US460874A

US460874A - john k

Info

Publication number: US460874A
Authority: US
Publication date: 1891-10-06
Anticipated expiration: 1908-10-06

Description

(No Model.) 2 Sheets-Sheet 1. J. K. JOHNSON.

SAFETY DEVICE FOR ELEVATORS.

No. 460,874. Patented Oct. 6, 1891.

1 lmllmwhin HMW .lll l avwa'wlioz 70701, JZ'. Jo hndon.

2 Sheets-Sheet 2.

(No Model.)

J. K. JOHNSON. SAFETY DEVICE FOR ELEVATORS.

. I I Ii .1

Patented Oct. 6, 1891.

Jhm/Zl 7o/znw0n.

UNITED STATES PATENT OFFICE.

JOHN K. JOHNSON, OF \VASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OF ONE-HALF TO FRANCIS F. BURDETT, OF SAME PLACE.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 460,874, dated October 6, 1891.

Application filed May 21, 1891. Serial No. 398,533- (No model.)

To (ZZZ whom it may concern.-

Be it known that 1, JOHN K. J OHNSON, a citizen of the United States of America, residing at Vashington, in the District of Columbia, have invented certain new and useful Improvements in Elevators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it apro pertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

This invention relates to certain new and I 5 useful improvements in elevators; and it consists more especially in providing means for raising and lowering the elevator cage or car and arresting the downfall of the same in case of a break in the hoisting rope or ropes or in the mechanism for operating said ropes; and it further consists in providing an improved form of hoisting-drum or Windlass and in providing the case with safety-catches which are adapted to engage with the rack-bars at 2 5 the sides of the elevator-shaft, so that said safety-catches will engage with the rack-bars and be held in locked engagement therewith should the hoisting rope or ropes or mechanism for operating the same be broken and the cage otherwise fall.

In the accompanying drawings, forming part of this specification, Figure 1 is a side view, partly in section, of an elevator shaft and cage, showing my improvements applied thereto. Fig. 2 is a detail view, partly in section, of a car and partly of the elevator-shaft, showing one form of catch in locked engagement with the rack-bar. Fig. 3 is an end view showing the side of the cage and the Windlass or hoistingdrum. Figs. 4 and 5 are detail perspective views.

A A designate the vertical beams of the elevator-shaft, which are provided with the usual rack-bars a a. The upper connecting cross-beam A at the top of the elevator-shaft carries guide pulleys I) and b, over which pass the hoisting-rope B and safety-rope C. The hoisting -rope is preferably of about twice the diameter of the safety-rope and is attached to the upper part of the elevatorcage in the usual manner and passes over the guide-pulleys on the upper cross-beam and from there downward to the drum B of the Windlass D. The safety-rope O is attached to the movable cross-bar E, located within the 5 5 cage or car, and passes through the upper rigid cross-piece of the cage, over the pulleys carried by the upper cross-beam A and from there down to the drum C of the Windlass.

The cross-bar E has attached thereto vertical side bars F F,which pass through suitable guides or loops f f and are drawn down by springs attached to their lower ends and to the cage. These side bars are provided with recesses f, and the sides of the cage adjacent thereto are recessed or cut away for the reception of castings or fixtures II, which support pivoted pawls or catches 7b, as shown. The pawls or catches are curved on one side, and with said curved edges pins f carried by the vertical bars F F, engage, said pins being located a short distance below the recesses f, so that when the bars F are in their normal position-that is, at the limit of their downward movement-these pins will bear against 7 5 the lower ends of the pawls to hold the upper ends thereof out of engagement with the rackbars a. The upper part of the casting or fixture H has a recess, within which is placed a gravity locking-pin i, which is adapted to engage the notched portion of the pawl when said pawl is in engagement with the rack-bar co, and when the pawl is out of engagement with the rack-bar it rests upon the upper portion thereof. This pin provides an automatic 8 5 lock for the pawl in addition to the lock pr0- vided by the pin f In Fig. 2 of the drawings the bars F F are shown as being connected to the floor of the cage by springs 75, which springs exert a downward pull upon said bars sufiicient to overcome the spring-pressure of the movable drum 0, over which the safety-rope passes.

In addition to the catches located in the sides of the cage I provide, in some instances, a bottom lock attached beneath the floor of the cage, said lock consisting of bolts K K, which are carried by a frame or casting K, having depending apertured lugs 70, in which the bolts K move. These bolts are drawn Ico toward each other by a spring and have stoppins Z Z for limiting their inward movement,

7 cause the rotation of the drum O against its and between the inner and outer lugs are eyebolts or perforations, to which are attached chains or flexible connections m, which pass over guide-pulleys m and are attached to the lower ends of the vertically-moving bars F.' The bolts K have vertical perforations n, and the floor of the cage is provided with vertical apertures, in which lie locking-pins i, which are adapted to rest upon the upper edges of the bolts when they are withdrawn and enter the recesses n when the bolts are projected.

It will be noted that the safety catches or bolts K will act in unison with the catches or pawls h and that either one or the other may be dispensed with without atfectin g the other. The hoisting-Windlass D is provided with a shaft d, which is supported in suitable bearings and turned in the usual manner, said shaft having rigidly fixed thereon a drum 13, over which the hoisting-rope B passes. The end of this drum is provided with a clutchface 11 which engages with the clutch-face c of the drum 0', over which passes the safetycord 0, the clutch-faces being held in contact a with each other by a spring D on the shaft d. The pressure of this spring can be adjusted to force the clutch-faces against each other with a greater or less amount of pressure, as may be desired, by turning the nuts 0 at one end of the threaded shaft. The object of providing such construction is that should the hoisting-rope break and the engine continue to drive the shaft of the Windlass the drum 0 would slip on the shaft, the strength of the safety-cord being such that it would frictional contact with the fixed drum.

From the foregoing description it is obvious that when the hoisting-rope breaks the pressure will be uponthe safety-cord so as to ele vate the cross-bar E and automatically throw the safety-catches in engagement with the rack-bars to prevent the descent of the cage, and that as soon as these safety-catches are thus causedto engage with the rack-bars they will be locked.

To unlock the catches it will be necessary for the operator to insert a suitable tool or implement and elevate the locking-pins i out of engagement with the notched upper ends of the pawls h, and also remove the plates 1 and raise the pins 11, which hold the bolts K in fixed engagement with the rack-bars.

By the means hereinbefore described it will be observed that when the hoisting-rope breaks the cage is not only held against a downward movement, but also against an upward movement.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In combination with an elevator-cage having a hoisting-rope and a safety-rope, for the purpose set forth, a Windlass consisting of a drum fixed to the shaft thereof, over which the hoisting-rope passes, and a drum, over which the safety-cord passes, loosely mounted on the shaft and held infrictional contact with the hoisting-drum, substantially as set forth.

2. The combination, in a hoisting device for elevators, having a hoistingrope and safety-rope for operating safetycatches attached to the cage, of a driven shaft having rigidly fixed thereto a drum over which the hoisting-rope passes, said drum havinga frictional clutch-face, a drum loosely mounted on said shaft and having a corresponding clutch-face, a spring for holding the movable drum in contact with the fixed drum, and means for regulating the frictional contact of the drums with each other, substantially as set forth.

3. Thecombination, in an elevator, of a car or cage having a cross-bar E, movably secured thereto, to which are rigidly attached depending bars F, said depending bars havin g inwardly-proj ecting pins, the vertical side pieces of the cage carrying safety-catches adj acent to said inwardly-proj ecting pins, which are adapted to be thrown outwardly for en-' gagement with rack-bars a when the crossbar E is moved toward the top of the cage, substantially as set forth.

l. The combination, in an elevator, of a cage having a movable cross-bar E, depending bars secured thereto and connected with the cage, a hoisting -rope attached. to the main frame of the cage and a safety-rope connected to the cross-bar E, means for con necting the depending bars F with springretracted bolts, and automatic locking devices for holding the bolts projected and in engagement wit-h the rack-bars e 6 when said bolts have been projected,substantiallyas set forth.

5. The combination, in an elevator, of a cage having a hoisting-rope and a safetyrope, a cross-bar E, having vertically-depending bars connected movably to the cage, said bars being provided with inwardly-projecting pins, spring-retracted bolts K, connected to the depending bars, safety-catches h h, carried by the cage, and automatic locking-pins 21 and i for holding the catches and bolts projected when the depending bars are elevated, substantially as shown, and for the purpose set forth.

6. In combination with an elevator-cage having movable side bars F, adapted to be operated by a safety-cord O in the manner set forth, of safety-catches h, having a curved side, with which pins f carried by the bars F, engage, so as to retract the catches h when the pins f lie below the pivots thereof and project the same when moved above the pivot, substantially as set forth.

7. The combination, with an elevator-cage,

the pin f carried by the sliding bar F, substantially as set forth.

8. The combination, in an elevator, of a Windlass constructed substantially as shown and provided with a hoisting-drum and a drum over which the safety-cord passes, said drums being held in frictional contact with each other, the safety-cord being attached to the movable bar E within the elevator-cage, said bar having depending bars F F, to which springs are attached, said springs serving to hold the cross-bar E against the pull or strain of the friction-drum, together with safetycatches constructed substantially as shown,

. bars, said pins contacting with the safetycatches, so as to project the same when the bars F are elevated and retract the same when lowered, said safety-catches being adapted to engage with rack-bars, the bars F being automatically held so that the projecting pins carried thereby will lie below the pivot of the safety-catches, for the purpose set forth.

10. The combination, in a cage for elevators, of vertically-movable bars F, secured to the cage, a safety-rope connected to said bars,

a spring for holding said bars normally depressed, the cage being provided with safetyeatches h, sliding bolts K, flexible connections m, connecting the bolts with the de' pending bars, and independent automatic locking mechanism operating simultaneously 40 upon the locking-bolts and safety-catches to hold them in engagement with the rack-bars of the elevator-shaft, substantially as shown, and for the purpose set forth.

11. The combinatiomwith an elevator-cage, of spring-retracted bolts K, vertically-movable bars F, connected to a safety-rope, flexible connections N, attached to the safetybolts and to the bars F, and locking-pins 2: and removable plates 1 let into the floor of the cage, substantially as set forth.

In testimony whereof I aiiix my signature in presence of two witnesses.

JOHN K. JOHNSON. Witnesses:

E. W. JOHNSON, H. L. BEALL.