US819140A - Hoisting apparatus. - Google Patents

Description

No. 819,140. PATBNTBD MAY l, 1906. W. F. HUNT a R. J. ROBERTS.

HOISTING APPARATUS."

APPLIGATION FILED JAN. 2o, 1905.

Unirse srnfrns Parana? ernten.

WILLlAM F. HUNT ND ROBERT JEFFRIES RQBERTS, OF NEW YORKJN. Y.

HolsTlNe APPARATUS.

Specification of Letters Patent.

atenten May 1, 1906.'

Application filed January 20,1905. Serial No. 241,915.

Z'o all whom, it may concern:

Be it known that we, NiLLIAM F. HUNT and ROBERT Jnrrnrns ROBERTS, citizens of the United States, residing in Vest New Brighton, in the borou h of lichmond, of the city of NewYork, in t 1e State of New York, have invented certain new and useful Improvements in Hoisting Apparatus, of which the following is a specification, reference being had to the accompanying drawings, forming a part hereof.

This invention relates to hoisting apparatus of the general character of that commonly employed for discharging coal and other like urposes in which two drums are provided ihr winding and unwinding the ropes which raise and lower and also control the opening and closing of the shovel or scoop. Such hoisting apparatus is commonly driven by a steam-engine and is controlled by three levers7 one, usually a foot-lever, controlling the throttle of the steam-engine, and the other two controlling the friction-clutches through which the two drums are driven from the engine. The desirability of substituting electricity as the motive power in many installations of this character 1s obvious; but it has thus far proved impracticable for most installations because of the great cost of installing an efficient motor control by which it shall be ossible to vary the power of the motor, as t e power of the steam-engine is controlled b throttling, so that theload may be starte slowly and its movement controlled as desired. It is impracticable to rely simply upon the usual riction-clutehes for the two drums because of the excessive heating which would be developed7 the motor running continuously.

It is the object of the present invention to render practicable the application of the continuous v-operating motor, such as an electric motor, to the operation of such hoisting apparatus while avoiding the difliculties and objections above referred to and without requiringT further increase in the number of controlling-levers. It is undesirable to increase the number of, controlling-levers, for the reason that three 'levers are all that can be properly managed by one operator.

1n accordance with the invention each hoisting-drum is driventhrough its own friction-clutch or equivalent variable driving means from the transmission mechanism, and between the transmission mechanism and the motor is a third friction-clutch or equivj alent variable driving means. By the interposition in this manner of two friction- Y clutches between the motor and each drum it is possible to divide the total slip between the two friction-clutches so that the amount of heating in either clutch is not excessive. The use of a friction-clutch between the motor and the transmission mechanism, however, deprives the apparatus of the= resistance which is offered by the steam-engine in a steam-driven apparatus for purposes of braking when the drums are stationary or are permitted to rotate in a reverse direction, since the friction-clutch between the motor and the transmission mechanism must be wholly disconnected at such times. As already stated, it is impracticable to add a separate brake for the transmission mechanism to be controlled by the operator, and it therefore becomes necessary to give the transmission mechanism such a character that it will automatically resist backward movement. Obviously this may be accomplished by different means, one convenient form of such means being represented in the accompanying drawings, in which a practical embodiment of the invention is illustrated for purposes of explanation of the nature thereof.

ln the drawings, Figure l is a view, partly in plan and partly in horizontal section, of a hoisting apparatus which embodies the in-l vention. Fig. 2 is a side elevation of the same.

ln the en'lbodiment of the invention which is illustrated in the drawings the two drums a and I), having the hoisting-ropes wound about them, are represented as mounted loosely upon a common shaft c. The latter is shown as supporting also a worm-wheel (l, which may have secured thereto or formed therewith two friction-clutch members d and d2, which coperate, respectively, with the corresponding clutch members a and b' ol' the drums (L and b. Each drum isadapted to be moved into or out of engagement with the common gear through the frictionclutch by a controlling-lever e, acting through a rock-shaftf, a system ol' links and levers g, and screws 11, as usual in hoisting apparatus of the character to which the iuvention relates.

The two friction-clutches or other variable driving means for the two drums are driven by a transmitting mechanism which comprises in the embodiment ol the invention illustrated the worm-wheel d above mentioned IIO and a worm i upon a shaft 7c, these parts constituting a convenient form of transmitting mechanism which is non reversible in the sense that it resists backward movement from the load. The shaft 7c carries one member Z of a friction-clutch or other variable driving means, the other member 'm of which vis keyed upon the shaft n, driven by the niotor or source of power o through a reducinggear fp. The movable clutch member, which in this insta-nce is shown as the member ym., is represented'as controlled through a lever g from a foot-lever r, which is convenientlyv placed with relation to the hand-levers e, so that one operator can control all three of the clutches as the conditions ot' operation may require. Y

ln the operation of the apparatus, it being understood that the motor o is running continuouslv, the operator, pressing upon the lever i, throws in the clutch Z m, and imparts motion to the transmitting mechanism. Then by operation of Ythe levers c one or the other, or both, of the drums (L and l) are made to rotate at speeds which are determined by the engagement of the clutches a. d and o Abt. it itis desired to stop the movement of the shovel, the clutch l Imis opened and both clutches a d and lf2 are closed, the resistance necessary to hold the drums a. and b from rotation under the tension of the load being furnished by the transmitting mechanism which, as previously indicated, is ol such a character as to prevent movement in a. re verse direction. Such unwinding ol either or both hoisting-ropes as may be necessary is permitted by releasing'one or the other, or both, of the drum-clutches, and it will be obvious that b y proper manipulation oi' the clutches anv desired'movement ma)r be imparted to the shovel. l `urtbermore, as already pointed out, the motor may be allowed to rotate continuously, no undue heating of an)v clutch is necessarily occasioned under any conditions o1C operation, and the whole apparatus is under the control oi a single operator through three controllinglevers. l

it will be obvious that various changes can be made in details ol' construction and arrangement without departing from the spirit of the invention.

We claim as our invention-n 1. 'lhe combinatiomin a hoisting apparai I l 1 tus, of a source of power, two hoisting-drums, independent variable driving means interposed between the source of power and the drums respectively whereby either of said drums may be driven independently of the other, a third `variable driving means interposed between the source of power and the iirst named variable driving means, and means for preventing the reverse rotation of the Yfirst-named variable driving means, substantially as described.

2. The combination, in a hoisting apparatus, of a source of power, two hoistingdrums, independent clutches interposed between the' source oi 4power and the drums respectively whereby either of said drums may be driven independently of the other, a third clutch interposed between the s ource of power and the vfirst e named clutches, and means for preventing the reverse rotation ot the tiret-named clutches, substantially as described.

3. A hoisting apparatus comprising two drums, a non-reversible transmitting mechanism, clutches interposed between the drums and the transmitting mechanism, a motor, a clutch interposed between the motor and the transniitting mechanism, and means to control said clutch, substantially as described.

el.. A lmisting apparatus comprising two drums, a non-reversible transmitting mechanism having a gear common to both drums, clutches interposed between said gear and said drums, a motor, a clutch interposed between said motor and the transmitting niechanism and means to controlsaid clutches, substantially as'described.

5. A hoisting apparatus comprising two drums, a worm-gear common te both drums, independent clutches interposed between said gear and said drums whereby either of said drums mayr be driven independently of the other, a worm-shaft, a motor, a clutch interposed between the said motor and the worm shaft and means to control said clutches, substantiall)T as described.

This specification signed and witnessed this 'lth day oidanuary, A. D. 1904.

wu. r, HUNT. ROBERT JEFFHHS ROBERTS. ln presence of* W. B. Generar, M. A. BRAYLEY.

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