US1458791A - Safety apparatus for elevators - Google Patents

Description

June 12,1923.

- 1,458,791 P. J. WOOLDRIDGE SAFETY APPARATUS FOR ELEVATORS Original Filed June 13, 1919 2 Sheets-Sheet 1 June 12, 1923.

P. J. WOOLDRIDGE SAFETY APPARATUS FOR ELEVATORS 1919 2 Sheets-Sheet 2 Original File June 13,

Patented June 12, 1923.

oat-tran ar ES- Y rear/n SAFETY APPARATUS EoE- ELEVATORS.

Application filed June 13,1919, serial mleoaseo. Renewed November 1, 1922. Serial no 598,43f

To all whom 2'2? may concern:

'Be it known that I, POWHATAN J, WooL- BRIDGE, a citizen of the United States, residing in Pewee Valley, Oldham County, Kentucky, have invented certain new and useful Improvements in Safety Apparatus for Elevators, fully described and represented in the followin specification and the accompanying drawings, forming a part of the same. The general objects ofthe invention areto discontinue propulsion of the car when a shaft door is opened with the car near a landing, or if the motive power has already been out off when the door is opened, toprevent starting the car in either directionuntil the door is closed; .to' make the means for shutting off power operative whether or not the car oscillates within reasonable limits as it is being stopped; and to prevent opening the door except when the caris close to the landing. v

A special object is to arrange. parts of the mechanism located in the shaft within very narrow limits in a direction perpendicular to the shaft wall.

Another particular object is to arrange the parts of the mechanism-which are located both on the shaft and on the car so that none of them extend at all into the clearance space between the car and the shaft unless the shaft door is opened Another object is to prevent improper contact between parts, of the mechanism carried by the shaft walhand the car'or parts carried on the car. I

A further object is to simplify and improve the construction and operation of devices of this character in wayspointed out hereinafter.

The accompanying drawings show one exemplifying embodiment of the invention. After considering this, personsskilled in the art will understand how the invention may be embodied in other-forms without departing from theseprinciples, and' l do not limit myself to details except as claimed. Fig. 1 is a horizontal section through the shaft wall showing in plan a structure embodying my invention, fragments only of the shaft wall and-car being shown.

Fig. 2 is an elevationof parts of 'th structure carried by the shaft wall looking outward from a position above the car, an upper corner of one of the shaft doors being shown, and of safety mechanism carried by the car in correct relation to theshaft parts,

the car, however, being entirely'omitted for car, showing the safety mechanism inside 1 elevation. v V s Fig. 4 is a View similar to Fig. 1, showing the parts in one active position. ,1 i ig. 5 is an enlarged fragmentary detail of the safety door latch or check device. 1

Fig. 6'is an elevation'o'fair'elevator car equipped in accordance with my invention.

S is the shaft wall, D a horizontally slid- .ing shaft door, and C the upper structure of a car.

t'he Shaft Wall, r yabove the" door, is fixed a flat'frame member'f l having a lower horizontal extension'2provided with a guide slot "consisting ofahoriz ontalportion 3 and an'end portion' i isinthe form of a'substantially semi-circular curve.

The lower end of frame 1 is spaced slightly away from the wall a block 5, and the upper end is similarly spaced from-thewall by horizontal strip '6 which liesa'gainst'ithe wall. Across-piece 7 secured to stripGcarries hinge pins 8 on which ispivoted one end of the swinging safety "or stop arm 9. At

an intermediate point on frame memberl'is secured a fulcrum stud 10 having an enlarged head ll. The stop armoperatinglever 12 has a slot13 embracing the-fulcrum stud'on which the lever may move'pivotally and also vertically and horizontally to .limited extent. The lower end of operating lever 12 is secured to a stud 1r on which is pivoted the hub of a cam 15 which has'two arms 16 and 17 On the topof the doo'ris secured a cam operating arm 60. The end shaft wall and engages in slot3. The hub of cam 15'also has an inwardly extending Stud 18 engaging. in slot 3. The lower end of operating lever 12 is urged'to inactive or wardly and then bent again so that-the u p- I V of stud 14 is extended inwardly toward the H per and lower end portions of the lever are parallel to the. middle portion, but lie normally farther outward from the shaft wall." At the upper end of the lever is formed a cylindrical portion 25 which passes through a hole 26 in safety arm 9 This hole is slightly larger than cylindrical member sufliciently to permit said member to occupy different angular positions in the hole, one of these positions being shown in Fig. 2. Arm 9 terminates in an end portion 28 of reduced, size which serves to directly actuate a circuit breaker rail carried on the car.

011 the car, usually above, the roof and secured to structural parts of the car is a frame 30, 31, 32, 33. Vertical rods 3 1 and connect frame members 31 and 32, and frame member33 braces member 32 and the upper ends of the rods. Circuit breaker operating rail 36 is provided with a sleeve, 37 Which hasa pivotal bearing on rod 34,. The sleeve is connected to the rail by flange 38. Preferably, the rail is an angle piece of L section, so that it consists substantially of two flat vertical members 39, 40, arranged at a right angle to each other. From a part of sleeve 37 extends an arm {t5 carrying an insulating block 16, and on this is secured a metal contact 47. This movable contact cooperates with two separated fixed contacts 4 8, 19, from which conductors lead. These conductorsconstitute a part of the controlling circuit of the car, or a special safety circuit so arranged that when it is interruptedby withdrawing contact, 17 the power circuit of the car is interrupted and if desired. a brake is applied. Rail 36 is provided. at a convenient point with an eye located between the meeting point of; the rail members 39 and 10, and the pivot axis 34. A spring 56 is connected at one end to this eye, and at the other end to an arm'57 extending from frame member 32,, the eye 55, pivotv axis 34 and point of spring connection with arm 57 being arranged so that they are all in line when rail 36 ismidway between its two extreme positions shown in Figs. 1 and 4. respectively. The spring thus acts as a yielding detent and op erat-ing device to retain the rail in eitherof its extreme positions, and when it has been moved slightly beyond the central position in either direction to urge it. to complete that movement. i i i Rail36 may be as long as is necessary, to permit the shaft door to be opened with the car a, reasonable distance above or below the landing, and also to permit a reasonable degree of oscillation of the car as it is being stopped, without interfering with the proper action of the safety mechanism.

hen the floor, of the car is reasonably near a landing, whether the power has been completely shut. off or not, or if powerhas been completely shut 0H. whether or not the car is oscillatin or. drifting in either direction to a reasonable extent in stopping, if it is attempted to open the door D, cam operating arm 60 on the door first. strikes cam arm 16 and moves the lower end of lever 12 to the right, Fig. 2. Studs 14 and 18 slide through horizontal slot 3; the cam 15 is prevented from rotating on its axis, and movement of the lever is resisted by spring 19. The initial left hand movement thus imparted to the upper end of lever 12 causes its cylindrical member to first exert a force tending to move safety arm 9 to the left against its pivot 8. Due to the angular relation of hole 26 in the arm to the pivot, the

reaction of forces causes the lever to commovement, being accommodated by slot 13 travelling outward along-fulcrum stud 10. At the same time sincejthe. lever also describes an are about the, axis, 14:, the slot travels upward about the stud The connection of the lower end of the lever with stud 1 1. is sufhci ently loose to permit, the slight oscillation of the lever toward and fromthe shaft wall, this movement being reduced to a minimum at this point. In theoutward swing of arm 9. its point 28 strikes flange 39 of rail 36 and moves the rail on its 34 until it passes its middle position. Spring 56then v urges the rail tocomplete its travel to the position shown in Fig. 1} At the first movement of ra l 36, arm #15 takes the movable contact 47 away from fixed contacts 4:8 and 19 and the controlling or safety circuit is broken, discontinuing or preventing application of power to move the Carin either direction. Continued opening movement of the door brings the end of studi 14L to the beginning of curved portion 4; of the guideslot. Stud let travels around this-curved portion, cam 15 is permitted to rotate on its axis 14, and this movement is aided the action of door arm 60 on cam arm 16. As the cam approaches the position shown in dotted lines in Fig. 2, door arm 60 is freed from the cam and the door may be opened to its full extent. The location of stud 14 inthe end of curved slot 4 looks i the end of arm 9 from the rail, and in the of the guide slot. At this time spring 19 becomes effective to move lever 12, and the door, toward closed position. The upper end of lever 12 moves arm 9 back until its end 28 strikes flange 40 of rail 36 and moves the rail beyond its central position. Spring 56 thereupon completes .movement of the rail and closes the control circuit at contacts &8 and 49. The arm is free from the rail and as the door approaches closed position, lever 12 moves the arm to itsposition of rest within the limits of the wall recess. When the door is completely closed, the parts have resumed their normal position shown in Fig. 2.

It is desirable in some cases to provide means to prevent opening the shaft door unless the car is reasonably near the landing. Theinvention comprises very simple and'effective means for this purpose. A swinging detent member is pivoted to the end of flat strip 6. The outer end of this member has a hook 71. A spring 72 coiled about the pivot urges member '70 toward active position. Near the pivot connection arm 70 has an offset lug 73. In certain cases this limits the extreme outward movement of arm 7 0 by striking the outer face of strip 6. Normally, member 70 is held back against the shaft wall by the rear face of safety arm 9, as shown in Fig. 1. In this position end 28 of arm 9 is separated considerably from hook 71. If it is attempted to open the door when the car is not within safety distance of the landing, a slight movement of the door bringsarm 9 to the position shown in dotted lines in Fig. 1. Because of the separation of pivot centers of arms 9 and 70, at this point hook 71 en gages end 28 of arm 9 and prevents further movement of the arm and further opening of the door. The amount of door opening permitted by this device may be very slight only about an inch, or even less. To render the safety latch ineffective when the car is withinsafety distance of the landing, a

rail 75 is located on the car adjacent the rail 36. Rail 7 5 is provided at one edge with a sleeve 76 having a pivotal bearing on rod In normal position the rail rests against a stop 77 and is urged to this position by a spring 78. Rail '7 5 is'usually considerably shorter than rail 36 and is preferably lo cated vertically midway of rail 36, as shown When the car is within safety range of the landing, this range being indicated by the-length of rail 75, when the door is moved slightly away from closed position, hook 71 strikes rail 75 before it reaches the position shown in dotted lines in Fig. 1. At this time the hook is clear of the end 28 of arm 9. This position is shown'in Fig. Arm 9 can, therefore, complete its travel without interference by hook 71; the door may be fully opened and the normal safety function of arm 9 is exercised as previously described. I u v In some cases, for instance when the door is slightly opened when the car is not near arms back and especially to force the end.

of arm 70 'back so that the hook 71 rests properly against the outer surface o-fthe stop rail.

it 1s also desirable m many cases'to provide-means for preventing damaging contact between arms 9 and 70 and parts of the car proper. For this purpose, the car is provided with a. vertical guard rail 90 terminating in inwardly curved end portions 91. The end portions areso ar-' ranged that whenever the arms extend in any of the positions just above described" iped back by endportions they will be 91 and will then slide along the straight face "of rail 90% the car passes, and any, injury either to the arms or to parts of the car will be prevented. It will be evident that the curved members of rail 75 and the guard rail 90 with its curved end members will only function when the door improperly manipulated, and this is a rare occurrence. V

In some cases the curved end portions 80 of stop rail "5 5 may be omitted. In that case the pivotal mounting of the rail is desirable to take care of certain abnormal conditions such as the following ex; amples: If it is attempted to open the door when the car is fairly near the landing but outside the safety, range, that is, so

that the upper end of rail' 75is below a point opposite hook 71, or the lower end of the rail is above a point opposite the hook, the hook will pass aboveor below the end of the rail as the case may be in reaching the position shown in Fig. 1. where-itlock the door against further movement. lf at' that time the car was novingslightly, sufficient to bring the rail opposite the nor mal position of the hook, the return move, ment of hehook when the dooris fully closed would bring the hook into contact with the rear face of the rail. When the rail is pivotally mounted as described, this return movement of the hook causes the rail to move outward on its pivot against spring 78 until. the hook passesthe edge of'the rail, whereupon spring 78 snaps the rail back to normal position. Or if, when the door is opened, the car is within safety range of the landing but oscillating or drifting somewhat. the hook will strike rail 75 and permit full opening of the door and the safety action of arm 9, but if the drifting movement of the car sutiicient to carry the upp r or lower end o rail 7:") below or above the end of the hook as the case may be, the hook will pass beyond the rail until stopped by in, T3 striking strip 6. If the car then ha return drift or oscillation, the hook will then be bro'. it again within the vertical limits ot rail and on closing the door will be permitted to return to normal position by the pivotal movement of the l. as above described.

It is to be especially noted that tie invention permits such-a. design of parts of the mechanism located on the shaft that they may be all located within a very narrow space perpendicular to the shaft wall. The space or recess provided for these parts may be made as small as 19 inches in the direction indicated, or even less. .lt is also to be noted that in the normal position of the parts there is no part of the safety mechanism either on the shaft or the car which extends into the clearance space between the car and the shaft wall. The normal or desired clearance limits between the car and the shaft are, therefore, not interfered with in any way.

hen a car guard rail such 90 above mentioned is provided, w th the curved or cam shaped ends 91, it s 'ietimes desirable to give to the portions of such ends at one side of the rail an additional rearward curvature as at 95. These portions are those which are traversed by the end of hook 71. By this arrangement, as parts 95 of the rail are about to move out of contact with the hook, the hook is permitted to move outwardly somewhat farther than the end of safety arm 9 which rests on the main surface of the cam ends 91. his additional outward movement of the hook gives added assurance that the hook will correctly engage with end 28 of the safety arm and lock the door against further opening movement until stop rail 75 is properly positioned in relation to the arms, whereupon the arms ill be acted upon and the door may be opened normally. as above described.

What is claimed is:

1. In safety mechanism for elevators, the combination with an elevator shaft. a shaft door, a car movable in the shaft and a control circuit including a circuit breaker, of a vertical, movable rail carried by the car and connected with the circuit breaker. a horizontally swinging arm located on the shaft wall and adapted to cooperate with the rail when the car is near the landing, an ap proximately vertical lever connected with the arm, and cooperative means carried by the lever and the shaft door to move the arm and operate the rail and circuit breaker when the door is opened with a part of 'the rail opposite the arm.

2. ln safety mechanism for elevators, the combination. with an elevator shaft, a shaft door, car movable in the shaft and a control circuit including a circuit breaker, of a vertical, movable rail carried by the car and connected with the circuit breaker, a horizontally swinging arm located on the shaft wall and adapted to cooperate with the rail when the car is near the landing, an approximately vertical lever connected with the arm, a controlling member for the lever pivotally connected to the lower end thereof, a guide for the controlling member comprising a straight portion and a curved detent portion, and a. member carried by the door to cooperate with. said lever controlling member.

3. In a safety mechanism for elevators, the combination with an elevator shaft, a shaft door, a car movable in the shaft and a control circuit including a circuit breaker, of a vertical, movable rail carried by the car and connected with the circuit breaker, a horizontally swinging arm located on the aft wall and adapted to cooperate with the l when the car is near the landing, an

a; proximately vertical lever connected with the arm, a two-armed cam pivotally connected with the lower end of. the lever, a guide comprising a straight portion and a curved detent portion, cooperating guiding means, carried by the cam, and an arm carried by the door and cooperating with the cam between the arms thereof.

ln safety mechanism for elevators, the combination with an elevator shaft, a shaft door, a car movable in the shaft and a control circuit including a circuit breaker, of a vertical, movable rail carried by the car and connected with the circuit breaker, a h0rizontally swinging arm located on the shaft wall and adapted to cooperate with the rail when the car is within reasonable distance of the landin an approximately vertical lever connected with the arm, a two-armed cam pivotally connected with the lower end of the lever, a guide comprising a straight portion and a curved detent portion, cooperating guiding means carried by the cam, an arm carried by the door and cooperating witn the cam between the arms thereof, and a spring urging the lever to closed door position.

5. In safety mechanism for elevators, the combination with an elevator shaft. a shaft door, car movable in the shaft and a control circuit, of a horizontally swinging safety arm pivoted in the shaft, a lever, a connection between the lever and the arm at a point angularly offset from the arm pivot, means cooperating between the door and the lever to a point angularly offset from the arm pivot,

means cooperating between the doorand the lever to operate the lever, said means oomprising a member'movably connected to the lever and movable with it and a guide comprising a detent portion engaged by said member when the lever is in safety position, a spring urging the lever to normal-position, and safety mechanism including a circuit breaker in said control'circuit carried by the car and arranged to cooperate with said arm.

7. In safety mechanism for elevators, the combination with an elevator'shaft, a shaft door; a car movable in the shaft and a corn trol circuit of a horizontally swinging safety arm pivoted on theshaft wall and normally lying close against the wall, a substantially vertical lever normally lying vclosely parallel with the wall and having a connection with said arm at a point an gularlv offset from thearm pivot, a shifting fulcrum for the lever located on the shaft wall. a controlling member movably connected to the lower end of the lever, a guide engaged by the controlling member and comprising a straight portion and a detent portion. a member carried by the door to operate said controlling member.-;a spring urging the. lever to normal position, and safety mechanism including a circuit breaker in said control circuit carried by the car and arranged to cooperate with said safety arm.

8. In safety mechanism for elevators. the combination with an elevator shaft, a shaft door, a car movable in the shaft and a control circuit, of operating mechanism located on the shaft wall comprising a horizontally swinging arm actuated by opening the shaft door, a vertical safety rail of considerable length mounted on the car to swing horizontally upon a long vertical bearing and arranged to be actuated by said safety arm when any point of said rail is opposite the I safety arm, and a circuit breaker in said control circuit operated by said safety rail.

9. In safety mechanism for elevators, the combination with'an elevator shaft, a shaft door, a car movable in the shaft and a control circuit, of operating mechanism located on the shaft wall in a very small space perpendicular to the wall and comprising a horizontally swinging safety arm actuated by opening of the shaft door, a vertical safety rail mounted on the car to swing horizontally and arranged to be actuated by said safety arm when a part of the rail is opposite the safety arm, a circuit breaker'in said control circuit operated by the safety rail,

and'means yieldingly holding the, rail in either safety or normal position and urging the rail to complete its movement toeither position when. moved past mid-position in correspondingdirection. i

10. In safety mechanism for elevators. the combination with an elevator shaft, a shaft door, a car movable in the shaft and a con-, V

trol circuit including a circuit breaker, of

operating mechanism located on the shaft wall in a very small'space perpendicular to the wall and comprising a horizontally swinging safety arm" actuated by opening of the shaft door, safety door-latch mecha, nism comprising a swinging latch armpivoted on the shaft wall and controlled by movement of the safety arm, said latch arm comprising a hook adapted to cooperate with the end of the safety arm, a vertical stop-rail carried bvthe car and-Vadapted'to be enby said latch arm when the rail is op,- posits the arm and prevent latching engagement of said hook with'the end of the safety arm. a-vertical safety rail mounted on the car to swing horizontally and arranged to be actuated by said safety arm when a part of the rail is opposite the safety arm, and a circuit breaker operated by the safety rail.

11. In safety mechanism. for elevators,

the combination with an elevator shaft, a.

shaft door. car movable in the shaft and a control circuit including a circuit breaker.

and means yieldingly holding said stop rail in normal position, the pivotal mounting of said stop rail permitting return of the latch arm to normal position when it is beyond and opposite the stop rail.

12. In safety mechanism for elevators. the combination with an'elevator shaft. shaft door. a car movable in the shaft and a control circuit, of a horizontally-swinging safety arm located on the shaft wall and horizontally swinging latch arm located on operated by movement of the shaft door, a

the shaft wall and having a hook adapted to engage the end of the safety arm and prevent further movement of the door when the door is slightly opened, a vertical stop rail pivotally mounted on the car and adapted to engage the latch arm when the car is within safety distance. of lllllfillllf" and prevent latching engagement with th safety arm, moans yieldingly holding saiu stop rail in normal position, the pivotal mounting of said stop rail permitting turn of the latch arm to normal position when it is beyond and opposite the stop rail a vertical safety rail pivotally mounted on the car and extending" above and below the ends of said stop rail said safety rail comprising two angularly related flanges the safety arm being arranged to cooperate with said safety rail between said flanges, and a circuit breaker in said control circuit operated by the safety rail.

13. In safety mechanism for elevators the combination with elevator shaft, a shaft door car movable in the shaft and a control circuit, of a swinging arm located in the shaft and arranged to project into the path of the car when in active position means controlled by movement of the shaft door to operate said arm, a safety device including a circuit breaker n said control circuit von the car to cooperate with said arm. and guide devices located on the car to prevent damaging contact of the arm with the car.

1%. In safety mechanism for elevators, the combination with an elevator shaft, a shaft doon a car movable in the shaft and acontrol circuit, of a swinging arm located in the shaft and arranged to project into the path of the car when in active position, means controlled by movement of the shaft door to operate said arm, safety mechanism on the car including a circuit breaker in said control circuit and a member to cooperate with said arm. said member having rearwardly curved upper and lower end portions to guide said swinging arm into proper relation to the car safety mechanism and additional guide devices located on the car to prevent damaging Contact of the arm with the car.

1.5. In safety mechanism for elevators. the combination with an elevator shaft, a shaft door, a car movable in the shaft and a control circuit, of a swinging arm located in the shaft and arranged to project into the path of the car when in active position means controlled by movement of the shaft door to operate said arm, and safety mechanism on the car including a. circuit breaker in said control. circuit and amember to cooperate with said arm said member having rearwardly curved upper and lower end portions to guide said swinging arm into proper relation to the car safety mechanism,

16. Safety mechanism for elevators, including the following parts upon the wall of the elevator shaft, viz: a door latch and an actuating member; and the following parts on the elevator ca-r viz: means for releasing said door latch, and safety mechanism operable by said actuating member for preventing movement of the car; the said parts being so arranged that the shaft door cannot be opened except when the elevator is at or near the landing and that the elevator cannot be actuated when the shaft door is open v and being so located when in inoperative position that the parts upon the wall of the shaft lie wholly at one side of a, vertical plane and that the parts located upon the elevator lie wholly upon the other side of said vertical plane.

In testimony whereof I have hereunto .set my hand in the presence of two subscribing witnesses.

PowHA'rAn J. u' oorinnrncn.

Witnesses ADELE S. EBERHARDT, D. M. SMITH. I

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