US573904A - John a - Google Patents

Description

(No Model.)

J. A. MGGREGOR.

HUISTING MAUHINB.

Patented 1360.29, 1896.

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UNITED STATES ATENT OFFICE.

JOHN A. MCGREGOR, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE EDWIN I-IARRINGTON, SON ab COMPANY, INCORPORATED, OFV

SAME PLACE.

HolsTINc-MACHINE.

SPECIFICATION forming part of Letters Patent No. 573,904, dated December 29, 1896.. Application filed December l, 1893. Serial No. 492,427. (No model.)

To all whom, t may concern:

Be it known that I, JOHN A. MCGEEGOR, of the city and county of Philadelphia and State of Pennsylvania, have invented an Improvement in Hoisting-Machines, of which the following is a specification.

My inventionfrelates to hoisting-machin es; and it consists of certain improvements which are fully set forth in the following specification and shown in the accompanying drawings, which form a part thereof.

My invention comprehends certain improvements in so constructing the hoist that a different degree of friction may be created to increase or decrease the tendency of the hoist to run down. vThese various improvements will be better understood by reference to the accompanying drawings, in which- Figure l is a side sectional elevation of my improved hoisting-machine, and Fig. 2 is a transverse section of same.

Ais the main frame and has j ournaled within it a transverse shaft B, having secured or formed integral thereon theWorm-wheel O,

which is preferably inclosed within the case A.

D is a worm meshing with the worm-Wheel O and is secured to or formed integral with the shaft E, which is journaled within the frame A at right angles to the shaft B and contains upon its outer or free end a handchain wheel K, the chain of whicht is adapted to be operated by hand in the usual inanner in operating the hoist and is guided through suitable guides K', secured to the frame A. The rear bearing of the shaft E is enlarged, as at c, so that if permitted to work against the face F of the frame A it will create a considerable friction owing to the large surface contact. When but asmall frictional contact is required, such as in cases where it is desired to make the lifting or power chain L with its lifting-hook run down freely, a

small bearing G, carried in the frame A, may be forced forward by means of a screw H, so as to push the bearing G away from the rear face F, as -indicated in Fig. l, and thereby reduce the extent of surface in frictional contact. The screw I-I may be providedwith a chain-wheel I, over which a light handchain wheel J may pass, so as to be able to change the frictional contact when the hoist is in an elevated position. To enable the part c to come into contact with the face or bearing F, clearance must be provided to permit the shaft E to move longitudinally in its bearing. The tendency of the worm D Vworking in the worm-wheel O is to force the shaft E backward against its thrust-bearing, and it is therefore evident that by varying the extent of frictional contact its thrustbearing may prevent to the desired degree the weight of the lifting-chain L and its hook, causing the machine to run down. It is also evident that under such conditions the hoist may be brought into such adjustment that a very slight movement of the hand-chain 7a will cause the machine to run down fast or Slowly.

M M are two lifting-chain wheels over which thelift-chains L L pass and are provided with square or substantially square holes, as at m, which fit upon square or substantially square ends b of the shaft B, carrying the worm- Wheel O. The shaft B is provided With shoulders adjacent to the frame A, between which and the outer washers r the chain-wheels M are clamped through the agency of a transverse bolt R. In this manner the chainwheels are easily attached to the shaft B1 and yet are readily removed for repairs, and no amount of weight upon the chain L can turn the said chain-wheels M upon the said shaft B. There should be no material frictional contact between the bearing A of the frame A and the chain wheels M, but the said wheels should be carried upon the shaft B in such a manner as to prevent any possibility of the turning independently of the shaft.

The hoist as an entirety may be suspended by means of a hook O, pivoted to a frame P, secured to the frame A by being sleeved upon its bearings A concentrically with the `hollow transverse shaft B.

While I prefer the construction shown, I do not limit myself to the minor details thereof, as they may be modified without departing from the principles of my invention.`

VVhatI claim as new,'and desire to secure by Letters Patent, is

In a hoisting-machine, the combination of the :main frame formed with a bearing-socket F of enlarged diameter adjacent to the thrust IOO end of the Worm-shaft, a Worin-shaft journaled in said frame and having a journal e of enlarged diameter journaled in the enlarged bearing-sooket F and free to be moved longitudinally therein so as to bring the faee of the journal e of enlarged diameter into frietional Contact With the face of the bearing-socket., or to he moved out of Contact therewith, and an adj usting-sorew H passing through the end of the socket and hearing on the face of the journal e, for moving the Worm-shaft and causing the face of the journal to make frietional Contact With the face of the` socket, or not to make Contact there- With, whereby a slow or despatch movement may be imparted to the hoist by the resulting application or removal of friet-ion to the Worin-shaft..

In testimony of which invention I have hereunto set my hand.

' JOHN A. MCGREGOR. Vitnesses:

ERNEST HOWARD HUNTER, HELEN L. MOTHERWELL.

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