US635679A

US635679A - Speed regulating or controlling device for elevators.

Info

Publication number: US635679A
Authority: US
Inventors: Edward P Forbes
Original assignee: Individual
Current assignee: Individual
Priority date: 1899-02-20
Filing date: 1899-02-20
Publication date: 1899-10-24
Anticipated expiration: 1916-10-24

Description

Patented Oct. 24, |899.

E. P. FORBES. SPEED REGULATING 0R C'ONTROLLING DEVICE FOB ELEVATURS.

(Application led Feb. 20, 1899.)

UNITED STATES Price.

ArtNr EDWARD P. FORBES, OF HARTFORD, CONNECTICUT.

SPECIFICATION forming part of Letters Patent No. 635,679, dated October 24, 1899.

Application tiled February 20, 1899. Serial No. 706,096. (No model.)

To @ZZ whom it may concern:

Be it known that I, EDWARD P. FORBES, 'a citizen of the United States, residing in Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Speed Regulating or Controlling Devices for Elevators, of which the following is a specification.

This invention relates to means for regulating the speed and for controlling the movement of elevators, and has for its object to provide devices of the class mentioned whereby the speed of the elevator may be automatically controlled, and also has for its object the automatic release of the speed-controlling devices in case the hoisting-rope should break or when from other causes the descent of the elevator is beyond the control of the attendant.

In the accompanying drawings, Figure l represents a side view of the elevator and the controlling apparatus in its normal condition. Fig. 2 represents a partial front view of the same. Fig. 3 is a view corresponding to Fig. l, showing the hoisting-rope broken and the controlling device in full operation; and Fig. 4 represents a detail to be more fully described hereinafter.

Similar characters designate like parts in all the figures of the drawings.

In the accompanying drawings, C represents the elevator-car; R, the hoisting-rope; r, the rope attached to the counterweight, and l0 what I preferably term the speedcontrolling rope, which, however, in this case is entirely independent of either of the two ropes previously mentioned, but moves in unison therewith and is for thisreason attached to the cross-bar 1l at the top of the car C.

Located within or near the elevator-shaft is the tube or cylinder 12, the inside of which is smooth and is adapted to receive the piston P, provided with two heads 13 and 14, the former of which is directly connected with the cross-bar 11 by means of a rope 10, while the rope 15, passing under the sheave 16, connects the head 14 of said piston P with the under side of the car C. Hence it will be understood that the piston P is directly operated from the car C, but acts in opposition to the movement of the same. In other words, when the car is ascending the piston is descending within its tube, and the reverse is true during the downward movement of said car.

The tube or cylinder l2 is rmly held in place by the bracket 17 at the top of said tube and by a bracket I8 at the bottom thereof and carries at its upper end a sleeve 20, held in sliding contact thereon and preferably provided with a screw-thread 21, said sleeve being adapted when released to slide downward on said tube l2 and to then cover a series of openings 22 at the upper end of said tube when it is arrested in its downward movement by the projecting ring 23 on said tube 12. The sleeve 2O is supported in its normal position bya detent or hook lever 24, which is pivoted at 25 to the bracket 1'7 and the lower end 24a of which engages the screwthread. 2l, the object of which is to provide means for adjusting the sleeve 2O vertically, so as to regulate the size of the openings 22 to any desired degree when in normal condition. The lever 24 has an extension 24b beyond the pivot-point 25, which extension is adapted to be operated to withdraw the hook 24 from the sleeve 2O when the speed of the descending elevator is beyond a predetermined limit or in case of accident-as, for instance, if the hoisting-rope should break-in which condition the ear will of course be beyond the control of the operator. The rope l0 is carried over a pulley 30 and is connected to the upper head 13 of the piston P, and it will therefore be seen that when the car C descends the pulley 30 will be rotated or driven by the rope l0. At one side of said pulley I have provided a series of pawls 3l, each of which is pivoted thereto, as at 32, and has an extension 33, between which and the hub of the wheel a spring 34 is placed, tending to throw the latch 3l toward the center of the pulley-shaft 35, and the springs 34 are so adjustedthat when the circumferential speed. of the pulley 30 exceeds a certain limit the pawls 3l will be centrifugally thrown outward against the stress of said springs into such position that they will strike the extension 24b of the hook-lever 24, and thus cause the release of the sleeve 20, which latter will immediately drop and close the openings 22, thereby sealing the upper end of said tube 12, so that as the car C descends the air con- IOO tained in said tube between the piston-head 13 and the now-sealed upper end thereot will be compressed to form a cushion, the ettectiveness of which increases with the descent of the car and the consequent ascent of the piston. At the lower end of the tube 12 I provide a similar sleeve 40, having a screwthread 41 and adapted to close the openings 42 in the lower end of the cylinder 12. Another hook-lever 43 is pivoted at 44 to the tube 12, and the hook 43 thereof is adapted to engage the screw-thread 41, whereby the openings 42 may in their normal or open condition be covered to anydesired extent. The lever`43 is provided with the ear 43", which is connected, by means of a rod, cord, or other device 45, to the ear 24C of the lever 24 above mentioned, so as to cause both

levers

24 and 43 to be operated simultaneously for releasing their respective sleeves 40 and 20. It will therefore be evident that when the sleeve 40 has closed the openings 42 in the tube or cylinder 12 and the car descends a partial vacuum will be formed in the lower end of said tube between the piston-head 14 and the bracket 18, the effect of such vacuum increasing with the descent of the car.

In order to close the ends of the cylinder 12 at the points where the

ropes

10 and 15 are passing through the heads or brackets 17 and 18, I preferably employ at these points the construction shown in Fig. 4, in which the cylinder 12 is represented as having a screw-thread 12L engaging a corresponding screw-thread 17u on the bracket 17, so that the cylinder andthe brackets 17 and 1S form, practically, one solid structure, and at the point where the ropes are passing through said heads I prefer to employ a bushing B, having the head b at one end and a nut n at the other end thereof, which bushing is provided with an opening to receive the rope 10 in a running but not loose fit, while the body of the bushing B is somewhat smaller than the openingin the bracket 17, so thatsaid bushing may adapt itself to the sway of the rope 10, and thereby prevent the latter from wearing' an enlargement in the head, which would naturally leave an opening for the air to escape. The rope 15 passes through a similar bushing B', which prevents any undue leakage of air at the'lower end of the cylinder.

As the primary object of thesleeves 2O and 40 is to provide means whereby the passage of air into or out ot the cylinder l2 may be regulated, it is obvious that the smaller the openings 22 42 the more difficult will be the movement of the piston P. In other words, in this condition the cylinder 12 performs the function of a dash-pot, which permits the piston to move only at a predetermined speed, such speed being dependent upon the facility with which the air can be forced out from one end and drawn into the other end of said cylind er. A secondary object of the sleeves 2O and 40 is to provide means whereby the ends of the cylinder 12 may be entirely closed to prevent the passage of air either in or out of said cylinder at the time when the car is beyond the control of the operator, so that an absolute air-cushion is formed at one end, while at the lower end the suction-openings are closed, and a vacuum will naturally result by the upward movement of the piston I.

YVhen the car is beyond the control of the attendant, as above mentioned, I deem it a matter of great importance that the power of the driving mechanism should be instantly shut ott or disconnected, and I therefore provide means whereby such power is automatically disconnected from said driving mechanism at the moment when the sleeves 2O and 40 are released, as above described.

` In the accompanying drawings I have illustrated a switch S, through which when arranged as shown in Fig. 1 an electric current will pass to the motor for driving the hoisting mechanism, and the switch-leverlis connected, by means of the pitman l', to the end of the hook-lever 43, so thatwhen said hooklever 43 is thrown out of engagement with the sleeve 40 the switch-arm Z is thrown into the position shown in Fig. 3 and will consequen tly break the current at that point, leaving the motor disconnected. Instead of being connected to the switch-lever Z the rod Z may be attached to a belt-shipper or to the stem o't` a valve of Whatever system may be used for operating the elevator.

It is to benoted that the tube or cylinder 12 constitutes an air-chamber and that it is immaterial how such chamber may be formed. So, too, the sleeves 2O and 40 constitute valves for regulating the ent-rance of air to and its exit from the chamber, and, as is obvious, the form of these valves may be varied within wide limits without departing from my invention. Furthermore, said valves need not necessarily be externally threaded, as illustrated and described, as other provisions could readily be adopted for engaging the latches or hook-

levers

24 and 43. Many of the details of the mechanism described could also be modified and still be within the purview of the invention.

The elevator m ay be of any well-known type and may be operated by any-motor common to the art.

Having described my invention, I claim- 1. The combination, with an elevator, of an air-cham ber adjacent thereto; a piston in said airchamber connected at different points to the elevator-car; and automatic means, governed by the movement of the car, for regulating the passage of air into and from said air-chamber.

2. The combination, with an elevator, of an air-chamber adjacent thereto and provided with passages to permit the entrance and exit of air, of a piston in said air-chamber connected at different points with the elevatorcar; and means, governed by the movement of the car, for controlling the action of said piston.

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3. The combination, with an elevator, of a cylinder adjacent thereto, said cylinder having air entrance and exit openin gs at its ends; a piston mounted within said cylinder and connected at each respective end with the elevator-car; valves for controlling the size of the air entrance and exit openings; and means, governed by the movement of the car, for automatically releasing said valves should the elevator exceed a predetermined speed.

4. In combination with an elevator, an airchamber having air exit and entrance openings at its ends; valves for governing the entrance of air into, and its exit from, said openings; means for holding said valves in their desired positions; and means, governed by the movement of the elevator-car, for automatically releasing said valves.

5. The combination, with an elevator, of an air-chamber adjacent thereto provided with air entrance and exit openings; sleeve-valves for regulating the size of said openings; means for holding said valves in their desired positions; means for releasing said valves; and means within the air-chamber for controlling the movement of the elevator-car.

6. The combination, with an elevator, of an air-chamber adjacent thereto; a piston 4connected with the elevator and freely movable in said air-chamber; valves for regulating the supply of air to, and its exit from, said airchamber,said valves being provided with projections; latches for engaging said projections and holding the valves in their desired positions; and means, governed by the movement of the car, for tripping said latches.

7. In combination with an elevator, a cylindrical tube having air-passages at its upper and lower ends; externally-threaded sleevevalves for regulating the size of said passages; a piston within said tube connected at both ends with the elevator-car; pulleys over which the connections pass; and a centrifugal device, carried by one of the pulleys, for releasing the latches holding the sleeve-valves.

8. In an elevator, the combination,with an elevator-car, of a cylindrical tube having airpassagcs at its upper and lower ends; externallythreaded sleeve -valves for governing the size of said passages; a double-headed piston Within said tubes; connections passing from the upper and lower heads orn said piston, respectively, to the upper and lower ends of the elevator-car; latches for holding the sleeve-valves in their desired positions; a connection between said latches; and a series of centrifugally-operated devices, controlled by the mechanism of the car, for tripping one of said latches.

9. In combination,with an elevator, an airchamber adjacent thereto and provided with air entrance and outlet openings; adjustable valves for controlling said openings; means for holding said valves in their adj usted positions; a piston within the air-chamber, said piston being connected to the car; and means, operated by the car when it exceeds a predetermined limit of speed, for releasing said valves.

l0. The combination,with an elevator, of an air-chamber adjacent thereto `provided with air inlet and exit openings; a piston within the air-chamber; connections from said piston to the car; valves for controlling the entrance of air to, and its ex'it from, said openings; means for holding said valves in their desired positions; means, governed by the car when it exceeds a predetermined limit of speed, for releasing said valves; and means for shutting oft' the power for driving the elevator when said valves are released.

ll. The combination,with an elevator, of an air-chamber adjacent thereto provided with air inlet and outlet openings; a piston in said air-chamber connected to the car adjustable valves for regulating the size of said openings; means for holding said valves in their adj usted positions; means, governed by the speed of the elevator,for releasing said valves and aconnection from one of said means to the source of power. f

12. The combin ation ,with an elevator,oiI an air-chamber adjacent thereto, said chamber being provided with air inlet and exit openings at its lower and upper ends, respectively; adjustable valves for controlling the size of said openings; means for holding said valves in their adjusted positions; a piston within the air-chamber, said piston being connected at each end with the elevator-car; and means for releasing the valves, one of said means involving a device for shutting off the power. 13. The combination, with an elevator, of a cylindrical air-chamber contiguous thereto and provided `with air inlet and outlet openings at its ends; valves for controlling the size of said openings; a piston within the air-chamber and connected by ropes with each end of the elevator; pulleys over which said ropes pass; and a device, carried by the tube, for permitting slight movement of one of the ropes, to prevent leakage of air or the enlargement of the space within which the rope opcrates.

. EDWARD P. FORBES. Witnesses:

WM. I-I. BLODGETT, HENRY BrssnLL.

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