US1198468A - Screen-plate and process of formation. - Google Patents

Description

P. S. MENOUGH. SCREEN PLATE AND PROCESS OF FORMATION.

APPLICATION FILED JAN- 24, H6- 1,1 98,468. Patented Sept. 19, 1916.

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P. S. MENOUGH. SCREEN PLATE AND PROCESS OF FORMATION. APPLICATION FILED MN. 24, I9I6.

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PAUL S. MENQUGE,

VIELLSVILLE, OHIG.

SCREEN-PLATE AND PRGCESE; 3F FGRMATION.

Specification of Letters Patent.

Patented Sept. 19, i lti.

Application filed Eanuary 24, 1918. Serial No. 73,922.

To all whom it may concern Be it known that 1, PAUL S. Mnnooorr, a citizen of the United States of America, and a resident of VVellsville, Ohio, have invented a new and useful Improvement in Screen-Plates and Processes of Formation, which invention is fully set forth in the following specification.

The invention relates particularly to screen-plates of the sort that are used in clay pans, although the invention is not limited to screen-plates adapted for use in such machines.

One object of the invention is to provide a screen-plate, the bars of which are very hard and at the same time very strong and capable of resisting shock.

Another object of the invention is to provide a screen-plate capable of being cheaply constructed without the necessity for expensive patterns such as have heretofore been necessary.

Still another object of the invention is to provide an improved process whereby a screen-plate having the advantages above mentioned can be produced.

Still further objects will be apparent from the following specification and claims.

Referring to the drawings: Figure 1 isa vertical sectional view showing a clay pan and screen-plates therein embodying the invention; Fig. 2 shows in detail one of the bars of which the screen-plates are formed; Fig. 3 shows in detail a mold in which the screen-bars may be cast; Fig. & is a plan view of a screen-plate embodying the inven tion; Fig. 5 is an enlarged sectional view taken along the line 5-5 of Fig. 4:; Fig. 6 is an enlarged sectional view taken along the line 6-6 of Fig. l; and, Fig. 7 is a plan view similar to Fig. l but showing another embodiment of the invention.

In Fig. 1 there is shown a clay pan in order to illustrate one way in which screenplates embodying my invention can be used, but it will be understood that the details of the clay pan itself constitute no part of the present invention. In the clay pan, as illustrated, 1 represents a revolving table carried on the shaft 2 which is rotated by means of the gearing 3 and the drive-shaft l. The central portion of the revolving table is imperforate, being composed of iron plates. Cooperating with these plates are heavy iron mullers 55 which are freely rotatable on a horizontal shaft 6. This shaft is free for vertical movement but is held against bodily movement horizontally. The clay or other material to be crushed or pulverized is introduced between the mullers 5 5 and the iron plates of the table, and after being pulverized moves outward into engagement with screen-plates 77 through which it passes into the receiving chamber below. It is to these screen-plates 77 that my invention particularly relates.

As heretofore constructed, screen-plates for the purpose mentioned have each been formed of a single unitary casting, the slots therein being made by inserting in the pattern small iron chills having the same shape that the slots of-the finished plate are to have. These chills are rammed up in the mold and when the pattern is withdrawn, they remain in the sand in the proper positions to make the desired series of holes or slots in the plate. Usually there are in the neighborhood of two hundred of these small iron chills for each plate. After the casting has cooled the chills are knocked out and re-used. One object of using the iron chills, instead of sand cores, is to quickly cool the iron after casting so as to give the portions thereof adjacent the slots a hard close-grain structure which will resist the wear of the clay.

In accordance with my invention, each screen-plate instead of being a single unitary casting is made up of a plurality of castings in the form of bars; one of these bars being shown in Fig. 2. Each of the bars 8 is cast in a permanent metal mold such as illustrated at 9 in Fig. 3. The permanent metal mold serves to quickly cool the surface portions of the bar after casting, thus giving the said portions a hard white close-grained structure. The metal mold, therefore, serves the same purpose as did the chills, above referred to as having been used in the formation of plates as heretofore made. The mold, however, is much more effective for the reason that it has a larger body of available metal, thus effecting a greater and more sudden cooling. The result is that each of the bars formed in accordance with my invention is extremely hard and, in this respect, much superior to the earlier plates. Preferably as shown in Fig. 2, each of the bars is provided with a fiat top wall and with side walls which are inclined and which meet the top wall to form acute angles. The bottom wall is preferably curved and joins the side walls tangentiallv. It will be seen that with bars constructed in this way the slot between two of them, when they are arranged side b side, will radually incre. se in wid h from top to bottom.

The bars are extremely hard, as has been stated above, and the tendency is for them to be correspondingly brittle. In order to compensate for the tendency of the bars to be brittle, and to enable them to resist bending stresses and shock, I preferably embed in them a reinforcing member 10, of steel or other metal having high tensile strength. Preferably, as shown in F 2, two reinforcing members are provided, one above the other, each member being a cylindrical rod. Theserods are preferably sufiiciently long to project somewhat from the ends of the bar, as shown. Preferably in forming the bar in a permanent mold, such as indicated at 9, the rods 1010 are first inserted in the mold and seated in sockets or apertures l111 provided for them. The mold stands on end as shown in Fig. 3, the rods being vertical. Then the molten metal is poured around the rods and allowed to harden. After that the mold is opened and the casting with the rods embedded therein is taken out in the form shown in Fig. 2. I have found that a compound bar, such as I have shown and described, is not only very hard but also has great strength, the steel rods embedded therein permitting the bar to be bent to a considerable extent without breaking.

In making a complete screen-plate, as shown in Fig. 4, a number of the bars 88 are arranged side by side so as to leave narrow slots between them as shown in Figs. 4 and 6. Preferably, there are two series of bars as shown in Fig. 4%, the bars of one series having their ends in juxtaposition to the ends of those of the other series, and preferably the said juxtaposed ends are staggered or alternated with respect to each other. With the bars arranged as described, there is cast around the ends of them a frame 12 as shown in Fig. 4:. In the preferred embodiment of the invention, the frame 12 has an outer arcuate member which holds the outer ends of the bars of the outer series, an inner arcuate member which holds the inner ends of the bars of the inner series, and a central arcuate member which holds the inner ends of the bars of the outer series and the outer ends of the bars of the inner series, these last said ends being preferably staggered, as heretofore described. Freferably the said three arcuate members of the frame are connected by side radial members.

Preferably, in making a mold for the frame 12, a pattern is used in which the several bars can be mounted and temporarily held. This pattern, with the bars, is rammed up in the sand and the pattern is then withdrawn leaving the bars in the sand properly spaced and positioned. Preferably as indicated in Fig. 5, the arrangement is such that the elements of the frame surround not only the projecting ends of the rods 1010, but also the ends of the bars themselves, but it will be understood to be within the scope of my invention to provide a screen-plate in which the frame elements merely surround the ends of the rods without inclosing the ends of the bars.

It is to be understood that my invention is not limited to the particular arrangement of bars and frame elements shown in Fig. l, as it will be obvious that other arrangements can be used without departing from the spirit of the invention. In Fig. 7,.one such other arrangement is shown, but there are many others. The construction shown in Fig. 7 is similar to that shown in Fig. 4, with the exception that the frame 12 has no central arcuate element, the bars 8 being made long enough to extend from the inner arcuate element to the outer arcuate element.

There are numerous advantages incident to my improved screen-plate and my improved method or process of formation. As has already been stated, the bars are much harder than were any portions of the earlier plates, thus giving my improved plate greater resistance to wear. Because of the presence of the reinforcement in the bars they are very strong and can be made long enough to provide slots extending half of the way, or even all of the way, across the plate. Because of the increased lengths of the slots I am able to provide in a plate of given area a greater total slot length than was possible with the older plan. Gne of the earlier plates of usual size and form had about four hundred linear inches of slots, and one of my improved plates of the same size has about six hundred linear inches of slots. In this way the screening capacity of the plate is greatly increased without increasing its size.

A great variety of shapes and sizes of plates with varying slot arrangements is required to meet the requirements of machines of different makes and to meet different requirements of use. Heretofore, a separate pattern had to be made for each form and size of plate and for each slot arrangement. These patterns were very expensive as they not only had to conform to the main outlines of the plate but had also to be constructed to receive and hold the many small casting iron chills, frequently two hundred in number. In accordance with my invention, it is only necessary to make a pattern for the frame of the plate, this pattern being very simple and cheap.

The arrangement of the slots in the plate and the widths thereof can be varied as desired simply by changing the relative locations of the bars with respect to the pattern for the frame. In this way the expense of making the plates is greatly reduced.

What is claimed is 1. A screen-plate bar formed of hard white chilled cast-iron and having a longitudinal steel reinforcing member embedded therein, the said bar having a broad plane top wall and side walls forming acute angles with the top wall.

2. A screen-plate bar formed of hard white chilled cast-iron and having two parallel longitudinal steel reinforcing rods embedded therein cne above the other and projecting therefrom at their ends, the said bar having a broad plane top wall and side walls forming acute angles with the top wall.

3. A screen-plate bar formed of hard white chilled cast-iron and having a longitudinal steel reinforcing member embedded therein, the said bar having a broad plane top wall, side walls forming acute angles with the top surface and a curved bottom surface.

4.. A screen-plate comprising a series of bars of hard white chilled cast-iron arranged side by side with narrow slots between them, and a frame of softer metal cast around the ends of the bars to support them and hold them in proper spaced relationship.

5. A screen-plate comprising a series of bars of hard white chilled cast-iron arranged side by side with narrow slots between them, each bar having a broad plane top wall and side walls forming acute angles therewith, whereby the said slots increase in width from their tops to their bottoms, and a frame of softer metal cast around the ends of the bars to support them and hold them in proper spaced relationship.

6. A screen-plate comprising two series of bars of hard white chilled cast-iron, the bars of each series being arranged side by side with narrow slots between them and the bars of one series having their ends in juxtaposition to the ends of those of the other series, and a frame of softer metal cast around the ends of the bars of both series to support them and hold them in proper spaced relationship.

7. A screen-plate comprising a series of bars of hard white chilled cast-iron arranged side by side with narrow slots between them and each having a longitudinal steel reinforcing rod embedded therein, and a frame of softer metal cast around the ends of the bars to support them and hold them in proper spaced relationship.

8. A screen -plate comprising a seri s of bars of hard white chilled cast-iron arranged side by side with narrow slots between them and each having a longitudinal steel reinforcing rod embedded therein and projecting from the ends thereof, and a frame of softer metal cast around the ends of the bars and the rods projecting therefrom to support the bars and hold them in proper spaced relationship.

9. A screen-plate comprising two series of bars of hard white chilled castiron each having a longitudinal steel reinforcing rod embedded therein, the bars of each series being arranged side by side with narrow slots between them and the bars of one series having their ends in juxtaposition to the ends of those of the other series, and a frame of softer metal cast around the ends of the bars of both series to support them and hold them in proper spaced relationship.

10. A screen-plate comprising two series of bars of hard white chilled cast-iron each having a longitudinal steel reinforcing rod embedded therein and projecting from the ends thereof, the bars of each series being arranged side by side with narrow slots between them and the bars of one series having their ends in juxtaposition to the ends of those of the other series and staggered relatively thereto, and a frame of softer metal cast around the ends of the bars and the rods of both series to support them and hold them in proper spaced relationship.

' 11. The herein described process of forming a screen-plate which consists in casting a plurality of iron bars, chilling the bars to produce hard white chilled iron, arranging the bars thus formed side by side with narrow slots between them, and casting a frame of softer metal around the ends of the bars to support them and hold them in place.

12. The herein described process of forming a screen-plate which consists in casting a plurality of iron bars each around a steel reinforcing rod, chilling the bars to produce hard white chilled iron, arranging the bars thus formed side by side with narrow slots -etween them, and casting a frame of softer metal around the ends of the bars and of the rods to support them and hold them in place.

In testimony whereof I have signed this specification.

PAUL S. MENOUGH.

Copies of this patent may be obtained for five cents each. by addressing the Commissioner of Patents, Washington, I). 0.

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