US1819803A - Crane - Google Patents

Description

Aug. 1931.

w. WHITE (IRANE Filed Dec. 26, 1929 2 Sheets-Sheet l INVENTOR ATTORNEYS Aug. 18; 1931. w. WHITE 1,819,803

CRANE Filed Dec. 26, 1929 2 Sheets-Sheet 2 e2 INVENTOR MAL/4M M7775 BY I v v I Z0 .l

ATTORNEYS V Patented Aug. 18, 1931 UNITED STATES PATENT ()FFICE Y :1; WILLIAM WHITE, O13 CLEVELAND, OHIO, ASSIGNOR TO THE EUCLID CRANE 8t HOIST COMPANY, OF EUCLID, OHIO, A CORPORATION OF 01-110 CRANE Application filed December 26, 1929. Serial No. 416,507.

a a tilting dumping platform allowing sufiicient can tilt that the freed ice block may slide from the can. Of course in practice it is customary that a number of cans may be so handled simultaneously in parallel relation.

Unfortunately, the friction between the ice and can surfaces, due to refreezing, lack of smoothness, and the like, gives rise to a tendency of the ice cakes to stick instead of sliding from the cans; Whereas we have found that such difficulties are not encountered if the cans have sufficient angular speed from vertical to dumping. positions.

Broadly, therefore, it is the object of this invention to eliminate such difficulties; and

to this end to provide for more rapid-crane operation'in this critical part 'of the cycle, wherein the can is being rotatably lowered to N dumping osition, than is had in other parts thereof.

ore particularly I provide for high speed operation of the crane when lowering the can in'the dumping position.

It is often convenient or necessary that al- I ternating current be employed as the source of power. According to my invention 1 provide for the hoist such a motor wound for two speeds and preferably of squirrel-cage type, provide operator-controlled connections for the motor that the operator may start,

' stop and reverse the same, and arrange additional and independent motor connections making possible high speed operation of the motor when the can'is being lowered on the 3 dump, and insuring low speed operation only 45 of this motor otherwise. I

The exact nature of this invention together with further objects and advantages thereof will be apparent from the followingdescription, taken in connection with the accomp anying drawingsin which Fig. 1 is a side elevation of an assembly of crane parts pertinent to my invention showing particularly a bridge end-truck and indicating an ice can carried by the trolley thereof, and by broken lines indicating also other positions to which the canmay be caused to move as by travelling operation of the trolley hoist; Fig. 2 is an elevation of the same, transverse of the Ways upon which the bridge moves, and indicating three ice cans to be handled simult'aneously; Fig 3 is a conventionalized showin g of the hoist motor with its principal associated controlling parts; and Fig. 4 is'a simplified circuit diagram of the same.

With reference now to the drawings the principal parts arranged to support the crane are a pair of ways 1, one being shown, it being understood that the ways are stationary and arranged in spaced parallel relation as upon opposite walls of a rectangular freezing room. Extending between the ways 1 is a bridge carried by end trucks movable on the Ways.' The principal structural parts of the bridge are the beams 52, and of the end trucks are the frames 3 and wheels 4. A

motor indicated at 5 is geared as at 5a to one set of the wheels 4 to control the bridge travel.

Movable on tracks 6 carried above the beams 2 of the bridge, is a trolley having a frame 7 and supporting Wheels 8 for the purpose of moving the trolley,a motor 9 being geared as at 9a to a pair of the wheels 8 to control traversing movement. Mounted on the frame 7 for traversing movement therewith upon the bridge is a hoist unit comprising a hoist motor 10 ar ranged to drive a shaft 11 through a gear box 12. V

Secured on the shaft 11 are a number of hoisting drums 13, three being shown. A pulley block 14 is provided for each drum 13 and connected therewith by a cable rigging which includes a stretch 15 dead-ended as at 16 on the frame 7, and a stretch 17 leading from the pulley block 14 to the drum 13, the cable having of course a live end connection with the drum.- Each pulley block 14 is provided with a hook 18 by which an ice" can operate only at its lower speed.

19 or a grid supporting a number of cans may be engaged.

Obviously what has thus far been described is more or less typical of overhead crane or travelling hoist practice; and it will be apparent that the three cans 19 appearing in Fig. 2, or any plurality of cans associated as by a grid, will be manipulated by the crane in parallel relation in all respects. Therefore hereinafter but one hoisting unitthat is, but one unit from a can 19 to the shaft 11will be considered.

Preferably according to this invention the hoist motor 10 which is to operate on alternating current is of constant speed characteristic such as the squirrel-cage type with high and low speed windings indicated at 10a and 10?) respectively, Fig. 4. This motor, as are the others described, has associated therewith the usual control means such as operator-operated controller 50, Fig. 3, actuated by pull ropes or the like. This controller 50 may have the usual contactor drum indicated Fig. 4;.

However, I provide for the hoist motor an additional control, independent of operator control; whereby lowering operation of the hoist motor, when the trolley is at dumping position, may be at the higher of its two speeds, whereas otherwise this motor will To this end I associate with the hoist motor 10, a switch 20 preferably located on the trolley as shown, and adapted to control whether or not the higher operating speed of the hoist motor is available to the operator. Details of the switch mechanism are indicated Figs. 3 and l. The switch is controlled by a lever 21 yieldably urged from closed position to vertical open position as indicated in broken lines at 21a, Fig. 1, by a spring 22'having connection with the arm 23. The lever 21 carries a roller 24: cooperable with a projection 25 conveniently fixed as to theceiling 26, or wall, of the freezing room. In Figs. 3 and 4 the switch 20* is shown in open position, closed position being indicated by broken lines, Fig. 3.

The location of the projection 25 and the relation of the parts are such that the lever 21 will be depressed by the projection 25 as indicated in full lines Fig. 1, to make possible high speed lowering operation of the motor 10, when the can 19 is in dumping position over the dump platform or tilting table 27; whereas under all other conditions the motor 10 will operate at low speed only. The platform 27 is arranged to tilt from upright position shown, to dumping position indicated in dot-dash lines 27a.

Operation will be as follows: Assuming the can 19 in the freezing brine and containing a solid cake of ice just frozen, the crane is operated in the usual manner to engage the can by the hook 18 and the can is raised by the crane hoist, out of the brine. The bridge is then moved along the ways until the can is over the hot dipping tank, the trolley being traversed on the bridge if necessary to this end. The can is next lowered into the dipping tank until the heating medium therein melts the ice cake sufficiently to free its faces from the sides of the can. The can is then lifted from the dipping tank; the bridge (including the trolley if necessary) is then moved until the can is over the tilting table 27. The can is lowered onto the tilting table, positions 19 to 19a Fig. 1 and the hoist motor continuing its lowering operation to pay out cable from the drum 13, the can and tilting table move about the axis of the latter until the can is in position 19?), when the ice cake slides therefrom under the action of gravity. The automatically operated switch 20 being closed when the crane is in position over the dump or tilting table, it is possible to lower the cans from position 19a to position 196 at high speed.

The empty can is then returned to position 19, refilled with water, traversed to 1ts position over the freezing tank and lowered at low speed intothe freezing brine therein.

More particularly with reference to Fig. 4:

the contactor drum is provided with three rows of contactors 50a, 50b, and 500, with which cooperate in the usual manner the row of contact fingers 51. The contactors 50a and 506 are lowering contactors and 500 are hoisting contactors.

52 are trolley brushes by which feed connection from the line wires L1, L2, is maintained regardless of the maneuvered positions of the hoist parts. 53 is the usual two pole main line limit switch, and 54 is the shunt brake solenoid coil. I

Suppose now the controlleddi'um is shifted to hoisting position, so that contactor rows 50c and 51 are superimposed. It will be apparent that the three terminals of the low speed motor windings 10?) have supply connections with the three line wires L1, L2, L3, by way of the parts shown sothat the hoist raises at low speed. The high speed windings 10a are not energized.

Suppose the controller drum now shifted to the first or low speed lowering'position, so that the contactor row 51 is superimposed upon row 50?). Again the low speed windings 10?) are energized and the windings 10a not energized, but now two phases of the windings 10?) are reversed, so that the hoist lowers, at'low speed, and should the switch 20 now close, the low speed operation would continue.

Should the controller next be shifted to register the contactor rows 50a and 51, the low speed windings 10?) would be deenergized, but energization of the high speed windings 10a would be dependent upon closingof the switch 20. This switch, when closed, allows manipulation of the controller drum in lowering direction, as a two-speed controller.

It will be noted that while the arrangement described is quite simple, it nevertheless insures speedy handling of the can after the cake is freed therein and until the ice cake is cleared therefrom; and what is also important, insures that the can is lowered slowly into the freezing brine so that the can contents are not contaminated by slopping over of the brine.

What I claim is:

In a crane for moving ice cans between freezing, dipping, and dumping positions, and having for the purpose a hoist and a trolley carrying the same, a motor for said hoist, automatic control means to provide high speed lowering operation of said motor when said trolley is in dumping position and operation of said motor at a lower speed under other conditions, said control means comprising cooperative control parts, one fixed and the other arranged to be movable with said trolley and associated switch means arranged in the circuit of the motor, and operator-operated control means for said motor providing for hoisting and lowering operation of said hoist under the conditions imposed by said automatic control means.

In testimony whereof I hereby aflix my signature. 7

WILLIAM WHITE.

Images