US981919A - Safety device for alternating-current hoisting apparatus. - Google Patents

Description

W. N. DICKINSON, J11.

SAFETY DEVICE FOR ALTERNATING CURRENT HOISTING APPARATUS. APPLICATION FILED JUNE 14,1906.

981,919. Patented Jan.17,1911.

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W. N. DICKINSON, J11.

SAFETY 1mm FOB. ALTBRNATING GURRENT amma APPARATUS.

APPLICATION TILED JUNE 14, 1906. 981,919 Patented Jan.17,1911.

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UNITED STATES PATENT OFFICE.

WILLIAM N. DICKINSON, JR., OF NEW YORK, N. Y., ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SAFETY DEVICE FOR ALTERNATING-OURRENT HOISTING APPARATUS.

Specification of Letters Patent.

Patented Jan. 1'7, 1911.

To all whom it may concern:

Be it known that I, WILLIAM N. DICKIN- SON, Jr., a citizen of the United States, residing at New York city, borough of Brooklyn, and State of New York, have invented a new and useful Improvement in Safety Devices for Alternating-Current Hoisting Apparatus, of which the following is a specification.

My invention relates to protective apparatus for electric motors and although it is herein shown applied to a motor connected to an elevator, it may have a general application.

One of the objects of my invention is the provision of means to effect the stopping of a motor upon the interruption of current supply.

A further object of the present inventionis to provide means for retarding or stopping an alternating current electric motor upon reversal of phase relation of the current supply.

Another object of my invention is the provision of a safety device to effect the stopping of the motor of an alternating current elevator system in the event of interruption of current supply or reversal of phase relation of the latter.

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

In the accompanying drawings, Figure 1 represents more or less diagrammatically my invention applied to an alternating current electric elevator system; Fig. 2 is a detail view of means for actuating a switch from the hoisting drum; and Fig. 3 is a diagrammatic illustration of a modified form of my invention.

A multiphase alternating current direct connected elevator equipped with a mechanical brake in simple form, has in it several danger elements which may be due to any one or more of the following sources :(a) running away of the car from rest due to the releasing of the brake without the application of current to the motor to operate the latter; (1)) running away of the car due to the interruption of the current supply while the elevator is in operation; (0) running of the car through its automatics in the wrong direction due to the reversal of phase rela- To provide against these contingencies I place an electro-Inagnet in the connecting link between the brake-releasing lever and the means of transmitting the control movement from the car. This electro-magnet is energized under certain conditions from the same line circuit as that from which the motor receives its current supply. The apparatus is so arranged that in the event of the control being operated to start the elevator, the brake would be lifted by an expenditure of current equal only to that required by the magnet as a holding magnet, that is, as an alternating current magnet with its magnetic circuit closed at the time the current is supplied to its energizing coils, provided current is available. If current is not available for energizing the brake magnet, the mechanical control movement could take place but the brake would not be released. Considering also the liability of a simple machine running away on the interruption of current during the operation of the elevator, such interruption would immediately effect the deenergization of the brake magnet. The latter would therefore fall and apply the brake at practically the same time that the current supply to the motor is interrupted.

To provide against the possible reversal in phase relation on the exterior circuit, an extra contact on each side of the main controlling 'switch is provided, said contact be ing placed in series with a corresponding contact in proximity to the high speed or low speed shaft of the elevator hoisting drum. In connection with such shaft I provide a movable contact arm so arranged that it will 0 erate against one or the other of the two xed contacts in its path, depending upon the direction of rotation of the shaft.

The circuits are arranged in such manner that if on the movement of the car control in a given direction, the elevator machine moves in a direction corresponding to that for which the control has been adjusted and the automatics set, no circuit will be completed to a tripping coil of the main line switch. If, however, the winding machine does not move in the direction for which the automatics are set, and the direction the movementof the car hand rope or lever calls for, the shaft actuated contact moving in a direction opposite to that from normal when considered with relation to the direction in which the control switch has been thrown,-

will complete an electric circuit through the tripping coil of the main line switch and thus effect the opening of the latter. By so doing the .-.urrent supply is cut oil from the motor and also at the same time from the brake magnet. The elevator is thus brought to rest and maintained in such position until an attendant has visited the winding machine and has supposedly properly readjusted the elevator before again throwing in the main line switch in regular operation.

Referring now to the drawing before a detailed explanation of an application of my invention, it will be seen that a motor M mounted on the bed plate B is connected to the hoisting apparatus E to which in turn is connected the car C by means of the cable 78 which passes over the sheaves 79 and 80.

H designates a hand rope which passes through the car and is connected tothe sheave 1 loosely mounted on the hoisting drum shaft 43. F ixed to the pulley 1 is a pinion 20 which is in mesh with the rack 21 at one end of the bar 16, the other end of which is provided with a rack 22 in mesh with the segment gear 23 of the main controlling switch 26.

2 designates an arm or contact carrying a weight 4 at its lower end so as to be normally held in vertical position as shown in Fig. 2 midway between the fixed contacts 6 and (3. When the motor is starting and the arm 2 moved against one of the fixed contacts 6 or 6, a circuit should not be established, for if desired, the tripping coil of the main line switch will be operated to effect the opening of the latter. Movement of the arm 2 when the drum shaft 43 is r0- tated may be established by friction, ratchet, magnetic, or other influences as may be desired. In this instance a small electro-magnet 41 in attracting its armature 42 clamps the contact arm 2 to the hoisting drum shaft 43 and thus produces suflicient friction between the contact arm and shaft to cause the former to move against one of the fixed contacts 6 or 6, depending upon the direction of movement of the hoisting drum.

On the motor shaft 5 is mounted the brake pulley or coupling 8 with which is associated the brake 7. This brake may be operated in any manner desired, but in this instance I have shown toggle mechanism and a brake lever 10 connected to the vertical rod 19 which is movable in the fixed guide (30. At. the upper end of the rod 19 is connected an electro-magnet 14. The armature 18 of this brake electro-magnet normally closes the magnetic circuit of the latter and is connected by means of the rod 12 passing through the fixed guide 11 to the anti-friction roller 13. This roller normally lies in a recess 61 in the bar 16, but when the latter is moved in its guides 17, 17, the cam 15 or 15 will engage said roller 13 to effect the lifting of the rod 12 and the parts connected therewith. If at this time the magnet 14 is energized, the brake will be released and the motor may start if it receives current from the main line.

It will be noticed that when the hand rope H is actuated from the car, and the pulley 1 rotated, the actuating bar 16 will be moved longitudinally to effect the closure of the control switch 26 so as to close the motor circuits in one direction or the other. In addition to the motor circuits, the switch 26 also controls the circuit to the electromagnet 14. Assuming that the hand rope H is moved downwardly, the actuating bar 16 will be moved to the right as viewed in Fig. 1 and the switch arm 25 will be moved to the left. This switch arm carries a plurality of insulated contacts connected to gether and so arranged as to secure the desired operation of the motor when cooperating with the segmental fixed contacts shown. It should be noted that the upper three segmental contacts are engaged first or before the lower three contacts. This has the effect of closing the circuit to the electro-magnet 14 from the main lines a, b, 0, through the main line switch L, leads a, b, c, and thence through the switch 26 to the conductors 62 in the following manner: The lead a will be connected to the contact 36 and thence to the fixed segment 32 and by way of wire 63 to the magnet 14. The lead I) is connected directly to the magnet 14 at the point 64. The lead 0 is connected to the contact 30 and thence by way of wire 29 to segment 31 and wire 65, to the electromagnet 14.

It should be noted that upon the engagement of the upper three contacts of the switch arm 25 with the corresponding segments 28, 31 and 32, the electro-niagnet 14 -is energized but it will consume little currentby reason of its magnetic circuit being closed by the armature 18. Furthern'iore at this time the circuit to the motor and the circuit to the friction magnet 41 are still open. Upon further movement of the rod 16, however, the segments 33, 34 and 35 are engaged by the corresponding contacts 36, 37 and 38 on the switch arni 25, and the circuit 34 to the motor thus closed. The magnet 41 being connected in shunt to the motor, will be energized at the same time. At about the time that the rotor circuit is closed, the cam 15 engages the roller 13 to effect the lifting of the brake. The motor may now start to move the car in the desired direction, in this instance upwardly. The hoisting drum being moved in an anti-clockwise direction as viewed in Fig. 1, and the magnet 41 having been energized, the contact 2 will be moved against the contact (3',

but the latter being connected by means of the wire 27, to the open segment 28, the circuit through the tripping eoil l? of the main line switch L will not be closed.

It should be noted that reference to the shaft of the winding machine for the purpose of communicating motion to the movable contact arm 2 is made herein merely as a com-*enience, as it will be evident that any part of the mechanism which changes its direction, on change of direction of movement of the car, may be utilized for imparting the proper motion to this contact arm.

The main line switch L is illustrated diagramn'iatically and so also its releasing device. This mechanism may be varied as desired in its details without departing from the principle of my invention. On the lever 48 are mounted the movable insulated contacts, this lever being pivoted at 50 and provided with a handle 49. Cooperating with its outer end is a latch 51 pivoted at 52 and provided with an arm 53 extending over the tripping electro-magnet 47. The latter is provided with a movable core so that when energized, said core will be projected upwardly against the arm 53 and move the latch 51 out of engagement with the lever 48. pended upon to open the switch or a spring may be used for such purpose.

By the use of the arrangement herein shown, it will be evident that whenever the brake is released, current will be supplied to the motor, and that if no current is on the line the brake magnet 14: would not be energized and therefore the brake could not be released. The car could therefore not run away from rest by any releasing of the brake without current being supplied to the motor. It will also be obvious that if the current supply should be cut ofi while the car is running, the brake magnet 1st would immediately fall and its weight or an additional spring would immediately apply the brake to stop the motor-hoisting apparatus and car. Should a reversal of phase relation on the line take place and the hand rope H is operated as before, that is downwardly, to eifect an upward movement of the car, current will be supplied to the motor to operate it in the opposite direction and therefore tend to move the car downwardly. If this occurred and the car continued in its downward travel, its engagement with the automatic lower limit stop button 66 would have no efl'ect in operating the control apparatus to stop the car as this button would already be in its lowest position. But when the motor is thus operated in the wrong direction, it should be noted that the contact arm 2 will be moved against the fixed contact 6 instead of the contact (3. In such event a circuit will be closed from the lead Z) through the tripping electro- The weight of the lever may be demagnet 47, wire 9, contact arm 2, contact (3, wire 27, contact segment 28, outermost contact on the switch arm 25, wire 2.), contact; 30, and wire a, to one of the other main lines, in this instance 6. The latch 51 will thereupon be released and the main line switch L allowed to drop to open position. The current will therefore be cut off from the electromagnet l4 and from the motor, and the brake will be applied to effect the stopping of the car before it could travel any more than a short distance. The weight t will also return the arm 2 to central position as the magnet 41 will also be deenergized. The switch 26 can then be returned to central position, and after the circuits have been properly re-arranged with respect to the main line, so that the motor will operate to move the car in the proper direction, the switch L may be manually closed to restore the system to operative conditions The brake apparatus may be varied as desired; for instance it may be released electrically instead of mechanically.

It should be understood that I have shown a gravity main line switch for the sake of simplicity and that a vertically pivoted spring actuated switch or other type of switch may be used instead if desired. In some cases it may be desirable to employ a potential magnet in place of the tripping elect-ro-n'iagnet shown in Fig. 1. Such a potential electro-magnet with the proper connections to effect the opening of the main line switch in the event of the potential falling below a predetermined value, is shown in Fig. 3. The interruption of the circuit including the potential magnet would effect the operation of the latch mechanism to open the main line switch. In Fig. 3 is also shownstarting apparatus comprising sectional resistance R, accelerating magnets 58, and switches 54:, 55, 56. The sectional resistance and switches are connected to the slip rings (57 of the rotor of the multiphase induction mtoor M. The accelerating magnets 58 are supplied with current by the circuit 57 tapped across two of the motor leads so that said accelerating magnets will receive single-phase current. \Vhen the motor starts, the switches 54:, 55 and 56 will be closed successively but not too quickly. To effect such operation various devices may be used, but in this instance I have shown dash-pots 59 so regulated that their retarding effect will produce a successive actuation on closing of said switches.

It should be noted that when the main line switch L has been closed as by means of the handle 4&9, the magnet 4-7 should be maintained energized so as to hold said switch closed. At the beginning of the operation of the motor, or when the switch 26 is first closed so as to supply current to the motor, a circuit extends through the magnet- 47 by way of wire 9, wire 44, switch 45, and wire 46 to the lead The connections between the fixed contacts 6, (3' and the segmental contacts 28, 28 are reversed in Fig.

5 3 so that when the contact arm 2 engages the contact- 6 or 6', a second circuit will be completed through the electro-magnet 47'. Upon the operation of the switch 26 so as to move the arm to its left-hand position, the car 10 will start upwardly and the contact arm 2 will engage the contact 6. The switch 45 may be connected to any one of the accelerating magnets but it should not be opened until after the contact arm 2 engages the contact 6 or 6, in this instance 6. Therefore, as soon as current is supplied to the motor and the accelerating apparatus operates, the switch 45 will become opened after the contact arm 2 engages the contact 6'. The magnet 47 will therefore be maintained energized by current flowing through the wire 9, contact arm 2, contact 6, wire 27, contact segment 28, wire 29, contact 30, to lead 0. In other words, I have arranged in Fig. 3 in conjunction with the two fixed contacts 28, 28' of the controlling switch 26, and the two fixed contacts 6, 6' adjacent to the elevator shaft, and the movable contact-arm 2 engaging with one of the other 30 stationary contacts 6 or 6', depending upon the direction of movement of the elevator mechanism, connections through the switch 45 co-acting with one of the short-circuiting or accelerating devices. The switch 45 may be operated by an independent device if desired provided it has a properly arranged time element, in such manner that the circuit through the potential magnet is intact while the elevator is at rest, and is also held intact when the elevator starts in the direction corresponding with that for which the automatics and controlling switch are set and connected.- In this instance the circuit for the potential magnet is completed through the switch 45 when the accelerating switch 55 is in open position; and through the movable contact-arm 2 on the elevator shaft 43 and its proper stationary contact 6 or G at the time that the accelerating switch closes in the course of its regular operation, and thus open switch 45. If, however, the direction of movement of the elevator mechanism does not correspond with the direction for which the machine automatics and controlling switch are set and connected, or in other words, if the phase relation of the current is reversed producing the above results, the movable contact arm 2 actuated by the elevator shaft 6 will move in the opposite direction to that necessary to complete the energizing circuit of the potential electro-magnet 47 at the time that the accelerating or other time element switch opens. The current through the potential magnet will therefore be interrupted and the main line switch will immediately open, interrupting the current supply to the motor, and to the magnet 14, thus allowing the brake to be applied to bring the elevator to rest and maintain it 71,} in such position until the elevator has been inspected, the circuits properly re-arranged, and the main line switch L again closed. This operation will be clear if it is assumed that the switch 26 is operated by a down- 5 ward movement of the hand rope H to place the switch arm 26 in its left-hand position. The car should now be moved upwardly, but by reason of reversal of phase relation,

it starts downwardly, and the contact arm 2 89 engages the contact 6. Before the motor has attained full speed, however, the switch 45 will be opened and the electro-magnet 47 consequently deenergized for the reason that the contact 6 is now connected to the 5 open contact segment 28 of the control switch 26.

The references herein made to danger elements and the safeguards to cover the same apply equally as well to ordinary 90 types of single-phase motors in so far as failure of current supply is concerned, but in a single-phase circuit the feature of reversal of phase relation is not present.

Obviously those skilled in the art may 5 make various changes in the details and arrangement of parts herein shown without departing from the spirit and scope of my invention as defined by the claims. I desire therefore not to be limited to the precise 10o construction herein disclosed.

Having thus fully described my invention, what I claim and desire to have protected by Letters Patent of the United States is 1. The combination with a motor, of a brake therefor, a multi-phase electro-ma-gnet connected to said brake, an armature normally closing the magnetic circuit of said magnet, and mechanical means independent of the motor for actuating said armature and electroqnagnet to effect a. release of the brake only when said magnet is energized.

2. The combination with a motor, of controlling means therefor, a safety device, and a switch operated by the motor and co-acting with the said controlling means to effect the operation of said safety device to stop the motor when the latter rotates in a contrary direction.

3. The combination with a motor, of a main line switch therefor, a tripping device for opening said switch, motor-controlling means, and a switch operated by the motor and coacting wit-h said motor-controlling means to effect the operation of the tripping device upon the motor starting in a direction contrary to that selected.

4. The combination with a motor, of a. source of multiphase current supply therefor, motor-controlling means, a main line switch, a tripping device therefor, an additional switch. operated by the motor and coacting with the motor-controlling means to effect the operation of the tripping device and the interruption of current to the motor upon the phase relation of the current on the main line being reversed.

5. The combination with a motor, of a brake therefor, a multi-phase electroanagnet connected to said brake, an armature normally closing the magnetic circuit of said elcctro-magnet, a switch for connecting a source of current supply to said electromagnet, and single mechanism for closing said switch to energize said electro-magnet and for lifting said armature and electromagnet to etlect the release of the brake.

(3. The combination with a motor, of a brake therefor, mechanical actuating mechanism, a multi-phase electro-magnet, and an armature normally closing the magnetic circuit of said electro-magnet, said electro-magnet and armature being connected between the brake and actuating mechanism.

7. The combination with a motor, of a brake, a shipper bar, operating appliances for said bar, a motor-controlling switch opcratively connected to said shipper bar, a multi-phase electro-magnet and an armature therefor normally closing its magnetic circuit, and connections between the said armature and electro-magnct and the brake and shipper bar.

8. The combination with a motor, of a member rotated by said motor, a friction clutch mounted on said member, a switch lever connected to said clutch, contacts in the path of movement of said lever, an elecfro-magnet for operating said clutch, and means controlled by said lever and contacts to effect the stopping of the motor if it rotates contrary to a selected direction.

9. The combination with a multiphase motor, of controlling means therefor, a main line switch, electro-magnetic tripping apparatus connected to said main line switch,

an auxiliary switch cooperating with said controlling means, and an additional switch operated by the motor and co-acting with said auxiliary switch to close a circuit to effect the operation of the tripping apparatus.

10. The combination with a multiphase motor, of brake apparatus therefor, an electric switch for controlling the direction of rotation of said motor, an additional switch co-acting with said controlling switch for effecting the operation of the brake apparatus to release the brake, a main line switch, a tripping device therefor, an auxiliary switch cooperating with the controlling switch, a safety switch operated in one direction or the other depending on the direction of rotation of the motor, and connections between the auxiliary switch, safety switch and tripping device to effect the operation of the latter to cut 0H current from the motor when the phase relation of the main line current is reversed and the motor starts in a direction opposite to that desired.

11. In an elevator system, the combination with a car, hoisting apparatus and a multiphase motor, of a switch for completing a circuit to the motor, a tripping device, a safety switch operated by a moving part and tending to close a circuit to operate said tripping device, motor-controlling apparatus, and an auxiliary switch cooperating with the motor-controlling apparatus and effecting the operation of said tripping device through said safety switch when the motor turns in the wrong direction due to reversal of phase relation of the current supplied to the motor.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

WILLIAM N. DICKINSON, Jn.

\Vitnesses:

W. H. Scronns, CHARLES M. NISSEN.

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