US1952574A - Centrifugal treating machine - Google Patents

Description

Mmh 27, 1934. A, H ADAMS 1,952,574

CENTRIFUGAL TREATING MACHINE Original Filed April 13. 1928 2 Sheets-Sheet 1 #M g l ATTORNEY March 27, 1934. A, H, ADAMS 1,952,574

CENTRIFUGAL TREATING MACHINE original Filed April 13, 192s 2 sheets-sheet 2 Patented Mar. 27, 1934 PATENT OFFICE CENTRIFUGAL TREATIN G MACHINE Arthur l-I. Adams, New York, N. Y.

Original application April 13, 1928, Serial No.

269,851. Divided and this application November 17, 1930. Serial No. 496,358

8 Claims.

This invention relates to Icentrifugal treating machines, and in particular to extractors.

In machines of the above-noted character various arrangements have been proposed for overcoming the deleterious effects due to centrifugal unbalance. For example, in one type of extractor, i. e., the overdriven type, the extractor. basket is attached to the lower end of a relatively long vertical shaft which, with the supports for the 10 upper bearing and drive, interfere materially with the charging of the basket with materials and also makes this construction costly. In this construction gravity tends to bring the shaft to a true vertical and the basket is usuallyA rigidly attached to the shaft, or is otherwise so mounted that a displacement of the shaft from the vertical will tip the basket. When, therefore, the basket is unbalanced by the load and the driving torsion is applied, the tendency of the mass to revolve about the center of gravity-causes the shaft and basket to swing out of the central position,

tipping the basket. This tipping gives rise to a the shaft will only result in what may be calleda normal precession of the shaft axis and of the basket. If, however, the basket is unbalanced, i. e., if its center of mass does not coincide with the geometrical center 'of the shaft which is the usual case. this precessional motion of thef'shaft axis will be irregular and will vary Within wide limits, especially while the basket is coming up to speed. This irregular precessional motion appears in the'form of undesirable vibration of the basket, which may cause the basket to strike the guard or curb and it may even be so violent as to be dangerous toattendants.

In accordance with the present invention undesired vibration is avoided by allowing the basket automatically and speedily to assume, without restraint,'a position n which it may rotate freely about the vertical axis through its center of mass. Further, all precessional motion is made impossible by confining the movement of each particle of the rotating mass to a plane normal to thatner of coupling a rotating element with a driving device in accordance with the disclosure of my The principal object of the invention is to` provide a centrifugal treating machine preferably vof the underdriven type in which the effects of unbalance and of incorrect starting position, are reduced to a minimum. 60

Another object is to provide a centrifugal treating machine wherein the rotating element is laterally unrestrained and therefore free automatically to assume a position of free rotation about an axis through its center of mass, and wherein it is confined to motion in a plane and not subject to precessional disturbances.

Another object is to provide a centrifugal treating machine having means for applying substantially pure torque to the rotating element.

A further object resides in a basket for a centrifugal machine which is mounted for substantially unrestrained motion in a horizontal plane.

A feature of the invention pertains to the manshaft, whereby said element is capable of unrestrained movement in a plane at right angles to the said shaft.

Another feature resides in the combination of a rotating platform with an Aextractor basket mounted on, and adapted to rotate at the 4same angular velocity with, said platform and also capable of simultaneous lateral movement on said platform with a minimum of friction.

A further feature resides in a modified form of universal coupling for transmitting substantially pure torque to an extractor basket.

A further feature ofthe invention relates to novel means for centrifugally balancing a rotating element.

A still further feature is concerned with covercontrolled means for centering an extractor basket with respect to a ldriving shaft.

Other features and advantages of theinvention which have not been specifically enumerated will become apparent after a consideration of the following detailed description and the" appended claims.

While it has been chosen to'disclosev the inventive idea in connection with a centrifugal machine of specific construction, suitable for use as a laundry extractor, it is understood that this is merely for the purpose of description in order that a clear understanding may beattained of one particular mode of practising the invention, and applications to other types of machines are within the compass of the invention.

Referring to the drawings, which show my co-pending application, Serial No. 269,851, filed April 13, 1928, of which this application is a division.

Fig. 1 shows a view in sectional elevation of a machine embodying the various features of the invention;

Fig. 2 shows a plan view in section of apart of the machine of Fig. 1, the section being taken along line 2 2 of Fig. 1;

Fig. 3 is a detail view of one of the basket supporting members;

Figs. 4 and 5 are detail views of one of the pinslot universal couplingv members;

Fig. 6 shows another embodiment of the invention employing an alternative form of frictional basket support;

Fig. 7 is a detail plan view of the anti-frictional basket supporting member shown in the embodiment of Fig. 6;

Fig. 8 is an enlarged view of a section of the member shown in Fig. 7;

Fig. 9 is a detailed view illustrating rthe relation between the driving platform and the frictionless support of Fig. 6 and showing particularly a means to restrain the basket carrier 5 against vertical movement while allowing ample freedom in one plane.

The machine in connection with which it has been chosen to illustrate the invention is generlcally known as a centrifugal extractor and comprises a curb or outer casing l (Fig. l) having a top opening 2 adapted to be closed when the machine is in operation by a suitable cover preferably divided in half and hinged at opposite sides of the curb as represented by the numerals 3,'for purposes hereinafter described. The lower portion of the curb is in the form of a hollow pedestal and serves as a housing for the driving gears, clutch mechanism and other portions of the machine. The opening 2 in the curb is preferably sufficiently large to permit the extractor basket 4 to be raised and lowered on o the carrier 5. As shown in Fig. 1. the basket! has a reentrant central portion of the same gen ral shape as, and adapted to t over, the carrier 5 which is antifrictionally mounted upon the rotating-platform 'rotating carrier and basket for purposes hereinafter described. The reentrant portion of the basket 4 is unperforated While the side walls are copiously perforated for the ejection of liquid or other extract thrown vfrom the materials under treatment. As indicated by the numeral 7 the basket is provided at its center with a hook or its equivalent, by means of which t-he basket may 'Ihis feature of having the basket removable is` highly desirable in machines that are employed las laundry driers, since it permits the basket to be transported on overhead conveyorsor the like and the attendant may more evenly distribute the load in the basket while it is suspended by the hook 7 outside the curb at the appropriate loading station. Any form of. coupling may be provided between the carrier 5 and the basket 4. For example, the raised central portion of the carrier 5 may be provided with a square hole which registers with a corresponding square projection 8 on thecenter of the basket.

anti--V structure for the retention of a layer of oil or other lubricant and also acts as a ring for preventing the extracted liquid from gaining access to the platform proper. Platform 6 is secured to shaft 9 for rotation therewith, said shaft being provided at its lower extremity with a suitable non-frictional step-bearing represented schematically by the numeral 10. It will be understood that platform 6 must preferably spin in a quite truly horizontal plane. be desirable to provide adjustable connections between shaft 9 and platform 6, whereby the said platform may be permanently and accurately fastened to enable it to rotate in a true horizontal plane.

The numeral 11 represents the motor driving shaft which transmits its power to shaft 9 through helical gears 12 and 13. Suitably supported on the interior of the hollow pedestal portion 14 of the ,curb is a box 15 which encloses a braking mechanism for shaft 9. This brake comprises alternate circular discs 16 which are splined to shaft 9, and discs 17 which loosely engage said shaft. Between these sets of discs 16 and 17 are thin sheets of friction material 17. The pressure between the discs and consequently their friction may be regulated by suitable adjusting means schematically represented by the compression spring 18 and the adjusting nut 19.

As shown clearly in Fig. 1, the entire weight of the basket 4 and carrier 5 is anti-frictionally supported on platform 6, preferably at diametrically opposite points on ball-bearing casters 27, or the like, one of which is shown in detail in Fig. 3. Each caster (Fig. 3) comprises a spherical bearing member 28 which rotates in the housing 29 and is backed by balls 30 which are enclosed by the cover 31 through which the member 28 protrudes. The leg 32 which is preferably formed integral with the housing 29 is fastened by appropriate means, as by rivets, to the bottom of the carrier 5. Thus, carrier 5 and the charged basket 4 being anti-frictionally supported are free to move in any direction on the platform 6. For the purpose of transmitting the rotary motion of shaft 9 to the basket 4 without interfering with the free translational movement of said basket ori the platform 6, that is-to say, for applying a substantially pure torque to the basket, there is provided a novely form of an extensible shaft having universal connections atv opposite ends with the platform 6 and the carrier 5 so that said carrier 5 is free to move relative to the platform 4 at the same time that itis being rotated. For this purpose the platform 6 is coupled to the carrier 5 by universal coupling members, one of which is shown in detail in Figs. 4 and 5. This coupling member comreadily be raised and lowered on to the carrier 5.

prisesv a hollow cylindrical member 33 having two slots 34 at opposite sides thereof, which are adapted to receive pins35 formed integrally with the spherical end 36 of the member 37. The slots 34 in the member 33 are sumciently long to permit the member 37 tovmove freely'in a vertical direction. Due to the length of the slots 34 which engagerthe pins 36 as Well as the ball and socket arrangement between the end 36 and member 33,

For this purpose it may f the member 37 is capable, during rotation, of i universal movement Ywith respect to the member 33. lA similar universal coupling is provided be both ends of the shaft 37, when the platform 6 is rotated a corresponding angular velocity is transmitted to the carrier 5 and the loaded basket 4 through the shaft 37, which is free to assume substantially any angular position with relation to the driving shaft 9. In other words, pure torque may be transmitted from the shaft 9 to the carrier 5 regardless of the position of the said carrier and basket on the platform 6. It is obvious therefore that should the load in the basket 4 be unevenly distributed, whereby the center of mass of the rotating system as a whole is displaced laterally with respect to the center of shaft 9, because of the anti-'frictional mounting of the carrier and basket and because of the universal coupling between the platform 6 and the carrier 5 the drum is enabled to start rotation at once about some vertical axis without any substantial restraint, and the position of this vertical axis is determined by the location of the center of the mass at the time of applying torque. This results from the fact that the member 37, while it is capable of transmitting torque to the loaded basket and of rotationally accelerating the mass is incapable of exerting any but an extremely small lateral or translational force on the mass. Thus, the charged basket is free, within certain wide limits, to spin about any point on the platform 6 when it is being rotated by the member 37. In this connection it will be noted that the entire weight of the carrier and loaded basket is borne entirely by the anti-friction members 27 and not by the universal coupling members.

For the purpose of automatically reducing the eccentricity between the center of mass of the system comprising the rotating basket and carrier, and the geometrical center of said system, the carrier 5 is provided with a. novel form of centrifugal balancing arrangement comprising an annular pipe or tube 40 fastened to the outer rim of the carrier 5 in any suitable manner. The tube 40 contains a `quantity of fiowable material preferably of a heavy character such as mercury, mercury amalgam, steel balls, or the like.` Consequently, if the center of mass of the charged basket is eccentric, the flow of material in the tube 40, due to centrifugal force, will tendto move it the greatest possible distance from the center of mass of the rotating system. For example, if the basket 4 shown in Fig. 1, is so loaded that the center of mass is displaced to the right,

then it will start rotating about this center of mass and the portion of the basket and of pipe 40 that was initially `at the left, will be at a greater distance from the center of rotation than any other side. Consequently, the material in tube 40 will tend to accumulate in this initially left-hand portion thereof, which, in effect, causes a gradual displacement of the center of mass of the entire system toward the left until the eccentricity is a minimum. This, of course, does not shift, relative to the earth, the position of the center that the mass spins about. The quantity of material in the tube 40 and the size of said tube may be so designed that the maximum displacement of the center of mass of the rotating system as found in practice may be very nearly counteroalanced. For the purpose of causing the material in tube 40 to move steadily and not too violently toward the unbalanced side of the rotating system, that is, to prevent surges in the flow of material due to acceleration ofthe basket and carrier and to prevent sudden changes in the center of mass of the system, the interior of the tube 40, as indicated by the numeral 41, is provided at various points with baflie plates, gratings, perforated plates, or the like, for the purpose of dampening out such surges of the column of flowing material.

A typical operation of the machine is" as follows:

The basket 4 having been previously removed by suitable conveying mechanism, preferably of the overhead trolley type, is charged as evenly as possible. For this purpose special balancing means may be provided if desired, or it may be loaded or readjusted while suspended in order that the attendant may most accurately distribute the material uniformly about the geometric center of the basket. When the basket has been thus charged it is conveyed from the charging location to the extractor and lowered through the opening 2, and rotated by hand until the pro jection 6 of the basket registers with the correspending hole in the carrier 5. The attendant thereupon closes both halves 42 and 43 of the curb cover. In this connection it will be noted thatevery time the covers are opened the basket is mechanically centered within the curb. This '100 is effected through the intermediary of the centering fingers 44, which move in unison with the respective cover members 42 and 43. When the covers are closed fingers 44 assume the positions shown in full lines in Fig. .1. As the covers are raised the ngers move through corresponding openings 45 in the side of the curb until said fingers engage the sides of the basket 4, as represented by the dotted line positions. Suitable stops 46 are provided to limit the inward movement of the fingers 44 in which position the basket is accurately centered on the platform 6. While` only two centering fingers at diametrically opposite points are shown, it will be understood that two or more may be provided for each half of the cover, the essential thing being that the raising and lowering of the cover causes the basket to be pushed to the center of platform 6. If an electric motor is used, the switch for turning on the motor at the same time energizes the solenoid 26 whereby the frame '22 is drawn out'of engagement with the clutch discs 17 which are thereupon free to rotate with the shaft 9 which in turn rotates the platform 6. When shaft 9 rotates a torque is transmitted through the member 37 to the basket and carrier which are therefore constrained to rotate at the same angular velocity as the .shaft 9. If the basket is accurately balanced initially, and since it started geometrically centered over the center of shaft 9, it is obvious that the center of the mass will be substantially in line with the axis of the shaft 9. Consequently when torque is transmitted through the member 37 the platform 5 with the basket 4 will find its natural center of rotation to be sub- 135 stantially in line with shaft 9 and will rotate resting on the platform 6 without any motion relative to said platform. The material in the tube 40 will have been symmetrically distributed in the tube by gravity and will not shift.

Obviously center over'platform 6: moreover, if the basket il;

translatory inertial resistance increases,v relative to rotational, permitting higher friction to be overcome using the same or less torque. This will have the effect of causing every point of the basket and carrier and the anti-friction supporting members 27 (Fig. 3), in particular, to deg scribe circles over the surface of platform 6. These circles will al1 have the same radius and this radius will be equal to the displacement of the center'of mass from the center of the ma chine. The action will be much like that of rubbing the two hands together with a simultaneous circular movement.

Due to the balancing effect of the material in tube 40, the eccentricity of the center of mass in the basket is progressively decreased by the material in said tube tending to move in a direction opposite to the displacement of the' center of 'mass Since the basket and carrier forma closed system incapable of receiving any translational force, this will not, as vmight at first be supposed, bring the center of mass any near'er the axis of shaft 9, but merely reduces the eccentricity of the basket.

Of course the optimum counterbalancing condition would be attained if the material in'tube 40 'could entirely counterbalance the unbalanced load and if the center of mass could thus be brought absolutely to coincide with the center of the basket.

Further, it is desirable that the nal center of mass (and of rotation) of the basket, even though toone side o f the geometric center of the basket, should be brought to the center of the machine. For in this condition the handrubbing movement'of the support 5 and of the basket relative to platform 6 will cease entirely.

While the center of mass, because of the lack of all constraint, will not be driven farther from the centerof the machine by centrifugal force, there are only very weak forces (such as the' greater air pressureon the basket at any side where it runs nearer the curb) to impel it to the machine center. A slight tilt of platform 6 might cause gravity to overcome this air force. Hence,

it'has been found advisable to supply a set of light centering springs 47, 48, weakly tending to locate carrier 5 with its center over the axis of shaft 9.

These should be relatively weak in order not to provide suiiicient lateral constraint to the self-centering action of the basket to cause it to develop appreciable centrifugal force. It is clear that, were these springs strong, they would hold the geometric center of the basket on the machine center, regardless of the position of the center of mass. The universal jointed coupling member 37 would still force the basket to spin, but the center of mass of the basket would be forced to revolve (relative to the earth) about the center of the machine, instead of remaining stationary (relative to the earth) l as through inertia it tends to do, and as it is the great advantage of this invention to permit it to do. A set of lightsprings, especially if connected, as shown on a slant,A will not give constraint enough to compel the center of mass to revolve and yet will slowly draw basket and carrier 5 as near as possible to their centering on the :machine center. When the center of mass of the basket'is over the machine center these springs are as nearly satisfied as possible and no further relative movement will occur between carrier tandsupport 6.

is centrally weighted as suggested (page 2), s After the extraction is completed, the motive power is turned o ff causing a deenergization of the solenoid 26 and a retraction of the frame 22 into engagement with the clutch discs 17. The frame 22 thereupon grips the next set of pro jections 21, for example, and positively prevents further rotation of the driving discs 17. The

shaft 9 is therefore subjected to a continuous braking action.

While a specific form` of extensible universal coupling is provided between the carrier 5 and the platform 6, it will be obvious that any other form may be employed. For example, instead of relying upon the slots 34 for permitting the lateral movement of the basket, the shaft 3'? may be of the telescoping kind and well known forms of universal couplings may be provided between the two ends of the telescoping shaft and the support 5 and platform 6 respectively.

Referring to Fig. 6, there is shown another modification of the invention in which the basket -4 instead of being mounted on ball-bearing casters is mounted on a ball bearing thrust ring comprising a circular sheet of metal 49 (Fig. 7) having a series of balls 50, rotatably mounted in corresponding perforations in the plate 49. Any well known manner of mounting the balls in the plate, to enable the balls to freely move without dislodgment, may be employed. For eX- ample, the surfaces of the plate may be punched, as indicated by the numeral 51, to retain the balls therein. As shown in Fig. 6, the carrier 5 is coupled to the rotating platform 6 by an extensible universal coupling member 37 so that when member 37 is moved angularly with respect to the driving shaft 9, the plate 49 also moves to correspond, but to just half the extent. This would be the natural movement of plate 49 if carried by the perfect rolling of balls 48. This coupling of plate 49 to member 37 at onehalf the height of the latter serves to counteract any tendency of the latter to slip or creep.

' For the purpose of limiting any possible vertical displacement of the basket 4, the same is provided with downwardly projecting pins 53 (Fig. 9) which pass through relatively large openings 54' and 55 in the members 49 and 6 respectively. The pins 53 carry at their lower ends members 56 which are larger than the openings 55. so that the vertical movement of carrier `5 is limited. Since basket 4 and platform 6 rotate with the same velocity, this limiting arrangement does not interfere with the free movement of the basket on the platform. It will be understood that the platform 6 has oil for reducing the friction between the member`49 and the said platform. The remaining parts of the machine shown in Fig. 6 may be similar to those disclosed in connection with Fig. 1 and it is believed 'that the operation of this embodiment of the machine will be understood from the description given hereinabove. In this connection it may be noted that the embodiment treating machine having a basket or container* which is substantially free to revolve about its center of mass without undesirable vibration.

What I claim is:

1. In a centrifugal treating machine, a rotating platform, a drum carrier anti-:frictional means mounted on said carrier to support said carrier on said platform, means constraining said carrier to move at the same angular velocity as said platform without otherwise restraining the freedom of movement of said carrier on said platform.

2. In a centrifugal treating machine, a vertical driving shaft, a platform, a basket antifrictionally mounted on said platform, and a coupling member universally -connected at opposite ends to said shaft and said basket respectively.

3. In a centrifugal treating machine, a basket substantially free translationally in one plane only, and means to apply to said basket .a substantially pure turning movement in said plane.

4. Ina centrifugal treating machine, a horizontal table, a rotating vertical shaft, a basket, anti-friction bearings supporting said basket and permitting free movement of said basket over said table in any direction, and means including said shaft for imparting to said basket solely a turning movement.

5. In a centrifugal treating machine, a basket mounted for substantially unrestrained movement in a plane, means for applying substantially pure torque to said'basket whereby it rotates around its centerl of mass, and means to autodriving shaft for driving said platform, a second shaft for rotating said basket with said platform,

said second-named shaft comprising an extensible universal coupling between said basket andL said platform.

7. In a centrifugal extractor of the underdriven type, a platform, a basket, anti-frictional means supporting said basket on said platform, a driving shaft for driving said platform, a second shaft for rotating said basket with said platform, said second-named shaft comprising an 'extensible universal coupling between said basket and said platform, and symmetrically arranged resilient means connecting said platform and basket, whereby any tendency of said basket for precessional movement is substantially inhibited.

8. In a centrifugal treating machine, a rotor that may be unbalancedly loaded with material, means substantially to constrain said rotor to movements in a gravitationally equipotential plane, antifrictional means to minimize all frictional restraint on said rotor in that plane, means to apply to said rotor a strong purely rotational force substantially about an axis normal to that plane, and a very light centering device to prevent said rotor from slowly wandering in that plane.

ARTHUR H. ADAMS.

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