USRE6211E - Improvement in coal screens and chutes - Google Patents

Description

BEST AVAILABLE COPY M. R. ROBERTS.

Coal Screens and Chutes.

Reissuedlan.5,1875.

UNITED STATES PATENT ()rrrcm MARTIN R. ROBERTS, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN COAL SCREENS AND CHUTES.

Specification forming part of Letters Patent No. 140,077, dated June 17, 1873; reissue No. 6,211, dated January 5, 12-575; application filed August 4, 1873.

To all whom it may concern:

Be it known that I, MARTIN It. ROBERTS, of San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in a 00mbined Portable Hopper, Uhute, and Screening Apparatus; and I do hereby declare that the following is a full, clear, and exact description thereof, that will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

In the apparatus at present used for unloading ships the coal ishoisted in a tub, by ropes and tackle, high enough above the decks to pass clear of the bnlwarks in swinging out over the wharf, and is poured from the elevated tub, and falls a distance of from ten to thirty feet upon the wharf, or upon the pile of coal already dumped thereon.

In this operation the coal is damaged by being broken in falling from thetub, and in breaking the already dumped coal on which it falls.

The coarse coal and screenings or fine coal are all in the dump together, unassorted, and have to be shoveled from the wharf into vehicles for removal to the coal-yards, where it has to be again shoveled over one or more times in screening. Each time the coal is thus handled its cost is increased by the expense of the labor required to do the hand ling, and at the same time the coal is injured by being, to a greater or less extent, broken and pulverized.

The object of my invention is to save expense in the unloading of coal from watercraft, and in screening and in reloading the same into vehicles for further transportation; to accomplish these results with greater dispatch and convenience than is now done, and to prevent as far as possible the breaking and pulverizing of the' coal in unloading, reloading, and screening it.

My invention consists of a portable framework, supporting a hopper, reservoir, chute, and screening apparatus, especially adapted to the accomplishment of the object above stated.

In order to more fully illustrate and explain my invention,'reterence is had to the accompanying drawing, forming a part of this specification, in which A A represent a strong frame, which is properly stayed and braced, so as to withstand the concussions to which it will be subjected. At one side of the top of this frame I secure two boards, B B, at an obtuse angle to each other, in the form of a trough, but leave their lower ends separated, so as to provide a space, 0, between them, for the purpose hereinafter described. These boards form what I call the hopper. The board B forms an extension to one side, D, of a large reservoir, 0, which is located in the body of the frame below the hopper. This side D of the large rcservoir slopes toward the opposite side of the frame, and is constructed of parallel wires secured at short distances apart, so as to form a screen over which the coal or other substance must pass in descending from the hopper to the reservoir, and through which the small particles, up to a certain size, will fall, leaving the larger pieces, which cannot pass through the screen, lying in the second or large hopper. The reservoir is contracted toward its lower end, and a chute, F, extends from it out over the opposite side of the frame from that on which the upper hopper is located. A gate, h, which will be more fully described hereafter, serves to retain the coal in the chute and reservoir until it is desired to allow it to pass from-the chute into a cart or other vehicle. An independent grate or screen, I, of finer mesh than the grate D, is secured in an inclined position in the frame A A below the screen D, so asto receive the particles of coal or other substance which pass through the upper screen, and which serves to again separate it into two grades. This screen stands at an angle transversely to the upper screen, so that the particles which pass down it on account of not being small enough to pass through the meshes will be carried off to one side of the machine, while the finer portions which pass through the screen will fall upon the floor or wharf directly under the frame. Two or moreof these screens can housed, and the size of the meshes can be varied according to the substance to be cleaned, and the numher and quality of the grades into which it is desired to separate the substance being discharged.

The frame A A will be mounted upon small wheels, so that it can be moved from one place to another upon a wharf, in order to be placed in position to receive the discharging cargo of different ships; but when moving it from one wharf to another, I employ axles across each end of the frame, upon which strong wheels are placed, so that the entire machine can be drawn along similar to any wheeled vehicle.

The hopper B B is as long as the machine, and is made wide, so that when ordinary care is used in dumping, it is certain to catch all the coal poured from the swinging tub. This hopper is also placed high on the machine, and but slightly above the inclined side of the reservoir, so that the coal has but a short distance to fall, and is thereby prevented from being broken and pulverized. The outlet of the hopper B B extends entirely across the upper.

end of the side or screen D, by which arrangement the passing coal is distributed over the entire width of D, and has to pass its entire length, thus insuring a thorough screening of the coal. The construction and location of this hopper B B makes it a success in receiving the contents of a tub swung from a yard-ar|n, a result which I believe was never before accomplished by any hopper.

By placing the reservoir 0 in its peculiar position and making it large, several advantages are obtained. Among others, a large screening-surface is obtained; the gate his sufliciently high from the wharf to allow vehicles to be driven under it and receive the coal direct as it is discharged from the chute, so as to save reloading it from the wharf; and the reservoir 0 is large enough to serve as a storeroom, so that in case of temporary delay in the vehicles carrying the coal to the yards, the work of unloading the ship or other vessel can proceed without the necessity of piling the coal upon the wharf.

When it is not desiredto screen the article or substance to be unloaded, a false bottom or metal blank, K, is placed upon the grating or inclined side D of the reservoir, so that the substance will be carried directly through the chute into the cart or wagon intended to convey it away.

The gate or cut-0E which I use consists of a lever-bar, p, which has one end pivoted to the frame, so that it will extend transversely across above the end of the chute. Metal teeth h extend downward across the mouth of the chute, so as to bar the entrance. 'hen the cart is in position beneath the chute, the free end of the lever is raised so as to clear the teeth from the mouth of the chute, and allow the substance to pass through by its gravity into the cart.

From the practical success which has attended my invention, I believe its introduction will make it profitable to ship other substances, such as cobble-stones, gravel, 850., and assort them while unloading the ship.

By this arrangement coal can be discharged from ships, screened, and loaded into cart-s, not only at a great saving of expense in handlingit, but with less wastage, as the large and more marketable pieces or lumps will not be broken when dumped in this machine, as they always are to a greater or less extent when dumped from the height of twenty or thirty feet upon the wharf or coal-pile.

Having thus described my invention, what I claim, and desire to secure by Letters Pat, cut, is-- 1. The receiving-hopper B B, in combination with the reservoir 0, with its screen or grating side D, chute F, with its toothed gate h, and one or more independent screens, I, all combined and arranged substantially as and for the purpose above described.

2. The metal blank or false bottom K, in combination with the receiving-hopper B B, reservoir 0, chute F, and gate h, substantially as and for the purpose above described.

3. The combination of the hopper B B, for receiving the coal from a swinging bucket, the reservoir 0, arranged to receive the coal as it passes from the hopper, with the chute F and gate It, all constructed to operate substantially as and for the purpose set forth.

4. In combination with the elongated hopper, the screen D,reserv0ir O, and chute F, with its gate 11., the combination being substantially such as is herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand and seal this 2lth day of July, 1873.

MARTIN RICHARD nonnnrs. lL. s]

Witnesses:

P. O. WVEGENER, JOHN L. BooNE.

Images