US1768960A - Molding machine - Google Patents

Description

July 1, 1930. c. G. KELLER 1,768,960

MOLDING MACHINE Filed April 16, 1929 N V E N TO R [Izarleg idler BY M M A ORNEYS Patented July 1,- 1930 UNITED STATES PATENT OFFICE CHARLES e. KELLER, or rouenxnarsm, NEW YORK MOLDING MACHINE Application filed April s,

This invention relates. to molding machines, and particularly to the jolt roll-over type of machine; In that type, the flask is placed around the pattern, the sand packed about the pattern, and the bottom board placed on top over the sand entry side, the bottom board and flask being later forced together.

It is common practice to place a riser pat- 0 tern on the main pattern and of such height that its upper end terminates below the upper surface of the flask.

7 After the compression of the sand by the forcing of the bottom board'and. flask into contact with each other, it is necessary to diginto the sand to find the endof the riser pattern and pull the latter out. This requiresthe removal of some of the sand and makes the end of the hole through which the riser pattern is withdrawn, comparatively large. I

It is not possible to make the ordinary riser pattern of such height that'it will be flush with the upper side of the flask,"because sand on the upper'end of the riser pattern will prevent the flask and bottom boardfrom being forced together" and also cause a strain on the main pattern.

The object of my invention is to provide an improved construction of riser pattern whereby the riser maybe made of such height that its upperend comes flush with the upper side of the flask, and whereby the compression of sand between the upper end 7 of the riser pattern and the bottom board is prevented. '1 V y With: my improved construction the removal of thezhottom,board leaves the end of the riser pattern exposed so that it may be pulled, outflwithout digging into the sand and without making any enlargement of the hole. T

In carrying out my invention I provide a riser pattern witha chamber or. cavity which is-openiat it'supper end and is dejriser pattern.

lustrated one embodiment of my invention 1929. Serial No. 355,622.

fined by walls which are comparatively thin at their upper edges so that in the forcing of the bottom board and the flask together the sand between the upper end of the riser pattern and the bottom board, may be compressed within instead of on top of the riser pattern, and the flask andbottom boardmay be brought together with the bottom board also contacting with the end of the The details of construction of the riser pattern whereby this result is accomplished may be varied within comparatively wide limits, and the detailsof the riser pattern will also vary with the character of the an flask and main which it is used.

My improved riser pattern may be used with other types of molding machines, but, it v has its main utility in the roll-over squeeze type. Obviously my invention is not limited pattern in connection with to any'of the details of construction of such a machine. 7 r

In, the accompanying drawings I have ilas applied in one form of-the jolt roll-over squeeze type of molding machine.

'In these drawings: I

Fig. l is a vertical section showing the parts in the position which they occupy after the application of the bottom board and before the roll-over and squeezing of the sand;

Fig. 2 is a similar section showing the parts after the flask has been rolled over, and after the sand has. been squeezed or compressed to final position; and

.Fig. 3 is a perspective view of the riser pattern shown in Figs. 1 and 2.

In the machine illustrated, the flask 10 is 9 mounted, upon a pattern. stool '11, and the latteris carried on a roll-over bed 12 which latter is mounted for rotation about,trun- 'nions 13. The pattern leis attached on the pattern stool and the flask'is filled with sand or any equivalent material used in making molds for casting. Upon the pattern 14 is placed one or more riser patterns, the construction of which will be disclosed hereinafter The upper end of the riser pattern is substantially flush with the upper surface of the flask, and such an amount of sand is put in as will come somewhat above this upper surface. The excess amount being dependent upon the size of the pattern and the compressibility of the sand. Upon the sand is placed the bottom board 17 which is held in place in respect to the bed 12 by pivoted.

clamping arms 18.

The bed and the parts carried thereby are rolled over to the position shown in Fig. 2, and the bottom board is brought to a position directly over a vertically movable squeeze head 19. This is forced upwardly by air or other pressure to compress the sand and to bring the bottom board into contact with the surface of the flask, as is illustrated. At a later stage in the operation the squeeze head is lowered, carrying with it the flask and bottom board, thereby drawing the main pattern from the mold. The mold is conveyed on thebottom board to an air hoist or the like and lifted up to such height above the bottom board that a bar or the like may be placed down through the pattern side of the mold to push out the riser patterns which drop from the bottom of the mold. y

As the important feature'of my inven tion the riser pattern 16 is made with a chamber or cavity 20 in its upper or free end, and the upper edge 21 of the peripheral wall defining this cavity is made comparatively thin. Also the riser pattern is made of such height that it will extend from the main pattern to the plane of the upper surface of the flask. As the flash is filled with sand, as shown in Fig. 1, some of the sand will enter the riser pattern and the remainder will be around the riser pattern, as is illustrated. During the compression action exerted by the squeeze head, the sandwhich is within the riser pattern is compressed substantially the same as that outside of the riser pattern, and there is nothing to prevent the bottom board from coming into direct contact with the end of the riser pattern, as shown in Fig. 2. Thus when the bottom board and flask. are later separated the end of the riser pattern will be substantially exposed. Thus it is not necessary to dig around in the sand to find it, and its removal does not necessitate removing any of the sand in the flask other than that whichis inside of the riser pattern itself.

In the drawing I have shown a riser pattern including a lower head portion '22 of frustro conical form, and a tubular or annular' wall 28 which telescopes onto a short 'ternally'so as to facilitate its withdrawal from the mold, and it is likewise preferably tapered internally to facilitate the removal of the sand from the inside of the riser pattern; Although the body of the riser pattern may be cylindrical or of any other desired cross-section, it is preferablv rectangular as shown particularly in Fig. 3. Thls rectangular form in many cases permits of a more effective positioning of the riser pattern in respect to other parts of the casting. The riser attern is preferably of such diameter that a 'ter the pouring, the center portion of the metal may remain fluid for such time as will permit flow to take up for expansion or contraction ofthe metal forming the body of the casting.

Having thus described my invention, what I claim as newand'desire to secureby Letters Patent is: I v V 1. A molding machine, including a flask adapted to receive a pattern and molding sand, and a riser pattern of such height that it extends from, the main pattern to the plane of the upper surface of the'flask, the upper end of the riser pattern having an open ended chamber.

2. A riser pattern forthe roll-over squeeze type of molding machine, including a body portion having a chamber or cavity therein open at the upper end of the riser pattern.

3. A riser pattern for the roll-over squeeze type of molding machine, including a body portion having a chamber or cavity therein open at the upper end of the riser pattern, surrounded by comparatively thin walls whereby sand may be compressed into and outside ofthe riser pattern by the bringing together of the flask and bottom board.

' at. .A riser pattern for the roll-over squeeze type of molding machine, including a hollow cylindrical body portion open atthe upper end and closed at the lower end, the height of the riser pattern being such that when in position on: the main pattern its upper end is substantially in the plane of the upper surface of the flask.

5. A riser pattern for roll-over squeeze type of molding machine, including a hollow tubular body portion open at the upper end and having a separate head of frustro conical form on'the lower end.

6. A riser pattern for the roll-over squeeze type of molding machine, including a hollow tubular body portion open at the upper end and having a separate head of frustro

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