US1993615A - Mounting of oscillating apparatus - Google Patents

Description

March 5, 1935.

J. w. MURRY MOUNTING OF OSCILLATING APPRATUS Filed March 14, 1932 2 Sheets-Sheet 1 INVENTOR March 5, 1935. J, w. MURRY fifi fiw MOUNTING OF OSCILLATING APPRATUS Filed March 14, 1952 2 Sheets-Sheet 2 Patented Mar. 1935 PATENT FFl 4 Claims.

This invention relates to the mounting of pro pelling apparatus for driving oscillating machinery, and the object in view is to relieve of vibration the supporting structure. It involves necessarily a plurality oi members to oscillated, whose masses severally vary, one relatively to another, in the course of service, and the invention is realized in driving the plurality of oscillatory members from a common member which is itself oscillatory in compensatory dearea to the variations of mass alluded to. The invention finds practical application in the driving of various pieces of apparatus: picking tables, for example, coal-cleaning tables, shaker screens,

oscillatory apparatus generally; and, in exemplary way, I shall describe it in applicationto shaker screens, for sitting sand, coal, and the like.

In the accompanying drawings Fig. I is a fragmentary view in side elevation of a pair of shaker screens equipped with oscillating machinery and embodying the corrective feature of my invention. Fig. II is a similar view, illustrating a variation 'in detail. Fig. HI is a fragmentary view in end elevation and illustrating another variation in detail. Fig. IV is aview in horizontal section, on the plane indicated at IV-IV, Fig. I, and showing in plan certain parts of the apparatus. V is a view corresponding to Fig. I and illustrating another specific cmbodl-= ment of the characteristic feature of the invention. Fig. V1 is a view in side elevation of a portion of'the apparatus shown in Fig. V. Fig. VII is a view in horizontal section, on the broken plane indicated at VII- VII, Fig. V, and showing in plan the driving connections.

Referring to Fig. I, two screens 1 and 2 are shown to be suspended by links 3 from the structure e of a building in which the apparatus may be understcod to be housed. It is to relieve the structure of the building of the vibration otherwise incident to the driving of the screens 1 and 2 that my invention is intended.

Thegscreens, it will be observed, are arranged a in inclined positions, on a substantially continuous slope; a feed hopper 5 delivers to the upper screen 1 and the upper delivers to the lower screen 2.

The two screens are connected by rods e and 7 to eccentric disks 8 and 9 carried by shaft 1G,

and by this arrangement shaft rotation effects screen oscillation. The eccentrics are relatively placed on the shaft in diametrically opposite positions, consequence of which the move oppositely: as one is shifted to the left the other is shifted to the right.

In practical service it comes about that the burdensupon the two screens are oitenare usually, indeed-unequal, and the inequality varies 5 from time to time and may at times be very great. In consequence of this condition, the shaft 10, if it be mounted (as ordinarily it is) on bearings which are rigid in the structure of the building, must in the course of each revolution 0 sustain a varying load. Vibration is set up, and the vibration is communicated to the structure of the building, with results which in the long run are serious. Variation is therefore to be 4 avoided, and I have invented means of avoiding it.

I mount the shaft 10 upon a platform ll and I hang the platform 11 by links 12 from the structure 13 of the building. Both the screens 1 and 2 and the driving shaft 10 then are hung, and the inequalities of load which otherwise would express themselves in vibration of the structure (if the shaft journals were rigidly attached to same), express themselves in swing of the base 11 on which shaft 10 is mounted.

Since the two screens are driven through oppositely set eccentrics, the movements of the two screens, one relatively to the other, continue the same, but the movements of the two screens relatively to the supporting structure vary. By so much as the load upon one screen exceeds the load upon the other, the oscillation of the more heavily loaded screen is diminished, relatively to the supporting structure, and the oscillation of the less heavily loaded screen is increased. The throw of the connecting rods is always the same, but with each rotation the supporting base 11 swings, with the consequence that theefiective strokes of the two rods are of unequal length (relatively to the supporting structure). The platform ii is preferably of considerable massa mass comparable with the loads which the screens have to carry; and, proportionately as the mass of the platform is increased, the varia tions in the ranges of oscillation of the two screens (relatively to the fixed supporting structime) are diminished.

It remains to consider various ways in. which the shaft is may be continuously rotated. Ln Fig.

I, I show the shaft iii to be couipped witha pul- 59 ley 14, and I indicate in full lines 15 a belt by which shaft is may be driven from a power shaft 16 rigidly mounted in the structure of the buiiding. shaft is vertically aligned with shaft l9, and shaft its her diagrammatically indicated by a roller 20, which-* may be understood to be weighted.

In Fig. II the power shaft 21 is shown to be mounted on theplatform 11, and it will be understood that, together with the power shaft the motor also that drives it may be mounted on the platform. I

In Fig. III a flexible connection 22 is shown, through which the shaft 10 upon platform 11 may be driven from a power shaft 12 rigidly mounted in the foundation 24.

Springs 25 which have bearing in a foundation 26 and which engage platform 11 have snubbing effect, to limit maximum travel of the platform.

The specific arrangement illustrated in Figs. V-VII includes the two screens 1 and. 2, as before. The eccentric-equipped shaft 10 is, in this case, mounted, not on a swinging platform, but on a firm foundation 27. A shaft 28, hung on links 29, is an intermediate member, between shaft 10 and screens 1 and 2, and this intermediate member, by its capacity of swinging accomplishes the effect already described. Shaft 28 constitutes a fulcrum pinfor two sets of levers. The levers of one set are connected at one end to one set of eccentric disks upon shaft 10, and the levers of the other set are similarly connected to the other set of eccentric disks upon shaft 10. The two sets of levers at their opposite ends are connected, one set by rods 6 to screen 1, and the other set by rods 7 to screen 2. Rotation of shaft 10 effects oscillation of screens 1 and 2. The two sets of eccentric disks and the two sets of levers are so relatively placed that the oscillatory movements of the two screens are simultaneous and opposite in direction; and, on principles already explained, changes in the relative masses of the two loaded screens 1 and 2 will express themselves in shifting of the shaft 28 and a corresponding change in the relative ranges of swing of the two sets of levers 30 and 31. So long as the loads upon the two screens are equal, the shaft 28 hangs on vertical links 29; but in case of unbalance of the loads, compensation is afforded by a swing of shaft 28 with each rotacombination of a supporting structure, two oscillatory members independently from said structure and capable by virtue of such suspension of being oscillated, a driving member in dependently suspended from a support and by virtue of such suspension capable of oscillation in such support, means arranged between said driving member and each of said oscillatory members through which means the power of the driving member is simultaneously applied in opposite directions to the two said oscillatory members, whereby the resistances of the two members to oscillation are brought into counterpoise and means for driving said driving member.

2. In power-driven oscillatory apparatus the combination of a supporting structure, two oscillatory members independently suspended from said structure and capable by virtue of such suspension of being oscillated, a shaft independently suspended from the said supporting structure and movable in the direction of oscillation of the said members, two levers fulcrumed on the said shaft, separate connections between the two levers and the two oscillatory members, a second shaft rotatably mounted in said supporting structure in parallelism to the shaft first named, and means for oscillating said levers simultaneously in opposite directions in response to rotation of the second-named shaft.

3. In power-driven oscillatory apparatus, the combination of a supporting structure, two oscillatory members, a shaft borne by the said supporting structure and movable in the direction of oscillation of the said members, two levers fulcrumed on said shaft, separate connections between the two levers and the two oscillatory members, a second shaft rotatably mounted in' said supporting structure in parallelism to the shaft first named, means for oscillating said levers simultaneously in opposite directions in response to rotation of the second named shaft, and means for limiting the range of movement of the shaft first named in such direction of oscillation.

4. In power-driven oscillatory apparatus, the combination of a supporting structure, two oscillatory members independently suspended from said structure and capable by virtue of such suspension of being oscillated, a platform independeritly suspended from a support and by virtue of such suspension capable of oscillation iii-such support, a shaft 'rotatably mounted on said plat forirn the mass of the platform with its burden being comparable with that of the oscillatory members first named severally with their loads,

means arranged between the said shaft and each brought into counter-poise, and means for rotating said. shaft.

JAMES w. MURRY.

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