US2865507A - Centrifugal drier construction - Google Patents

Description

Dec. 23, 1958 J. G. BRUBACHER CENTRIFUGAL DRIER CONSTRUCTION Filed Nov. 25, 1955 6 3 i Z J W [3 5 7 #2 o Z I! (/V W m. 2 6 I 22 2 g 5. m a

INVENTOR United States Patent 1.

CENTRIFUGAL DRIER CONSTRUCTION Joseph G. Brubacher, Ephrata, Pa., assignor to s perry Rand Corporation, New Holland, Pa., a corporation of Delaware Application November 25, 1955, Serial No. 548,883 2 Claims. (Cl. 210-143) The present invention relates generally to centrifugal driers, and more particularly to centrifugal driers of the type used in drying metal parts. In a still more specific aspect, the invention relates. to a control mechanlsm for such a drier.

After metal parts and the like have been manufactured, it is customary to clean them in a suitable cleaning fluid. It is then desirable to dry the parts promptly so that they will not be subjected to rust or corrosion resulting from the retention of cleaning fluids and so that the parts can be packed for shipment without delay. For this purpose, centrifugal driers are commonly employed.

Such driers generally include a foraminous drying cage into which aperforated basket containing metal parts is placed. The cage is disposed in a housing where it is adapted to be rotated at high speed. The cleaning fluid on the parts is thrown outwardly by centrifugal force as the cage and basket are rotated. The fluid passes through the side walls of the basket and cage and into the housing. The housing is provided with a suitable outlet at a point beneath the bottom of the cage for escape of the fluid. 7

Normally, the cage employed in such a drier is open at the top so that a basket of parts may be readily inserted and removed from the drier. A closure is provided for the top of the cage which is primarily for the purpose of preventing parts in the drier from being thrown from the cage when it is rotating. It is, therefore, an important object of the invention to provide a latch or interlock mechanism, actuated by the control mechanism of this invention, for securing the closure in operating position over the cage while the latter is in operation.

Another object of this invention is to provide a control mechanism for a centrifugal drier which, when actuated while the drier is running, shuts ofl. the drier motor, brakes the rotation of the drier cage and unlocks the drier closure.

Another object of this invention is to provide a centrifugal drier so constructed that the housing, cage and basket of the drier can be quickly and easily removed therefrom.

Another object of this invention is to provide a centrifugal drier having improved brake means for preventing the drier cage from coasting after the drive means of the drier has been shut off.

A further feature encompassed by the present invention includes a control mechanism for the means which drives the drier cage, this control mechanism beingso associated with the latch for the closure as to render the drive means to the cage inoperative upon disengagement of the latch.

A further important object consists in such relative disposition of the latch means and the closure that when the. latter is in open position, it maintains the latch means in disengaged position and functions through the Control mechanism, above mentioned, to prevent the drive 2,865,507. Patented Dec. 23, 1958 ICC means from-operating until the closure is again moved to closed position over the cage.

A still further object of this invention is to provide a centrifugal drier having a control mechanism of simplified design and few parts, thereby making the manufacture of the drier inexpensive in relation to centrifugal driers of prior design.

Other objects of this invention will be apparent here-- inafter from the specification and from the recital in the appended claims.

In the drawing:

Figure 1 is a vertical section through a centrifugal drier constructed according to one embodiment of my invention and illustrating the novel control mechanism therein; and,

Figure 2 is a plan view of the drier.

Referring now in detail to the accompanying drawing, the reference character 10 designates a hollow base having downwardly depending marginal side walls or flanges 11 which seat upon a supporting surface S. Preferably, base 10 is bolted securely to surface S so that the drier will not walk because of vibrations when the drier is used. Mounted on base 10, on the top or horizontal wall 12 thereof, is a vertically extending drier housing 13, preferably of cylindrical conformation. Housing 13 is open at its upper end.

Coaxially disposed in the housing is a cylindrical cage 14 having perforated or foraminous cylindrical sides and a solid bottom 14'. This cage has an opening at its top registering with the opening in the housing, thereby permitting easy insertion or withdrawal of parts from the cage.

Cage 14 is adapted to receive a basket 15 containing metal parts. 'Basket 15 is preferably made of heavy gauge wire screening suitably braced by vertical metal rods, not shown, welded to metal rings 16 at the top and bottom of the basket. Fastened to the under side of basket 15 is a pair of spaced, parallel rods 17. These rods are adapted to engage driving lugs 18 welded, brazed, or otherwise secured to the top surface of bottom 14 of cage 14. Thus, when cage 14 is rotated, basket 15 will move with it without slipping.

A vertical shaft 20, coaxial with the axis of the cylindrical cage 14, is rotatably mounted in a sleeve 21 fixed within the housing 13, as shown, and supported against axial displacement therein in conventional bearings 22 and 23.

Rotation is imparted to the shaft 20 and cage 14 through a driven pulley or sheave 25, fixed on the lower end of shaft 20, through a belt 26 operatively disposed around this sheave and a driving sheave or pulley 27 fixed on the shaft 28 of an electric motor 30, which is vertically mounted on the base 10. Motor 30 is detachably secured to base 10 by bolts or other means, not shown.

In the preferred construction, the housing 13 has a horizontal base 31 which seats on the top 12 of the base 10 over an aperture 32 in said base of sufficient size to permit insertion and retraction therethrough of the driven pulley 25. Base 31 is fastened to top plate 12 by means of bolts 33. It will thus be seen that by re moving bolts 33 the drier assembly per se may be completely and easily lifted from the remainder of the mechanism shown whenever desired, for servicing or repairs, and to permit easy access to the interior of'the' base 10.

The top 12 of base 10 has a second aperture 34 be neath" the supporting plate 35 of motor 30; Aperture 33 is of sufficient'diameter to permit passage of sheave 27 therethrough. Therefore, if motor 30 requires replacement or servicing, it is easily removed from the drier merely by removing the bolts fastening it to base and by lifting it vertically off of top plate 12.

Also, in the illustrated form of drier, the housing 13 is provided with a false bottom 37 which slopes downwardly to an outlet or discharge opening 38, whereby cleaning fluid or liquid from the perforated cage 14 may be discharged to the exterior of the housing 13.

A closure 40 consisting of a downwardly cupped dome portion 41 and a lower flat closure plate 42 normally covers the open upper ends of the cage 14 and housing 13, as indicated. This closure is preferably hollow; and, the top area of dome portion 41 and plate 42 are perforated to permit downward passage of air into the cage 14.

Av series of radial fan blades 43 on the bottom of the cage 14, and rotatable therewith, provide means for drawing air downwardly through the perforated portions 41 and 42 of closure 40, thence through the basket 15, drying cage 14 and outwardly through the perforated cylindrical sides thereof, and then expelling the air through the discharge or outlet opening 38. If desired, the closure may have housed therein suitable electric heating coils 45 whereby the air drawn into and through the drier may be first heated to thereby improve its drying action. Instead of heating coils, steam heating units, or other means, may be used to heat the air passing into the drier.

The cover or closure 40 is moveably supported over the open upper ends of the housing 13 and cage 14 by means comprising a U-shaped bracket 46 fixed on and, in substance, constituting a portion of said closure. The lower horizontal leg 47 of this bracket is preferably coplanar with the lower plate or portion 42 of the closure. A hinge pintle 48 is disposed through registering openings in the bracket 46 and in openings in a similar, somewhat smaller, U-shaped bracket 49 fixed to the side of housing 13. Pintie 48 defines a pivotal axis about which the closure 40 may be swung either to cover the upper ends of housing 13 and cage 14, in the position illustrated, or substantially at 180 to such position to uncover said housing and cage and permit access to the interior of the drier.

Normally the closure 46 is maintained in its closed position by means of a latch or interlock rod 50 which is reciprocally guided adjacent its upper end 51 through bracket 49 for operative reception in a registering opening or slot 52 in the lower horizontal leg 47 of bracket 46. It will thus be seen that the leg 47 constitutes a latch means cooperating with the latch rod 50.

The lower end of rod 50 projects downwardly through the top plate 12 and into the hollow interior of the base 10; and. it is preferably slideably disposed through a guide or hearing 53. A spring 54 disposed under compression about the rod 56* and between the top 12 of base 10 and a collar 55 fixed on rod 50 normally resiliently urges the rod upwardly into the operative position shown, wherein its upper end 51 is operatively received in the aperture 52 in bracket leg 47 of the cover 40. A stop 57 fixed on the rod 50 beneath the guide 53 serves by engagement with said guide to limit the upward movement of the rod 50.

Fulcrurned or pivoted on the lower end of the rod 50 at 64 within the hollow base 10, is a rigid floating lever 61 on which a suitable friction brake disc 62 is pivotally supported or fulcrurned at 63. Brake disc 62 is held against rotary movement.

In order to provide a means for actuating floating lever 61, there is pivotally associated with the end 64 of the lever, at 65, a rigid lever 66 which is medially fulcrumed within the base 10 at 67 and which projects outwardly of the base. Lever 66 is moveable vertically in a slot 68 in a side flange 11 of base 10. The outer or free end 69 of this lever constitutes a convenient foot treadle which is normally urged resiliently upwardly by a spring 70 disposed under tension between the lever 66 and the top plate 12 of base 10, as shown.

It will be seen that the braking disc 62 is adapted for cooperation with the lower axially presented flat face or surface of the driven pulley 25, whereby these two elements 25' and 62 may constitute the cooperating elements of a complete brake mechanism.

Motor is wired in a conventional electrical circuit, there being provided an oif-reverse-forward switch, not shown, for controlling the motor. Preferably, cage 14 is rotated in one direction for a desired period of time, say 30 seconds, and then reversed to run in the opposite direction for a like period. This will insure thorough removal of cleaning fluid on parts placed in the cage.

In order to disrupt the electrical circuit to the driving motor 30 whenever it is desired to open the closure 40, and to thereby insure against rotation of the cage 14 and the accompanying danger of the centrifugal force flinging out the contents of the cage 14, there is provided a microswitch 71, in circuit with the motor 30, and adapted to interrupt such circuit responsive to retraction of the rod 50. To this end the spring-projected plunger 72 of this switch 71, which maintains the circuit through the switch closed when the said plunger 72 is fully projected, is disposed below and in the path of movement of an abutment 73 fixed on the latch rod 50. Therefore, retraction of the latch rod 50 sufliciently to disengage itsv upper end 51 from the locking recess 52 in leg 47 in the bracket 46 of the cover will depress the plunger 72' and interrupt the circuit to the driving motor 30. Inasmuch as the lower surface of the bracket leg 47 lies in a common plane with the lower surface 42 of the closure 40, it will be apparent that when the closure is swung away from closed position, leg 47 will overlie the upper end of the latch rod 50 and maintain the same in its depressed or retracted position against the action of spring 54.

Thus, in the over-all operation of the mechanism above described, it will be apparent that when the several parts of the drier are as shown, with cover 40 closed, the inner end of the lever 66 is held down by the action of spring 70. The end 64 of floating lever 61 is also held down; and the brake disc 62 is held from engagement with surface 25' of pulley 25, thereby permitting unimpeded rotation of the cage 14 by the action of the motor 30. At the same time, end 51 of latch rod 50 is projected upwardly into operative latching engagement with hole 52 in the lower leg or latch. element 47 of the closure 40 to thereby maintain the closure in locked covering relation over the cage 14.

Also, in this position of parts, the abutment 73 on the rod 50 is raised above the switch control plunger 72 so that the switch 71 may thus close the circuit to the motor 30 and maintain the circuit to the latter closed.

As previously stated, the motor 30 is of the reversible type, whereby in any drying operation, the cage 14 may be rotated first in one direction and then the other. In such case, the brake mechanism 6225 may be applied by suitably depressing the treadle 69 to bring the cage 14 to a stop, the hand switch to motor 30 being meanwhile moved to reverse position so that, upon release of the braking means, the cage will be rotated in an opposite direction.

When it is desired to bring the cage 14 to a stop for removal and recharging of its contents, suitable downward pressure on the treadle 69 will function to swing the floating lever 61 upwardly. The brake disc 62 will operatively engage the cooperating braking surface 25' of the pulley 25, with a pressure which will be proportional to the force exerted on treadle 69.

As soon as brake disc 62 engages pulley 25, the lever 61 will commence to fulcrum about its pivotal connection 63 with the brake disc to pull the latch rod 50 downwardly. The upper end 51 of the rod will move out of operative latching engagement with the latch element or portion 47 of the bracket 46. Further, the interaction of the abutment 73 on rod 50 and the plunger 72 of switch 71 will open the circuit to motor 30. Moreover, by the time latch rod 50 is fully retracted, the interaction between the braking elements 62 and 25 will have brought cage 14 to a complete stop.

When cover 40 is opened, the upper end of the rod 50 will be engaged by the over-lying lower surface of the latch element 47. Thus, rod 50 will be held down when the cover is open and abutment 73 on the rod Will hold micro-switch 71 open to maintain the circuit to motor 30 open.

It will be apparent that motor 30 may not start while cover 40 is open. The circuit to the motor may not be closed until cover 40 is moved to closed position and the end 51 of rod 50 registers with opening 52 in leg 47 thereby permitting rod 50 to move upwardly under the action of spring 54, assuming, of course, that no pressure is being exerted on treadle 69. On upward movement of the rod 50, the cover becomes locked and plunger 72 of micro-switch 71 rises, thereby closing the circuit to motor 30.

When treadle 69 is pressed while the drier is in operation the stopping of motor 30, unlocking of closure 40 and braking of cage 14 occurs almost simultaneously.

Applicant has provided a centrifugal drier which is completely safe to operate. There is no possibility of the drier being started when the closure is open or the open ing of the closure while the drier is running. This is accomplished by a control mechanism which is of utmost simplicity compared to control devices in centrifugal driers of prior -design. Because of its simple design, the drier can be manufactured and sold at low cost; and, since its parts are few, upkeep costs for the purchaser will be low.

Although a cover 40 has been shown which swings on a horizontal plane, it will be apparent that a cover which opens in a vertical direction could be provided, the cover having a suitable latch element operative with the upper end 51 of rod 50. Further, while this invention has been described in connection with one embodiment thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations or departures from the present disclosure which come within known or customary practice in the art to which this invention pertains, and as fall within the scope of the invention or the limits of the appended claims.

' Having thus described my invention what I claim is:

1. A centrifugal drier comprising a cage rotatable on a vertical axis and having an opening at its upper end, a closure for said opening, means supporting said closure for movement to a closed and an open position, a latch member fixed to said closure, a latch element in the form of a vertically extending axially movable rod having an upper end and a lower end, said upper end being engageable with said latch member when said closure is in closed position to lock the closure in such position and movable downwardly from engaged position to unlock the closure, electric means including a normally closed switch for rotating said cage, means connected to said latch element for opening said switch responsive to movement of the latch element to unlock said closure, a floating lever having one end pivotally connected to said lower end of said latch element and extending beneath said cage, a first brake element connected to the bottom of said cage and rotatable therewith, a second brake element medially pivotally connected to said lever and extending adjacent said first brake element, and means connected to the end of said lever opposite said one end for swinging said lever about its connection with said latch element to bring said brake elements into engagement and only after such engagement pivoting said lever about its pivotal connection with said second brake element to move said latch element downwardly to unlatch said closure and open said switch.

2. A centrifugal drier comprising a cage rotatable on a vertical axis and having an opening at its upper end, a closure for said opening, means supporting said closure for movement to a closed and an open position, a latch member fixed to said closure, a latch element in the form of a vertically extending axially movable rod having an upper end and a lower end, said upper end being engageable with said latch member when said closure is in closed position to lock the closure in such position and movable downwardly from engaged position to unlock the closure, electric means including a normally closed switch for rotating said cage, means connected to said latch element for opening said switch responsive to movement of the latch element to unlock said closure, a floating lever having one end pivotally connected to the lower end of said latch element and extending beneath said cage, a first brake element connected to the bottom of said cage and rotatable therewith, a second brake element medially pivotally connected to said lever and extending adjacent said first brake element, and a medially fulcrumed lever having one end pivotally connected to the end of said floating lever opposite said one end and a free end to which a pivoting force may be applied, said fulcrumed lever when pivoted first pivoting said floating lever about said pivotal connection with said latch element and moving said second brake element into engagement with said first brake element, and after such engagement pivoting said floating lever about the pivotal connection between the floating lever and said second brake element whereby said latch element is moved downwardly to unlatch said closure and open said switch.

References Cited in the file of this patent UNITED STATES PATENTS 1,882,968 Schenck Oct. 18, 1932 2,026,510 Moyer Dec. 31, 1935 2,091,536 Van Impe Aug. 31, 1937 2,235,988 Frohwitter Mar. 25, 1941 2,343,694 Mitchum Mar. 7, 1944 FOREIGN PATENTS 409,671 Great Britain May 1, 1934

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