US2126097A - Means for venting core boxes - Google Patents

Description

Aug. 9, 1938. 'H. 1.. DEMMLER 7 2,126,997

MEANS FOR VENTING CORE BOXES Filed April 29, 1937 x2593 142 J2 Z2\ Z0? 5 23 x 13 25 r V I 1i in 1.3 I 15/16 7.5

t k V\ e2 I A Patented Aug. 9, 1938 ED STATES F F! GE,

2,126,091; 7 MEANS- FOR VENTING GOREBO-XES' Henry L. Demmier,, Kewanee, Ill.-

Application' April 29; 1937i SeriaI Nm 139;646

5.- Claims.

My invention relates to molds or core boxes to be used in connection withmold orcore making machines: ofthe' type in which-a mold orcorebox' is clamped-I againsta sand container from which o sand is forced into the moldorcore box bycompressed air.

An object of my inventionis to provide an improved means for venting the compressed? air passing intoa mold or core box, and also the atll mosph-eri'e air which i's-present in an empty mold. or core box, and at the sametime to prevent the escape from the mold or core box of the sand which is forced thereinto;

Another object is toprovide venting means for 1W core boxes which is less liable to become clogged by particles of sand than are the venting means now in use;

Another object is to provide ventingmeans forcoreboxes which can be more easily cleaned of obstructing particles ofsand than are the venting means now used.

Another object is to provide venting means for coreboxes which are more efficient and have a greater capacity than do the venting means now in use.

Another object is toprovide an inexpensiveven-ti-ngmeansfor core boxes which ismore durable and longer-lived than theventing means now used;

Other objects and advantages'will becomeapparent as the description proceeds;

In the drawing:

Figure I is a. vertical sectional view, somewhat diagrammatic; of a core box embodying my invention, in position in a core making machine;

Figure 2 is a View of aninside wall of a core box" incorporating one embodiment of myinvention;

Figure 3 is a section taken onthe line 3-3* of Figure 2;

Figure 4 is a bottom view ofthe structure shown in Figure 3;;

Figure 5' is a sectionaliview, similar to Figure 3, but showing a modified form of my invention; and:

Figure-6 isa sectional view, similar to Figure 3' but showing another modified form of my-invention.

Referring to the drawing; I have illustrated in Figure 1 a machine comprising aframe- I which supports-apressure head 2-. and a sand container 3. It will be understood that the upper end of the sand container is closed, and is provided with pip ing or other suitable means. for supplying compressed air or other pressure. thereto. The sand container is further provided with a re-- 55; movable bottom plate- 1:, provided with a. centrat aperture 5 through which the Saudis forced into the mold; or core box 6.

This mold or core box 6 isshown assupported on bars 1" resting uponthe pressure head.- 2*, which is in the form of'a cylinder slidably mounted on a stationary piston 8. The piston 8- has a vertical bore 9" communicating with a pipe I'D connectedwitha source of compressed airorother'pressure fluid; wherebyfluid under pressure maybe admitted' to. the space between the piston 8 and=cyl*- inder 2 to force the moldor; core boxit firmly against the bottom plate 4' of the'sand' containers;

It will be understood-thatthemold or core box-B maybe of any desired size or'shape, and thatthe number, and arrangement of the ventingmeans willdepend upon the size and shape of the mold or core box. The particularmold orcore boxshown may be. considered as illustrative only, and is pro,- vided with a laterally extending projection H provided with my improved venting means, ind-1*- cated generallyat l-2;. Similarventingmeans-t2: are. also-indicated as being provided in the bottom of the box. These venting means i2 may be of any; of the three types disclosed in this applica; tion.

The particular type of venting means shown in Figures 2;, 3' and 4 comprises a tapered outer sleeve it which has a drive or press fit with .a-wallof the mold or core box 6, it being understood that the term wall is used generically to cover aside, bottom or top part of'the box, orany projection orextension thereof-L This sleeve I3 has a. gen-J erally cup-shaped recess M formed in its innerend, and this cup-shaped recess communicateswith a plurality of bores l5- arranged in the form of a circle about an enlarged central bore l6 which-may be threaded as indicated at I 1;

As best shown in Figure 3, the central bore l6 and most of the cup-shaped recess I4 are filled by a central member I8 having a threaded stem I-EI which coacts with the threads H of the sleeve l3. to securethe member and sleeve together; The member l8 has'a tapered upperend terminating: in an edge 2.! which cooperates with the'adjacent edge 22 of the sleeve F3 to provide a metered annular slot 23 of such size that air can pass therethrough but sand cannot.

The inner surface 24 of the member I 8 is flat; and lies in the same plane as the inner end 25: of the sleeve l3 and the inner surface 26 0-1 the 50.- adjacent wait of the mold or co-re'box d. It will be understood: that where a finegrade of sand isused, the annular slotv 23 must be quite small to prevent: the passage of sand. therethroug-h, whereas when a. coarser quality of sanct is: used, a u.

75,, capacity in a small cavity or corner formed in the.

wider slot may be used without permitting the sand to pass therethrough. I therefore make my venting means adaptable to different qualities of sand by making the member [8 removable and replaceable by a different member having a larger or smaller inner end, so that by providing a plurality of members I8 of different sizes, the mold or core box may be readily adapted for use with different sands. Where the member I8 is screwed into thesleeve I3 as shown in Figure 3, the inner end of the member I8 is preferably provided with a kerf 21 for receiving the end of a screw driver to be used in unscrewing the member I8 from its sleeve I3. This removal and replacement can be accomplished without removingv the sleeve I3 from the mold or core box.

It is important that no projections or depressions be provided on the inner surface of the mold or core box, but that this box have a smooth inner surface exposed to the sand. I therefore find it desirable to fill the kerf 21 with rubber or other suitable material 28 which can easily be removed from the kerf 21 by means of a sharp tool when it is desired to unscrew the member I 8.

I The sleeve I3 and member I8 have their inner ends exposed to the blast of sand entering the mold or core box through the orifice 5, and are thereby subject to a grinding or abrasive action. I therefore prefer to make the sleeve I3 and the member I8 of steel or other suitable wear resisting material, and I prefer to harden the inner ends of the sleeve l3 and member I8 to increase their wear resisting properties. In some instances it is advisable to harden the entire sleeve and the entire member rather than their inner ends only.

While the width of the annular slot 23 is less than the diameter of the grains of sand used in the mold or core box, the annular slot in its entirety provides a relatively large opening through which the air may freely escape from the interior of the mold or core box. The air passing through the slot 23 passes between the upper end of the sleeve I3 and the enlarged head of the member I8, and thence through the bores I to atmosphere. It will be noted that the taper of the enlarged end of the member I8 provides forthe free escape of any particles of sand which may pass through the slot 23, and thereby reduces the likelihood of clogging.

I have found that a slot of a given width and a length several times its width is much less likely to clog than is a circular orifice having a'diameter equal to the width of the slot. Such a slot is therefore far superior to a plurality of such circular orifices, having the same theoretical venting capacity. Furthermore, it is much easier to remove any particles of sand which may become wedged in such a slot than it is to remove particles of sand becoming wedged in such circular orifices.

I The embodiment shown in Figure 5 is identical with that shown in Figures 2, 3, and 4, except that in the embodiment of Figure 5 the member l8A and outer sleeve I3A have a press fit instead of being screwed together as in Figures 2, 3, and 4.

Where the member is press-fitted into its sleeve, it is unnecessary to provide the member with a kerf such as the kerf 2'! of the embodiment of Figure 3.

In the embodiment of Figure 6, greater venting capacity is provided in a small area, and this form of my invention is particularly desirable Where it is essential to provide the maximum venting wall of the mold or core box. In this form of my invention I provide an outer sleeve 30 which is press-fitted into the wall of the mold or core box, as in the previous embodiments. The inner end of this sleeve 30 is provided with a large cupshaped recess 3| which communicates with a plurality of bores 32 arranged in the form of a circle about a large central bore 33.

An inner sleeve 34 is threadedly or otherwise secured in the bore 33 and has an enlarged inner end 35 providing an edge 36 cooperating with the adjacent edge 37 on the outer sleeve to form an annular slot 38, through which the air may escape but which is too small to permit the passage of sand therethrough. The inner end of the inner sleeve 34 is likewise provided with a cup-shaped recess 39 communicating with a plurality of bores 4Il arrangedin the form of a circle about a central bore 4 I. A member 42 is threadedly or otherwise secured in the bore 4| and has an enlarged inner end 43 providing an edge 44 which cooperates with the adjacent edge 45 on the inner sleeve to provide a second annular slot 46 for the escape of air. This slot likewise is too narrow to permit the escape of sand therethrough.

It will be understood that where the member 42 is threadedly secured in the inner sleeve 34, this member 42 is provided with a kerf 41 which may be filled with rubber or other suitable material 43. The inner sleeve 35 may also be provided with holes 49 for receiving the prongs of a tool used in unscrewing this inner sleeve from the outer sleeve 35. These holes 49 may likewise be filled with rubber or other suitable material so that a smooth surface is provided for contact with the sand in the mold or core box.

It is to be understood that my invention is not limited to the particular form shown in the drawing, and that the scope of my invention is to be limited solely by the following claims.

I claim:

7 1. Venting means of the class described, comprising a box, a sleeve press fitted thereinto, said sleeve having a circular recess communicating with a central bore and a plurality of bores grouped about said central bore, a second sleeve located in said central bore and having cooperation with an end of said first named sleeve to provide an annular slot for permitting passage of air therethrough but for preventing passage of sand therethrough, said second sleeve having a circular recess communicating with a central bore and a plurality of bores grouped about said central bore, and a member located in said last named central bore, said member having an end located in said last named recess and cooperating with an end of said second sleeve to provide a second annular slot adapted to permit passage of air therethrough but adapted to prevent passage of sand therethrough.

2. Venting means of the class described comprising a wall member having an aperture therein providing an enlarged portion opening upon a side of said wall member along a well defined edge of predetermined dimensions about a predetermined axis, a second member disposed in said enlarged portion. having an end face and a tapering circumferential face centrally located with respect to said enlarged portion, said tapering face intersecting said end face along a second well defined edge having dimensions corresponding with and slightly less than said first dimensions to provide a clearance between said edges to permit the passage of air therethrough exclusive of core sand, means for securing said members axially 7 relative to each other, and means for connecting said enlarged portion to atmosphere.

3. Vent means of the class described comprising a wall having an aperture therein defining a surface of revolution and providing an enlarged portion opening upon the inside of said wall along a well defined marginal edge and an internally threaded reduced portion opening into said enlarged portion, means for venting said enlarged portion to the atmosphere independently of said reduced portion, and a headed member having a marginally well defined end face threadedly received in said reduced portion to a depth whereby said end face is approximately flush with said wall and the marginal edge of said end face is closely proximate to the marginal edge of said enlarged portion to permit the passage of air therebetween exclusive of core sand, the headed portion adjacent said enlarged portion having a circumferential face defining a second surface of revolution inclined to said first surface of revolution whereby the clearance between. said headed member and said enlarged portion is relieved behind said marginal edges.

4. Venting means of the class described comprising a wall member having a compartment on a side thereof bounded by a well defined edge of a predetermined contour, a second member disposed in said compartment having a tapering face of a cross-sectional contour similar to said first contour, said contours being slightly different as regards their corresponding dimensions to provide a clearance permitting passage of air between said members exclusive of core sand granules of a predetermined size, means for moving one member relative to the other to vary the amount to said clearance, and means for venting said compartment to atmosphere.

5. Venting means of the class described comprising a sleeve, a second sleeve disposed in said first sleeve with sufiicient clearance therebetween to provide a restricted slot permitting passage of air therethrough to the exclusion of core sand, and a member disposed in said second sleeve with clearance between said member and said second sleeve to provide a second restricted slot permitting passage of air therethrough to the exclusion of core sand, means for detachably securing said sleeves together and said members to said second member, and means for venting said slot to the atmosphere.

HENRY L. DEMMLER.

Images