US2456248A - Gyratory screen - Google Patents

Description

as. m, 1948.

F. J. BERRY GYRATORY SCREEN Filed Sept. 8. 1945 IN WE N TC R. zfweau s mw:

Fqmw w Patented Dec. 14,, 1948 UNITED STATES PATENT OFFICE GYRATORY SCREEN Francois Jacques Berry, Lille, France Application 2 Claims. 1

It has already been suggested, in the construction of sieves adapted for the granulometric or densimetric sorting out of products in a divided state, to control the motion of the sieve by means of an eccentric, the strap of which is fast with the movable part, the latter being suspended at its ends by means of springs making it possible to cause all the points of the sieve to follow parallel trajectories. In this case, the trajectory of each point is a circumference of a small amplitude.

The present invention has more particularly for its object to provide an improvement in or relating to the control of the movements of such sieves in order to cause each point of the sieve to follow an elliptic trajectory having a selected amplitude and a selected slope so as to obtain, for the particles to be treated on the sieve, advancing movements adapted to ensure the sorting out of said particles according to their dimensions or their densities under better conditions. I

For this purpose, according to the invention, the control device for the movements of the movable frame of the sieve comprises, preferably on each side of the latter and close by the centre of gravity of the movable unit, two eccentrics fast with a common driving shaft and'the centres of which are situated in one and the same diametral plane of said shaft, said eccentrics being connected with the frame of the sieve by two connecting rods keyed at 90 from one another. The rotation of the driving shaft then determines for each point of the sieve a displacement according to an ellipse the two half-axes of which correspond respectively to the ofisettings of the eccentrics. According to the vertical or slanting position given to the connecting-rod of the eccentric having the greatest offsetting, for instance, the obtained trajectory is an ellipse with a vertical or slanting major axis.

According to another characteristic feature of I the invention the device for the suspension of the sieve comprises four links arranged near the four 1 angles of the movable frame and formed each of two telescopically jointed members kept apart by compressed springs, each of said links being articulated at its ends, on one hand, on the fixed frame of the apparatus and, on the other hand, on the movable frame of the sieve. A simple and advantageous kind of articulation of the supporting links may consist in providing the sliding pieces forming each of the latter with heads having a cylindrical or spherical surface and leaning respectively against resting faces fast with the fixed frame and the movable frame and provided September 8, 1945, Serial No. 615,183

In France May 14, 1943 2 with transverse grooves engaging corresponding projections provided on said resting faces.

The improved sieves according to the invention may eventually be placed, in the known manner, in a liquid or gaseous medium (as in the case of a pneumatic purification) to which a continuous or discontinuous flowing movement may be imparted or not:

A form of execution of the arrangements which form the subject-matter of the invention is shown by way of non-limitative example in the appended drawing, in which:

Fig. 1 is a diagrammatical elevational view of the movable unit of the sieve with its elastic suspension.

Fig. 2 is a vertical axialsectional view, ona larger scale, of one of the lateral control devices for the movements of the sieve, taken on the line II--II of Figure 3.

Fig. 3v is a sectional view taken throu h line III-III oi. Fig. 2.

Fig. 4 shows the elliptic trajectory described in this case by each point of the sieve.

Fig. 5- is a vertical view of one of the links for the suspension of the sieve, and

Fig. 6 is a similar view of a modification.

In Fig. 1, i shows the shifting screen of the sieve which is held fast between two longitudinal members 2 resting at their ends on two pairs of spring supports or links 3. The control device for the movement of the sieve, which is shown in A, is

centre and the centres 01 02 of which are situated in one and the same diametral plane and the offsettings 001 and 002 of which correspond respectively to the lengths of'the half-axes of the ellipse along which the different points of the sieve are to travel. The two eccentrics 1a, 1b are connected with the two cheeks of the housing 4 by links 8a, 8b, keyed at from each other and by axes 9a, 9b. Therefore, the rotation of the eccentric Ia determines displacements of the housing 4' and, accordingly, of the whole sieve according to a toand-fro movement the amplitude of which is equal to its stroke and according to the direction O-Oa, while the rotation of the eccentric lb deterw on, D2. or, and (12.

3 mines another to-and-fro movement the amplitude of which is equal to the stroke of said eccentric and according to the direction 9b, Through combining with each other, both said orthogonal movements impart to the sieve a re- .an elliptic trajectory the great axis of which would be slanting, as shown in broken lines in Fl 4.

The spring links 3 through which the longitudinal members of the sieve are supported at their ends and which makes it possible for all the points of the sieve to describe the same movement may be constituted respectively, as shown in Fig. 5, by two pieces III, II sliding in each other and kept apart from each other by a spring l2. Said pieces are provided with heads Illa, 101) having a cylindrical surface and through which they lean, on one hand, against a resting I3 integral with the fixed frame of the apparatus and, on the other hand, against a face integral with the corresponding, member 2. In order to avoid any displacement of the spring links on their supports I xii-H their heads are provided with transversal grooves b, Hb having a suitable profile and engaging projections l3a, Ha having a corresponding profile and provided on the resting faces l3 and I4. Under these conditions the horizontal displacements of the sieve cause the links 10- to turn on the projections l3a, l3b; the vertical displacements are effected through a compression or an extension of the links. Since the springs and the links have the same characteristics, the

displacements of thesieve are the same in all points.

The cylindrical or spherical rolling heads 10a, Ila might be substituted by sockets such as a, I So (Fig. 6) which would be engaged by axes held fast respectively on the fixed part and on the movable part of the apparatus.

In order to make it possible to change the setting of the connecting rods 8a and 8b with respect to the frame of the sieve for modifying at will the slope of the major-axis of the ellipse described by the elements of the sieve with respect to the horizontal line, the housing 4 might be mounted so that it could befpossible to displace it angularly around the'axisofthe shaft 5, for instance by means of an adjusting mechanism comprising a worm engaging a'helicoidal wheel fast with the housing.

An arrangement such as described above is shown in Figures 2 and 3. The housing 4 is attached to the frame 2 by means of headed studs or, in, m. and d1, which ride in the arcuate slots The frame 2 is provided with slots I So and l9b in which ride the axles and 9b. The housing carriesa toothed sector l6 cooperating with a worm I! mounted in bearings Ila. and lib. Theposition of the links Ila-and lb may be adjusted by rotating the worm I] so as to vary the position of the major axis of the elliptical path of the sieve.

What I claim is: v

1. In a sieve for sorting solid materials comprising a movable frame spring mounted at its ends, a driving shaft for said frame, two eccentrics fixed on said driving shaft near the center of gravity of said frame, the centers of said eccentrics being located in the same diametr-al plane of said shaft, a connecting rod fixed to each of said eccentrics, a housing for said connecting rods rotatably mounted on said frame for rotary movement around the axis of the shaft, and said connecting rods at their ends being pivoted to said housing, at an angle of 90 to each other, and means connected between the housing and the frame for adjusting the housing about the axis of the shaft, whereby angular displacement of said housing will vary the major axis of the elliptical pathof said sieve.

2. In a sieve for sorting solid materials comprising a movable frame spring mounted at its ends, a driving shaft for said frame, two eccentrics fixed on said driving shaft near the center of gravity of said frame, the centers of said eccentrics being located in the same diametral plane of said shaft, a connecting rod fixed to each of said eccentrics, a housing for said connecting rods rotatably mounted on said frame for rotary movement around the axis of the shaft, and said connecting rods at their ends being pivoted to said housing at an angle of 90 to each other, and means connected between the housing and the frame for adjusting the housing about the axis of the shaft, said housing being provided with a toothed sector and said frame carrying a worm operatively engaging said sector whereby rotation'of said worm produces angular displacement of said housing to vary the major axis of the elliptical path of said sieve.

FRANCOIS JACQUES BERRY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 00 794,555 Scovell July 11, 1905 1,207,803 Scovell Dec. 12, 1916 1,693,940 Robins Dec. 4, 1928 1,730,435 Munro Oct. 8, 1929 1995,435 Overstrom Mar. 26, 1935 1,999,768 Lincoln Apr. 30, 1935 2,109,395 Markley Feb. 22, 1938 2,200,724 Robins May 14, 1940 2,212,550 Parks Aug. 27, 1940 2,264,769 Parks Dec. 2, 1941 2,374,663 'Carrier May 1, 1945 2,414,993 Wiegan Jan. 28, 1947 2,415,993 Cottrell Feb. 18, 1947 FOREIGN PATENTS Number Country Date 616,578 Germany Aug. 1, 1935 666,779 Germany Oct. 28, 1938 411,913 Great Britain June 18, 1934

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