US2264769A

US2264769A - Gyratory screen

Info

Publication number: US2264769A
Application number: US162661A
Authority: US
Inventors: Walter J Parks
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-09-07
Filing date: 1937-09-07
Publication date: 1941-12-02
Anticipated expiration: 1958-12-02

Description

Dec. 2, 1941. w. J. PARKS GYRATORY SCREEN Filed Sept. 7, 1937 2 Sheets-Sheet 1 Dec. 2, 1941. .w. J. PARKS GYRATORY SCREEN Filed Sept. 7, 193'? 2 Sheets-Sheet 2 p H. H. .L n

'INVENTOR Va/fer I Part;-

. n WORNQ? Patented Dec. 2,1941

crna'rcnr scanner Walter 1. Parks, Shaker Heights, Ohio Application September 7, 1937, Serial him 162,661 9 cl ims. (01. 209-326) The present invention relates to gyratory mechanism particularly adapted for use in screening materials and similar operations. The object of the invention is to provide a system of reciproeating forces which will, by their action on the and of the forces generated during the operation of the apparatus embodying my invention.

base frame or supporting structure, balance rotating forces generated in the resilientsupports of a gyrating screen.

Briefly outlined, my invention comprises the provisionof means for balancing the forces generated by the motion of a gyratory body such as a screen frame, such means consisting essentially of complementary straight line forces. My invention is particularly adapted to that type of gyrating screen mechanism wherein the actuating or driving element consists of a drive shaft ec-.

centrically journaled. at substantially the center of gravity of a resiliently supported screen frame whereby the latter possesses a gyratory motion. I have found that by means of connecting rods eccentrically connected to the drive shaft in a direction opposite to that of the eccentricity of the screen frame with respect to the center .line of the drive shaft, such connecting rods being angularly disposed with respect to each other so that their lines of effective action are complementary to each other, and that by resiliently supporting both the screen frame and the connecting rods to the base structure or supporting frame, the forces generated by the gyrating screen body and the complementarily disposed connecting rods transmissionv of vibrating forces tothe supporting frame.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following dewill counterbalance each other to eliminate the scription set forth in detail certain mechanism a embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invent on may be used.

said annexed drawings:

Fig. l. is an end elevatlonal view of an apparatus embodying the principles of my invention; Fig. 2 is a side elevational view of the apparatus shown in Fig. 1; Fig. 3 is an enlarged detailed sectional view taken through the drive shaft assembly; Fig. 4 is a smaller, detailed sectional view of a modified form of construction for the connecting rods and drive shaft; and. Fig. 5 is a diagram illustrative of the principle of operation Now referring more particularly to Figs. 1, 2 and 3 of the drawings, there is shown therein an apparatus comprising the supporting member or base frame I upon which the screen frame 2 is resiliently mounted by means of the rubber mounting blocks 3 'and t cured to metal or steel plates which in turn are carried by the frames l and 2 respectively. A drive shaft 5 is located substantially at the center of gravity of the screen frame 2 and has the eccentric portion 6.

The eccentric portion 5 is journaled in the screen frame 2 by means of the bearing 8. The eccentric bushing i, mounted on the shaft 5, is joumaled in the housing ill by means of the bearing 9. The housing In forms an integral portion of one end of the connecting rod H whose other end is resiliently connected to the base frame I by means of a rubber mounting block I2.

A second connecting rod i3 is disposed substantially at right; angles to the connecting rod ii and is connected by means of the hearing" it to the housing 60. The connecting rod l3 is similarly connected to a resilient rubber mounting on the base frame I, as indicated at IS.

The eccentricities of the eccentric portion 6 and of the bushing l are removed from each other or are disposed on opposite sides of the center line of the drive shaft 5. A drive sheave pulley I5 is mounted on the outer end of the drive shaft 5 and adapted to be connected to a prime mover such as an electric drive motor (not shown) The center line of the pulley l6 should coincide with the center line of the drive shaft 5.

A counterbalance wheel I! is also mounted on the drive shaft 5. The wheel II has a fixed eccentric weight 2! and a serrated web l8 for the adjustable radial location of the movable weights IS. The weights 2! and is are preferably so located and adjusted on the counterweight wheel II that the center mass of all of the elements connected to the drive shaft 5 is made coincident with-the center line of the shaft and midway between the eccentricities of the drive shaft portion 6 and of the bushing I. In such latter case, the

stiffness of the resilient supports l2 and ii for the centricity will have a proportionately stiffer resillent support than the larger eccentricity.

In operation, the screen frame 2 will movewwith a gyratory movement having an amplitude equal to twice the eccentricity or distance between the center of the shaft, which has been assumed to he the center of rotation, and the center of the screen body bearing 8. The housing I0, comprising the ends of the connecting rods II and I3, will also tend to gyrate about the center of mass or center line of the drive shaft 5, but diametrically opposite in instantaneous displacement with respect to the center of mass of the screen body or frame 2. The connecting rods II and I3 will not have a gyratory motion throughout their entire length inasmuch as their centers of mass are displaced from their point of eccentric con nection with the drive shaft 5. At some point in the length of the connecting rods ill and I3 they will have only a reciprocating motion along the line through their centers of mass and the center of their bearing connection to the eccentric portion l. By properly proportioning the design of the connecting rods II and I3, this lastmentioned point is made to occur substantially at the location of the resilient supports 82 and I5. Accordingly. the effective lines of action of the connecting rods II and I3, and of the forces transmitted to and generated in the resilient supports I2 and I5, will be along the length of such connecting rods. Since each connecting rod I I and I3 is rigid in a direction parallel to its length, but can tilt at right angles to its length to accommodate the gyratory motion of the housing I0, there will be no lateral displacement transmitted to the resiliently mounted ends of such connecting rods, and they will of course have only a reciprocating motion in such point of re silient attachment to the base frame I.

Inasmuch as both connecting rods II and I3 are actuated by the same eccentric, viz., the eccentric bushing I on the shaft 5, and are disposed at approximately right angles to each other, they will have a complementary reciprocating motion. That is to say, when one of the resilient supports I2 or I5 is at its maximum displacement and exerting its maximum force on the base frame, the other resilient support will have no relative displacement and will exert no additional force on the base frame. The vector sum of the displacements exerted upon the resilient supports l2 and I5 will therefore be at all times equal, since the amount of the force on one support is varying from zero to maximum while the force on the other support is varying fromvmaximum to zero. And as will be presently pointed out, the forces transmitted to or generated in the resilient supports l2 and I5 counterbalance the forces which are transmitted to and generated in the resilient supports 3 and 4 by reason of the gyratory motion of the screen body or frame 2.

Referring to Fig. 5, the motions and forces of the respective moving elements of the abovedescribed apparatus are diagrammatically illustrated upon a pair of coordinates l0! and YY which intersect at the center of mass of the system. The gyratory path of travel of the screen body moves about this center of mass and at a radius substantially equal to the diametrically oppositely disposed point of connection of the connecting rods which are designated as I and 2. The instantaneous displacement of the screen body is represented by the displacement of any point in its path of travel on the X and Y axes. Since the connecting rods I and 2 are disposed at right angles to each other, and their effective and respective displacements are along their lengths only, it will be seen, for the purpose of the diagrammatic illustration, that the connecting rod I can have an effective displacement only along the X axis, and the connecting rod 2 can have an efl'ective displacement along the Y axis. Since the eccentricities of the points of connectlon of the screen body and of the connecting rods I and 2 are removed from each other with respect to the center of mass, it will be seen that the respective effective displacement forces of the screen body and of the connecting rods are also 180 removed from each other, and thus while the screen body is moving through the first quadrant, the points of effective displacement of the connecting rods will be moving through the third quadrant of the diagram. The variation, amount and direction of the eflective forces of the screen body and of the connecting rods are analyzed in the following table which for the purpose of convenience in illustration is divided according to the four quadrants of the diagram.

The direction of motion of the forces with respectto the X and Y axes is denoted by the customary plus and minus signs.

Amount of forces Direction of forces QumL rant X axis Y axis X axis Y axis Screen bodyml. 0 to max" Maictoi) 1 Connecting rod .do 0 i T) 3 Cgnnccting rod 0 Mnx.to0. 0 3

Screen body-. Max. toO. 0 to max 2 Connecting rod .do l l l. O 4 Cgnnccting rod 0 0 to max 0 4 Screen body. 0 to max. Max. toO 3 Connecting rod ...do 0 1 Cgnnecting rod 0 Max.to0. 0 1

Screen body Max. m0 0 to max-. 4 Connecting rod ...do 0 2 Cgnnccting rod 0 0 to max.. 0 2

Referring to the above table of analysis. it will thus be seen. that the instantaneous forces generated in the resilient supports of the screen body are equal in amount and opposite in direction to the instantaneous forces generated through the connecting rods and their resilient supports, so that there is a counterbalancing at all times of the forces transmitted to the supporting frame.

Referring again to Fig. 5, the above statement is substantiated by the following analysis:

Assuming that the screen body is in a point of its pathof travel as indicated in the first quadrant, then the vector components of this point will be represented by the values which it subtends on the X and Y axes, such components being represented as X1 and Y1, respectively. At the same time, the effective point of connection of the connecting rods I and 2 is located 180 from the instantaneous point of travel of the screen body and in the third quadrant. Since the effective displacement and direction of the forces. of the connecting rods I and 2 arein a straight line only, each one of the connecting rods will have an eifective displacement along only one of the two coordinate axes. Thus, at the assumed instantaneous point, the connecting rod I will have an effective displacement as represented by the value -X1 and the connecting the drive shaft, Referring more particularly to this latter figure, the drive shaft has an eccentric bushing 2| upon which the connecting

rods

22 and 23 are mounted side by side by means of the bearings 24 and 25 respectively. The lower ends of the connecting

rods

22 and 23 are resiliently connected to opposite sides of the channel of the base frame I by means of rubber mounting blocks such as indicated at 26.

Qther modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the-means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a gyrating screen mechanism, the combination of a supporting member, a screen frame resiliently supported on said member, a drive shaft having eccentric means thereon, and individual connecting rods having one end rotatably connected to said eccentric means and the other end being connected to said supporting member, said connecting rods being disposed at right angles to each other.

2. In a gyrating screen mechanism, the combination of a supporting member, a screen frame resiliently supported on said member, a drive shaft having eccentric means thereon, and individual connecting rods having one end rotatably connected to said eccentric means and the other end being connected to said supporting member, said connecting rods being disposed at right angles to each other, and resilient means connecting said connecting rods to said supporting member.

3. In a gyrating screen mechanism, the combination of a supporting member, a screen frame resiliently supported on said member, a drive shaft having oppositely disposed eccentrics thereon, one of said eccentrics being connected to said screen frame, and individual connecting rods disposed at right angles to each other, one end of said connecting rods being rotatably connected to the other of said eccentrics'and the other end of said connecting rods being connected to said supporting member.

4. In a gyrating screen mechanism, the combination of a supporting member, a screen frame resiliently supported on said member, a drive shaft having oppositely disposed eccentrics thereon, one of said eccentrics being connected to said screen frame, and individual connecting rods disposed at right angles to each other, one end of said connecting rods being rotatably connected to the other of said eccentrics and the other end of said connecting rods being connected to said supporting member, and resilient means for connecting said connecting rods to said supporting mem-.

her.

5. In a gyrating screen mechanism, a supporting member, a screen body resiliently supported on said member, a drive shaft having portions I eccentric with respect to each other and each eccentric to a centre of rotation lying between the centers of said eccentric portions, means for connecting said screen body to one of said eccentric portions, companion balancing bodies disposed at one side of said screen body, means connecting one end of each of said balancing bodies to the other of said eccentric portions, and resilient supports for said balancing bodies mounted on said supporting member and located at points spaced from said connection of said balancing bodies to said, shaft.

6. In a gyrating mechanism, the combination of a supporting member, a gyratory screen frame resiliently supported on said member, a drive shaft having oppositely disposed eccentric means, one of said eccentric means being connected to said screen frame, connecting rods each having one end resiliently connected to said supporting member and the other end connected to the other of said eccentric means, said connecting rods so disposed relatively to each other as to create complementary balancing forces at right angles to'each other, the vector sum of which balances the forces generated in the resilient supports of said screen frame as a result of its gyratory motion.

7. In a gyrating screen mechanism,'the combination of a resiliently supported gyratory screen body, a drive shafthaving eccentric means thereon, and means comprising resilient supports and companion bodies for balancing the forces generated in the resilient supports of said gyratory body with only straight line forces generated in the resilient supports of said companion bodies, said bodies each having one end rotatably connected to said eccentric means and the other end connected to said resilient supports, said companion bodies being disposed at one side of said screen body and angularly movable with respect to each other and having an instantaneous displacement opposite to that of said gyratory screen body.

8. In a gyrating screen mechanism, the combination of a supporting member, a screen frame resiliently supported on said member, a drive shaft having oppositely disposed eccentrics thereon, one of said eccentrics being connected to said. screen frame, and connecting rods disposed at an angle of less than with respect to each other, one end of said connecting rods being rotatably connected to the other of said eccentrics and the other end of said connect-' ing rods being connected to said supporting -member, and resilient means for connecting said connecting rods to said supporting member.

WALTER J. PARKS.