US2617163A - Core dipping and centrifuging apparatus and method of dipping cores - Google Patents

Description

Nov. 11, 1952 E. C. JETER ETAL CORE DIPPING AND CENTRIF'UGING APPARATUS AND METHOD OF DIPPING CORES 5 Sheets-Sheet 1 Filed April 8, 1947 E. c. JETER e. e. MURIE e. PASOOES INVENTOR dCffi-fifl/n ATTORNEYS.

m? 10.52 mom IP53 g Nov. 11, 1952 E. CORE DIPPING AN C JETER ET AL D CENTRIFUGING APPARATUS AND METHOD OF DIPRING CORES Filed April 8, 1947 5 SQeets-Sneet 2 E. G. JETER G. G. MURIE s. PASGOE INVENT RS 6763 WIFZg ;;D M%W ATTORNEYS.

Patented Nov. 11, 1952 UNITED STATS TENT OFFICE CORE. DIPPING AND CENTRIFUGING APPA- RATUS AND METHOD OF DIPPING CORES.

Delaware Application April 8, 1947, Serial No. 740,196

Claims.

This application is concerned with an apparatus for treating foundry cores, and more particularly with a machine for automatically applying core wash and centrifugall-y removingthe excess wash.

The configuration of many types of castings is such that it is necessary to employ cores built up from a plurality of individual core pieces. The cylinder block of an internal-combustion engine is an example of such'a product. In the past, the usual practice has been to give the individual core pieces an application of core wash as by dipping, spraying or brushing. The chief purpose of the core has been to ensure a smooth core surface and hence a smooth casting. These washed core pieces are dried and then assembled using a layer of core paste at the joints.

Recently it has been found advantageous in assembling engine. block cores to reverse the usual procedure by pasting together the unwashed core pieces after which the assembly is dipped into a bath of core wash and the excess core wash removed centrifugally. This process has been found particularlyvaluableas an aid in eliminating fins from the water jacket. This process is more fully described in application Serial No. 633,708, filed December 8, 1945, in the names of Edgar C. Jeter and Roy Corpi and now matured into United States Letters Patent No; 2,442,568, issued June 1, 1948, assigned in toto to the assignees of this application.

It is an object of this invention to provide an apparatus for rapidly and economically dipping pasted and assembled cores into a core wash and centrifuging off the excess core wash with a minimum of labor.

It is a further object of this invention to provide an apparatus for handling and centrifuging the comparatively fragile cores by mechanical equipment with a minimum of breakage.

With these and other objects in view, the invention comprises the arrangements, constructions, and combinations of the various elements of the structure described in the specification, claimed in the claims and illustrated in the accompanying drawings, in which:

Figure l is a side elevation of a machine constructed according to applicants invention.

Figure 2 is a, plan view of a machine constructed according to applicants invention.

Figure 3 is a vertical section of the-Worm. drive gearbox taken normally to the axis of the worm.

Figure 4-isavertical'section of-the worm drive gearbox taken parallelto the axis-ofthe worm.

In Figures 1 and Z- the basic conveying system employed to transport -the assembled cores through the process is composed of a pair of chains I0, passing over and supported by sprockets H and 12." Each of sprockets H and I2 and chains It are, of course, duplicated as shown in Figure 2. Sprocket H is driven clockwise slowly by motor 13 through reduction gearbox it, drive chain l5 and sprocket HS which is mounted coaxially with-sprocket ll-. Secured to chains I0 at regular intervals are core carriers l! to which may be secured cores; 18: Figure 2 certain of the core carriers IThave been omittedfor the sake of clarity.

Sprockets l2 are driven through chains ll! by sprockets ll. Sprocket I9 is mounted coaxially with sprocket [2' and is driven thereby. Sprocket ISL-in turn, drives chain 20' and cam 2| for a purpose which will become apparent;- as the description proceeds Cam-2| is also driven by motor 22 through gearbox 23 and chain 24F Core wash is containedin core wash-tank 25 'whichis supported on one end of lever 26 through link 29. Lever 26 is supported at pivot 21 and carries counterweight 28 to balance the weight of the core wash and core wash tank 25. The rotation of cam 2| imparts a'vertical reciprocating motion to core wash tank 25. Through links 39v and 3|, core wash tank 25 is kept in a horizontal position during its vertical reciprocations; These reciprocations are synchronized with: the movements of cores l8 on chains l0 so that. each core 18 is dipped at the proper moment, and the core wash tank 25 then drops awayto clear the clipped core and admit the next succeeding core. Cam IN is driven from two distinct sources of power, i. e., by motor 22 through gearbox-23 and chainid, and by sprocket l9 and-chain 2'0; The addition of motor 22 has been found to give a smoother action to core'wash tank 25.- Motors Hand 22 and the intermediate gearing are so selected that they each tend to drive cam 2 l at-the same speed. To accommodate varying speeds of" motor" l3 and its associated gearing due to varying loads, motor 22 may be'a high slip induction motor.

Each of core carriers 11 is 'rotatably mounted and is provided with a worm wheel 32. This worm wheel 32 engages with worm 33 which is placed with its axis horizontal and parallel to chains [6. The purpose of worm wheel 32 and worm 33 is to rotate the core carriers I1 and cores I8, Worm 33 is driven through gearbox 34 as shown in Figure 1. This gearbox is shown in greater detail in Figures 3 and 4. Here worm 33 is shown supported in bushing 35. This screw 33 is driven through gear 36 mounted on its end. Gear 36 is driven by the gear 3'! which, in turn, is driven by gear 38. Shaft 39 supports gear 38 on one end and bevel gear 40 on the other end. Bevel gear 40 is driven by bevel gear 4! mounted on shaft 42 mounted normal to shaft 39. V-belt pulley 43 is solidly mounted on one end of shaft 42. Sprocket 44 is mounted on the other end of shaft 42 through overrunning clutch 45. V-belt pulley 43 is driven by motor 46 through V-belt 41 (Figures 1 and 2). Sprocket 44 is driven from gearbox l4 through chain 4 8.

The various driving members driving sprocket 44 and the train of gears driving worm 33 in gearbox 34 are so chosen that worm 33 rotates at a speed such that advancing worm wheel 32 can engage therewith without rotation. After worm wheel 32 has traveled a short distance in engagement with worm 33 without rotation of worm wheel 32, a switch 49 is tripped by a member 50 secured to chains l energizing motor 46. This motor is chosen so that it will rotate V-belt pulley 43 faster than chain 48 rotates sprocket 44. When motor 46 is not energized, it is driven through overrunning clutch 45 at a speed well below its normal operating speed. Upon energization of motor 46, V-belt pulley 43 and all driving members driving worm 33 will accelerate and become disengaged from sprocket 44 by virtue of the action of overrunning clutch 45. This acceleration will, of course, increase the speed of worm 33 and cause rotation of worm wheel 32, core carrier l1 and core [8.

The length of worm 33 is approximately twice the spacing of core carriers I! on chains It. When the particular core carrier I! under consideration has traveled a distance along the worm somewhat less than the spacing of core carriers 17, motor 46 is (tie-energized and worm 33 decelerates in time to engage the following core carrier without causing this core carrier to rotate. Motor 46 is then again energized and causes both core carriers to spin. Thus any given core carrier I! will engage worm 33 and travel a short distance without rotation, then accelerate angularly and travel a distance somewhat less than half the length of worm 33 while spinning then decelerate to rest in so far as angular motion is concerned, then reaccelerate angularly and spin until the end of the worm is almost reached and then decelerate angularly and cease spinning just prior to the disengagement of worm 33 and worm wheel 32.

With the above explanation, it is thought that the construction and operation of applicants device can be clearly understood. Turning to Figure 1, theassembled cores are loaded at the Loading station and securely clamped to core carriers IT. The cores are carried to the right on the upper reach of the conveyor, around sprocket l2 and approach core wash tank 25. As each core aproaches core wash tank 25, the tank is lowered by cam 2! to clear the core, then raised to immerse the core in core wash and then again lowered to clear the core. As soon as the core is clear of core wash tank 25, the worm wheel 32 associated with the core which has just been dipped, engages with worm 33. However, worm 33 is synchronized with the movement of the core so that for a portion of the travel of the worm wheel 32 along worm 33, no rotation of worm wheel 32 or the core takes place. However, as explained above, when motor 46 is energized, the speed of worm 33 is increased and the worm wheel 32 and associated core is rotated. By this means it is possible to impart to the core the smooth gentle angular acceleration which is required to prevent breakage. Of course, such rotation ceases before worm wheel 32 clears the left end of worm 33. At this time motor 46 is de-energized and worm 33 slows down to the speed set by motor l3.

We claim as our invention:

1. The process of removing excess core wash from a core comprising subjecting the washed core to substantial centrifugal force by rotating the core at least twice with a period of rest interfnosed between the applications of centrifugal orce.

2. The process described in claim 1 in which the cores are continuously moved on a conveyor and in which the application of centrifugal force to the cores is continued through a length of travel which is substantially longer than the distance between successive core carriers.

3. The method of treating foundry cores comprising continuously conveying the cores in a fixed path, which path includes at least one vat containing a liquid adapted to treat the cores, elevating said vat whenever a core is positioned thereover, lowering the vat to clear the core as it progresses along said fixed path spinning the dipped core, arresting the spinning of the core and again spinning the core.

4:. In a core treating apparatus a conveyor adapted to continuously convey cores in a fixed path, a series of spaced and rotatably mounted core carriers forming a part of said conveying system, a worm wheel arranged to rotate each of said core carriers and hence to rotate a core supported on said core carriers, and a Worm adapted to rotate said worm wheel and core carriers, said worm being arranged with its axis parallel to the movement of the adjacent cores and being provided with driving means arranged to rotate the worm at a speed such that the Worm wheel can be engaged with and moved along the Worm without rotation immediately after engagement and later at a speed appreciably differing from the first-mentioned speed, so that rotation is imparted to the worm wheel and in which one of the speeds of the worm is obtained by a drive actuated by the conveyor system, and the other from a separate source of motion and in which the lower of the two speeds is obtained from a drive which includes an overrunning clutch.

5. In a core treating apparatus a conveyor adapted to continuously convey cores in a fixed path, a series of spaced and rotatably mounted core carriers forming a part of said conveying system, a worm wheel arranged to rotate each of said core carriers and hence to rotate a core supported on said core carriers, and a worm adapted to rotate said worm wheel and core carriers, said worm being arranged with its axis parallel to the movement of the adjacent cores and being provided with driving means arranged to rotate the worm at a speed such that the worm wheel can be engaged with and moved along the worm without rotation immediately after engagement and later at a speed appreciably differing from the first-mentioned speed, so that rotation is imparted to the worm wheel and in which the lower speed of the worm is obtained by a drive from the conveyor system which includes an overrunning clutch and the higher speed is obtained from a separate motor.

EDGAR C. JETER. GILBERT GREER MURIE. GEORGE PASCOE.

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

UNITED STATES PATENTS Number Name Date Fielding Mar. 3, 1903 Merritts Mar. 14, 1905 Bernardin July 13, 1909 Schnell May 25, 1926 Mueller Apr. 9, 1929 Vaughan Oct. 23, 1934 Newton Dec. 10, 1935 Vance Aug. 17, 1937 Schweitzer Feb. 10, 1948 Jeter et al. June 1, 1948

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