US3034177A - Molding apparatus and method - Google Patents

Description

May 15; 1962 c. HOOPER 3,034,177

MOLDING APPARATUS AND METHOD Filed July 30, 1959 2 Sheets-Sheet 1 E .2. E0. 5. 1 1m. 4

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24/ 150M420 C. Ho s/2 May 15, 1962 1.. c. HOOPER MOLDING APPARATUS AND METHOD 2 Sheets-Sheet 2 Filed July 30, 1959 INVENTOR. Z60/VAEO C HOOPP United States Patent F 3,034,177 MOLDING APPARATUS AND METHOD Leonard C. Hooper, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed July 30, 1959, Ser. No. 830,652 8 Claims. (Cl. 18-40) This invention relates to the molding of solid objects from molten materials. More particularly, the invention relates to a new method and apparatus for molding articles that are free of surface flaws and defects.

In the casting and molding of detergent bars as described in the copending application of Olle I. Lundberg and Joseph Blinka, Serial No. 816,778, filed May 29, 1959, now Patent No. 2,987,484, which is also assigned to the assignee of the present invention, it was found that the use of old and well known molding equipment would sometimes produce surface flaws and defects on the finished bars. These undesirable results were partly caused by the use of ordinary valves, gates and spurs which form an integral part of conventional, present day casting equipment. It has been theorized that these faults were also due in part to the comparatively small openings that are employed with conventional molding equipment as this results in high flow velocities of the molten material. High fiow velocities are known to be a factor in the formation of flow line defects on cast products. I

It is, of course, desirable to eliminate surface flaws and defects in the casting of articles from any molten material and it will be understood that the present invention was made ot overcome such difiiculties generally and is not necessarily limited to the casing of detergent bars. For convenience, however, the invention will be described as applied to the casting of detergent bars as this is one area in which the invention has been found to have great utility.

An object of this invention is the simplification of conventional casting apparatus and methods by the elimination of valves, gates, and spurs thereby substantially eliminating this source as a possible factor in the formation of surface flaws and defects on finished articles when cast.

A further object of this invention is the provision of a new casting method and apparatus which employs a comparatively large filling orifice thus allowing injection of the molten material at low velocities and at comparatively high volumes per unit of time this being the ideal condition for minimizing flow line defects.

A still further object of this invention is the provision of a new casting apparatus and method wherein the mold itself consists of two or more movable portions which are slidable relative to one another so that the volume of the mold cavity does not change at any relative position of the mold portions.

Still a further object of this invention is the provision of a molding apparatus and method which permits the manufacture of multi-color molded articles or articles with integral molded designs. I

Briefly stated, in accordance with one embodiment of the invention, a mold is constructed from at least two portions so that at least one parting plane between any two portions coincides with the greatest cross-sectional area of the mold cavity compared to any other plane parallel to the parting plane; means are provided for sliding the mold portions with respect to one another so that a part of the cavity in one mold portion is exposed to form a filling orifice; a filling head is used to inject molten liquid detergent through the orifice until the entire cavity in the mold portions is completely full; the mold portions are then moved to a second position wherein the cavities in 3,034,177 Patented May '15, 1962 each portion are in alignment; the molten liquid detergent is permitted to solidify; the mold portions are then separated and the finished detergent bar is removed.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matterregarded as forming the present invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIGURE 1 is an elevation in cross-section of a mold and filling head in the filling position; and

FIGURE 2 is a view similar to FIGURE 1 showing the mold portions moved to the closed position so that the mold cavity is out of communication with the filling head; and

FIGURE 3 shows the mold portions in alignment while the cast detergent bar solidifies; and

FIGURE 4 shows the mold portions separated for removal of the finished bar; and

FIGURE 5 is a partial side elevation showing the mold parts in the depressed position as in FIGURE 1, and illustratin g the formation of the filling opening; and

FIGURES 6-10 are elevations, partly in cross-section, of a modified form of the invention which can beused for making multi-color detergent bars; and

FIGURE 11 is an elevation in cross-section of a mold for producing an integral ornamental design on a detergent bar; and

FIGURE 12 shows the sequence of steps followed by the apparatus of FIGURE 11 in producing a bar with an ornamental design; and i FIGURE 13 is a plan view of a detergent bar with'an integral ornamental design as can be made with the apparatus of FIGURE 11.

Referring now to the drawings and particularly to FIG- URES 14, there is shown a' mold generally indicated at 15 which is composed of the mold portions 16. and 17. Each of the portions 16 and 17 are hollowed as at 18 and 19 to form a cavity in the shape of the cast bar. Obvi ously of course, the hollowed out portions 18 and 19may take any shape and they need not be symmetrical. In the casting of objects such as detergent bars it is of course desirable that these hollowed portions be symmetrical when a typical oval shaped bar is being made. The parting plane 20 of the mold portions 16 and 17 is preferably made so that it coincides with the area of maximum cross section of the cast article compared to the area of crosssection through any other plane parallel to the parting plane 20. This, of course, is not only desirable but is necessary in order to remove the finished bar from the mold with a minimum of difiiculty in those cases where only two mold portions are used.

A filling head 21 having a filling passageway 22 is provided. The mold actuator 23 and the filling head 21 are used to slide the mold portions 16 and 17 as they move through the molding cycle.

While the operation of the invention in its various em-v bodiments is hereinafter described as applied to the molding ofdetergent bars, it will be understood that this is not to form a limitation on the scope of the invention as it may be applied to the casting of articles from any molten material. The use of the invention for casting detergent bars has been found to be of great utility and therefore it will be described in that context primarily for convenience. In operation, the filling head 21 slides the mold portion 16 with respect to mold portion 17 until a position substantially as shown in FIGURE 1 is reached. In this position, the passageway 22 is in communication with the filling orifice 24 shown in FIGURE 5. The area of the filling orifice 24 is comparatively large compared to the volume of the mold cavity. It will be noted that the filling orifice 24 will have an area bounded by the lower extremity of the hollow 19 and the bottom surface 25 of the mold portion 16. This relatively large opening is one of the important aspects of the invention as it permits relatively fast filling of the mold at low flow velocities. This has been found to substantially eliminate the dew line defects that are obtained in the casting of some materials with molding equipment in which high flow velocities or slow filling rates are employed.

In order to prevent an air lock in the upper portion of the mold and to facilitate filling of the cavity, it is preferred that the cavity be vented. It has been found that satisfactory venting can be achieved by merely separating the mold portions 16 and 17 by a very small amount, for example, a few thousandths of an inch. An opening of this magnitude will serve satisfactorily as a vent and yet it will not permit the molten detergent to escape as the injection pressures are relatively low, usually in the range of 1-20 p.s.i.g.

After the mold has been filled, the actuator 23 moves the portion 17 upwardly to close the orifice 24 as shown in FIGURE 2. The portion 17 is moved until it is in alignment with the portion 16. Then the filling head 21 and actuator 23 are Withdrawn as shown in FIGURE 3. The molten detergent material is permitted to stand in the mold until it has solidified sufiiciently to allow handling. To hasten solidification it will, of course, be evident that some kind of chilling or cooling means can be employed, generally taking the form of passageways for cooling fluid within the walls of the mold parts as will be fully understood by the Worker in the molding art. The specific nature of these chilling or cooling means does not, of course, form a limitation on the invention. After the bar has solidified, the mold portions 16 and 17 can be separated as shown in FIGURE 4 and the finished detergent bar removed.

FIGURES 6-10 show a modified form of the invention which can be used to make either a solid color detergent bar or it can be used to make a two color bar as will hereinafter be explained. Referring to the drawings, a mold 26 is shown which is composed of a mold portion 27 and a mold portion 28. The mold portion 27 is hollowed out asat 29 and the mold portion 28 is hollowed as at 30. A filling head 31 with a passageway 32 and an actuator 33 are also provided. It is necessary to employ a second filling head 34 having a passageway 35 and a second actuator 36 (FIGURES 8 and 9) when a twocolor detergent bar is to be cast.

When a two-color bar is to be made, the mold portions 27 and 28 are first positioned as shown in FIGURE 6 by means of the filling head 31. Molten detergent material of .one color is injected into the hollow 30 by the first filling head 31 through the passageway 32. When the hollow 30 has been filled, the mold portions 27 and 28 are moved by the actuator 33 to the position shown in FIGURE 7. The mold 26 is then rotated 180 and the mold portions 27 and 28 are moved by the second filling head 34 to the position shown in FIGURE 8. A molten detergent of a difierent color is then injected from the passageway 35 into the hollow 29. When the hollow 29 has been-filled, the second actuator 36 moves the mold portions 27 and 28 into the position shown in FIGURE 9. The second filling head 34 and actuator 36 are then withdrawn and the mold portions 27. and 28 moved to a position as shown in FIGURE wherein the hollows 29 and 30 are in alignment. This entire sequence is carried out in a reasonably short time interval so that the molten detergent injected into the hollows 29 and 30 does not solidify until the hollows 29 and 39 are aligned. After solidification, the two-color bar may be removed by separating the mold portions 27 and 28.

, It will be obvious, of course, that the apparatus described in FIGURES 6-10 is also capable of producing a single color bar although the mold shown in FIGURES 1-4 would -be more practical for that purpose. 7

FIGURES t1 and 12 illustrate another modification for producing a detergent bar having an ornamental design one one surface. For example, a bar 37 as shown in FIGURE 13 may be produced with a shamrock design 38 molded on one surface. The mold 39 shown in FIGURE 11 is composed of a mold portion 41), an ornamental design mold portion 41 and an intermediate mold portion 42. The mold portion 40 is hollowed as at 43 and the intermediate mold portion is hollowed as at 44. The ornamental design mold portion 41 has a hollow 45 which may be in the form of an ornamental design such as the shamrock 38 shown on the finished bar of FIG- URE 13. The mold 39 is provided with a first parting plane 46 between the mold portion 40 and the intermediate mold portion 42. A second parting plane 47 separates the ornamental design mold portion 41 and the intermediate mold portion 42. The purpose of the parting planes 46 and 4'7 will become evident when the manner of casting a bar with an ornamental design is described.

Referring now to FIGURE 12, the mold of FIGURE 11 is shown in position A wherein the ornamental design mold portion 41 has been moved along the second parting plane 47 in order to expose the hollows 43 and 44 to a filling head 48. When the cavity formed by the hollows 43 and 44 has been filled, the filling head 48 is withdrawn, the ornamental design mold portion 41 is moved on the parting plane 47 until hollows 43 and 44 are not exposed, and the mold rotated 180 to position B. In this position, a second filling head injects a'molten detergent material which may be of a different color into the hollow 45 at the opening shown by the arrow 49. The mold portions are then aligned into position C as shown in FIGURE 12. The mold portions are held in this position until the molten detergent materials have solidified. The mold is then separated along the first parting plane 46 as shown in position D in order to remove the finished bar. It will be evident that the first parting plane 46 is needed in order to make it possible to remove the finished bar. The first parting plane 46 coincides with the greatest crosssectional area of the finished bar compared to the area through any other plane parallel to the first parting plane. Obviously, of course, it would not be possible to remove the finished bar by separating the mold along the second parting plane 47. 7

It will be understood, of course, that in all of the preceding embodiments it is possible to provide a variety of means for sliding the mold portions with respect to each other. For instance, in the embodiment of FIG- URES l-4, the mold portion 16 can be held stationary and the actuator 23 can be provided with latching means for attachment to the mold portion 17. This would allow the actuator 23 to move the portion 17 through the entire cycle so that the filling head can be independently moved into position and withdrawn at the proper time in the cycle. Other actuating means will be evident to those skilled in the art. It is to be understood that the precise means for actuating the mold portions in each embodiment do not in any way limit the scope of this invention.

While particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention and it is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

What is claimed as new is:

1. Apparatus for casting molten material into an article of proper size and shape comprising a mold having a cavity and being formed from at least two mold portions having hollows which define said cavity, said mold portions being separated by a plane defined by surfaces extending from the hollows of the mold portions, said mold portions being slidable on said plane with respect to each other, a parting plane coinciding with the greatest cross-sectional area of the cavity compared to its cross-section through any other plane parallel to the parting plane, means for sliding the mold portions with respect to each other along the first mentioned plane to expose the cavity in at least one mold portion for filling, means including a filling head for injecting the cavity in each mold portion with molten material through any orifice created by exposing the cavity in at least one mold portion, all openings which would allow the molten material to escape the cavity being sealed by surfaces defining the first mentioned plane including extensions thereof, and means for sliding said mold portions back into alignment thereby permitting solidification of the article with the mold portions in alignment, the articles being removed upon separation of the mold portions.

2. Apparatus for molding solid articles from molten material comprising a mold, said mold being formed from at least two portions each of said portions being hollowed to form a part of the mold cavity, a parting plane between the two mold portions, means for sliding the mold portions on the parting plane to a filling position wherein the cavity of at least one mold portion is exposed to form a filling orifice of substantially large cross-section, a filling head for injecting molten material into said entire mold cavity formed in all the mold portions through said filling orifice, and a mold actuator for thereafter sliding said mold portions into alignment to permit the finished article to solidify, the finished article being removed upon separation of the mold at the area of greatest crosssection of the cavity.

3. Apparatus for casting articles from molten material comprising a mold having a cavity and being formed from at least two mold portions having hollows which define said cavity, said mold having a parting plane between said mold portions defined by surfaces extending from the hollows of the mold portions and coinciding with the greatest cross-sectional area of the cavity compared to the area of any other plane of cross-section parallel to the parting plane, means for sliding the mold portions with respect to each other along said parting plane to expose the cavity at least one mold portion for filling, means for filling the entire mold cavity with molten material through any orifice created by exposing the cavity, all openings which would allow the molten material to escape the cavity being sealed by surface defining said parting plane including extensions thereof, vent means in said mold for preventing an air lock, and means for sliding said mold portions with respect to each other into alignment to permit the molten material to solidify in proper form, the solid molded article being removed upon separation of said mold portions.

4. Apparatus for molding articles in two colors comprising a mold, said mold being formed from at least two portions, each of said portions having a cavity so that the parting plane between the two mold portions coincides with the area of greatest crosssection of the article formed by the entire mold cavity compared to the crosssectional area of any other plane parallel to the parting plane, means for sliding the mold portions to a first position wherein the cavities in each of the mold portions are not in communication so that a molten material of one color can be injected into one mold portion, means for sliding the mold portions to a second position wherein the cavities in the mold portions are not in communication so that a molten material of a different color can be injected into the other mold portion, at all times all openings being sealed which would allow the molten material to escape the cavities in the mold portions by surfaces defining said parting plane including extensions thereof, means for sliding the two mold portions with respect to each other into alignment before the molten material in each half solidifies whereby a two-color article is formed when the molten material in the mold cavity becomes solid.

5. Apparatus for molding an article with an ornamen- 6 7 p, tal design comprising a mold, said mold being composed of a first mold portion, an ornamental design mold portion having a hollow configured in an ornamental design and an intermediate mold portion interposed between the first mold portion and the ornamental design mold portion, a first parting plane defined by surfaces extending from the hollows of the mold portions between the first mold portion and the intermediate mold portion, said first parting plane coinciding with the area of greatest cross-section of the article being molded compared to the area of any other plane of cross-section parallel to the first parting plane, a second parting plane defined by surfaces extending from the hollows of the mold portions between the intermediate mold portion and the ornamental design mold portion, said second parting plane being at the plane of separation of the body of the article and the ornamental design, means for sliding the ornamental design mold portion along the second parting plane to a point where the hollow of the ornamental design portion is not in communication with the rest of the mold cavity, means for filling the first mold portion and the intermediate mold portion with molten material, means for filling the ornamental design mold portion with molten material, at all times all openings which would allow the molten material to escape from said portions being sealed by surfaces defining said planes including extensions thereof, means for sliding said mold portions with respect to each other into alignment to permit the molten material to solidify, the finished article being removed upon separation of the mold portions at the first parting plane.

6. A method for molding articles from molten material in a mold cavity formed by at least two mold portions having a parting plane coinciding with the area of greatestcross-section in the cavity when compared to the crosssectional area of the cavity taken through any other plane which is parallel to the parting plane, comprising the steps of displacing said mold portions along said parting plane so that the cavity of at least one mold portion is exposed for filling, injecting molten material into said entire cavity until full, sliding the mold portions into alignment and permitting the molten material to solidify into the finished article, thereafter separating the mold portions along the parting plane to remove the finished article.

7. A method for molding articles from molten material comprising the steps of injecting molten material into a mold formed from at least two portions and having a cavity with at least one parting plane coinciding with the area of greatest cross-section of the cavity when compared to the cross-sectional area of any other plane parallel to said parting plane, said injection step being carried out while the mold portions are out of alignment so that the cavity in at least one of the mold portions is exposed for filling, moving the mold portions into alignment after filling the cavity in each mold portion with molten material, allowing the molten material to solidify and thereafter separating the mold portions and removing the finished article.

8. Apparatus for molding a molten material into solid units of predetermined size and shape, comprising a mold composed of at least two mold portions, each of said mold portions having a hollow, said mold portions being movable while in contact with each other in the plane of contact from a position in which said hollows coincide to form a closed mold cavity to another position in which the hollow in at least one of said mold portions extends partially beyond an edge of the other of said mold portions so as to provide at least one opening for filling the hollow, means for filling said hollow through said opening, all openings which would allow material to escape from said hollows being sealed by surfaces defining the plane of contact including extensions thereof, means for moving said mold portions while in contact with each other so as to cause them to assume the stated positions alternately, and means for separating the mold portions after the molding operation in order to discharge a 5 molded article from the mold cavity.

References Cited in the file of this patent UNITED STATES PATENTS 2,510,841 Stowe June .6, 1950 2,637,073 Walther May 5, 1953 2,913,767 Simon Nov. 24, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent, No. 3.034 177 May 15, 1962 Leonard C. Hooper rtified that error appears in the above numbered pataid Letters Patent should read as It is hereby ee tion and that the 5 ant requiring eorrec corrected below.

line 39, after -"cavity" insert in Column 5,

this 11th day of September 1962.

Signed and sealed (SEAL) Attest:

ERNEST w. SWIDER DAVID L- LA D Commissioner of Patents Attesting Officer

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