US981671A - Electromagnetic braking mechanism for elevator-cars. - Google Patents

Description

H. M. P. MURPHY. ELECTROMAGNETIC BRAKING mnemmsm r011 ELEVATOR CARS.

APPLICATION FILED JUNE 9, 1910.

981,671 Patented Ja1117,1911.

5 SHEEN-SHEET 1.

TTTT an'ms Plrnu cm, wnsnmsrmv, 01 c.

H. M. P. MURPHY. ELECTROMAGNETIC BRAKING MECHANISM FOR ELEVATOR CARS.

nr-mcuxox rum) 11111119, 1910.

981,671. Patented Jan. 17,1911.

' 5 SHEETS-SHEET 2.

H. M. P. MURPHY. ELECTROMAGNETIC BRAKING MECHANISM FOR ELEVATOR CARS.

APP LIGATION II LBD JUNEQ, 1910.

Patented Jan. 17, 1911.

5 SHEETS-SHEET 3.

)3 woe wi'o-z M. v 35 fiattozucqs I witflwoeo mum 1n: nomuk PETERS cm, wAsHmcmn, u. c.

H. M. P. MURPHY.

ELECTROMAGNETIC BRAKING MECHANISM FOR ELEVATOR (JARS.

APPLICATION FILED JUNE 9, 1910.

Patented J an. ,17, 1911.

5 SHEETS-SHEET 4.

woe/Mon win m2 was 7 H. M. P. MURPHY. ELECTROMAGNETIC BRAKING MECHANISM FOR ELEVATOR CARS.

I APPLICATION FILED JU-HI19, 1910. Jan 5 SHEETS-SHEET 5.

4a I If; i v i III I I I IIP l A .rin: nouns nrrtns ca, wAsumcroN, n.

"UNITED sTAa s PATENT OFFICE.

HOWARD M. 1?. MURPHY, OF SCARSDALE, NEW YORK, ASSIGNOR TO LE ROY CLARK, OF NEW YORK, N. Y.

ELECTROMAGNETIC BRAKING MECHANISM FOR ELEVATOR CARS.

T 0 all whom it may concern:

Be it known that I, HOWARD M. P. MUR- rnY, a citizen of the United States, residing at Scarsdale, in the county of \Vestchester and State of New York, have invented certain new and useful Improvements in Electromagnetic Braking Mechanism for Elevator-Cars, of which the following is a full, clear, and exact description.

My invention relates to braking mechanism for elevators, the object of the same being to provide an electromagnetic device of this kind which is adapted to be auto matically thrown into operation when the speed of the car in either direction exceeds a certain predetermined limit, or when the hoisting cable or plunger breaks, which is also adapted to be manually thrown into operation fromv a point inside the car, or outside thereof, and which may be partially released for the purpose of permitting the car to descend slowly and safely to one of the floors in order to permit the passengers to leave the car.

In carrying out the invention I provide, preferably upon opposite sides of the car, a pair of electro-magnets, which, with certain of the parts connected thereto and operated thereby, are flexibly supported from the car, so that independent movement between the car and said magnets is permitted. The core of each magnet is so shaped and disposed that it will cooperate with a fixed armature extending longitudinally of the elevator shaft, so that when the magnet is energized a retarding effect will be produced on the magnet which, through a system of levers, will be transmitted to gripping devices cooperating with the guide rails or other fixed parts with sufficient force to arrest or entirely stop the movement of the car in either direction.

The details of the invention will hereinafter appear, and the novel features thereof will be set forth in the claims.

In the drawings forming part of this specification: Figure 1 is an elevation of an elevator car showing my improvements applied thereto; Fig. 2 is a similar view taken at right angles to Fig. 1; Fig. 3 is a sectional elevation, on an enlarged scale, of one of the magnets and the leverage system between it and the brake-shoes; Fig. 4 is a similar view taken at right angles to Fig. 3; Fig. 5 is a view similar to Fig. 3, showing a modified Specification of Letters Patent.

Application filed June 9, 1910.

Patented Jan. 17, 1911.

Serial No. 566,099.

construction; Fig. 6 is a detail side elevation, partly in section, of one of the magnets and its core disconnected from the other parts; Fig. 7 is a section on the line 7-7 of Fig. 6, and Fig. 8 is a diagrammatic view of the circuit connect-ions.

Like reference numerals indicate like parts in the different Views.

The elevator car 1 is movable in the usual manner in the shaft 2 in which are located the iron or steel T-rails 3. These rails may be the ordinary guide rails for the car 1, or they may be separate and independent therefrom. Secured to each side of the car adjacent to the rails 3 is a bracket 4 upon which are fulcrumed the angle levers 5. These levers are pivoted at their upper ends to the gripping devices 6, shown in the form of the usual brake-shoes, which are adapted to engage opposite sides of the adjacent rail 3. Flexibly supported upon each of the brackets 4 is an electro-magnet 7 whose core 8 extends through the opposite ends thereof and is provided with lateral bifurcated shoes 9 which embrace and lie in close relation to the rail 3. The particular means shown for flexibly connecting the magnet 7 to the bracket 4 consists of a spring 10 which is attached at its upper end to a lateral arm 11 on the bracket 4 and at its lower end to the core 8. The lower ends of the levers 5 are respectively pivoted to the links 12 which are in turn pivoted to the triangular plate 13 of non-magnetic material, such as brass. The upper end of the plate 13 is pivoted to the lower end of the core 8 which is formed with a yoke 14, between the branches of which the plate 13 is located.

The braking mechanism comprises a mag net '7 on each side of the car, its core 8 with the laterally extending shoes 9, the rail 3 which constitutes an armature for the magnet 7, the brake shoes 6 adapted to engage the rail 3, and the link and lever connections between the core of the magnet 7 and said brake shoes. The flexible connection between the car and the magnet, through the spring 10, provides for the movement of the magnet with the car under normal conditions, and for independent movement of the ear with respect to said magnet when the movement of the magnet with the car is arrested by extraneous forces.

The shoes 9 on the core 8 of the magnet 7 have been described as bifurcated and as straddling or embracing the rail 3. To obtain the most perfect action between the magnet core and the rail 3, I prefer to form one side of the shoes 9 of a plate 15 of brass or other nonmagnetic material. This construction is clearly shown in Fig. 7 of the drawings. By the use of this plate on one side of each of the shoes 9, the magnetic attraction between said shoes and the rail 3 is prevented from producing a neutral effeet, which would be caused if both sides of these shoes were made of iron or other magnetic material.

Constructed as above described, it will be seen that under normal conditions when the car 1 is moving up and down in the elevator shaft 2 all of the parts of the braking mechanism will be carried thereby and will be in substantially the same positions as are shown in Figs. 3 and 1 of the drawing. That is to say, the magnet 7 will be held as far downwardly away from its point of attachment to the car 1 as the spring 10 will permit, and the brake shoes or gripping devices (3 will be held out of contact with the rail 3. Free movement between the shoes 9 on the magnet core 8 and the rail 3 will also be permitted. If, however, the magnet 7 be energized, a magnetic circuit will be closed through the core 8, the shoes 9 thereon, and the rail 3, substantially as shown by the arrows in Fig. (3 of the drawing. The shoes 9 will thus be drawn toward the outer edge of the rail 3 and also toward one face of the same. The result will be that the magnet 7 through its core will be locked to the rail 3 and held against upward or downward movement. If the car 1 be descending, due to a breakage of the hoisting cable or from any other cause, its downward movement will be continued slightly independent of the magnet. The links 12 will then be thrown outwardly, imparting a corresponding movement to the lower arms of the levers 5, and the upper arms of said levers will be moved inwardly forcing the brake shoes 6 into engagement with the rail 3 with sufficient force to arrest the further down ward movement of the car.

Under some conditions it is advisable to provide means for checking or arresting the movement of the car when it attains :1 dangerous rate of speed in an upward direction. This is particularly true of elevators of the plunger type. In order to provide for this, the construction shown in Fig. 5 of the drawing has been designed, this construction operating upon the same principle as that heretofore described, but providing for the application of the braking mechanism when a dangerous speed is attained in either direction. In this construction I employ, in addition to the magnet 7, with its core 8 supported by the spring 10 upon the bracket 1 on the car and connected through the links 12 and levers 5 with the brake shoes 6, a supplemental bracket 15, which is secured to the car at the point below that to which the bracket 4 is attached, and mount thereon the levers 16 which are similar to the levers 5, but reversely disposed, and connect the lower arm of said levers with supplemental brake shoes 17 cooperating with the rail 3, and also connect the upper arms of the levers 16 with the links 18 which are in turn pivoted to the brass plate 13. If the car be descending and the magnet 7 be energized, the operation of this form of my device is the same as that heretofore described; that is, the upper brake shoes 6 are forced into gripping engagement with the rail 3 with sufiicient force to stop the movement of the car. If, however, the car be moving upwardly, the action as follows: When the magnet 7 is energized the core 8 thereof is held against or locked to the rail 3, in the manner heretofore described, and the car continues its upward movement independently of said magnet. As the plate 13 is also held against move ment, the links 18 are thrown outwardly, a similar movement is imparted to the up per arms of the levers 1G and the lower arms of said levers are moved inwardly, forcing the brake shoes 17 into engagement with the rail 3 and thereby arresting or checking the further upward movement of the car.

It is intended that the braking mechanism described shall be automatically thrown into operation upon the breakage of the hoisting cables or plunger-s and also when the speed of the car exceeds a predetermined value in either direction. To provide for the first of these actions I propose to employ a normally open switch controlling the circuit through the magnets 7, said switch being held in its open position by the hoisting cable or plunger, but adapted to be automatically closed when said cable or plunger becomes inoperative. One form of switch suitable for this purpose has been illustrated in Fig. 8 of the drawing, the same being shown applied to the hoisting cable 19 and mounted on the car 1 at a point adjacent thereto. This switch comprises the spring fingers 20, 21, mounted upon the insulating block 22 and connected respectively with the wires of the circuit through the magnets 7. Cooperating with the spring fingers 20 is a metallic contact piece 23 adapted to bridge the circuit between or electrically connect the spring fingers 20, 21, when in retracted position. The contact piece 23 is mounted on a lever 24 fulcrumed upon a bracket arm 25 on the car 1 and normally urged downwardly through the action of a spring 26. The outer or free end of the lever 24 is provided with a yoke 27 which embraces and bears against the cable 19 when the parts of thedevice are in their normal operating positions. hen the cable 19 is intact there is of course a heavy tension thereon, and, with the yoke 27 bearing against it, as shown in Fig. 8, the lever 24 is held in its raised position with the contact piece 23 out of engagement with the spring fingers 20, 21 of the switch. In the event of a breakage of the cable 19, the tension thereon is relieved and the same no longer acts to resist the movement of the lever 24. The spring 26 there fore acts to draw the lever 24 downwardly, forcing the contact piece 23 into engagement with the spring fingers 20, 21, and closing the circuit through the magnets 7. WVhen this takes place the braking mechanism acts to arrest the movement of the car in the manner heretofore described.

In order to provide for stopping a car when the speed of the same increases beyond a predetermined limit, I provide a switch which is thrown into operation to close the circuit through the magnets 7, through the action of a governor 28 mounted at some suitable point on the car. Any suitable form of governor may be employed, but the particular one shown in the drawing comprises the shaft 29 having a sheave 30 on one end thereof which is rotated, during the movement of the car 1 up and down, through the action of the weighted rope or cable 31 mounted in the shaft and passing around said sheave. On the shaft 29 is a fixed collar 32 and a loose collar 33, the same being connected to each other through the links 3435 and the balls or weights 36. Connected with the movable collar and operated thereby is a trigger 37 shown in the form of a bell crank lever fulcrumed to the car at 38. The switch which is controlled by the governor 28 may be of any suitable form but has been shown as comprising the spring fingers 39, 40, included respectively in the electric circuit through the magnets 7. adapted to be electrically connected with each other by a contact piece 41 which is normally urged toward said fingers by the spring 42. Said cont-act piece, however, is provided with a central extension or rod 43 which is normally engaged by the free end of the trigger 37, the latter serving to hold said contact piece 41 out of engagement with the spring fingers 39, 40. The action of this device, it is thought, will be readily understood. WVhen the car 1 is at rest or is moving in the shaft at a normal rate of speed,

the parts remain in the positions shown in Figs. 1 and 8 of the drawings. \Vhen, however, the speed of the car increases beyond a predetermined limit, to which the governor may be readily adjusted, the balls 36 of the governor are thrown outwardly by centrifugal force far enough to trip the switch and throw it into operative position. That is to say, the collar 33 is drawn toward the These spring fingers are collar 32, thereby rocking the trigger 37 and disconnecting the free end thereof from the rod or extension 43. The spring 42 then acts to force the contact piece 41 into engagement with the spring fingers 39 and 40 and the electric circuit is thereby closed through the magnets 7. These are thereby energized and the braking mechanism is thrown into operation to arrest the movement of the car, in the manner above described. The electric circuit through the magnets 7 may also be closed for the purpose of arresting the movement of the car by hand operated switches 44-4546, located at any suitable points. One of these switches may be located within the car for the use of the operator, another may be located at a different point in the car for operation by a passenger, and the third may be located at a point outside the car for operation by any one noticing a dangerous speed condition existing.

It may happen that through one or the other of the instrumentalities described the movement of the car may be stopped at a point between fioors. In order to provide means for slowly and safely lowering the car to a convenient landing place for the passengers therein, 1 provide in the circuit through the magnets 7 a rheostat 47 by means of which the resistance in the circuit may be increased for the purpose of par tially deenergizing the magnets 7, thereby decreasing the effective action of the braking mechanism and allowing the car to gradually slip from the point where it originally stopped to the next floor. This rheostat may be of any suitable construction. In the drawings 1 have illustrated the same as consisting of the resistance coils 4S and a hand operated lever 49 adapted to be moved for the purpose of throwing into the circuit a greater or less amount of resistance. The normal 110-resistance position of the lever 49 is as shown in Fig. 8 of the drawings and the same is held in this position by a spring 50 and a stop 51, against which the lever 49 bears. It willv be obvious that by moving the lever 49 to the left resistance may be cut into the circuit to a greater or less degree, the effect of which is to correspondingly deenergize the magnets 7 and reduce the effective action of the braking mechanism.

The electric current for energizing the magnets 7 may be derived from a storage battery 52 located at any convenient point, or from any other source. lilnder normal conditions the switches 44, 45, 46, 3941 and 20-23, are open and there is consequently no How of current through the magnets 7. The parts of the braking mechanism. are therefore in the positions in which they are shown in the drawings, and the car 1 is free to move up or down in the shaft 2. If, however, the switch 2023 is closed in the manner described, by a breakage of the hoisting cable 19, the circuit through the magnets 7 will be closed over the following path: battery wire 53, rheostat 47, wires al, 56, 57 and 58, finger 21, contact piece 23, finger 20 and wires 59 and 60, back to the battery. It the switch 39 t1 be closed through the action of the governor 29 due to excessive speed, in the manner described, the circuit through the magnets 7 will be closed over the following path: battery 51, wire rheostat 1L7, wires 56 and 57, finger 39, contact piece -il-l finger and wire (30, back to the battery. If any one of the switches ll, t5, ill, be manually closed, the flow of current will be over the following path: battery wire rheostat JCT, wires 54, 57 5(3 and 61, and switch 44, 4-5 or t6 to the wire 60, and thence back to the battery.

Having now described my invention, what I claim is:

1. The combination with an elevator car, of an electro-magnet carried thereby, one of said parts being capable of movement inde pendent of the other, an armature for said magnet serving to produce an independent movement of one of said parts with respect to the other when the magnet is energized, and braking mechanism connected with the car and magnet and thrown into operation upon the movement of one of said parts independently of the other.

2. The combination with an elevator car, of an electro-magnet carried thereby, one of said parts being capable of movement independent of the other, a fixed part constituting the armature of said magnet, and serving to hold the magnet against movement when the latter is energized, and braking mechanism connected with said car and magnet and thrown into operation when the car moves independently of said magnet,

The combination with an elevator car, of an electro-magnet fiexibly connected therewith and carried thereby, a fixed armature therefor acting to arrest the movement of the magnet when the latter is energized, and braking mechanism connected to the car and magnet and thrown into operation upon the movement of the car with respect to the magnet.

l. The combination with an elevator car, of a spring-supported electro-magn-et carried thereby, a fixed armature for said magnet located outside the car and acting to arrest the movement of the magnet when the latter is energized, and braking mechanism connected to the car and magnet and thrown into operation upon the movement of the car with respect to the magnet.

5. The combination with an elevator car, of an electro-magnet carried thereby, one of said parts being movable independently of the other, a fixed armature for said magnet serving to hold the magnet against movement when the latter is energized, and braking mechanism comprising gripping devices, levers fulcrumed to the car for operating the same, and connections between said levers and said magnet, whereby said gripping devices are thrown into operation when said magnet is energized and independent movement of the car with respect to said magnet is effected.

(3. The combination with an elevator car, of a spring-supported clectro-magnet carried thereby, a fixed armature for said magnet serving to arrest the movement of the magnet when the latter is energized, and braking mechanism comprising gripping devices, levers fulcrumed to the car for actuating the same, and connections between said levers and said magnet, whereby said gripping devices are thrown into operation when said magnet is energized and independent movement of the car with respect to said magnet is effected.

7. The combination with an elevator car, of an electro-magnet, a spring connecting said magnet with the car and supporting the same, a fixed armature for the magnet acting to arrest the movement thereof when the same is energized, and braking mechanism comprising gripping devices, levers fulcrumed to the car for operating the same, and link connections between said levers and said magnet, whereby said gripping devices are thrown into operation when said magnet is energized and independent movement of the car with respect to said magnet is effected.

S. The combination with an elevator car, of an electro-magnet flexibly connected therewith and carried thereby, the core of said magnet being provided with laterally extending shoes, a fixed armature for said magnet extending longitudinally of the elevator shaft and forming part of a closed magnetic circuit through said magnet when the latter is energized, and braking mechanism connected to the car and magnet and thrown into operation upon the movement of the ear with respect to the magnet.

9. The combination with an elevator car, of an electro-magnet flexibly connected therewith and carried thereby, the core of said magnet being provided with laterally extending shoes, fixed armature for said magnet extending longitudinally of the elevator shaft and forming part of a closed magnetic circuit through said magnet when the latter is energized, braking mechanism comprising gripping devices, levers fulcrumed to the car for operating the same, and link connections between said levers and said magnet, whereby said gripping devices are thrown into operation when said magnet is energized and independent movement of the car with respect to said magnet is effected.

10. The combination with an elevator car, of an electro-magnet, comprising a core having laterally extending bifurcated shoes and a coil surrounding said core, a spring connecting the car with said magnet for supportin the latter and providing for independent movement of the car with respect thereto, a fixed armature extending longi tudinally of the elevator shaft, the same being embraced by the bifurcated shoes on the magnet core, and braking mechanism connected to the car and magnet and thrown into operation upon the movement of the car with respect to the magnet.

11. The combination with an elevator car, of an electro-magnet, comprising a core having laterally extending bifurcated shoes and a coil surrounding said core, a spring connecting the car with said magnet for supporting the latter and providing for independent movement of the car with respect thereto, a fixed armature extending longitudinally of the elevator shaft, the same being embraced by the bifurcated shoes on the magnet core, and braking mechanism, comprising gripping devices, levers fulcrumel to the car and pivoted to said gripping de vices for actuating the latter, and link connections between said levers and said magnet, whereby said gripping devices are thrown into operation when said magnet is energized and independent movement of the car with respect to said magnet is effected.

12. The combination with an elevator car, of an electro-magnet flexibly connected therewith and carried thereby, a fixed arma ture therefor acting to arrest the movement of the magnet when the latter is energized, and braking mechanism, comprising two sets of gripping devices and link and lever connections between the respective gripping devices and said magnet, whereby one set of said gripping devices will be thrown into operation upon the movement of the car in one direction independently of the magnet, and the other will be thrown into operation braking mechanism connected to the car and.

magnet and thrown into operation upon the movement of the car independently of the magnet, a switch for closing an electric circuit through said magnet, and means automatically thrown into operation upon derangement of the hoisting mechanism for actuating said switch.

14. The combination with an elevator car, of an electro -1nagnet flexibly connected therewith and carried thereby, a fixed armature therefor acting to arrest the movement of the magnet when the latter is energized, braking mechanism connected'to the car and magnet and thrown into operation upon the movement of the car independently of the magnet, a switch for closing an elec tric circuit through said magnet, and means automatically thrown into operation when the car exceeds a certain predetermined speed for actuating said switch.

15. The combination with an elevator car, of an electro magnet flexibly connected therewith and carried thereby, a fixed armature therefor acting to arrest the movement of the magnet when the latter is energized, braking mechanism connected to the car and magnet and thrown into operation upon the movement of'the car independently of the magnet, an electric circuit through said magnet, a switch for closing said circuit, and a rheostat included in said circuit for cutting in resistance and permitting the ear to be slowly lowered from one point to another.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

HOVARD M. P. MURPHY.

WVitnesses WM. M. STOCKBRIDGE, WALDO M. CHAPIN.

Images