US1422774A - Safety device for elevators - Google Patents

Description

Patented July 11, 1922.

2 SHEETS-SHEET I.

INVENTOI? Haeey/Va G/AL/VEQ)" A TTORNEYS H. McGlLLlVR'AY.

SAFETY DEVICE FOR ELEVATORS.

' APPLICATION FILED MAR- 22, 1921.

1,422,774, Patented July 11, 1922,

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WITNESSES IN VE N TOR ATTORNEYS UNITED STATES,

PATENT OFFICE.

SAFETY nnvrcn FOR ELEVATORS.

Application filed. March 22, 1921.

the cables by which the same are supported- Another object in view is to provide in connection with a means for automatically stopping and locking an elevator in event of the breaking of the cable, a means for simultaneously cutting off power for driving the same.

A still further object in view resides in the provision of a safety device for elevators which includes pivoted levers having cammed extremities normally retained out of engagement with the guide rails of the shaft by supporting cables for the elevator which cables are connected with the pivoted levers. I

A further object of the invention resides in the provision of a safety device includ ing pivoted levers, the cammed extremities of which are provided with guide flanges which function to maintain said extremities in juxtaposition at all times.

A still further object in view resides in the provision of a safety device including pivoted levers with cammed extremities which are adapted to be thrown to active position by means of springs in which means is provided for relieving the springs of wear when the levers are normally retained in in active position.

Another object is the provision of a safety device of the character described which is simple in cgnstruction,inexpensive to manufacture and install and which is thoroughly reliable and highly efficient in its purpose.

With the above recited and other objects in view, the invention resides in the novel construction, combination and arrangement of parts set forth in the following specification, pointed out in the appended claims and illustrated in the accompanying drawings, in which;

Specificationof Letters Patent.

PatentedJuly 11, 1922.

Serial No. 454,330.

Figure 1 is a fragmentary front eleva tlon of an elevator and a counterweight therefor equipped with a safety device con.

, tuting a part of the invention.

Figure 3 is a fragmentary enlarged front elevation of the upper portion of the car, parts being "broken away to disclose the underlying structure and illustrating in. dotted and full lines normal and actuated position of the parts. f

Figure 4 is a horizontal plan view taken approximately on the line l 1 of Figure 3.

Figure 5 is a vertical transverse sectional view taken approximately 011 the line 5-5 of Figure 3.

Figure 6is a similar sectional view taken approximately on the line 66 of Figure 3.

Figure 7 is an enlarged fragmentary elevation of the counterweight attachment, parts being shown in section. v

Figure 8 is a horizontal sectional view therethrough taken approximately on the line 8-8 of Figure 7.

Referring to the drawings by characters of reference, 10 designates an elevator shaft provided with vertical T-shapecl guide rails 11-11 disposed centrally at the opposite sides thereof over which the car 12 is guided. The car is provided with the usual super structure which includes the transverse channel iron beams 13-13. The shaft and car may be of any approved type now in general use, the showing made in the drawing being merely illustrative of one form to which the safety attachment may be applied. The safety 7 attachment comprises a pair of levers 1414 each of which is pivoted adjacent its "outer end as at 15 underneath the outer ends of the beams 13. The outer extremities of the levers 14 are enlarged as at 1 6 and said enlarged extremities are provided with cammed outer end walls 17 I which are designed to be disposed out of contact with the rails 11 when the inner extremities of the levers 14 are swung upwardly. The inner extremities of the levers are apertured as at 18 for the reception of the vertical bolts 19 The upper endsof the bolts 19 are provided with bifurcated heads '20 in jwhich a're received the looped terminals 21 of the su portin cables 22. The cables 22 are trained 7 over t, e "guide pulleys 23 arranged at this top of the shaft and the opposite loop terminals 24 of said cables are connected to the counterweight 25 in a manner to be hereinafter set forth. A plate 26 is bolted or otherwise secured to the under side of the channel beams 13 to straddle the same and said plate is provided with spaced apertures 27 through which the bolts 19 extend. A hearing sleeve 28 is arranged over each bolt 19 and is disposed between the inner end of the lever and the under side of the plates 26. The lower end of each bolt 19 has mounted thereon a ball race 29 in which the antifriction balls 30 and retained. A pair of lock nuts 31 are threaded on the lower end of the bolt to retain the ball race 29 thereon. A washer 32 is secured to the under side of the inner end of each lever 14 with its central aperture in alignment with the aperture 18. A coiled contractile spring 33 surrounds each sleeve 28 and bolt 19, the opposite ends thereof respectively bearing on the plate 26 and the upper side of the inner end of the levers 14. The counter weight 25 is provided with a pair of levers 34 each of which are pivoted as at extremities 35 adjacent their enlarged outer extremities 36 to the under side of the transverse beam 37 of the superstructure. The outer end of the levers 34 are cammed as at 38 and are adapted to normally be disposed out of engagement with the guide rails 39 for the counter weight when the inner extremities of the levers 34 are swung upwardly. The locked terminals 24 of the supporting cables 22 are connected to the inner arms of the levers 34 by the bolts 40. A coiled contractile spring 41 is interposed between a plate 42 secured to the beam 37 and a plate 43 secured to the upper side ot the extreme inner end of the levers 34. A suitable spacing sleeve 44 is carried by the plate 42 and is arranged within the convolutions of the springs 41 for the purpose of supporting the inner end of the lever 34 prior to the complete compression of the springs 42. The outer enlarged extremities of the levers l4 and 34 are each provided with flanges 45 which extend outwardly from. the ends and embrace the guide rails 11 and 39 respectively for maintaining the cammed outer end walls in juxtaposition thereto.

The circuit wire 50 which leads from the source of supply to the controller handle 51 is arranged to traverse the beam 13. The circuit wire 50 is broken at two points 52 and 53 and is provided with spaced terminals 54 and 55 adjacent each of said gaps. A bridge element 56 is provided for each gap or brake 52 and 53. The bridge elements 56 are respectively mounted on a vertically movable rod 58 mounted in suitable guides on the beam 13. The lower extremity of each rod 58 is provided with a roller 59 which co-acts with the upper surface of the lever 14. By this arrangement when the levers 14 are swung upwardly to normal position, the bridge element 56 will bridge the gaps and establish communication between the contact terminals 54 and 55.

In operation of the device the supporting cables 22 normally support the weight of the car 12 and the counter weight 25 through the bolts 19 and 40 respectively. The upward pull on said bolts will ellect contact of the sleeves 28 with the plates 26, the contact of the ball race with the washer and the contact of the inner end of the levers 14 with the sleeves thereby compressing the springs 33. At the same time the inner end of the levers 34 ot the counter weight will be hcl d in contact with the spacer sleeves 44. The length of the sleeves 28 and being sillficient to prevent the entire compression ol? the springs 33 and 41. The anti-it'rictiou balls 30 will permit the bolts 19 to rotate whereby to relieve the cable of any kinks or twist which may occur therein.

In this position the outer cammed extremities or walls 17 and 38 of the levers 14 and 34 will be maintained out of contact with the guide rails 11 and 39. In event of the breaking of all of the supporting cables 22, the springs 33 and 41. will be instantly released to effect a downward movement of the inner ends of the levers 14, and 34 respectively the rods 58 will gravitate to break the circuit wire 50 by opening the gaps 52 and upon movement of the bridge elements 56 out or contact with the terminal contacts 54 and This will automatically cut oii? the power. Tn event of the breaking of one of the cables only, the downward movement of one of the levers 14 will break the circuit wire 50 to cut of? the power without jamming the car so that repairs can be made before the other cable is severed.

lVhile there has been illustrated and described a preferred embodiment of the invention. no limitation is necessarily made to the precise structural details therein exhibited as it is to be understood that variations and modifications that properly fall within the scope of. the appended claims may be resorted to when found expedient.

I claim:

l. The combination with an elevator shaft having vertical guide rails, a car a plurality of supportingcables therefor, independent means carried by the car and attached to each supporting cable adapted to coact with the guide rails for i rictionally locking the car within the shaft upon breaking of the supporting cables and a circuit adapted when closed to operate the car, of circuit breakers normally held in circuit closing relation by the levers for completing the circuit and operable by movement of said levers upon breaking of any of the cables to open the circuit for stopping the car.

2. In a safety device for elevators, the combination with an elevator car and counterweight therefor movable between vertical guide rails, of means for frictionally locking the car and the counterweight withln the shaft comprising a pair of levers carried respectively by the car and the counterweight, each of said levers including a cammed head, means for rocking the levers to effect frictional engagement of the same with the guide rails, and a pair of cables constituting a connection between each car lever and counterweight lever for holding the levers normally in an inactive position to retain the cams out of engagement with the guide rails, in combination with a circuit serving when closed to operate the car and including an operating controller switch, a pair of circuit breakers, each normally held in circuit closing relation by one of the car levers and operable upon breaking of the cables to open the circuit for stopping the car.

8. In a safety device for elevators, the combination with an elevator car and counterweights therefor movable between vertical guide rails in the elevator shaft, of means for frictionally locking the car and counterweights within the shaft in event of breaking of the cables, comprising levers pivoted respectively to the car and counter weight, each of said levers including cammed heads, a spring adapted to coact therewith for rocking the lever to a position to effect frictional engagement of the cammed head with the guide rail, a cable connection between each set of car and counterweight levers for holding the levers normally inactive to retain the cammed heads out of engagement with the guide rails, and means interposed between the lever and the car or eounterweight structure constituting the abutments for limiting the compression of the springs whereby the carrying load is carried by said means.

at. In a safety device for elevators, the combination with an elevator car and counterweights therefor movable between vertical guide rails in the elevator shaft, of means for frictionally locking the car and counterweights within the shaft upon breaking of the cables, comprising a plurality of levers pivoted respectively to the car and counterweights, a cammed head on each of said levers having side flanges projecting outwardly therefrom to retain the same in juxtaposition to the guide rail, a spring adapted to coact therewith for rocking the lever to effect frictional engagement of the same with the guide'rail, cables respectively attached at their opposite ends to one of the levers of the car and one of the levers of the counterweight for connectiong the same and for holding the levers normally inactive to retain the cammed heads out of engagement with the guide rails, and means coacting with each lever of the car for throwing off the power to bring the car to a stop in event of breaking of its cable.

5. In a safety device for elevators, the combination with an elevator car and counterweights therefor movable between vertical guide rails in the elevator shaft, of means for frictionally locking the car and counterweights within the shaft upon breaking of the cables, comprising a plurality of levers pivoted respectively to the car and counterweights, a cammed head on each of said levers having side flanges projecting outwardly therefrom to retain the same in juxtaposition to the guide rail, a spring adapted to coact therewith for rocking the lever to effect frictional engagement of the same with the guide rail, cables respectively attached at their opposite ends to one of the levers of the car and one of the levers of the counterweight for connecting the same and for holding the levers normally inactive to retain the cammed heads out of engagement with the guide rails, and means coacting with each lever of the car for throwing off the power to bring the car to a stop in event of breaking of its cable, said means comprising in the operating circuit of the car a plurality of gaps corresponding to the number of levers,

a movable rod having a bridge member carried thereby, said rod having engagement with the lever for normally holding the bridge member carried thereby, said rod having engagement with the lever for normally holding the bridge member in bridging relation to the gap when the lever is 1n normal position.

HARRY MGGILLIVRAY.

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