US1864588A

US1864588A - Automatic reset safety device

Info

Publication number: US1864588A
Application number: US480095A
Authority: US
Inventors: Dunlop James
Original assignee: Westinghouse Electric Elevator Co
Current assignee: Westinghouse Electric Elevator Co
Priority date: 1930-09-06
Filing date: 1930-09-06
Publication date: 1932-06-28
Anticipated expiration: 1949-06-28

Description

June 28, 1932. J. DUNLOP AUTOMATIC RESET SAFETY DEVICE Filed Sept. 6, 1930 INVENTOR James flan/op ATTOiQNEY Patented June 28, 1932 UNETED STATES PATENT pm;

JAMES D'U'NLOP, OF PARK RIDGE, ILLINOIS, ASSIGNOE To WESTINGHOUSE ELECTRTC ELEVATOR COMPANY, A C QIRPORATION OF PENNSYLVANIA AUTOMATIC RESET SAFETY DEVICE Application filed September 6, 1930. Serial No. 480,095.

through the floor of the elevator carto re-.

wind the safety cable on the drumand withdraw the safety jaws from the rails. Hence,

3 the setting of the conventional safety-grip.-

device causes great inconvenience and loss of time before the elevator can be restoredto service. v v

It is an object of my invention, accordingly, to provide for the automatic resetting of the elevator safety device whereby the operator is enabled to promptly restore the elevator car to service after the safety device has set.

It is also an object of my invention to provide means whereby the operator of an ele+ vator car will be enabled to reset the safety device. after it has been actuated, by merely reversing the direction of'travel' of the car and causing it to move in the opposite direction. v a

In accordance with my invention, I provide two cables which are wound on the safety drum in opposite directions. One of these cables passes around an idler pulley on the car and extends upwardly. for attachment to the governorrope at a point adjacent to, or above, the elevator car. Thislcable is equivalent to the usual safety cable and is-elfective to apply the safety device to grip the rails and stop the car when unreeled in the usual manner. The other-cablepasses around an idler pulley on the car and extends downwardly for attachment to the governor rope at a point somewhatbelo'w the car. Since this cable is wound on the safety drum in a direction opposite to that, in which the first cable is wound, it is effective when unreeled to withdraw the rail-gripping jaws, rewindthe first safety cable and reset the safety device. The

operator may accomplish this'operationmere ly by starting the car upwardly.

- The governor rope must .be locked securely, while the resetting operation is being carried out, and, since the regulargovernor ropegripping jaws are only effective to prevent downward movement of theadj acent portion of the governor rope, I provide additional rope-clamping means to be rendered effective by the operation of the safety device.

The lnvention itself, however, both' as to its organization and-its method ofoperation, together with additional objects and advantages thereof, will best be understood from, the, following description of a specific embodiment, when read in conjunction with the accompanying drawing,in which Figure 1 is a diagrammatic-view'of. an

elevator system embodyin my invention," Fig. 2 is a detail view s owing the safety cablefdrum providedwith two cables wound in opposite directions,

Fig. 3is a plan view, partly sectional, taken on line IIIIII of Fig. 4', and Fig. 4 is an enlarged side elevational view partly in section taken on line IVIV of Fig.1.

Referring to the drawing, the apparatus shown Fig. 1 comprises an elevator car C which is'supported by a hoist cable Ca passing over ahoist sheave S to a counterweight CWT, in the usual manner. The hoist sheave S may be driven by an elevator motor (not shown) ,which is controlled andoperated in any well known manner. 1 v

A governor rope 11' passes over a sheave 12 above the hatchway and'under avwei'ghted idler sheave 13 at the bottom of the hatchway.

A weight 14 isattached to the idler sheave 13 andserves to automatically tension the rope 'll'and to take up any slack. A stationarvpawl 15 cooperates with teeth 16 on the side of the=clevis-17, therebypermitting the sheave 13 to move freely downwardly but preventing its movement upwardly. The rope 1l.will, at all times, be automatically tensionedby "the weighted sheave 13 which cannot be lifted by the rope. I

Attached to-the rope 11 is a Mime ball 18 which is detachably secured to the carMC between a pair of clamps 19 and which are tensioned by compression springs 21and 22. The tension-on the

clamps

19 and 20 may be adjusted by adjusting the compression on the

springs

21 and 22, and is preferably adjusted to hold the Mini ball 18 during the normal travel of the elevator car up and down the hatchway, whereby the governor rope 11 moves and drives the governor sheave 12 at speeds corresponding to the speed of the car. The clamps are pivotally mounted on a standard 24 which may be secured to the car in any suitable manner, as by a bracket 25. j

A circuit interrupter, which may also be mountedon the bracket 25, comprises a standard 26 which pivotally supports a bell-crank 27 having a contact 28 at the extremity of one arm thereof and a roller 29 at the extremity of the other arm. A stationary contact 31 is mounted on the bracket 25 in cooperative relation to. the contacti28 carried by the pivoted bell-crank .arm, and a compression spring-32 isinterposed between the bracket 25 and the contact arm ofthe pivoted bellcrank 27 for the purpose of separating the contacts and interrupting the circuit connected therethrough.

The roller'wheel29 is so disposed that the Mini ball 18-is in abutting relation thereto when it is clamped between the springpressed clamps 19 and-20 to thereby normally hold the

contacts

28 and 31 in engaging relation. The operation of'the circuit interrupter and-the purpose of the circuit controlled thereby will be subsequently set forth.

The elevator car carries the usual safety device comprising jaws which grip the guide rails (not shown). to stop the car when a safety cable 35 is unreeled from a safety druni36 in the usual'r'nanner. The cable 35 is wound on the drum 36 (shown in Fig. 2) in such direction that, when the cable is unreeled,it will cause the drum to rotate in the proper'direction-to force the threaded shafts 37. and wedges 38 apart, thereby applying the safetydevice in a well known manner. The safetycable passes around an idler'pulley 39 and extends upwardly to the Minie ball 18 where it is attached to therope 11. T In accordance with my invention, I provide a second cable 41 which is so wound onthedrum 36' that, when it is unreeled therefrom, it will cause rotation of the drum in a direction opposite to that caused by unreeling the safety cable 35. In other words, the 'unreeling of cable 41will cause rotation of'the drum 36 in a direction to rewind cable 35 on the drum and retract the threaded shafts 37, thereby resettingthe safety device.

7 As shown inFig. 1', the resetting cable 41 extends around an idler pulley 42 and downwardly for attachment to the rope 11 at a point below the elevator, in any suitable manner.

Associated with the sheave 12 is a speedresponsive device, such as a governor 42, which is driven thereby at speeds proportional to the speed of the elevator car up and down the hatchway. A pair of ropegripping jaws 43 and 44 are pivotally mounted on opposite sides of'the rope 11, and are controlled by the governor through the medium of the interconnected link 45 and the pivoted lever arm 46. The governor actuates the rope-gripping jaws to a position to grip the rope 11 when the speed of the elevator car C becomes excessive. If the adjacent governor rope 11 is moving downwardly when the jaws are moved into engagement therewith, the. rope will be locked, and further movement thereof will be prevented.

Mounted adjacent to the governor rope 11, I have also provided an electromagnetically controlled rope-gripping device comprising a'stationary gripping surface or jaw 47 and a slidably mounted, spring-pressed ropegripping 'aw 48 mounted at the opposite side of the, rope 11. An electromagnet 49 is normally energized for maintaining the slidable rope-gripping jaw disengaged from the rope.11, in opposition to the spring 51. When the electromagnet 49 is deenergized, the spring 51 pushes the slidable member 48 toward the rope which is thereby gripped firmly against the stationary gripping surface 47. This rope-gripping device is effective to grip and hold the rope, irrespective of its direction of motion.

'The electromagnet 49 is normally energized through a circuit comprising a suitable source of current 52, conductor 53, electro-" magnet 49, conductor 54,

contacts

31 and 28 on the car C, conductor 55 and the source of current 52. Since the

contacts

28 and 31 are maintained closed so long as the Mini ball 18 is secured to the car C by the springpressed clamps '19 and 20, the circuit for the electromagnet will be normally completed, and the electromagnet will be energized to hold the slid'able spring-pressed member 48 away from the governor rope. It is to be understood that the'source of current 52 may be any suitable or convenient source. v

My invention is best understood, however, when considered with reference to an assumed 7 operation thereof Assuming that the car C,

29 is released, and the

contacts

28 and 31 separate, thereby interrupting the circuit and deenergizing the electromaget 49. The slidable member 48, having been released, the spring 51 will force it toward the rope 11 which will be gripped between it and the stationary gripping surface 47.

In order to reset the safety and restore the car to service, it is only necessary to start the car in the opposite direction. Since the governor rope 11 is locked between gripping jaws 4:7 and 48 and its lowerend is latched by the sheave 13 and pawl 15, the lower end of the reset cable 41 will thereby be held stationary and will be unreeled as the car moves upward. As previously set forth, the rotation of the safety drum 36 caused by unreeling cable 41 will be in a direction to cause the retract-ion of the threaded shafts 37 and will release the safety device. The safety cable 35 will be simultaneously rewound, and the safety device will be restored to its original condition for normal operation of the elevator car. When the Mini ball is reengaged by the

clamps

19 and 20, the wheel 29 will be reengaged to thereby close the contacts 28 and y 31. The closure of

contacts

28 and 31 will completethe energizing circuit for the electromagnet 49 which will pull the springpressed gripping member 48 back to disengaging relation, and the governor rope will again run free. The elevator safety and actuating system will, therefore, be restored to normal operating condition.

It will be seen that I have provided an elevator safety device which, when actuated to stop the car, may be promptly restored to normal operating condition by merely causing the car to move in the opposite direction.

I do not wish tobe restricted to the specific structural details and arrangement of parts herein set forth, inasmuch as various modifications thereof may be employed without departing from the spirit and scope of my invention. I desire, therefore, that only-such limitations shall be imposed as are necessitated by the prior art and the scope of the appended claims.

I claim as my invention:

1. The combination with an elevator system comprising an elevator car, a safety device operable by unreeling a safety cable from a safety drum, means responsive to overspeeding of the elevator car for unreeling the safety cable to set the safety device and stop the car, of means for automatically rewinding the safety cable and releasing the safety device when the elevator car moves in the opposite direction.

2. The combination with an elevator system comprising an elevator car, a safety de vice operable by unreeling a safety cable from a safety drum, means responsive to overspeeding of the elevator car for unreel and stop the car, of means for automatically rewinding the safety cable and. releasing the safety'device when the elevator carmoves in the opposite direction, said means comprising a-se'cond cable wound on the safety drum in the opposite direction relative to said first cable.

3. In combination, an elevator car operable up and down a hatchway, a safety device carried by the car including a safety drum and an actuating cable'wound thereon for actu atingthe same, a speed-responsive device, agovernor-rope detachably secured to said car and attached to said safety cable for operating said speed-responsive device at speeds corresponding to the speed of the car up and down the hatchway, means actuated by said speed-responsive device when the car attains a predetermined speed for gripping and holding said governor rope, whereby the cont1nued movement of the car is rendered effective to unreel the safety cable and apply the safety device, and a second cable wound onsaid safety drum in the op osite direction and attached to said rope, whereby the actuating cable may be rewound and the safety be reset by moving the elevator car in the opposite direction.

l, In combination, an elevator car operable up and down a hatchway, a safety device carried by the car including a safety drum and an actuating cable wound thereon for actuating the same, a speed-responsive device, a governor rope detachably secured to said car and attached to said safety cable for operating said speed-responsive device at speeds corresponding tothe speed of the car up and down the hatchway, means actuated by said speed-responsive device when the car attains a predetermined speed for gripping and holding said governor rope, whereby continued movement of the car is rendered effective ping means for holding the rope while the safety-actuatmg cable is being rewound and,

the safety device released. v

5. In combination, anelevator car operable up and down a hatchway, a safety device carried by the car including a safety drum and an actuating cable woundthereon for actuating the same,-a speed-responsive device, a

governor rope detachably secured to said car and attached to said safety cable for opera ting said speed-responsive device at. speeds corresponding to the speed of the car up and down the hatchw'ay,-means actuated by said speed-responsive device when the car attains a predetermined speed for gripping and holding said governor rope, whereby the continned movement of the car is rendered effective to unreel the safety cable and apply the safety device, a second cable Wound on said safety drum in the opposite direction and attached to said rope, whereby the actuating cable may be rewound and the safety be reset by moving the elevator car in the opposite direction, an additional electromagnetic' rope-gripping device operable to grip and hold the governor rope, irrespective of its direction of movement, and circuit-controlling means responsive to the release of the governor rope from the car for actuating said electromagnetic rope-gripping device.

In testimony whereof, I have hereunto subscribed my name this 22nd day of August,

JAMES DUNLOP.