USRE8488E - Improvement in self-balancing centrifugal machines - Google Patents

Description

D. M. WESTON.

Reissued Nov. 12,1878.

rIw/Erllny.

Self-.Balancing Centrifugal Machine.

VW// ////.//////////././4. m D| X11. u j v/.// Z. ,C1 N, .e fV/////////////////////, -w A 5 w f E EW W. Q M x W UNITED STATES lPATENT .Orrron navin it wnsrtnv,l or BOSTON, MAssac.i'iesjnrrs- IMPROVEMENT IN SELF-BALANCINGCEN'l'lilFUGL MACHINES.

Spi-einheit ion Ibrniingpai-t of Letters Ihitcnt No. 82,049, dated September 8, 1868; Reissue No. 8,4 SS, dated November 12, 1878 al'iplicatoirlcd November 1, 1878. y l

To all yirl/om' il may concern: i

lle it hnoivn that I, DAVID M. YESTON, of Boston in the' State of Massachusetts, have 'invented a new and useful Improvement-in Sehalancing Centrifugal Machines; and I do herebydeclare that the following is a full, clear, andexact description of the same, reference being had to the accompanying drawings', .making part of this specification, and to the letters of reference marked thereon. The object of this invention is to avoid the injurious effects caused by the irregular or uner i nal distribution of material to be acted upon wi'hin the revolving cylinders of centrifugal ann-ninos, as dcsciibed 'in the schedule an- '1r-ved to thc'reiss'ue of my former patent dated ,flannary 14, 186.5', No. 2,845, but by the ilse of a. d i It'ercnt method; and the invention consists, ah vily, in a centrifugal machine composed of a cylinder or basket-,placed at the upper end of a rotating vertical shaft, sustained in or ein- -inar-ed by a box or'bcaring Aat its lower end only the said-*box being' surrounded by a eX- ible easy-yielding spring, instead of suspending it from a ticxible bearing or connection- :above and attaching the cylinder to its lower f tnih'as heretofore done by me, thus reversing the former method.

" .When an upright shaft in xed bearings is `nnequally'loaded and rotated at high velocity nit tends, to revolve lcccentricall y, and vibratcs 'audio-rs within its bearings, thereby causing great waste of power, and limiting thespeed at which thes'haft may be revolved. To meet this condition of things, it. is necessary that the bearing should have sufticient freedom of motion to'allow thc shaft and its load to find and revolve around the center of gravity of thc rotating mass; that, in -order to permit nach rapid rotation, the spindle should have as little weight as is consistent. with proper strength; that, while the shaft is free to vila-aic when in a vertical position, it shall meet \.i|h al rapidly-inffreasing resistance When'it leaves that position, so as to prevent the shaft from being thrown into gyrations, and so as to compel it to revolve as nearly yas may bc about its center of gravity; and that the bearing shall be connected with its tixed support Division A.

by means of some flexible or elastic medium,

which, by virtue ofy its elasticity, will pci-mit the necessary movement of the bearing without making and breaking its contact with its support or `with the shaft, .otherwise the rapid succession of such contacts and impacts o t' their surfaces would produce a very objectionable noise and jar, and would soon derange the machine. i

Centrifugal. machines have been niade to revolve upon an upright shaft with a pivotbearing at the bottom;but adifiiculty to be overcome has been found from, their tendency rto staggcr or surge in starting with.' a charge of sugar or other semi-liquid material, which results in a heavy lurch, so grcatas to stop the revolution of the machine..

Irart-ially-tlexible upper bearings have been .applied to the` shaft near and below the cylinder, with a pulley attached between this and thc lower bca-ring, as in the Fesca machine, imported from Berlin. These machines cannot be charged before-starting, and it has been found necessary to charge the cylinder with the material to be acted upon atspecd.

An improvement von this machine has been patented in the United States, enabling the operator to charge the machine while stationary, which improvement consists in the application of an. adjustable fixed bearing applied abovethe cylinder, which is removed after starting and attaining a certain degree ot' speed.' This requires the attention of a skillful operator to detach this adjustable bearing at the top at the proper moment.

1n all centrifugal machines,revolving upon fixed bearings, great weight and strength of machinery are-'required to obtain a proper dcgrec of stability, and revolving as they do at a high speed, 'a very objectionable jar and concussion are produced,

The same (.lifiiculty arises in a proportionate degree by the attempt to control the machine by thelupper ilexible bearings below the cylinder above described.

Figure 1 is a longitudinal sectional view of my invention, with thc rest upon which lthe shaft and box are supported. tion' of Fig. '.l on the line x .r.

Fig. 2 is a scc va shaft or spindle held by an india-rubber tached the cylinder or receptacle a, which conv tai ns the material to be operated upon,

material, placed around the outer circumference of the box d, within a stationary socket securely held upon the cross-timbers g, below wolve, without any support or control to keep as to exercise control over its revolutions in from the center or stagger when starting is Referring, for the sake of comparison, to my patented machine hereinbefore referred to, it will be seen that the cylinder or basket is attached to a hollow shaft, which surrounds bushing or spring, contained within a attached firmly to the frame.

In 'reversing this contrivance I have de-l parted from the construction shown in the former patent, in that, instead of the suspended non-rotating spindle, I have substituted an upright bearing-box, to receive the lower end of the rotating cylinder-shaft, and have atsocket directly to the upper end of the shaft or spindle b, upon which is placed the pulley c, to which the drivingbelt is applied, all bearings above or just below the cylinder being thereby obviated. rlhis shaft b revolves in the box d, suitably held and supported by the flexible easily-yieldin g spring e, made Vof rubber o r other elastic or fixed support, t, which is herein shown as and attached firmly to the lower surface of the floor-timbers h, on which the iloor i rests.

Power being applied by means of a drivin g-4 Hbelt attached to the pulley c below the plat'- 'iorm or floor, the machine commences to' reit in position other than the spring e, which is made softlexible as to have just sulicient strength to preserve the vertical position of 111e machine while stationary, but not so rigid motion. v

The tendency' of the machine to voscillate overcome without difculty by making the upright'shaft of a length not less than one and one-fourth time the diameter of the cylinder, and by the use of the spring c, of the iexiblecharacter above described, at the base.

It isessential that the length of the upright shaft should be such as to permit the naturalV oscillation-:of the machine in starting within such an angle as to keep the cylinder very nearly on a horizontal plane and the shaft nearly perpendicular. i

rlhe naturalv tendency of the machine under as set forth.

sass

these conditions is to find an axis of revolution `in perfect equilibrium.

The pull of the .belt should applied as nearly opposite the box as possible, to thereby reduce fthe tendency of the belt to strain or defleet the shaft from perpendicular position, and

therefore the pulley c is extended down over the box d and the bushing.

It is obvious that a'shaft supported only at its lower end in the manner herein described is practically free, within certain limits, to move bodily in any lateral direction as well as to incline froml a perpendicular, thus being enabled to revolve steadily about the center ofgravity determined by the :unequal distribution of the load upon the shaft.

By supporting the shaft or spindle at its lower end only, its upper end y-is left entirely free to oscillate or vibrate under the'action of an vunequal distribution of its load; the length` of the shaft is less than if supl'iorted at both. ends, thereby reducingits weight; the frictionk of abearing at-the upper end of thc shaft is obviated, and cost ot" mechanism is reduced. The power to rotate the shaft being applied substantially at or near` the bearing at the lower end of the shaftalso permits the upper end ofthe shaft to be leftentirely free and unrestrained.

I claim-r.- 1. In ace'ntrifugal machine, the upright rotary shaft, vsupported at its lower end only,

and the cylinder connected with thc said shaft, combined with the bearing in which the shaft rests and rotates, andthe easily-yieldin g spring outside the box, substantially as and f or the purpose described.

2. The centrifugal cylinder and the upright cylinder-shaft, supported at its lower end only, and made of sufficient length with reference to the diameter of the cylinder, as described,

to prevent the excessive angulaioscillation of the machine, combined with thc support for the said shaft and yielding spring, operating In testimony whereof I have hereunto set my hand and sea-I.

DAVID M. WESTON. 4[1.. s.; llitnesses :i

G. W. Gascon, v j N. E. WHITNEY.

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