US848372A - Electric hoisting system. - Google Patents

Description

. PATENTED MAR. 26, 1907. J. D. IHLDER & R. W. SCOTT.

ELECTRIC HOISTING SYSTEM.

APPLICATION FILED JULY 29, 1905.

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' ATTORNEY WITNESSES:

1 PATENTED MAR. 26, 1907. J. D. IHLDER & R. W. SCOTT.

ELECTRIC HOISTING SYSTEM.

APPLICATION FILED JULY 29, 1905.

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Jonson-moan, or r w YORK, N. Y., AND RUMSEY W. SCOTT, or WASH- l: INGTON, DISTRICT OF COLUMBIA, ASSIGNORS TO OTIS ELEVATOR COMPANY, OF JERSEY- OITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELECTRIC HoisTme SYSTEM.

Patented March 26, 1907.

To all whom it may concern.-

' i Beit'known. that We, JOHN D. IHLDER, residingat New York city, in the county of New Yorkand State of New York, and Runsny'w. Scor'r, residing at Washington, .District'of- Columbia, citizens of the United States, have jointly invented a new and useful Improvement in Electric Hoisting Systems, of which the following is a specification.

Our invention relates to those classes of hoisting apparatus which are electrically operated, and has for its object the provision of a self-locking device near the upper limit of travel'of a car or carrier for preventing the carjromfalling should the hoisting apparatusbecome ino erative, and electric means for actuating said self-locking device so that the car ma descend when desired, in combination' wit means for automatically slowing down the speed of the car or carrier as it approaches its upper limit of travel and for electrically holding the same at that point through the action of an electric motor connected to drive the hoisting apparatus, and

for automatically slowing down said car in accordance with the load as it approaches its lower limit of travel.

\Other objects will appear hereinafter, the

novel combinations of parts being set forth in the claims.

In the accompanying drawings, Figure- 1 represents diagrammatically the motor-controlling apparatus and latch device embodied 1n our invention, and Fig. 2 represents an electric elevator system to illustrate an application of the invention.

Referring now articularly to Fig. 1, 1O designates a mainine switch connecting the apparatus to the source of current-supply, (designated by the characters and 20 designates a manually-operable switch. 30 is a magnetic locking device, and 26 designates an electromagnet which serves to c0mplete, a circuit through the hoisting-motor. 40 designates what we call the load-magnet and serves to operate the movable contacts 42, 43, and 44, and thus control the resistances 37, 38, and .39. is an electronmgnet controlling the resistance :32. is an accelerating-magnet which controls the various: movable contacts shown directly under it, these contacts being connected to the several resistances 33, 34, 35, &c. 47 designates an electromagnet controllingthe movable contact 48. is the hoisting-mo tor, whose field is shown at 61, 62 being the motor-armature and 63 and 64 the armaturebrushes. is an automatic stop-motion switch and comprises a number of circularlysha ed contact-strips, such as 79, 91, 93, &c., an insulating-pieces 80, 81', 92, 97, 98, &c. These are mounted on some insulating material, such as slate, and the whole is rotata- -bly mounted and is preferably connected by The main switch 10 being in the position shown on the drawingsthat is, closed-the contact-strip 14 of the switch 20 will be con nected to theor negative main of the supply of current. piece 15 is always in contact with the stri '14 and is pivoted at the center 18, about w ich it may be moved by means of the arm 1 6 and handle '17. If the latter be moved toward The segmental contact? the left, the contact-piece 15 will engage the contacts 1 and 2. Now 1 and 2 are connected by wires to the contact-brushes $4 and 85, respectively, on the automatic stopmotion switch 75. The brushes l-"and 85 are shown connectedto the brushes 86 and 87 by the contact-strips 91? and 9 5, res ect-ively. The brush 86 is one terminal 0 the circuit for the brake-magnet 66. The other terminal of this magnet is connected by wires 73 and 11 to the or positive main. The brake-magnet 66 will now receive current and by means of the toggle 68 will overcome the action of the spring 67, and thus move the brake-bands 71 from the frictionpulley 69, allowing the latter to turn freely. Atthe same timethe brush 87 s connected to the brush 85 by contact-strip 95, and since brush 87 is connected to one terminal of'the magnet 26, whose other terminal 18 connected to the positi e-mam by wire 11, the

motor will now start at slow speed, the brake having been released. On further moving the handle 17 to the left the contact-piece will engage the fixed contact This con- "tact is connected by wire to the brush 83, which is in electrical connection with the brush 88 through contact-strip 94. New 88 is connected to one terminal. of the magnet 45, whose other terminal is connected by wire 29 to the positive main when the contacts 27 have been operated. 45 will now be energizcrl, being connected across the mains, and the contacts 46 will be brought together. This operation will cause the resistance 32 to be SllOIlZrClIClliliGtl and the motor will now receive more current and run at a faster speed. The next operation of the switch is when the handle 17 has been placed in its extreme left-hand position, energizing the contact 4, which is connected, through the automatic stop-motion switch 75, to one terminal of the aecelcrating-magnet 50. of this magnet 50 is connected by wires 1'01 and 49 to one of the armature-brushes. Thus the magnet 50 is connected across the motorarmature and will operate automatically to cut out or short-circuit the accelerating resistances 33, 34, 35, and 36 consecutively in.

a well-known way depending upon the load on the motor.

One terminal of the magnet 47 is connected to the insulated contact 55 and as soon as the magnet 54 has been operated by the magnet 50, 55 will engage 56, which has already been connected to the positive line through wires 31 29, contacts 27, and Wire 11. The other terminal of magnet 47 is connected, through the. automatic stop-motion swatch and operating-switch 20,- to the wire 13, which is connected to the negative main. 'lhcrcl'orc soon as the contact 55 engages contact 56 the magnet 47 will be energized and operate contacts 48, causing the resistance 36" to be cut out or short-circuilcd. The motor-armature now receives currcnt at the lincpotential and can run up to full speed to drive the car or carrier iii an upward direction. The automatic stop-moiion switch 75 has in the meanwhile slowly revolved in a clockwise direction, being drivca, as before pointed out, by the hoisting machinery. As the car or carrier approaches its uppcr limit the first operation of the switch 75 will be when the contact-brush 82 runs onto the insulating-piece 9.). This will cause the magnets 50 and 47 to become dccncrgizcd, since their currcnt supply is inter- The other terminal 2 6, 40, 45, 50, and-47.

rupted at the brush 82. 1 This will operate to replace the resistances 33, 34, 35, 36,and 36 back into the armature-circuit, which will cause the motor to immediately slow down.

Very shortly after this operation has taken place the contact-brush 83 runs onto the insulating-piece 98. This causes the magnet to the circuit 45 to-be broken, causing to drop its contact and replace the resistance 32 in the armature-circuit, causing the motor to 1 run at a very slow speed, the current to the motor-armature being very materially reduced on account of having replaced all of the starting resistance in series with the armature. The car or carrier is now brought up against the buffer at the top of its runthat is, to the" desired upward limit of its travel. The current which is still being applied to the mot-or is of suflicient strength to cause the load to be held against the buffer, but it is not sutficient to injure the motor armature.

In Fig. 2 we have illustrated more or less diagrammatically an elevator "system including a hoisting-drum 103, hoisting-cables 100, counterweight 1V, and a car C. The floorcontroller is shown connected by-sprockets and sprocket-chain to the hoisting-drum.

On the controller-board 105 are mounted the main-line switch 10 and the electromagnets The latch device 30 may have its fixed pivot of course connected to some rigid support in any well-known manner. At or near the upper limit of the travel of the car or carrier, as shown 1n Fig.

2,is.a self-locking device 30, which is so constructed that it allows a movement 'ofsome, part, as 25, of the carrieror car C a short d1stance past the latch 24, but will prevent or hold the carrier from movement in a down-' ward direction past said latch until said latch is released by means of the electromag.

net 102. This self-locking mechanism, there;

fore,-constitutes a safety device to prevent the carrier from falling ordescending below the same when not desired if the hoistingcables should break or the electrical holding means become inoperative,

When it is desired to lower the car or carrier, the switch-handle 17 is brought back to its central position, as shown on the drawings. This will cause the brake to be applied, as the circuit to the magnet 66 is broken at the contact Furthermore, the circuit of magnet 26 is interrupted at the contact 2, and there fore the contacts 27 are opened. The current to the motor is thus cut oil, and the carrier could descend by reason of its own load, but is held from doing so by the latch 24. and the brake; On moving the handle 17 to the right, however, the contact 15 will engage with the fixed contactsfi and. 6. A circuit will then be closed through the magnet 102 from the positive main, through wires 11. and

1t), contact 5, segment 15, wire 13 to the lingerie I main. will cause the magnet 1'02 tolbe energized, and'the latch will be Iribvedout of the path of the part' 25 by means of the connection between said electroniagnet and latch. The carrier. is now has to descend by reason ofits own weight.

'- We'will'now describe our automatic means for slowing'down the movement; of the carrier'and stopping same. at its lower limit of travel; At t 15 made connection'with the contact 5 it was brought jintoelectrical connection with the contact 6., thus short-cirouiting the motor-armature tluough'tl'lesame resistances used to accelerate the motor in starting the carrier in its upward movement and also additional re sistances 37, 38, and 39. On further movement of the handle;17 to the right thesegment will engage the fixed contacts 7 and 8. Contact 7 is connected to brush-7 6 on the automatic stop-motion switch. Contact 8 is .connectedby brush 90 with COIliifiCli-Slilll') 91 and brush 86 tothe electromagnet 66.0f the brake. -fhds thebrake-magnet will be at once energized, and the brake released, allowmg the motor lt'o be revolved backward by the load. Since themotor has its field 61 connected across the line by wires 11 and 12, the "same will be fully excited, and the arma-.

turebeingdriven by the load will generate a carrier descends the automatic stop-motion switch 75 will be: driven in a counter-clock- .wise direction by'the' hoisting machinery. As the car approachesjthe lower limit of its I travel the slowdown operation is automatic- =40- A switch. The first change will be the c0nnec ally controlled by means of said stop-motion tion of the fast speed magnet in shunt to the resistances 37,38, and 39. This shuntcircuit ma be traced from the w ire-29 to and through the magnet 45, brush 88, strip 94, brushes 51 and 76, contact 7, segment 15 to the other side of the load-magnet resistances. The load-magnet resistances combined are preferably greater than the combined accelerating'resistances, so that the energization of the magnet 45 depends on the potential across the load-magnet resistances. This potential varies directly as the speed of the car. If the speed be too great, this potential rises to such a point that magnet 45 is energized and short-circuits the resistance 32 .by closing-the contacts 46. The resistance in the armature-circuit being thus decreased, more current can flow, and the electrod namio braking action will be increased. car will therefore run at a reduced speed. The automatic stop-motion switch has now revolved, to such a' position that the-contactbrush 76 runs onto the contact-strip 78, ,to"hold said new at the upper. limit :of its which is connected to one terminal of thel e same time that the segment l ad-magnetAO by the contact-brush 77 and the circuit represented bybroken lines. The":

other terminal ofthe load-magnet is connected to the armature-brush 63. It will be seen that the load-magnet is now connected across or in shunt, to the motor-armature, and it the speed of the motor, to close more or less of its contacts 42, 43, and 44, which operate to cut out o'rshort-circuit the load resistance in a well-known Way and acting to further slow down the motor in proportion to the load.

'will be energized to a degree depending upon I The next operation of the automatic stopmotion switch is when the insulating-piece 92 engages the contact-brush 90. This will interrupt all current-supply to the brake-magnet 66,. and the the car at the bottom of its travel.

In reviewing the operation of the system brake will, be applied to stop it will be seen that when it is desired to raise a load the brake is first raised and current admitted to the motorthrough the starting resistance. Then a portion of the. starting resistance is short-circuited, which causes a. 0 somewhat higher speed. Then-magnets are e energized .to automatically short-circuit the remaining resistance in proportion. tothe load. I Asthe top of the'run is reachedfthe current to, the motor is automatically reducedtosuch an amount as will be necessary to bring the load gen'tl againstthebuffer at, f

the, brake being j heldoff, At the same time a lockjlngfdevice I00 movement, after which the brake maybe l the top'and hold it,,t ere,

effectually prevents any possible ownward applied by bringing the segment 15 back to central position.

To lower the can the brake.

is first lifted and the locking device, released. I

The motor isthen turnedbackward by the load and becomes a dynamo, generating current through thc'st arting resistance and load resistance which are together in series with the motor-armature. I Toward the lower end;

of travel a portion of the. starting resistance may be shoqt-circuited, depending on the speed of the car, and shortly afterward a.

magnet is shunted "across the armature, which operates to cutout the load resistance in proportion to the speed and load of. the descending car, and finally the brake is applied to stop the car.

. Without limiting ourselves to the precise construction or details and arrangement of parts as herein shown, but reserving the right to make such changes therein as' iallwithin the spirit andscope of our invention,

What we claim, and desire to be protected by Letters Patent, is+ Y 1. The combination a car,'of hoisting means therefor,-'an electric motor for operatmg said. hoistrng means, means for causing the motor acting through said hoistingmeans from falling, and means for electrically actuating said safety device so that the car may descend when desired.

2. The combination with a car, of means for hoisting said car, a stationary device for preventing said car from descending, and electric means for releasing said device so that th" car may descnd when desired.

3. The combination with a car, of means for hoisting said car, a self-locking device permitting free movement of the car in an upward direction but preventing the car from'descending, and electric means for unlocking said locking device so that the car may descend.

4. The combination with a car, of means for hoisting said car, a catch normally in the ath of a part of the car, and electromechanreal means for actuating said catch, so con-' structed and arranged that the car may have a free upward movementgbut is stopped in its downward movement unless .or until the catch is actuated.

5. The combination with a car, of operating means for the same, a catch for preventing movement of the car in one direction but permitting free movement in the other direction, an el'ectroresponsive device, and connections between said electroresponsive de vice and said catch whereby the catch can be so moved as to allow the car to move" freely past the same in either direction when the electroresponsive device is energized.

6. The combinationwith a car, of hoisting means for the same, a catch for preventing descent of-the car but allowing free upward movement thereof, electromechanical means for operating said catch, and an electric switch on the carrier closing a circuit to said electro'uiechanical means to actuate said catch so that the car may descend.

7. The con'ibination with a car, of hoisting means for the same, a self-locking device for allowing free upward movement of said car but preventing its downward movement, an electrores mnsivc device for operating said self-locking device, and an electric-switch on the car for controlling the circuit to said elent-nn'csponsive device, whereby when the latter is energized said self-locking device is actuated so.th'at thc cm' may move down ward l v.

h. The co'mbilation with a car, of lllilhilllfl means for the same, a hoiding device having a part cxtcnding into the path of travcl ol' the car for preventing ihc car from descending al'tcr lmving reached its upper limit of travel. and electric means for actuating said holding device so that the car may dcsccnd.

i). The combination with a car, of hoisting menus for the same, a self-locking dcvi'cc near the upper hunt of'travcl of said car forprcvcuting the same from descending, and an clcctrorcsponslvc device controlled l'rom lhc ran for operating said sell-locking device.

10. The combination with a car, of hoist= ing means for the same comprising an electric motor and main lines, a self-locking device near the upper limit of travel of said car for preventing the same from descending, an

electric switch in the car, and an electromagnet arranged to be placed across said mains and to actuate said self-locking device when energized so that the car may descend.

11. The combination with a car, of hoist- .ing means for the same, means for automatically reducmg the speed of said car as the same approaches the upper limit ofitstravel,

a self-locking device near said limit of travel,"

and-electric means controlled from the car for operating said self-locking device, the aforesaid parts being so constructed and arranged that the car may be heldelectrically by said hoisting means at said upper limit safety device near the said upper limit of' travel for preventing the car from falling, an electroresponsive device for actuating said safety device so that the car may descend \vhendesired, an electric switch for controlling the automatic slow-down means and for controlling said electroresponsive device the aforesaid parts being so constructed and acranged that when the carreaches the top it shall be held the e by said electric motor acting through the said hoisting means.

13. The combination with a car, of hoisting means for the same, means comprising a stop-motion switch arranged to be automatically rotated, for reducing the speed of said car as it approaches the upper limit of its travel and for holding the car at. said limit, a safety device near the upper limit of travel of said car for catching the -:u' if it should fall, an clcctrorcsponsive device for operating said safety device, and manually-operable switching mechanism for controlling the current to said automaticall v-rotatable switch and to said electroresponsive device.

ll. 'lhe combinal ion with a car, ol means for hoisling said car, an clectrhr, motor for driving said hoisting means, switching mechanism arranged lo be automatically rotated to control the circuits to said motor as the 'n r approaches its upper limit so that the lat- {or shall he reduced inspcml but sufficient currcnl allowed to llow through the motor to enable the same to cause the car to be held at its upper limit ol" travel, a self-locking device IlC near the said upper limit so constructed and.

as it approaches its upper limit of travel, the

.fore stop mg as said car approaches its lower car may move downwardly when desired, and circuits and connections, for gradually reduce a manually-operable switching device aring the speed of the car as it approadhesits ranged to close circuits to said automatic upper limit and cause the motortd hold said switching mechanism when in one position I car at that limit and for automatically IGClllG-S 5 and to close the circuit to said electromagnet when in another position. 15. The combination with a car, of means for hoisting same, an electric motor for driving said hoisting means, means comprising circuits and connections for automatically and gradually reducing the speed of the car said circuits and connections being so constructed and arranged that the car shall be held at its upper limit by said motor acting through said hoisting means, means for auto matically reducing the speed of the car belimit an varying such re notion of speed in accordance with the load, and a manuallyoperable switch for controlling when in one position-current to said automatic means for reducing the speed of the car as it approaches its upper limit and for controlling when in anot er position current to the lower-limit automatic means for slowing down the speed ofthe car. l

' 16. The combination with a car, of means for hoisting same, an electric motor for driving said hoisting means; means, comprising ing the speed of the car as it approaches its rying such reduction of speed in accordance with the load, means for stopping the car at its lower limit of travel, a safety device near the upper limit for'catching or holding the car should the hoisting means become inoperative, an electroresponsive device for actuating said safety device so that the car may controlling when in one position the upperlimit slow-down means and when in another position closing the circuit to said elcctroresponsive device and controlling the lower' limit slow-down means.

In testimony whereof we have signed our names to this specification in the presence of the subscribing witnesses. j

JOHN DIIH'LDER. nuMsnY w. sco'r'r;

Witnesses for Ihlder CHARLES M. N ssan,

C. BLINN- Witnesses for Scott:

J, E. WILSON, V

an automatically-rotatable limit-switch and GEORGE -J, Jonnsron.

lower limit by reason of its own load and ya descend, and a manually-operable switch for-

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