Application of Venner

• Decision Date: 19 December 1958
• Docket Number: Patent Appeal No. 6391.
• Parties: Application of William M. VENNER and Percy L. Bowser, Jr.
• Court: U.S. Court of Customs and Patent Appeals (CCPA)

120 USPQ 193, 262 F.2d 91 (1958)

Application of William M. VENNER and Percy L. Bowser, Jr.

Patent Appeal No. 6391.

United States Court of Customs and Patent Appeals.

December 19, 1958.

John H. Bruninga, St. Louis, Mo., and Richard G. Radue, Washington, D. C., for appellants.

Clarence W. Moore, Washington, D. C. (George C. Roeming, Washington, D. C., of counsel), for the Commissioner of Patents.

Before O'CONNELL, Acting Chief Judge, and WORLEY, RICH, and MARTIN, Judges.

MARTIN, Judge.

This is an appeal from the decision of the Board of Appeals of the Patent Office affirming the final rejection by the examiner of claims 1, 2, 5, 8, 10, 13 and 20, all of the claims remaining, of application serial No. 309,966, for "Apparatus for Molding Trunk Pistons." The subject matter of the claims on appeal was disclosed in a parent application of the same inventors, serial No. 789,124, filed December 1, 1947, and co-pending with the instant application.

The appealed claims relate to a permanent mold casting apparatus for molding trunk pistons of aluminum and magnesium alloys wherein the mold comprises two external horizontally movable outer mold sections, a pair of internal horizontally displaceable side core sections which form the interior surfaces of the piston, and a vertically acting middle core section withdrawable from between the side core sections so as to permit the latter to collapse towards one another, thereby releasing the molded solidified piston. The outer mold sections in assembled position form a gate into which the molten metal may be fed by gravity to fill the mold cavity. The middle core section is positioned by a piston type fluid motor which withdraws the said section when actuated. The alleged invention resides in the provision of "time-controlled means" to actuate the said fluid motor in order to withdraw the middle core section at the proper time after pouring the metal into the mold so as to prevent slumping of the metal or excessive contraction thereof on the core members. The "time-controlled means" are initiated by the molder by depressing a foot-operated switch immediately after pouring the molten metal into the gate.

Claim 1, which is regarded as representative of the claims on appeal, reads as follows:

"1. An apparatus for molding trunk pistons of aluminum and magnesium alloys having relatively high crystallization shrinkages and coefficients of thermal expansion, such piston embodying a head having a relatively thick cross-section and a cylindrical skirt of relatively thin cross-section provided with inwardly extending wrist pin bosses of relatively thick cross-section, comprising, a pair of separable mold sections shaped to the outside of the piston and provided with a gate at the top adapted to cast the piston with the head up, a sectional core shaped to the inside of the piston and embodying a middle section movable downwardly between and below side sections which are shaped to form the bosses and are freely movable laterally into the space when vacated by said middle section, power-operated means connected to move said middle section downwardly below said side sections, time-controlled means set to the period between the completion of the pouring of the metal in the mold and solidification of the metal of the piston therein, means controlled by said time-controlled means and controlling said power-operated means in order to move said middle section downwardly at the end of said period to release it from the casting and to permit the side sections to freely move laterally away from the casting, and means accessible to the molder when pouring for initiating the starting of said time-controlled means after the completion of such pouring."

The references relied on are:

                  Nichols          1,925,496   Sept. 5, 1933
                  Stern            2,145,956   Feb.  7, 1939
                  Wagner           2,190,496   Feb. 13, 1940
                  Flammang et al.  2,204,407   June 11, 1940
                  Waldie           2,363,759   Nov. 28, 1944
                  Venner et al.    2,588,898   Mar. 11, 1952
                

Venner et al., a patent issued to the same inventors as those herein, was copending with appellants' parent application. The said patent discloses a permanent molding apparatus for aluminum alloy trunk pistons comprising exterior mold sections, side core parts, and a power operated central core part, which parts are said to "be of any suitable construction as shown in the various patents enumerated above." The admitted prior art disclosure included the Flammang et al. patent, discussed, infra. The claims of the Venner et al. patent set forth a multiple mold apparatus supported on a rotatable carrier, which is actuated by power operated means at the disposal of the molder to position the carrier and the molds together with their respective core sections for the alternate pouring and solidification steps.

The Flammang et al. reference relates to a trunk piston permanent molding machine of the same general class as applicants' including a pair of mold sections, two side core sections, and a center core section capable of being vertically withdrawn to permit inward movement of the side core sections and removal of the formed casting. Flammang et al. teach freeing the casting from the side core sections "as soon as the operator is satisfied that the casting has cooled to a sufficient state of hardness."

Stern discloses a die casting machine wherein molten metal is injected into the die cavity and a timer controls the operation of an ejector pin which pin ejects the casting from the die subsequent to the formation thereof and in timed sequence therewith.

The Waldie patent discloses a die casting machine for aluminum and other metals in which a timer is actuated to open the die and discharge the casting therefrom. No core is removed from the die; instead, the die members are merely separated from one another.

The Nichols reference discloses a permanent molding apparatus for the manufacture of castings from metal, such as cast iron. The core is retracted automatically from the mold "after the castings have solidified around the cores and before the castings begin to contract." The said mold is mounted on a rotatable carrier which moves intermittently to position each mold successively for pouring of the molten metal, core withdrawal, and ejection of the finished casting. The said patent discloses that:

"* * * the amount of time which should elapse between the filling of the mold and the withdrawing of the cores depends upon the time required for chilling that portion of the casting adjacent the core sufficiently to solidify it. As this time is variable depending on the size of the casting and the material used it is necessary to vary the time required to pass between the stations. * * *"

The Wagner patent shows a permanent molding apparatus for manufacturing engine blocks in which a plurality of core members are withdrawn from the mold automatically upon closing an electrical circuit.

The rejection of claims 1, 2, and 5 as "lacking invention over Venner et al. in view of either Stern or Waldie, when viewed in the light of the art as evidenced by Wagner and Nichols," was affirmed by the Board of Appeals. The basic features of these claims are found in claim 1 and the differences therefrom recited in the other enumerated claims do not patently distinguish over the reference combination cited; accordingly, the...