US2298111A - Elevator control system - Google Patents

Description

Oct. 6, 1942. w. F. EAMES A 2,298,111

ELEVATOR CONTROL SYSTEM 2 SheeLs--SheeiI l Filed Aug. 19, 1941 d 5,/ BWZM ATTNEY Oct. 6, 1942. w F EAMES I 2,298,111

ELEVATOR CONTROL SYSTEM FiledrAug. 19, 1941 2 Sheets-Sheet 2 1J M e E11/1D /P 2F34 mr fc w UF6/751 Bpdrap l l l j 20L apen.; Z/Odra/zs.

Patented Oct. 6, 1942 UNITED STATES PATENT OFFICE ELEVATOR CONTROL SYSTEM William F. Eames, Westfield, N. J., a'ssignor to Westinghouse Electric Elevator Company, Jersey City, N. 1., a corporation of Illinois Application August 19, 1941, Serial No. 407,414 (ci. 172-152) 14 Claims.

Another object is to provide a leveling and releveling system which will require the use of less complicated floor selectors and circuits than those heretofore found necessary for use in leveling and releveling systems.

A further object is to provide a. system which will automatically cause an elevator car, in making a one-floor run, to accelerate to its most desirable speed, then decelerate at its most desirable rate for a one-iloor run when the car switch is moved to its on position and then promptly returned to its center or "nl f position.

A still further object is to provide a system in which compensation may be made for temperatur'e changes which ailect the leveling action.

It is also an object to so control the energization of the generators embodied in variable voltage elevator systems as to secure the most desirable deceleration of the elevator cars when making stops at their iloor levels.

Other objects will become apparent from the following description of the invention taken in conjunction with the accompanying drawings. in which:

Figure 1 is a diagrammatic representation in what is known as the straight-line style of control system for an elevator car embodying my invention;

Fig. 1A is an explanatory illustration of the relays embodied in the control system of Fig. lthe illustration shows the relays with their coils and contact members disposed in horizontal alignment with their positions in straight-line circuits oi Fig. 1, so that the identication of -any relay and the position of its coil and contact members in the straight-line circuits may be readily determined;

Fig. 2 is a diagrammatic representation of an inductor relay to/ be mounted on a car and a pair of inductor plates therefor mounted upon the walls of the hatchway in which the car operates as looking from the car; and

Fig. 3 is a reduced view in side elevation of the inductor relay shown in Fig. 2.

the hatchway Wall toward Y The relays embodied in the system are designated as follows:

U =up direction switch D :down direction switch UR:up direction relay or control device DR:down direction relay or control device M :car running relay N :auxiliary car running relay GR=high speed start relay 1P :low speed decelerating relay 2P :intermediate speed decelerating relay '3P :high speed decelerating relay L :leveling inductor relay LU=up leveling relay LD=down leveling relay TA:time delay relay for one-floor runs TB=antiplugging relay TC:smooth-start relay Q :counter-electromotive force relay K :door-operating relay.

Referring more particularly to the drawings, I have illustrated a car C for serving a plurality of landing floors as suspended by a suitable cable Il which passes over a hoisting drum I2 to a suitable counterweight i3. A hoisting motor H is provided for operating the hoisting drum by means of a shaft Il to raise and lower the car. 'I'he hoisting motor H is provided with a eld winding HF which is connected for constant energization to a pair of supply conductors L+ and L-, which may be connected to a supply of electrical energy by a pair of line switches l5 and I6.

A variable voltage system of control is provided for controlling the operation of the hoisting motor H, wherein the hoisting motor armature HA is connected in a closed circuit 2| with the armature GA of a generator G. The generator is provided with a separately excited field winding GF which is connected for energization in a loop circuit 22 with the armature RA of a regulator R, so that the output of the generator and, consequently, the speed and direction of operation of the hoisting motor H may be controlled by controlling the operation of the regulator. An adjustable resistor rl is connected in the circuit of the generator field winding for adjusting the resistance of that circuit to any desired value. A commutator pole winding 24 for the generator G is connected in series in the loop circuit 2|. The armatures of the generator and the regulator may be mounted on a common shaft 26 for operation by any suitable constant speed motor (not shown).

The regulator R is provided with a self-exciting iield winding RCF, a pattern eld winding RPF, a differential eld winding RDF, and a series eld winding RSF.

The self-exciting iield winding RCF is conlnected in the loop lcircuit 22 in series with the regulator armature RA and the generator iield winding GF. The total resistance or' this circuit should be made equal to the volts that the regulator will produce when one ampere hows through its self-exciting field winding. It has been found that with this adjustment perfect regulation will be obtained with no hunting effects.

The pattern eld winding RPF is disposed to be connected across the supply conductors L+ and L-, so that the generator voltage and the direction of operation may be controlled by con-y trolling the direction and the value of the current in the pattern field. For a given excitation of the pattern iield, the regulator will produce a voltage which will excite the generator field winding GF. As soon as current starts to ow through the generator field winding circuit, the self-exciting iield winding RCF excites the regulator to force the current through the generator field winding. Y

A plurality of resistors rt to ri@ are connected in the circuit of the pattern held winding to so control the value of that winding that the generator G will be energized to cause the car to accelerate, run and decelerate at predetermined desired speeds. Y

The differential field winding RDFis connected across the terminals of the generator armature GA. An adjustable resistor ril is inserted in series with the differential field winding RDF, 'so that the value oi the dierential :deld wind ing may be adjusted as desired. This diierential iieid winding and the pattern ileld winding RPF are adjusted to produce the same and opposite voltage in the regulator tor a given excitation or the pattern field. i

The regulator series field RSF is connected in series in the loop circuit 2l between the armatures or the generator and the hoisting motor. rihis field winding is provided to cause the regulator to give the generator neld winding suril= cient excitation to compensate for the m drop in the hoisting motor. The regulator R is disclosed and claimed in Danilo Santini Patent Nm 2,221,610, granted November l2, 1940, and assigned to Westinghouse Electric Elevator Conipany. Further details regarding the regulator and its functions, if desired, may be secured in the patent.

An electromagnetic brake l@ having a coil iQa is associated with the shaft i5 for stopping and holding the car when the power to the hoisting motor is out on. A pair of resistors vll and f5 are disposed in the circuit of the coil ita to cause a quick brake action under certain conditions hereinafter donned.

A car switch CS is mounted in the car for use by the car attendant to start and stop the car. The car may be started in the up direction by moving the car switch counter-clockwise and in the down direction by moving it clockwise. When the ear switch is centered, it causes the l car to stop at the next door.

The up direction switch U and the down direction switch D control the energization. of the generator G hy connecting the pattern iield winding of the regulator to the supply conductors L+ and L- for'up direction or down direction operation.

The car running relay M is controlled by the direction switches U and D, and is provided for controlling the brake IS and preparing certain circuits for operation when the car switch is thrown for movement of the car.

The auxiliary car running relay N ls controlled by the relay M, and is provided for further preparing the control system for operation after the action of the car running relay M.

The high-speed starting relay GR is controlled by the direction switches U and D, and'ls prountil the car has gotten started at low speed The relay TC should have a time delay of ap proximately .3 second in opening after it is deenergized.

The door relay K is provided for controlling the door operating motor (not shown) to cause it to open the doors at a floor when the car maires a stop thereat, and to prevent it rrom .opening the doors while the car .is running or is conditioned to start.

The counter-electroniotive force relay Q is connected across the loop circuit 2i to prevent operation oi the door relay E to open any door while the hoisting rnotor is operating above a predetermined low speed.

vany suitable landing system for causing the carto stop level with the floor after the car switch is centered ior a stop may be employed. However, l have illustrated as one suitablesystem the automatic inductor relay system described and claimed in the copending application of Danilo Santini, died Sept. d, wel, Serial No. 409,491, and assigned to the Westinghouse mectric Elevator Company. This landing system includes the inductor relay L which may be mount ed on top of the elevator car Cv in position to come adjacent to an up inductor plate E and a down 'inductor plate F mounted on the walls of the hatchway (not shown) at each oor landing by means of a plurality o angle braces 23. In this particular illustration it will he assumed that the inductor plates E and F are each about 2l inches long and that the inductor relay is about '7 inches long, The plates should he so mounted in vertical, overlapping position in the hatchway, and the inductor relay L should be so mounted on the car that the relay will pass between the plates and close to them without touching them as the car moves up and down in the hatchway. Furthermore, the relative position of the relay and the plates should be such that if the car oor is level with oor landing at which the car is stopped, the center of the relay, as indicated by the line x--x will be midway between the upper end of the inductor plate F and the lower end'of the inductor plate E, as shovm in Fig. 2.

The inductor relay is provided with two pairs of contacts EUL and HDL on im upper end and with two pairs of contacts IUL and ZDL on its lower end. An amature 32 is provided for each pair of contacts. The armatures for operating the contacts ZUL and IUL should be disposed in position to be operated by the inductor plate E and the armatures for operating the contacts 2DL and IDL should be disposed in position to be operated by the inductor plate F when the coil of the relay is energized and the car moves the relay into position adjacent the inductor plates.

Although the drawings illustrate the plates E and F for only one iioor landing, it is to be understood that a set of these plates is mounted at each oor served by the car and that they will be effective to stop the car only when the coil of the inductor relay L is energized to cause the car to stop.

The inductor contacts are normally closed and when the car comes down to a stop at the oor level the contacts open in the following order: IUL, 2UL, 2DL and IDL, When the car comes to a stop at the floor level, the contacts open in the following order: IDL, 2DL, ZUL and IUL.

y 'I'hese actions deenergize the speed relays in the order 3P, 2P, IP and the appropriate direction switch regardless of the direction of travel.

The high speed decelerating relay 3P controls the decelerating resistance r2 included in the circuit of the regulator series iield winding RSF, the resistance r3 in the regulator differential field winding RDF, and the resistor 1'8 in the circuit of the regulator pattern field winding RPF to cause the car to decelerate from high speed to intermediate speed.

The intermediate speed decelerating relay 2P controls the resistance r9 in the regulator pattern ileld winding RPF and also conditions the circuits for switches U and D, and relays yM and N.

The 10W speed decelerating relay IP controls the resistance rIII in the circuit of the regulator pattern eld winding RPF and the use of resistances r4 and f5 in the circuit of the brake coil I9a.

The time delay TA has a time delay of approximately 1.8 seconds when opening and is designed to provide a holding circuit for the up direction relay UR or the down direction relay DR when the car switch is thrown to its. starting position and immediately returned to its center position for a one-floor run` This time delay relay holds the up or the down direction relay UR or DR energized for the amount of time necessary to cause the car to make a one-floor run. Under this predetermined set-up, the car will accelerate to and run at its high speed for a one-iloor run and then decelerate at the proper time to a stop at the next floor.

The up leveling relay LU and the down leveling'relay LD are controlled by the up contacts IUL and the down contacts IDL on the inductor relay L to cause the car to relevel if it rises above or sinks below the floor level at the landing at which it is stopped. If the car moves up for, say, 1/2 inch the contacts IDL will pass beyond the upper end of the plate F and will thereby be operated to cause the down direction switch D to move the car down to its floor level. vOn. the other hand, if the car moves down, say, 1/2 inch below the oor, the contacts IUL will be operated by passing beyond the lower end of the plate E to operate the up direction switch 4 ,to cause the car to return upwardly to its floor level. Obviously, when the car returns to its correct level position it will so position the inductor relay L that all its contacts will be within the limits of the conductor plates E and F, and none of them will then operate to control the car.

(Sil

The anti-plugging relay TB is provided with a time delay of approximately .3 second and operates to prevent energization of the inductor relay L when the car is traveling at full speed and for a fraction of a second after retardation starts so that the releveling switches cannot plug the hoisting motor at too high a speed.

'I'he relay 3P is also provided with contacts 3PA in the circuit of the up direction relay UR and DR which permits the release of the one floor run holding circuit provided by the relay TA whenthe car is closer to a floor than its normal one-iloor run distance when it is started toward that oor.

It is believed that the invention will be best understood lby the following assumed operation of the system illustrated in the drawings. It should be noted, however, that the particular dimensions, periods of delay, amounts of resistance involved, etc., are given as an illustration of what may be included in an operating system but that other values may be readily used in adapting the system to meet various operating conditions.

It will be assumed that the switches I5 and I8 are closed to prepare the control circuit for operation. This action energizes the hoisting motor eld winding HF, the inductor relay L, the one-floor run relay TA and the smooth start relay TC. It will be assumed that the car is starting at the eighth floor landing level with the door. Therefore, the inductor contacts IUL, 2UL, IDL and 2DL are all operi because of the energized condition of the inductor relay L and its position between the inductor plates E and F for that floor (see Fig. 2).

It will be assumed now that the car attendant, desirous of making a one-iioor run, closes the car switch CS in anti-clockwise direction to move the car down to the next floor. Inasmuch as this is tov be a one-floor run, the attendant will close the switch only temporarily and then return it to its oil' position. The length oi' time the switch stays closed is not critical, but it must @be centered before the car runs more than one- L+, URS, DR, 33, L-

The energized down direction relay DR opens its Ibaci: contacts DRI and DR3 and closes its front contacts DRI, DR4, DRS and DRB. The closing of the contacts DRE energizes the door relay K to cause the door motor (not shown) to close the car gate and the iloor landing door (not shown). The closing of the contacts DRZ prepares the circuit of the down direction switch D for operation. The closing of the contacts DR4 prepares the starting relay GR for operation. The closing of the contacts DRS energizes the anti-plug ging relay TB.

The energized anti-plugging relay TB opens its back contacts TB3 thus deenergizing the inductor relay L which causes the decelerating and leveling contacts IUL, 2UL, IDL, 2DL on the inductor relay to reclose, thus energizing the de-A celerating relays IP and 2P and the leveling relays LU and LD which will remain in that condition until the next stop is to `be made. This operation of the decelerating relays short circuits the decelerating resistors in the pattern field circuit to condition the decelerating means for action when the car is to be stopped.

It will Ibe assumed now that the door motor has closed the car gate and. the landing ioor door thereby operating a limit switch (not shown) to stop the door motor and also closing the car gate and door safety contacts d@ and di.

The closing of the contacts t@ and il completes the circuit for energizing the down direction switch D through L+, D, Us, par, te, sa, una, L-

'I'he energized down direction switch D closes its front contacts DI, D2, Dl, D5, DS `and D@ and opens its back contacts D3, Dl and D3. The closing of contacts D5 completes a self-holding circuit for the down direction switch D. The closing of the contacts Dit energizes the car run-Y ning relay M by the circuit L+, M, Dit, DRE, l, M, URE

The .closing of the contacts DI and D2 prepares the pattern eld winding RPF for operation in the down direction.

The closing of the Contact members D9 energizes the decelerating relay 3P by the circuit L+, LUs, De, s?, L-

The relay 3P opens its contacts SP2 around the resistor r3; opens its contacts SPE to insert the resistor r2 in series with the regulator :Held winding RPF, and closes its contacts 3P3 to short circuit the resistor rd in the pattern circuit. These connections are prepared to secure certain desired operations during deceleration of the car as will be described later when the car is decelcrated to a stop at the next floor.

Returning now to the energized car running relay M, that relay opens its back contacts Mi and closes its front contacts M2, M3 and MAG. The opening of the contacts Mi inserts the resistor r3 in series with the regulator differential field winding RDF for a purpose to be described later. The closing of the contacts M2 prepares the brake coil lila for operation. The closing of the contacts completes the circuit through the pattern iield winding RPF for the down direction as follows: L+, D2, RPF, Di, M3, r6, rl, TCB, L-

The energized relay N closes its front contacts Nl and N2 and opens its back contacts N3 and Nd. The closing of the contacts Ni energizes the generator field winding GF by the circuit RA, RCF, Ti, GF, Ni

The generator now starts to deliver energy to the hoisting motor for operating the car downwardly. At the same time, the relay N closes its contacts N2 thereby energizing the brake coil i230; by the circuit L+, Na, en, sec, M2, n

The energization of the coil i9@ releases the brake i9 and the carstarts to move downwardly. The opening of the contacts Ni deenergizes the smooth start relay TC and after the expiration of .3 second that relay opens its contacts TCI which aaeaiii of the pattern field for starting purposes in order vto secure a smooth start. The deenergization of the relay TC also closes its back contacts TCZ which thereupon complete the energization of the starting relay GR by the circuit thereby short circuiting the resistors r1, T8, r9

and ri in the pattern eld winding RPF. This increases the energization of the pattern iield circuit which causes the generator G to increase the speed of the hoisting motor H to its high running speed.

The car is moving downwardly now but it will be recalled that the one loor run relay TA was deenergized by the opening of the contacts N3 when relay N was energized. The relay PA will now, at the expiration of 1.8 seconds, when the car is about half way between the oors, operate to open its contacts TAI which were holding the down direction relay energized. It will be recalled that the car switch was closed only temporarily and that, therefore, the only circuit for the down direction relay DR passed through the contacts TAE. Therefore, the present opening of these contacts deenergizes the down relay DR which thereupon closes its back contacts DRI and DRS -and opens its front contacts DR2, DRl, DRS and DB6.

The opening of the contacts DRl deenergizes the starting relay GR which thereupon opens its contact members GR! to eliminate the short circuit around the resistors rt, rl, T8, r9 and rli.

had included the resistors 1'@ and rl in the circuit 75 However, it will be observed by the drawings that inasmuch as the decelerating relays IP, 2P, and 3P are energized, the resistors f8, r9 and ri now stand short circuited by the decelerating contacts, but that the resistors r6 and r are completely included in the pattern field circuit. The effect of the resistors r6 and rl is to reduce the speed of the car as it approaches the iirst point at which the inductor relay L starts decelerating the car. This point will be the upper end of the plate E and will correspond to a position of the car approximately 21 inches from the next oor.

Theropening of the contacts DB5 deenergizes the anti-plugging relay TB which, after the expiration of a .3 second delay, closes its back contacts TBS thereby re-energizing the inductor relay L so that as it is brought opposite to and moved along the inductor plates E and F, its con tacts will be operated sequentially to decelerate the`carto a down stop at the seventh floor.

As the car approaches to the point approxirnately Z1 inches from the oor landing, the inductor relay L approaches the inductor plate E, and as the contacts iUL come exactly opposite the upper end of the plate E, they are operated by the ux induced in the plate through the energized relay, to move to their open position, thus deenergizing the leveling relay LU to open its front contacts LUI and LUS and close its back contacts LU?. The opening of the contacts LUS deenergizes the high speed decelerating relay 3P which thereupon opens its contacts 3123 thus inserting the resistor 18 in the circuit forthe pattern eld winding to decelerate the car from its high decelerating speed to its intermediate decelerating speed.

At the same time, the deenergized relay 3P recloses its contacts 3Pa, to short circuit a portion of the resistor r3 in series with the differential field winding RDF thereby strengthening that' regulator field winding for the purpose of rendering the deceleration more effective. This action may be described as producing a tendency to huntin the regulator but the action is directed cppositely to the cars movement so that the carretards at a higher rate than normal. It would ultimately reverse its direction of travel except the brake applies quickly when the car reaches oor level. which holds the car at iloor level and prevents reversal.

Also at the same time the deenergized relay 3P recloses its back contacts SPI and short circuits a portion of the resistor r2 in circuit with the series eld winding RSF to strengthen that series field winding to keep' the regulation ilat.

As the car decelerates from its high decelerating speed to its intermediate speed, it approaches to within approximately 14 inches of the down stop at the seventh iloor and thereby moves the energized inductor relay L downto such a point that its contacts IUL come opposite the upper edge of the plate E and are operated to open position by the induced flux passing throughthe plate and the armature attached to the contacts. The opening of the contacts 2UL deenergizes the decelerating relay 2P which thereupon opens its contacts ZPI, 2PZ, and ZPB.v The opening of the contacts 2PI re-inserts the resistor f8 in the circuit of the pattern field of the regulator thus causing the regulator to decrease the amount of power supplied to the generator and thereby decrease the speed of the hoisting motor H and the car C from intermediate speed to low speed.

As the car approaches still closer to the seventh floor, the counter electromotive force relay Q is operated to open its contacts QI- in the circuit of the door relay K to prepare that relay for operation.

As the car drops still lower and arrives at a point about 7 inches from the seventh floor, it moves the energized inductor relay L downwardly to a point where its contacts 2DL come opposite the top of the inductor plate F and are thereby operated to their ope'n position, thus deenergizing the decelerating relay IP to decelerate the car to landing speed. The deenergized relay P opens its contact members IP4 in the circuit of the door relay K and also opens its contacts IPI to reinsert the resistor rIIJ in the circuit of the pattern field which reduces the speed' of the hoisting motor to what is known as stopping speed (approximately 15 feet per minute).

The deenergized relay IP also opens its contacts IPZ and IP3 in the circuit of the brake coil I9a thereby reinserting the resistors r4 and f5 in the brake circuit to weaken the brake coil for a quick dropout. It will be noted that the contacts BK operated by a mechanical switch (not shown) on the brake still remain open because the brake is still in released condition, thereby rendering effective the operation of the contacts IP2 and IPS.

As the car approaches closely to the floor and the iioor of the car comes within, say, one-half inch of the iloor level of the landing, the energized inductor relay L carries its contacts IDL the regulator pattern field circuit and causing the hoisting motor to stop. The opening of the contacts LDI also deenergizes the car running relay M and the auxiliary car relay N. Thereupon the deenergized relay N opens its contacts N2 thus applying the brake I9 to prevent further operation of the hoisting motor and the car.

The car is now stopped level with the oor because the operation of the inductor relay contacts IDL, as the car arrived within one-half inch of the floor, caused the shutting of! of the power and the application of the brake lto stop the car at the instant it leveled with the iloor landing. l

The deenergized relay N also recloses its back contacts N3 and N4 thereby reenergizing the one-oor run relay TA and the smooth start relay TC so that they will be ready for use when next needed in the operation o1' the car.

It should also be noted that the deenergization oi the car running relay M closes its back contacts MI thereby eliminating all of the resistor r3 from the circuit of the dierential iield winding RDF which gives that ileld full killing strength for any residual magnetism in the armature HA o! the hoisting motor. Also the deenergized relay N opens its contact members NI in the circuit of the generator field winding GF to stop the ow of energy through that field winding.

The car has new completed its one-run operation to a stop at the seventh oor.

The foregoing assumed action illustrates how my improved control system operates to cause the car to make a one-oor run in response to an over and back operation of the car switch in which the car attendant merely moves the opposite the upper end oi the plate F and they switch to its on position and then immediately returns it to its center position for a one-iloor run.

Assume now that the car overran its stop or that it drops, due to cable stretch in loading, while it is standing at the seventh iloor, say, more than one-half inch below the oor level. This causes the car to be releveled upwardly because when the car moves down the inductor relay contacts IUL drop below the lower end of the inductor plate E so that they are free from the iniluence of the plate. Under these conditions the contacts IUL reclose and thus energize the up leveling relay LU to immediately close its contacts LUI, thus energizing the up direction -switch U to close its contacts UI and U2 in the circuit of the pattern fleld winding RPF, thus preparing it for up operation of the car. The energized switch U also closes its contacts U3 and U4 thus energizing the car running relay M which, in turn, closes its contacts M4 thus reenergizing the auxiliary car running relay N. The energized relay M also closes its contacts M3 thus completing the energization of the pattern eld winding 'RPF oi! the regulator to cause the starting of the hoisting motor for moving the car in the up direction. The energized relay N closes its contacts N2 thus completing the circuit through the brake coil ISa and causing the brake I9 to be released so that the car may be returned to its position level with the floor landing. The energized relay N also opens its contacts N3 and N4 in the circuit of the one-floor run relay 'I'A and the smooth start relay TC thus preparing them for eventual operation after their time delay expires.

As the car moves upward in returning to its position level with the seventh oor landing, it carries the inductor relay L to the position where its contacts IUL come opposite the lower end of the plate E and are again opened thus deenergizing the leveling relay LU which, in turn, opens its contacts LUI thus deenergizing the up direction switch U, the car running relay M and the auxiliary car running relay N. The deenergized relay M opens its contacts M3 thus deen- I leveling operation takes place when the car, for

any reason, moves below the oor level of the landing at which it is stopped. 1f the car should drift away from the floor in lthe up direction for any reason, the contacts HDL on the inductor relay L Would be moved above the upper end of the inductor plate F and thereby cause energization of the down leveling relay LD to return the car to its iloor level. f

It will be assumed now that the attendant on the car again moves the car switch to its down running position and leaves it there for a down run from the seventh floor to the fourth oor. This is more than a one-oor run and, therefore, the operation of the one-oor run relay TA when it times out will have no eiect on the system. The movement of the car switch for the down iloor run engages the contact 33 thus energizing the down direction relay DR as previously described. The energized relay DR closes its contacts DRS thus energizing the antiplugging relay TB, opens its contacts T133 thereby deenergizing the inductor relay L which causes the closing of its contacts iUL, lDL, ZUL, 2DL and they, in turn, energize the up leveling relay LU, the down leveling relay LD, the low speed decelerating relay lP and the intermediate speed decelerating relay 2P, as previously described in connection with the one-floor run operation.

The energized relay DR also closes its contacts DRB thus energizing the door relay K to eiect the closing of the car gate and the floor door (not shown) thus closing the gate and door safety contacts it and il thus energizing the down direction switch D which, in turn, energizes the high speed decelerating relay 3P and the car running relay M. The car running relay M energizes the auxiliary car running relay N which, in turn, deenergizes the time delay relays TC and TA and also energizes the brake coil lSa to release the brake I9, all as previously-described in connection with the one-floor run.

The timing relay, TC now times out after the expiration of .3 vof a. vsecond and energizes the high speed start relay GR which closes its contacts GRl thus short circuiting the resistors rl,

18, r9 and rl@ in the pattern eld circuit of the regulator, which causes the car to run at its normal high speed as previously described. The deenergized relay TC also opens its contacts TCE thus partially preparing the pattern field circuit for use when the car is to be decelerated. Y

It will be recalled that the car attendant in making this more than one oor run to the fourth floor keeps the car switch in its closed position. Therefore, the opening of the contacts TAI in the holding circuit provided by those contacts for the down direction relay DR has no eiect on that relay.v

After the expiration of 1.8 seconds from the time the car was started, the one-floor run relay TA times out and opens its contacts TAI, but this has no effect an the operation of the car because the car switch remains closed on its contact 33 which keeps the down direction relay DR energized. A

When the car arrives at a position where it is from one-half to one oor above the fourth oor at which it, is to be stopped, the attendant centers the car switch CS to cause the car to stop at the fourth iloor. The centering of the car switch CS removes it from the contact 33 thus deenergizing the down direction relay DR which closes its back contacts DRE and DRS and opens its front contacts DB2, DRl, DRE and DB6. The opening of the contacts DRl deenergizes the high speed start relay GR which'opens its contacts GRI in its short circuit around the resistors in the pattern neld circuit. inasmuch as the dec'elerating relays 3P, 2P and iP are in energized condition, the resistors f8, r9 and rt@ still remain short circuited but `the resistors rt and rl remain in the circuit of the field RPF. This condition reduces the supply of energy to the pattern field circuit and thus causes a reduction in the high running speed of the hoisting eld motor and the car and prepares the car to be decelerated to the stop at the fourth floor.

The deenergization of the relay DR by opening its contacts DRS also deenergized the anit-plugging relay 'IB which at the end of .3 second closes its back contacts TB and thereby energizes the inductor relay L to effect deceleration of the car as it makes its down approach to the inductor plate E for the fourth oor. The operation of the inductor relay, its contacts and l the decelerating relays controlled thereby will follow exactly as previously described in connection with the stopping of the car at the seventh oor while making its one-oor run. Hence no further description of the deceleration of the car will be given.

This assumed operation illustrates how the 'system acts in making a more than one-floor run.

This control system is designed to give a quick leveling action without releveling in about 70% of the operations. All motoring loads `will come to the oor quickly and without pause or overrun. Overhauling loads from nearly empty car up to approximately 70% load down will come in likewise. Empty car up and load down will usually overshoot the cor about one-half inch and relevel quickly. Full load down will overshoot the oor about three inches and relevel, provided in each case that the starting switch is centered in time to permit retardation to high leveling speed before entering the leveling zone.

The action of coming into the oor quickly is obtained by making the high leveling speed (3P closed) and the retardation after entering the leveling zone (the inductor plate zone) just sumcent to cause the car to stop level with the floor. The speeds to which the car is decelerated by the closing of the relays iP or 2P should be sulcient that, if the car overtravels the loor 7 inches or la inches or more, it will return at a speed sumcient to prevent a pause coming to the oor and to prevent overtravel of the floor. With these settings the car will never corne short of the oor but will stop level or run past it. The operation of returning to the floor has been observed to be much faster than stopping short (pausing) and then continuing to the iloor.

The system is particularly suited to an elevator with a car having a high running speed of approximately 350 feet per minute, and in which the retention of the resistors r6 and r1 in the pattern circuit by the opening of contacts GRI will reduce the high-running speed of the car to a high decelerating speed of approximately 200 feet per minute as it moves the inductor relay down to the inductor plate zone. Then as the car enters the inductor plate zone, the high speed decelerating relay 3P, the intermediate speed relay 2P, and the low speed relay IP are deenergized in quick succession. This rapid weakening of the regulator pattern iield combined with the strengthening of the dilerential eld produces a rapid retardation which tests show will stop any car load except the heaviest loads, level with the oor without overrun, underrun in any zone of approach at a regulated constant speed. It is believed that this action is producedv through the slightly unstable characteristic of the regulator due to its abnormally strengthened diierential eld acting to produce a proportionately stronger retardation for a loaded car than for a balanced car. Y

In operating 'this system, some variation in operation has been found traceable to changes in temperature. When the motor gets considerably hotter than would be expected in normal operation, the car will overtravel approximately an inch and then return, where a cooler motor would cause a level stop without overtravel.' It is anticipated that cold conditions, such as may occur in some penthouses in the winter, will cause the car to stop short of every stop while the temperature remains low.

I have provided a remedy for this by including a resistor in circuit with one of the eld windings of the regulator and means for short-circuiting that resistor to suit the Weather conditions. The resistor may be included in either the pattern eld winding circuit or in the loop circuit 22 connecting the self-exciting iield winding RCF and the generator eld vwinding GF. In this instance I have included a resistor rl in the loop circuit 22 and have provided for its control by means of a push button 3| which may be located in the elevator car C for operation by the car attendant. I have also provided a thermostat 34 which may be mounted on the frame of the regulator and connected to so control the resistor rl in accordance with temperature conditions as to secure the same degree of operation under various conditions of temperature. The thermostat may be adjusted to short out a few ohms of resistance to correct for the change in temperature when the frame heats up a predetermined amount. In tests, it has been found that three ohms are about the correct amount to short out. Normally, I supply around eight ohms `cold for the adjustment of the loop when the apparatus is installed and placed in operation.

The circuits for the system illustrated and described have purposely been shown in the sim- 4plest manner, omitting for simplicity the motor field control, the discharge rectoxes around the leveling switch coils and other places, and the safety circuit and door operating circuits, as they may be readily supplied by any .one skilled m the art. The time relays are indicated merely by cha e resistances. disAlthlogugh I have illustrated and described only one specific embodiment of my invention, it is 75 to be understood that modifications thereof and changes therein may be made without departing from the spirit and scope of the invention.

I claim as my invention:

l. In a control system for an elevator car serving a plurality of landing iioors, a power generator provided with an armature and a eld Winding, a hoisting motor connected in a loop circuit with and controlled by said armature for operating the car; a regulator for energizing and controlling the field winding of the power generator, said regulator having iield windings including a differential held winding; a switch, a control device, means responsive to a temporary operation of the switch for operating the control device, means responsive to operation of the control device for starting and running the car, means for controlling the regulator to decelerate the hoisting motor, a timing device for maintaining the control device in its operated condition for a predetermined time after it is operated and then causing it to be restored. to its unoperated condition, means responsive to the return of the control device 'to onoperated condition for rendering the accelerating means effective to cause the hoisting motor to decelerate the car as it approachs the next i'ioor, and means responsive to operationof decelerating means for strengthening the difierential iield to render the deceleration more eifective.

2. In a control system for an elevator oar serving a plurality of landing floors, a power generator provided with an armature and a field winding, a hoisting motor connected in a loop circuit with and controlled by said armature ior operating the car; a regulator for energizing and controlling the field winding oi the power generator, said regulating generator including a diferential field winding; a switch, a control device, means responsive to a temporary operation of the switch for operating the control device,

means responsive to operation of the control device for starting and running the car, means for controlling the regulator to decelerate the hoisting motor, a timing device for maintaining the control device in its operated condition for a predetermined period of time after it is operated and then causing it to be restored to its unoperated condition, means responsive to restoration of the control device to its unoperated ccndition for rendering the decelerating means effective to cause the hoisting motor to decelerate the car as it approaches the next floor, means responsive to operation 4or' the decelerating means for strengthening the differential eld of the regulator to render the deceleration more elective, a releveling means for controlling the motor to relevel the car, and a time delay means responsive to the restoration of the control device to its unoperated condition for preventing the releveling means from reversing the connections of the regulator for a predetermined time.

3. In an elevator system for operating a car serving a plurality of landing floors, a switch, a car starting and running means, a control device responsive to a temporary operation of the switch for operating the car starting and running means, means for causing the car to decelerate and stop at a iioor, and a time delay device responsiveto operation of the car starting and running means for maintaining the control device in operation for a predetermined period of time after it is operated and for then rendering time mechanism for maintaining the accelerating means in operation for a predetermined time period and at the end of said time period for rendering said accelerating means ineffective so that the car retards in speed; means responsive to the approach of the carto a iioor for actuating said stopping means; whereby the car will, in response to a temporary actuation of said car switch, start, accelerate to a high speed, retard to a low speed, and stop accurately at a floor adjacent to the one from which the car started. v

5. A variable voltage system of control cornprising a power generator provided with an armature and a field winding and a motor connected in a loop circuit with said armature; a regulating generator for energizing the field winding of the power generator, said regulating generator having an armature, a series field winding, a differential field winding, a self-exciting field winding, and a pattern field winding; control means for connectingthe pattern field winding to a source of energy to operate the motor at its high running speed, decelerating means for controlling the regulator to decelerate the motor, and means responsive to operation of the decelerating means for strengthening the difierential field of the regulator to render the deceleration more effective.

6. A variable voltage system .of control comprising a power generator provided with an armature and a field winding and a motor connected in a loop circuit with said armature; a

armature and a eld winding and a motor connected in a loop circuit with said armature; a regulating generator for energizing the field Winding of the power generator, said regulating generator having an armature, a series field winding, a. differential field winding, a self-exciting ielri winding, and a pattern field winding; decelerating means for controlling the regulator to decelerate the motor, a resistor disposed in series with the differential field winding, means responsive to operation of the decelerating means for shortcircuiting a portion of the resistor to strengthen the differential field to render the deceleration more eiective, a resistor disposed in series with the series field winding. and means I responsive to operation of the decelerating means' regulating generator for energizing the eld winding of the power generator, said regulating generator having an armature, a series field winding, a differential field winding, a self-exciting eld winding, and a pattern field winding; control means for connecting the pattern field winding to a source of energy to operate the motor at its high running speed, decelerating means for controlling the regulator to decelerate the motor, and means responsive to operation of the decelerating means for weakening the pattern field winding in rapid successive steps and strengthening the differential field winding to produce a rapid retardation of the motor.

7. A variable voltage system of control comprising a power generator provided with an armature and a field winding and a, motor connected in a loop circuit with said armature; a regulating generator for energizing the field winding of the power generator, said regulating generator having an armature, a series field winding, a differential eld winding, a self-exciting field winding, and a pattern field winding; decelerating means for controlling the regulator to decelerate the motor, a resistor disposed in series with the differential field winding, and means responsive to operation of the decelerating means for short-circuiting a portion of the resistor to strengthen the differential field to render the deceleration more effective.

8. A variable voltage system of control comfor short-circuiting a portion of the resistor in the series iield winding for strengthening the series field to )reep the regulator regulation at.

9. A variable voltage system of control comprising a power generator provided with an armature and a field winding and a motor connected is a loop circuit with said armature; a. regulating generator for energizing the field winding of the power generator, said regulating generator having an armature, a, series field winding, a differential field winding, a self-exciting eld winding, and a pattern field winding; decelerating means for controlling the regulator to decelerate the motor, a resistor disposed in series with the differential field winding, means responsive to operation of the decelerating means for short-circuiting a portion of the resistor to strengthen the differential field to render the deceleration more e'ective, means for controlling the regulator to stop the motor, and means responsive to operation of the stopping means for short-circuiting an additional portion of the resistor to strengthen the differential field still further for field killing purposes.

10. A variable voltage system of control comprising a power generator provided with an armature and a field winding and a motor connected in a loop circuit with said armature; a regulating generator for energizing the field winding of the power generator, said regulating generator having an armature, a series field winding, a differential field winding, a self-exciting eld winding, and a pattern field winding; decelerating means for controlling the regulator to decelerate the motor, and means responsive to operation of the decelerating means for strengthening the differential field of the regu- `'lator to render the deceleration more effective and for strengthening the series field when the caris in the decelerating zone for keeping the regulator regulation fiat.

1l. A variable voltage system of control comprising a power generator provided with an armature and a field winding and a motor connected in a loop circuit with said armature; a regulating generator for energizing the eld winding of the power generator, said regulating generator having an armature, a series eld winding, a differential field winding, a self-exciting iield winding, and a pattern eld winding; decelerating means for controlling the regulator to decelerate the motor, means responsive to operation of the decelerating means for strengthening the dii'erential field o the regulator to render the deceleration more effective and for strengthening the series field when the car is in the decelerating zone for keeping the regulator regulation fiat. means for stopping the motor,

and means responsive to operation of the stopping means for further strengthening the diiferential eld for neld killing purposes.

12. A variable voltage system of control comprising a power generator provided with an armature and a iield winding and a motor connected in a loop circuit with said armature; a regulating generator for energizing the iield winding of the power generator, said regulating generator having an armature, a series eld winding, a differential field winding, a self-exciting iield winding, and a pattern iield winding; control means for connecting the pattern field winding to a source of energy to operate the motor at its high running speed, decelerating means i'or controlling the regulator to decelerate the motor, means responsive to operation of the decelerating means for strengthening the differential field of the regulator to render the deceleration more effective, and means for decreasing the resistance in a field winding of the regulator for compensating for a low temperature condition of the apparatus.

13. A variable voltage system of control comprising a power generator provided with an armature -and a field winding and a motor connected in a loop circuit with said armature; a

hregulating generator for energizing the field winding of the power generator, said regulating generator having an armature, a series field winding, a diierential eld winding, a self-exciting field winding, and a pattern field winding;

control means for connecting the pattern ileld winding to a source oi energy to operate the motor at its high running speed, decelerating means for controlling the regulator to decelerate the motor, means responsive to operation of the decelerating means for strengthening the differential field of the regulator to render the deceleration more effective, and a thermostat associated with the regulator for decreasing the resistance in a iield winding circuit for compensating for a low temperature condition of the apparatus.

14. A variable voltage system of control comprising a power generator provided with an armature and a iield winding and a motor connected in a loop circuit with said armature; a regulating generator for energizing the field winding of the power generator, said` regulating generator having an armature, a series iield winding, a difierential field winding, a self-exciting iield winding, and a pattern eld winding; control means for connecting the pattern eld winding to a source of energy to operate the motor at its high running speed, decelerating means for controlling the regulator to decelerate the motor, means responsive to operation of the decelerating means for strengthening the differential field of the regulator to render the deceleration more eifective, and a manually operated switch for decreasing the resistance ina field winding circuit o! the regulator to compensate for a low temperature condition of the apparatus. l i

WILLIAM F. EAMES.

Images