US2000703A - Elevator control system - Google Patents

Description

y 1935- P. c. KEIPER 2,000,703

ELEVATOR CONTROL SYSTEM Filed April 27, 1952 2 Sheets- Sheet 1 WITNESS S: I INVENTOR Phi/Zip (Z Kez'per'. Wu

ATT

May 1935- v P. c. KEIPER 2,000,703

ELEVATOR CONTROL SYSTEM Filed April 27, 1952 -2 Sheets-Sheet 2 I I. [WM y Ill .11

INVENTOR WITNESS s; W I P/zz/zzp a izfezper. 0

. BY A firmv Patented May 7, 1935 UNITED STATES nmvsron coN'rnoL SYSTEM Phillip C. Kelper, Chicago, Ill., assignor to Westinghouse Elevator Company, a corporation of Illinois Application April 27, 1932, Serial No. 607,705

46 Claims.

My invention relates to electric elevator systems, and more particularly to systems in which switching devices mounted partly on the elevator car and partly in the elevator hatchway are employed to commutate various circuits in accordance with the position of the car in the hatchway.

In systems of this general character, which are well known in the prior art, the usual arrangement comprises a plurality of switching devices carried upon the elevator car, one for each circuit or group of circuits to be commutated, and disposed to cooperate with devices spaced at predetermined intervals in the hatchway. The arrangement has been such, however, that each of the switches must be mounted in a separate vertical plane, in order to prevent interference, and to obtain the proper sequence of operation of the switches. l

In the more complicated elevator systems, 0 which require commutation of a substantial number of such circuits, the switches require a considerable amount of space on top of the elevator car, and the mounting thereof in separate vertical planes becomes a serious problem.

In the majority of elevator systems, the rails which guide the movements of the elevatorcar are mounted on two sides of the elevator hatchway for cooperation with guide shoes resiliently mounted on the elevator car. Due to the fact that the spacing between the rails cannot be maintained constant throughout the hatchway, it is necessary to construct the guide shoes to permit a certain amount of relative movement between them and the car. This limited movement is ordinarily of the order of from threefourths of an inch to one inch. It is also impossible to keep the load in the elevator car evenly distributed, and it frequently happens, therefore, depending upon the distribution of load in the car, that the car will be moved to one side of the hatchway or the other. It therefore becomes impractical to mount control apparatus on the sides of the elevator car which are parallel to the plane of such lateral movement.

h A portion of the remaining two sides of the elevator car, which are available for the mounting of hatchway switching devices is taken up by other apparatus which must be mounted upon the elevator car. This additional apparatus comprises, in general, the mechanism for driving the governor cable, a junction box to receive the hanging cables which carry conductors which connect the electrical apparatus on the car with the main controller for the elevator, the limit switch mechanisms, the cross head beam on whichthe guide shoes are mounted, etc. It is usually found that the only space available for the mounting of the hatchway switching devices is limited to that on one side of the car, between the cross head beam and the side of the car, and with relatively small 5 cars, it becomes very difficult to locate the required number of: switches in this limited space.

The present invention comprises an arrangement of apparatus whereby more than one hatchway switch may be mounted in a single vertical plane, without permitting interference between the several switches in the same plane, and without disturbing the proper sequence of operation of the several switches. In a preferred embodiment of the present invention, to be hereinafter more fully described, this objective is effected partly by using hatchway switching devices having different operating characteristics, whereby a particular switch, although brought adjacent the hatchway members associated with other switches, is not caused to operate until brought adjacent the hatchway member associated with the particular switch; and partly by so arranging the circuits that operation of certain of the devices is dependent upon previous operation of others of the devices.

In the'prior'elevator art, a number of types of switching devices comprising a part carried on the car and apart mounted on the hatchway, have been used to commutate various control circuits in accordance with the position of the car in the hatchway. These include devices which are mechanically operated, devices which are inductively operated, devices which are magnetlcally operated, and devices which are oper- 30 ated through the cooperation between a source of light and a light sensitive device. Arrangements of the latter three types, which are preferable in highspeed systems, due to quietness of operation and minimized danger of breakage, are illustrated and described respectively in patents to Claytor, granted May 16, 1933; Williams et al. 1,902,602, granted March 21, 1933; and Mattingly, 1,865,937, granted July 5, 1932, all of which are assigned to the Westinghouse Electric and Mauui'acturing Company.

In the practice of the present invention, I prefer to use switching devices of the magnetically operated type and of the light sensitive type. As described in the Williams et al. Mattingly patents, above identified, the magnetically operated devices comprise a switch having a portion of the magnetic circuit thereof carried upon the elevator car and the remaining portion thereof mounted in the hatchway, while the light sensitive arrangement comprises a source of light and a light sensitive device normally disposed to be illuminated by the light, both carried by the elevator car, and an opaque shield mounted in the hatchway to intercept the light.

The opaque shield may, of course, be made of a non-magnetic material. It is seen, therefore, that although the light sensitive unit and the magnetic unit are mounted in the same vertical plane, the opaque shield is effective to cause operation of only the light sensitive unit. The magnetizable member may, of course, be in the form of a preforated plate, which, while effective to operate the magnetic device would be inefiective to interrupt sufficient of the light from the light source to operate the light sensitive device. In the illustrated embodiment of the present invention, however, the usual solid magnetizable plate is employed, and independent means are provided to render the interruption of the light inefiective to actuate the apparatus controlled by the light sensitive device.

A representative use to which switches of the character in question may be put is that of controlling the deceleration, stopping, and, in certain cases, the leveling, of the elevator car, and in the illustrated embodiment of the present invention, the hatchway switching devices are used for these purposes.

The present invention, inaddition to providing an arrangement to reduce the space requirements of the hatchway switching devices also comprises a novel leveling arrangement. In the usual prior art leveling arrangement an up-leveling switch and a down-leveling switch are mounted upon the elevator car for cooperation, respectively, with an up-leveling cam and a down-leveling cam, mounted in the hatchway in such positions that when the elevator car is level with the floor landing, both switches are out of engagement with the respective cams. In these systems, if the elevator car stops at, or drifts to, a point other than level with the landing, one of the switches is brought into engagement with the associated cam and is, therefore, actuated to complete circuits to cause the car to move to the landing. In these systems, since the leveling circuits are only completed when one of the switches is in engagement with the associated cam, the leveling zone is determined by the length of the cams. Accordingly, if the car stops or drifts to a point beyond the limits of the cams, no leveling movement takes place.

According to the present invention, however, the arrangement is such that the leveling zone is independent of the dimensions of the hatchway device. Accordingly, in the present arrangement, although relatively short devices may be mounted in the hatchway, the leveling zone is unlimited.

In addition to requiring a relatively simple circuit arrangement whereby the above leveling feature may be attained, a light sensitive arrangement having many of the features of the arrangement disclosed in the above identified Mattingly patent is particularly advantageous in controlling the leveling operations, in view of the extreme accuracy of. operation of these devices. Accordingly, in the illustrated embodiment of my invention, light sensitive devices are used to control the leveling circuits.

As noted above, the leveling arrangement is such that the length of the leveling zone is in no way determined by the length of the shields, mounted adjacent the floor level. In the illustrated embodiment of the present invention, however, shields of from six to eight inches in length are used, since the present invention also comprises a circuit arrangement whereby under certain conditions of operation, one of the light sensitive devices controls a step of deceleration, from high leveling speed to landing speed, when one limit of the shield is reached, and, under other conditions controls the stopping of the car, when the other limit of the shield is reached. In accordance with this arrangement, although two leveling speeds are provided, for each direction of travel, a total of two light sensitive units is efiective to control all four operations. By arranging each device to control more than one separate control function, it will be observed that less apparatus is required, thereby further reducing the space requirements of the hatchway switching devices without reducing the number of steps of deceleration.

It is accordingly an object of the present in- L vention to provide an elevator system in which a plurality of independent hatchway switching devices may be mounted in the same vertical plane without producing interference or disturbing the proper sequence of operation of the switches.

It is a further object of the present invention to provide such an arrangement in which hatchway switches having different operating characteristics are employed whereby the cooperating hatchway members associated with other switches, although brought adjacent a particular switch, are ineffective to actuate that switch.

It is a further object of the present invention to provide such a system in which magnetically operated devices and light sensitive devices are arranged to selectively effect various control operations.

It is a further object of the present invention to provide an elevator system in which the leveling zone of the elevator is independent of the dimensions of the devices, mounted in the hatchway, which initiate the leveling operations.

A further object of the present invention is to provide a leveling system of the above type in which light sensitive devices are used to control the leveling operations.

It is a further object of the present invention to provide an elevator system in which a single hatchway switching device is efiective to control a plurality of separate switching operations.

More particularly stated, it is a further object of the present invention to provide a system of the above character in which a single hatchway switching device is effective under certain conditions, to control a stopping operation, and is effective under other conditions, to control a step of deceleration.

Other objects and advantages of the present invention will be apparent in the course of the following detailed description thereof.

Referring to the drawings,

Figure 1 is a schematic diagram of a control system embodying the present invention,

Fig. 2 is a view in perspective, showing the relative positions and certain details of the magnetically operated, and light sensitive operated, switching devices used in the practice of the present invention, and

Fig. 3 is a view showing the relative positions, on the car, of the hatchway switching devices, and the members mounted in the hatchway for cooperation therewith, respectively.

In Fig. l, a motor M, having a field winding MI, is connected to receive power from a generator G in accordance with the Ward Leonard or variable-voltage principle. Motor M is directly connected to a shaft which carries a brake-drum B, and a cable-drum D, over which the hoisting cables Ca pass. The elevator car C and counterweights Cw are attached to the opposite ends of cables Ca, in the usual manner.

Generator G, which is continuously driven at substantially constant speed by any suitable means (not shown), is provided with a separately excited field winding G1, a. demagnetizing field winding GA and a series field winding GS).

Winding GSf is directly connected in the armature circuit of motor M and generator G and is designed to raise or lower the voltage of generator G, depending upon the magnitude and character of the load exchanged between the motor M and generator G, to render the speed of motor M substantially independent of load.

Winding GAf is arranged for connection, through a main switch 5, across the armature terminals of generator G, at the expiration of the slow down operation, and is wound to produce a magnetomotive force in opposition to the residual magnetism of that machine, and therefore, to reduce the voltage thereof quickly to substantially zero.

Winding Gf, which controls the direction and speed of operation of motor M, is arranged for high-levellng-speed relay 8 are controlled by accelerating relay ll. Relay II, in turn, is subject to joint control by car-switch contact members HS, and leveling relays UL and DL.

Speed-limiting relay l3, current-relay l2, and anti-plugging relay H are employed in connection with the late-stop feature of the present invention.

Auxiliary relay I5 is controlled by intermediatespeed relay 9 and main switch 5, and is arranged to delay the operation of high-speed relay I0, during acceleration.

Relay I6 is included in the door safety circuit, and controls a plurality of circuits including the high speed circuits and certain of the leveling circuits.

- In accordance with the illustrated arrangement, the starting and acceleration to full speed of motor M is under the control of car-switch contact members U, D and HS. Referring to Fig. 3, these contact members are shown as carried upon the elevator car C for control by the usual rotatable car switch Cs. In the conventional manner, clockwise rotation of switch Cs is effective to sequentially close contact members U and contact members HS, while counter-clockwise rotation of switch Cs is effective to sequentially close contact members D and contact members HS.

As discussed hereinbefore, the deceleration and leveling of the elevator car is controlled by means of switching devices carried partly upon the elevator car. In Fig. 1, these devices are illustrated schematically as switches 3L, 2L and a combination of apparatus shown at the bottom of the figure and identified generally as IL. As indicated hereinbefore, switches 3L and 2L are both of the magnetically operated type, while the apparatus identified as IL is of the light sensitive type.

Referring to Fig. 2, and as described in the Williams et a1. application, identified hereinbefore switch 2L, of which switch 3L is a duplicate, comprises an electro-responsive or energizable coil 2La, the magnetic circuit of which includes the end plates 2Lb and 2L0, a back plate 2Ld and a plurality of sets of fingers ZLe, 2Lj ZLg and .ZLh. The respective contact fingers 2Le, 2Lf, 2L9 and 2Lh are mounted for a limited amount of rotation about pins 2Li. As illustrated, contact fingers 2L6 normally occupy positions in which a set of contact members ZUL controlled thereby is maintained in the closed position. Contact fingers 2L) are similarly arranged to normally maintain a pair of contact members 2DL in the closed position, although the latter contact members are not visible in Fig. 2. Contact fingers 2Lg and 2Lh are similarly provided, although the contact members associated with these fingers are not utilized in the system shown in Fig. 1.

The arrangement is such that, although coil 2La, is energized, the several pairs of contact members are subjected to no magnetic force tending to cause rotation thereof about the respective pins 2Li to thereby open the contact members associated therewith. If, however, a magnetizable plate, as 2U, is moved into the slot between the extreme ends of fingers 2Le, the flux density is substantially increased, and direction of the magnetic field between these fingers and the plate assumes such a direction as to rotate them about the pins 2L2 and thereby open the contact members ZUL. Similarly, if a magnetizable plate 2D is moved into the slot between the fingers 2Lf, these fingers are actuated to open the contact members 2DL. As will be obvious, the magnetic force on the contact fingers is a maximum when a plate occupies a position opposite the slots of both ends of the switch, and the actuation of the contact members normally occurs when plate and switch occupy such relative positions.

Referring to Fig. 3, switches 2L and 3L are shown as mounted on the top of elevator car C, which is movable past floor levels a and b. Magnetizable iron plates 3Ua and 3Ub are mounted in the hatchway in positions to cooperate with switch 3L and actuate contact members 3UL thereof, and thereby interrupt the high speed circuits of the elevator car as the car approaches floors a and b, respectively, in the up direction.

A similar set of plates 3Da and 3Db is mounted in the hatchway in positions to pass between the fingers of switch 3L which control contact members 3DL and thereby interrupt the high speed circuits as the car approaches floors a and b, respectively, in the downward directions.

Similarly, a set of plates ZUa, 2Ub, and 2Da and 2131) are provided to cooperate with switch 2L, to actuate contact members 2UL and ZDL thereof, respectively, to interrupt the intermediate speed circuits of the elevator car during upward and downward travel thereof respectively.

In practice, the plates are normally from ten to twelve inches in length, or slightly longer than the vertical dimension of the switches.

As will be obvious from Fig. 3, the positioning of plates 3Ua, 3Da, 2Ua and 2Da, etc. with respect to the floor levels a and 1) depends upon the maximum speed of the elevator car. In a representative system arranged for operation at approximately 600 feet per minute, the series of plates arranged for cooperation with switch 3L are so mounted as to actuate the associated contact members when the elevator car is at a distance of from ten to eleven feet from a selected floor; the series of plates associated with switch 2L are disposed to actuate the associated contact members when the elevator car is at a distance of from five to six feet from the associated floor.

The light sensitive apparatus IL comprises, in general, two electro-responsive or light sensitive cells, associated, respectively, with the up and down directions of travel, and cooperating optical elements whereby the condition of illumination of the cells may be controlled in accordance with the relative positions of the several elements. In the illustrated embodiment, the arrangement of circuits and apparatus is such that the cells are preferably in a current conducting condition except when the car is substantially level with a floor landing. Accordingly, the associated optical elements comprise a source of light normally disposed to illuminate the cells, and cooperating members disposed to effect the darkening of the associated cells when the car reaches a point substantially level with the landing.

Returning to Fig. 2, the device IL is shown as comprising a source of light X, a light sensitive cell UK and a light sensitive cell DX, all of which are mounted, in spaced relation, in the same horizontal plane. The source of light X is provided with a casing Xa having small apertures Xb on opposite sides thereof through which a restricted beam of light is passed. Similarly, light sensitive cells UK and BK are provided with casings UXa. and DXa which are provided respectively with longitudinal apertures UXZJ and DXb, which permit the restricted beam of light from the source X to fall upon the associated light sensitive cells. The respective casings are attached to the main casing iLa in any suitable manner.

The remaining apparatus associated with the light sensitive cells UX and DX is mounted within the main casing ILa, and comprises two am plifying tubes UA and DA, a transformer T, and a condenser C. The electrical characteristics and relationship of the several elements of the device lL will be described in connection with Fig. l, in a later paragraph.

The switching devices IL and 2L are both connected directly to the angle bracket F, and as shown in Fig. 3, the entire assembly is mounted directly on the top of the elevator car 0.

As shown in both Figs. 2 and 3, the relative positioning of switch devices IL and 2L is such that the slot between contact fingers 2L6 is in vertical alignment with the space between casings UXa and Xe, and that the slot between contact fingers 2L is in vertical alignment with the space between the casing Xa and casing DXa.

The actuating means associated with switching evice IL comprises a pair of opaque shields of non-magnetic material, associated with each floor. Referring again to Fig. 3 a series of plates His and lDa are mounted in the hatchway to control switching device L when the car is adjacent fioor and a similar set, IUb and IDb, is mounted in the hatchway to control switching device IL when the car is adjacent floor I). The relative positioning of the plates is such that, if car C is exactly level with a floor landing, light-sensitive device IL occupies a position in which the beams of light between the source X and cells UK and DX are interrupted, respectively, by shields IUa and IDa.

When the car is moving upwardly, in the region just below fioor a, shield IDa interrupts the light falling on light sensitive cell DX, thereby reducing the speed from the high-leveling value to the landing value; as the car approaches the floor more closely, shield IUa interrupts the light falling on cell UX, thereby stopping the car. During downward travel, shield IUa controls the deceleration from high-leveling speed to landing speed and shield IDa controls the stopping of the car.

In a typical system, the high-leveling speed may be of the order of from 50 to 60 feet per minute, in which case the high leveling speed circuits are interrupted when the car is from six to seven inches away from the floor; the landing speed may be of the order of from 15 to 25 feet per minute, depending upon the landing-accuracy required, in which case the stopping circuits are interrupted when the car is from one-quarter to one-half an inch away from the floor.

Accordingly, shield IUa extends from onequarter to one-half an inch below, and from six to seven inches above the point occupied by the center line of switch IL when the car is level with the floor; shield IDa extends from one-quarter to one-half an inch above and from six to seven inches below the corresponding point, The shields associated with the other floors are similarly arranged.

Returning to Fig. 1, the light-sensitive cells UK and BK, are arranged to control leveling re- 3 lays UL and DL respectively, through the intermediary of amplifiers UA and DA, the respective light-sensitive cells being connected in the grid circuits of the associated amplifiers. The lightsensitive cells are preferably, though not necessarily, of the two-element evacuated type comprisinga photo-sensitive cathode c and an anode a. As is well known in the art, the resistance of these cells is substantially inversely proportional, throughout a predetermined range, to the amount of light falling upon the photo-sensitive cathode. The amplifiers UA and DA are preferably, although not necessarily, of the threeelement vacuum type comprising filaments f, plates p and grids g.

The coils of leveling relays UL and DL are connected, respectively, in the plate circuits of amplifiers UA and DA across a source of alter nating current, represented as the secondary winding TI of a transformer T. The light-sensitive cells UX and DX are connected respectively in the grid circuits of amplifiers UA and DA, the grids being connected, respectively, in series with condensers c3 and 04, to a point of lower potential than the cathodes of the associated amplifiers.

The filaments of amplifiers UA and DA, and the source of light X are supplied with current from secondary winding T3 of transformer T. Condensers cl and 02 are connected in parallel, respectively, with the coils of leveling relays UL and DL, and serve to smooth out current changes, in the usual manner.

In the illustrated embodiment, the circuit arrangement is such that when the light-sensitive cells UK and DX are darkened, the negative bias of grids g is sufficient to reduce the plate current of the associated amplifiers to substantially zero. Accordingly, under these conditions, the coils of leveling relaJ/s UL and DL are deenergisedand theserelaysoocupythe-illustra'ted positions. If, however, a beam of light is permitted to fall upon the cathode of either of the cells UK and BK, the resistance of that cell is decreased and the potential of the associated grid 9 is raised sumciently to increase the plate current of the associated amplifier UAor DA to the value required to actuate the associated relay UL or DL. since the light beams may be controlled with considerable accuracy, by limiting apertures UXb or Dxb, or through use of lenses, and since cells UK and DK and amplifiers UA and DA respond almost instantaneously, it is obvious that light sensitive device IL is efiective to commutate the leveling circuits with corresponding accuracy.

As previously described, it is desirable, under certain conditions, torender relays UL and DL independent of the condition of light-sensitive cells UK and BK, respectively. 'Toaccomplish this, independent means to maintain suflicient voltage across these relays to either actuate them or to maintain them actuated may be'provided. In the illustrated embodiment, theindependent means comprises sequence relay II, contact members a of which are maintained closed through-' out the upper portion or the speed range of the elevator system and occupy the open position throtmhout the lower portion of the speed range. Contact members a. of sequence relay I'I control the point at which the grid circuits of ampliflers UA and DA are connected to potentiometer resistor R6, associated with secondary winding T2 of transformer T. Closure of contact members a shunts an adjustable portion of resistor'RG and is effective to raise the potentials of'grids a by an amount suilicient to increase the plate currents of the associated amplifiers to the value required to actuate the associated leveling relays UL and DL.'

The circuits controlled by the contact members of the leveling relays UL and DL for efiecting the starting, operating and stopping of the hoisting motor as a means to move the car are called the leveling circuits or leveling connections. The circuits controlled by the up leveling relay UL are the up leveling connections. The circuits controlled by the down leveling relay DL are the down leveling connections.

The light sensitive cells UK and DK and the cooperating opaque plates IUa, lDa, IUb and IDb comprise the leveling mechanism which, through the relays UL and DL control'the leveling circuits or leveling connections, the cell UK and the plates IUa and W1) comprising the elements of the up leveling mechanism, and the cell DX and the plates IDs and IDb comprising the elements of the down leveling The several features oi. the present invention may best be understood from a detailed analysis of several operating cycles of the system.

Returning to Fig. l, the system may be placed in condition for operation by energizing the.driv-' ing motor (not shown) to thereby bring generator G up to running speed, by closing manual switch K to connect line conductor MI and M2 to a source of direct current M, and by closing switch KI to thereby connect the primary winding T4 of transformer T to a source of alternating current AC.

Bringing generator G up to full speed is without effect, since winding G1 is deenergiaed and the voltage of generator G1 is accordingly zero. Closure of switch K completes the circuit for the field winding M! of motor M, thereby preparing this machine for operation upon the application of voltage to the armature thereof. Closure of switch KI applies voltage to the amplifiers UA and DA, and to the cells UK and DX. Relays UL and DL are not actuated, however, since contact members a of relay I1 are open, and, as illustrated in Fig. 3, the beam of light from source X are interrupted by plates IUa and IDa, respectively.

If all of the hatchway doors and the car gate are closed, door relay I6 is actuated to close contact members a. and b.

Assuming that it is desired to move elevator car C upwardly, car switch Cs (Fig. 3) may be moved in a clockwise direction to close contact members Uand HS. In practice, switch Cs is moved directly to the extreme position. For the purposes of this description, however, the opera-- tions caused by closure of contact members U and HS will be considered separately. Upon closure of contact members U, a circuit is completed for the coil of up-direction relay 6, which extends from line conductor MI, the coil of relay- 6, contact members U and contact members "a of door-relay I6 to line conductor M2. Upon completion of this circuit, relay 6 is actuated to close contact members a, b and c and to open contact members d.

Closure of contact members a of relay 6 prepares a-circuit for the coil'of accelerating relay II, which circuit is controlled by the car switch contact members HS. Closure at contact members c prepares a holding circuit for the coil of relay 6. Opening of contact members d is without immediate effect.

Closure of" contact members b of relay 6 completes acircuit for the coils of main switch 5 and reversing switches I and 3. I This circuit extends from line conductor MI through the coil of switch 5, normally closed contact members a of antiplugging relay I4, the coils of reversing switches I and 3, and contact members b of relay 6 to line conductor M2. Upon completion of this circuit, switch 5 is actuated to open contact members a and to close contact members b, c, d, e and f, reversing switch I is actuated to close contact members a, b, d, e and ,f; and to open contact members 0'; reversing switch 3 is actuated to close contact members a.

The opening of contact members a of switch 5 interrupts the circuit of the demagnetizing winding GAj which operation is without eifect during acceleration. Closure of contact members b of switch lprepares a circuit'for the release coil Br of the electromagnetic brake. Closure of contact members 0 of switch 5 is without efiect, during acceleration. Closure ofcontact members d and f of switch 5 completes,.respectively, the circuit for the windings of slow- down switches 3L and 2L, which operations are without effect, since these switches are not opposite any of the magnetizable plates associated therewith. Closure of contact members e of switch 5 completes a circuit for the coil of auxiliary accelerating relay I5, which is thereby actuated to open contact members a thereof.

Closure of contact members a of switches I and 3 completes a circuit for the separately excited field winding Gf of generator G, which circuit extends from line conductor MI through contact members a of switch I, through field windingGf and. resistor R4 in parallel, contact members a of switch 3 and thence to line conductor M2 through accelerating resistors RI, R2 andR3. Completion of the above circuit also energizes the winding of an auxiliary relay II, the function of which will be described in connection with an emergency stopping operation.

Upon completion of the above circuit for winding Gf, sufficient magnetomotive force is impressed on the field structure of generator G to cause this machine to generate a voltage corresponding to the lowest or landing speed of elevator car C. Accordingly, upon release of the electromagnetic brake B, the coil Br of which is energized in response to closure of contact members b of switch I, the elevator car is caused to start upwardly and accelerate to-the landingspeed.

The opening of contact members 0 of switch I is without effect during acceleration. Closure of contact members d, e and ,f of switch I prepares circuits for the coils of high-speed relay I0, intermediate-speed relay 9, and high-leveling-speed relay 8, respectively.

Assuming that it is desired to operate the car at high speed and that car switch contact members HS are closed, a circuit is completed for the coil of accelerating relay II, which circuit extends from line conductor MI through the coil of relay II, contact members a of up-direction relay 6, car switch contact members HS and through contact members a. of door-relay I6 to line conductor M2.

Upon completion of this circuit, relay I I is actuated to close contact members a, b, d and f and to open contact members 0 and e. Closure of contact members a is without effect, since the circuit for speed limiting relay I3 is interrupted elsewhere. The opening of contact members 0 and c has no effect other than to interrupt the previously traced circuits for the coils of slowdown switches 3L and IL.

Closure-of contact member .1 completes a circuit for the coil of high-lcveling-speed relay 8, which is thereby actuated to short circuit resistor RI, increasing the current in the field winding Gf, which results in a corresponding increase in the voltage of generator G and the acceleration of motor M to the high leveling speed.

Closiu'e of contact members d of relay I I causes completion of circuits for the coils of intermediate-speed relay 9 and sequence relay II, which circuit extends from line conductor MI, through normally closed contact members of relay I3, contact members e of reversing switch I, contact members 2UL of slow-down switch 2L, contact members it of accelerating relay II, in parallel through the coils of relays 9 and I1, and through contact members b of door relay I6 to line conductor M2. Closure of contact members b of accelerating relay I I prepares a circuit for the coil of high-speed relay I0,-which circuit is subject, however, to the now open contact members of auxiliary relay I5. 7

Upon being energized, sequence relay I1 is actuated to close contact members a, thereby short circuiting an adjustable portion of resistor R6. As previously described, this operation results in reducing the negative bias of the grid g of amplifiers UA and DA by an amount suflicient to increase the plate currents of these amplifiers to the values required to actuate leveling relays UL and DL, respectively. Accordingly, these relays are actuated to close, respectively, contact members a and b and to open contact membersc and d. Closure of contact members a of relays DL and UL completes a maintaining circuit for the coil of high-leveling-speed relay 8, which is independent of accelerating relay II. The operation of the remaining contact members of relay DL, and

the opening of contact members 0 and d of relay UL is without eflfect, but closure of contact members b of relay UL completes a maintaining circuit for the coil of up-direction relay 6, which is independent of car switch contact members U. This circuit extends from the coil of relay 6, through contact members c thereof, the now closed contact members 0 of down direction relay I contact members I) of leveling relay UL and through contact members a of door relay I6 to line conductor M2.

Upon being energized, intermediate-speed relay 9 is actuated to close contact members a and c, and to open contact members b. Closure of contact members a excludes resistor R2 from the circuit of field winding G thereby increasing the voltage of generator G, and causing motor M to accelerate to intermediate speed.

Closure of contact members 0 of intermediate speed relay! completes a maintaining circuit for the coils of relays 9 and II, which is independent of accelerating relay II. This circuit extends, as previously traced, through contact members 2UL of slow-down switch 2L, thence through manual-and-automatic switch SI, contact members c of intermediate-speed relay 9 and thence through the coils of relays 9 and II, as previously traced. The opening of contact members I) of intermediate-speed relay 9 interrupts the previously completed circuit for the coil of auxiliary relay I5. Upon interruption of this circuit, the energy stored in the coil of relay I discharges through a local circuit'including-resistor R'I. At the expiration of a time interval determined by the ratio of resistance to inductance in this discharge circuit, relay I5 resumes the illustrated position, thereby closing contact members a, and completing the circuit for the coil of. high-speed relay I0. The circuit'for high-speedrelay l0 extends from line conductor MI through nor mally closed contact members of relay I3, contact members :1 of reversing switch I, contact members 3UL of slowedown switch 3L, contact members b of accelerating relay II, the coil of high-speed relay I0, contact members a of relay I5 and contact members I) of door relay I6 to line conductor M2.

Upon being energized, high-speed relay I II is actuated to close contact members a and b and to open contact members 0. Opening of contact members 0 is without immediate efiect. Closure of contact members b completes a maintaining circuit for the coil 01' high speed relay III which is independent of accelerating relay II and extends, as previously traced, through contact members SUL oi slow-down switch 3L, thence through manual-and-automatic switch S2, contact members b of high-speed relay III and thence through the coil thereof to line conductor M2, as previously traced. Closure of contact members a excludes resistor R3 from the circuit of field winding Gf, thereby increasing the voltage of generator G and causing motor M to accelerate to the maximum speed. I

Referring briefly to Fig. 3, it will be observed that as car C moved upwardly from the floor landing, light sensitive device IL was first moved out of range of shield IDa and then out of range of shield IUa. As previously described, the resulting illumination of light sensitive cells DX and UK results in a further increase in the potentials of grids g of amplifiers DA and UA, thereby increasing the plate currents thereof.

I Cl

In the present description, it was assumed that the energization of sequence relay ll occurred prior to the illumination of cells UK and DX, which condition normally occurs, since, as previously described, it is usual practice for the operator to move the car switch Cs directly to the extreme position. Under these conditions, the subsequent illumination of cells UK and DX has no effect other than to further increase the excitation of the coils of leveling relays UL and DL, respectively.

If, however, it had been desired to limit the speed of the car to the high leveling speed, car switch contact members HS would not have been closed. Under these circumstances, the energization of leveling relays DL and UL would not have occurred, respectively, until light sensitive device lL was moved out of range of shields lDa and lUa to sequentially illuminate cells DX and UK. Under these conditions further, closure of contact members a of leveling relaysUL and DL would have resulted in the initial energization of the coil of high leveling speed relay 8, to accelerate the car to high-leveling-speed, since contact members 1 of relay I I would not have been closed. The eifect of the remaining contact members of leveling relays UL and DL would have been as previously described. It will be observed that during acceleration, in response to closure of car switch contact members U, the sequence of energization of leveling relays UL and DL is immaterial, and also that it is immaterial whether the energization of these relays occurs as a result of the actuation of sequence relay I! or as a result of the illumination of the light sensitive cells associated therewith.

Accordingly, it will be observed that as long as car switch contact members U and HS are maintained closed, the circuits for up-direction relay 8, main switch 5, reversing switches l and 3, brake coil Br, accelerating relay ll, sequence relay l1, high-leveling-speed relay 8, intermediatespeed relay 9, high-speed relay Ill, and leveling relays UL and DL remain complete and motor M is caused to move car C at high speed. As previously described, series field winding GSf functions in the usual manner to maintain the speed of motor M at a desired value, independent of load.

It will further be observed that, although car C may be moved past several floors, the magnetizable plates and opaque shields mounted in the hatchway are without effect on any of the slowdown switches, since the coils of slow down switches 3Land 2L are deenergized, and since sequence relay I1 maintains the grid potentials of amplifiers UA and DA at sufficiently high values that the cooperation between the cells UK and DX, and any of the shields which may be passed is not operative to affect leveling relays UL and DL.

Assuming that the elevator car is moving upwardly, at some point in the region below fioor a, and that it is desired to stop at floor b, car switch Cs may be returned to the neutral position, thereby opening contact members HS and U. The opening of contact members U is without effect, because of the previously traced holding circuit for the coil of up-direction relay 5. The opening of contact members HS interrupts the circuit for the coil of accelerating relay l I, contact members a, b, d and f of which are opened, and contact members 0 and e of which are closed. The opening of the several contact members is without effect because of the previously traced holding circuits for any relays which were initially energized by closure thereof. Closure of contact members e is without effect, since the circuit for the coil of slow-down switch 2L is now interrupted by contact members 0 of high speed relay l0. Closure of contact members c, however, completes a. circuit for the coil of slow-down switch 3L, which extends from line conductor Ml, through contact members it of main switch 5, the coil of slow-down switch 3L, contact members 0 of accelerating relay II and through manualand-automatic switch S3 to line conductor M2.

. Since the only immediate effect of centering car switch Cs is to energize the coil of slow-down switch 3L, it will be observed that the centering of the car switch, preparatory to making a. stop at floor b, may occur any time after the car C passes magnetizable plate 3Ua and before it passes magnetizable plate 3Ub. When elevator car C, moving upwardly, reaches magnetizable plate 3Ub the magnetic circuit of slow-down switch 3L is modified in the manner previously described and contact members 3UL are actuated to the open position.

The opening of contact members 3UL interrupts the circuit for high-speed relay l0, thereby causing contact members a and b thereof to open and contact members 0 thereof to close. The opening of contact members b is without efiect. The opening of contact members a reincludes resistor R3 in the circuit of field winding of Gf thereby causing the voltage of generator G to fall at a rate determined by the value of resistor R4, and causing the speed of motor M to reduce at a corresponding rate.

Closure of contact members 0 of high speed relay ID completes a circuit for the coil of slowdown switch 2L thereby preparing this switch for operation. This circuit extends from line conductor Ml through contact members I of main switch 5, the coil of slow-down switch 2L, contact members e of accelerating relay I I, contact members c of relay I0 and through manual-and-automatic switch S3 to line conductor M2.

When elevator car C brings slow-down switch '2L adjacent magnetizable plate 2Ub, contact members 2UL are actuated to the open position, in the manner described. The opening of contact members 2UL interrupts the circuit iorintermediate-speed relay 9 and sequence relay l1. Deenergization of relay 9 causes contact members a and 0 thereof to open and contact members b thereof to close. The opening of contact members c is without eiiect. Closure of contact members b recompletes the circuit for auxiliary relay I5, actuation of which is without effect, however, since the circuit for high-speed relay to has been previously interrupted. Opening of contact members a of intermediate-speed relay 9 reinserts resistor R2 in the circuit of field winding G), thereby initiating the reduction of the voltage of generator G and the speed of motor M to the high-leveling value.

Upon interruption of the circuit for the coil of sequence relay II, the energy stored therein starts to discharge through a local circuit including a resistor R8. At the expiration of an interval, determined by the ratio of resistance to inductance in this circuit, relay l1 returns to the illustrated position, opening contact members a. The opening contact members a of sequence relay H has no immediate effect, however, other than to render leveling relays UL and DL subject to shields lUb and lDb, respectively.

. Referring to Fig. 3, it will be observed that the time delay in the opening operation of sequence relay I? need only be suiiicient to maintain this relay closed from the time slow-down switch 2L is brought adjacent inagnetizable plate ZUb until light sensitive device IL is moved out of range of this magnetizable plate. It will also be observed that the tim delay is only necessary, with the illustrated arrangement, during upward travel of the car, since, during downward travel of the car, light sensitive device IL is moved out of range of inagnetizable plate 2Ub (or 2Ua, depending upon the floor selected) before slowdown switch 2L is brou ht into range thereof. In either case, however, the only requirement is that relay I? shall have resumed the illustrated positionbefore th shields are reached. In practice, to accommodate conditions which may arise during a late-stop, described hereinafter, the time delay is made sumciently long to persist during from three to four feet of car travel.

When car C brings light sensitive device IL into range or shield IDS, the light passing between source X and cell DX is interrupted, and the grid potential of amplifier DA is reduced, thereby reducing the plate current of amplifier DA. As previously described, the reduction in plate current is sufficient to cause leveling relay DL to return to the illustrated position, opening contact members a and b and closing contact members c and d.

Closure of contact members c is without effect, since contact members of up direction relay 5, connected in parallel therewith, are closed. Closure of contact members d is without effect since contact members a of door relay I6, now closed, are connected in parallel therewith. Opening of contact members I) is without effect, since down-direction relay I is not energized during upward travel. Opening of contact members a of leveling relay DL, however, interrupts the circuit for high-leveling-speed relay 8. The resultant opening of the contact members of high-leveling-speed relay 8 reincludes resistor Psi in the circuit of field winding G7, thereby initiating the reduction of voltage of the generator G and the speed of the motor M to the lowest or landing value.

When car C brings light sensitive device IL nto range of shild iUb, the light passing between roe X and cell UK is interrupted, and in re- -ponse to the resultant reduction in grid potenial of amplifier leveling relay UL is deener- :lzed and resumes the illustrated position, open- .g contact members a and b and closing contact members c and d. Openin of contact members a is without efiect since the circuit for highleveliog-speed rel y 3 has been previously interrupted. Closure of contact members 0 is wi hout effect, since these contact members are connected in parallel with the now closed contact members d and a of relays DL and H3 respectively. Cl0 sure of contact members (1 is without effect, since the circuit for down-direction relay 7 is interrupted elsewhere. Opening of contact members I) of leveling relay UL, however. interrupts the previously traced holding cir uit for up-direction reiay 6. Upon interruption of this chcuit, contact member a, b and 0 thereof are opened and contact members 6. thereof are closed. The operation of contact members a, c and d is without efiect, but the opening of contact members I) interrupts the circuit for main switch '5 and reversing switches i and 3, all of which return to the illustrated position.

The opening of contact members a of reversing switches I and 3 interrupts the circuit for field winding Gf thereby initiating the reduction of the voltage of generator G to a value determined by the residual magnetism thereof. The opening of contact members (1 and e of reversing switch I is without effect since the circuits controlled thereby have been previously interrupted. The opening of contact members I; of reversing switch I and line switch 5 interrupts the circuit for release coil Br, thereby causing the application of brake B. Closure of contact members a of main switch 5 completes the circuit for the demagnetizing field winding GAF which, as previously described, is wound to produce a magnetomotive force in opposition to the residual magnetism of generator G, and to thereby reduce he voltage of that machine quickly to substantially zero. The opening of contact members cl, f and e deenergizes the coils of slow- down switches 3L and 2L, and of relay l5, respectively. The opening of contact members 0 is without effect.

As previously described, due to the action of series field winding GS), the speed of the motor M is maintained substantially constant independent of load. Accordingly in the majority of cases, deenergization of relay UL to interrupt the reversing circuit, apply the brake, and apply the demagnetizing field, results in the stoppage of the elevator car at a position accurately level with the floor landing.

Assuming, however, that for some reason, elevator car C failed to stop accurately level with floor landing b, or that, after having stopped level therewith drifted to a point sufiiciently above the fioor to move light sensitive device IL out of range of plate IDb, light sensitive cell DX is again illuminated to effect the following leveling operations.

As previously described, illumination of light sensitive cell DX results in a suiiicient incr ase in the plate current of amplifier DA to cause actuation of leveling relay DL. Upon actuation of relay DL, contact members a and 1) thereof are closed and contact members 0 and cl thereof are open. Closure of contact members a prepares a circuit for high-leveling-speed relay 3. Opening of contact members c of relay DL prevents energization of up-direction relay 6. Opening of contact members (1 of relay DL is without effect, since the now closed contact members 0 of relay UL are connected in parallel therewith.

Assuming the doors are closed, relay I6 is still energized and the contact members a. thereof complete a second circuit in parallel to contact members 0 of relay UL. Closure of contact memhers I) of relay DL completes a circuit for the coil of down-direction relay I, which extends from line conductor MI through the coil of down-direction relay I, the now closed contact members d of up-leveling relay UL, contact members I; of down-leveling relay DL, the now closed contact members (1 of up-direction relay G, and thence to line conductor M2 through either the normally closed contact members 0 of relay UL or contact members a of relay I6.

Upon completion of this circuit, down-direction relay I is actuated to open contact members 0 and to close contact members a, b and d. Closure of contact members (i of relay I completes a selfholding circuit therefor, which is independent of contact members (1 of up-leveling relay UL. Opening of contact members 0 of relay 1 is without effect since the circuit for up-direction relay 6 is interrupted elsewhere. Closure of contact members a of relay 1 is without effect since the circuit for accelerating relay II is interrupted at car switch contact members HS. Closure of contact members b of relay I completes a circuit for the coil of main switch and down reversing switches 2 and 4, which extends from theline conductor Mi through thecoil of main switch 5, contact members a of voltage-relay l4, the coils of switches 2 and 4, and contact members b of relay 1 to line conductor M2. Upon completion of this circuit, main switch 5 functions as in the previously described accelerating operation, and reversing switches! and 4 close to perform the functions attributed to switches i and 3 in the previous operation, with the exception that field winding Gf is connected between line conductor MI and M2 in the reverse direction. Accordingly, upon closure of down-leveling relay DL, the. voltage of generator G rises to the minimum value, the brake is released and elevator car C is returned slowly to the fioor landing.

It will be obvious from the above description that had the elevator car drifted below the fioor landing, in response, for example, to the placing of a sumcient load thereon to stretch the hoisting cables, leveling relay UL would have been energized to initiate a leveling movement in the upward direction.

In the above paragraphs, it is assumed that the upward drift of the elevator car is arrested, and the downward leveling movement initiated, while light sensitive device IL is darkened by shield lUb. Under these circumstances, up-leveling relay UL is not energized and contact members 0 thereof remain closed. Similarly, in the event of up ward leveling movement initiated from a point at which shield IDb prevents illumination of light sensitive cell DX, down leveling relay DL remains deenergized throughout the leveling movement. Noting that contact members c of relay UL, contact members d of relay DL and contactmembers a of door relay it are all connected in parallel,

it becomes obvious that leveling movement of car C between the upper limits of shield iUb or the lower limit of shield lDb (or shields lUa and lDa, depending upon the floor at which the car is located) can be effected while a door, or the eleva-' tor car gate is open.

In the above paragraphs, the decelerating op eration was described as being entirely automatic in operation. As further described, in a system of this character, the stoppage of the car level with the floor usually occurs in the first instance, and the need of a leveling movement occurs as the result of the car drifting away from the floor in response, for example, to the stretching or contracting of the hoisting cables when heavy loads are placed on, or removed from, the car. Since the drift normally occurs at a relatively low rate, the return movement is almost always initiated before light sensitive device IL is moved out of range of shield lUb,in the case of an upward drift, or out of range of shield mo in the case of a downward drift.

, In systems, however, in which the intermediate and high-speed, steps are controlled entirely by the car switch, a more extensive leveling movement is frequently required, and a higher leveling speed desirable during the initial portion thereof.

The system illustrated in Fig. 1 may be transformed from one in which the entire decelerating ing manualand-automatic switch Si prevents completion of a maintaining circuit for relays 9 and I1 and places these relays exclusively under the control of accelerating relay ll. Similarly, opening manual-and-automatic switch S2 prevents completion of a self-holding circuit for high-speed relay l0, thereby placing this relay under the exclusive control of accelerating relay ll. Opening manual-and-automatic switch S3 prevents completion of the circuits for the coils of slow- down switches 3L and 2L, thereby rendering these devices inefiective. I

With the exception, however, that the above maintaining circuits are not completed, if switches SI, S2 and S3 are opened, the accelerating operation is as previously described. Assuming, accordingly, that the elevator car is traveling at high speed, and, as before, that it is desired'to stop at floor landing 1), car switch Cs is maintained in the extreme position until the elevator car reaches a point approximately the normal slow-down distance in advance of floor b. As previously described, the opening of car switch contact members U is without effeet, and the opening of car switch contact members HS results in the deenergization of accelerating relay II. In this case, however, the deenergization of accelerating relay ll results in the immediate interruption of the circuit for the coil of relay l0 (contact members 11 of relay H) and the immediate interruption of the circuit for the coils of intermediate speed relay 9 and sequence relay I! (contact members d of relay ll). As previously described, high-levelingspeed relay 8 is maintained energized through the now closed contact members a of relays DL and UL.

As previously described, the opening of contact members a of relays l0 and 9 reduces the excitation of winding G1, andinitiates a reduction of the voltage of generator G and the speed of motor M to the high-leveling value.

In practice, elevator operators are able to identify approximately the point in advance of the floor at which the car switch should be centered. It will be observed, however, that in systems operating at, for example, 600 feet per minute, a delay in the centering of the car switch for even a fraction of a second results in a variation of a foot or more, in either direction, of the point at which deceleration is initiated.

If deceleration is prematurely initiated, the elevator car normally attains the high-levelingspeed at some distance in advance of the floor and is then stopped therewith accurately inthe first instance, as in the case of an entirely automatic deceleration. In case the deceleration is initiated too late, the car may be expected to approach the floor at too great a rate to be stopped accurately level therewith in the first instance and either a low speed, or perhaps a high speed, leveling movement becomes necessary.

In either case, it is necessary that the car travel a greater distance between the time the circuit for the coil of sequence relay I1 is interrupted and the time contact members a thereof are open, than is necessary when the car is being operated with fully automatic deceleration. The additional distance of car travel is required, since, while in an automatic deceleration, the circuit for the coil of sequence relay I1 is interrupted when the car reaches the intermediate speed magnetizable plates, in a manual deceleration the corresponding circuit is interrupted at the time deceleration is initiated.

In the usual case, assuming an automatic deceleration requires from 10 to 11 feet of car travel, it may be expected that a manually initiated deceleration will require from 8 to 9 feet of car travel. It is desirable therefore to provide that contact members of relay II will remain closed while the car is traveling a distance of from 5 to 6 feet, in order to insure that light sensitive device IL will have passed the intermediate speed magnetizable plates before relays UL and DL are rendered subject to the cells UK and DX.

In practice, it is usually found that an adjustment of the discharge circuit of relay II which is appropriate during fully automatic operation is also appropriate during manual operation, since, although the latter case requires a greater distance of car travel, it will be observed that the elevator car operates at a higher average speed throughout the time interval, As will be obvious, the timing of relay I1 may be adjusted, if necessary, by varying the value of resistor R8 or in any other suitable manner as by the use of dash pots or the like.

Assuming that the deceleration was initiated sufficiently late to require a high speed leveling movement and that the car has been decelerated to the high leveling speed by the opening of relays 9 and ID, as described, the following operations occur.

When car C brings light sensitive device IL into the range of shield IDb, leveling relay DL is deenergized in the manner previously described, thereby deenergizing high-leveling-speed relay 8, the opening of which tends to reduce the speed of motor M to the lowest or landing value. As also previously described, when car C brings light sensitive device into range of shield IUb, leveling relay UL is deenergized, thereby deenergizing updirection relay 6, main switch 5 and reversing switches I and 3, the opening of which tends to bring the car to rest. As the car continues past the floor, and light sensitive device IL passes out of range of shield IDb, down-leveling relay BL is energized in the manner previously described, to complete a circuit for the coil of down-direction relay I. Energization of relay I, in turn, causes actuation of main switch 5 and down- 1eversing switches 2 and 4, operations of which condition the system for downward movement at the lowest or landing speed.

As the elevator car continues past the floor and light sensitive device IL is moved out of range of shield IUb, up-leveling relay UL is energized to close contact members a and b and to open contact members 0 and d. Closure of contact members a of up-leveling relay UL completes a circuit for high-levelling-speed relay 8, closure of which increases the excitation of field Winding Gf to a value corresponding to the highleveling-speed of motor M. Closure of contact members I) of relay UL is without effect since the circuit for up-direction relay 6 is interrupted elsewhere. Provided door relay I6 is still closed, the opening of contact members 0 of relay UL is without effect.

In the previously described low speed leveling operation, it was noted that the opening of the doors was without effect. While car C is in the high-leveling-speed Zone, however, it will be observed that the doors must be maintained in the closed position, it being undesirable to permit more than a very limited amount of movement on either side of the floor with the doors open. The opening of contact members d of relay UL is without effect, since contact members a of down direction relay I, connected in parallel therewith, are now closed.

As a result of the completion of the above described circuits, generator G generates voltage of proper polarity and of sufficient value to cause motor M to move car C downwardly at high-leveling-speed. As shown, accordingly, as soon as the upward movement is arrested, the downward movement is initiated. As car C approaches the floor landing, light sensitive cells UX and DX are sequentially darkened to first reduce the speed of the car to the lowest or landing value, and to then bring the car to rest in the manner previously described.

It is believed to be obvious from the above example that it is immaterial how far the car drifts past the floor landing before the return movement is initiated, and that the only manner in which the length of the shield IUb effects the leveling movement is to determine the point at which the elevator speed changes from high-levcling-speed to the lowest or landing-speed, and to limit the region above the floor throughout which the car may be moved with the doors open.

It is also believed to be obvious that, had the car been moving downwardly, and an upward leveling movement become necessary, during such return movement the deenergization of relay DL would have caused the reduction from high-leveling-speed to low-leveling speed and up-leveling relay UL would have caused the stopping of the car. It will be observed, accordingly, that relays UL and DL may perform either a decelerating function or a stopping function. In the case of downward leveling movement, relay UL controls the deceleration from high-leveling-speed to lowleveling speed, while in the case of an upward leveling movement, this relay controls the stopping; in the case of an upward leveling movement, relay DL controls the deceleration from high-leveling-speed to low-leveling speed while in the case of a downward leveling movement, this relay controls the stopping of the car.

In the above-described examples of manually initiated decelerating operations, it was assumed that the time interval of sequence relay H expired before either of the shields associated with the selected floor landing were reached. It is believed to be obvious, however, that if deceleration is initiated at a point such that relay II times out before shield lUb is reached but after shield IDb is reached, the deceleration from highleveling-speed to low-leveling-speed will be delayed until the opening of contact members a of sequence relay II. Similarly, if deceleration is initiated at such a point that sequence relay I1 times out before shield IDb is passed but after shield IUb is reached, the interruption of both the high-leveling-speed circuit and the reversing circuits will occur at the time contact members a of relay II open.

In the relatively unusual case in which deceleration is initiated so late that sequence relay I'I does not time out until after shield IDb is passed, during upward travel, or until after shield IUb is passed during downward travel, the late-stop feature of the present invention, next to be described, may be relied upon.

In the stopping operations thus far described, it has been assumed, in the case of the automatic slow-down, that the car switch was centered sufficiently early to permit proper operation of slowdown switch 3L, in the case of manual slow-down, that the car switch was centered at a point near the normal point of slow down. It sometimes happens, however, that the operator does not become aware that a stop should be made until the car has approached the selected floor too closely for the slow-down mechanism to function in the normal and above described manner.

The present invention further comprises an arrangement of apparatus whereby, under the latter conditions, the elevator car may be brought to rest more promptly than in the usual cases of either manual or automatic deceleration.

As previously described, in a representative system of the illustrated typ arranged for operation at 600 feet per minute, the slow-down distance, during automatic operation is of the order of from ten to eleven feet; the slow-down distance, during manual operation, is of the order of from eight to nine feet. In a representative system embodying what may be termed the "late-stop feature of the present invention, however, the car may be expected to travel only a distance of from six to seven feet in the course of the stopping operation. For descriptive purposes, late-stop operations may be classified into those in which first, the stopping operation is initiated sufficiently early to permit the car to come to rest before either of the shields associated with the selected floor are reached; and second, those in which the stopping operation is initiated so late that the car continues in motion after the shields are reached.

As previously described, assuming the associated circuit for relay I1 is interrupted when the car is traveling at high speed, an adjustment of the timing of contact members thereof whereby these contact members are maintained closed while the car is traveling a distance of from five to six feet is appropriate. with such an adjustment, it will be observed that the time interval of relay I! will have expired before the car comes to rest in a late-stop operation of the first of the above two classes.

In the case of a late stop operation of the second of the above two classes, the switching sequence depends upon the position of the car with respect to the shields at the time the contact members a of relay I! open. Accordingly, for purposes of description, late-stops of the second class may be reclassified into those in which relay Il times out while light sensitive device is opposite shield ID!) (or IDa) during upward travel, or shield IUb (or IUa) during downward travel; and those in which during upward travel, shield IDb (or IDa), during downward travel, shield IUb (or IUa) is passed before relay I1 times out. I

Accordingly, assuming that car .0 is moving upwardly at full speed and that, while the car is more than six or seven feet in advance of floor b, the operator becomes aware that a stop should be made at floor b, a late stop of the first class is in order, and involves the following sequence.

In accordance with the present system, the late-stops are initiated by centering the car switch and momentarily closing the opposite direction contact members. As previously described, the opening of car switch contact members U is without eflect, and, assuming switches SI, S2 and S3 are again closed, the opening of car switch contact members HS has no effect other than to deenergize accelerating relay II, which in turn, energizes the coil of slow-down switch 3L.

Closure of car switch contact members D completes a circuit for the coil of down-direction relay I. Upon completion of this circuit, relay I is actuated to close contact members a, b and d and to open contact members 0. Closure of contact members a and d is without immediate effeet. The opening of contact members 0, however, interrupts the circuit for the coil of updirection relay 6, contact members a, b and c of which open and contact members d of which close.

Closure of contact members b 'of down-direction relay 1 completes a circuit for the coils of main switch and down reversing switches 2 and 4. Main switch 5, which has been previously energized is maintained in the energized position through this circuit, but reversing switches 2 and 4 are not energized, since contact members a of anti-plugging relay I4 are now open, and the drop across resistor R9, while permitting passage of sufiicient current to maintainany of the switches in circuit therewith in the closed position, permits the passage of insufficient current to initially actuate any of such switches.

The coil of anti-plugging relay I4 is connected directly across the terminals of generator G, and is designed to be maintained in the circuit opening position until the voltage of generator G has fallen to a value sufficiently low to permit reversal of the voltage of generator G without unclue disturbance to the system. Preferably, although not necessarily, relay I4 is so'designed that the contact members thereof are maintained open until the car comes to rest. The point, during acceleration, at which anti-plugging relay I4 is actuated is immaterial, in the present system.

The opening of contact members a and c, and closure of contact members d of up direction relay 6, is without effect. The opening of contact members b, however, interrupts the circuit for the coils of reversing switches I and 3, the on cuit for the coil of main switch 5 being maintained in the manner described above. The opening of contact members b, d, e and f of reversing switch I interrupts the circuits for the coils of the electromagnetic brake, of high-speed relay III, of intermediate-speed relay 9 and sequence relay I1, and of high-leveling-speed relay 8, respectively. The opening of contact members a of switches I and 3 interrupts the circuit for field winding GI and for the coil of auxiliary relay I2.

Upon interruption of the above circuits, the current in winding G) and through the coil of relay I2 decays at a rate determined by the ratio of the inductance of these windings to the resistance of resistor R4, and the voltage of generator G and speed of motor M are reduced at a corresponding rate, the deceleration of motor M being further assisted by the action of brake B.

Since the contact members of relay I2 do not open immediately upon interruption of the reversing circuit, closure of contact members 0 of reversing switch I completes a circuit for the coil of speed-limiting relay I3, which extends from line conductor MI through the coil thereof, through contact members of current relay I2, in series through normally closed contact members c of reversing switches 2 and I, and through contact members 0 of main switch 5, to line conductors M2. Upon completion of this circuit, speed-limiting relay I3 is actuated to close contact members a and to open contact members b. Closure of contact members a completes a selfholding circuit for relay I3, which remains complete until main switch 5 is deenergized, at the expiration of the stopping operation. The opening of contact members I) prevents completion of the circuits for relays l0, 9 and H. In view of the interlock provided by contact members I) of relay 3, it will be observed that, even though the late-stop is initiated by moving car switch C8 to the extreme position in the opposite direction, thereby reclosing contact members HS, the only effect of such reclosure is to energize accelerating relay Ii, closure of which is without efiect.

Upon being energized, down-direction relay '1 completes a self-holding circuit, which extends from the coil thereof, through contact members d thereof, contact members 2) of leveling relay DL, the now closed contact members d of updirection relay 5 and through contact members a of door relay #8 to line conductors M2. It is seen, therefore, that the reverse direction contact members need be closed only momentarily to initiate the late-stop.

It will be observed that the late-stop is effected by removing the external source of excitation for field winding G) and by causing the application of brake B, thereby initiating a relatively high rate of deceleration of the elevator car, but that, although this operation is initiated by closing the opposite direction relay (down-direction relay l), anti-plugging relay It prevents completion of the down-direction generator field circuit, and speed-limiting relay l3 prevents recomple tion of the several accelerating circuits.

In the present example, it was assumed that the late-stop was initiated sufficiently early to permit the elevator car to come to rest at a point in advance of the shields associated with floor landing 17. Accordingly, in order to cause the car to continue to a position level with floor landing b, car switch Cs may again be actuated either to momentarily close only contact members U or to also momentarily close contact members HS.

Closure of contact members HS is eifective only to energize accelerating relay ll, closure of which is without effect, since contact members a of speed limiting relay l3 are now open. Closure of contact members U completes a circuit for the coil of Lip-direction relay 6.

Upon com letion of this circuit, up-direction relay 5 is again actuated to close contact members a, b and c and to open contact members (Z. Closure of contact members a of relay 6 is without effect. The opening of contact members (1 of relay 6 interrupts the previously traced selfholding circuit for the coil of down-direction relay 1, thereby causing contact members a, b and d thereof to reopen and contact members thereof to reclose. Closure of contact members 0 of relay 6 completes a self-holding circuit there for, in the manner previously described. Closure of contact members b of relay 5, which precedes the opening of contact members b of relay 1, maintains main switch in the actuated position, and prepares a circuit for the coils of reversing switches and 3 which is, however, subject to anti-plugging relay l4.

Since the only efiect of the momentary reclosure of contact members U is to destroy the previously prepared circuit for down- direction reversing switches 2 and 4, and to prepare a circuit for up-reversing switches l and 3, it will be observed that this operation may occur at any time after the late-stop is initiated, and before elevator car C comes to rest.

At substantially the same time that elevator car C comes to rest, contact members a of antiplugging relay I4 are released to the illustrated position, thereby causing reversing switches I and 3 to close. switches I and 3 now being closed, elevator car C accelerates to the high-leveling-speed in the manner described in the first accelerating operation. When light sensitive cell DX is darkened by shield lDb, leveling relay DL is deenergized to interrupt the circuit for high-levelingspeed relay 8, and when light sensitive cell UK is darkened by shield lUb, leveling relay UL is deenergized to cause interruption of the circuit for field winding G), apply brake B and apply the demagnetizing field winding GM and thereby bring the car to rest.

In a case in which the late-stop is initiated so late that elevator car C cannot be brought to rest until after the shields associated with the selected floor landing are reached, the late-stop is initiated in the manner described above, with the exception that the momentary reclosure of the up direction car switch contact members U is unnecessary. Assuming, accordingly, that the down direction contact members D of car switch Cs have been momentarily closed to deenergize up-direction relay 6 reversing switches I and 3, speed relays l0, 9 and 8 and sequence relay l1, and to prepare circuits for down- direction reversing switches 2 and 4, the late-stop may be completed in any one of the following manners.

If sequence relay ll times out, at any time before light sensitive device IL is brought adjacent shield lDb, the opening of contact members a of relay I! will have no effect other than to render leveling relay DL subject to the shield. In this case, when shield lDb darkens cell DX, leveling relay DL is deenergized, thereby deenergizing down-direction relay 1, the opening of which deencrgizes main switch 5 and destroys the previously prepared circuit for down reversing switches 2 and 4, thereby tending to bring the car immediately to rest.

If the opening of contact members a of sequence relay ll occurs after light sensitive cell DX has been darkened, the opening of these contact members results in the immediate deenergization of leveling relay DL, to thereby deenergize down direction relay 1.

If the deenergization of relay 1 occurs at any time before light sensitive cell UK is darkened by shield IUb, leveling relay UL will be in the actuated position. Accordingly, upon deenergization of down-direction relay 1, up-direction relay 6 will again be actuated to recomplete the circuits for main switch 5 and reversing switches I and 3 to thereby cause the elevator car to continue to the floor landing at low-leveling-speed. As previously described, when cell UK is darkened by shield IUb, leveling relay UL is deenergized and the elevator car brought to rest level with the floor.

If contact members a of sequence relay I! remain closed until after light sensitive device IL is moved completely past shield iDb, down direc tion relay 1 will remain energized, and as soon as the car is brought to rest and anti-plugging relay M resumes the illustrated position, down reversing switches 2 and 4 will be actuated to cause the elevator car to start downwardly. If the return movement is initiated while light sensitive device IL is within range of shield lUb, such return movement will be effected at low speed, since the Main switch 5 and reversing circuit for high-leveling-speed relay 8 will be open at contact members a of leveling relay UL. If, however, the return movement is not initiated untfl after light sensitive cell UXhas again become illuminated, leveling relay UL will also be energized, thereby energizing high-leveling-speed relay 8, and the car will travel at high-levelingspced until light sensitive cell UK is again darkened. In either case, the return movement will be interrupted and the carbrought to rest level with floor landing b when light sensitive cell DX is again darkened by shield lDb.

In the extreme case, in which the late-stop is initiated so late that the car not only continues past the selected floor landing, but also past the magnetizabie plates associated with slow down switch 2L, it is only necessary that the down-direction car switch contact members be maintained in the closed position until the car has restarted, and has repassed these magnetizable plates. At any time after the magnetizable plates are passed, car switch Cs may be returned to the neutral position and the car will continue toward the floor at high-leveling-speed, the deceleration to low landing speed and the stopping operation taking place as previously described.

1 In the previously described examples of latestops, it is assumed that manual-and-automatic switches SI, S2 and S3 occupy the closed positions. It will be observed however, that if these switches are opened and the car operated with manual control of the higher speed steps, latestops are effected in exactly the same manner, and involve essentially the same switching operations,

' the only difierence being that the deenergization of high-speed relay ID, of intermediate-speed relay 9 and sequence relay 1, and of high-levelingspeed relay 8 occurs as the result of the opening or accelerating relay ll rather than the opening of reversing switch I, or reversing switch 2, depending upon the direction of travel.

In the above described examples, it is assumed that deceleration is initiated from high speed. In a system operating at 600 feet per minute, an elevator car cannot be accelerated and decelerated, to and from, full speed in the distance between two adjacent floors of the usual building structure. In the present system, however, it will be observed that the closure, during acceleration, oi high-speed relay I is delayed by auxiliary accelerating relay [5. Accordingly, if it is desired to cause the car to travel only the distance between two adjacent floors, the speed of the elevator car may be limited to the intermediate value by reopening car switch contact members HS before auxiliary relay l has timed out to permit closure of high-speed relay l0.

With the exception of the detailed description of both high and low-speed leveling movements in both directions, the present description has been limited to switching operations involved in upward travel of the car. It is believed obvious, however, that the acceleration of the elevator car to high speed in the downward direction, and the deceleration of the car from high speed, when moving downwardly, are identical with the corresponding up-direction operations with the exception that car switch contact members U, updirection relay 6, reversing switches l and 3, and contact members 2UL and 3UL of slow- down switches 2L and 3L are replaced, respectively, by car switch contact members D, down-direction relay 1, reversing switches 2 and 4, and contact members 2DL and SDL of slow- down switches 2L and 3L.

While I have described and illustrated a preferred embodiment of the present invention, it is to be understood that various modifications and changes may be made without departing from the scope thereof. Accordingly, I desire that only such limitations shall be placed thereon as are imposed by the prior art and defined in the appended claims.

I claim as my invention:

I. In an elevator system, an elevator car 0perable in a hatchway, a plurality of sets of contact members associated with said system, an operator for each of said sets of contact members, each of said operators comprising a first element and a second element, certain of said first elements having characteristics such that they cooperate only with corresponding second elements, means for mounting said first elements on said car in substantially the same vertical line and means for mounting said second elements at predetermined points in said hatchway in substantiallya vertical line for cooperation with said first elements, whereby said contact members may be selectively controlled in accordance with the position of said car by operators occupying a small cross-sectional area of said hatchway.

2. In an elevator system, an elevator car operable in a hatchway, two members relatively movable in accordance with the position of said car in said hatchway, a plurality of circuit controlling devices associated with said system, means for mounting said devices on one of said members at predetermined points in substantially the same vertical line, a plurality of elements for operating said devices when said devices are in predetermined condition of energization, certain of said elements having characteristics such that they are operably cooperative with only certain of said devices, means for establishing said predetermined conditions of energization of said devices and means for mounting said elements on the other of said members at predetermined points in substantially said same vertical line for cooperation with said devices, whereby said devices may be selectively operated in accordance with the position of said car with small lateral space requirements.

3. In an elevator system, an elevator car operable in a hatchway, a plurality of circuit controlling devices associated with said system, means for mounting said devices on said car in substantially the same vertical line, a plurality of elements for operating said devices where said devices are in predetermined conditions of energization, certain of said elements having characteristics such that they are operably cooperative with only certain of said devices, means for establishing said predetermined conditions of energization of said devices, and means for mounting said elements in said hatchway at predetermined points in substantially said same vertical line for cooperation with said devices, whereby said devices may be selectively operated in accordance with the position of said car with small lateral space requirements.

4. In an elevator system, an elevator car operable in a hatchway, a'plurality of circuits associated with said system, and means to commutate said circuits comprising a circuit controlling device indlvidual to each of said circuits, means for mounting said devices on said car in substantially the same vertical line, a plurality of elements effective to operate said devices when said devices are in predetermined conditions of energization, certain of said elements having characteristics all) such that they are operably cooperative with only certain of said devices, means for establishing said predetermined conditions of energization of said devices, and means for mounting said elements in said hatchway at predetermined points in substantially said same vertical line for cooperation with said devices, whereby said circuits may be selectively commutated in accordance with the position or" said car with small lateral space requirements of said devices, and said operating elements.

5. In an elevator system, an elevator car operable in a hatchway, driving means for said car, means to decelerate said car including a plurality of circuits, and means to commutate said circuits including a circuit controlling device individual to each of said circuits, means for mounting said devices on said car in substantially the same vertical line, a plurality of elemerits eiiective to operate said devices when said devices are in predetermined conditions of energization, certain of said elements having characteristics such that they are operably cooperative with only certain of said devices, means for establishing said predetermined conditions of energization of aid devices, and means for mounting said elements in said hatchway at predetermined points in substantially said same vertical line for cooperation with said devices, whereby said decelerating means may be selectively controlled in accordance with the position of said car with small lateral space requirements of said devices and said operating elements.

6. In an elevator system, an elevator car operable in a hatchway, a plurality of sets of contact members associated with said system, an operator for one of said sets of contact members comprising apparatus having two cooperating magnetic elements, an operator for another of said sets of contact members comprising apparatus having two elements, one of said elements comprising a light sensitive cell, the other of said elements comprising means to effect a predetermined condition of illumination of said cell when in a predetermined position with respect thereto, said last named means having characte stics such that it is not operably cooperative with elements of said first named operator, means for mounting one element of each of said operators on said car in substantially the same vertical line, means for mounting the remaining element of each of said operators in said hatchway at predetermined points in substantially said same vertical line for cooperation with said carcarried elements, whereby said contact members may be controlled in accordance with the position of said car with small lateral space requirements of said operators.

7. In an elevator system, an elevator car operable in a hatchway, a plurality of sets of contact members associated with said system, an operator for a set of said contact members comprising apparatus having magnetizing and magnetizable elements, an operator for another set of said contact members comprising apparatus having a light sensitive cell element and a cooperating element adapted to eiiect a predetermined condition of illumination of said cell when in a predetermined position with respect thereto, said cooperating element having characteristics such that it is not operably cooperative with the elements or" said first named operator, means for mounting said light sensitive and magnetizing elements on said car in substantially the same vertical line, means for mounting said magnetizable and cooperating elements in said hatchway at predetermined points in substantially said same vertical line for cooperation with said car carried elements, whereby said contact members may be controlled in accordance with car position with small lateral space requirements of said operators.

8. In an elevator system, an elevator car operable in a hatchway, a plurality of sets of contact members associated with said system, an operator for a set of said contact members comprising apparatus having two cooperating magnetic elements, an operator for another set of said contact members comprising apparatus having two elements, one of said elements including a light-sensitive cell and a source of light disposed to illuminate said cell, the other of said elements including means to control the passage of light between said source and said cell in accordance with the relative positions of said two elements, said last named element having characteristics such that it is not operably cooperative with the elements of said first named operator, means for mounting one element of each of said operators on said car in substantially the same vertical line, means for mounting the second element of each of said operators in said hatchway at predetermined points in substantially said same vertical line for cooperation with,

said car-carried elements, whereby said contact members may be controlled in accordance with car position with small lateral space requirements of said operators,

9. In an elevator system, an elevator car operable in a hatchway, a plurality of sets of contact members associated with said system, an operator for one of said sets of contact members comprising apparatus having magnetizing and magnetizable elements, an operator for another of said sets of contact members comprising apparatus having two elements, one of said elements including a light sensitive cell and a source of light disposed to illuminate said cell, the other of said elements including means to control the passage of light between said source and said cell in accordance with the relative positions of said two elements, said last named element having characteristics such that it is not operably cooperative with the elements of said first named operator, means for mounting said magnetizing and light sensitive elements on said car in substantially the same vertical line, means for mounting said magnetizable and light-controlling elements in said hatchway at predetermined points in substantially said same vertical line for cooperation with said car carried elements, whereby said contact members may be controlled in accordance with car position with small lateral space requirements of said operators.

10. In an elevator system, an elevator car operable in a hatchway, a plurality of sets of contact members associated with said system, and means for sequentially operating said sets of contact members in accordance with the position of said car in said hatchway, said operating means comprising an operator for each of said sets of contact members, each of said operators comprising a first element, a second element and means to condition said operator for operation through cooperation between said first and second elements, certain of said first elements having characteristics such that they are operably cooperative only with certain of said second elements, means for mounting said first elements on said car in substantially the same vertical line, means for mounting said second elements in said hatchway in accordance with said sequence at predetermined points in substantially said same vertical line, whereby said sets of contact members may be sequentially controlled with small lateral space requirements of said operators.

11. In an elevator system, an elevator car operable in a hatchway, two sets of contact members associated with said system, and means for sequentially operating said sets at predetermined,

points comprising an operator for each of said sets, each operator comprising a first element, a secondelement and means to condition said operator for operation through cooperation between said first and second elements, the second element of one of said operators having characteristics such that it is not operably cooperative with the elements of said other operator, means for mounting the first elements of said operators on said car in substantially the same vertical line and means for mounting the second elements of said operators in said hatchway at predetermined points in substantially said same vertical line for cooperation with said car carried elements, whereby said sets of contact members may be alternately controlled with small lateral space requirements of said operators.

12. In an elevator system, an elevator car operable in a hatchway, two sets of contact members associated with said system, means for operating one of said sets of contact members when said car reaches certain positions in said hatchway, and for operating the other of said sets of contact members when said car reaches certain other positions in said hatchway, said operating means comprising an operator for each of said sets, each of said operators having a first element, a plurality of second elements, and means to condition each operator for operation through cooperation between the associated first and second elements, the second elements associated with one of said operators having characteristics such that they are operably cooperative with onlythe first element of that operator, means for mounting said first elements on said car in substantially the same vertical line, means for mounting the second elements associated with the operator for said one or said sets of contact members in said hatchway at said certain positions in substantially said same vertical line, and means for mounting the second elements associated with the operator for said other set of contact members in said hatchway at said certain other positions in substantially said same vertical line, whereby said contact members may be controlled with small lateral space requirements of said operators.

13. 'In an elevator system, an elevator car operable in a hatchway, a plurality of sets of contact members associated with said system, means for sequentially operating said sets of contact members in accordance with car position comprising an operator for each of said sets of contact members, each of said operators having two elements, the elements of one of said operators being arranged to cooperate magnetically, one element of a second of said operators comprising a light sensitive cell, the other element of said second operator comprising means to eiTect a predetermined condition of illumination of said cell when in a predetermined position with respect thereto, said last named element having characteristics such that it is not operably cooperative with elements of said one of said operators, means for mounting one element of each of said operators on said car in substantially the same vertical line and means for mounting the other elements of each ocf said operators in said hatchway in accordance with said sequence at predetermined points in substantially said same vertical line, whereby said sets of contact members may be sequentially controlled with small lateral space requirements of said operators. 14. Inan elevator system, an elevator car operable in a hatchway, two sets of contact members associated with said system, an operator for each of said sets of contact members, each of said operators having first and second elements, the second element associated with one of said operators having characteristics such that it is operable cooperative with only the first element associated with that operator, means for mounting said first elements on said car in substantially the same vertical line, means for mounting said second element in said hatchway at predetermined points in substantially said same vertical line for co-,

operation with said car carried elements, and means to prevent operative cooperation between the first element of said one of said operators and the second element, associated with the other of, said operators, whereby each of said sets of contact members may be operated at difierent predetermined points with small lateral space requirements of said operators.

15. In an elevator system, an elevator car up,- erable in a hatchway, two circuit controlling devices associated with said system, means for mounting said devices on said car in substantially the same vertical line, an operating element associated with each of said devices, the operating element associated with one of said devices having characteristics such that it is operably cooperative with only that device, means for mounting said elements in said hatchway at predetermined points in substantially said same vertical line for cooperation with said devices, and means for preventing operative cooperation between said other device'and the element associated with said one of said devices, whereby said devices may be operated at difierent points with small lateral space requirements of said devices.

16; In an elevator system, an elevator car operable in ahatchway, two circuits associated with said system, means for commutating said circuits comprising an operator individual to each circuit,

each operator having first and second elements,

the second elements associated with one of said operators having characteristics such that it is operably cooperative with only the first element of that operator, means for mounting said first tate the associated circuit when the first elementassociated therewith is in cooperative relation with the second element associated with said other operator, whereby said circuits may be commutated at different points with small lateral space requirements of said operators.

17. In an elevator system, an elevator car operable in a hatchway, two sets of contact members associated with said system, an operator for one of said sets comprising two magnetic ele-1 ments, an operator for the other set comprising a light sensitive, cell element and an element adapted to efiect a predetermined condition of illumination of said cell when in apredetermined position with respect, thereto, said last named element having characteristics such that it is not operably cooperative with the elements of said first named operator, means for mounting one element of each of said operators on said car in substantially the same vertical line, means for mounting the other element of each of said operators in said hatchway at predetermined points in substantially said same vertical line, and means for preventing operative cooperation between said light sensitive cell element and a magnetic element, whereby said sets of contact members may be selectively operated at different points with small lateral space requirements of said operators.

18. In an elevator system, an elevator car operable in a hatchway, two sets of contact members associated with said system, an operator for one of said sets comprising magnetizing and magnetizable members, an operator for the other of said sets comprising a light sensitive cell element and an element adapted to effect a predetermined condition of illumination of said cell when in a predetermined position with respect thereto, said last named elements having characteristics such that it is not operably cooperative with the elements of said first named operator, means for mounting said magnetizing and cell elements on said car in substantially the same vertical line, means for mounting said magnetizable and conditioning elements in said hatchway at predetermined points in substantially said same vertical line, and means to prevent operative cooperation between said cell element and said magnetizable element, whereby said sets of contact members may be selectively operated at different points with small lateral space requirements of said operators.

19. In an elevator system, an elevator car operable in a hatchway, two sets of contact members associated with said system for controlling circuits of the system, an operator for controlling one of said sets having magnetizing and magnetizable elements, an operator for controlling the other of said sets having two elements, one of said elements comprising a light sensitive cell and a source of light disposed to illuminate said cell, the other of said elements comprising a nonmagnetic shield disposed to control the passage of light between said source and said cell in accordance with the position of said car in said hatchway, means for mounting said magnetizing and said cell elements on said car in substantially the same vertical line, means for mounting said magnetizable and said light-controlling elements in said hatchway at predetermined points in substantially said same vertical line for cooperation with said car-carried elements, and means to prevent operative cooperation between said cell element and said magnetizable element, whereby said sets of contact members may be selectively operated at different points with small lateral space requirements of said operators.

20. In an elevator leveling control system, an elevator oar operable in a hatchway past a floor landing, tip-leveling mechanism and down-leveling mechanism, each of said leveling mechanisms having first and second elements, means for mounting said first elements in said hatchway, means for mounting said second elements on said car for movement into cooperative relation, re-

, spectively, with said first elements when said car is substantially level with said landing, and means rendered effective upon said elements of one of said mechanisms being moved out of cooperative relation to cause said car to move in i the corresponding direction, regardless of the relative positions of the elements of said other mechanism during such movement.

21. In an elevator control system, an elevator car operable in a hatchway past a landing upleveling connections, down-leveling connections, means effective while said connections are complete, respectively, to cause said car to move in the corresponding direction, up-leveling mechanism and down-leveling mechanism for controlling the leveling connections, each of said mechanisms having first and second elements, means for mounting said first elements in said hatchway, means for mounting said second elements on said car for movement into cooperative relation, respectively, with said first elements when said car is substantially level with said landing, and means rendered effective upon the elements of one of said mechanisms being moved out of cooperative relation to cause completion of the corresponding connections until said elements are again brought into cooperative relation, regardless of the relative positions of the elements of said other mechanism during such movement.

22. In an elevator control system, an elevator car operable in a hatchway past a landing, leveling connections, means responsive to completion of said leveling connections to cause said car to start and responsive to interruption of said leveiing connections to cause said car to stop, a first leveling mechanism and a second leveling mechanism for controlling the leveling connections, each of said mechanisms having main and cooperating elements, means for mounting one element of each of said mechanisms in said hatchway, means for mounting the other elements of each of said mechanisms on said car in such positions that the elements of said first mechanism are brought into cooperative relation when said car is one distance in advance of said landing and the elements of said second mechanism are brought into cooperative relation when said car is a greater distance in advance of said landing, means rendered effective upon the elements of said first mechanism being moved out of cooperative relation to cause completion of said leveling connections, means adapted upon the elements of said second mechanism being moved out of cooperative relation to interrupt said leveling con nections, and additional means operable to prevent interruption of said leveling connections by said last-mentioned means.

23. In an elevator control system, an elevator car operable in a hatchway past a landing, leveling connections, means responsive to completion of said leveling connections to cause said car to start and responsive to interruption of said leveling connections to cause said car to stop, a first leveling mechanism and a second leveling mechanism for controlling the leveling connections, each of said mechanisms having main and 00- operating elements, means for mounting one ele ment of each of said mechanisms in said hatchway, means for mounting the other elements of each of said mechanisms on said car in such positions that the elements of said first mechanisms are brought into cooperative relation when said car is one distance in advance of said landing and the elements of said second mechanism are brought into cooperative relation when said car is a greater distance in advance of said landing, means rendered effective upon the elements of said first mechanism being moved out of cooperative relation to cause completion of said leveling connections, means adapted upon the elements of said second mechanism being moved out of cooperative relation to interrupt said leveling connections, a closure associated with said elevator, and means controlled by said closure to prevent interruption of said leveling connections by said last-mentioned means.

24. In an elevator control system, an elevator car operable in a hatchway past a landing, leveling connections, means responsive to completion of said leveling connections to cause said car to start and responsive to interruption or said leveling connections to cause said car to stop, a first leveling mechanism and a second leveling mechanism for controlling the leveling connections, each of said mechanisms having main and cooperating elements, means for mounting one element of each of said mechanisms in said hatchway, means for mounting the other elements of each of said mechanisms on said car in such positions that the elements of said first mechanism are brought into cooperative relation when said car is one distance in advance of said landing and the elements of said second mechanism are brought into cooperative relation when said car is a greater distance in advance of said landing, means rendered effective upon the elements of said first mechanism being moved out of cooperative relation to cause completion of said leveling connections, means adapted upon the elements of said second mechanism being moved out of cooperative relation to interrupt said leveling connections, a closure associated with said system, and means efiective while said closure is closed to prevent interruption of said leveling connections by said last-mentioned means.

25. In an elevator control system, an elevator car operable in a hatchway past a landing, leveling connections, means responsive to completion of said connections to cause said car to start upwardly and responsive to interruption of said connections to cause said car to stop, up-leveling mechanism and down-leveling mechanism for vcontrollling the leveling connections, each of said mechanisms having first and second elements, means for mounting one element of each of said mechanisms in said hatchway, means for mounting the other element of said up-mechanism on said carin such positions that said elements of that mechanism are in cooperative relation when said car is in a predetermined region below said floor, means for mounting the other element of said down mechanism on said car in such position that said elements of that mechanism are in cooperative relation when said car is in a. greater predetermined region below said floor, means rendered efiective upon the elements of said up mechanism being moved, by downward movement of said car, out of cooperative relation to cause completion of said connections, means adapted upon the elements of said down mechanism being moved, by downwardmovement of said car out of cooperative relation to interrupt said connections, and additional means operable to prevent interruption of said connections by said last-mentioned means.

26. In an elevator control system, an elevator car operable in a hatchway past a landing, leveling connections, means responsive to completion of said connections to cause said car to start downwardly and responsive to interruption of said connections'to cause said car to stop, downle'veling mechanism and up-leveling mechanism for controlling the leveling connections, each of said mechanisms havingfirst and second elements, means for mounting one element of each of said mechanisms in said hatchway, means for mounting the other element of said down mechanism on said car in such positions that said elements of that mechanism are in cooperative relation when said car is in a predetermined region above said fioor, means for mounting the other element of said up mechanism on said car in such position that said elements of that mechanism are in cooperative relation when said car is in a greater predetermined region above said floor, means rendered effective upon the elements of said down mechanism being moved, by upward movement of said car, out of cooperative relation to cause completion of said connections, means adapted upon the elements of said up mechanism being moved, by upward movement of said car out of cooperative relation to interrupt said connections, and additional means operable to prevent interruption of said connections by said lastmentioned means. I

27. In an elevator control system, an elevator car operable in a hatchway past a landing, leveling connections, means responsive to completion of said connections to cause said car to start upwardly and responsive to interruption of said connections to cause said car to stop, up-leveling mechanism and down-leveling mechanism for controlling the leveling connections, each of said mechanisms having first and second elements, means for mounting one element of each of said mechanisms in said hatchway, means for mounting the other element of said up mechanism on said car in such position that said elements of that mechanism are in cooperative relation when said car is in a predetermined region below said floor, means for mounting the other element of said down mechanism on said car in such position that said elements of that mechanism are in cooperative relation when said car is in a greater predetermined region below said floor, means rendered effective upon the elements of said mechanism being moved, by downward movement of said car, out of cooperative relation to cause completion of said connections, means adapted upon the elements of said down mechanism being moved, by downward movement of said car out of cooperative relation to interrupt said connections, a closure associated with said system, and means controlled by said closure to prevent interruption of said connections by said lastmentioned means.

28. In an elevator control system, an elevator car operable in a hatchway past a landing, leveling connections, means responsive to completion of said connections to cause said car to start downwardly and responsive to interruption of said connections to cause said car to stop, downleveling mechanism and up-leveling mechanism for controlling the leveling connections, each of said mechanisms having first and second elements, means for mounting one element of each of said mechanism in said hatchway, means for mounting the other element of said down mechanism on said car in such positions that said elements of that mechanism are in cooperative relation when said car is in a predetermined region above said floor, means for mounting the other element of said up mechanism on said car in such position that said elements of that mechanism are in cooperative relation when said car is in a greater predetermined region above said floor, means rendered effective upon the elements of said down mechanism being moved, by upward movement of said car, out of cooperative relation to cause completion of said connections, means adapted upon the elements of said up mechanism being moved, by upward movement of said car out of cooperative relation to interrupt said connections, a closure associated with said system, and means controlled by said closure to prevent interruption of said connections by said lastmentioned means.

29. In an elevator control system, an elevator car operable in a hatchway past a landing; first leveling connections, second leveling connections, means responsive to completion of said first connections to cause said car to travel at a certain speed, means responsive to completion of said second connections to cause said car to travel at a higher speed; a first leveling mechanism and a second leveling mechanism for controlling the leveling connections, each of said mechanisms having first and second elements, means for mounting one element of each said mechanisms in said hatchzvay, means for mounting the other elements of said mechanisms on said car in such positions that the elements of said first mechanism are brought into cooperative relation when said car is a certain distance in advance of said fioor and the elements of said second mechanism are brought into cooperative relation when said car is a greater distance in advance of said landing, means rendered effective upon the elements of said first mechanism being moved out of cooperative relation to cause completion of said first connections, and means rendered effective upon the elements of said second mechanism being moved out of cooperative relation to cause com pletion of said second connections.

80. In an elevator control system, an elevator car operable in a hatchway past a landing; first leveling connections, second leveling connections, means responsive to completion or" said first con- "-ections to cause said car to travel at a certain speed, means responsive to completion of said second connections to cause said car to travel at a higher speed; a first leveling mechanism and a second leveling mechanism for controlling the leveling connections, each of said mechanisms having first and second elements, means for mounting one element of each of said mechanisms in said hatchway, means for mounting the other elements of said mechanisms on said car in such positions that the elements of said first mechanism are in cooperative relation While said car is in a region extending one distance below said floor and a greater distance above said fioor and the elements of said second mechanism are in cooperative relation while said car is in a region extending said one distance above said floor and said greater distance below said floor; means, rendered effective upon the elements of said first mechanism being moved out of cooperative relation, by downward car movement, to cause completion of said first connections and, by upward car movement, to cause completion of said second connections; and means, rendered effective upon the elements of said second mechanism being moved out of cooperative relation, by upward car movement, to cause completion of said first connections and, by downward car movement, to cause completion of said second connections.

31. In an elevator control system, an elevator car operable in a hatchway past a floor landing, means to control said car including up-leveling connections and down-leveling connections means responsive to completion of said connections, respectively, to cause said car to start in the corresponding direction and responsive to interruption of said connections to cause said car to stop, mechanism associated with said up-connections and mechanism associated with said down-connections for controlling said connections, each of said mechanisms having first and second elements, said first elements including u light sensitive cell, said second elements including means to effect, respectively, predetermined different conditions of illumination of said cells when in corresponding predetermined positions with respect thereto, means for mounting one element of each of said mechanisms on said car, means for mounting the other elements of each of said mechanisms in said hatchway in such positions that the associated cell is subjected to one of said predetermined conditions of illumination when said car is substantially level with said landing; and means comprising switching mechanism responsive to that condition of illumination of said cells to interrupt said leveling connections and responsive to another of said conditions of illumination of either of said cells to cause completion of the leveling connections associated with that cell, said switching mechanism comprising interlocking means associated with each cell and disposed to prevent completion of the connections associated with the opposite direction of movement, and means effective upon completion of the leveling connections associated with either of said cells to render the interlocking means associated with the other of said cells ineffective.

32. In an elevator control system, an elevator ear operable in a hatchway past a floor landing, means to control said car including up-leveling connections and down-leveling connections, means responsive to completion of said connections, respectively, to cause said car to start in the corresponding direction and responsive to interruption of said connections to cause said car to stop, mechanism associated with said up-connections and mechanisms associated with said down-connections for controlling said connections, each of said mechanisms having a light sensitive cell element, and an element adapted to effect predetermined difl'erent conditions of 11- lumination of said cell when in corresponding different positions with respect thereto, means for mounting said cell elements on said car, means for mounting said other elements in said hatchway in such positions as to subject the associated cells to one of said conditions of illumination when said car is substantially level with said landing, means including switching mechanism responsive to the condition of illumination of said cells, and effective, while said cells are subjected to said one condition of illumination to cause interruption of said leveling connections, and effective, upon movement of said car to a position in which one of said cells is subjected to another of said conditions of illumination to cause completion of the associated leveling connections, said switching mechanism comprising interlocking means associated with each cell and disposed to prevent completion of the connections associated with the opposite direction of movement, and means elfective upon completion of the leveling connections associated with either of said cells to render the interlocking means associated with the other of said cells ineffective.

33. In an elevator control system, an elevator car operable in a hatchway past a floor landing, means to control said car including up-leveling connections and down-leveling connections, means responsive to completion of said connec-

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