulator member 92. The outer ends of the terminals are adapted to plug into cooperating spring-type contacts carried by a socket member that is secured in xed position, said spring type contacts being connected to appropriate electrical circuits. The device carried by the base is adapted for mechanical and electrical connection and dis-connection with the socket member through the cooperating terminals carried by the base 90 and the spring contacts carried by the socket member.

A glass cover 93 is attached to the base 90 by a ring member 94, said ring member being of the type that causes the base 95 of the glasscover, to compress the gasket 96 against the lip 97, of the base, to provide a water tight joint. As already described, the components of the light controller are mounted upon an insulator base 10 that is, in turn, supported on a sub-base 80 by the posts 81 and screws 82. This sub-base 80 is supported in spaced relation relative to the base 90, of the housing, by a set of studs 99 and 100, the latter being threaded to accommodate the screw 101.

All necessary electrical connections between the components of the controller are made to the terminals 87 and 46, carried by the base 10. vElectrical connections between the terminals 87, 46 and the blade-type terminals 91, carried by the housing base 90, are made by suitable, ilexible cables 102 passing over the top and bottom edges of the base 10, said cables being provided with solder terminals for this purpose. Thus, the plugging-in of the terminals 91 into the cooperating spring contacts ofthe socket member places the controllerin operating condition. The glass cover exposes the entire device to ready view. In the event of failure of any component, or damage thereto, a new controller can be substituted, in situ. The glass cover of the housing is removable from the base 90 upon rotating the cover and ring 94 approximately 20 degrees. The connection cables are disconnected from the main base 10 and the entire assembly removed by unscrewing the mounting screws 82 by .which such base is attached to the supporting posts 81.

Having now described my invention in detail in accordance with the patent statutes, certain changes and modifications in the arrangement of the parts will be apparent to those skilled in this art. Such changes and modifications may be made without departing from the scope and spirit of the invention as set forth in the following claims.

I claim:

1. Control apparatus comprising a sensitive relay having a pivotally-mounted movable coil carrying a contact arm and stationary contacts disposed on opposite sides of the contact arm, said contact arm engaging one or the other of the stationary contacts in accordance with the magnitude of the current owing in the movable coil; a reset member movable in one direction to move the relay contact arm out of engagement with one stationary contact and movable in the reverse direction to move the contact arm out of engagement with the other stationary contact; a uni-directional motor having a shaft; circuit elements connecting the motor to a source of electrical energy upon closure of the relay contact arm with either of the stationary contacts; a disc eccentrically secured to the shaft; a pivotally-mounted bracket having a pair of spaced arms extending along diametrically opposed sides of the disc, said arms being contacted by the peripheral surface of the disc, upon eccentric rotation of the latter, to thereby impart oscillatory rotation to the bracket; a mercury switch carried by the bracket, said switch being closed upon rotation of the bracket in one direction and opened upon bracket rotation in the other direction; mechanical coupling means between the bracket and reset member to move the reset member in one direction or the other in correspondence with the rotary movement of the bracket; a normally-closed holding switch comprising contacts carried by a pair of flexibleblades, one blade being connected to the relay contact arm and the other being connected to both said stationary contacts; and means carried by the bracket and opening the holding switch contacts at points just prior to the limits of the rotary movement of the bracket.

2. The invention as recited in claim 1, wherein the 7 said mechanical coupling comprises a piyotallyfrnounted plate, rotatable in a' plane substantially parallel to, the Plane. of movement of the reset member, saitl plate iucluding a slot and carrying a. hollow roti, an oltset end on the reset member, said end being loosely disposer,l in the said. hollow roti, and. a pin secured to the braeltet and extending through the said slot- 3,.A The invention as recited in elairn 2, wherein the .said pin also. constitutes the means opening the said holding switch contacts.

4- A photoeleetrio controller comprising a mounting plate; a sensitive relay having a pivtally-mountel mpvable Coil carrying a Contact am; and stationary oritlacts disposed on opposite sides of the. eontact arm, said contact arm engaging one or the other oi the stationary contacts in accordance with the magnitude of the our ,nt tlowing in the movable coil; a photoelectric gell by the mounting plate .and connected to the relay rnov v able coil; a pusher rod extending externally ot the relay housing and having an offset outer eno; a. pair oi ilentible members secured, to the inner end of pusher rod, said members lying in the path of travel of the relay contact arm and being spaced apart a distance less than the spacing between the. stationary relay contacts; a .coubling plate having a slot anti. carrying a tube within which is disposed -the offset end of the pusher arm, said plate being pivotally secured to the exterior of the relay housing and rotatable in a plane substantially parallel to the plane of movement of the. relay contact arm; a uni-directional motor carrierl by .the mounting Plate and having a shaft; circuit elements connecting the motor to .a source of electrical energy upon closure of the relay contact arm with either of. the stationary contacts; a oise eceentrieally secured .to the motor shaft; a bracket oivotally secured to the mounting plate .and rotatable in. the Plane, of said: coupling Plate, said bracket having a noir of spaoeo arms.; entertains along and, eoiacent to fil rnetrioall opposed cities o the elise such that, the are .acted by the Peripheral surface ci the disc upon eccentric rotation of the latter to thereby irnoart oscillatory rotation to the bracket; a mercury switch carried by the bracltet, saicl switch being opened and closed reeoeetiyely upon rotation of. the brochet in one or the other direction; a nin carried by the bracltet and encoding through the slot in tbe. salti coupling plate; a noir of; ilenible blades carried by the mounting plate and having ends soacleo on 'opposite sioles of the said pin; normally-closed cooperating electrial c titacts arifid by the blades; anti legos connecting one. blade to the relay contact antl the other blade. to both stationary contacts of the relai/, the solo Pin ileXing one or the other of the spaced 'ends of the iiexible blades to senarate the saitl cooperating contacts when the bracltet appxjaclies its limit 9 oscillatory mvement.

5 The invention as recitetl in claim 4, wherein the ,stationary relay contacts are Permanent magnets and the relay contact arm, carries a rider of magnetic material tor engagement with the stationary eontsetsi References Cited in the fille 0f this gatent UNITED STATES PATENTS

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