Semi-automatic Dynamically Balanced Gravity Casting Machine

Abstract

The machine is designed to handle brass molds of the type heretofore operated by hand. A flat rectangular base is provided with end walls which are pivotally mounted so that the machine is dynamically balanced to easily pivot the machine with little effort. A pair of rectangular plates are mounted on edge with opposed faces. One plate is fixed and the other plate is movable. One half of a mold is mounted on each plate face. The plates are water cooled to cool the mold elements mounted thereon. A pneumatic cylinder is provided with a piston rod which operates the movable plate. The cylinder is controlled by a manually operable valve toward the front of the base. By moving the valve handle, the operator can move the movable plate toward the fixed plate to close the mold. Movement in the opposite direction will open the mold. In closed position, the operator ladles molten metal into the mold gate at the top to fill the mold and gate. The control handle is grasped and the operator lifts the handle causing the entire machine to pivot and tilt 90.degree.. This dumps the excess molten metal from the mold gate. The machine is pivoted back to horizontal and the mold is opened. An auxilary plate is slidable mounted behind the movable plate and carries a plurality of knockout pins which are designed to enter openings in the movable plate and mold. The pin plate is held in withdrawn position by springs when the mold is closed. However, when the mold is opened, the movable plate backs into the pin plate to cause the pins to dislodge the molded article from the mold.

Description

BACKGROUND OF THE INVENTION

Brass molds for comparatively small articles molded with "sludge" metal are usually operated by hand. The two mold parts are locked together and held by a handle, usually of thick wood, in a pouring position with one hand. The other hand is used to ladle the hot melt into the gate of the mold. The mold handle is then used to lift the mold to a suitable position over a receptacle and then twist to invert the mold and dump the excess metal from the gate. A tool is now inserted to pry the mold parts apart and remove the molded article. If the mold is a little large and heavy, the operator must work slowly with frequent rests. Often, a larger mold requires the use of two hands for lifting and twisting.

The entire process is slow and tedious. It is extremely tiring so that an operator cannot work at any great production speeds. In molding small articles such as belt buckles, the mold is small and can be readily handled in the conventional manner. However, the larger molds are heavy and clumsy to handle and are the subject of the present invention.

SUMMARY OF THE INVENTION

The machine of the present invention is designed for the effortless handling of the larger, heavier molds, permitting faster operation over extended periods without tiring the operator. First of all, the entire unit is mounted on a base which is dynamically pivotally mounted so that the entire machine can be pivoted through a 90.degree. turn with little effort.

A pair of water cooled plates are mounted with a mold part on each plate in opposed relation one to the other. One plate is fixed and the other plate is horizontally movable toward and away from the fixed plate. A pneumatic cylinder is used to operate the movable plate. A control valve is provided with an extending handle which can be moved horizontally to operate the valve and cylinder. With the molds in closed position, the operator ladles the molten metal into the gate of the mold, filling the mold and gate. The operator then lifts the handle causing the entire machine to pivot through 90.degree. away from the operator, dumping the excess metal from the mold gate. The metal within the mold is almost instantly solidified by the cooling action of the water cooled plates on which the molds are mounted. The operator now tilts the machine back to the horizontal and actuates the valve to open the mold by sliding the movable plate away from the fixed plate. Knockout pins are so positioned that when the mold is opened the pins enter the movable plate to help separate the mold parts and remove the article being molded.

DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a front elevation of a mold machine embodying my present invention with the mold in closed position;

FIG. 2 is an end view of the same taken from the left end in FIG. 1;

FIG. 3 is a front elevation as in FIG. 1 with the mold in open position;

FIG. 4 is a view similar to FIG. 2 with the machine tilted 90.degree. ;

FIG. 5 is a section through the closed mold showing the position of the molten metal in the cavity and gate;

FIG. 6 is a view as in FIG. 5 with the machine in tilted position emptying the mold gate; and

FIG. 7 is a section through one of the plates showing the circulation of the cooling water.

DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 3, a suitable support (not shown) is provided with spaced vertical blocks 10 and 11. Mounted on each supporting block is a bearing support 12 having an adjustable bearing 13 mounted thereon. The machine is mounted on a rectangular base 14 having vertical end plates 15 at each end. A pivot pin 16 extends from each plate 15 and into the bearing 13 to pivotally suspend the base 14 from the bearings 13.

Now viewing the right position of the base 14 in FIGS. 1 and 3, I provide a vertically positioned plate 17 mounted in a fixed position transversely of the base 14. The plate 17 is braced by a plate 18 mounted between the plates 17 and the adjacent end plate 15 at right angles to both plates. The plate 17 is provided with a circuitous channel or opening 19, see FIG. 7, having a lower inlet at 20 and an upper outlet at 21 for the circulation of cold water to cool the plate 17.

Mounted on the left face, FIG. 1, of the plate 17, is one half 22 of a brass mold. The mold 22 is provided with a conventional mold cavity 23 and gate 24, see FIGS. 5 and 6. At the left of the base 14, FIG. 1, a vertical supporting plate 25 is rigidly braced by a plate 26 similar to the plate 18 at the other end and positioned between the plate 25 and the adjacent end plate 15.

Horizontally mounted on the plate 25 is a pneumatic cylinder 27 controlled by a manually operable valve 28. The pneumatic power supply enters the valve 28 through line 29 and is distributed to the rear of the cylinder 27 through the line 30 and to the front through the line 31. The control handle 32 is horizontally movable to actuate the valve and cylinder and move the piston rod 33 to the right or left.

The plate 17 is provided with four pins 34, one adjacent each corner, which extend at right angles to the left in FIG. 1. A plate 35 is slidably mounted on the pins 34 for movement toward or away from the plate 17. The plate 35 is also circulated with a cooling water system in the same manner as the plate 17 as shown in FIG. 7. Water enters the lower inlet 36 and leaves at the upper outlet 37. The other half 38 of the brass mold is mounted on the plate 35 opposed to the half 22. The plate 35 is a movable plate and is coupled to the piston rod 33 for reciprocating therewith.

Now viewing FIGS. 1 and 3, the plate 35 and mold section 38 are provided with a plurality of horizontal openings 39 in which the knockout pins 40 are slidable. The pins 40 are mounted on a plate 41 also slidable on the pins 34. The plate 41 is normally pulled to the left, FIGS. 1 and 3, by a plurality of springs 42 extending from the plate 41 to the fixed plate 25. A stop member 43 mounted on the piston rod 33 limits the movement of the plate 41 to the left. Extending horizontally from the plate 25 are a plurality of knockout rods 44.

Now, with the parts assembled as hereinabove described, the operator moves the handle 32 to the right. This causes the piston rod 33 to move the plate 35 to the right closing the mold parts 22 and 38. Note that in this position, FIG. 1, the plate 41 is drawn away from the plate 35 and the knockout pins 40 are withdrawn.

The operator now ladles molten metal into the mold gate 24, see FIG. 5, filling the mold cavity 23 and the gate 24. The cooling effect of the water circulating through the plates 17 and 35 causes the metal to quickly solidify within the mold but to remain molten because of the bulky quantity at the gate. The operator now grasps the handle 32 and pulls vertically so that the entire machine pivots 90.degree. from the position shown in FIG. 2 to the position shown in FIG. 4. This dumps the molten metal from the gate 24 into any suitable receptacle. The excess metal in the gate is thus quickly removed. The back of the machine is provided with a stop plate 45 extending vertically from the base 14. As the base is pivoted by the operator, the plate 45 will contact the top portion 46 of the support (not shown) to limit the turning movement of the machine to 90.degree. as shown in FIG. 4.

The operator now swings the machine back to the horizontal position shown in FIG. 2 and moves the handle 32 to the left. The piston moves to the left, carrying the plate 35 and opening the mold. The plate 41 contacts the rods 44 in its rearward movement thus holding the plate 41 against the action of the springs 42. As the plate 35 moves to the left, the pins 40 slide into the openings 39 to knock the molded article from the mold.

The operator now again closes the mold and repeats the entire operation. The movement of the mold parts is completely controlled by the operator at the handle 32. The tilting of the machine requires little effort in view of the dynamic balancing of the machine. Thus the operator can keep up a steady production pace with a larger mold without tiring. The manual handling of the mold has been eliminated.

The device is simple in construction and can be easily modified to allow for any size and shape of mold. Other advantages of the present invention will be readily apparent to a person skilled in the art.

Claims

I claim:

1. A mold machine comprising spaced vertical supports, a bearing mounted on each support, a rectangular base having vertical end portions, a pivot pin extending laterally from each end portion into each of said bearings to pivotally suspend said base, a fixed plate mounted on said base, a movable plate on said base slidable toward and away from said fixed plate, a mold having one part mounted on said fixed plate and the other part mounted on said movable plate, means for moving said movable plate toward said fixed plate to close said mold and for moving said movable plate away from said fixed plate to open said mold, said means comprising a pneumatic cylinder mounted on said base, a piston rod extending from said cylinder and attached to said movable plate, a control valve mounted at the front of said base for controlling said cylinder, and a manually operable handle extending from said valve, said machine being dynamically balanced between said support bearings, said mold having an upper gate for filling said mold with molten metal, said machine being pivotable 90.degree. to dump the excess metal from said gate, whereby said dynamically balanced machine may be pivoted by manually pushing on said control handle.

2. A mold machine as in claim 1, wherein said fixed and movable plates are provided with circuitous channels therethrough, and means for circulating cooling water through the channels.

3. A mold machine as in claim 1, wherein said mold is provided with means for limiting the pivoting action of said machine to 90.degree..

4. A mold machine as in claim 1, wherein said movable plate and mold are provided with knockout openings, knockout pins adapted to enter said openings to dislodge the article being molded, and means for pushing said pins into said openings on opening of said mold, said means including an auxiliary plate mounted behind said movable plate, said knockout pins extending from said auxiliary plate, a plurality of spings to withdraw said auxiliary plate and pins from said movable plate when said mold is in closed position, and a stop member for limiting the rearward movement of said auxiliary plate and push said pins into said movable plate and mold when said mold is being opened.