US2607967A

US2607967A - Means for pneumatically casting cores

Info

Publication number: US2607967A
Application number: US114547A
Authority: US
Inventors: William K Springer
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-09-08
Filing date: 1949-09-08
Publication date: 1952-08-26
Anticipated expiration: 1969-08-26

Description

Aug. 26, 1952 w. K. SPRINGER I 2,607,967

MEANS FOR PNEUMATICALLY CASTING CORES Filed Sept. 8, 1949 I I 2 SHEETS-SHEET 1 lnlllll M K 55 g 3nventor 53 5O WILL/AM K. SPRINGER W I J W 52 7 (Ittomeg 26, 19 w. K. SPRINGER 2,607,967

MEANS FOR PNEUMATICALLY CASTING CORES Filed Sept. 8, 1949 2 SHEETSSHEET 2 57 56 37 K48 fi 3 Inventor WILL/AM K. SPRINGER (Ittomeg Patented Aug. 26, 1952 MEANS FOR PNEUMATICALLY CASTING CORES' William K. Springer, Lansing, Mich.

Application September 8, 1949, Serial No. 114,547

2 Claims.

This invention relates to machines for makin sand cores and more particularly to a machine in which the mold for the sand core is filled by sand blown in by air under pressure.

Although the principle of filling a mold with sand by a jet of compressed air is old and hasbeen utilized for many years, the operation of machines designed for this purpose has not been as'efficient as it was hoped the application of this principle would make it. Several features of the heretofore eXisitng designs have contributed to this lack of efiiciency. Amongthese features has been the fact that the mold has always been filled from the 'top. This arrangement requires the hopper of sand, or blowhead, to be placed above the mold, and, as so positioned, it has been necessary to limit the amount of sand in the hopper to that which is necessary to fill each individual mold. This hopper has to be refilled after the packing of each mold, resulting in a time consuming operation.

' Some of-the existing designs for this type of machine utilize a hopper containing sand sufficient for more than one mold. Such machines, however, utilize either a measuring mechanism to carry sand from the hopper to a position in which it can be blown into the mold or a gate arrangement between the mold and the hopper. Both of these arrangements unduly complicate the mold filling machine, particularly the use of the measuring mechanism. The gate arrangement is wastefulof the sand since a certain amount remaining between the gate and the mold is v spilled when the mold is removed.

Where the sand is blown in from above the mold, it is necessary to provide a plate or gate, contacting the mold, having holes coordinated in size and location to those in the mold for introducing the sand into the mold. Unless this plate is utilized, the sand will form piles on the surface of the mold between the holes, which sand will be wasted when the mold is removed. These plates are expensive and a new and different plate 'must be made for each mold since the location of the holes is governed by the size and shape of the core to be molded.

A further difficulty occurring when the mold is filled from above is the creation of pillars of sand in the opening through which the sand is blown into the mold. The mold, when filled, is opened by removal of the top half or cope of the mold, leaving the pillars of sand formed in the gates or sand entry holes projectingfrom the.

sand core. These must be removed before the container in which the sand core is baked is placed over the mold. The removal of these pillars before baking frequently damages the sand core causing spoilation. To overcome this, it .is necessary to turn the mold over and remove the. drag portion of the mold first.

My invention eliminates these difficulties, including the Waste of excess sand, and provides a machine with improved over-all efficiency. Furthermore, myinvention permits a machine of this type to be constructed of a few simple parts which may be swiftly and easily operated'upon'a number of different molds without the necessity of modification or adapter parts.

Therefore, it is a primary object of my inven--.

tion to provide a core mold filling machine in which thesand enters the moldirom the bottom.

It is a further object of myiinvention to provide a core moldfilling machine having a sand hopper capable of retaining sufficient sand to fill several molds and having direct communication with the mold.

It is an additional object of my invention to provide a core mold filling-machine capable of handling a number of molds of differentshapes and sizes without adjustment.

Other advantages of my invention will be seen by those acquainted with the art of sand molding upon reading the following specification and the accompanying drawingsin which: I

Figure l is a side elevation, sectional view of my core mold filling machine.

Figure 2 is a front elevation view of my core mold filling machine.

Figure 3 is a sectional View of the cam for the clamp. of my core mold filling machine, taken along the plane III-III of Figure 1 but showing only the housing in section.

Figure 4 is a sectional view of my core mold filling machine taken along the plane IV-IV of Figure 2.

Figure 5 is a top view of the cover for hopper ofmy core mold filling machine.

Figure 6 is a fragmentary sectional viewof my the core mold filling machine taken along the plane the ring 3 and the housing I.

over the rectangular opening and, thereafter, is retained by a clamp. A resilient gasket, contacting the mold and surrounding the rectangular opening, provides a pneumatic seal. Air, under pressure, is admitted at the top of the hopper for forcing the sand into the mold.

In the following description the terms upwardly and downwardly are frequently used and shall be taken to mean upwardly in the direction of the top of the structure as shown in Figure 1 and downwardly in the direction away therefrom.

Referring specifically to the drawings, the numeral I refers to a tubular housing seated at its lower end in a base 2. A ring 3, having diametritached to the housing I by welding, brazing or any other suitable means of attachment capable of providing a strong and rigid bond between A groove is provided on the external surface of the housing I at its upper end, which groove, together with the ring 3, defines a channel 6. A T-shaped gasket I, having its depending tongue seated in the channel 6, provides a seal between the housing I, ring 3 and cover 8. The

ears

4 and 5 are equipped with circular openings. The opening in the ear 4 has straight internal walls, while the opening in the ear 5 is equipped with threads. The cover 8 has a peripheral outline substantially identical to that of the ring 3 includinga pair of tabs 9 and ID. The cover 8 is mounted to the housing I' by means of a bolt II extending through an opening in the tab 9 and the opening in the ear 4. The bolt II is secured by means of the nut I2. The tab II) has a slotted aperture I3 extending parallelto the periphery of the cover. An. L-shaped handle I4, having a threaded end for engaging the opening in the ear 5, passes through the aperture I3 when the cover 8 is closed. A shoulder I5;0n the handle I4 engages the tab II] as thehandle is rotated, forcing the cover down against the gasket 1 to seal the open end of the housing I.

A conduit I6, having a three-way valve I'I therein, threadedly engages an opening in the Wall of the housing I adjacent the ring 3. The conduit I6 extends through the wall of the housing I to provide communication between the central passage of the conduit and the hopper or chamber I8 of the housing I. The valve IT, in one operating position, admits air by means of the conduit I6 to the chamber I8. In another operating position air in the chamber I8 is permitted to escape through the exhaust port I9. When the mold 27 has been filled, the pressure in the chamber I8 is reduced to that of the external atmosphere by means of this exhaust port [9.

The base 2 includes a shell 26 which forms a supporting stand for the machine and has an upstanding annular collar 2! for receiving the housing I. The housing I is welded, brazed or otherwise suitably anchored to the base 2. Whatever means is used to anchor the housing I to the base 2, that means must effect a tight pneumatic seal between the two parts.

The central opening of the annular collar 2I enters into a passageway 22 extending through the center of the base 2. As the passageway 22 extends through the base 2, it passes through a bend of approximately 180 to terminatein an upwardly opening orifice 23. The cross-sectional shape of the passageway 22 changes from suitable resilient material,

that of a circle adjacent the housing I to that of a rectangle where it enters the orifice 23. The orifice 23 is rectangular in shape, but substantially larger than the passageway 23 to provide a large area of operative contact with the mold 21. Although the shape of the orifice 23 is described as rectangular, it may be shaped in any other suitable manner, such as circular or elliptical, without in any way changing the principle of my invention. A flat platform 24 surrounds the orifice 23, the purpose of which will be described more fully hereinafter. A resilient gasket 25, ex-

tending above the platform 24, is seated within the groove 26 in the base 2 and surrounds the orifice 23. The gasket 25 may be made of any but preferably is formed from rubber. The gasket 25 provides a seal between the mold 21 and the walls of the orifice 23.

The clamping mechanism 28 is adjustably mounted on the housing I by means of the casing 29. The casing 29 consists of a hollow head 30 integral with a bifurcated arm 3I'. The bifurcated arm 3I has a substantially semi-circular sector 32 in each prong of the bifurcated arm, adapted to slidably embrace the housing I. The free end of each of the prongs is equipped with a boss 33. Each of the bosses 33 has a central hole, which hole is threaded in one of the bosses. An L-shaped crank 34, threaded on one end, passes through the 'unthreaded hole in the one boss 33 and engages the threaded opening in the other boss 33. A rib 35, rigidly secured to the crank 34, engages the boss 33 on one of the prongs as the handle is rotated in one direction, urging the prongs together to elfect a clamping action between the sectors 32 and the housing I.

The clamping mechanism 28 includes a shaft ed to the shaft 36 for rotation therewith is a cam 36. The cam 38 is held against movement axially of the shaft 36 by the journals 3'! and is held against movement radially of the shaft by the key 39. One end of the shaft 36 is provided with a slot into which is seated one end of a spiral, coil spring 40. The spring 40 is seated within a circular shell 4| anchored to the adjacent journal 31 by means of screws 42. The other end of the spring 40 is attached to theshell M. The open side of the shell 4| is sealed by a cap 60 pressfitted into the shell 4|.

The other end of the shaft 36, externally of the hollow head 30, passes through a collar 43. Axially aligned holes diametrically through the collar 43 and shaft 36 mount a lever 44 threaded on one end. This hole, in one wall of the collar 43, is threaded to receive the threaded end ofthe lever 44.

The cam 38 has a dwell 45 at its point of greatest radius. A stud 46 is mounted in one shoulder of the cam 38 for opening the herein-- after described switch 41.

The bearing member 48 of the clamping mechanism 28 includes. a plate 49, having a centrally located boss 50, mounted on the end of the rod 5|. The rod 5I is provided with ahemispherical end 52 and an annular channel 53. The blind opening 54 in the boss has a channel in its inner wall aligned with the annular channel 53 in the rod 5I when the rod 5I and plate 49 are assembled. The end of the blind opening 54 has a conical shape to receive the end of the rod 5I. A resilient ring 55 is seated in the channel in the boss 50 and extends partially into the annular channel 53.' Thus, the plate 49 may be rocked in any dire'ction about the end of the rod 5 l inorder that itmay seat securely on 'the top surface of the mold'21 even though this top surface maybe inclined to the "rod 5 l-. I I

- Thee'nd of the 'rod" 5|within the'hollow'head equipped with 'a' dis'c-shaped stop 56. A

spring 51, seated-within the bore '58 in the hollow ber '48. The switch 4 is connected by suitableelectrically 'conductive'wiring,'not illustrated, with a solenoid, also not illustrated. The solenoid operates the valve H to control the entrance of compressed air to the chamber It.

A modification of the base is shown in Figure, 8

I in which the base I 0|] is provided with a channel IUI surrounding the orifice 23 but spaced outwardly'from it a short distance. The channel lfl'l receives the seating gasket I02. This arrangement provides an improved anchor for the gasket I02. The construction'of the gasket I02 is identical-Ito that of thegasket 25 except that its length and width have been increased toaocommodate the relocation of the channel Hll I Operation @Thecov'er B is pivoted about the bolt I I to expose the open end of the housing]. A quantity of sand is poured into the chamber I8 which-acts as a sand hopper. The cover 8 is then pivoted back to close the end of the housing and the handle 14 turned to force the cover 8 down tightly against the gasket by means of the shoulder 15. The interaction of the cover 8 and gasket 1 provides a pneumatic seal at the top of the chamber The vertical position of the clamping mechanism 28 is adjusted to accommodate the size of the particular mold to be filled; This is accomplished by rotating the crank 34 to release the grip of the bifurcated arm 3| on the housing I. The clamping mechanism 28 is then moved along the housing I to the proper position and the crank 34 rotated to lock the clamping mechanism in position.

The mold 21 is placed over the orifice 23 with the sand admitting holes or gates extending downwardly to communicate with the orifice 23. The lever 44 is then rotated downwardly until the dwell 45 of the cam 38 rests upon stop 56. This forces the bearing member 48 down against the mold 21 and presses the mold tightly against the gasket 25 to effect a tight pneumatic seal. At the same time the spring 40 is tensioned to rotate the cam 33 and lever 44 upwardly when they are released. The dwell 45 provides a lock against this action of the spring 43. The existence of the flat platform 24 permits the moldto rest entirely upon the gasket 25 without interference from any other part of the machine.

When the dwell 45 of the cam 38 has engaged the stop 56, the stud 46 contacts the actuating member 59 of the switch 41, closing the switch. The closed switch 41 operates a solenoid to open the valve [1 for admitting air tothe chamber 18. The air admitted by the conduit I6 is under a pressure of approximately 80 to 135 pounds per of theexternal atmosphere.

square inch gauge, but preferably thefpres'su're is;

maintained at about lll'dpounds per squarev inch;

gauge.

The air admitted by. theconduitl it: into the chamber l8 urges sand toward the orifice' '23; The sand immediately adjacent the holes in the mold2'l is' forced by the air pressure into the mold cavity. -When the mold cavity hasbeen filled; the lever 44 is'rotated upwardly S1ig'ht1y.t0diS engage the stud 46' and actuating member.i59. This opens the switch 41, causing the valve -|f1 to shut ofi the supply of air to theachamber IB and at the same time opens 'the exhaust port' 19 toreduce the air pressure in the-chamber to that The movement of the lever 44, although sufiicient to open the switch 41, does'not disengage the dwell 45' of the cam 38 and the stop 56. This permits themold 21'to beheld down against the gasket'25 until the air pressure in the chamber l8 has been reduced. This requires a very short lapse of time. I When the pressurewithin the chamber 1.8 has been reduced to normal, the lever 44 is rotated slightly upwardly to disengage the dwell 45 from the stop 56'. Thereafter thespring 4D automatically rotates the shaft 35, cam 38 and lever 44' upwardly to released or inoperative position. The spring 51 automatically lifts the plate 49 from the mold 21. By utilizing the spring 40 the operator is relieved of the time consuming motion necessitated by rotating the lever 44 upwardly.- Once the operator has exhausted the air from the chamber l8 he merely has to give the handle a slight upwardly push and thereafter the spring carries out the rest of the operation; This leaves the operators hands free to grasp the mold 21 ready to remove it as soon as it is disengaged;

Since the mold 2'! seats down directly over the orifice 23 and any sand which does not enter the mold remains in the orifice, there is no loss of sand when the mold 2'! is removed. There is no tendency for the sand to spill because it has to be moved upwardly to escape from the passageway 22 and orifice 23. Thus, the chamber [8 can be filled with sufiicient sand to fill a number of molds, and the filled molds can be removed and replaced by empty molds without spilling sand and without the necessity of providing only a. measured charge of sand for each individual mold. No parts need to be handled, when changing molds, other than the mold. My invention provides a rapid, simple and sand conserving mechanism for pneumatically filling core molds.

Many modifications may be made without departing from the principle of my invention. Among such modifications is a redesign to lengthen the passageway 22 in order that the orifice 23 may be spaced further away from the housing Such a redesign permits the orifice 23 to be enlarged to accommodate larger molds. Another possible modification involves positioning the hopper or chamber 3 at some angle to the horizontal other than perpendicular.

It is also possible to make the machine substantially automatic. The opening, closing and latching of the cover 8 may be controlled by solenoids. The lever can be replaced by a switch controlling a group of solenoids and re:- lays which would automatically operate the cam 38 and maintain the valve H in open position for a given length of time.

Each of these modifications and others, how ever, do not change the principle of my invention, and each of them is to be considered as included within the terms of the hereinafter ap- 7, pended claims unless the claims by eipr'essly provide otherwise. I

I claim:

1. In a sand core mold filling machine adapted to force sand into a mold, the lower wall of whichmold defines at least one sand admitting opening communicating with the mold cavity'there in, the combination comprising: walls defining a vertical, tubular passageway open at" its upper end,'the upper portion of said passageway being their terms straight; the lower end of said passageway defining an arc of 180 and terminating in an upwardly directed orifice said orifice being substantially in the same horizontal plane as the junction of the arcuate and straight portions of said passageway; a resilient gasket surrounding said orifice a cover closing the upper'end of said passageway; means for intermittently introduc ing a gas under pressure into said'passageway adjacent said cover; clamping means aligned with and above said orifice for holding said mold against said resilient gasket with the opening therein in communication with said orifice, whereby gas under pressure admitted to the upper end of said tube will urge sand in said tube upwardly'through said orifice and said sand admitting opening into said mold cavity.

'2. 'In a sand core mold filling machine adapted to force sand into a mold, the lower wall of which mold defines at least one sand admitting opening communicating with the mold cavity therein, the combination comprising: a housing defining a straight, central, vertical chamber open at each of its ends; a base member-having an internal passageway curved through an arc of substantially 180; a platform on said base defining an upwardly directed orifice therein,

saidnorifice adapted-to communicate with said mold;- one end of said passageway communicat-- ing with the lower'end 'of said verticalchamber,

the other end of said passageway communicat-' ing with said orifice; said orifice being substantially in the same horizontal plane asthe junction of said vertical chamber and said internal passageway in said base member; a cover closing the upper end of said chamber; locking means for'said cover; a conduitfor intermittently introducing air under pressure into said chamber at its upper end; a resilient gasket surrounding said orifice; clamping means adjustably mounted on said housing for clamping said mold over said orifice with said sand admitting opening in communication with said orifice, whereby sand in said chamber will be urged by said air toward said orifice and upwardly into said mold cavity:

WILLIAM K. SPRINGER.

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

UNITED STA ES PATENTS