US1738214A

US1738214A - A coepoeatioh

Info

Publication number: US1738214A
Authority: US
Publication date: 1929-12-03
Anticipated expiration: 1946-12-03

Description

1929. E. B. THURSTON 1,738,214

DETERMINED TRAVEL SAFETY CONTROL Filed May 20, 1925 T E S era ERNEST B. THURSTON, F TOLEIDG, OHIO, ASSIGNOR T0 THE HA'UGHTQI'I a MACHINE COMPANY, 01F TOLEDO,

OHIO, A GORPORATION OF 015.10

DETERMINED TRAVEL SAFETY CONTROL Application filed May 20,

This invention relates to travel control means for elevators.

This invention has utility when incorporated in traction elevators for rendering the drive ineffective at predetermined point as when the travel limit is reached or approached by the car or its counter-weight.

Referring to the drawings:

Fig. 1 shows an embodiment of the invention for the up and down control limits of the car;

Fig. 2 is a detail view of one of these safety controls for effecting slippage or loss of traction; and

Fig. 3 is an end view of the grip of the control of Fig. 2.

Motor 1 is shown as having driving shaft 2 effective through worm 3 for driving worm wheel l on shaft 5 carrying traction drum 6 u about which extends cable having reach 7 to counter-weight 8 and reach 9 to elevator car 10, which car is movable up and down in elevator shaft 11 between

landings

12, 13, 1 1.

In the upper portion of the elevator shaft 11 fixed fulcra 15 are provided for levers 16 carrying counter-weights 17 for holding jaw 18 normally away from a descending reach of a cable. Opposing the jaw 18 is fixed jaw 19. As the counter-weight 8 ascends to approach a limit of travel, this device may be effective for holding the car 10 against being driven into a final hatch limit at the bottom of the elevator shaft 11, for this counter-weight 8, while ascending, strikes the lever 16 and thus rocks such lever 16 to cause supplemental arm 20 to act through spring 21 to yieldably urge the jaw 18 against the fixed jaw 19 to grip cable reach 9. The load of the car 10 is thus transferred from the drum 6 to this

grip

18, 19. The continual driving action of the motor 1 has a tendency to crowd the cable from reach 7 toward the reach 9. However, as there is thus relatively little load upon the reach 9 at the drum, the discrepancy between the loads upon the two reaches is so great that the drum slips beneath the cable and does not drive it further. This means that in those instances wherein the motor 1 may continue to drive after the elevator has reached a safety limit position, no disaster may arise there- 1925. Serial No. 31,698.

from, for the counter-weight 8 holds the cable or cables against the traction drum 6 while the

grips

18, 19, have served to relieve the drum 6 from th load opposing the counter-weight 8 to such an extent that the turning of the drum does not move the cable.

In practice, the drive cable may be effective to hold its traction in a V-groove of the traction drum when the ratio between the loads is as low as four to one. If the cable or cables be greased, this ratio drops to in the region of two to one. Wrapped cable traction may be as low as eight to one. In long elevator shafts there is a factor in changing this ratio due to the length of cable extending, in the longer reach. Such may be a factor of hazard and as herein disclosed the device is designed to become effective as to such'longer reach and not only remove the load of such reach in itself, but the load carried thereby, either the car 10 when the car has reached its down limit or counterweight 8 when the car has reached its upper limit. For example, if reach 8 has a load of one thousand pounds and reach 9 a load of four thousand pounds and the clamp on reach 9, after it is closed by the upward travel of the counterweight, allows a tension of thirty pounds to be transmitted through it to reach 9 at the driving drum, the ratio between the loads on reaches 8 and 10 becomes over to 1, so that the drum may continue to turn without moving the cable. When the actual weight of the de scending load, whether the counterweight or the car, is gradually taken up by an oil or spring buffer or other known stopping means, this invention is effective in supporting the weight of the cable and thus preventing the further lifting of the ascending load, which may occur if the entire Weight of the descending reach is suspended from the driving drum.

vV hat is claimed and it is desired to secure by United States Letters Patent is 1. An elevator installation comprising a driving drum, power means to rbtate the drum, a cable in frictional engagement with the drum and having a reach on each side thereof, a load on each reach exerting tension thereon, and a device adapted to engage a reach between its lead and the drum and lessen the tension exerted by the load upon the reach between the device and the drum and thereby lessen the friction between the drum and the cable and allow the drum to continue turning without further movement of the cable.

2. An elevator installation embodying a driving drum, power means to rotate the drum, a cable in frictional engagement with the drum and having a first reach, a car carried by said reach, said cable also having a second reach, a counter-weight carried by the second reach, and means for rendering the drum ineffective by disturbing the ratio be tween the reaches as to loading transmitted to the drum, independently of the car or counterweight.

3. An elevator installation comprising a driving drum, a cable in frictional engagement with the drum and having a reach on each side thereof, a load on each reach exerting tension thereon, a device adapted to engage a reach between its load and the drum and lessen the tension exerted by the load upon the reach between the device and the drum, and means operating the said device when the load upon the other reach arrives at a predetermined limit in its approach to the drum.

4. An elevator installation comprising a driving drum, a cable in frictional engagement with the drum and having a reach on each side thereof, a load on each reach exert in'g tension thereon, means to apply friction to a reach between its load and the drum, and a device for operating said friction means when the load upon the other reach arrives at a predetermined limit in its approach to the drum. 7

5. An elevator installation comprising a driving drum, a cable in frictional engage m'ent with the drum and having a reach on each side thereof, a load on each reach exerting tension thereon, means to apply friction to a reach between its load and the drum, and a yielding operating device for said means engageable by the load on the other reach, as it approaches the drum.

6. An elevator installation comprising an elevator shaft, a driving drum at the top of the shaft, a cable passing over the drum and having a downwardly directed reach on each side of the drum, a car carried by one reach, a counterweight carried by the other reach,and a device for each reach adjacent the drum adapted to relieve its respective reach of tension at the drum when the load of the other reach approaches the drum to a predetermined extent.

7 An elevator installation comprising an elevator shaft, a driving drum at the top of the shaft, a cable passing over the drum and having a downwardly directed reach on each side of the drum, 2, car carried by one reach,

a counterweight carried by the other reach, a

clamp for the counterweight-reach adjacent the drum, and a clamp-closing member adapted to be engaged by the car as it approaches the drum.

8. An elevator installation comprising an elevator shaft, a driving drum at the top of the shaft, a cable passing over the drum and having a downwardly directed reach on each side of the drum, a car carried by one reach, a. counterweight carried by the other reach, a clamp for the car-reach adjacent the drum, and a clamp-closing member adapted to be engaged by the counterweight as it approaches the drum.

9. An elevator installation comprising a driving drum, a cable passing over the drum and having a reach suspending and terminating at a car and another suspending and terminating at a counterweight, a device adjacent the drum adapted to sustain the weight of a reach therebelow, and means for operating said device when the load connected with its reach approaches its lower limit.

10. An elevator system comprising, two

movable bodies in the hatchway, a hoisting rope connecting said movable bodies, and a safety appliance mounted in the hatehway comprising means for gripping the hoisting rope, and means for normally retaining said gripping means in its inoperative position, said retaining means being arranged to be actuated by one of the movable bodies to cause the application of the gripping means.

11. An elevator system comprising, two movable bodies in the hat'chway, a driving sheave, roping connecting the movable bodies and passing over said driving sheave, and means cooperating with saidroping to cause the stopping of one of said bodies with substantially gravity retardation.

12. In an elevator system, a movable body in the hatchway, a hoisting drum positioned in the upper portion of the hatchway, flexible hoisting means extending from said hoisting drum to said movable body, and means mounted in the hatchway near the hoisting drum for gripping said flexible hoisting means to effect the stopping thereof.

13. In an elevator, a car, flexible means for moving the car, driving means for said flexible means, and means operative, when the car is moved to a predetermined limit, to grip and stop said flexible means regardless of continued motion of said driving means.

14. In an elevator hatchway, a moving system comprising two movable bodies, flexible hoisting means connecting said bodies, and automatic means operating directly upon upon said hoisting means to cause the stopping of a portion of said system.

15. An elevator system comprising, two oppositely movable bodies in the hatchway, flexible hoisting means connecting said movable bodies, and automatic means for grippin said hoisting means for causing the stopping of the ascending body with substantially gravity retardation.

16. An elevator system comprising, two movable bodies in the hatchway, flexible hoisting means connecting said movable bodies, and automatic means for gripping said hoisting means to cause the stopping of a portion thereoi.

17. An elevator system comprising, two movable bodies in the hatchway, flexible hoisting means connecting said movable bodies, and automatic means for gripping said hoisting means as the descending body approaches its normal lower limit.

18. In an elevator system, a movable body in the hatchway, flexible hoisting means for supporting said movable body, and automatic means mounted in the hatchway for gripping said hoisting means to effect the stopping thereof.

19. In an elevator system, a movable body in the hatchway, a hoisting drum positioned in the upper portion of the hatchway, a hoisting rope extending from said hoisting drum to said movable body, means mounted in the hatchway near the drum for gripping the rope and automatic means for operating said gripping means when said body descends to a predetermined point.

In Witness whereof I al'fix my signature.

ERNEST B. THURSTON.