US2463874A - Safety system for centrifugal dischargers - Google Patents

Description

March 8, 1949. J. HERTRICH ETAL 2,463,874

' SAFETY SYSTEM FOR CENTRIFUGAL DIS CHARGERS Filed April 17, 1947 2 Sheds-Sheet l INVENTORS JOSEPH HERTR/CH R 1A RD H055 ATTORNEYS March 8, 1949.

J. HERTRICH ETAL 2,453,374

7 SAFETY SYSTEM FOR CENTRIFUG'AL DISCHARGE-RS Filed April 17, l947 2 Sheets-Sheet 2 55 .3 I V l I 1 ia. 31 \4 v INVENTORS V JOSEPH HERTR/CH n filyflRD HUSE' v ATTORNEYS Patented Mar. 8, 1949 SAFETY SYSTEM FOR CENTRIFUGAL DISCHARGERS Joseph Hertrich, Hamilton, and Richard Huser, Mount Healthy, Ohio, assignors to The Western States Machine Company, Hamilton, Ohio, a

corporation of Utah Application April 17, 1947, Serial No. 742,188

Claims.

This invention relates to a safety system for centrifugal dischargers of the kind used in sugar manufacture.

The dischargers used for sugar centrifugals generally comprise an arcuate plow or shoe of sturdy construction carried on the lower end of a heavy vertical shaft supported for axial movement into and out of the centrifugal basket. To perform a discharging operation, an operating mechanism connected with the shaft, including a handwheel, is turned to lower the shoe into the basket, and the basket is rotated slowly while the shoe is turned into its revolving contents. The basket contents thus dug out pass through an opening in the basket bottom, which normally is closed by an annular valve but is exposed just before each discharging operation by lifting and supporting the valve in an out-of-the-way position. Upon completion of the operation the discharger shaft and shoe are raised out of the basket and turned to rest upon the curb top, and the bottom valve is replaced to prepare the basket for another centrifugal operation at high speed. The curb top usually has a detent for retaining the discharger shoe in its inoperative position until the time for another discharging operation. Despite all known precautions, however, there is danger of the shoe becoming free and falling into the basket while the basket is running at high speed, which may result from excessive vibrations or from careless or inadvertent action of the centrifugal attendant. If this occurs, destruction of the apparatus and serious or fatal personal injuries are likely to result.

The object of this invention is to obviate hazards in the use of centrifugal dischargers through the provision of an improved safety system whereby the discharger is locked safely in itemoperative position when not in operation and yet is freed readily for operation inside the basket during periods of the successive centrifugal cycles when it is needed. A further object of this invention is to provide a safety system of this type whereby the discharger operating mechanism is locked automatically to prevent vertical movement of the discharger shaft and shoe into the basket whenever the centrifugal basket is not ready for a discharging operation, and whereby the operating mechanism is freed automatically to permit discharging in the usual manner, through the act of lifting and supporting the bottom valve of the basket in preparation for a discharging operation.

These and other objects are achieved according to this invention by the provision of an improved shiftable locking device in association with the usual discharger mounting on the top of the centrifugal curb, which device is arranged to engage and prevent operation of the mechanism by which the discharger shaft and shoe are moved vertically into and out of the basket. The device is normally held in this locking position by suitable biasing means, such as a spring, but it is shiftable from that position, to an ineffective position where the mechanism is free for normal operation, by the action of retracting means overcoming the force of the biasing means. According to a preferred embodiment, the retracting means comprises a hanger which receives and holds the bottom valve of the basket when the valve is displaced to expose the bottom opening of the basket for a discharging operation, and the retracting means responds to the weight of the valve held on this hanger so as to overbalance the force of the biasing means and retract the locking device to its ineffective position. Through the correlated action of the biasing means and this retracting means, the discharger mechanism is re-locked automatically upon the removal of the bottom valve from its supporting hanger to make the basket ready for another centrifuging period, at which time, according to usual practice, the discharging operation has been completed and the discharger shaft and shoe have been moved out of the basket to their inoperative position on the top of the centrifugal curb.

An exemplary embodiment of the invention is described in detail hereinafter and is illustrated in the accompanying drawings, forming a part hereof, wherein Fig. 1 is a vertical section through the basket and curb of a suspended gyratory centrifugal machine equipped with said embodiment;

Fig. 2 is an enlarged plan view of parts of the assembly of Fig. 1;

Fig. 3 is a vertical section approximately along line 33 of Fig. 2, showing the locking device partly in elevation and partly in section;

Fig. 4 is an end elevation of the locking device as viewed from adjacent the spindle of the centrifugal; and

Fig. 5 is an end elevation looking toward the handwheel.

As seen in Fig. 1, according to usual practice for sugar centrifugals, a suspended gyratory spindle I0 carries a perforate centrifugal basket l2 inside a surrounding curb or stationary casing 26 which receives liquid expelled from the contents of the basket through its side wall perforations during the centrifuging or running periods of the machine. The basket l2 has a bottom l3 formed with an annular opening M interrupted only by radial spokes to the shaft Ill, which opening normally is closed by an annular valve I 5 having one or more handles I 5 by which the valve may be lifted and held away from the bottom opening. The basket top ii is annular, forming a circular opening [5 surrounding spindle Hi. The curb has a top 2| formed with an opening 22 likewise surrounding spindle H). A sector-shaped part 23 of the curb top extends inwardly to a location near spindle NJ as seen in Fig. 2.

The discharger shown is'the well known form of U. S. Patent No. 2,076,516 to Eugene Roberts. It comprises a vertical shaft 33 having shoe 34 on its lower end and a supporting housing mounted through base plate 3i on curb top 25. A bearing or guide 32 of the housing forms a vertical passage through which shaft 33 extends for axial movement. A handle 35 on the upper end of shaft 33 permits turning it so that the shoe 34 can be moved toward and away from the side wall of basket [2, when the shoe and shaft are inside the basket, or to and from an idle position over the curb top 2! when the shoe and shaft are raised out of the basket.

Along one side shaft 33 has a gear rack (not shown) meshing with a pinion 45. The pinion is secured to the inner end of a pinion shaft 4| heldrotatably in bearings 42 and 43 of housing 39. To the outer end of shaft 4i is fixed a handwheel 44 having radial spokes a5, and having an operating handle 46. It is evident that rotation of handwheel 44 acts through shaft 4! and pinion to move the discharger shaft axially in the shaft bearing 32, so that the shaft and shoe 34 on its lower end may be raised and lowered with respect to the basket l2. When the shoe is inside the basket handle 35 may be turned to dig the shoe into the discharge the basket contents. When the shoe is fully raised outside the basket and above the curb top, it may be turned to rest in an operative position on the curb top. But movement of the shoe from its fully raised, or inoperative, position to an operative position inside the basket cannot occur Without axial movement of shaft 33 and accompanying rotation of the operating machanism comprising pinion 40, pinion shaft 4i and handwheel 44.

This movement is normally prevented by the action of the safety device indicated generally at in Fig. 3. A bracket 5i is mounted on curb top 2| near housing 3% by attachment to a part of base plate 3!. A slideable locking pin 52 extends through bearings 53 and 54 of bracket 5|, in such location that the outer end 55 of the locking pin normally extends into the handwheel 44 between two of its spokes 45. Thus pin 52 normally engages and prevents operation of the handwheel, and this normal or locking position is maintained by the force of biasing means shown here in the form of a compression spring 56. One end of spring 56 bears against the face ofbearing 54 and its other end bears against a collar 51 secured to pin 52.

The locking pin 52 is movable, however, away from its normal or looking position, against the force of the spring 56, by the action of suitable retracting means, such as a bell crank lever 66 connected with the inner end 58 of pin 52. The hub 6| of lever 60 is held rotatably on a pin 52 secured in a part 63 of bracket 5|, thus providing a fixed fulcrum. Arm 64 of th lever has a swivel connection through hub 65, pin 66 and Ill coupling 61 with the inner end 58 of slidable locking pin 52. The other or inner arm 68 of lever 60 extends to a location near the centrifugal spindl ll! (Figs 2 and. 3), where it is connected through pin H with a swivel block or coupling carrying a depending'hanger in the form of a hook.

Hanger l0 depends from coupling 69 through an opening '52 in a bracket 73, which holds the hanger in proper position and limits its downward movement by abutment with coupling 69. The hooked end of hanger 10 below bracket 13 is thus arranged and formed to receive and hold the basket bottom valve l5, which it does by retaining one of the handles it as seen in Fig. 3, when this valve is lifted away from the bottom opening Hi to prepare the basket I2 for a discharging operation.

The arrangement of lever 50, with hanger 10, locking pin 52 and spring 56 is such that the Weight of the bottom valve l5 held on hanger 10 cverbalances the force of spring 55, thus moving hanger m and lever arm 68 downward and turning lever arm 5Q so as to slide pin 52 inwardly against the spring and free its outer end 55 from engagement with the handwheel 44. Consequently, the discharger operating mechanism and the discharger itself are free for operation whenever the basket bottom valve is held'on its supporting hook, but are locked against operation at all other times in the working of the machine.

In the use of the apparatus, the centrifugal basket 52 is loaded with its bottom valve l5 in place as seen in Fi l, the discharger then being all of this running period the locking pin 52 has been held in its normal position by spring 56, with its outer end 55 extending into and preventing operation of the handwheel 44, so that the discharger has been held and locked securely against accidental or inadvertent displacement into the running machine. When the basket has stopped or reached a suitable low speed the attendant reaches in, grasping a handle l6 of bottom valve l5, and lifts the valve to place it out of the way on hanger W, as seen in broken lines in Fig. 3. weight of the valve so as to overbalance the force of spring 55 and retract the effective end 55 of locking pin 52 from the handwheel 44,

Accordingly, the very act of placing the basket in readiness for a discharging'operation serves automatically to free the discharger mechanism' for operation. The centrifugal attendant'then proceeds to manipulate the discharger in the usual way, and at the end of the discharging opbasket and above the curve top 2f.

10 to replace the valve over the'bottom opening It in readiness for another loading operation, and this customary step results automatically in movement of the locking pin underthe force of spring 56 so as to reengage and prevent oper ation of the discharger mechanism during the loading and the running periods of the succeeding cycle of the machine.

It will be evident to thoseskilled in the art" that the new-features of construction 'and'oper ation herein disclosed and claimed'as "our inven-"" Lever til thereupon responds to the tion may be embodied in various forms of apparatus without restriction to the details of the form which we have shown and described herein by way of exemplification.

We claim:

1. In combination with a centrifugal discharger comprising a housing adapted to be mounted on the top of a centrifugal curb, a vertical discharger shaft supported by said housing for axial movement and carrying a discharger shoe on its lower end, and mechanism supported by said housing and connected with said shaft for moving it axially to carry said shoe into and out of a centrifugal basket within said curb, a shiftable locking device mounted adjacent said mechanism having a part interlocked with a motive part of said mechanism to prevent operation of said mecha nism in one position and moved free of part to enable operation of said mechanism when shifted to another position, biasing means acting upon said locking device to hold the same normally in said one position, and retracting means connected with said device and movable to shift it to said other position against the force of said biasing means, said retracting means comprising an element adapted to receive and hold the bot tom valve of the centrifugal basket during periods for operation of the discharger and being moved in response to the weight of such valve held on said element to overbalance said biasing means and shift said device, so that the discharger shaft and $1109 may be locked safely in raised position out of the basket and may be moved into the basket only when the basket valve has been lifted and placed on said element in readiness for a discharging operation.

2. In combination with a centrifugal discharger comprising a housing adapted to be mounted on the top of a centrifugal curb and having a vertical shaft guide, a discharger shaft extending through said guide and carrying a discharger shoe at its lower end, said shaft movable axially in said guide to locate said shoe inside a centrifugal basket within said curb to discharge contents of said basket and to locate said shoe in a raised position outside said basket and curb, and manually operable mechanism for so moving said shaft including a rack thereon, a pinion meshing with said rack, a pinion shaft held rotatably by said housing and a handwheel on said pinion shaft, a locking pin slidably/mounted adjacent said housing and having one end adapted to extend between the spokes of and prevent rotation of said handwheel in one position of said pin, said pin slidable to another position to free said handwheel, a spring normally holding said pin at said one position, and a pin retracting lever having an arm articulated to said pin, a fixed fulcrum and another arm movable downward to overbalance the force of said spring and slide said pin to said other position.

3. In combination with a centrifugal discharger comprising a housing adapted to be mounted on the top of a centrifugal curb and having a vertical shaft guide, a discharger shaft extending through said guide and carrying a discharger shoe at its lower end, said shaft movable axially in said guide to locate said shoe inside a centrifugal basket within said curb to discharge contents of said basket and to locate said shoe in a raised position outside said basket and curb, and manually operable mechanism for so moving said shaft including a rack thereon, a pinion meshing with said rack, a pinion shaft held rotatably by said housing and a handwheel on said pinion shaft, a locking pin slidably mounted adjacent said housing and having one end adapted to extend between the spokes of and prevent rotation of said handwheel in one position of said pin, said pin slidable to another position to free said handwheel, a spring normally holding said pin at said one position, a pin retracting lever having an arm articulated to said pin, a fixed fulcrum and another arm to extend over the top opening of the basket to a point adjacent its spindle, and a hanger articulated to and depending from said other arm to receive and hold the bottom valve of the basket during periods for operation of the discharger, said lever being responsive to the weight of such valve held on said hanger to overbalance the force of said spring and slide said pin to said other position.

4. A safety device for a centrifugal discharger comprising a bracket adapted to be mounted on the top of a centrifugal curb adjacent to the discharger housing, a locking pin slidably held in said bracket and having one end adapted to engage and prevent operation of the discharger operating mechanism in one position of said pin, a spring carried by said bracket and normally biasing said pin to said one position, and a lever fulcrumed upon said bracket having one arm articulated to the other end of said pin and having an operating arm movable downward to over balance the force of said spring and slide said pin to another position to free said mechanism for operation of the discharger.

5. A safety device for a centrifugal discharger comprising a bracket adapted to be mounted on the top of a centrifugal curb adjacent to the discharger housing, a locking pin slidably held in said bracket and having one end adapted to engage and prevent operation of the discharger operating mechanism in one position of said pin, a spring carried by said bracket and normally biasing said pin to said one position, a bell crank lever fulcrumed upon said bracket having one arm articulated to the other end of said pin and having an operating arm to extend over the top opening of a centrifugal basket within said curb, and a hanger articulated to and depending from said other arm to receive and hold the bottom valve of said basket during periods for operation of the discharger, said lever being responsive to the weight of such valve held on said hanger to overbalance the force of said spring and slide said pin to another position to free said mechanism for operation of the discharger.

JOSEPH HERTRICI-I. RICHARD HUSER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,205,128 Mackintosh Nov. 14, 1916 1,388,173 Daniels Aug. 23, 1921 2,063,472 Tholl Dec. 8, 1936 2,076,516 Roberts Apr. 6, 1937 2,377,070 Campos May 29, 1945 FOREIGN PATENTS Number Country Date 204,937 Great Britain r Oct. 11, 1923 Certificate of Correction Patent No. 2,463,874. March 8, 1949.

JOSEPH HERTRICH ET AL. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 41, for the word the before discharge read and;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 16th day of August, A. D. 1949.

THOMAS F. MURPHY,

Assistant Uommz'ssz'oner of Patents.

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