US3522837A - Centrifugal pipe casting - Google Patents

Description

United States Patent [72] Inventor: Louis Philippe Giguere Terrasse Duvernay, Trois Rivieres,

Quebec, Canada [21] Application No.: 632,371 [22] Filed: April 20, 1967 [4S Patented: Aug. 4, 1970 [73] Assignee: Canada Iron Foundries, Limited Montreal, Quebec, Canada [54] CENTRIFUGAL PIPE CASTING 6 Claims, 6 Drawing Figs.

[52] U.S. Cl. 164/299 [51] Int. Cl. 322d 13/10 [50] Field ol'Search 164/295,

Arnold et al 164/301 3,334,683 8/1967 Walker 164/301 1,736,424 11/1929 Bell 164/118 1,944,168 1/1934 Camerota.. 164/298 2,763,041 9/1956 Doat 164/155 2,932,874 4/1960 Ludwig et al. 164/298X 3,171,171 3/1965 Farr et al. l64/298X FOREIGN PATENTS 679,075 9/1952 Great Britain 164/300 598,828 2/1948 Great Britain 164/272 Primary Examiner- 1. Spencer Overholser Assistant Examiner- V. K. Rising Allorney Alan Swabey ABSTRACT: A centrifugal iron pipe casting apparatus with twin ladles each with a pouring trough arranged for movement of one ladle and trough into pouring position while the other is moved out of pouring position for filling and cleaning. The ladles are mounted on a carriage provided with downwardly facing supporting rails running on fixed rollers to avoid any deposit on the rails which would interfere with smooth travel. A fluid pressure actuating device moves the carriage back and forth and terminal cushioning means ensures smooth acceleration and deceleration.

Pa tented Aug. 4, 1970 m L A ATTORNEY Patented Aug. 4, 1970 Sheet ms Q Q R 6% INVENTOR Louis Philippe GIGUERE v bPm A TTORNEY Patented Aug. 4, 1970 Sheet INVENTOR Louis Philip pe GIGUERE Q m u h ATTORNEY US. PATENT 3,522,837 C ENTRIFUGAL PIPE CASTING This invention relates to an apparatus and method for easting iron pipe.

The conventional method of casting iron pipe involves a cycle in which a mold carriage is moved back and forth between a position in which the pouring of the metal is started to a position where the pouring is finished. A trough extends within the mold leading from the ladle. As iron is poured from the ladle and flows from the trough into the mold, the mold carriage moves away from the ladle. The rotation of the mold and the movement of the carriage are synchronized in conjunction with the pouring of the iron. Once the pipe is completed, the ladle must be filled again and the trough cleaned before the carriage can be moved back to pour another pipe. This takes time and delays the return of the carriage so that the mold is not used to maximum capacity.

lt is an aim of the present invention to remedy these shortcomings with the conventional apparatus and to provide cer tain positive advantages as will be clear from the following description.

The invention provides an apparatus for casting iron pipe in which there is a carriage mounting a plurality of ladies and a trough operatively related to each ladle. The carriage is adapted for movement between positions in which each ofthe respective ladies are in pouring position. Means is provided for moving the carriage between these positions and control means is provided for controlling the movement in such a manner.

The invention has been generally described and it will now be referred to in more detail by reference to the accompanying drawings, which illustrate preferred embodiments, and in which:

FIGURE 1 is a plan view showing a general arrangement of a casting machine according to the invention with the mold carriage in down position and the ladle carriage positioned so that one ofthe ladles is ready to pour and its trough ready to receive the mold.

FIGURE 2 is a similar view to FIGURE 1, but with the ladle carriage moved so that the other ladle and trough are in pouring position.

FIGURE 3 is a side elevation, partly in section, showing the apparatus of FIGURES l and 2 with the mold carriage in down position, dotted lines showing its up position.

FIGURE 4 is a rear elevation of the apparatus on a greatly enlarged scale, showing particularly the arrangement of the ladies and operating mechanism on the ladle carriage.

FIGURE 5 is a side elevation, generally on the plane ofline 5-5 of FIGURE 4, on the scale of FIGURE 4, showing the ladle carriage and ladies.

FIGURE 6 is a horizontal cross-section, partly in elevation, on a still further enlarged scale, showing the ladle carriage-operating cylinder and hydraulic connections.

Referring especially to FIGURES l to 3 a general arrangement of the casting machine is shown. An inclined bed extends fr'om adjacent to the upper or pouring end to the lower or pipe discharge end (from left to right in FIGURES l to 3 and a mold carriage A is adapted to run on rails along this bed during the process of casting. A motor is shown for rotating the mold as the carriage A advances from the upper end ofthe bed 15 toward the lower end, during pouring of the iron. A

bell core 23 is supplied to the mold to form the end of the cast,

pipe, as well understood, during the casting operation. The nature of the mold and other features so far described are standard. 44 are skids which swing out ofthe way for movement of the carriage A along the bed 15 but which are brought into the position vacated by the carriage to receive the cast pipe and carry it off to one side.

In accordance with the invention, a carriage B is provided which travels transversely of the mold at the upper end of the .bed 15. The carriage is moved by a hydraulic cylinder (not shown) within the bed 15. This carriage includes twin pouring troughs C and Cl and twin ladles D and D1, details of which will later be described.

The carriage B is supported by a pair of parallel spaced apart horizontally extending rails 31 and 33 having downwardly extending running surfaces which run on pairs of spaced apart smooth surfaced rollers 35 and flanged rollers 36 which are suitably journalled in brackets 39 and 4lll respectively in a line perpendicular to the direction of travel of the carriage A. 42 represents a water cooling device.

The ladle D has axles 51 and 51a carried in respective journals 53 mounted on a superstructure 55 on the carriage B. An electric motor 57 has a drive connection with a speed reducer 59 which in turn has a driving connection through a crank arm 65 pivotally connected to a rod 67which is in turn pivotally connected to a pin 69 on the side of the ladle D. The arrangement of the ladle D1 and its parts are similar and the same parts as those of ladle D have been identified by the same numerals qualified with The carriage B is arranged to be moved back and forth between a pouring position for the ladle D to a pouring position for the ladle D1. The mechanism by which this is accomplished is as follows.

The cylinder 70 is fixedly mounted on the underside of the frame of the carriage B by brackets 71. A piston 73 operates within the cylinder 70 and is connected to a piston rod 75 which is anchored at one end to a stationary block suitably anchored to the floor. The cylinder 70 is provided at its respective ends with extension chambers 76, 77 of reduced diameter. The piston 73 is provided at one side with an extension 78 and at the other with an extension 79, these extensions being adapted to enter respectively the extension chambers 76, 77 in a sliding fit as the piston nears the ends ofits stroke.

A pipe carrying water pressure, say at 160 pounds per square inch, extends from a source of water supply to a valve 84. A pipe 82 extends from the valve 84 to a drain. Pipes 86 and 87 respectively extend from the valve 84 to a valve 85. Pipes 88 and 89 respectively connect the valve to inlet-outlets 91 and 93 respectively spaced from the respective ends of the cylinder 70. The valves 84 and 85 can be manipulated to cause fluid to enter the cylinder through the lines 88 or 89, thus causing the piston 73 to move in one direction or the other. A by-pass passage 95 extends from the extension chamber 76 to the line 88 and a by-pass passage 96 extends between the end of the extension chamber 77 to the pipe 89.

In operation, when the piston 73 nears the end of its travel, say, going in the right-hand direction, it will close off the outlet 93 and the extension 78 will enter the extension chamber 76 and will be cushioned by the fluid in the extension chamber 76 and will thus slow down gradually. This is important to the operation of the apparatus since it is necessary to prevent any jerking movement or abrupt stop of the carriage B, so that molten iron will not be spilled from either of the ladles D or D1. The feature that the surface of the rails 31, 33 of the ladle carriage face downward also prevents the possible deposit of iron on the receiving sufaces which could occur if they were -facing upwards, thus ensuring a smooth ride of the rails over the rollers 35 whose surfaces are protected by the rails.

As will be well understood by one skilled in the art, there is inherent in the operation ofa centrifugal pipe casting machine of this general type, an automatic circuit which controls the movement of the carriage A longitudinally of the tracks, the rotation of the mold, and the extractor, etc.

Tied in with this are special control features according to the invention. For the purpose of explaining these control features, a casting cycle will be considered. A pipe is about to be poured'and the carriage A has come to the up" position. The core 23 is set by mechanism mounted on the carriage A, as for example, mechanism shown in United States Patent 3,168,765 Bernhardt, February 9, 1965. Once the core is set the rotation of the mold is brought up to speed and the ladle D, which is in pouring position tilts automatically. For safetys sake the pouring of the iron does not start automatically when the core goes into position for fear that it might not be properly in position, and, actually, the starting of the pour is by an operator pushing a button. The operator waits till the molten iron starts pouring over the lip of the ladle and, by judgment of the proper timing,

pushes another button to start the carriage A moving from the left to right, referring to FIGURE 3 from the up" to the down" position, and the pipe is progressively poured'..When it reaches this point, the pipe spins while it cools to a certain ladle carried by an overhead crane from a'cupola where the transfer ladle is filled. With ladle D1 .in place, thee'xtrac'tor' is pushed into the end of the pipe after the bell core 23 has been removed. The extractor grips the pipe and the mold carriage A moves uphill again from right to left from down to -up" position and,;at the same time, the pipe is extracted. Once the carriage A is in' the up" position, the cast pipe is transported away sideways to an annealing operation. Then,,while the pipe is cooling, the operator sets another core 23 on the machine and this core is placedinthe end of the pipe in the mold carriage A, and the apparatus is ready to pour another pipe.

There are two limit switches'in the automatic circuit which control the tilt of the respective ladles. If anything goes wrong in the automatic circuit, the ladle will remain in the non-pouring position.

A sliver of iron remains in the bottom of the trough C or Cl as the case may be, after the pouring of the pipe. This has to be removed between pours. As soon as the mold carriage gets clear of the trough which has just been used to pour a pipe, the operator starts working to remove the sliver. The present apparatus permits the sliver to be removed from the trough, which is not in service, just as soon as the previous pipe has been removed from the mold carriage and without holding up the pouring of another pipe. There is no delay in pouring the next pipe, because the two ladles and pouring troughs work independently.

I claim:

1. A centrifugal casting machine comprising, in combination, I

a mold carriage;

tubular mold means rotatably supported on said carriage;

means on said carriage in operative engagement with said mold means for rotating the mold means as it is charged a with a molten metal and for reciprocating the mold means along a-path of travel about which said mold means rotates;

. support means reciprocably restricting said carriage for movement along said path. of travel between an -up" and down' position on said path of travel; and

dual-pouring-ladle means at the up position of said support means whereby said mold means can be im-' mediately charged with molten metal during each cycle between the up and down positions with a minimum expenditure of time and with maximum efficiency;

said dual pouring-ladle means comprising guide track means extending transversely of the up position of said mold means path of travel;

a ladle-support frame reciprocably supported on said guide track means,

powermeans operatively connected to said ladle-support frame for positioning the frame in one of two positions,

a pair of pouring ladles pivotally mounted on said ladlesupport frame on axes of oscillation parallel to said guide track means, a

said pair of pouring ladles being respectively disposed in one of said two positions of said ladle-support frames.

pouring ladles and extending down the path of travel of said mold carriage on said support means and respectively positionable axially within said tubular mold means m relation to one of the positlons of said ladlesupport frame; and

power-tilting means on said ladle-support frame and operatively connected to the respective pouring ladles whereby one pouring ladle and spout can be cleaned and the one ladle can be filled with molten metal while the other pouring ladle can be used to progressively pour molten metal into the tubular mold means as the mold means is moved from .the up" to down positions while the mold means is rotated, and thereafter, after a molded article has been removed, the mold means can be moved axially onto the pouring spout of the one pouring ladle which was subsequently filled with molten metal and molding of another article can be substantially immediately accomplished when the mold means reaches the up position.

2. The combination as claimed in Claim 1, said support frame comprises a pair of depending guide rails disposed in mutually parallel relation and having downwardly-facing running surfaces, guide rollers journaled on axis of rotation normal to the path of movement of said ladle-support frame and engaged by said depending guide rail running surfaces whereby spilled molten metal is substantially eliminated from said rollers and rail running surfaces.

3. The combination as claimed in Claim 2 in which the guide rollers engaging one of said guide rails includes an annular groove for restrictively retaining the rail in its path of reciprocation.

4. The combination as claimed in Claim 1 in which said power means operatively connected to said ladle-support frame comprises a piston-and-cylinder disposed parallel to the guide track means for said ladle-support frame,

the piston being fixedly anchored at one end and including an integral piston defining variable-volume fluid chambers on opposite sides thereof, said piston being fixedly secured to a lower portion of said ladle-support frame, v and a fluid-pressure system operatively connected to opposite ends of said cylinder in spaced relation from the reduced-diameter end portions substantially complementary to the end portions of said piston, and supplemental fluid pressure by-pass lines connected to the terminal ends of the reduced-diameter end portions of said cylinder and said fluid pressure system whereby the terminal travel of said piston relative said cylinder is substantially damped as the frame reaches either of said two positions of orientation.

6. The combination as claimed in Claim 1 in which said support frame includes pairs of vertically disposed, axially-aligned journal portions, said pouring ladles including axially aligned stub shafts respectively journaled in said journal portions, said power-tilting means comprising two independent motor-andspeed reducer assemblies on the frame, a crank arm projecting from the motor-and-speed reducer assemblies, and a force transmitting rod pivotally connected to said crank arm at one end and pivotally connected to a respective powering ladle eccentrically of the axially aligned stub shafts.

ends thereof whereby movement of said piston to the

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