US1148257A - Elevator safety device. - Google Patents

Description

A. C. SMITH.

ELEVATOR SAFETY DEVICE.

APPLlCATlON man SEPT. 15. 1911.

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ELEVATOR SAFETY DEVICE.

APPLICATION FILED SEPT. 15. 1911.

Patented July 27, 1915.

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A. C. SMITH.

ELEVATOR SAFETY DEVICE. APPLICATION n'uzu SEPT. 15. 191 i.

Patented July 27, 1915.

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A. 0. SMITH,

ELEVATOR SAFETY DEVICE.

APPLICATION FILED SEPT. l5. l9! 1.

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PATENT OFFTFE.

ALLEN C. SMITH, 0F YOINKERS, NEW YORK, ASSIGNOR T0 OTIS ELEVATOR COMPANY, OF JERSEY CI'IY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELEVATOR SAFETY DEVICE.

Application filed September 15, 1911.

To all whom it may concern Be it known that I, ALLEN O. SMrri-I, a citizen of the United States, residing at Yonkers, in the county of Westchester and State of New York, have invented a new and useful Improvement in Elevator Safety Devices, of which the following is a specification.

My invention relates to safety devices for elevators and more particularly to such safety devices as have jaws located on the car and which are adapted to grip the guide rails when the car travels at an excessive rate of speed or when it is desired for any purpose to apply the safety device.

One of the objects of my invention is the provision of means for effecting the simultaneous operation of the gripping jaws to engage the guide rail when the car travels at an excessive rate of speed or when it is desired for any reason to apply the jaws to the rail.

Another object is to facilitate the application and removal of the safety device from the car when the latter is in the hatchway.

A further object of my invention is the provision of means which are simple in construction, easily installed and free from lost motion.

It has been found in practice that in safety devices of this type there are several imperfect features. One of these features is the tilting of the elevator car caused by the failure of the gripping jaws to grip the guide rails with equal pressure on both sides of the car. This unequal pressure of the gripping jaws is due to the failure of the jaws to operate simultaneously, as by lost motion, for instance, in several of the parts, or any way, to the failure of the jaws to operate simultaneously to engage the guide rails, but in my device I overcome'this' objectionable feature by providing an arrangement in which there is no lost motion; and which effects the simultaneous operation of the jaws to engage the guide rails.

On installing and repairing a safety device of this type, it has been found necessary on account of lack of space in the hatchway to out holes in the sides of the hatchway in order to install or remove broken parts, such as in a case where a rod or shaft is used to connect the two sets of gripping jaws, but in my device I overcome the above men- Specification of Letters Patent.

'rod f. When the car O Patented July 27, 1915. Serial No. 649,519.

tioned objectionable features by a compact arrangement of parts which areeasily i11- stalled and replaced and are also free from lost motion.

Referring to the drawings, Figure 1 diagrammatically illustrates the application of my device in an elevator system. Fig. 2 is a side elevational view of the gripping jaws and a safety plank. Fig.v 3 is a part sectional plan view of Fig. 2. Fig. 4; is a side elevation showing a portion of the top of an elevator car with a device attached thereto which is connected to a governor rope to operate the gripping jaws. Fig. 5 is a plan view of Fig. 1. Fig. 6 is an elevational view of one of the segmental gears, taken on the line 8, s, Fig. 3, looking in the direction of the arrows.

In describing. my device it will be neces sary only to describe the parts on one side of the car, since the parts are the same on both sides, with the exception hereinafter noted- Referring now to Fig. 1, a motor, M, is

directly connected by means of a shaft 1 to a hoisting apparatus P, which is connected to a car O and counterweight W by means of a cable 3, passing over sheaves, 4, 5 and 6, mounted on a beam N. A brake R of a well known type is shown. The governor-rope 7, is adapted to run with the car O, and has both of its ends secured to a double-eye rope-fastener 8 which is secured to a lever 9. The governor rope runs up and over a sheave 10 which is preferably situated above the upper limit of the cars travel, thence down and under a sheave 11 near the lower limit of the cars travel. The sheave 11 may be provided with weights 12 which will serve the purpose of keeping the governor rope 7 at a proper tension. A speed governor K of a well known type is shown, having jaws, e, operated through a attains a'predetermined speed the governor rope operates its jaws, 6, through the rod 7, to'grip the rope 7, thereby causing the safety device to operate. A further description of the latter will be given later.

Referring now to Figs. 2 and 3, a portion of two channel beams, A, is shown, which forms a part of the framework of the car O. A safety block 13 is secured to the bottom of each beam by bolts 14:, 14, and consists of a respective shafts 19 in the journal bearings E by the pins 20. The gripping jaws are provided with teeth 18 which insures a suitable gripping effect of the jaws to the guide rails G. The shaft 19 extends through the'bearing E and into a hub 22 of a segmental gear 21, the latter being secured to the shaft 19 by a pin 23. A shaft 19 extends through a bearing E and supports a jaw on one end and a segment gear 21 on theiother end, secured thereto by a rivet 2f, the two gears 21 and 21 intermeshing with each other. The gear 21, Fig. 6, has a hub 22 which is socketed or recessed as at 25, to receive the end of a cross-bar 26. The recess and end-of the bar are angular in corresponding crosssection to each other and the end of the bar snugly fits the recess. The wall of the hub is split or has an entry to the recess 25, the end of-the bar to be transversely entered therethrough to reach the recess. Thereare bolts 27 to retain the end of the bar orlshaft in the recess. It is plain that the recess and the end of the bar might beround, and a set screw be used to effect an engagement between the two parts to hold the bar from turning in the recess; or some other kind of coupling be used. The bar 26 connects the segmental gears 21 and the shafts of two of the jaws, one jaw on each side, of the car. The bar secures and insures the simultaneous movement of the two jaws,

and through the intermeshing gears, the simultaneous movement of all the jaws. This arrangement secures an equal pressure of the jaws, and oneach side of the car, and thereby provides against the car being tilted upon being arrested in its motion by the safety device, .since the jaws move together to grip the guides. I have divided the shaft, which usually extends across the car and supports the jaws, into three parts, and joined them together at their ends by means of the coupling socket or recess. This division enables me to withdraw the bar transversely of its length instead of endwise, and thereby avoids the necessity of cutting a hole in the side of the hatchway through which to permit the endwise withdrawal of the bar and the corresponding removal of the jaws and gears, and other parts of the safety device. This feature is of signal advantage and will be readily appreciated, since heretofore with an integral or one-piece bar, great difliculty and expense have been incurred to get at the parts to remove and replace worn or broken parts.

A red 28 is pivotally connected to one gripping jaw 18 by a bolt 17, and this red extends upwardly and is suitably secured to a lever 9 of the interlocking device 1*]. In the diagrammatic representation of the device shown in Fig. 1, the rod 28 is pivoted to the lever 9 at a point somewhat removed from the end of the lever merely for the sake of clearness of illustration. 1n the actual construction of the device, I prefer to pivot the rod 28 as shown in Figs. 4 and 5, in which the rod lies in a slot 30 in the lever 9 and is provided with a convex washer and nut as shown, so as to prevent cramping of the red when the lever 9 is swung upon its pivot. The interlocking device is mounted on the channel-beam J at the top of the car C. The interlocking device H consists of a lever 9 pivotally supported on a stud 31 which extends through the channel beams J. The slot 30 is to allow a free movement of the rod 28, when the lever 9 is moved. The double eye rope fastener S is secured on the lever 9 by the bolt 32 and has the two ends of the governor rope 7 secured thereto. A bracket 33 is secured to the beam J by bolts 34, and is formed with lugs through which extends a pivot rod 37. Mounted on the rod 37 is a detent lever 36, the upper end of which is formed with a rounded knob or detent adapted to engage a corresponding recess 39 formed in the lever 9. The detent lever is held in engagement with the lever 9 by means of a coil spring 38 mounted on a rod 38 having a screw-threaded connection with the bracket 33. The spring 38 bears at its opposite ends against the detent lever and a washer 29' on the rod 38. The detent 36 holds the lever 9 in its normal position with a yielding pressure and prevents said lever from being operated by any slight pull on the governor cable 7, but will relieve or release said lever when the cable is gripped by the governor K.

I will now describe the operation of my device :Under usual conditions the elevator car C will run up and down over the guides G and in doing so will carry the governor rope 7 with it. This will cause the speed governor K to be rotated at a speed proportional to that of the car. If for any reason the speed of the car in its downward travel becomes excessive, the speed governor K will then raise the governor rod 7" to such a degree as to cause the clamping jaws'e to be quickly and powerfully drawn against the governor rope 7. This will arrest the movement of the governor rope and will cause it to pull the lever 9 upwardly, the pull on the rope 7 overcoming the action of theinterlocking spring-pressed detent 36 which normally locks the lever 9, thereby holding the safety-device on the bottom of the car C in its normal position. The rod 28 which directly connects the lever 9 and the gripping jaw 18, will be pulled upwardly with the lever 9, thereby causing the two sets of gripping jaws simultaneously to engage with the guide rails G to arrest the movement of the car C. It will be seen that the initial upward pull on the rod 28 is sulficient to bring the teeth on both sets of gripping jaws into engagement with the guide rails. The downward movement of the car will cause the gripping jaws to be further rotated, thereby causing the gripping teeth to engage deeper into the guide rails thereby giving a powerful gripping effect. A great strain is brought to bear upon the shafts which support the gripping jaws and also the connecting shaft or bar 26, when the grip dogs are in operation, but to overcome this I provide stops 40 on both safety blocks which limit the upward movement of the gripping jaws and relieve the strain from their connecting parts.

It will be seen with my device it will be impossible to get an unequal application or pressure of both sets of the gripping jaws to the guide rails, which would tend to tilt the car, because as soon as the rod 28 is pulled it imparts the same motion through the shaft 26 to the set of gripping jaws on the other side of the car, the meshing segmental gears assuring the simultaneous operation of the gripping jaws to engage the guide rails with a quick and equal pressure.

In Fig. 1 I have shown an arrangement whereby the safety device may be operated manually from the car if for any reason it may be found necessary. For this purpose a rope 4:1 is secured to the end 42 of the lever 9, and is adapted to be pulled downwardly by hand, thereby releasing the lever 9 from engagement with the interlocking detent 36. The upward movement of the opposite end of the lever 9 causes the safety device to operate the gripping jaws in the manner as has been described heretofore.

lVhile I have disclosed in detail the various parts, I wish not to be confined to the details disclosed, but to have the benefit of all equivalents to which I may be entitled.

Having thus described my invention,

Copies 01' this patent may be obtained for five cents each, by addressing the what I claim and desire to secure by Letters Patent is 1. In an elevator or hoisting apparatus, a safety device comprising sets of pivotally supported gripping jaws, intermeshing gears for each set, one of the gears of each set having a socket or recess angular in cross-section and split to allow the entry to the socket of a bar, a bar having an end angular in cross-section to correspond to the cross-section of the socket, the locking means to hold the jaws in an inoperated position, means connecting the jaws and the locking means, and means for releasing the locking means to efiect the simultaneous operation of the jaws to engage the rails, substantially as described.

2. A safety device for a hoisting apparatus, comprising a jaw, a socket or recess part secured to the jaw, a jaw bar, the socket having an entry through its wall, adapted to allow the end of the jaw bar to be passed therethrough into the socket or recess.

3. A safety device for a hoisting apparatus, comprising a jaw, a socket or recess part secured to the jaw, the socket being angular in cross-section and having an entry or split through its wall, a jaw bar having its end angular in cross section to correspond to the cross section of the said socket, to allow the end of the jaw bar to be seated into the socket or recess.

4. A safety device for hoisting apparatus, comprising two simultaneously operable oppositely opposing jaws on either side of the car, intermeshing gears for each set, one of the gears of each set having a socket or recess angular in cross section and split to allow the entry to the socket of a bar, and a bar having ends angular in cross-section to correspond to the cross section of the socket.

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

ALLEN 0. SMITH.

Witnesses:

F. O. DU'r'roN, GEORGE D. Rosn.

Commissioner of Patents,

Washington, D. G.

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