USRE15125E

USRE15125E - lindquist and f

Info

Publication number: USRE15125E
Authority: US
Publication date: 1921-06-14

Description

D. L. LINDQUIST AND F. HYMANS.

ELEVATOR.

APPLICATION FILED OCT. 30, I920.

Reissued June 14, 1921. v 15,125.

3 SHEETS-SHEET I.

L I nae/lions.

3 SHEETS-SHEET 2.

ELEVATOR.

APPLICATION FILED on. 30. I920.

D. L. LINDQUIST AND F. HYMANS.

Reissued June 14 1921.

fume/Zions: K

D. L. LINDQUIST AND F. HYMANS.

ELEVATOR.

APPLICATION FILED on. 30. 1920.

Reissued June 14, 1921.

exact landing of a load car ,vioe adapted to be ope UNITED STATES PATENT OFFICE.

DAVID L. LmDQUIST, OF YONKERS, NEW YORK, AND FRED ERICK -mA.N'S, 01'

I ELEVATOR.

To all whom it may concern:

Be it known that we, Davin L. LiNo UIs'r, residing in Yonkers, in the county of Westchester and State of New York,- subject of the King of Sweden, and FREDERICK in Glen Ridge, county of Essex, State of ew Jersey, cltizen of the Netherlands, have invented a new and useful Improvement in Elevators, of which the following is a specification.

Our invention relates in general to load car ing devices, and is directed more particu arly to an electrically controlled elevator or hoist.

An object of the invention is the provision of automatic means for eifecting an ing device such as an elevator car, at a re etermined point or points regardless of t e load and speed of the device.

Other objects of the invention will appear hereinafter, the novel combinations of elements being pointed out in the appended claims.

In the drawings accompanying this specification, Fi re 1 represents in elevation view one em iment of our invention; Fig. 2 is an'end view of Fig. 1; Fig. 3 is a sectional view of the combined friction brake and coupling shown in Figs. 1 and 2; Fig. 4 is an end view of Fig. 3 shown in part section; Fig. 5 is a wirin diagram of a system, of direct current e ectrical circuits which may be used in carrying out our in vention.

Like reference characters denote similar parts in all of the figures.

Generall speaking, our invention comprises an e evator or other load ca ing derated at ifi'erent speeds by means of different motors, and means for automatically transferring the load from one motor to another motor as the load carrying device approaches its stopping int.

Itas long been recognized that one of the means for effecting an accurate stop of an elevator car at a landing or other stopping point consists in reduci lll g the speed before reaching the same. is reduced HYMAN residingI speed in order to be effective must be independent of the load and should be a small speed of the car I Specification o1 Reissued Letters Patent. Rei d J 1 1921 Original 10. 13883 27, dated November 5, 1918, Serial Io. 64,396,

for reissue llled October 80, 1920. Serial filed December 1, 1915. Application No. 420,840}.

fraction of the normal or full speed. a single motor is used for hoisting pur oses, it is practically impossible to effect su cient speed reduction w ere a high degree of accuracy 1n stopp1ng is ulred, and this is true partlcularly when tlie elevator car is operated by an electric motor at high speed under a wlde variation in load. By reason of our invention we are enabled to reduce the to any desired predetermined low speed ust before making a landng so as to insure an accurate or exact landng regardless of the load and also resultin in other advantages which will be pointed 0111!} later on. se to any hoisting apparatus, it is rticularly adapted to an automatically coiit rolled 61%!8201'. h

e erring to t e drawin the articular embodlment of our inventfin thei ein illustrated comprises a' cable sheave or winding drum A which in the present instance is operatively connected through the worm gearing to an electric motor C although the motor and sheave A could be directly connected if so desired. The gearing B is also connected through a combined clutch and brake D and worm gearing E to an additlonal electric motor F having a brake G associated therewith. The motors C and F may be of any desired kind of power units such for example as alternating or direct current electric motors, the latter type of motor being shown by way of illustration with a view to simplicity.

The combined brake and clutch D which operates to slow down the hoisting drum and permit a transfer of the load from the main motor C to the auxilia motor F, is shown in detail. in Figs. 3 an 4, and comprises a ir of brake shoes 1, 1, adapted frictional y to engage a brake pulley 2 secured on the shaft 3 of the motor 0. Each brake shoe is carried by a corresponding lever 4 pivoted at 5 to the frame 6, the other end of each lever 4 being acted upon by compression spring 7 tending to force the shoes into frictional braking engagement with the pulley 2. In order to release the brake shoes from the pulley 2, we provide a pair of bell crank levers 8, 8, pivoted at 9 to the frame 6, the vertical arm of each lever terminating While the invention lends itin a rounded nose 10 in horizontal alinement.

with a sliding rod 11, while the horizontal 12, 12. The frame 6 1s journa ed in the gear casing 13 and carries a worm Wheel 14 mesh ing with a worm 15 secured to the shaft 16 of the auxiliary motor F shown in Fig. 2." 'An elect omagnet 18 is arranged to operate the levers 8, 8, to effect the releaseof the brake shoes 1, 1, andthe same comprises a fixed and movable magnet core 17 and 19, respectively, the latter, being connected to one arm of a bell crank lever 20, while the otherarm of this lever carries an-admstable screw 21 coacting with theslidmg rod 11. The 0 eration of theapparatus. is as follows: Wlien all parts are at rest, the magnet 180i the combined brake and clutch D is deenergized and the brake shoes 1, 1, are applied thus coupling the wmdmgdrumi A up to the auxiliary motor F which is prevented from. accidental rotation by reason of the brake G which is applied at this time. The first step in the operation is to excite the magnet 18 to release the brake shoes 1, 1,

and to close a circuit to the main motor C.

This resultsin severing all connection between the hoisting drum and the auxiliary motor F, and allows the motor C to startthe load, and after a short period of acceleration,

operate the latter at full normal runnin drive the auxiliary motorthrough the gearing E, but themotor F will not rotate at this time, since it is revented from doing so by the brake G. is efl'ect therefore of the brake clutch D is that of an ordinary friction brake which would eventually bring the hoistin apparatus to rest. 'When the speed of the atter has been reduced to a suflicient extent, the brake G and the motor F are energized and the latter drives the load at a very low speed since the motor F acts on the load through a double gear reduction comprising the worm gearing E and B. This slow speed is a constant speed regardless of the load and is maintained until the load substantially reaches the landing whereupon the circuit to motor F is interrupted and the brake G applied to stop and hold the load exactly at the landing.

It will be observed that when the load carrying device is being driven at slow speed by the auxiliary motor F, the maximum torque which can be exerted upon the hoisting drum is limited to the friction existing between the brakeshoes, 1, 1, and the'pulley 2. This feature is of great practical value particularly in the case of inclined railways chinery or other arts, w

or ammunition hoists having a positive or head-on landing stop. Under the usual practice, failure to stop at-the proper-instant is almost certain to'damage the hoisting maereas by means of our invention t e stopping point is approached at a very low speed and even though the auxiliary motor should not be i cut 0 from the source of power at the proper instant the brake shoes 1, 1, would merely slip upon the pulley 2. With proper design the torque transmitted by the brake clutch D. may'easily be kept within limits which will not permit excessive strains on the hoisting, apparatus or other parts in caseof overf run. I

Referring to Fig. 5, we show a system of direct current circuits which maybe used where the main and auxiliary motors C and F, respectively, are direct current shunt carrying device adapted automatically to be operated by push buttons arranged .in the car and at each floor landing. R and R designate the switches for starting, stop ing and reversing the main motor C while I is a starting resistance automaticallv controlled the accelerating magnet J. he parts 1', 1- K and J in like manner control the starting, stopping, reversing and accelerating respectively, of the auxiliary motor F. i represents a floor controller which is operated by some moving part of the hoisting, a paratus such as the winding drum in t e usual way, and the same, actmg in conjunction with the relay L, effects the transfer of. theload from the main to the auxiliary motor at the proper timein accordance with the position of the car with respect to a desig 105 nated floor landing or other stopping point. 1 If desired the floor controller may comprise a series of switches the hatchway operated by the car or counterweight either arrangement of floor controller being well known in 110 i the art. As indicated on the drawing, the

s stem of push buttons is arranged for three oor landings and the car is at rest at the second floor.

Theoperation is as follows A person-on 1 15 "the ground floor desiring to use the elevator,

presses the button 22 at that floor. This establishes a circuit from the main.

through the door contacts 23, through the reversely woundmagnet coils of the magnet 1120 24, contacts 25, push button 22, winding of the floor relay 26, to the contact 27 of the floor controller I, The circuit continues through the segment28 and contact 29 to the winding of the reversin completed by way of t e conductor 30 to the main.- The reversing switch R and floor relay 26 both operate to close their respective contacts, the switch R closing circuitsto the motor C through the starting m- 130 wound electric motors. In this figure, H represents an elevator car or other load switch R and is sistance K, and simultaneously opening any possible circuitto the auxiliary motor through the bottom contacts of the switch as long as the switch is in raised position. 'The operation of the relay 26 establishes a self holdin v circuit comprising the left hand winding of the magnet 24 and resistance 31, this circuit being in shunt to the circuit including the contacts 25 and the ash button 22. In consequence of this self ioldin circuit, the contacts 25 become separatell and hence the other floor buttons are rendered dead and there can be no interference in the operation in case another of the buttons be operated. As the motor starts to build up a counter-electro-motive force, the accelerating magnet automatically and gradually short-circuits the starting resistance J in a well-known way and the motor quickly runs up to full normal speed. In the meantime the relay L having its operating magnet connected in direct shunt to the main motor armature separates its contacts 32.

It will be observed that the closing of the reversing switch R completes a circuit to the magnet 18 of the brake clutch D at the contact 34, hence the brake shoes 1, 1, are re leased from frictional engagement with the pulley 2 and the auxiliar motor F is entirely disconnected from t 1e hoisting apparatus.

The main motor continues to operate the hoisting ap aratus at full speed while the floor contro ler is slowly being revolved in a clockwisedirection until finally as the car approaches the ground floor, the contact 27 of the floor controller brid es the segment 28 and contact 35. A circuit in parallel to the magnet'of the reversing switch R is now closed, said circuit comprising the contact 35, segment 36, contact 37, and the winding of the reversing switch 1'. The latter at once closes its contacts to establish the roper connections for the auxiliary motor and brake G but neither of them as yet receives current from the main line since their circuit is still open at the contacts 32 of the relay L and also at the bottom contacts of the reversing switch. As .the floor controller continues to revolve, the contact 27 runs off of the segment 28 and hence the circuit to the reversing switch R is interrupted and the switch drops its contacts thereby opening the circuits of the main motor C and the circuit to the winding 18 of the brake clutch D. The latter now acts as a brake on the hoisting apparatus and the speed of the car is gradually reduced. As the s )eed of the motor C falls off, its counter-electro-motive force becomes less and less until finally the relay L is unable longer to maintain its core in raised position and the contacts 32 are connected tother. The circuit to the auxiliary motor and brake G is now completed at these contacts and the motor F automatically takes up the load and operates it at greatly reduced speed. Just. as the load reaches the landing, or in an instant before, as the case may be, the floor controller rotates the contact 35 out of engagement with the contact 27, and the circuit, including the floor re lay 26 and reversing switch 1'' is interrupted at this point. The switch r immediatel opens the circuit of the auxiliary motor 1 and effects the application of the brake G to stop the hoist exa'ctl at the floor landing.

If one or the other landing push buttons be operated, the car will automatically respond and come to rest at the corresponding floor landing just as in the case of the button 22 just described, the floor controller I automatically controllin both of the motors in every lnstance in oth directions of car travel.

The operation from one of the push buttons in the car is in effect the same as that produced by a floor button although the operating circuit is somewhat dilferent. For example, upon pressing the button 22' in the car, a circuit is closed from the main through the door contacts 23, left hand winding of the magnet 24, wire 38, winding of magnet 39, through the push button 22 floor relay 26, contacts 37 and 29 of the floor controller and through the reversing switch magnet it to the main. The magnet 24 immediately so arates the contacts 25 to prevent an inter erence from the floor buttons, while t e ma 'net 39 closes its conmm; to establish a self holding circuit for both of the magnets 24 and 39 including the door contacts 23 and resistance 40. This self holding circuit is maintained after the floor controller has effected the stop of the car at the designated floor landing and is not broken until the landing door has first been opened, thereby opening one of the door contacts 23, and the door then closed. This safety feature prevents any operation from a floor button unless and until the operator in the car has first restored the system to initial position by opening and then closing a door.

In reviewing the operation, it will be observed that the load is transferred from the main motor to the auxiliary motor only after the speed of the 'car has been very materially reduced, and in every case the amount of speed reduction is Ipredetermined and controlled b the relay The latter may readily be esigned or adjusted in any of the well known ways, such for example as by means of a set screw 41, to short circuit its contacts at any predetermined speed reduction of the motor so as to obtain the best results in practice. While the relay L supplies a simple means for determining when the auxiliary motor will take hold of the load, it is obvious that any other device 50 v '1 at constant speed with varying loads.

Y responsive to speed conditiomsuch for ex- It is desirable that or load carryin device shall first be reduced to'a speed'su stantially the samepas the ample asa centrifugal governor,would efiect a'slmilar' result.

speed of the car normal speed of the auxiliary motor before theciricuit' to the latter is closed and its brake G released in order? that the auxiliary motor may takeupjthe load without any shock or 'ar, In some 'cajsesit'may be desired to e ecta fullstop'oflthe load carryin device before a landingisreac'hed and beiore the auxiliary motor is brought lnto operation. This may readily be done merely adjusting the relay L or other speed responsive device so that it will not establish the auxiliary motor circuit until the main motor has either completely or substantially come to rest. i

In order that the load carrying device shall invariably stoplevelfwith a floor or exactly at a given point. inits travel, it

is essential that the speed be substantially reduced before the stopping point is reached and that the load from then on shall be operated at a constant low speed re gardless of the'loadL; TlllS necessitates a constant speed auxiliary motor regardless of what type it may be. In the. particular embodiment of our invention this motor is so when the resistance of the motor armature represented as a shunt; wound direct current electric motor operating directly across the line, and it is'well "known that it is the] inherent characteristic of such a motor to run at afixed speed even though the load varies within wide limits" and particularly ismade as low as possible. If an alternating current induction motor is used in place of a direct current motor, the system of electric circuits wouldjof course have to be modified somewhat so as .to be adapted -to that type of motor, but the alternating current motor will operateat constant speed.

' even though the load varies, since such motor is inherently a constant speed motor.

Other motors, such as steam, hydraulic, etc.,

could also be used providing they be suitably governed as is customary so as to operate In any event, it is intended that the aux a iliary motor be arranged to operate the load at a comparatively low speed, whereas the main motor may operate the load at any speed desired.

From the foregoing, it is obvious that the a paratus disclosedis capable of being modi ed in many ways without departing from the spirit and scope of our invention,

1 andtherefore we desire not to be limited to the precise construction and arrangement of arts herein set forth. a

hat we claim is: k y, i y

1; In an elevator,"the combination of a other motor as: the car" approaches a prede;

termined stopping point.

3. In an, elevator, the combination of a car, two motors operatively connected therewith, and means dependent upon the position of the'car with; respect to a predetermined point in its travel and upon its speed for transferring the load from one motor to the other. I

4. In an elevator, the combination of a car, a motor connected therewith, automatic means for retardingsaid motor as the car approaches a predetermined stopping point, and an additional motor adapted to be connected to drive the, car at:a constant slow speed after the speed, of the latter has been reduced a predetermined amount.

5. In an elevator, the combination of a car, a motor connected to drive the car, means for retardinggthe speed of said motor as the car approachesa predetermined stopping point, a second motor, adapted to be operativelyconnected to the'car' upon the operation of said motor-retarding means, and means dependent on. the speed of the car for. automatically controlling said second motor, :2 i v 6.,In an elevator, the combinationv of a .car, a motor connected to drive the car,

means, for retarding the speed of said motor as the car approachesa predetermined stopping point, a second motor adapted to be operatlvely connected to the can upon the operation of said motor-retardin means, and means dependent on the s e of the car for automatically starting sald second motor.

7. In an elevator, thecombination of two car, main and. auxiliary hoisting -motors electric hoisting motors-and means for closing the line circuit to onesof said motors in accordance with the counter-electro-motive force of theother motor.

8. In an electric elevator, the combination of two hoisting motors, means for disconnecting one of the said motors from the car upon startin thecar, and means for again connecting t e said motor and car after the speed of the other motor has been reduced a predetermined amount.

9. In an electric elevator, the combination of two hoisting motors, electro-responsive means. for disconnecting oneof the said motors. from the carupon starting the car and for again connectin the said motor andcar after the speed of t e other motor has been reduced apredetermined amount.

10. In an elevator, the combinationof an electric hoistin motor adapted to drive the car at normal glll speed, an additionalelectric motor adapted to drive the car at a reduced speed, an electrically controlled friction clutch between said additional motor and the car, electro-responsive means for simultaneously releasing said clutch and closing a circuit to the motor for full speed operation of the car, automatic means for applying said clutch and interrupting the circuit of said last named motor as the car approaches a redetermined stopping point, means dependent for its operation upon a predetermined speed reduction of the car for closin a circuit to the additional motor whereby tie latter operates to drive the car at reduced speed, a brake for the additional motor, and means for interrupting the circuit of said additional motor and applying the brake to stop the car at the predetermined stopping point.

11. In an elevator stem, comprisi a car, hoisting cables, hoisting motor mec nism, and a brake pulley and shaft therefor to operate the car, a revolving pressure means, comprising a shaft and lever,-to con- .nect the car and the said motor mechanism together, the said shafts being separate and a stationary releasin means to release the pressure means to isconnect the car from the motor mechanism.

12. In an elevator system, comprisin a car, hoisting cables, hoistin motor mec am'sm, and a brake pulley ang shaft therefor to operate the car, a revolving pressure means, comprising a shaft and lever, to connect the car and the said motor mechanism together, the said shafts being separate, and a stationary releasing means, comprisin a. lever, to release the pressure means to isconnect the car from the motor mechanism.

13. In an elevator system,--comprising a car and main and auxiliary hoisting motors, a brake pulley and shaft therefor, a revolving pressure means, comprising a shaft and a lever, to connect the-car and the auxiliary hoisting motor to ther, the said shafts being separate, and a stationary releasing means, to release ,the pressure to disconnect the car from the auxillaryhoisting motor.

14. In an elevator system, comprising a 15. In an elevator system, comprising a car andmain and auxiliary hoisting motors, a brake pulley and shaft therefor, a revolvin pressure means, comprising a shaft and a fiver, to connect the car and the auxiliary hoisting motor together, the said shaftsbeing separate, an a stationary releasing means, comprising a lever to release the pressure means to disconnect the car from the auxiliary hoisting motor, and connections between the said pressure and releasin means.

11 testimony whereof we have signed our names to this specification this 27th day of October, 1920.

DAVID L. LINDQUIST.

FREDERICK HYMANS.

ther, the said. shafts be- 60