US1459838A - Vibrating screen - Google Patents

Description

Jwii 26, 1923.-

' B. A. MITCHELL ViBRAIING SCREEN original Filed May 6, 1918 3 Shuts-Supt W3 wk #6 MM W, W4 7 1 ,m

June 26, 1923. 1,459,838

B.-A. MITCHELL VIBRATING SCREEN Original Filed may 6, 1918 {Shuts-Shut 2 Lm \ml June'26, 1923. 1,459,838

B. A. MITCHELL VIBRATING SCREEN Original Filed May 6, 1919 s Shuts-Sheet 5 Patented June26, 1923. I

UNITED STATES PATENT OFFICE.

BENJAMIN A. MITCHELL, or GARFIELD, UTAH, assrenon or TWO-THIRDS T0 MINNIE L.,MrroHELL, or MAGNA, UTAH.

VIBRATING SCREEN.

Application filed May 6,1918, Serial No. 232,798. Renewed January 25, 1923.

To 055 whom it may concern Be it known that I, BENJAMIN A.

MITCHELL, a citizen of the United States,

residing at Garfield, in the county of Salt' Lake and State of Utah,'have invented certain new and useful Improvements in Vibrating Screens, of whichthe following 13 a specification. I

This invention relates to a vibrat ng screen, and its purpose is to provlde 1mproved apparatus for use in screening ore,

sand, gravel and various other materials. 7 The principal object of the invention 1s to provide a screen having improved means for imparting thereto a true vibration as distinguished from aseries of impacts. {inother important object is to provide 1mproved vibrating means located in the plane of the screen, whereby true vibration is imparted to the screen in the plane thereof and a more perfect screening action secured. Still another important feature of the invenln'the drawings Figure 1 shows a top plan view of one form of my invention;

Fig. 2 shows a side elevation thereof; Fig. 3 shows a longitudinal sectional view through my improved rotary vibrator;-

Fig. 4 shows anend view of the vibrator; Fig. 5 shows an end view of the rotary vibrator member mounted within the casing of'the vibrator; Fig.- 6 is-an enlarged detail view showing the clamping means for securing the lateral edges of the screen; and

F 1g. 7 1s a VIGW'SImIlaI' to F1g2, showing the application ofthe invention toa' machine havi plurality of screenin mediumsw' Referring to the drawings, it will be seen that the invention comprises a rectangular frame 10 which is held in, an inclined position by any suitable supporting means, such as the supporting arms llpivotally connected at 12 to the lower part of the frame, and the extensible supporting members 13 connected to the upper part of the frame and provided with clamping means 14 by which these arms may be adjusted in length to vary the inclination of the frame. The screen 15 of wire cloth or other suitable material is mounted above the rectangular frame 10 and the lower edge thereof is extended over a cylindrical bar or roller 16 carried by the frame. The lower edge of thescreen is then wrapped once around a rod 17 located within a pipe 18 having a longitudinal slot 19 in the side thereof. The rod 17 is of greater thickness than the width of the slot 19, so that when a pull isexerted on the pipe 18 in a downward direction, the screen is securely clamped between the rod and the walls of the slot. The pipe 18 is held by two or more clamping bolts 20 having arms or fingers 20 to extend partially around the 'pipe, and these bolts are extended through suitable apertures in the flange 21 of the frame, being threadedly engaged at their lower ends by the adjusting nuts 22, so that the tension of the screen may be adjusted by varying the positions of these nuts.

The upper edge of the screen is also wrapped around a rod'23 located within another slotted pipe 24:, and this last-named slotted pipe is connected by a belt or other suitable device 25 to the rotary vibrator designated generally by the numeral 26.- This vibrator is located upon the upper part of the frame 10, and has its central axis in the same plane as the screen 15, as will be apparent from an inspection of F ig. 2. The mate rial to be screened is fed to the screening medium 15 from a feed box 27 having an opening 28 in the bottom thereof, and an inclined plate 29 by which the material passing through the opening is directed onto the upper part of the screen.

The unbalanped rotary vibrator 26 may 1 preferably have the general form illustrated in Figs. 3 'and' 4, where it is shown as comcylindrical in form, but are reinforced on their outer sides by longitudinal ribs 32. A shaft passes through apertures in the Wallsot' the, central housing 3.0 and extends therefrom into each of the casings 31. This shaft may be driven through a belt mounted on theopulley 34 located withinthe housing or, if desired,"the housing 30 may form the casing of an electric motorhaving its armature located directly on theshaft. At the inner end of each of the casings 31, the shaft 33 has mounted thereon a bearing member 36 which has an annular wearing V casing 31.

rin 37 secured thereto by a lock-nut 38. Ball-bearings 3,9 aremounted between the ring 37 and the annular ring 4. .0.. which is. secured Within the outer wall of the within thev housing 31. is secured by a key 41 to an unbalanced vibrator member 42, which is provided at opposite ends with cylindrical parts 42? forming bearing members to carry the annular rings 43 which cooperate with the outer rings 44 carried bythe-casing to form annular raceways for the balLbearings 45. The bearings, thus formed are spaced apart within the casing and the vibratory member 42 is provided with aneccentric projection 42" on I one side thereof which serves to unbalance the same and causev vibrations to be imparted to the casin when the vibratory member is rotated. his unbalancing effect is increased, without unduly extending the pro1ectron 4:2", by providing an aperture 42 through the bearing member disposed oppositely tothe projection 42 with respect to the central axis; of the member. The outer end of the vibrator member 42 has a thrust washer 46 seated in a recess therein, and this washer has a small projection 46 which is adapted,upon lateral movement of the vibratory membexgto coact with the rounded surface of a steel nut 47 which is mounted in the end, wall'o1' web 31 of the casing 31.

brator 61, which isilocatec b with its central,

lXli .S bSWMiHHY ,midway between .the

P i -1 fi llp e he twd screens 62 and.

"63, which are connected to thecasing of the ll lit h itt: by connections ste lar t t ose prev ously described ,j and ,W QKh XQ thQ1 1 W6I ends over bars or The extremity of the shaft 33 In Fig. of the drawings, I have illusrollers 65 and connected to the lower end of the frame by adjustable connections 66.

The material is fed to the upper screen,

which may. be of relatively. coarse mesh, from a feed box 68, and the material after passing through this screen is subjected to a further screening action by the lower screen (53 which maybe of finer mesh.

In this invention the rotary vibrator may be driven at relatively high speed either by belt or motor, so that thirty-five hundred vibrations perminute or, moremay be imparted to the screen from the casing of the vibrator, thus giving the screen a true vibratory action of high frequency which serves to effectfa more speedy and perfect screening action then that accomplished by,

devices heretofore known. An important feature ofthe invention is that the vibrations imparted to the screen are true vibrati ons of high frequency occurring with regularity as distinguished from intermittent im- P ts impa ted t th s r ns, s c as th I which are produced by the use of pneumatic imPfiQt vibrators, and the like. By locating the vibrator in the plane of the screen, the

screen is given a reciprocating action in its own plane, which is found to be beneficial in securing a perfect screening of the material fed to the mesh. By changing the inclination of the frame, the rapidity with which the material passes downwardly over the screen may be regulatedas desired; A sheet,

of rubber, or the like, may be inserted between the vibrator casing and the frame to permit greaterfreedom of vibration,

" Although Ihave shown and described but two embodiments of the invention for purposes of illustration, it will be understood that maybe constructed in widely different forms without departing from the spirit of the in e ion as defined in the appended claims.

Wha I claim li t 1. In apparatus of the class described, a screen, supporting means connected to said screen, means located in the plane ofthe SCreen for producing high frequency vibrations in a plane perpendicular to the .plane of thescreen, and means for transmitting said vibrations to said screen.

2. In apparatus of the class described, a stationary frame, a screen supported by said frame, a rotary vibratory device located in the plane of said screen, means'for actuating said vibratory device to produce high fr e,quency vibrations. and means connected to said vibratorydevice and said screen for imparting said vibrations to said screen. 3. In apparatus of the class described, a finame, a screen supported bysaid frame, a

-,,vibrator casingmounted in the plane of said screen and connected theretopindependently-of said frame, alrunba'lanced rojtary member mounted in said vibratory casing, and

, brator casing, and means for rotating said 1 means for rotating said member and thereby imparting vibrations to said casing: and said screen- 1 t. In apparatus of the class described, a frame, a screen, means for connecting one edge of said screen to said frame, a vibrator casing connected to the opposite edge of said screen, meansfor maintaining said screen continuously under high tension, an unbalanced rotary member mounted in said vimember at high speed and thereby imparting high frequency vibrations to said casing and said screen.

5. In apparatus of the class described, a frame, a screen, means for connecting one edge of said screen to said frame, a vibrator casing located in the plane of said screen, means for connecting an intermediate part of said casing to the opposite edge of said screen, means for connecting the ends of said casing to said opposite edge of'said screen, an unbalanced rotary member mounted in said casing, and means for rotating said unbalanced member.

6. In apparatus of the class described, a screen, means for supporting said screen, a vibrator casing connected to said screen independently of its frame, a shaft journaled in said casing, unbalanced rotary members mounted in said casing and actuated by said shaft, and means connected to said shaft in said casing for rotating the same.

7. In apparatus of the class described, a stationary inclined screen, means for holding said screen in a stiff rigid condition, means located in the plane of said screen for producing high frequency circular vibrations, and means for connecting said last named means directly to said screen.

8. In apparatus of the class described, a frame, a screen, a vibratory device mounted on said frame and connected to one edge of said screen, means for connecting the opposite edge of said screen to said frame, means for maintaining said screen under high tension, and means for operating said vibratory device to produce high frequency vibrations in said screen independently of said frame.

9. In apparatus of the class described, a frame, a screen mounted Within said frame, a vibrator connected to one edge of said screen, a bar over which. the other edge of said screen is passed, and adjustable means connected to the other edge of said screen below said bar for adjusting the tension of said screen.

10. In apparatus of'the class described, a screen, a vibrator casing, a rotary vibrator mounted in said casing, said casing having a tapered part, a ring adapted to fit on said tapered part. means for holding said ring on said casing, and means for connecting said ring to said screen.

11. In apparatus: of the class described, a

rotary vibrator comprising a central housing, a shaft extendingthro. -ugh said housing, means mounted in said housing for rotating said shaft, a casing carried by said housing, a bearing mounted in said casing and having said shaft journaled therein, and a otary nember centri y m unt d po said shaft within said casing for effecting vibration of said casing and housing upon rotation of said shaft.

12. In apparatus of the class described, a vibrator casing comprising a central hous ing, a shaft extending through said housing, means mounted in said housing for rotating said shaft, casings mounted at opposite ends of said housing and enclosing the ends of said shaft, roller bearings mounted in said casings and having said shaft journaled therein, rotary members mounted in said casings and connected to said shaft, and other roller bearings for said rotary members, said rotary members having parts disposed eccentrically With respect to the axis of rotation of said shaft whereby a vibration is produced in said casings and said housing by the rotation of said shaft.

13. In apparatus of the class described, a vibrator casing, a member adapted to be rigidly attached to said casing, a screen, and a plate carried by said member for connecting said vibrator casing with said screen.

14. In apparatus of the class described, a screen, a vibrator casing having a circular part, a ring adapted to fit over'said circular part, and a plate connected to said ring and engaging said screen.

15. In apparatus of the class described, a vibrator casing, a shaft mounted in said casing, means connected to the central part of said shaft for actuating it, and unbalanced rotary members mounted on. said shaft in opposite ends of said casing.

16. In apparatus of the class described, a vibrator casing, a shaft mounted in said casing, means connected to the central part of said shaft for actuating it, unbalanced rotary members mounted on said shaft in opposite ends of said casing, a screen, and means for connecting opposite ends of said vibrator casing directly to said screen.

17 In apparatus of the class described, a

frame, a vibrator mounted rigidly With reframe, a screen mounted said casing for transmitting vibrations therefrom, and a screen connected to and partially supported by said plate.

20. In apparatus of the class described, a

6 vibrator casing means for producin vibrations in said casing, a plate connectecl to said casing for transmitting vibrations therefrom, a screenconnected to and partially supported by said plate, and additional n BENJAMIN A. MITCHELL.

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