US1290161A - Molding-machine. - Google Patents

Description

J. N. FRANT Z. MOLDING MACHINE.

APPLICATION FILED JUNE 2.19)].

1,290,161. Patented Jan. 7,1919.

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JEROME FRANTZ, 0F NEWARK, NEW JE sEY, ASSIGNOR TO THE FOUNDRY APPLIANCE COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

MOLDING-MACHINE.

Specification of Letters Patent.

Patented Jan; 7, 1919.

To all whom it may concern:

Be it known that I, JEROME N. FnAN'rz, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Molding-Mas chines, of which the following is a specification.

My invention relates to molding machines of the type in which power is applied by air or other fluid pressure to ram up the sand in the mold. In such machines, the support or table on which the flask is mounted is commonly raised by air pressure acting on a piston until a pressing or squeezing plate at the top has entered the top of the cope and pressed down the sand. This pressure should be maintained with considerable uniformity until the molding operation is completed, after which the pressure is released to permit the support to descend, afterwhich the part-s of the flask may be separated and the pattern removed. The raising of the support and the maintenance of pressure during the squeezing operation are commonly caused by operation ofa hand lever controlling a valve in'the air or fluid-pressure admission pipe. Because of leakage in the connections, it is usually necessary to keep the air admission valve slightly open during the squeezing, as otherwise the pressure on the sand will decrease. This entails an extremely delicate manipulation of the air control. lever, and it isalmost impossible to maintain uniform pressure by this means.

I have overcome this difliculty by providing a cam which may be operated by a handwheel, Or the like, and which is positioned to bear upon the control lever of the air valve when it is desired to accurately adjust the amount of opening of the air valve. Thus the cam may be adjusted until the amount of opening of the air admission valve is exactly enough to compensate for leaks and to hold the pressure on the sand uniform, the cam being left in this position until the end of the squeezing operation. At this time, the cam may be rotated or otherwise moved to remove its pressure from the hand lever when the admission valve is tightly closed by spring control or otherwise, and-the flask suppgrt is lowered by reducingthe pressure in the cylinder as by opening an exhaust valve. The object of my invention is to provide devices of the character referred to either in complete machines or as attachments to existing molding machines.

In order that a clearer understanding of my invention may be had, attention is hereby directed to the accompanying drawings forming part of this application and illustrating certain embodiments of my inven tion. In the drawings Figure 1 represents a front elevation of a molding machine equipped with my invention, Fig. 2 is a side elevation of the same and Fig. 3 is a horizontal section taken on line 3--3 of Fig. 2.

Referring to the drawings a molding machine is shown comprising the air cylinder 1 within which operates the piston 2 carrying the support 3. The drag 4 of the flask is supported upon or above the support 3 as by mounting the same onthe horizontally movable table 5 which is carried by support 3. The other members of the flask, namely, the pattern plate 6 and the cope 7 are adapted to be mounted above the drag.

The two cross beams 8, 8 carry a pressing plate 9 which is adapted to enter the top of the cope when the support 3 is raised to ram the sand in the mold. Cross-bars 8, 8 are carried at an adjustable height above the floor on the vertical arms 10 which may be pivoted at theirlower ends, as shown at 11, to permit the cross-bars 8 being swung out of the way, the above construction all being common. a

Fluid-pressure is admitted to cylinder 1 to raise piston 2 by means of a pipe 12 which enters the lower part of the cylinder, as shown at 13. A valve chamber 1 1 is provided in this pipe within which operates a valve' 15 of the puppet type, this valve having vertical stem 16 extending upwardly through a suitable opening in the valve chamber. The upper end of the stem is pro vided with a cap 17. A spring 18 surrounds the valve stem between the lower surface of cap 17 and the upper surface of the valve casing and tends to normally hold the valve in its raised or closed position in which it seats tightly against its valve seat 19.

A hand lever 20 is pivoted at one end at 21 to a standard 22 and carries a lug 23 which is adapted to press on the top of the cap 17 to open the valve against the pressure of spring 18. In the form of machine illustrated, the vertical arm 10 adjacent the hand lever carries aplate 24: which is adapted to prevent the operation of the hand lever when the arms 10 are swung out of the vertical position. When arms 10 are in their upright position, however, "lug 23 on the hand lever clears the end of plate 24, so that the valve can then be operated by the hand lever. The cap 17 carries a pair of lugs 25 which straddle the standard 22 and guide the valve in its movement. Air may be exhausted from cylinder 1, when valve 15 is closed, through the admission pipe as far as the valve chamber and then through passage 26 in stem 16, to an exhaust opening 26 in cap 17. The elements described are all of well known character.

The cam shaft 27 is mounted for rotation in a bearing 28 having an arm 29 integral with a clamping plate 30 which is secured to the vertical arm 10 at an adjusted height. The cam shaft carries at its outer end a hand-wheel 31 and at its inner end the cam 32 which is adapted to bear on the upper surface of the hand lever. In the position indicated in the drawings, the rounded lower surface of the cam is in contact with the upper surface of the hand lever, which is accordingly depressed a slight amount to maintain the valve sli htly away from its seat 19. In operating the machine, the hand lever may be depressed by the operator to fully open the valve until the flask has been raised nearly to its upper position, after which the hand-wheel 31 may be adjusted to admit the air at a lesser rate until the pressing plate 9 has entered the top of the cope a desired amount. Hand-wheel 31 is then adjusted until the piston 2 is maintained in exactly the desired position, which means that valve 15 is open an amoimt which is just suflicient to counterbalance the leakage of air in the system. This may be done very readily because of the fact that the spring 18 holds lever 20 constantly in contact with the cam and the effective diameter of the cam increases by slight increments as it is rotated. A delicate adjustment of the position of the valve may be achieved in this manner, which is quite impossible when the operator has to rely on the manipulation of the hand lever alone. When the pressing operation is completed, the hand-wheel 31 may be rotated until the position of the cam has been reversed, so that the flat side comes at the bottom, allowing the hand lever torise sufficiently to entirely closevalve 15, after which the air may be exhausted from the cylinder to lower the flask.

It is obvious that my invention is not limited to the exact details of construction described, but that it relates more broadly to a means of control comprising a cam or the like for moving by successive increments a valve which is part of a means for regulating the fluid pressure acting on the piston.

The described control may be of service not only in holding the piston raised during the squeezing operation, but also in some machines in controlling the subsequent stripping of the cope from the pattern plate. This is often accomplished by gradually lowering the support with the drag and pattern plate, while the cope is held up by various means. My described mechanism may be used to control the lowering of the piston in such a case, for example.

What I claim is 1. In a molding machine, the combination of a cylinder, a piston therein, a pipe for supplying fluid-pressure to said cylinder, to move said piston, a valve in said pipe, a lever adapted to operate said valve, a cam positioned to control the operative position of said lever and thus to operate said valve, and manual means for operating said cam, substantially as set forth.

2. In a molding machine the combination of a cylinder, a piston therein, a pipe for supplying fluid-pressure to said cylinder, to move said piston, a valve in said pipe, a spring tending to hold said valve closed, a hand-lever adapted for actuation to open said valve, and a cam positioned to bear on 7 said lever, when the cam is operated, to actuate said lever by successive increments, against the pressure of said spring, substantially as set forth. 7

3. In a molding machine the combination of a cylinder, a piston therein, a pipe for supplying fluid-pressure to said cylinder, to move said piston, a valve in said pipe, a spring tending to hold said valve closed, a hand-lever adapted for actuation to open said valve, a rotatable cam mounted across said lever to bear on the same, when the cam is rotated, to actuate said lever by successive increments, against the pressure of said spring, and a hand-wheel for rotating said cam, substantially as set forth.

This specification signed and witnessed this 31st day of May, 1917.

JEROME N. FRANTZ.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. 0."

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