US568521A

US568521A - Arthur e

Info

Publication number: US568521A
Authority: US
Publication date: 1896-09-29
Anticipated expiration: 1913-09-29

Description

(No Model.) v

A. R." CLARKE.

SAFETY DEVICE EOE ELEVATORS.

Patented Sept. 29, 1896.

Ilivirnn STATES -ATRNT rrrcn.

ARTHUR R. CLARKE, OF CHICAGO, ILLINOIS,`ASSIGNOR OF ONE-HALF TO LYNDEN EVANS, OF SAME PLACE.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 568,521, dated September 29, 1896.

Application iiled October 2, 1895.

To @ZZ whom t may concern.:

Be it known that I, ARTHUR R. CLARKE, of Chicago, in' the county of Cook and State of Illinois, have invented certain new and useful Improvements in Safety Devices for Elevators; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanyin g drawings, and to the letters of reference marked thereon, which form a part of this specification. i

This invention relates to improvements in elevators, and pertains more specifically to improvements in safety devices designed to automatically engage a fixed part of an elevator shaft or well upon the breakage of any part of the hoisting apparatus, so as to prevent the elevator from dropping.

Described more particularly the invention embraces a gripping device carried by the elevator-car provided with a jaw or engaging member which travels adjacent to and tends to normally close upon or engage a suitable way or structural part of the shaft. under spring-tension, but which is normally held free from engagement by the tension of the hoisting-cable of the car, so that whenever such tension is released the gripping device will instantly engage and prevent any substantial descent of the car, the construction and arrangement being such that the greater the weight of the car the more firmly will the gripping device be forced into engagement.

The object of the invention is to provide an improved construction in devices of the character above referredto; and it consists of the matters hereinafter described,and more particularly pointed out in the appended claims, and will be readily understood from the following description, reference being had to the accompanying drawings,in which- Figure l is a rear elevation of an elevatorcar equipped with my invention. Fig. 2 is a central vertical section of the lower part of a car and safety device applied thereto, taken on line 2 2 of Fig. l. Fig. 3 is a bottom plan view of the same, showing the guideways of the elevator-shaft in horizontal section. Fig. 4 is a View similar to that of Fig. 2 reduced in size somewhat, showing a modification. Fig. 5 is an enlarged fragmentary detail of the end Serial No. 564,392. (No model.)

of the gripping-bar and the eccentric carried thereby.

As shown in said drawings, A designates as awhole an elevator-car which may be of any usual or desired construction and is mounted to slide upon suitable ways B/ B', secured vertically upon the framework of the elevatorshaft B, as usual. The ways B/ B, which serve to guide the elevator-car within the shaft, are arranged centrally of the opposite sides of the shaft and are preferably constructed of woodof substantial strength to afford a certain and reliable hold for the gripping devices, as hereinafter described.

present invention they are for the sake of clearness and brevity omitted from the description and drawingsherein.

Now referring to the safety devices, E designates asa whole a rigid swinging frame pivoted to the car, preferably to the bottom side thereof, soas to oscillate on a horizontal axis extending transversely of the car and parallel with the plane of the Ways B B. The frame E has pivotal engagement with the car A by means of horizontally-slotted bearings secured to the under side of the car at some distance apart, with which slots the pivot e of the frame E is engaged, so as to afford a limited reciprocatory movement of the frame back and forth, said pivot being herein shown as conveniently formed by means of a straight rod or shaft E', rigidly secured at each end to the frame E and extending through said slots. The frame E embraces side members or bars E2 E2, which are of proper length and are arranged to extend rearwardly and obliquely downward from the point of pivotal attachment of the frame with the car A to vpoints between the Ways B B and some distance below or removed from the bottom of the car. Said depending rear ends of the members E2 are curved upwardly and have rigidly secured thereto a gripping-bar E3, which extends between the ways B E and is notched or recessed at each end, as at e e, to receive the latter, those portions of the bar extending on cach side of or embracing the ways forming pairs of biting jaws c2 c3 c2 e3, adapted for engagement with the opposite sides b l1 of the ways I3. The width of said notches or recesses e' is greater than the thickness of the ways B', so that when said bar is carried to the position shown in the drawings, with its plane inclined somewhat from a horizontal plane, just sufficient room will be provided for the ways to pass freely through said notches, but when the free end of the frame E is swung upwardly upon its pivotal axis, so as to approach the bottom of the car, the biting jaws e2 e2, moving on an are struck from said pivotal axis, will be caused to wedge against or into the sides of said ways B and thus arrest the downward movement of that end of the frame E. The further descent of the car will carry the front or pivotal end of the frame downward, thus oscillating said frame on a pivotal axis extending through points c'l c4, formed by the engagement of the jaws e2 e2 with the front sides of the ways, (such oscillatory movement being permitted bythe slotted form of connection of the frame E with the bottom of the can) and thus bringing the opposite jaws e2 ci into biting contact with the opposite sides b of the ways B.

E4 designa-tes an arm rigidly secured to the free end of the frame E, extending rearwardly therefrom and carrying at its outer rear end a t1'ansversely-arranged supporting-bar E5, with which the bottom of the car is adapted to come into contact after the foregoing-described engagement of the gripping devices has taken place and before the car has descended sufficiently to bring the bottom there of into direct contact with the bar. E3, thus serving to arrest the further descent of the car.

EG E designate springs, herein shown as having the form of flat steel straps or plate springs, which are secured to the bottom side of the car and extend at their free ends beneath the supporting-bar E5, said springs being arranged to tend to normally lift or draw the swinging frame E upward toward the bottom of the car.

Obviously means for holding the gripping devices normally out of engagement with the ways and in position to permit the latter to pass freely through the jaws of the gripping bar, controlled by the tension of the hoistingcable, may be constructed in various forms, but a practical and preferred form (illustraied herein) is constructed as follows:

E E designate a pair of levers pivotcd between their ends upon suitable supports rising from the upper side of the car, said levers being arranged with their opposite ends extending outwardly above the side edges of the car and with their inner ends terminating near the hoisting-cable. The outer ends of the levers F are connected with the swinging frame E by means of vertically-extending rods or links F E', which extend downwardly along the side of the car and are connected by means of suitable loops or eyes f with a transversely-extcnding rod or shaft E7, secured to the frame E. The opposite or inner ends of said levers F are each connected with the hoisting-cable by means of cables G G, connected with said levers and with an adjustable clamp or clip l-I, mounted upon the cable at some distance above the levers. Said clamp Il is herein shown as comprising a clampin g-ring 7L, provided with a clampingbolt h in the usual manner, by means of which it may he closed upon the cable, and having a depending tubular sleeve portion h2, exteriorly screw-threaded, through which the cable passes. Upon said sleeve portion is mounted to slide freely a collar 7L, provided on each side with eyes h" h4 for the engagement of the cables G G.

h5 designates an adj usting-nnt threaded upon the exterior of the sleeve 7b', by means of which the collar 7b2 may be raised or lowered thereon.

In use the clamp II will be so adjusted as to hold the inner ends of the levers F F elevated in the position shown in Fig. l, so as to depress the swinging frame E against the tension of the springs E6 E into position to permit the ways to pass through the gri ppin gbar freely when the hoisting-cable is taut. Obviously, when thus arranged, if the hoisting-cable should break or its support in any way become loosened, so as to release the tension thereon, the levers would be released and the springs EG E6 would instantly draw the swinging frame E up into position to cause the grippingbar thereof to engage with the ways in the manner hereinbefore described and thus arrest the car. As an additional safeguard to insure this drawing up of the swinging frame independently of the springs EG E6, I have provided coil-sprin gs I I, secured to the upper side of the car and acting upon the inner ends of the levers E F to draw the latter downward when released.

From the foregoing description it will be seen that I have provided a safety device of simple construction and certain action and that the construction and operation are such that the car will be arrested almost instantly upon the breakage or giving away of the hoisting apparatus and before the car has dropped sufficiently far to acquire any considerable amount of momentum. This is a feature of much importance, inasmuch as it is very difficult to provide safety devices which will not be liable to become unstable or broken under the excessive strain incident to stoppin g a car after it has acquired the momentum of falling a considerable distance,whereas the device herein shown, by .reason of its prompt action in arresting the car, requires to be but little stronger than sufficient to support the IOO XIO

weight of the car when standing, in order to be perfectly safe. Such prompt arrest of the car before it has acquired any considerable momentum also prevents injury to the ways by the gripping devices when arresting the car. v

While I have herein shown what I deem the most practical construction now known to me, yet it will be obvious that various modifications may be made without departure from the spirit of the invention and withoutinvolving more than ordinary mechanical skill. For instance, in Fig. 4 I have shown a modification in which, in lieu of the gripping or bitingjaws e2 e2, the gripping-bar E3 is shown as provided with eccentrics e5 e5, pivotally mounted upon the bar in position to engage the sides h of the ways B when the gripping-bar is swung upwardly, and opposing jaws e6 e6, which coact with said eccentrics to clamp the interposed ways in an obvious manner. Such a construction has the advantage of being less liable to injure the ways, but at the same time has a perfectly reliable engaging or gripping action. I do not therefore wish to be limited to the precise details of construction shown, nor to the particular application of my invention above described. The particular construction shown is, however, as hereinbefore stated, believed to be specially desirable not only in the general invention, but in the matter of detail, and such construction has therefore been made the subject of specific claims.

I claim as my inventionl. The combination with an elevator-shaft and an elevator-car guided therein by means of vertical ways located at each side of the car, of a gripping device pivoted horizontally to the bottom of the car with its pivotal axis arranged parallel with the plane of said ways, said gripping device having pivotal engagement with the bottom of the car by means of horizontally-slotted bearings and being provided with gripping-jaws at its free end adjacent to said ways, a spring tending to normally oscillate the gripping device upwardly upon its pivot into engagement with said ways, whereby the carv is permitted to have a measurable downward movement after the gripping-jaws have engaged the ways before theybegin to arrest the car, and means controlled by the tension of the hoisting-cable of the car for normally holding the gripping device free from engagement, substantially as described.

2. The combination with an elevator-shaft and an elevator-car guided therein by means of vertical ways located at each side of the car, of a gripping device pivoted horizontally to the bottom of the car with its axis arranged parallel with the piane of said ways, said gripping device having pivotal engagement with the bottom of the car by means of horizontally-slotted bearings, permitting a limited bodily reciprocatory movement of the gripping device and said gripping device being provided at its free end adjacent to said ways with gripping-jaws, a spring tending to normally oscillate the gripping device upwardly upon its pivot into engagement with the ways and means controlled by the tension of the hoisting-cable of the car for normally holding the gripping device free from engagement, comprising an oscillatory lever pivoted between its ends to the car, a link connecting one end of the lever with the gripping device and operative connections between the opposite end of the lever and a hoisting-cable whereby when the latter is held taut the gripping device will be held out of engagement, substantially as set forth.

3. The combination with an elevator-shaft and an elevator-car guided therein by means of vertical ways located at each side of the car, of a gripping device pivotally connected with the bottom of the car by means of slotted bearings, permitting a limited bodily reciprocatory movement of the gripping device and arranged parallel with the plane of said ways, said gripping device comprising a supporting-frame arranged to depend obliquely downward and carrying at its free end a gripping-bar arranged to extend between the ways and provided on each end with gripping devices extending on the opposite sides of the ways, a rearwardly-extending bar connected with said supporting-frame, a transversely arranged supporting -bar mounted thereon, a spring connected with the bottom of the car and tending to normally draw said gripping devices upward toward the bottom of the car and means for holding the gripping devices depressed, comprising levers pivoted between their ends to the upper part of the car, links connecting the ends of the levers with the supporting-frame of the gripping device and cables connecting the opposite ends of the levers with the hoistin g-cable, substantially as set forth.

4. The combination with an elevator-shaft and an elevator-car guided therein bymeans of vertical ways located at each side of the car, of a gripping device pivotally connected with the bottom of the car by means of slotted bearings permitting a limited bodily revciprocatory movement of the gripping device and arranged parallel with the plane of said ways7 said gripping device comprising a supporting-frame arranged to depend obliquely downward and carrying at its free end a gripping-bar arranged to extend between the ways andpprovided on each end with gripping devices extending on the opposite sides of the ways, a rearwardly-extending bar connected with said supporting-frame, a transverselyarranged supporting-bar mounted thereon, a spring connected with the bottom of the car and tending to normally draw said gripping devices upward toward the bottom IOO IIO

of the car and means for holding the gripping devices depressed, comprising levers pivoted between their ends to the upper part of the car, links connecting the ends of the levers 'of the said Ways, and means for Oscillating said bar on its longitudinal axis to bring the gripping devices into engagement with the Ways, substantially as described.

In testimony that I claim the foregoing as my invention I affix my signature, in pres enee of two nf'itnesses, this 27th day of September, A. D. 1895.

ARTHUR R. CLARKE.

Vitn esses:

WILLis D. SHAFER, ALBERT H. GRAVES.