US597245A - Screen - Google Patents

Description

3 SheetsSheet 1.

(Nu Model.)

D. E. PHILLIPS. SGREBN.

Patented Jan. 11, 1898.

3 Sheets$heet 2.

(No Model.)

1). E. PHILLIPS. SCREEN. No. 597,245.

Patented Jan. 11, 1898.

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DAVID E. PHILLIPS, OF MAHANOY CITY, PENNSYLVANIA.

SCREEN.

SPECIFICATION forming part of Letters Patent No. 597,245, dated January 11, 1898.

Application filed February '7, 1 895. Serial Nor 537,554. (No model.)

To all whom it may concern.-

Be it known that I, DAVID E. PHILLIPS, a citizen of the United States, residing at Mahanoy City, in the county of Schuylkill and State of Pennsylvania, have invented certain new and useful Improvements in Screens; 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.

Woven-wire screens are peculiarly elfective in the coal regions for screening coal for the reason that by the irregular surface made by the interweaving of the wires to form the mesh the coal. is effectively retarded, agitated, and tumbled to lift the larger lumps of coal and agitate the mass so that the smaller sizes, as well as the dust or culm, can work toward the screening-surface and there be screened. Wire screens are objectionable, however, on account of their comparatively short life of usefulness, owing to the fact that the wires composing the mesh will be moved one on another by the action and pressure of the coal, to thus disturb or destroy the regularity of the mesh, whereby imperfect screening and sorting of the coal is the result. This objection is more serious in cases where mine-water is used in connection with coal-screens to facilitate the separation and screening of the coal, because the water rapidly corrodes the wires and hastens their tendency to slip on one an other under the action of the coal. Castmetal screens have been and are'still used to avoid this serious objection incident to the use of wire screens; but cast-1n etal screens are objectionable because of their great weight, the extra power required to run the screen apparatus when equipped with them, the frequent breakage in use, and of their deficient screening capacity owing to the large amount of metal comprising the web or walls and the comparatively small number of interstices.

Punched-plate screens are becoming widely used as substitutes for woven-wire and cast- .metal screens, because they are not open to or tumbled. To overcome this feature, such screens have been provided with tumblers or agitators and the surface of the screens has been roughened or corrugated. In some forms of roughened or corrugated punchedplate screens known to me the construction has been such as to be objectionable on account of breaking or chipping the coal to lessen the size of the lumps to produce more of the finer or less desirable sizes of coal and to increase the amount of dust or culm. This has been brought about by disposing the corrugations or roughened parts with relation to the working surface of the screen so that in the revolution of the screen such roughened or corrugated portions would act, in a substantial sense, as so many chisels or sharp projections to bite or chip and break the coal. My present invention has for its object to overcome these objections and to provide a punched-plate screen which shall have in use substantially the beneficial qualities of the woven-wire screen to thoroughly agitate, tumble, and screen the coal; and to this end my invention is fully set forth in the following description and particularly pointed out in the claims.

Figure 1 is a perspective view of my improved punched-plate screen,.which constitutes a section or segment of a screen appa-. ratus. Fig. 2 is a longitudinal section on the line 2 2 of Fig. 1. Fig. 3 is a transverse section on the line 3 3 thereof. Fig. 4 is a perspective view of a modification, and Fig. 5 is a cross-section on the line 5 5 of Fig. 4. Fig. 6 is a perspective view of still another modification, and Fig. 7 is a cross-section on the line '7 7 of Fig. 6.

Referring to the drawings, the one-piece punched-plate metal screen or segment is shown as a whole in perspective in Fig. 1, wherein the working surface, or that brought in contact with the coal, is in this instance shown uppermost, with the screen bent or curved as a whole to enable it to be fitted to the rings of a revoluble screen apparatus, although, when desired, the screen may be made fiat, as when used in shakers, as shown in Figs. 6 and 7.

The imperforate margin (which I term, for convenience, the rim 0.) incloses the web portion and interstices, the said web portion consisting of a number of transverse webbars I) and longitudinal web-bars c, cons tituting the walls surrounding the interstices d. It will be observed that in the present instance the transverse web-bars b, as well as the longitudinal web-bars c, are bent or concaved with relation to the uppermostor workin g face of the screen, leaving the part c, constituting the junction of the transverse webbars b with the longitudinal web-bars a, relatively raised abovethe concaved transverse and longitudinal web-bars and disposed sub-, stantially in the plane of the screen as a whole. By this construction I get a maximum of interstices, and hence increased screening power, while the disposition of the web-bars with relation to the parts 6 preserves uniformity of interstice and enables the screen to efficiently retard, agitate, and tumble the coal to get screening, separation, and proper sizing of coal.

It will "be observed also that such a construction does not when in use, present to the coal sharp chisel-like edges or projections to chip and break the coal'in the revolution of a screen apparatus equipped with my improved screen.

It-would be no departure from the-spirit of my invention were thescreenshown in Fig. 1, which presents the working face to the eye, bentas a whole in an opposite direction and that which in Fig. 1 is the back constituted the working face, which modification is shown in Fig. 4:, in which event the transverse and longitudinal web-bars b would be bent or convexed with relation tothe working face, while the parts .6 would be depressed relatively to the web-bars while being disposed, as inFig. 1, substantially in the plane of the screen considered as a whole.

In all of the several forms of my inventionthat shown in Fig. 1, which may be designated the concave form, that which is shown in Fig. 4 and which may be designated the convex form, and that wherein the plate is fiatthe crimped, corrugated, or bentlongitudinal and transverse web-bars constitute a series of undulations, all of which are arranged on one andthe same side or face of theplate, the nodes or intersections of these crossing waves being in substantially the plane of the body orrim of the plate. It is by these peculiarities of construction I am enabled to obtain the beneficial results sought and to avoid the objections incident to the hereinbefore-recited prior constructions.

By my construction the segment has an in creased wearing capacity and at the same time will cause a minimum of breakagean'd consequentwaste of coal. For instance, referring to the construction shown in Fig. 1, it is manifest that by having thetransverse andlongitudinal web-bars depressed and-the nodes or apexes disposed in the planeof the plate the web-bars are protected from undue wear from the friction of the mass of coalwhich passes through the screen, while .the

wear is mainly received by said nodes-the strongest part of the mesh of the segment. Further,: by any disposition of the 1 web-bars and nodes to gettumbling effect and wearing qualities the mesh or orifices are more uniform in size than with other forms of roughened or crimped plate wherein some of the web water and the'frict-ion of the mass of coal passing over the segments, and that as soon as a segment'isworn out in part it must be discarded asa whole, and considerlngthe frangible nature of coal and the importance of :preventing waste or deterioration from breakage, (because, as is well known, large- -sized coal is morevaluable than small,) my improved construction contributes toward perfection in a segment for use in coal-screens in three important particulars-i-namely,first,

lessened breakage of coal; second, more uniform sizing. of the coal, and, third, Increased wearingcapacity.

.As to lasting qualities, and referring again to the construction illustrated in Figs. 1, 2,

and 3, which I believe to be the best, it is important to have the nodes or apexes in the plane of the body of the plate for two reasons: first, if the apexes were raised "above the plane of the plate the first row next to the imperferate edgeportion wouldreceive the greatest wear fromthe oncoming mass of coal, owing to the fact. that theywould stand. above the plain imperforate edge, and hence wouldwea-r out much more quickly than the remaining rows of nodes, thus requiring the segment to be discarded as a Worn segment at a time when by far the greater part of the segment had received but little wearg second, the web- -bars next to the imperforate edgeswould necessarily be'without the'desirable outward curve, since the raising of the apexes would take up allthe tension in'the metal.

While I believe that the form of constructionshown in Figs. t and has not the wearing qualities of thatshown in :Figs. 1, 2, and 3,-yet it is a desirable construction in lessening the breakage and: consequent .waste of coal, in its uniformity of mesh and size of openings to properly size thecoal, initsuniformity of tumblingoragitating action on the coal, and

in its capacity for wear.

WVhat I claim is- -1'. As an improved article of manufacture, a punched metal screen-plate, having a series of interstices bounded longitudinally and transversely by integral :web-bars, each of which web-bars has an und ulatory formation, the. troughs of the undulations extending in one; and the same direction, and the crests or apexes standing substantially in the plane of the body of the plate, whereby uniform and stable interstices are secured, and the material being screened is efficiently retarded, agitated and tumbled in order to etfectthe screening, separation and proper sizing of such ma terial, substantially as described.

2.' As an improved article of manufacture, a punched metal screen-plate, having a series of interstices bounded longitudinally and transversely by integral Web-bars, each of which web-bars has an undulatory formation, the troughs of the undulations extending in one and the same direction and being disposed below the plane of the body of the plate, and the crests or apexes standing substantially in the plane of the body of the plate, so that all of the Web-bars are, substantially, below the plane of the body of the plate with relation to its Working face or surface, whereby uni- DAVID E, PHILLIPS.

Witnesses:

JOHN D. MrssWoN, JAMES H. LANGE.

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