US1278792A - Scaffold-lift. - Google Patents

Description

L. S. TOWNSEND. SCAFFOLD LIFT. APPLICATION FI'LED JULY .12. 1918. 1,278,792., Patented Sept. 10,1918.

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TOLEDO, OHIO.

SCAFFOLD-LIFT.

Application filed July 12, 1918.

To all whom it may concern:

Be it known that I, LEROY S. TOWNSEND,

a citizen of the United States, and a resi.

dent of Toledo, in the county of Lucas and State of Ohio, have invented a certain new and useful Scaffold-Lift; 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 appertains to make and use the same, referencebeing had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to lifts, and particularly to a device of this character for use in connection with scaffolds to raise and lower thesame.

The object of my invention is the provision of a simple and improved device of the character described, which is capable of being easily and quickly operated to raise a scaffold or to control the lowering thereof and is capable of being locked in any position of adjustment.

The invention is fully described in the following specification, and while, in its broader aspect, is capable of embodiment in numerous forms, a preferred embodiment thereof is illustrated in the accompanying drawings, in which,

Fi 'urel is aside elevation of an 3,333..

ratus embodying the invention.

Fig. 2 is a different elevation thereof with parts in vertical section and with parts removed", and Fig. 3 is a sectional detail of the control portion of the device.

Referring vto the drawings, 1, designates a frame, which, in the present instance, is of triangular form with its apex disposed upward, and to the bottom of'which frame is centrally secured a sub-frame 2, which extends downward and is intended to be connected in any suitable manner at its lower end to an end of a scaffold to be supported thereby.

A horizontal shaft 8 is mounted in the frame 1 crosswise thereof and fixedly carries a pulley 4;, which is preferably circumferentially grooved to provide a run-way for a cable 5 that is intended to extend around the under side of the pulley. This 'pulley is provided with a plurality of pairs of clutch fingers 6, which are disposed in radial relation to the pulley axis and are Specification of Letters Patent.

Serial No. 244,647. r

the clutch fingers to have swinging movements toward and away from each other. The free ends of the clutchfingers are provided with inward projections or jaws, 8', adapted to oppositely grip a cable extending therebetween on the pulley. The clutch fingers of each set are normally held inspaced or open position by the fingers of a U spring 9 which is mounted in a radial slot or recess 10 in the pulley 4 between the fingers.

During a predetermined portion of a rev? oluble movement of each set of clutch'fin gers, the lower portion, in the present instance, the outer end portions of the fingers pass between arcuatecam members or bars 11, which coact with the free end portions of the clutch fingers as they passtherebetween to grip an interposed oableto prevent a slipping of the same around the pulley 1. The cam bars 11 are secured at their ends to the frame 1 with the adjacent ends of the bars in flaring relation. The centralorwin-w termediate portions of the cam barsare' adjustably connected by bolts 12 to facilitate relative transverse adjustment of the bars to suit-the desired gripping action of the clutch fingers on the cable. It is preferable to have such a number of clutch fingers and length of the bars 11 that more than one pair of clutch fingers will always be in grip ping engagement with a cable on the pulley.

Mounted in the sub-frame 2 below and in parallel relation to the shaft 3 is a shaft 13 which is in driving connection with the shaft 3 through a train of gears 14 of suitable ratio. A crank arm 15 is mounted on an end of the shaft 13 for limited rocking movements relative thereto lengthwise of the shaft, being pivoted to the shaft, as at 16, with its hub end provided with an extension 17 at the side of the shaft opposed to the crank arm. A spring, 18, is fixed to the shaft 13 at the inner side of the hub extension 17 and acts on said extension in a manner to exert an outward force thereon and a consequent inward rocking movement to the crank arm. A ratchet wheel 19 is fixed to the sub-frame 2 at the inner side of the crank arm 15 and has its ratchet teeth 20 Patented Sept. in, 19 118.

under side of the pulley between the clutch fingers 6. The free end of the cable 5 after leaving the pulley 4: passes over a sheave 22 and thence hangs down free therefrom.

In the use of my apparatus the operator who is mounted on the supported scaffold;

turns the crank arm 15 to the left when it is desired to take up the cable 5 and elevate the scaffold, and withdraws the crank arm from engagement with the ratchet wheel and permits a turning thereof to the right under the weight of the load when lowering the scafiold. The engagement of cable 5 by' the clutch fingers of the pulley, prevents a slipping of the cablewith respect to the pulley.

I wish it understood that my invention is not limited to any specific construction arrangement or form of the parts, as it is capable of numerous modifications without departing from the spirit of the claims.

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

1. In an apparatus of the class described, a frame, a cable clutching pulley mounted in said frame, a cable for supporting said frame and having a portion extending under said pulley in engagement therewith, means car-' ried by the frame and cooperating with the pulley to cause it to grip the cable, a shaft mounted ,in said frame and geared to said pulley, a crank arm carried by said shaft,

of said pulley to cooperate with the cablegripping fingers to cause them to have gripping engagement with the portion of the cable extending under the pulley, a crank journaled in said frame, driving connection between said crank and pulley, and means for cooperating with said crank to prevent a back turning thereof.

3. In an apparatus of the class described, a frame, a pair of shafts journaled in said frame a cable clutch pulley carried by one shaft means carried by the frame for cooperating with the pulley to cause itto grip a cable passing there around, driving con: nections between said shafts, a crank arm carried by the other of saidshafts for limited movements lengthwise thereof, a series of ratchet teeth concentric to said crank shaft, and means acting on said crank to normally retain it in ratchet teeth engaging position.

Intestimony whereof I have I hereunto signed my name to this specification.

- LEROY s, TOWNSEND;

Copies 01 this patent may be obtained for live cents each, by addressing the Commissioner ofilatents,

Washington, D. 0.

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