US1490074A - Shaker screen - Google Patents

Description

G. M. STEDMAN SHAKER SCREEN April 8 1924.

Filed July 17. 1923 v 2 Sheets-Sheet} April 8 1924.

G. M. STEDMAN SHAKER SCREEN Filed July 17 1923 2 Sheets-Sheet, 2

Patented Apr. 8, 192%.

STATES ream PATENT o-FFicE.

GEORGE M. STEDMAN, OF AURORA, INDIANA, ASSIGNOR TO STEDMANS FOUNDRY & MACHINE WORKS, OE AURORA, INDIANA, A CORPORATION OF INDIANA.

SHAKER. son-nan.

Application filed July 17, 1923. Serial No. 652,148.

To all whom it may concern:

Be it known that I, GEORGE M. STEDMAN, a citizen of the United States, and residing at Aurora, in the county of Dearborn and 8 State of Indiana, have invented a new and useful Improvement in Shaker Screens, of which the following specification is a full disclosure.

This invention relates to a screening or it separating machine commercially known as an inclined shaking or rocking screen and the present improvement has special refer-v ence to mechanism for percussively jarring the wire cloth screen to vibrate the screen is independent of any shaking or rocking action or other motion to which the screen may be subjected.

In accordance with the invention the wire cloth screen is vibrated by a hickory wood W strip extending longitudinally and centrally of the frame upon which the wire cloth screen is mounted and sustained upon the frame by bowed steel cross members fixed to the frame, the strip periodically being percussively engaged by a flexible whip member oscillated to strike the strip. An object of the invention is to actuate a screen to impart reciprocating or shaking motion to the screen longitudinally and rocking motion transversely to the longitudinal motion and to vibrate the screen cloth at the retreating rocking stroke by imparting a fiagellation to the screen cloth.

Other objects of the invention relate to the construction of the wire cloth holding frame, and means mounted upon the frame for vibrating the clothand to the mechanism for imparting a percussive impact against the wire or means for imparting the same thereto, mounted to be operated by and with the actuation of the screen, and of a construction very simple and inexpen-f sive and which is very efficient and durable. Various other features and advantages of the invention will be more fully set forth in the description of the accompanying drawings forming a part of this specification, in which: i

Figure 1 is a top plan view of the screen and its supporting structure. I Figure 2 is a section on line 22 of Fig. 1.

Figure 3 is a section on line 33, of Fig. 2.

Figure 4 is a section on line H, of Fig. 2, and

Figure 5 is a section on line 5 5, of Fig. 1.

Referring to the drawings, l1 indicate a pair of side frames of skeleton structure each, built up from timbers and connected together by, cross-beams or timbers to provide a suitable base for supporting a shaking screen thereon, and, as shown, is of a structure to. sustain the screen in an angular position. The shaking screen consists of a rectangular frame 3, formed of wooden side and end strips upon which the wire clothat is suitably secured, and this wire cloth carryingcwood frame is secured within and bounded by a metal frame 5 fabricated from angle and plate iron, with the wooden frame bolted to the metal frame, uniting the two frames into a unitary structure. The side rails or strips of the metal frame extend slightly beyond the rear end of the wooden frame, and'the extended portions thereof connected by a cross plate 6 for supporting and connecting the rear end of the screen structure to the screen actuating and transmission mechanism mounted upon the base frame, or

screen supporting structure, whereby the screen structure is reciprocated and rocked. The screen structure is reciprocated and rocked by a shaft 7 journaled and supported in bearings 88, respectively mounted and secured upon the side frames 11 of the base. structure. A pulley 9 is fixed to one end of the shaft 7 and a balance or fly wheel 10 upon the opposite end of the shaft. The shaft 7 is provided with a pair of eccentrics 1111, suitably spaced apart and respectively journaled in the bearings 12'12 depending from and fixed to the under side 'of the cross plate 6, connecting the metal side rails or strip of the screen structure. The forward end of the screen is sustained by a swinging or rocking cradle mounted upon the base structure, consisting of a pair of journal brackets 1313, respectively fixed to the side frames 1-1 of the base structure. A'shaft 14 is journaled in said brackets 1313, extending across and above the screen, and the shaft 12 has a pair of downwardly extended arms 1515 respectively at opposite sides of the screen and adjacent the journal brackets with the free end of each arm as a journal for pintles 16 fixed or secured to the underside of the screen frame.

With each revolution of the eccentrics the screen will be reciprocated longitudinally, imparting a shaking motion to the material deposited upon the screen, and rocked vertically upon the cradle with the aligned pintles 16 as axes. In addition to the shale ing and rocking motion, a tapping action is imparted to the screen in the-nature of a whip blow delivered to the portion of the screen between the cradle and the drive shaft 7, as such portion of the screen recedes in its rocking motion. The tapping action is produced by a tapperv arm 17 as a hickory wood strip fixed at one end to the rock shaft 14 centrally of the screen and extending longitudinally thereof, the free end of'the tapper being adapted to strike a stirrup 18, formed of a strip of metal bent to U-shape and fixed upon a hickory wood strip 19 extending longitudinally and centrally of the screen and at the lower side thereof. The ends of the strip 19 are rigidly fixed to the end cross rails or strip of the screen frame and intermediately to cross flexible or spring metal cross strips 20 of arched form. The opposite ends of the flexible cross strips 20 are rigidly fixed to the side rails or strip of the screen frame. For the length of screen represented by the drawings, three flexible strips 20 disposed at equally spaced divisions of the screen length are employed, although the number is optional or as may be required for obtaining various results. The wire fabric rests loosely upon the center strip 19 except at the point where the stirrup is fastened to the strip so that when a tap blow is transmitted to the stirrup, the hickory strip 19 supported upon the cross springs imparts a vibratory motion to the entire screen or wire fabric. By way of exemplification for a definite size of screen, the two eccentrics have a three-quarters throw or one and one-half inch stroke. The arms 1515 are about twelve inches long to centers, while the hickory tapper is about three feet long. The travel of the arms 1515 is one and one-half inches, and the travel of the end of the tap per where it hits the stirrup is about four and one-half inches. As the operative parts are actuated, the tapper, moving in a greater are than the descent movement of the screen, strikes the stirrup during the descent mo tion of the screen and as the stirrup recedes from the tapper. The tapper is flexible and the stirrup mounted upon a flexible strip accommodates for any excessive-motion of the tapper over that of the screen, and brings the tapper and screen strip under a resisting engagement, causing the parts to vibrate when they are first engaged and when released. Vibration of the screen strip vibrates the screen fabric, thereby loosening any screenings adhering to the screen fabric, preventing the fabric from becoming clogged. The tapper and stirrup moving in the same direction when the tapper strikes the stirrup resuits in the tapper hitting the stirrup with the least resistance, so as no to cause any appreciable wear to the parts.

Having described my invention, 1 claim:

1. In a screening machine, a frame having a wire cloth screen thereon, means engaged with said frame for vibrating and oscillating said frame, hinged cradle for swing ingly supporting said frame, and a flexible member fixed to said cradle and extending over said screen cloth adapted to flagellate the screen cloth.

2. In a screening machine, a frame having a wire cloth screen thereon, hinged cradle for swingi'ngly supporting said frame, a flexible member fixed to said cradle and extended to strike said screen cloth when the frame is actuated, and means for actuating said frame.

3. In a screening machine, a frame having a wire cloth screen thereon, means hingedly supporting said frame, and a flexible strip fixed to said frame supporting means for per-- cussively jarring said screen when the frame is actuated.

4:. In a screening machine, a frame having a wire cloth screen thereon, transmission devices engaged with said frame for actuating said frame, a cradle for hingedly supporting said frame, and a flexible'rod-like member fixed to said cradle swinging therewith to strike the wire cloth screen and percussively jar the same.

5. In an inclined screening machine, a frame having a wire cloth screen stretched thereon, a cradle for swingingly supporting said frame, transmission means for reciprocating and oscillating said frame, a flexible hickory wood strip fixed upon said cradle and swinging therewith and extending to strike the wire cloth frame centrally of the frame, a yieldingly sustained strip carried by said frame longitudinally and centrally of the wire cloth screen, adapted to be engaged by said flexible strip for percussively vibrating said wire cloth screen.

In witness whereof, I hereunto subscribe my name, as attested by the two subscribing witnesses.

GEORGE M. STEDMAN. VVit-nesses:

CHESTER A. PEEBLns, Mimeonmrn SMITH.

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