US2178479A - Relay system - Google Patents

Description

Oct. 31, 1939.

A. H. LAMB RELAY SYSTEM Filed Dec. 7, 1936 2 Sheets-Sheet l 6 7 30a. as i w J05 Oct. 31, 1939. A. H. LAMB 2.178.479

RELAY SYSTEM Filed Dec. 7, 1936 2 Sheets-Sheet 2 Patented Oct. 31, 1939' UNITED STATES PATENT OFFICE Weston Electrical Instrument Gorporation,

Newark, N. 3., a corporation of New Jersey Application December 7, 11936, Serial No. 114,715

13 Claims.

This invention relates to relay systems and particularly to relay systems of the type which includes a sensitive measuring instrument for regulating the flow of relatively heavy currents in control and/or alarm circuits.

An object of this invention is to provide sensitlve relay systems of compact and simple construction that may be used to control relatively heavy current flow for the actuation of an alarm or control mechanism. An object is to provide a relay system of the type including an instrument relay having magnetic contacts and a lllO- tor-actuated mechanism for resetting the instrument contacts, the resetting mechanism beof simple design and mounted directly upon the power shaft of a miniature or 010 s motor. lore particularly, an object is to provide an exeedin ly compact physical construction for a sensitive control system including an instr merit a: relay having magnetic contacts, and. a clock type sell-starting synchronous motor for resetthe instrument relay, the relay and motor being partially overlapped upon a supporting base to position the contact arm of the relay within the path of movement of a push-er arm mounted directly upon the power or slow speed shaft of the cloclr type motor.

These and other objects and advantages of the invention will be apparent from the follow-- ing specification when taken with the accompanying drawings in which:

Fig. l is a front elevation of an embodiment of the invention, the casing which houses the relay or control system being broken away; i 35 Fig. 2 is a vertical section of the same as taken substantially on line 22 of Fig. l;

Fig. 3 is a side elevation of the same, as seen from the opposite side of Fig. 1 and with the casing removed; Fig. 4 is a wiring diagram of the apparatus shown in Figs. 1 to 3;

Fig. 5 is a wiring diagram of another embodimerit of the invention; and

Fig. 6 is a perspective view of a combined 4g switch and pusherarm unit such as shown in Figs. 1 to 3. I

In the drawings, the reference numeral l identlfles a base that may be mountedupon a panel, not shown, to carry theentlre control mechanism. A protective housing 2 fits loosely over the supporting base and has a window 3 through which the -moving parts of the control unit are visible.

The measuring instrument or relay includes a 55 permanent magnet (not shown), a pivoted coil 4 and a pointer 5 that carries a soft iron rider t for cooperation with relatively stationary magnetic contacts :1, l. These instrument parts, also the scale plate lgare mounted on an insulating base it that is secured to the supporting base i 5) by bolts ii that, as is customary, may serve as the terminals for the moving coil l. Spacer sleeves 62 on the terminal bolts ll provide a clearance space between the supporting base 3 and the instrument relay base it for receiving the i'ielci coil it of a small synchronous motor M of the self-starting type. This motor is of the general type shown in the patent to Warren, No. 1,495,986, granted May 27, 1934, and includes a laminated field it, a rotor (not shown in Figs. 1 to 3) on a rotor shaft (see Figs. l and 5) that is connected to a power shaft l5 by r duction gearin. E5 in the gear case l6. it is usually conven ent to employ a synchronous motor such as design '7 electric clocks, l. e., one having a reducti gear designed to rotate the power shaft one revolution per minute, but other gear ratios may, of course, be used.

The power 25 carries, in single unit, mechanism for separating the magnetic contacts fill the instrument relay, operating means for a holdlng switch to maintain the energization of the motor for a predetermined interval after the separation of the relay contacts and, if desired, a load or alarm circuit switch operator. As illustrated in Figs. .1 to 3 and 6, this unit comprises a block or cylinder ll of insulating material securecl to the shaft to by a set screw ll and carrying one or more pusher arms having bent ends for moving the pointer of the instrument relay counterclockwise to separate the magnetic rider ll from the magnet contact l. Four pusher arms it are illustrated but the number may be varied in accordance with the speed of rotation of the power shaft 95 and the desired con- 4n trol interval. Supplemental radial arms it are carried by the block ill for rocking the bell crank lever 26 which constitutes a pusher arm for separating the pointer El and rider 6 from the magnet contact 7'.

The holding switch assembly includes a contact plate 29 at the outer face of the cylinder ill, the plate having four radial notches at which portions 22 of the insulating block l'l'are exposed. The spring contactsZIi, 24 of the holding switch are carried by an insulating strip 25 that is mounted on the motor strap 26 in which the power shaft i5 is pivotally supported. The contact 23 is in continuous engagement with the central portion of the contact plate 2| and contact 24 is positioned to engage the insulating sections 22 as the cylinder I'I rotates. The angular arrangement of the pusher arms l8 and the insulating sections 22 is such that the contact strip 24 engages an insulating section 22 to interrupt the motor circuit when a pusher arm i8 is adjacent the magnet contact I but spaced from the path of movement of the pointer 5. The circumferential length of the insulating sections is so short that the clockwise rotation of power shaft l5 and cylinder I! will bring the contact disk 2! beneath, contact 24 before the pusher arm l8 separates the relay contacts, thus c mpleting a holding circuit for the motor which, with the illustrated four sets of pusher arms 58 and notches in the disk 2|, corresponds to a 15 second control interval for one rotation of shaft I5 in sixty seconds.

The relay contacts may be included in the motor circuit, as indicated in Fig. 5; but the embodiment shown in Figs. 1 to 4 includes an auxiliary relay for completing the motor circuit. This auxiliary relay comprises a solenoid 21 mounted on an insulating plate 28 that is secured to the supporting base I, and a pair of armature or pivoted contact arms 29, 29'. Contact 29 engages a fixed contact 30 to complete the motor circuit when the solenoid 21 is energized, and contact 29' cooperates with contacts 30a, 30b to close the alternative circuits from a power source, indicated schematically as an alternating current supply 3i, and the alarm or control devices 32a, 32b, respectively.

A terminal plate 33 of insulating material is preferably secured to the base I to carry a plurality of terminals 33'-which facilitate the assembly and wiring of the control device. When, as is preferable for high sensitivity and freedom from sparking, the circuit of the relay contacts is traversed by direct current, a small rectifier unit 34 of the copper oxide type is mounted on the base I, and is supplied with low voltage alterpointer 5 to separate the relay contacts.

nating current through a step-down transformer 35 that is fed from the usual power and light of the auxiliary relay. The load or alarm circuit through device 30a is normally closed, and, when the control impulse to ',the relay coil 4 reaches su'ch value that the magnetic rider 8 enters the field of the contact 1, these contacts engage to complete the energizing. circuit of the solenoid 21. The armature contacts 29, 29' are drawn into engagement with contacts 30, 30b, respectively, thus completing the circuit for the motor and the alarm or control circuit through the device32b. The power shaft ii of the motor is thereby rotated to bring the contact disk 2i beneath the holding circuit contact 24, and, shortly thereafter, to carry a pusher arm l8 against the solenoid circuit is thereby opened, also the original motor circuit at contacts 29, 30, but the motor continues to rotate until the holding circuit is opened by the movement of an insulating section 22 into engagement with the contact 24.

The wiring diagram of Fig. 4 does not show The the high contact 1 nor the pusher mechanism but the operation is exactly the same when the rider 6 engages the contact 1'. The control impulse to the moving coil 4 may be produced in various ways, as is well known in the art. The moving coil 4 may be connected across a thermocouple in temperature control systems, across a voltage divider in voltage regulating systems, a photocell in light responsive systems, and across other variation producing devices in other control or alarm systems.

As shown in Fig. 5, the auxiliary relay may be omitted when load or alarm circuit contacts are controlled by the unit that is secured to the power shaft l5 of the motor. The cylinder 11' of insulating material carries the pusher arms, not shown, the contact disk 2| and also a series of circumferential contact segments or rings 39, 40, 4| for engagement with contact blades 42 that may be connected to a power supply and to alternatively operative control devices.

It is to be understood that the invention is not restricted to the particular embodiments herein illustrated and described, and that other physical constructions and circuit arrangements fall within the spirit of my invention as set forth in the following claims.

I claim:

1'. A relay system including an instrument type relay having contacts operative when engaged to complete an energizing circuit for a motor, a motor included in said circuit and having a rotor shaft geared to a power shaft, switch means including a member actuated by said motor for completing a holding circuit for energizing said motor for a predetermined period independently of the engagement of said relay contacts, and means including a pusher arm actuated by said motor for separating said instrument contacts; said member of the switch means and said pusher arm comprising a unitary assembly mounted upon said power $18..

2. A relay system of the type including an instrument type relay having magnetic contacts, a miniature motor having. a rotor shaft and a power shaft geared to the rotor shaft, means actuated by said motor for separating the relay contacts and an energizing circuit for said motor controlled by said relay contacts, characterized by the fact that said contact-separating means comprises a pusher arm assembly secured to said power shaft, said. assembly including switch means for opening the energizing circuit of said motor.

3. A relay or control system comprising an instrument type relay having magnetic contacts, a motor having 'an energizing circuit adapted to be closed upon an engagement of said relay contacts, said motor having a rotor shaft and a power shaft geared to said rotor shaft, means actuated by said motor for separating said relay contacts; and switch means including a member actuated by said motor for completing an energizing circuit for said motor independently of the engagement of said relay contacts; said contact-separating means and said switch member comprising a unitary assembly mounted directly upon and supported by said power shaft.

4. In a relay system, the combination of a supporting base, a relay having a pair of relatively movable contacts, a motor-and means actuated thereby for separating said relay contacts, means for mounting said relayand motor on said supporting base, an energizing circuit for said motor including switch means controlled by said relay area-ire contacts, and a holding circuit for said motor including operating means actuated icy said motor, said holding circuit operating means and said contact separating means constituting a unitary assembly.

5. A relay system including a relay having a pair of spaced magnet contacts and a pointer carrying a rider contact of magnetic material, a motor energized by an engagement of the relay contacts, a holding circuit switch actuated by said motor for energizing the sameior a predetermined period upon initial energization of saidmotor by. said relay contacts, a rotatable pusher arm actuated by said motor for separating said pointer and its rider contact from one of said magnet contacts, a rocker arm for separating said pointer and its rider contact from the other magnet contact, and an arm rotated by the motor for actuating said rocker arm.

6. In a relay system, a relay for moving a pointer carrying a magnetic rider contact between two stationary magnet contacts, and means for separating said magnetic contact from said magnet contacts; said means including a rotating shaft, a pusher arm on said shaft forseparating said rider contact from one magnet contact, a rocker arm having one end for sepa= rating the rider contact from the other magnet contact, and an arm on said shaft for actuating the other end of said rocl-zer arm.

71121 a relay system, an instrument relay hav= ing a contact arm for engaging a fixed contact, an auxiliary relay having a solenoid included in a circuit controlled by said contacts, said auxll= iary relay having contact arms ,engagea'ble respectively with two sets of switch contacts, a motor for separating said instrument relay contacts, an energizing circuit for said motor including one set of said switch contacts, a holding circuit switch actuated by said motor for energizing the same for a predetermined period upon initial energization of said motor by said set oi switch contacts, and a load circuit in cluding the other set of switch contacts.

8. A relay system as claimed in claim 7, where in said contact arm. carries a contact rider oi magnetic material and said fiXiEd contact is a magnet.

9. In a relay system, an instrument relay having a contact arm for engaging a fixed contact, a motor having an energizing circuit including said relay contacts, said motor including a rotor shaft geared to a power shaft, means carried by said power shaft for separating said relay contacts, a load circuit switch including an operating member mounted on said power shaft, and a holding circuit for said motor including an actuating member mounted on said power shaft, said actuating members and said contact-separating means comprising a unitary assembly.

1-9. A relay system as claimed in claim 9', wherein said unitary assembly includes an insulating member secured to said power shaft, and said contact-separating means includes a radial arm supported by said insulating memoer.

ii. In a relay system of the type including a relay having magnetic contacts and a motor for separating said contacts, a pusher arm and switch unit for mounting on a shaft or said motor; said unit comprising a block oi insulating material and means for securing the same upon said shaft, a pusher arm mounted on said block, and, switch operating means carried by said bloc 12.4% relay system as claimed in claim 11, wherein said switch operating means comprises a radially notched conductive plate secured to the end of said insulating block.

13. A relay system as claimed in claim 11;121 combination with an auxiliary arm mounted on said block for actuating another contact-separating means.

ANTHONY H. LAMB.

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