US1258127A

US1258127A - Safety-stop for elevators.

Info

Publication number: US1258127A
Application number: US4967115A
Authority: US
Inventors: Nils O Lindstrom
Original assignee: ALONZO B SEE
Current assignee: ALONZO B SEE
Priority date: 1915-09-09
Filing date: 1915-09-09
Publication date: 1918-03-05
Anticipated expiration: 1935-03-05

Description

I N.- O. L'INDSTROM.

SAFETY STOP FOR ELEVATORS APPLICATION FILED SEPT. 9. 1915.

Patented Mar. 5, 1918.

3 SHEETSSHEET I N. O. LINDS'IROM.

SAFETY STOP FOR ELEVATORS.

APPLICATION men SEPT. 9 1915'.

Patented Mar. 5,1918.

3 SHEETS-SHEET 2.

N. O. UNDSTROM.

SAFETY STOP FOR ELEVATORS.

APPLICATION FILED SEPT. 9.1915.

avwewhoz Patented Mar. 5, 1918.

Unrrnn srairns ran NILS O. LINDSTRGIVI, OF NUTLEY, NEW JERSEY, ASSIGNGR T ALO'NZO B. SEE, OF BROOKLYN, NEW YORK.

SAFETY-STOP FOR ELEVATORS.

Application filed September 9, 1915.

To all whom it may concern:

Be it known that I, NrLs O. LINDSTROM, a citizen of the United States, residing at Nutley, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Safety-Stops for Elevators, of which the following is a full, clear, and exact specification.

This invention relates to safety stops for elevators 0f the class in which an abnormal invention are pointed out in the following specification and in the appended claims.

In the accompanying drawings Figure 1 is an elevation, partly in section, of the lower portion of an elevator car, and of my safety appliance, the solenoid being shown conventionally. Fig. 2 is a plan view, partly in section, of one of the guide rails, one of the gripping jaws and mechanism for operating the same. Fig. 3 is a sectional view, on the line Y Y of Fig. 2. Fig. 4 is a sectional view on the line X X of Fig. 3. Fig. 5 is a detail elevation of a modification of the means for reopening the gripping jaws and rewinding the cable 15 on the drum 14. Fig. 6 is a section on the line V V of Fig. 5.

Similar characters of reference refer to similar parts throughout the accompanying drawings, in which 1 is the lower portion of an elevator car, 2 the guide rails in the elevator shaft, 3 gripping jaws hinged at 4 and held in the open position by springs 5. The inner portions of the jaws are provided with anti-friction rollers 6, and between the jaws are wedges 7, retained in position in guides 8. Each of these wedges is provided with a tail piece 9, the inner end 10 of one of which is provided with a right screw-thread and the inner end 11 of the other with a left screw-thread. Each of the tail pieces is provided with a cross head 12, sliding on guides 13, which serves to prevent the rotation of the wedge. Mounted underneath the bottom of the car is a drum 14 which is interiorly provided with right and left screw threads,

Specification of Letters Patent.

Patented Mar. 55,1918. eria1No.49,671.

to receive the screw-threadedends of the tail pieces of the wedges. One end of a cable or cord 15 is secured to the drum 14 at 16. The cord 15 is wrapped or wound about the drum and is then passed around the sheaves 17 and between the sheaves 18, all of which sheaves are mounted on the car. This end of the cord or cable is then secured at 19 to an endless cord or cable 20, which passes over a stationary sheave 21, mounted near the top of the elevator shaft and around a weighted sheave 22, located near the bottom of the elevator shaft. Mounted in operative relation to the sheave 21 is a governor 37. 'Mounted in operative position with reference to the cable is gripping mechanism, consisting of stationary members 23 and levers 24 pivoted at 25, and connected at their upper ends to the core pieces 26 of the solenoid 27, by which they are held out of engagement with the cable 20 against the tension of the springs 28, whenever the solenoid is energized. In the circuit CC,-designed to supply electric current to energize the solenoid 27 is a switch 29, which is held in closed position by the latch 30. In the same circuit and mounted in the car within reach of the operator is an emergency switch 31, adapted to be manually operated by the operator of the car. The governor 37 is provided at its upper end with a guide post 32, upon which is mounted a sleeve 33, adapted to be moved up and down as the speed of the governor increases or diminishes. In operative relation to said sleeve is a plunger 34, which is adapted to trip the latch when the governor 22 is rotated at a predetermined speed. Mounted on the drum 14 is a Worm gear 35, which is adapted to be operated by a removable worm shaft 36, inserted into the guideway 28, so

as to open the gripping jaws and replace I the mechanism in the inoperative position shown in Fig. 1. I

In order to close the switch 29, I have provided a solenoid 40. The circuit t. t. which is designed to supply current for the pur- 7 pose of energizing the solenoid '40, is normally open, but may be closed by closing the button switch 41, carried by the elevator.

In the modification shown in Figs. 5 and. 6, the guideway 38 is hinged at 42, so that the worm shaft 36 may be swung out of and into engagement with the worm gear 35. When in engagement it is locked in position by the latch 43, hinged at 4A. The core piece 45 of the solenoid 46 is secured to the latch 47. The latch is also provided with an arm 48, in the end of which is mounted a friction roller 19. When the solenoid is actuated, the latch 43 will be lifted out of engagement with the catch on the guideway and carrying with it the arm 48 which, as it rises, will force back the guideway 38 and carry with it the worm shaft 36, until the worm shaft 36 is out of engagement with the worm gear 35, nor may the worm shaft 36 be again swung into engagement with the gear 35, until the solenoid 46 has been deenergi'zed.

An electric "circuit ER is designed to sup ply electric current for the purpose of energ ing the solenoid 46. The circuit is closed by a switch 51, which is carried by the switch 29, the construction being such that when the switch 50 is closed the switch 29 is open and when the switch 50 is open the switch 29 is closed.

T he operation of my device is as follows:

Normally the cable 20 is free to run over the

sheaves

21 and 22, and when so running the load on the cable 15 is insufficient to operate the safety device. lVhen, however, the speed of the car and the corresponding speed of the cable 20 and the governor 37 is increased to the speed at which the latch 30 has been adjusted, the governor 37 will trip the latch 30. and open the switch 29, thereby cutting off the current from the solenoid 27, which permits the springs 28 to cause the levers 24 to grip the cable 20 and hold it stationary. The movement of the car then unwinds the cable 15 on the drum 14:, causing the drum to rotate and draw the wedges between the inner jaws of the mechanism, thereby causing the gripping jaws to gradually and gently grip the guide rails until the car is brought to a stop. It isapparent that the distance which the car is permitted to move after the safety appliance is thrown into operation is dependent upon the pitch of the threads on the tail pieces 9 and the diameter of the drum. The switch 31 is provided so that the operator of the car may manually break the solenoid circuit and throw the stop mechanism into operation whenever an emergency arises, without waiting for the car to attain an undue speed. lVhen the car has been brought to rest, the gripping jaws may be opened and the mechanism for operating them reset by inserting the worm shaft 86 into the guideway 38 and rotating it until it seats in the base of said guideway. Further rotation of the worm shaft will rotate the drum 1%, rewind the cable 15, force back the wedges 7, and permit the springs 5 to open the gripping jaws. The rotation of the worm shaft is then continued until it may be Withdrawn without closing the gripping jaws.

The circuit 6. t. may then be closed by means of the button switch 41 and the solenoid l0 energized, causing it to close the switch 29.

TV he "e the modification shown in Figs. 5 and 6 is employed, whenever the circuit energizing the solenoid 21 is broken and the safety stop device is in operation, the switch 50 is closed, the solenoid 46 actuated, the latch 43 lifted out of engagement with the catch 50, and the worm shaft 36 forced and held by the arm 48 out of engagement with the worm gear 35, so that the operator cannot release the gripping jaws 3 from the guide rail 2 until the switch 29 has been closed and the whole safety stop mechanism thereby reset so that it will again be ren dered operative if the car should attain an undue speed after the gripping jaws 3 have been released.

Having described my invention, I claim- 1. A safety stop for elevators, comprising brake mechanism having gripping members and automatic means for operating the same including a trip, means for releasing said gripping members and automatic means for preventing the operation of the means for releasing said gripping members until the trip has been reset.

A safety stop for elevators, comprising brake mechanism and automatic means for operating the same, manually controlled means for releasing the brake mechanism and automatic means for preventing the operation of the means for releasing the brake mechanism until the automatic means for operating the brake mechanism has been adjusted, so that it is again operative.

3. A safety stop for elevators 'comprising gripping j aws, automatic means for closing said gripping jaws and manual means carried by the car for opening said gripping jaws and electric means for resetting said automatic mechanism.

Signed at New York city in the county of New York and State New York, this 31 day 'of August, 1915.

NILS O. LINDSTROM.

Witnesses:

CATHARINE M. BYRNE, BENJAMIN T. ABRAMS.

Copies 01 this patent may be obtained for five cents each. by addressing the Commissioner 01' Patents,

Washington, D. G.