US1311262A - Elevatob - Google Patents

Description

E. PJCOLLINS ELEVATOR.

APPLICATION HLED mm. 19. 917. 1,31 1,262.

Pzitented July 29, 1919.

2 SHEETS-SHEET 1 we; I @QKZPQZ I E. P. COLLINS.

ELEVATOR APPLICATION FIL ED MAR. I9. I917.

Patented July 29, 1919.

2 SHEETS-SHERZ.

P. COLLINS, OF CHICAGO, ILLINOIS.

ELEVATOR Specification of Letters Patent.

Patented July 29, 1919.

Application filed larch 18, 1917. Serial No. 155,846.

To all whom it may concern:

Be it known that I, EDWARD P. COLLINS, a citizen of the United States, residing at Chi o, in the county of Cook and btate of Illinois, have invented certain new and useful Improvements in Elevators, of which the following is a specification.

This invention relates to elevators, and more particularly to electric elevators which are used as cranes for hoisting various material and machinery. It has for its object materially simplifying the controlling apparatus of the crane and at the same time retaining the ordinary functions of crane controllingasystems, and also adding new functions. I also add certain new andimproved safety devices to the system; all of which are fully shown and described by the following drawings and description:

Figure 1 of the drawing shows more or less diagrammatically an electric crane controlling system, together with certain safety devices which embody the features of my invention. Fig. 2 is a section along the. line 2-2 of Fig. 1. Fig. 3 is a detail view of a portion of the system. Fig. 4 is an enlarged detail view of one of the safety 'devices and the mechanism by which it is o erated. And Fig. 5 shows diagrannnatical y the elevating, the braking and the lowering electric circuits of the apparatus.

In elevating the carrier of an elevator or a crane it is desirable to have a series wound motor; but in lowering the carrier a shunt wound motor. is preferable, particularly if dynamic braking means are used. While it is old to have a motor controller for changing a motor from series to shunt connection, and the reverse; yet a portion of my invention consists in mechanism for accomplishing this in a simple manner, particularly in view of the other functionsof the system which has apparatus coacting with the motor controller.

I use in this instancea cylindrical form of motor controller 1, the cylinder being adapted to be rotated a limited distance in either direction from the neutral position, and having fingers 2 fixed to the frame of the controller and extending over the cylinder so as to come in contact with the con tact plates 3, 4, 5, and 6, fixed to the surface of the cylinder; and thus to produce the desired changes in wire connections, vario'us wires of the electric circuits being permanently connected with the fingers.

all of the plates 3 are connected, also all of plates 4, and all of plates 5; while plates 6 are connected in pairs.

The supply nrains 15 and 16 of the system are connected to the main switch 17. From this switch, wire 18 is connected with finger 19 through a switch 45, hereinafter described; while wire 20 is connected with finger 21 through a switch 22 and wire 23. Wire 20 is also connected with finger 25 through coils 41 and 40 and wire 27.

' In starting the motor, a switch 67 is closed and this closes a relay circuit through coil 68, wire 69, overload switch 7 5, wire 79, overload switch 26, wire 90, and wire 20 to the main switch. This circuit energizes coil 68 which closes switch 45. Then, as the controller plates 3 are turned toward the fingers 2, plate 28 comes in contact with finger 19 and a circuit is formed from the wire 16, through wire 18, switch 45, coil 91, plate 28, plate 29, finger 30, resistances 98', to'finger 31, wire 32, brake coil 33, field coil 34, the low resistance coils 35 and 36 hereinafter described, armature coils 37, wire 38, finger 94, plates 5, finger 21, wire 23, and, as soon as the switch 22 is closed, the circuit will be complete, forming a series connected motor system. But at the same time the armature is shorted'by the following circuit: from coil 35 to plate 56, brush 57,

plate 58, wire 59, plate 60, brush 61, plate 62, wire 63, finger 64, plate 76, wire 9,

plate '7 8, and finger 21.

The switch 22 is adapted to eleminate the heavy sparking current from the controller contacts. This switch remains open until plate 39 comes in contact with finger 25. Current then flows from the supply wire 16, through finger 19, plates 28 and 39, finger 25,.wire 27, resistance coil 40, electromagnet coil 41, and wire20 to the supply wire 15. This causes the electromagnet 42 to close the switch 22, and thus to close both of the above described circuits. f

In case of an overload, at any time, coil 43 opens the switch 26, or coil 91, opens the switch 75, breaking the circuit through coil 68, and releasing switch 45 which is forced open by the spring 99. Switch 67 is normally forced open by the spring 111, the

current through coil 68 and the lamp 112 being sufiicient to hold switch closed after it has been closed by manually closing switch 67 and shorting the lamp.

Coil 36 is also shorted by the above specified circuit through wires 59, and 63. Hence this coil 36 receives substantially no current; but coil 35 is fully energized, and core 80 is pulled thereby inwardly and brush 61 passes 'from 'plate 60 to plate 84, thus opening the circuit through wire 63 which shorted'coil 36 and the armature. Then coil 36 becomes fully energized and core 81 is pulled inwardly and brush 57 changes from plate 58 to plate 85. The shifting of the brushes 6-1 and 57 in the above described, manner connects the safety switch 70 with the source of electric supply for purposes hereinafter described.

By shorting coil 36 and the armature coils, as stated, the brake coil 33.receives sufficient current to fully overcome the inertia and any sticking of the parts, and to thus fully release the brake. After the shorting circuit is opened by the energized coil 35 shifting brush 6]., the brake coil receives less current but sufficient to keep the brake caed by Fig. 3. This disconnects the supply lines, and coils 35 and 36 being denerglzed, the respective springs 92 and 93 force the brushes 61' and 57 to plates 60 and 58. The carrier is then lowered by reversing the motor and at the same time connecting it as a shunt motor. This is accomplished by bringing plates 4 into operation. As plate 46 touches finger 19 a circuit is formed through wire 8, plate 47, finger 48, resistance coil 49, finger 31, wire 32, to the brake and the field coils 33 and 34, and to coil 35. Also from finger 48 through the remainder of the resistances 98, finger 30, wire 50, the

adjustable resistances 51, finger 52, wire 12,

" plate 53, Wire 10, plate 54, wire 13-, finger 94, wire 38, armature coils 37, to coil 36. Hence the field and armature coils are in parallel. From coils 35 and 36, where the field and armature circuits join, the current is free to flow through wire 55, plate 56, brush 57, plate 58, wire 59, plate 60, brush 61, plate 62, wire 63, finger 64, plate 65,

. wire 11, plate 66, finger 21, wire 23, and,

when the switch 22 is closed, through the the mechanical brake and also of the dyotherwise, and thus stops the motor.

switch, wire 20 and switch 17 to the supply. Switch 22 is closed as before as soon as plate 67 touchesfinger 25. See the lowering circuit; Fig. 5; As the controller cylinder is rotated further the resistances 98 are gradually cut out of the armature circuit and into the field circuit by the plates 4 coming successively in contact with the fingers 2.

If, now, it is desired to-stop the motor with the carrier and its load suspended, the controller is thrown back into neutral posi- .tion, thus cutting off the supply current. Simultaneously wlth the cuttmg oil of the supply current, a dynamic-brake circuit is closed through the armature and the controller, as follows; from the armature coils 37, through wire 3'8, to finger 94, plates 54 and 53, finger 52, coil 51, finger 30, resistances 98, finger 31, wires-14 and 24, field coil 34, coils 35 and 36 to the armature;

thus shorting the electrically operated mechanical brake coil and thus applying the mechanical brake and allowing the load to come to rest under the retarding action of namic brake formed by. the closed circuit through the armature. See the braking circuit; Fig. 5. It is. customary with elevators, cranes and other hoisting mechanism to have limit switches, and especially switches limiting the height to which the carrier can be raised. switches for this purpose may be normally closed or open. I prefer for the purposes of illustrating my invention to use a normally op'en switch, which, when the height limit is reached, is closed by the carrier pr 11 this instance I arrange the system so that when the switch is closed the motor armature coils are shorted and hence the motor is brought to rest. It has beenfound that, with up limit switches, mounted as they are usually adjacent the elevating cables, and with the electric Wires thus'likely to come in contact with the cables, the insulation of the wires sometimes becomes worn, and sparking acrossto the cables results, with serious injury thereto. To reduce this hazard to a-minimum I provide improved apparatus.

The up limit-switch is useful of course only as the load ascends; hence I arrange to have no electromotive force effective in the switch wires except as the load is ascending. As the cables are then always taut the danger of contact with the' switch wires is slight.

To provide for descending, and toeliminate the electric force from the wires while descending, and also in order to eliminate the trolley wire from the motor system to the controller system, I provide the-sole noid coils 35 and 36 above referred to. hen the controller is operated to raise the 186 load, as hereinabove explained, current first flows through coil 35, shifting brush 61, to plate 84-, and then sufiicient current flows through coil 36 to shift brush 52 to plate 85, thus connecting to the armature blade 86 of the up limit switch through coil 36, wire 55, plate 56, brush 57, plate 85, and wire 87; and at the same time connecting blade 88 to the other side of the annature by nieans of wire 89,:plate 84, brush 61, plate 62, wire 63, finger 64, plates 76 and 77, finger 94, and wire 38. Hence when switch 70 is closed the armature coils will be shorted, and thus at all times, as the load rises, a circuit is formed adapted to short the armature when ever the up limit switch is closed. The switch 70 is suspended in any suitable man ner adjacent the vertical path of the carrier 71, and comprises any suitable switch that ma y be closed by a finger 72 projecting from the carrier. A

When the controller is thrown to neutral position the coils 35 and 36 are denergized, and springs 92 and 93 pull the respective arms 61 and 57 back to normal positions.

and the electromotive force is excluded from both blades of the switch; and when the descending side of the controller is thrown into action, as hereinabove explained, current passes through coils 35 and 36 in parallel, the direction of the flow in coil 36 being reversed. As a consequence the magnetic fields of the coils oppose each other andthe cores 80 and 81 are held apart keeping the brushes 61 and 57 on the respective plates 60 and 58; and the electric force is thus excluded from both blades of the up limit switch at all times except when the load is ascending.

The resistance 51 may be adjusted to meet the needs of the various conditions that may exist, giving to the armaturethe desired speed and amount of current. The resistance 49 prevents too great a flow of. current through the .field and brake coils when they are .in parallel with the armature, and this resistance is not cut out by rotating the controller cylinder to the full on position; on the contrary the remaining resistances 98 are gradually cut into the field circuit, weakening the field so as to increase the speed of the armature. And it will be seen that, as arranged, each of the short plates 4 varies the relative resistances through the armature and the field coils not only as it touches its corresponding finger but also as it leaves the. finger; thus making the resistance variation more gradual.

As an additional safety means I provide an up limit switch 100 which is operated by a screw 101 operatively connected to the drum shaft 102, or operated in any other suitable manner. In case the switch 70 for any reason is not efiective, the switch 100 will bring the motor to rest in the 'following manner: As hereinabove explained,

while the load is being raised, coils 35 and 36 are receiving current in series, and maintain brushes 61 and 57 on the respective contacts 84 and 85. If, however, the coils 35 and 36 are shorted the current through the coils will be so slight that the springs 92 and 93 will pull the respective brushes back onto contacts 60 and 58, and the armature will then be shorted by the circuit 59 and 63 as hereinabove explained, and the motor will stop. Now wires 96 and 97 pass from the outer terminals of the respective coils 35 and 36 to the blades 103 and 104 which are arranged to be shorted by a plate 105. This plate is mounted on pivoted levers 106 which are arranged, respectively, to be operated by the pivoted levers 107. These levers are all pivoted to a non-rotatable block 108 into which is threaded the screw shaft 101; while trips 109 are arranged to operate the levers 107 at the proper time. As the load rises the block 108 is forced to the right by the screw rod, and the levers 107, and thus also the levers 106, are operated by the trips 109 against the centering springs 110, turning the plate 105 away from the blades 103 and 104 until the trip is passed, when the plate will quickly short the blades and thus the coils 35 and 36; similarly as the load descends the trip will cause a quick separation of the plates 105 and the blades; thus preventing undesirable sparking.

Attention is called to the fact that, although both of the limit switches 70 and 100 may be closed, this in no way interferes with lowering the load, as the reversing of the motor is taken care of by plates 4 and 6, and the circuits formed by these plates are in no way affected by the shorts caused by switches 70 and 100, as wire 63, as above explained, forms the return wire for both the armature and the field coils. The safety switches may be arranged so that either one will operate before the other, or so that they will operate simultaneously.

I claim as my invention:

1. In a crane system a brake having an electromagnetic coil, a motor having field and armature coils, means for connecting all of said coils in series and at the same time for shorting the armature coilby a circuit, and means, operated by the electric current flowing through said brake coil, for opening said shorting circuit.

2. In a hoisting system, brake coils and motor coils, means for connecting said coils in series by one circuit, means for shorting said motor coils by another circuit, means for then openin said shorting circuit by the current passing through said brake coil, and additional means for opening said shorting circuit by the current which passes through the motor coils when the first opening means operate.

. in one position said coils being connected in series but with said switch open, when sald member is in another posltionsaid connectlons being unchanged but said switch being closed, when sa1d member is in a third position said coils being connected in parallel with said switch open, and when said member is in a fourth position said con} nections being unchanged from that of said third position but said switch being closed.

4. In a hoisting system a motor, means for connecting alternately said motor as a shunt or as a series motor in circuits having a common switch, and means operated automatically by said former means for closing said switch after either of said connections has been made.

5. In an elevating system an electrically operated brake having coils, an electric motor comprisin armature and field coils in series, means or connecting the coils of said brake and said armature in series in one circuit and for simultaneously shorting said armature coils by another circuit.

6. In an electric hoisting system an up limit switch and automatic means for disconnecting said switch entirely from the source of electric power at all times except when said system is in elevating operation.

7. In an electric hoisting system an up limit switch and means for disconnecting said switch entirely from the source of electric power at all times except when said system is in elevating operation, said means comprising a pair of adjacent soleno1d coils, the currents through said coils when said load is being lowered coacting to produce two opposing fields.

8. In a hoisting system, a motor, an up limit switch, means for connecting said motor as a shunt wound and also as a series wound motor, and means for disconnecting said switch from the source of electric power when said motor is shunt connected.

9. In a hoisting system, a motor, an up limit switch, meansfor connecting said motor as a shunt wound and also as a series wound motor, and means for disconnecting said swltch from the source of electric power when said motor is shunt connected, said means comprising two adjacent solenoid coils, when said motor is series connected the said coils being connected in series but when said motor is shunt connected said coils being connected in parallel.

10. In a hoisting mechanism a motor having a field and an armature coil, two solenoid coils, and a limit switch arranged 'to be connected to the source of electric supply by said solenoid coils, and means for connecting all of said coils in series and means for connecting each of said field and, said armature coils in series with one of said solenoid coils and for connecting said two latter pairs of series coils in parallel with each other.

1-1. In an electric hoisting system an up limit switch and means for disconnecting said switch entirely from the source of electric power at all times except when said system is in elevating operation, said meanscomprising a pair of adjacent solenoid coils, the currents through said coils when said load is being lowered coacting to produce two opposing fields, and means for shorting said solenoid coils.

12. In a, hoisting'system a limit switch, resilient means tending to disconnect said switch from the source of electric supply, an electric c011 tending when energized to tive only when said system is elevating forclosing sai'd operating switches, and other means operated by said system for closing said limit switch.

' 14. In an electric h'oist, an electric motor, an operating circuit, an independent circuit across thete'rminals of said motor, a limit switch in said independent circuit, an operating switch in said independent circuit each side of said limit switch, resilient means tending to open said operating switches, electric means connected in said operating circuit arranged to close said operating switches when said motor is elevating a load, means for closing said limit switch, and other means for shorting said electric means when said motor is elevating.

15. In a crane system a brake having an electromagnetic coil, a motor having field and armature coils, means for connecting all of said coils in series and at the same time for shorting the armature coil by a circuit, and means, independent of said brake mechanism but operated by the electric current flowing through said brake coil, for opening said shorting circuit.

In testimony whereof, I hereunto set my

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