US1961669A - Gyratory sifter - Google Patents

Description

- June 5, 1934. I L. KEEPER I 1,951,669

- GYRATORY SIFTER- Filed March 11, 1931 s She'ets-Sheet 1 mm E .ZflaZierlfiger June 5, 1934.

W. L. KEEFER I GYRATORY SIFTER Filed March 11. 1931 3 Sheets-Sheet 2 SWIM/om Zfla ZZerl. 6 948? Patented June 5, 1934 UNITED STATES GYRATORY SIFTER Walter L. Keefer, Chambersburg, Pa., assignor to Harry G. Wolf, Chambersburg, Pa.

Application March 11, 1931, Serial No. 521,814

1 Claim.

The invention relates to grading, sifting, screening and analogous machines of a known type in which the screening frame or the like is gyrated by rotary power-driven means disposed vertically and having an eccentric connection with said frame, the aforesaid rotary means being stationarily mounted upon a floor or other adequate supporting means. During its gyration, the frame creates a powerful centrifugal force, which unbalanced would produce severe vibration to the detriment of the machine and the mill or the like in which used, as well as causing great annoyance. It is the principal object of the present invention however, to provide novel means whereby the aforementioned centrifugal force is so balanced as to prevent excessive vibration, hence becoming unobjectionable.

A further aim is to provide novel means for holding the screening frame or the like against rotation while permitting it to gyrate.

Yet another object is to provide a comparatively simple and inexpensive construction, yet one which will be efficient and desirable from various stand-points.

With the foregoing in view, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished by reference to the accompanying drawings.

Fig. 1 is a side elevation of a gyratory sifter embodying my improvements.

Fig. 2 is a top plan view'partly broken away, showing the mechanism for gyrating the screening frame or the like, the frame being omitted from this view.

Fig. 3 is a vertical sectional View partly in elevation as indicated by line 3 -3 of Fig. 2.

Fig. 4 is a horizontal sectional view on line li-4 of Fig. 3.

A preferred construction has been shown and will be rather specifically described, with the understanding however, that within the scope of the invention as claimed, numerous variations may be made.

The numeral 5 denotes a horizontal base frame adapted for anchorage to a floor or other support, said frame being shown as provided with feet 6 for anchorage purposes. The frame 5 embodies a rigid horizontal spider '7 which supports a rigid upstanding bearing stub 8. A short vertical shaft or hub 9 is rotatably mounted upon this hearing stub 8, being provided substantially throughout its length with a bore 10 in which said stub is received. The lower end of bore 10 is enlarged at 11 and contains an anti-friction bearing 12 arranged to resist downward thrust as well as radial thrust. Another anti-friction bearing 13 centers the upper end of the bearing stub 8 in the bore 10.

The shaft or hub 9 is provided with a second bore 1 extending substantially throughout its length and enlarged at its upper end as shown at 15. A second bearing stub 16 is rotatably received in the bore 14 and is provided near its upper end with a bearing 17 similar to the bearing 12. with a bearing 18 similar to the bearing 13. The upper end of the stub 16 rigidly supports a saddle 19 for the screening frame or the like 20.

The saddle l9 embodies an elongated horizontal plate 21 whose center is rigidly supported by the stub 16, the ends of said plate being provided with integral vertical flanges 22 which are disposed in parallel planes. Between their ends, the flanges 22 are provided with slots or other openings 23 receiving bolts or other trunnions 24 projecting from opposite sides of the frame 20, which sides are engaged by the flanges 22. Near their ends, these flanges 22 are provided with vertical slots 25 which receive clamping bolts 26 engaged with the frame 20. When the bolts 26 are loosened, frame 20 may be tilted to the most desired position or may be leveled, as may be required, and tightening of the bolts will then secure said frame to the saddle 19.

I have shown a pulley 27 on the lower end of the shaft or hub 9, said pulley engaging a drive belt 28. This belt may be driven by an electric motor 29 or otherwise. The additional belt 30 shown in Fig. 1 is part of driving means for a feeder (not shown) which feeds the material to be screened, sifted or the like, into the inlet 31 of the screening frame 20. While I have referred to this member 20 as a screening frame, it is usually of box-like form, but as my improvements are operable regardless of the type of frame, the invention is not to be considered as restricted to one kind of screening frame or another. Moreover, gyratory members for performing work other than screening, could Well be substituted for the frame 20.

As the shaft or hub 9 is rotated, the frame 20 is gyrated and during its gyration, said frame creates a powerful centrifugal force. Connected with the lower portion of the shaft or hub 9 and preferably secured to the lower side of the pulley 27, is a weight 32 which also creates centrifugal force while the machine is in operation. The centrifugal forces generated by the frame 20 and the weight 32, are substantially equal and are exerted in the same direction. In a plane between the weight 32 and the frame 20 however, another weight is secured to the shaft or hub 9, said other weight creating a centrifugal force in the opposite direction from that created by the parts 20 and 32, and said opposite centrifugal force is substantially equal to the two aforesaid forces com bined. The additional weight in question, is here shown as consisting of one mass 33 integral with the upper end of the shaft or hub 9, and an aux- The lower end of the stub 16 is equipped iliary mass 34 secured by cap screws 35 to said mass 33. The weight 32 is preferably secured by bolts or the like 36 to the pulley 2'7, and when frames 20 of different sizes are used, or when different numbers of screens or the like are employed within said fr mes, the weights 32 and 34 may be detached and others substituted having the requisite mass for producing the desiredcounterbalancing.

By providing the structure in which the frame 20 and the weight 32 exert substantially equal centrifugal forces in one direction, and in which weight 33-3l or the like creates an opposite centrifugal force substantially equal to the two aforesaid forces combined, a structure is produced which is in substantially dynamic balance, so that practically no Vibration will take place in the operation of the m chine.

Provision is made for holding the saddle l9 and the frame 20 against rotation, while permitting the necessary gyration, and like the gyrating and balancing means, said provision for preventing rotation, is disposed totally beneath said frame 20. The structure described below is preferably followed.

A forked bracket 3'? is suitably secured at 38 to the plate 21 and projects laterally therefrom. A similar forked bracket 39 is secured by belts or the like 4-0 to the base frame 5. Upper and lower universal joints 41 and 42 are pivoted on horizontal axes l3 and 44 respectively, between the arrns of the upper and lower brackets 37 and 39, said join s held against rotation by said brackets. A short vertical shaft 45 extends between and is operatively connected with the universal joints ll. and i2 and is held against rotation by said joints. The shaft however may describe a conical pendulum. Thus, while this shaft will allow the proper gyration of the saddle l9 and the frame 20, it will not allow rotation of these parts.

Preferably, a suitable housing so is mounted on the base frame 5 around movable parts, said housing having openings 47 through which the belt 28 passes.

By providing the novel construction shown and described, or a substantial equivalent thereof, a machine is provided which will smoothly operate in substantially dynamic balance and will be highly efficient. Attention is invited to the fact that all off-center weights for dynamically balancing, are below the frame 20. I am aware that one weight has heretofore been used at a similar location in an attempt to dynamically balance the frame, but has proven inefficient. The weight to which refer necessarily rotates in a plane below the plane along which the center of mass of the frame (corresponding to 20) travels. The two masses consequently seek a common plane as the machine is rapidly driven, and in so doing, they exert a tremendous leverage upon the rotary frame gyrating means. In my invention however, the opposing centrifugal force created-by the weight or the like, is in a plane between the planes in which the frame 20 and the weight 32 exert their centrifugal forces. Hence, the above nentioned leverage action substantially disappears.

A much more desirable and durable construction than has heretofore been provided, is produced by using the long overlapped bearing studs 8 and 16, disposed in bores extending substantially throughout the length of the short shaft or hub 9. While this structure is preferred, it is of course to be understood that within the scope of the invention as claimed, some other suitable rotary supporting means could be provided for the shaft or the like 9, and that other desirable provision could be made for establishing an eccentric connection between the upper end of said part 9 and the frame 20. Similarly, while the universal joints of the shaft 45 are preferably employed to hold the frame 28 against rotation, other provision could of course be made for this purpose. The parts in question however are desirable not only because of their simplicity and efficiency, but because they, like all other moving parts, are totally below the frame 20, being therefore absolutely out of the way.

'While only one embodiment of the invention has been disclosed, it is to be understood that it may well assume other forms. Moreover, while the disclosed construction supports the screen ing frame 20, it will be understood that this frame could be supported in oti er ways. Moreover, while in the present embodiment of the invention, the same shaft which drives the counterbalancing weights, imparts the gyratory motion to the screening frame, it will be understood that such motion could be supplied in other ways, utilizing the gist of the present invention only for counter-balancing purposes.

I claim:

In a screen gyrating means, a horizontal base having side bars and an end bar, a horizontal spider having two arms secured to said side bars and a third arm secured to said end bar, an upstanding stub shaft rigidly carried by said spider and having a weight-sustaining roller bearing at its lower end and a radial thrust hearing at its upper end, a vertically elongated shaft having two parallel bores each extending substantially throughout its length, said shaft being supported by said weight-sustaining bearing and receiving said stub shaft and said radial thrust bearing in one of its bores, a screen support over said shaft having a downwardly projecting stub shaft and a weight-supporting roller bearing around the upper end thereof, the lower end of said stub shaft being provided with a radial thrust bearing, said downwardly projecting stub shaft and its radial thrust bearing being received in the other bore of said vertically elongated and the weighasupporting bearing of said downwardly projecting stub shaft being supported by the upper end of said vertically elongated shaft, a pulley joined at its center to said vertically elongated shaft near the lower end of the latter, a relatively light weight secured to said pulley and disposed at the side of the vertically elongated shaft adjacent said downwardly projecting stub shaft, whereby said relatively light weight and the scr: n may exert centrifugal forces in the same direction, and a relatively heavy weight at the other side of said vertically elongated shaft and rigidly joined to the upper end thereof for exerting 2. corresponding centrifugal force in the other direction; an upper bracket secured to said screen support, a lower bracket secured to one of said side bars of the base and projecting inwardly from the latter, a vertical shaft extending between said upper and lower brackets, and universal joints eonnecting the ends of said vertical shaft with said

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