US2932401A

US2932401A - Suspended centrifugal apparatus

Info

Publication number: US2932401A
Application number: US665564A
Authority: US
Inventors: David M Tholl
Original assignee: American Tool & Machine Compan
Current assignee: American Tool & Machine Co; American Tool & Machine Compan
Priority date: 1957-06-13
Filing date: 1957-06-13
Publication date: 1960-04-12
Anticipated expiration: 1977-04-12

Description

April 12, 1960 D. M. THOLL SUSPENDED CENTRIFUGAL APPARATUS 3 Sheets-Sheet 1 Filed June 13, 1957 April 12, 960 D. M. THOLL 2,932,401

USPENDED CENTRIFUGAL APPARATUS Filed June 13, 1957 3 Sheets-Sheet 2 ll i l 5? 42 i 71 x 6 I 8 I 7 I I 1 L i I L i Z0 1 f 2 i i l' v A; H I I I, i

lnveaaiow PM me L l l i I SUSPENDED CENTRIFUGAL APPARATUS David M. Tholl, Needham, Mass., assignor to American Tool & Machine Company, Boston, Mass, a corporation of Massachusetts Application June 13, 1957, Serial No. 665,564

6 Claims. (Cl. 210-369) This invention relates to a suspension type centrifugal for use in centrifugally separating fluid from various materials and, in particular, the invention is concerned with a centrifugal for removing washwater from relatively light, bulky products such as leafy vegetables and the like.

In dealing with a product such as leafy vegetables, and

nited States Fatent O V which a fluid may be expelled when the basket load is subjected to centrifugal forces.

At its upper side, the basket is open to admit material to be centrifuged which may, for example, be delivered from a conveyor member 24 (Fig. 1).

In accordance with the best form of the invention, 1

7 provide in the basket 22 a special adjustable bottom in particular spinach, the need is for a type of centrifugal which can quickly and cheaply carry out a separation of wash water from the spinach and then discharge the centrifuged product with a minimum of interference or sticking of the washed product to the basket. In addition, it is important to provide a type of discharge which can be used eifectively with automatic control means as well as loading and discharge conveyor devices.

To meet these requirements, I have devised a centrifugal construction which is based on the novel concept of combining a centrifugally driven basket with a vertically adjustable bottom mechanism and supporting both these structures from a suspension drive which revolves about a vertically adjustable axis. I have discovered that this novel concept may be practically realized by utilizing .a telescopic arrangement of parts whereby a conical bot- .tom element and lift rod is adapted to move into a lowered discharge position in response to forces of gravity. .However, when actuated by a positive fluid pressure, the .conical bottom and lift rod may be raised into a closed .or sealed position. An immediate advantage which is derived from this type of assembly is that both the cenatrifugal drive for the basket and the actuating means for producing fluid pressure can be mounted in a common supporting structure at the top of the centrifugal machine frame.

These and other objects, novel features and advantages will be more fully understood and appreciated from the following description of preferred embodiments of the invention selected for purposes of illustration and shown in the accompanying drawings in which:

Fig. l is a view in front elevation of the centrifugal of the invention illustrating the basket and vertically movable bottom in closed relation to one another and further indicating in dotted lines the bottom lowered into a discharge position;

Fig. 2 is a view in side elevation of the structure shown in Fig. 1;

Fig. 3 is a detail cross-sectional view; and

Fig. 4 is an enlarged vertical cross-sectional view of the suspension drive and the actuating means for raising and lowering the basket.

Referring more in detail to the drawings, numerals 2 and 4 indicate upright members of one suitable frame structure of the invention. At the upper side of this frame structure are transversely extending channel members as 6 and 8 bolted together and resting on other channel members as 10, 11, 12 and 13. At intermediate portions of the upright'members 2 and 4 are secured angle brackets as 14 and 16, as shown in Fig. 1,

section which can be dropped down to furnish a discharge outlet. This bottom section preferably consists of a conically shaped member 26, such as. that shown in Fig. 1. This conically shaped member is constructed at its lower side with a beveled seating surface adapted to seat against an upturned edge 27 which is formed at the lower edge of the basket 22.

In combination with this movable bottom section 26, I further provide a special actuating device for raising and lowering this conical bottom section 26. An unusual feature of the actuating device is that it is designed to form a part of a suspension drive mechanism shown on an enlarged scale in Fig. 4. An important element of the actuating device is a lift rod element 28 which, at its lower end, is connected to the top of the conically shaped member, as shown in Fig. 1.

In a preferred form of the invention, I mount the lift rod 28 in telescoping relationship within a tubular drive shaft element 32 of the suspension drive mechanism. The upper portion of the lift rod passes through a tubular shaft extension 32a and extends into the bore 34 of a pulley 38 fixed on the element 32a, as suggested in Fig. 4. Threaded or otherwise secured to the upper end of the lift rod 28 is a piston rod 38 carrying a plunger 40. The plunger 40 is mounted in sealing relationship within a cylinder 42 which is bolted to the upper side of the pulley 36 on a suitable base plate 44.

By means of the arrangements of parts described, it

. will be apparent that the lift rod and conical bottom 26 are free to drop downwardly in response to forces of gravity into the broken line position indicated in Fig. 1. To raise the unit,'in accordance with the invention, there is provided at the bottom of the cylinder 42 a tubular conduit 48 connected through the side wall of this member. The upper end of the tubular conduit 48 is also connected to an air supply conduit 50 by means of a suitable fitting and compressed air is delivered through a rotary sealerunit 52 and mounting pipes 54 and 56 from a source controlled by a conventional type four-way air valve unit 54.

When the air valve is opened at a desired point, air or other compressed fluid flows through the member 48 into the bottom of a closed space in the cylinder 42 and the piston is forced upwardly into the position shown in Fig. 4, carrying the conical bottom 26 into sealed relationship to the bottom of the basket 22. To facilitate this movement of the piston and release of air, I may provide a bleeder valve 60 at the rupper end of cylinder 42 (Fig. 4). As earlier noted, an important feature of the conical bottom section 26 and the actuating device above described is its attachment to the suspension drive so that it may revolve with the tubular drive shaft when the latter is rotated.

As shown in Fig. 4, the tubular extension 32a is provided with cupped bearing means 62 mounted in a bearing plate 64 bolted to the transverse frame members 6. Threaded expansion member 66 is tightly engaged against a sealing member 68 which rests against conical seat 76'. A motor 72 actuates pulleys 76 through a reduction gear mechanism 74 to drive the pulley and shaft 32 which in turn drives the basket together with the conical bottom section and lift rod.

It is pointed out that, by means of this arrangement, the basket may be driven at varying speeds and at any desired point, the conical bottom may be raised or lowered as required while the machine is running. I may, in this connection, also employ a standard type of air braking mechanism indicated in the drawings at 78 for releasing or tightening a brake band element 80 located around a brake drum portion 82 fast on the tubular member 32.

The braking mechanism may be actuated automatically by means of a conventional air cylinder or other suitable control.

As shown in Fig. 1, material may be delivered to the basket from the conveyor 24. A second conveyor 84 is located in a suitable position below the basket to receive and carry away centrifuged material which is discharged from the basket when the conical bottom section 26 is allowed to drop into its lowermost position. A hopper 86 with a converging bottom aperture may be employed to guide the discharged material on to the conveyor 84.

In the case of certain types of materials it may also be desired to provide means for mechanically scraping the inner peripheral surface of the basket 22 in order to dislodge material collecting thereon. As one suitable means of accomplishing this, I have combined with the movable bottom section 26 described above a special discharger shoe 90 which, as shown in Fig. 1, may be supported on uprights 92 and 94 fixed to the bottom section. This discharger shoe is of annular form and presents a rolled edge adapted to lightly engage against the basket periphery around the top thereof and, when the conical bottom 26 is allowed to drop downwards, the discharger shoe also drops and carries with it collected material. If desired, I may also use compressed air or other fluid to positively force the scraper downwardly.

In a typical operating cycle, the air cylinder is actuated to raise the conical section 26 into a sealed position and the basket is rotatably driven to bring it up to a speed of about rpm. The basket is held at this speed for a short interval to provide for loading. Thereafter, the basket speed is increased to a predetermined proper extracting speed and continued at this speed while centrifuging is carried out. Thereafter, the power is cut off automatically and the brake applied and the conical bottom section 26 is allowed to drop down to permit discharge of the centrifuged material which is automatically conveyed to a desired point. If desired, the air operated piston may be positively forced down in some cases.

It is again pointed out that the lift rod and conical bottom section, together with the basket 22 and cylinder 42, all revolve as a single unit during the centrifuging cycle with the tubular member 50 revolving in the rotary sealing unit 52 in the well-known manner. It will be evident that, by thus driving the basket with a suspension drive and allowing the conical bottom to be raised and lowered through this suspension drive, it becomes possible to eliminate separate actuating mechanisms at points below the basket and this, in turn, facilitates the use of a discharge and conveyor for centrifuged material. It will also be seen that, by the telescoping arrangement of parts described, the use of automation is greatly facilitated and the entire loading cycle, centrifuging cycle'and discharge cycle may all be set to operate automatically in a desired sequence with a single control agency. Moreover, a simplified construction is made possible with a much smaller number of parts being necessary.

It will be understood that various changes and modifications may be resorted to within the scope of the appended claims.

Having thus described my invention, what I claim is:

1. An improved centrifugal comprising a frame having a curb supported thereon, a suspension drive mechanism, including a tubular drive shaft and concentrically located lifting means, a cylindrical basket element fixed to the lower end of the tubular drive shaft, said cylindrical basket having a vertically adjustable conical bottom attached to the lifting means, said conical bottom having a diameter at least equal to the inner diameter of the basket, power driven means for rotating said tubular drive mechanism and basket thereby to compress an annular mass of centrifuged material into adhering relationship with respect to the inner peripheral surface of the basket, and said lifting means being axially displaceable in said drive mechanism for lowering the vertically adjustable conical bottom out of seated relationship with respect to the basket to define an unobstructed cylindrical aperture of the same diameter as the inner diameter of the basket whereby the adhering annular mass of centrifuged material is free to drop away from the basket without interference.

2. A structure as defined in claim 1 in which the axially displaceable lifting means includes a cylinder, a piston and piston rod mounted for reciprocating movement in the cylinder, said piston rod at its lower end being connected to the vertically adjustable bottom, and fluid pressure means for acting on the piston and raising the vertically displaceable bottom into seated relationship when the basket is to be employed in holding a material to be centrifuged.

3. A structure according to claim 2 including a source of compressed fluid, a rotary sealer unit and a conduit element connected between the source of compressed fluid and the said piston and cylinder whereby the latter elements are supported for rotation with the basket.

4. A structure according to claim 3 including discha'rger shoe means attached to the adjustable bottom for dislodg'ing material from the basket.

5. A structure according to claim 1 including vertical supporting arms fixed to the adjustable bottom and an annular discharger element mounted on the supporting arms in a position to engage and remove material from the inner periphery of the basket.

6. A structure according to claim 1 including air cylinder means for automatically controlling the axially displaceable means.

References Cited in the file of this patent UNITED STATES PATENTS