US138655A - Improvement in hoisting apparatus - Google Patents

Description

l. L. ISBELL.

Hoisting Apparatus.

Patented May 6 AM PHorwumosMPH/c ca Mx (Mean/v53 mabsssg) UNITED STATES JOHN L. ISBELL, or NAUGATUOK, CONNECTICUT.

PATENT O IMPROVEMENT IN HOISTING APPARATUS.

Specification forming part of Letters Patent No. 138,655, dated May 6, 1873; appll tion filed April 16,1873. 1

To all whom it may concern:

Be it known that I, JOHN L. IsBELL, of Naugatuck, in the county of New Haven and State of Connecticut, have invented a new Improvement in Hoisting Apparatus; and I do hereby declare the following, when taken in connection with the accompanying drawing and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawing constitutes part of this specification, and represents, in-

Figure 1, a top View; Fig. 2, a front view with a-portion of the frame broken away; and in Fig. 3, a transverse section through the pulleys on line a w.

This invention relates to an improvement in hoisting apparatus, the object being such a construction as will automatically prevent the running down of the fall in case of accident; and the invention consists in a drum carrying the fall, combined with a drivingshaft provided with means for communicating power thereto in opposite directions, and with intermediate gearing between the said shaft and drum, whereby power is communicated to the drum to raise or lower the fall, the gearing which lowers the fall being a worm and each of said gearings proportioned for equal velocity, and a slight amount of lost motion provided on one chain of gearing, all as more fully hereinafter described. I

A is the framework which supports the mechanism. B is the drum, arranged upon a shaft, 0, and supported in suitable bearings. Upon this drum the fall D is secured, so that, by turning the drum in one direction, the fall is wound thereon, and in the other direction the fall is run ofi, in substantially the usual manner. E is the driving-shaft,preferably arranged transversely to the shaft 0, and is supported in bearings F. Upon this shaft are two pairs of pulleys, G G and H H, one of each pair, G and H, being loose pulleys. The pulley H is securely attached to the shaft. The pulley G is attached to a sleeve, 9, through which the shaft runs, but so as to leave the pulley and the sleeve loose upon the shaft. In this sleeve is a slot, h, and in the shaft is a stud, 6, extending into this slot, so that the said pulley, in turning, will engage the shaft, but allow a lost motion to the extent of the slot h, for the purpose more fu y hereinafter described. Upon the driving-j aft a pinion, I, works intoa pinion, I 0 a transverse shaft, 1 connecting to the dru l by a pinion,

I and gear 1. Power applie to the pulley G will, through this chain of caring, cause the drum to revolve in the dir -tion to wind up the fall, such direction bei 1 denoted by the arrow in Fig. 2. On the dri ng-shaft over the shaft 0 a worm, L, is arran f to work into a wormgear, L. 1 1

Power is applied to the pull y H to cause the worm to rotate the drum i the opposite direction to the first-describe gearing, the rotation of the shaft E being; eversed, the worm being used for the lowerin of the weight. The proportion of the worm a i the pinion I to their respective gearing is th same, so that if both sets of pulleys are firm I attached to the shaft both chains of gearing ill be turned by means of either pulley. Tha such may not be the result, and that one ma 1 always be a little in advance of the other, f the purpose of the lost motion provided for; 1y the slot h.

It will be understood that th: 1 power is applied to but one of the pulleyat the same time, and that when the fixed i ulley of one pair is at work the belt will be on the loose pulley of the other; hence, whe power is applied to the pulley G to raise t e weight the lost motion gives it a little a vance of the worm and allows the worm to W rk freely and without effect upon its wheel L 1 nd when the power is shifted to the pulley 3 the lost motion in the pulley G allows the ornl to run a little in advance, causing it to 01 rate through its wheel L. 1

When the power is working t 1 on gh the pulley G to raise the weight, sho d the power bBCOlllB disconnected, or similz accident occur, which would give the fall 1 I tendency to run down, the power of the fa is brought, through the wheel L, directly n 4 a the worm; and, as that power cannot cause e revolution of the worm, it follows that the; escent is immediately arrested and the co sequences of such an accident prevented, an in like manner serves as a brake to hold t load at any point. I have represented the poet through the pulleys, but it wil r as applied e rcadily un- 2 neexsso derstood that other known and equivalent through which power is communicated in one means may be employed for communicating power to the shaft E.

I claim as my invention- In combination with the drum B, the two runs or chains of gearing, one of which causes the revolution of the drum to wind or raise the fall, the other the revolution of the drum in the opposite direction to lower the fall, the latter by means of it worm, L when the device direction is constructed to allow a slight overmotion independent of the other device for communicating power in the opposite direction, substantially as set forth.

J OHN L. ISBELL.

Witnesses:

J oHN E. EARLE, A. J. TIBBITS.

Images