US2159777A

US2159777A - Variable stroke shaking screen

Info

Publication number: US2159777A
Application number: US123574A
Authority: US
Inventors: Daniel M Blackburn
Original assignee: Hendrick Manufacturing Co
Current assignee: Hendrick Manufacturing Co
Priority date: 1937-02-02
Filing date: 1937-02-02
Publication date: 1939-05-23
Anticipated expiration: 1956-05-23

Description

May- 23, 1939.

D. M. BLACKBURN VARIABLE STROKE SHAKING SCREEN Filed Feb. 2, 1937 Minn. I;

2 Sheets-Sheet l I ll lm- I:

U HM

INVENTOR I ATTORNEY ID. M. BLACKBURN 2,159,777

VARIABLE -STROKE SHAKING SCREEN Filed Feb. 2, 1937 2 Sheets-Sheet 2 'IIIIIIII/ i :2 l I will .IIIIIHH INVENTOR 21111155 M. Bladfimnt ,I 1 A l MINI i ORNEY I Patented May 23, 1939 UNITEDSTATES PATENT OFFICE vARIABtE STROKE. SHAKING SCREEN L1 Daniel M. Blackburn, Carbondale, Pa., assignor to tion of Pennsylvania Hendrick -Manufacturing Company, a corpora- Application February 2, 1937, Serial No. 123,574

5'Claims.

This invention relates to shaking and whipping g l/screens adapted for screening materials such as 1 coal or the like and particularly to constructions frof this type in which" the amount and character of: movement of the screens may be varied to adapt the same to various conditions of operations and for handling various materials.

While the present inventionis of general application and may be used on various types of shaking and whipping screens, it is particularly adapted foruse with constructions such as that shown in the applicants issued Patent No.

2,009,219, dated July 23,1935, whereinthe screen members arecarried by resilient hangers, which i operation permit yielding movement of the screens to provide a lashing action. at each end ofthe stroke of the screens. In order to illusv trate a preferred embodiment of the invention, a typical embodiment thereof is therefore shown n the accompanying drawings and hereafter decribed as applied to a flat shaking and whipping creen of the type disclosed in said issued patent. It, is frequently desirable in screening materials to vary the stroke and speed of movement of shaking and whipping screens as they are oscillated to perform the desired shaking and whipping effect. It has been suggested heretoore that suchyariations in the strokeof shakrig and whipping screens may be effected by "connecting the screens to an oscillating hanger at points located at different. distances fromthe axis about which the hanger oscillates. However, it is not always possible or convenient to change the position of the screens or the point at which they are connected to an oscillating hanger for actuating the same. Furthermore, whenla re- 'silient hanger such as that disclosed in said issued patent is employed, much of the lashing action and resilient movement of the screens is sacri- ,ficed if the screens are connected to the hanger Fat points located close to the axis about which the hanger oscillates.

In accordance with the present invention, these overcome and shaking, andwhipping screens proand theamount and character of movement of the screens-(without changing the positions of the screens or the distance between the axes of 50 j the hangers supporting the screens and the 1 points at which the screens are connected to the hangers. Preferably the desired variations in stroke of the screen members is produced by varying the are through which the hanger is 5,5 oscillated, as distinguished from constructions ywherein the hanger is oscillated through an unvarying arc and the screens "connected to various [points on the hanger. In that form of the illvention herein describedthe are through which 160 the hanger is oscillated may be varied by embjections to constructions of the prior. art are vided with meansfor varying the stroke thereof ploying a rocker arm for actuating a rocker shaft by which the hangers are oscillated and connecting a reciprocating driving member to the rocker arm at selected points located at different distances from the axis of the rocker shaft.

One of the objects of the present invention is to provide novel means for varying the stroke of oscillating devices suchas shaking and whipping screens.

Another object of the invention is to provide a shaking screen, the stroke of which may be varied quickly and easily and without changing the position of the screens with reference to the hangers by which they are oscillated.

,'A further object of the invention is to provide a shaking and whipping screen having resilient hangers supporting the screen with means for varying the stroke of the screens without sac Figure 1 is a side elevation of a portion of a.

shaking and whipping screen embodying the present invention;

Figure 2 is a vertical sectional view of a portion of the construction illustrated in Figure 1 taken on the line 2-2 thereof; and Figure 3 is a vertical sectional view of the construction illustrated in Figure 2, taken on the line 3-3 of Figure 2.

In that form of the invention chosen for the purpose of illustrating a typical embodiment thereofland shown in the drawings, a shaking screen of the type disclosed in said issued patent is provided with a frame 2 having a pillar 4 supporting. a bearing 6 for a rocker shaft 8. A similar pillar and bearing to that shown in Figures l and 2 is located on the opposite side of the frame .for supporting the opposite end of the shaft 8 so that the shaft may be oscillated by suitable drive means. An upper screen l0 and lower screens l2 and M are supported by resilient hangers I6 located at spaced points throughout the length of the screens. ,The end hanger I8 is fixedly secured to the oscillating rocker shaft 8, whereas the remaining hangers it are mounted for oscillation on bearings 20 on supports 22 carried by the frame 2. I

As shown, each of the hangers l6 and I8 is formed of resilient strips 24, as described in said issued patent, in order to provide yielding movewrist pin 34.

with rocker arms 26 which are secured to the rocker shaft by key 28, or otherwise. The free ends of the rocker arms are formed with spaced portions 30 providing a recess 32 for receiving a The wrist pin may be secured to the rocker arms by suitable attaching means such as bolts 36, which extend through the portions 30 of the rocker arm and through the wrist pin 34,

"being held against removal by nuts 38. The portions 3E! of the rocker arms 26 are formed with a series of bolt receiving openings to permit the wrist pin to be connected thereto at selected points lying at different radial distances from the axis of the rocker shaft 8.

Suitable actuating means such as thepower driven eccentric 42 and reciprocating driving member it may be employed for actuating the rocker arm so as to oscillate the rocker shaft and the hangers by which the screens are supported.

As illustrated, the rocker arm is provided with three openings ll) for receiving the bolts or other securing means 36 by which the wrist pin is secured to the rocker arm. When the wrist pin 35 is secured to the rocker arm in the position illustrated, the radial distance between the axes of the rocker shaft 8 and the wrist pin 34 is X (Figure 3) and the arc through which the rocker shaft and the hanger is moved on each rotation of the eccentric 42 or on each reciprocating move- 0 ment of the driving member A l, is fixed to provide the desired oscillating movement of the upper and iewer screens ll], i2 and Hi. If it should be desired to increase the stroke of the screens, the are through which the hanger is oscillated may be 35 increased by removing the bolts 36 and connecting the wrist pin to the rocker arm at a point closer to the axis of the rocker shaft. The radial distance between the axes of the rocker shaft 8 and the wrist pin 3 5 then will be Y (Figure 3) m and the are through which the rocker shaft hanger are oscillated by reciprocation of the driving member 6% will be greater than when the parts are connected in the full line position illustrated. If it should be desired to shorten the stroke and reduce the arc through ,which the rocker shaft is oscillated and the hanger arms moved, the wrist pin 34 may be connected to the rocker arm by passing the bolts 36 through the lower openings 40 so that the radial distance between the axes of the shafts 8 and wrist pin 34 will be Z.

By suitably selecting the point at which the driving force is applied to the rocker arm by the wrist pin, the arc through which the rocker shaft and the hangers are oscillated and the length of the stroke of the screens may be varied hangers 15 not quickly and easily while maintaining the movement of the eccentric and of the driving member d4 constant and while also maintaining the connection between the screens and the hanger in the same position.

When the present invention is used in combination with a shaking and whipping screen having resilient hangers, the resilient nature of the varied and the advantages inherent therein are not lost or materially altered by adjustment of the stroke of the screens. Thus it is possible to handle a greater variety of sizes and types of material in a shaking screen embodying the present invention than is possible with constructions as heretofore provided.

While the present invention is particularly adapted for use with shaking and whipping screens having resilient hangers, it will of course be understood that the invention is also applicable to shaking screens using rigid hangers and to other shaking, oscillating or reciprocating devices in which it may be desired to vary the stroke or the speed of movement of the screens or reciprocating elements. It should therefore be understood that that form of the invention herein shown and described is intended to be illustrative of a typical embodiment of the invention and is not intended to limit the scope thereof.

I claim:

1. In a shaking and whipping screen having oscillatable screen members, resilient hangers supporting said screen members and a rocker shaft to which said hangers are secured, driving means connected to said shaft for oscillating said shaft to rock said hangers through a predetermined arc to produce a shaking and whipping effect and means secured to said rocker shaft for varying the are through which said driving means oscillates said shaft and hangers.

2. In a shaking and whipping screen having oscillatable screen members, resilient hangers supporting said screen members and a rocker shaft to which said hangers are secured, eccentric driving means, a wrist pin actuated by said driving means an arc secured to said rocker shaft, elements for securing said wrist pin to said rocker arm and means on said rocker arm located at different distances from the axis of said rocker shaft and engageable by said elements for selectively securing said wrist pin to said rocker arm to vary the are through which said rocker shaft and hangers are oscillated and to vary the length of stroke of said screen members.

3. In a shaking and whipping screen provided with oscillatable screening elements, resilient hangers pivotally supporting said screening elements, a rocker shaft to which said hangers are secured, a pair of rocker arms secured to said shaft for oscillating said shaft and hangers to produce a shaking and whipping effect on material being screened, a wrist pin, driving means and connections for giving said wrist pin a to and-fro movement, said arms including means for securing said wrist pin thereto at any one of a plurality of points spaced different distances from the axis of said rocker shaft to vary the arc through which said driving means oscillates said shaft, hangers and screening elements, thereby varying the shaking and whipping action of said screening elements.

4. In a shaking and whipping screen including a screening element, a rocking shaft, a resilient hanger secured to said shaft and supporting said screening element for producing a shaking and whipping action on material being screened, a driving means for producing a to-and-fro motion, means for connecting said driving means to said shaft to oscillate same, said connecting means including an adjustable arrangement for varying the arc through which said shaft and hanger oscillate, whereby the shaking and whipping action of said screening element may be varied.

5. In a shaking and whipping screen a plurality of resilient hangers, a shaft to which said hangers are secured, upper and lower screen members secured to said hangers on opposite sides of said shaft, driving means connected to said shaft to oscillate the shaft and hangers through a predetermined arc to produce a shaking and whipping effect, and means secured to said rocker shaft for varying the are through which said driving means oscillates said shaft and hangers.

DANIEL M. BLACKBURN.