US2088123A - Apparatus for molding - Google Patents

Description

July 27, 1937. M. E. ToMAN APPARATUS FOR MOLDING Filed May 27, 1935 3 Sheets-Sheet l IJuly 27, 1937.

M. E. TOMAN APPARATUS FOR MoLDxNG Filed May 27, 1935 VI5 Sheets-Sheet 2 Mir/Zee( Y Rizza,

July 27, 1937. M. E. roMAN 2,088,123

APPARATUS FOR MOLDING.

Filed May 27, 1935 3 Sheets-Sheet 3 Hummm@ PatentedcJuly 27, 1937y UNITED STATES 2,088,123 APPARATUS Fon MoLnmG Michael E. Toman, Berwyn, Ill., assignor to Castings Patent Corporation, a corporation of Illinos Application May 27, 1935, Serial No. l23,677

Claims..

ing material such as asbestos fiber or rubber is placed against the top or bottom side of the mold or sheets or pads of such material may be placed on both the upper and bottom sides of the mold. The` mold with its sheets or pads is then inserted and clamped between two plates under pressure. The yielding material, which is preferably resilient, permits or causes the two parts -of the mold to yield or flex, if necessary, to bring the parting surfaces of the mold members into full and complete contact with each other. This insures that the casting obtained from the mold will not have any appreciable fin at the parting line.

Other objects and advantages will become apparent as the following detailed description progresses, reference being had to the accompanying drawings, wherein- Fig. 1 is a front elevation of apparatus for holding a mold, under pressure, during. the molding operation.

Fig. 2 is a section taken on line 2--2 of Fig. 1.v

Fig. 3 is a section taken on line 3-3 of Fig. 1. Fig. 4 is an enlarged fragmentary section taken on line 4-4 of Fig. 1.

Fig. 5 is a section taken on line 5-5 of Fig. 4. Fig. 6 is an enlarged fragmentary section taken on line 6 6 of Fig. 1.

Fig. 7 is a longitudinal section taken through a sheet or a pad of yielding material, which sheet or pad embodies a modified form of the invention. Fig. 8 is a longitudinal section taken through a sheet or pad of yielding material, which sheet y or pad embodies another form of the invention.

Fig. 9 is a fragmentary central section taken through apparatus embodying another form of the invention.

Fig. 10 is a perspective view of a hollow sheet metal pad which embodies still another form of the invention, and

Fig. 11 is a section taken on line H-ii of Fig. 10.

rlihe apparatus shown in the accompanying drawings is particularly adapted to be employed Rtlssutn MAYJ 2 1 1940 (ci. zz-so) M in connectionwith molds formed from calcined gypsum, asbestos pulp and water. The pattern is usually formed in metalupon a metallic match plate, the as'k being secured to the match plate and being provided with a cover plate. The ma- 5 terials from which the mold is to be formed are preferably placed therein and violently agitated after which the mold is permitted to set. The mold is then removed from the flask and is subjected to a drying operation. The dried mold is 10 extremely porous and when fused metal is poured into it, the lgases evolved during` the pouring operation vent through the body of the mold. Of course, it is readily understood that the mold is made in two or more parts separately formed 15 in suitable flasks which may be identical with each other in construction.

It may be mentioned at this point in the description that during the drying operation, the molds have some tendency to warp and, in some 20 instances, different parts of the mold shrink different amounts. It has been found that when the parting faces of the two halves of a mold are not exactly complementary to eachother, the metallic casting obtained from the mold will 25 oftentimes have a iin which must be removed. This, of course, increases the cost of producing castings in' quantity as each individual casting must be handled during the operation of removing the fins. 30

As indicated above, the mold members are removed from the flasks before they are assembled for the pouri'ng operation. In fact, it has been found preferable to remove them from the flasks before the drying operation. When a mold is to 35 be poured, the bottom member of it may be placed upon any suitable support and the top member is then placed upon the lower member and subjected to pressure so that the two parts of the mold will not separate during the pouring opera- 40 tion.

Referring now to Figs. 1 to 6, inclusive, wherein improved apparatus embodying the invention is disclosed, the reference character lil designates generally a frame which comprises legs i i adapt 45 ed to support the apparatus upon any suitable support such as a foundry floor. The upper ends of the legs are tied to each other by cross members i2 and i3 and extending upwardly from the cross members i3 are uprights l5 which are bolt- 50 ed at their upper ends to a cross member it. The ,frame is strengthened by relatively large plates iwhich are bolted to some of the crossmembers i3 and to the uprights i5.

The cross members i2 carrying a plate 2t 55 adapted to support the molds during the pouring operation. In Figs. 1 to 6, inclusive, a mold is identified generally by the reference character 22 and comprises a bottom half or member 23 and a top member or half 24, the mold being formed with the usual mold cavity 25 and a pouring passage or sprue 26. In this instance, part of the mold cavity 25 is formed in the mold member 24 and part in the mold member 23. However, in some instances, the mold cavity is formed entirely in one of the mold members a1- though the mold cavity is closed by the other mold member.

A pad 30 is disposed between the plate 20 and the bottom surface of the mold 22, a similar pad 3| being vinserted between the top surface of the mold 22 and a relatively heavy plate 33 which is provided with an aperture 36 adapted to receive a sprue member 31 having a passage which communicates with the sprue 26. It will be noted that the plate 33 is provided with an annular shoulder 38 which engages a similar shoulder on the sprue 31 and holds the sprue 31 in contact with the top surface of the mold member 24.

Abutting against the top surface of a boss 40 formed integral withAthe plate 33 is a plunger 42 which projects from the bottom end of a vertically disposed cylinder 43 depending from and secured to the cross member I6. 'I'he upper end of the plunger 42 is secured to a piston 45 slidably journaled in the piston and urged upwardly by a. compression spring 46. The upper end of the piston 43 communicates through a tube 49 With a port 50 in a valve casing 5| provided with additional ports 52 and 53, the port 53 being an exhaust port. A valve plug (Figs. 1 and 6) rotatably journaled in the valve casing 5| and adapted to be displaced angularly by a lever 51 is provided with a passage 58 extending diametrically thereof and adapted to connect the ports 50 and 52 to each other. The valve plug 55 has another passage 59 communicating with the passage 58. The port 52 is` connected to any suitable supply (not shown) of uid under pressure by a pipe 60. When the valve plug is in the position wherein it is shown in Fig. 6, the,

fluid, under pressure, will flow from the pipe 88, the port 52, the passage 58, the port 50 and thence through the tube 49 to the cylinder 43 to force the piston 45 and the plunger 42 downwardly against 'the action of the spring 45. Ex-

` cellent results have been obtained when the apparatus is adjusted so that the mold is subjected to a pressure ranging from 1.5 pounds per square inch to a pressure of 2.5 pounds per square inch. Of course, the mold is subjected to this pressure during the pouring operation and during the initial cooling operation.

After a mold has been poured, the valve plug 55 is displaced in a counter-clockwise direction (Fig. 6) so that the outer end of the passage 53 communicates with the port 50 and one end 'of the passage 58 communicates with the exhaust port 53. The valve plug 55 then shuts oi! the supply (not shown) of uid under pressure and permits the piston 43 to exhaust through the tube 48, the port 50, the passages 59 and 58, and thence through the exhaust port 53. This permits the spring 46 to elongate and lift the plunger 42 from the plate 33 so that it may be removed.

The pads 30 and 3| may be formed of various yielding substances or yielding members. In that form of the invention illustrated in Figs. 1 to 6, inclusive, the pads 38 and 3| are formed aoaaiae of relatively thick sheets 'i6 -of sponge rubber, each sheet 'l0 being faced on one side by a sheet of asbestos 12, the asbestos sheets 12 abutting against the adjacent surfaces of the mold 22 and protecting the rubber sheets 10 from the heat of the fused metal introduced into the mold cavity.

In practice it has been found that the yielding pads 30 and 3| will function in such manner that if the mold members set and dry so that the parting line between the mold members 23 and 24 do not contact each other throughout when one is placed upon the other, the pads 30 will yield where the mold members contact each other and will aid in flexing the mold members into shapes wherein the entire parting surfaces thereof contact wlth each other. Oi course, when the yielding members are formed of sponge or relatively soft rubber, they yield a relatively large amount when they are subjected to the pressure set forth above..

'I'he operation of the apparatus illustrated in Figs. 1 to 6, inclusive, is substantially as follows: After the mold 22 has been formed in the manner described above, the two parts 23 and 24 thereof are assembled with the pads 38 and 3| and inserted between the plates 20 and 33, the plate 33 being lifted from a suitable bench, or the equivalent, and placed upon the pad 3| with the sprue member 31 in place. The valve plug 55 is then adjusted so that the fluid, under pressure, exerts its force upon the plate 33 and clamps the mold members 23 and 24 and the pads 30 and 3| between it and the plate 20. The fused metal is then poured into the mold in the usual manner and after it has set and cooled a sufficient length of time, the valve plug 55 is displaced angularly so that the fluid, under pressure, will be exhausted from the cylinder 43, whereupon the spring 46 will elongate and move the plunger 424 upwardly. The plate 33 may then be removed from the mold and the mold may be placed upon any convenient support until it is to be broken to remove the casting therefrom.

It has been found that when molds are produced by practicing the method described above, they are substantially free from fins at the parti ing line or lines.

In Fig. 7, a pad 30a formed of asbestos ilber is shown. This pad may be employed inplace of either of the pads 30 or 3| described above. The pad 38a is formed'from braided asbestos ber.

In Fig. 8, a pad 30h is shown which may be employed in place of the pads 30 and 3l.` 'I'he pad 38h is formed from rubber. It is readily understood that the pads 38a and 38h maybe superimposed upon each other and employed in place of the pads 30 and 3| described above.

In Fig. 9, a mold' 22e identical with the mold 22 is shown. -The mold 22c comprises mold members 23c and 24c formed of calcined gypsum, asbestos pulp and water. In this instance as in the instance described above, substantially all the free water and a relatively large part of the water in chemical combination has been removed from the mold members 23o and 24c during the drying operation so that they are extremely porous. The bottom mold 23c rests upon a relatively thin sheet metal plate 8l which forms a closure for a chamber 3| connected to any suitable source (not shown) of fluid under pressure through a valve 32. In some instances, the` chamber Il will be nlled with compressed nir to a suitable pressure and in other instances. the chamber 3| will be filled with water. However, it is contemplated that in both instanc the sheet metal member Il will flex and function in the same manner and for the same purpose as the pads 30 and 3i described above. The upper mold member 24e has a weight 85 resting upon it, which weight is apertured to hold the sprue member 86 having the same function as the sprue member 31 described above.

In Figs. and 11, another embodiment of the invention is illustrated. Thus, a hollow metallic pad is designated generally by the reference character 90 and comprises top and bottom walls 9i and 92, respectively, which have their marginal portions welded to each other. The walls 9| and 92 are formed froinrelativelyy thin sheet metal and form a chamber 93 into which compressed air or water may be introduced through a pipe 95. It is contemplated that the pad 90 may be employed in place of the pads 30 and 3| and that it will yield and function in substantially the same manner as the pads 30 and 3l.`

While I have shown and described certain embodiments of my invention. it is to be understood that it is capablel of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as permissible, in View of the prior art.

1. Apparatus for clamping complementary mold members against each other for the pouring operation, which apparatus comprises a rubber pad, and means acting through said rubber pad for forcing the mold members against each other to have the parting surfaces thereof held firmly in contact with each other around the mold cavity, said rubber pad yielding unequally as necessary in different parts thereof to compensate for faults in the mold members.

2. Apparatus for clamping complementary mold members against each other for the pouring operation, which apparatus comprises an asbestos pad, and means acting through said asbestos pad for forcing the mold members against each other to have the parting surfaces thereof held firmly in contact with each other around the mold cavity, said asbestos pad yielding unequaily as neces-y sary in different parts thereof to compensate for faults in the mold members.

3. Apparatus for clamping complementary mold members against each other for the pouring operation, which apparatus comprises a pad of resilient material, and means acting through said pad for forcing the mold members against each other to have the parting surfaces thereof held firmly in contact with each other around the mold cavity, said pad yielding unequaily ask necessary in different parts thereof to compensate for faults in the mold members.

4. Apparatus for clamping complementary mold membersagainst each other for the pouring operation, which apparatus comprises a padlike member which "is compressible in substantially all parts thereof, and means acting through said pad-like member for forcing the mold members against each other to have the parting surfaces thereof held firmly in contact with each other around the mold cavity, said pad-like member yielding unequaily as necessary in different parts thereof to compensate for faults in the mold members.

5. Apparatus for clamping complementary mold members against each other for the pouring operation, which apparatus comprises resilient means acting on a surface of one of said ent parts thereof to compensate for faults in the y mold members. 6. Apparatus for clamping complementary mold members against each other for the pouring operation, which apparatus comprises resilient means having a large area acting on a surface of one of said members, said area being at least as large as the area of the mold cavity at the parting line between the mold members, and means acting through said resilient means for forcing the mold members against each other to contact parting surfaces thereof held firmly in contact with each other around the mold cavity, said yielding means yielding unequaily as necessary in different parts thereof to compensate for faultsin the mold members.

7. Apparatus for clamping complementary mold members against each other for the pouring operation, which apparatus comprises a hollow member, and means acting through said hollow member for forcing the mold members against each other to have the parting surfaces thereof held firmly in contact witheach other around the mold cavity, said hollow member yielding unequally as necessary in different parts thereof to compensate for faults in the mold members.

8. Apparatus for clamping complementary mold members against each other for the .pouring operation, which apparatus comprises a. member including a flexible sheet of metal, and means acting through said flexible sheet of metal for forcing the mold members against each other to have the parting surfaces thereof held firmly in contact with each other around the mold cavity, said flexible sheet of metal yielding unequaily as necessary in different parts thereof to compensate for faults in the mold members.

9. Apparatus' for clamping complementary Vmold members against each other for the pouring operation, which apparatus comprises a layer of yielding material, and means acting through said yielding material for forcing the mold members against each other to have the parting surfaces thereof held rmly in contact with each other around the mold cavity, said yielding material yielding unequaily as necessary at different points to compensate for faults in the mold members.

10. An apparatus for clamping complementary mold members against each other for the pouring operation, said apparatus comprising spaced clamping members receiving the complementary mold members therebetween, one of said clamping members having a sprue opening therein, said apparatus comprising a pad of resilient material interposed between one of said clamping members and the mold members, said pad being normally of even thickness over its active area, but being yieldable unequaily as necessary in different parts thereof to compensate for faults in the mold members.

MICHAEL E. TOMAN.

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