US1132744A - Safety device for elevators. - Google Patents

Description

E. A. SMITH.

SAFETY DEVICE PoE ELEvAToEs. APPLIOATIONIILED FBBJ, 1905.v

1,132,744.. .Patented Mar'. 23, 1915.

L.0 o /,//-?6'/J'/ f/ f Z/A z Y WITNESSES: INVENTOE L I EMME- LAM wg BY THE MORRIS PETERS CO., FHDTo-LITHO.. WASHINGTON. D. L

* Unir ears i EDWARD A. SMITH, or NEW YORK, N. Y., assIGivoR To oTis ELEVATQR coiviraivn r `CORPORATION 0F NEWUERSEY.

l SAFETY DEVICE FOR ELEVATORS. Y

To all whom it may concern Be it known that linwannv A. SMITH, a citizen of the United States, residing at New York city, in the county-vof New a'ork and State of New York, have invented certain newl and useful Improvements in Safety Devices for Elevators, of which the following is a specicaticn.

My invention relates to a safety device for elevators and its Objectis toiinprove upon structures of this kind now in use and to` provide a device for quickly andv positively clamping an elevator car to the guidesove which it is ladapted to run. Y

I lwill describe my invention inthe following specification and point out the novel features thereof in claims.'

Referring'tothe drawings, lFigure 1 is a diagrammatic view in elevation of an eleva-V tor car and certain connected apparatus which is used in carrying out my invention.`

Fig. 2 is a plan view, partly in section, of my safety device, showing sections ofthe guides which it is intended to clamp. Fig.

3 is a plan view of a mcdiiication of my'device. Figs. 4 and 5 show-two other modificationsof my invention. Fig. 6 is an en-A tom of which my device is attached.

11 is a hoisting rope for the car.l p 12 is a governor rope connected to run with the car. This governor rope runsunder a sheave 13 situated near one end of.

the cars travel. It may be weighted, as at 15, and pawls 16, 16 may be provided if de sired and radapted to engage with ratcliets in the sides yof the weight to prevent its up- Y.

ward movement.v The governor rope 12 runs over another sheave 14 near the other end of the cars travel, which is connected to a governor'or speed regulator 17 by suitable gearing 18. The speed governor is arranged to actuate a gripping device 19 which grips and Vpositively locks the governor rcpe when the car runs A'in excess of normal speed. It `may be arranged to op-- crate when the car is running in either di- Y rection. The governor rope, is yieldingly connected to the car at 12 and is so arranged i i that when the lgovernor rope l2 isv stopped 4 Specification of Letters Patent. Pattedlwrtgg"1915. appiicauonsiearebruary 6,1905. seriaiivaaeinci. 'i l impait a rotary motion to the winding drum 3l. It is sometimes desirable to rotate ,the

winding drum 31 by handl frcin the car, and for this purpose I provideanother rope 12C on the winding druml and attach to this rope a handle 12D- withinreach' ofthe operator in V the car.

i Wai now referto Fig. 2 and fiesen-be are 'I clamping device `or safety device for the elevator car which is there illustrated. yThe Winding drum is rotatably4 mountedfuponhubs 35, 35 on rigid brackets 34', -34. .The p l Y l l drum may be grooved as shown at 32 for the reception of. 'the' rope '125,.and vseparate grooves 33 may be added if desired forthe reception of the rope 12C. `The inside lof the drum vis bored cut'toy receive two, shafts-36, 36, the outer ends of which arethreaded one V,with a left hand threada'nd theother'with Y i a right handthread. Feathers 436, 36 are'` provided which engage with the drum and Vthe shafts, so that the shafts will turn" with 3 V the drum but are 'atthe -saine timeY freeto move longitudinally. The threadedendsof-A kthese shafts, one of which 3Tis'shown in the drawing, run through collars 38, 38 which are threaded on theinside to i'it the threads von the 'shafts 36. The collars 38 'are also i threaded on the outsidewith right and left.y

`hand threads respectively of liigher-'pitch ywhich fit into similar threads inthe rigid l 1 brackets 34, Thus the collars 38, 38

form dier'ential screws each having a highpitch thread and a low'pitch thread.

, Wherever I use the expression reasons which will be pointed out later.' Near the ends of the shafts 36, 36, collars are -105 provided asfshown at '39;v Vedge- shaped cams 25, 25 lz irearrang'ed to bel movedjby the collars 38 andthe 36 between ant-ifl y raro. g

ioo

friction rollers 24, 24. These rollers areon the ends of the jaws 21, 2l`of a clamping device. The jaws 21, 2l are pivoted/ at '23 and are arranged to be moved into engagei Collars. rFliese by reason of their high pitch will cause the cams 25, 25 to be quickly pushed apart and between the rollers 24, 2% until the jaws 2l, 21 are brought into contact with the guides 22, 22. The further movement of the sleeves 3S, 33 will then be resisted by the back pressure on the cams 25 and they will move no farther, but the continued movement of the shafts 36 will now push the low pitch threads 37 through the collars and theywill continue to move the cams 25, 25 between the rollers 241A, 24. at less speed but with greater power and so cause the clamping device to be tightened firmly on the guides 22, 22. rlhis will be `continued until the. car is brought to rest vends of the sleeves 38.

thereby, when the movement of the drum 3l will cease. rl`he peculiar shape of the high pitch threads on the outside of the sleeves 38 will prevent the latter being pushed back bythe back pressure on the cams 25, 25 because their long sloping sides will be in effectrwedged into the corresponding sides of the internal threads in the brackets 3l, 34. TWhen, however, it is desired to release the clamping device from the guides, the drum 3l` may be turned back by hand or otherwise, the low pitch threads will work back into the sleeves38, 3S until the collars 39, 39 which are secured to their respective shafts abut the sleeves whenthey will be moved back to their original positions. lf desired, springs 21A, 2lA may be provided to move the jaws 2l, 2l away from the guides when the cams 25, 25 are drawn back.

lt should be noted that when the high pitch and low pitch screws are re-set so that the low pitch screws will work back into the sleeves 38,' 33, until the collars 39, 39 abut the outer ends of the sleeves the high pitch screws and low pitch screws will be clamped together. That is to say, not only Y is the sleeve 3S held on the screw 37 by friction at the screw threads but also by friction between the collars 39 and the outer rThe arrangement may thereforebe such that when the clamping jaws meet resistance not only must the friction of the low pitch screw threads loe overcome but also the friction at 'the clamp` mg connection between the collar 39 and the outer end of the sleeve 38.

In the modification shownin Fig. 3, a

single high pitch and low pitch screw is shown at 38 and 37which will work in a yoke or frame 30. Ilhey are arranged to be actuated as m the former case by a winding drum 3l and to apply clamps 21',

2l', to the guides 22, 22, in this case by means of levers 26, 26, of which said clamps form an integral part. These levers 26, 26, are pivoted together and to the frame 30 Fig. 4 shows another modification in which instead of high pitchthreads, the cam surfaces Lit), 40 are attached to the drum and are arranged to co-act with similar surfaces 41, 4l on collars 42, 42, the insides of which are provided with low pitch threads 43, 1-3. ln this case the shafts 36A, 36tshould be so arranged that they cannot rotate, which is often of distinct advantage. Another advantage of this arrangement is that the friction on the low pitch threads may be adjusted by means of the bolts shown at 45.

F ig. 5 shows anotherV modification in which the high'pitch screws 38A, 38A are inside of the winding drum 31B and are arranged to push collars 50, 50 outward. rl`he latter cannot rotate until projecting lugs 51 run out of engagement with fixed lugs 52. This insures the hi gh pitch thread acting before the low pitch thread. The lugs 52v may be made of such length that the projecting lugs 5l will run out of engagement with them before the aws engage with the guides.

'l` he above description serves to illustrate some of the modifications and uses of my invention. lts advantages are obvious, for with it the elevator safety device is quickly brought into operation and then the car is brought to a gradual and easy stop.

Many other modifications of my invention may be made without departing from its spirit. y

l have described the clamping device as on the elevator car, as that is the usual position for such devices, but it may be placed on any desired part of the elevator svstem, as for example on the car counterweight.

Having described my invention, what I claim is:

l. The combination of an elevator car, a clamping device therefor, guide rails coperating with said car and device, and a differential screw having a high pitch thread and a low pitch thread for actuating the clamping device, cooperating parts in en gageinent with said threads with different Adegrees of friction, the operation of said screw being controlled by thedierence of threads and coperating parts, so that the lowr pitch thread is brought into operation, and the high pitch thread is held from operation by the resistanceencountered when clamping device engages the guide rails.

`2. The combination of an elevator car, a

Vclamping device therefor, guide rails coperating with said car and device, a high pitch screw and a low pitch screw, coperating parts engaging said screws with difsaid clamping device, a high pitch screw ar-V ranged to move the clamping device quickly and a low pitch screw arranged to tighten` the clamping device, said screws being separate and independently movable, and coperating parts in frictional contact with said screws, the independent movement of lthe screws being controlled by vtheir relative friction withsaid coperating parts, so that the low pitch screwV is brought into operation and the high pitch screw is held from operation by the resistance encountered when the clamping device engages the guide rails.

4. In a safety device for elevators, the combination ofV a car, a clamping device therefor, means for moving the Vclamping device Vquickly until its movement meets resistance, and additional means brought into action by such resistance for imparting a further movement to the clamping device.

5. In a safety device for elevators the combination of a car, a clamping device therefor, means for moving the clamping device quickly until its movement meets resistance, and additional means brought into action by such resistance for imparting a further movement to the clamping device with greater force.

6. 'lhe combination of a car, guides therefor, a clamping device on the car, a differential screw having a high pitch thread and a low pitch thread, coperating parts in frictional contact with said screw, said screw beingarranged to move the clamping device quickly against the guides and then to tighten it on the guides and controlled in its operation by the frictionV of said screw and coperating parts, so that the lowA pitch threadis brought into operation andthe high pitch thread is heldfrom ,operationl by the resistance encountered when the clamping device engages the guides.

7.. In a safety device for elevators, the

combination of a car, a guide over which.r the car is adapted to run, a clamping device i on the car, a high pitch screw arrangedv to move theclamplng device against the guide, a low pitch screw arranged to tightenthe clamping device on the guide, said low pitch screw having frictional connection with the y high pitch screw controlling the relative movement of the screws so that when thev low pitch screw is brought ,into operation 75 the high pitch screw is held from-operationV by vthe frictional `resistance encountered a when the clamping device Vengages the said guide. l 8. In a safety'device for elevators, the combination of a car, guides over which` the car is adapted to run, a clamping device on: the car, a .high pitch screw arranged to move the clamping device against the guides, a low pitch screw arranged to tighten the clamping device onthe guides, parts in frictional contact with and cop` erating with the high pitch screw, and means for actuating the screws by the motion of the car, the operation of said screws being 9&1?. dependent upon the friction between one of the said screws and coperating parts, so that when the low pitch screw is brought into operation the high pitch screw is held from operation by the resistance encoun tered when the clamping device engages the guides.

9. In a safety device for elevators, theV combination of a car, guides over which .the car is adapted torun, a clamping device on 1001 the car, a high pitch screw arranged Ato move the clamping device againstfthe guides,v a low pitch screw arranged `to tighten lthe clamping deviceon the guides, parts with which one of said screws cooperates and is in frictional contact, meansY for actuating ,the screws vby the motion of the car, and additional means for actuating the screws by hand, the oper-1 ation of said screws being controlled by the Vfriction between said high pitch screw and coperating parts, so that when lthe vlow pitch screw is brought'into operationthe high pitch screw is held from operation by the resistance encountered when the clamp-" ing device engages the guides.

10. In a safety device for elevators, the

combination of a car, guides over which the car is adapted to run, a clampingdevice on the car, a high pitch screw arranged to 12` move the clamping device against Vthe guides, al low pitch' screw arranged yto tighten the clampingA device on the guides,` parts coperating with the screws and in frictionalfcontact with one of them,l and V means for actuating the screws by the motion of the car when the car speed reaches VVa predetermined limit,rthe operation ofsaid screws being dependentjupon the` friction `between onek of saidiscrews and coperat-.lSOf

ing parts kso that when the low pitch screw i is'fbrought into operation the high pitch screw is held from operation by the resist-- ance encountered when the clamping device engages the guides.

11. i'he combination with an elevator car, l guides over which the car 1s adapted to move, a clamping device on the car, a high pitch screw arranged to move the clamping device against the guides, a iow pitch screw frictionally connected to said high pitch screw and arranged to tighten the clamping Adevice on Lthe guides, thel operation of one of said screws being dependent uponl the friction between said screw and cooperating gages the guides, and a governor' connected to be Vrun by the car and arranged to actuate the screws when the speed of the car reaches a predetermined limit.

12. 1n an elevator safety device, the combination of a car, guides therefor, clamping devices adapted to engage with the guides, right and left hand differential screws each having a high pitch thread and a low pitch thread, arranged to operate the clamping devices, parts coperating with said screws and in frictionai engagement therewith, the operation of said screws being dependent upon the friction between said screws and coperating parts so that the low pitch. 'screws are brought into operation and the high pitch screws are held from operation by the resistance encountered when the clamping devices engage the guides.

13. The combination of a car, guides therefor, clamping devices adapted to engage the guides, right and left hand screws of high pitch arranged to move the clamping devices quickly against the guides, right and left hand screws of low pitch arranged to tighten the clamping devices on the guides, threaded members with which the high pitch screws are in frictional contact, and means for effecting the successive actuation of said high and low pitch screws, the successive actuation being governed by the difference of the friction between said high and low pitch screws, and the friction between the threaded members and high pitch screws, so

14. In an elevator safet device the combination of a car, guides therefor, clamping devices adapted to engage the guides, right and left hand screws arranged to move the clamping devices quickly against the guides,

right and left hand screws of low pitch a'rl ranged to tighten' thefciampmg devices on the guides, `screw threaded members cooperfor such operation, so that the low pitchv screws are brought into operation and the high pitch screws are held from operation bv the resistance encountered when the clamping devices engage the guides and means for actuating the screws by hand.

15. The combination of a car, guides therefor, clamping devices adapted to engage the guides, right and left hand screws, arranged to move the clamping devices quickly against the guides, right and left hand screws of low pitcharranged to tighten the clamping devices on the guides, screwthreaded members coperating with the Vscrews with different degrees of friction,

said screws being dependent upon said difference of friction for such operation, so that the low pitch screws are brought into operation and the high pitch screws are held from operation by the resistance encountered when the clamping devices engage the guides and means for actuating the screws by the movement of the car.

16. fn an elevator safety mechanism, the combination with hoistway rails, of friction members adapted to engage said rails, a device having portions provided with threads of the same kind or direction but of different pitch, means connect-ing said threaded portions to said friction members, and means for automatically rotating the said device to lcause said friction members to be moved at first quickly and then more slowly by reason of difference of friction at said threads of different pitch so that the portions having low pitch threads are brought into operation and the portions having high pitch threads are held from operation by the resistance encountered when the friction members engage said rails.

17. ln a safety device for elevators, the combination with hoistway rails, of friction members adapted to engage said rails, a device having diiferential threaded portions, means connecting said threaded portions to the said friction members, and means for automatically rotating said device to cause said friction members to be moved at first quickly and then more slowly by reason of difference of friction at said threads of different pitch so that the portions having low pitch threads are brought into operation, and the portions having high pitch threads are held from operation by the resistance encountered when the friction members engage the said hoistway rails.

18.' In an elevator safety device, Iho'istway rails, friction members adapted to rengage'- saidrail's, and a differential screw dependent upon difference inV friction at the screw threads to operate one of said members so l resistance encountered when the that when the portions of said screw having low pitch threads are brought intol operation the portions having high pitch threads are held from operation by the resistance encountered when the friction members engage the hoistway rails.

19. In an elevator safety device, hoistway Y said screw being dependent for its operation upon difference of friction at the yscrew threads so that when the portion having the low pitch threads is brought into operation the portion with the higher pitch threads is held from operation by the resistance encountered when the jaws engage the guide rails. t

21. In a safety device VforA elevators, the combination with hoistway rails, of gripping jaws adapted to engage said rails, positive means for operating said gripping jaws, and means for automatically increasing the pressure and decreasing the motion of said jaws when they come in contact with said rails.

combination with hoistway rails, of grip ping jaws adapted to be mounted on the car and engage said rails, positive means for operating said grippingv jaws, and means actuated by resistance of said rails to the motion of said jaws for' increasing the pres-V sure and decreasing motion of said jaws Y when they engage the rails.

23. In a safety device for elevators, the combination with hoistway rails, of gripping jaws adapted to engage said rails, a differential screw dependent upon difference 22. lIn a safety device for elevators, the

of the friction opposing the operation of said screw to operate said gripping jaws, Y and means for automaticallyoperatmg said screw so that when the part having low pitch threadsV is brought into operation the Y parthaving high pitch threads is held from operation by the resistance encountered when the gripping jaws engage lthe hoistway rails.

24. A safety device-for elevators, comprising a drum, a safety rope for turning the drum, brakes, members connected'with the j drum, rods for operating the brakes, said rods being connected with the members to move endwise and means dependent upon difference of friction opposing said members for first imparting a bodily endwise movement to the members and rodsy so as to apply the brakes quickly on rotatingthe drum and subsequently rotating said members in unison with the drum to impart endwise move@ ment to the rods for actuating the brakes slowly and more powerfully, said quick operation being retarded and the slow operation effected by the resistance encountere when the brakes are applied. Y 25. A safety device for elevators, comprising a drum, a'safety rope, the endsof which are secured to the drum, brake levers, journal bearings for the drum, members connected with the drum, rods having heads at their outer ends for operating the brake levers,

vsaid rods being carried by the members and connected therewith to move endwise, and

means dependent upon difference of frictionV opposing said members for first imparting a bodily endwise movement to the members and rods to apply the brakes quickly on ro` tating the drum and subsequently rotating the said members in unison with the drum tol impart endwise movement to the rods for actuating the brake levers slowly 'and more powerfully, said quick operation being retarded and the slower operation effected the resistance Vencountered when the brakes are applied.

In witness whereof, I have hereunto signed lmy name in the'presence of two subscribing Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.V

. Washington, D. C. Y

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