US1672675A - Safety system for electric elevators - Google Patents

Description

June 5', 1928; I 1,672,675

- C. C. CLYMER SAFETY SYSTEM FOR ELECTRIC ELEVATORS Fil'ed Dec. 15, 1926 Whom Invenbom Charles C.Cl5mer-;

y M Z His Attorney:

, Patented June 5, 1928.

. UNITED STATES PATENT onion. 1

cmLEsc. (mutant, of SCHENECTADY, NE YORK, assIenoB T0 GENERA ELECTRIC,

, COMPANY, a CORPORATION on NEW .YORK. 7

, sArnrY SYSTEM FOR nLnc'rRionLEvArons.

Application filed De em er 15, 1336. Serial No. 155,062.

My-invention is directed to improvements in safety systemsfor electric elevators for the prevention of accidents due to improper manipulation of an elevator controller in 8 connection with the closing of the elevator door or gate.

'Sys t ems have heretofore been provided whereby the elevator motor cannot be energized to effect operation of the elevator in 10 casethe-elevator door or gate is in its open positiomit being necessarythat all of the gate contacts be closed before the controller is operated to efi'ect operation. of the elevator motor. Systems have also been hereto- 16 fore provided whereby in case the elevator controller is first moved to an operative position 'andfthe gate contacts are afterwards closed by the closing of an elevator door or gateQthe elevator motor cannot be energized 20 until after the controller is returned to its oil or neutral position. Such former systems 'have left'much to be desired in the direction of simplicity of construction and arrangementyand in the reliabilityof-the operation thereof. 5 i 1.

\ The objects of my inventionis to provide animproved system having features of simplicity of construction and arrangemenfiand reliability of operation for taking careof the above condition, among others;

"In carrying my invention into effect in the form which I now regard as the preferred form thereof, I provide a relay which has its Winding connected in multiple relation wit-h the winding or windings of the electroresponsive switch mechanism which effects the connection of an elevator motorto its source of supply for the desired direction'ofop eration, and connect this multiple circuit in series relation with a resistor connected in the circuit of the gate contacts. The arrangement is suchthat in case the elevator controller is first moved to an operative posi.

the resistor will prevent operation of the electro'responsive motor controlling mechanism to connect the motor to its source of supply, and also prevent'operation of the relay by limiting the current through the windings ofthe switch mechanism and the 'tion and the gate contacts are then closed,

relay.'- That will necessitate that the controller'be returned to its off- 01' neutral position, thereby opening one of the multiple paths so that the windingof the relay is now connected in series relation with the resistor and the gate contacts, and this relay will then be sufliciently energized'to 0perate and shunt the resistor. If the elevator controller is then moved from its neutral position to an operative position, the windings of the electroresponsive motor controlling mechanism will be sulficiently energized to efi'ect op'eration thereof. It the gate contacts are all first closedwith the motor controller in its neutral position, therelay will operate to shunt the resistor and thus permit operation of the electroresponsive motor controlling switch mechanism when the controller is subsequently operated to an operative position.

Among the advantages of my invention are the following: The scheme is very simple and readily understood by electricians whose duty it is to install and keep electric elevator equipment in operation. The sysl6 tem is'readily adaptable to existingsystems which either do not have protective arrangements for preventing improper operation of an elevator controller, or for taking the place of apparatus in morecomplicated systems intended to take 'care of the general conditions outlined above; Another advantage'of the invention is that in'case for any reason the governing relay either sticks in its closed position, or the winding'thereof is burned out and the relay does not close, a certain measur'e'of protection is nevertheless had since the motor controller is inoperative to effect operation oif the elevator until after the gate contacts have been closed.

In the accompanying drawing I have shown a very simplified system of motor controlfor an electrified elevator, hoist or the likefwherein my invention is incorporated as one of the elements thereof.

1 Referring to" the drawing, the elevator cage 10 is, arranged to be operated "in the switch 13-which governs the eleotrorespon-v sive motor controlling switch mechanism indicated as the directional or reversing contactors 14 and 15. The safety relay 16, together with the. resistor 1.7v controlled thereby, are provided for insuring that the'controller 13 must be in its neutral position, as indicated, and the gate contacts 18 all closed beforeeitherr contactor' 14H'or15' can 'b efener' gized to efi'ect operation ofm'otor 'll'it'or' either It will y direction of operation otthe elevator. be observed that the winding ofrelay" 16 is connected in multiple relation with the windings of either the contactor 14 or contactor 1 5'- loy:= the: operation of controller 13. It

will: also be; observed that this multiple circuit is: included in series relation with the resistor lZiand thegate-contacts '18. When the relay 16 .operates, ,itshunts-.theresistor w-AS thus constructed and arranged, .and

with th eeparts in their respective positions indioa tedwin the drawing,-the operation of my invention isas follows: Assume that it isdesi-red to. operateithe elevatorin up directiom: Thelower gate contact 18. will first beclosed by first closingrthe elevator door or gate, and thisiwill connect the winding ofthe-relay 16 acrossthe supply circuit .19 in series relation with theresistor 17. The value of this resistor is such that with the; controller 13 a in its neutral position, sufficient current: will flow through the wind ing of relay 16 to effect operation of the relay. andz the; consequent shuntings offlthe resistor 17; It, now, the manually operated controller 13 is moved to its first clockwise positiomthe. directional-' contactor will bev energizedutoclose and 1 connect thermotor armature to the source of: supply through the;contacts ofthiscontactor and thestartin'g; resistor 20. This isgthe vproper sequence of: operation ofthe parts in-orden to efiect operation of the elevator, It,v instead of that-proper operation, thecontroller 18 is firstwmoved to an, operative position, before the lowergate contact 18,. is closed, neither the winding; ,of directional contactor 15 ,nor; the winding-of relay 16 will receive sufficient;v energization to effect operation of these, devices. That is because of, the fact that: tl'1e-,Wil'lCllIlgi Of contactornle and the windingof relay;v 16 v are connected to. the same conductor ofthe source of supply, and when thelowen' gate contact 18 is closed,

thesetwo windings will be in. multiple rela tioniwith each other and. the multiple cir- C'LlltdSvlIlseries, relation with. the resistor 17 and the gatecontacts 18.v Under these conditions, the.resistor 17 will prevent sufficient energization of contaotor 15 and relay 16 for: operation thereof Ifthe con- ;troller.13 isreturned to its neutral position I is the circuit; through the winding of contactor l5 is open and the winding of relay 16 is now sufficient-1y energized to eii ect the closing of the relay and the shunting of the resistor 17 so that when the controller is ]ing -switch mechanism, and gate contacts for insuring that the elevator cannot start until after the gate contacts have been closed. Itlwill, also be observed that the system is readily applicable for the replacement of more :complicated and less, reliable 'systems previously installed for accomplishingthe general purpose. A further feature-is that in caselany gate or door contactsareopened after the elevator isv in operationptherelay 16 and, the selected directional c ontafctor will be-immediately opened'andth e elevator stopped. If, the relay- 16 isv closed, tlie,controllerv 13 being in its neutral position, 1 and anygate or door contacts are opened, the relaywill immediately" open, thnsi prevent- .ing; ,unsate operation. q

, hat I claimas new and desire to securetby Letters Patent of thefl liiited States In combination in safety, system for the control of electric elevators, electroresponsive. reversing switch mechanism for controlling the direction of operation ofthe elevator, a reversing manual controller for controlling i said switch mechanism, a safety electromagnetic relay, a resistor, gate. contacts, and electr cal connections between said. controller, the. operatingwindingsof said. switch mechanism, the winding oflsaid relay, 2 and said resistor whereby the resistor prevents sufficient energization of said, reversingr switch m'echanisnr for operation thereof in case said gate: contacts lare closed vatoroperative position, therebynecessitating the return oi said controller to a neutral position to effect suflicient energization of said relay to shunt said resistor and per- .mit sufl'icient energization of said switch mechanism for operation thereof when said elevator operative position witli the said gate contacts Imaintained: closed, I

2. In combination in a safety system for electric. elevators, an electric motor: for operating are. elevator, electromagnetic switch mechanlsm 'for controlling the connection after said; controller is operatedtoaanv elecontroller is subsequently operated. to an gate contacts in series relation across said source of supply, the operating winding of said switch mechanism being connected to be included in multiple relation with the Winding of said relay when said controller is in an operative position, whereby in case said gate contacts are closed after said controller is operated to an operative position, said resistor prevents sufiicient energization of said switch mechanism and said relay for operation thereof, thereby necessitating the return of said controller to a neutral position to permit said relay to shunt said resistor.

In witness whereof I have hereunto set my hand this 14th day of December, 1926.

' CHARLES c. CLYMER.

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