US1804115A - Screening apparatus - Google Patents

Description

y 5, 1931. M. P. REYNOLDS 1,804,115

SCREENING APPARATUS Filed Sept. 21 1927 2 Sheets-Sheet l I; a [7 P mshon Reynolds Q v M r Fig A TTORNEY Patented May 5, 1931 caries IMOBLEY PUNSHON REYNOLDS, F CLEVELAND HEIGHTS, OHIO, ASSIGNOR TO THE VI. S.

TYLER COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO SCREENING APPARATUS Application filed September 21, 1827. Serial No. 220,960.

The present invention, relating as inclicated to screening apparatus, is particularly directed to a new andimproved means for effecting the vibration of a tensioned woven wire screen. One of the principal objects of the invention is the provision in a screening apparatus of means for vibrating to substantially uniform extent practically the e11- tire surface of the screen. A further object 1 of the invention is the provision of simple unitary means for effecting the above described vibration of a taut screen.

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 description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings Fig. 1 is a plan view of a woven wire screen 5 in which is associated my improved vibrating means; Fig. 2 is a transverse central section on the line 22, in Fig. 1; Fig. 3 is a section on an enlarged scale of a tensioning means for engaging the edges of the screen;

Fig. 4: is a diagrammatic view illustrating in transverse section the vibrating action of the screen; Fig. 5 is a similar view in longitudinal section; Fig. 6 is a plan view of a modification of the invention; Fig. 7 is a similar view of another modification; and Fig. 8 is a section on the line 88 of Fig. 7

Referring now to Fig. 1, there is shown a frame 1, in which is mounted in an inclined position a woven wire screen 2. The Woven 40 wire screen is engaged along two opposite sides or edges, here shown as the lateral edges of the screen, and tensioned between these two edges. In Fig. 3 I have shown one form of tensioning means consisting of an angular strip of metal 4: engaging over a correspondingly formed edge 5 of the screen and then engaged or hooked over an angular piece 6, which is movably mounted in the frame 1 and is capable of movement transversely of the frame. The strip 4 engages all of one set of wires in the screen in the illustration shown. An adjustment of the angular pieces 6 thus stretch and tension all of the transverse wires of the screen uniformly and to any desired tension, although it has been found in practice that the screen should be tightened to produce a true vibratory drumhead tension in order to secure effective screening. The screen tensioning and gripping means illustrated in Fig. 3, and referred to above, form no part of the present invention and are described'and claimed in a copending application of August E. Helman, filed June 9, 1927, Serial No. 197,643, although it will be understood that various other means for gripping and tensioning the wires of the screen may be employed. It will also be understood that while I have here shown the lateral edges of the screen as those which are engaged and tensioned it is also possible to engage the upper and lower edges and to set up the tension in the longitudinal instead of in the transverse wires.

In screens of the character described it has been customary to vibrate the screen either P by shaking the entire frame or by vibrating the screen within the frame. In the latter case the vibration is effected either mechanically by the use of rotating unbalanced weight, by striking the screen or by electromagnetically vibrating the screen and by passing the vibrations of the screen through the medium of a centrally disposed distributing strip secured to the screen surface. In any of these methods the vibratory impulses are applied to the screen along the central line, and while an entirely suficient amplitude of screen movement is secured at this point this amplitude diminishes toward either side of the screen. Since the maximum amplitude, which is at the center, is limited cit ing bridge imparting the same amplitude to the major portion of the screen surface, and I have effected this 'esult by the following means. Extending longitudinally of the s -reen and in spaced relation to each other are two rcsilientdistributing strips which are secured directly to the screen surface and include between them the major portion of the entire screen area. These strips are parallel with the engaged edges of the screen, and if the upper and lower edges are engaged instead of the lateral edges, then it becomes desirable to mount the distributing strips transversely instead of longitudinally of the screen surface. Secured centrally to the two strips 10 is an iir-rerted cl-shaqpcd bracket 11, to the upper central portion of which is secured the armature member 12 and an electro-magnet 1? mounted in a suitable supporti, which extends across and above the screen and is carried at its ends on the frame members 1. The ele 't o-niagntic means is provided with an adjustment for the amplitude of vibration, which is secured by means of a spring 15 and hand wheel 16, which may be tightened down to increase the resistance of the spring 15 to the movement of the armatu e, and thus lessen and reduce the amplitude of mov ment of the armature. The movement of the armature is of course imparted directly to approximately the central portion of the two vibration distributing strips 10. These strips and that portion of the screen embraced between them move up and down to an amplitude indicated in Eig. l. This amplitude may be adjusted to the particular material and load passing over the screen and can be set to maintain exactly the proper movement under such conditions. No such adjustment was ever possible in machines in which the vibration was imparted to the screen at single point or along a single line parallel with he direction of movement of the material, since in such screens the amplitude at that point had to exceed the true desired amplitude in order to secure a suffi'cient amplitude at points a few inches away. The result was that a compromise adjustment was effected and accordingly almost no portion of the screen surface was receiving er;- actly the proper amplitude required, while the outer edges of the screen were moving through almost no distance and were consequently not effecting any substantial screening. The present construction permits an hccurate adjustment of the vibration to the izecpiirements and provides for this vibration over the major portion of the screen, as indieated in Fig. i.

1 (In Fig. 5 I have shown diagrannnatically a longitudinal section of the screen along the line 55, of F ig. 2. The screen, viewed 1011- gitudinally, is vibrated a maximum at the center and a minimum at the nodal points 21. In ell'ect there is a longitudinal whipping action which assists in the movement of material down the screen, and which results from the resiliency of the distributing strip 10, and it will be understood that if rigid instead oi resilient strips were employed for distributing the vibrations th vibration on the screen loi'igitudinally would be constant from top to bottom. Uncer some conditions it is desirable to use the resilient strips described and to secure the longitudinal whippin' diagrammatically illustrated in Fig. 5, as by this means some additional vibration is imparted to the top and bottom of the screen, and particularly to the corners of the screen by the whip in the ends of the two resilient distributing strips.

In Fi g. 6 I have shown a woven wire screen intended to be mounted. in an inclined position with its upper edge 26 and lower edge 27 engaged to secure a tension lengthwise of the screen through the gripping of all of the longitudinal wires. In this construction I mount vibrating strips 28 transversely of the screen and parallel to the tensioned upper and lower edges, the vibrating strips being arranged to divide the screen surface into approximately equal portions 29, 30 and 31. The electromagnetic vibrating means 32 are then mounted to operate a U-shaped bracket 33 which is secured to each of the strips 28 centrally thereof.

In Fig. 7 I have shown a similar arrangement with the addition of a single centrally disposed longitudinally extending vibrating strip 35, which may be secured on the upper surface of the screen, while the strips 28 are secured to the lower surface. Both of the arrangements of Figs. 6 and 7 provide a very effective vibration, and one which is distributed throughout the screen surface with relatively undiminished amplitude as compared with that which is secured in any of the machines employing a single vibrating mechanism secured to the screen at either a single point or at closely spaced points.

Other modes of applying the principle of 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 fol lowing claims or the equivalent of such stated means be employed.

I therefore particularly point out and dis tinctly claim as my invention 1. In screening apparatus, the combination of a frame, a woven wire screen mounted therein, means engaging two opposite edges of said screen and tensioning the same, two distributing strips secured to said screen in spaced relation, and a single vibrating means secured to said strips, said strips being of sufficient length and distributed resilience as to vibrate in wave-like form.

2. In screening apparatus, the combination of a frame, a woven wire screen mounted therein, means engaging two opposite edges of said screen and tensioning the same, two distributing strips secured to said screen in spaced relation, and means for vibrating said strips in unison and at right angles to the plane of said screen, said strips being of sufficient length and distributed resilience as to vibrate in wave-like form.

3. In screening apparatus, the combination of a frame, a woven wire screen mounted therein, means engaging two opposite edges of said screen and tensioning the same, two distributing strips secured to said screen in spaced relation and in position to include the major portion of the screen area therebetween, and means for vibrating said strips in unis-on and at right angles to the plane of said screen, said strips being of sutficient length and distributed resilience as to vibrate in wave-like form.

4C. In screening apparatus, the combination of aframe, a woven wire screen mounted therein, means engaging two opposite edges of said screen and tensioning the same, two resilient distributing strips secured to said screen in spaced parallel relation, and means for vibrating said strips in unison at right angles to the plane of said screen, said strips being of sufficient' length and distributed resilience as to vibrate in wave-like form.

5. In screening apparatus, the combination of a frame, a woven wire screen mounted therein, means engaging two opposite edges of said screen and tensioning the same, two resilient distributing strips secured to said screen in position to include the major portion of the screen surface therebetween, said strips being parallel with the engage-d edges of said screen, and means for vibrating said strips in unison at right angles to the plane of said screen, said strips being of sufiicient length and distributed resilience as to vibrate in wave-like form.

6. In screening apparatus, the combination of a frame, a woven wire screen mounted therein, means engaging two opposite edges of said screen and tensioning the same, two resilient distributing strips secured to said screen in position to include the major portion of the screen surface therebetween, said strips being parallel with the engaged edges of said screen, vibrating means, and connections between said vibrating means and substantially the central portions of said strips.

7. In screening apparatus, the combination of a frame, a woven wire screen mounted therein and having two opposite edges engaged in said frame, two resilient distributing strips secured to said screen in spaced relation and parallel with said tensioned edges, a third resilient distributing strip also secured to said screen and disposed at right angles to said first-named strips, and means connected to said distributing strips, for vibrating them, said strips being of suflicient length and distributed resilience as to vibrate in wave-like form.

8. In screening apparatus, the combination of a frame, a woven wire screen mounted therein and having two opposite edges engaged in said frame, two resilient distributing strips secured to said screen in spaced relation and parallel with said tensioned edges, a third resilient distributing strip also secured to said screen and disposed at right angles to said first-named strips, and means secured to said screen at the points of intersection of said first-named strips and said last-named strip, for vibrating all of said strips, said strips being of sufficient length and distributed resilience as to vibrate in wave-like form.

9. In screening apparatus, the combination of an inclined frame, a woven wire screen mounted therein and having its parallel upper and lower edges tensioned in said frame, two resilient distributing strips secure-d to said screen and positioned parallel with said upper and lower edges thereof, and vibrating means engaging said strips centrally of the same and adapted to vibrate said strips and therethrough said screen, said strips being of suflicient length and distributed resilience as to vibrate in wave-like form.

Signed by me, this 10th day of September, 1927.

MORLEY PUNSHON REYNOLDS.

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