Apparatus for molding two-tone colored plastic shells

Claim 1

Apparatus for molding a two tone colored, thin walled plastic shell including a heated mold and a powder charge box connected to the heated mold and seal means between said powder charge box and said heated mold to define a first powder casting surface on said heated mold for forming a shell of one color and to define a second powder casting surface on said heated mold forming a shell of another color comprising: a divider wall and a perimeter wall on said powder charge box for separating said powder charge box into first and second chambers; said divider wall having a horizontal surface and a vertical end surface on either end of said horizontal surface; said heated mold having a perimeter wall generally congruent with said perimeter wall of said powder charge box; said perimeter wall of said heated mold horizontally spaced from each of said vertical end surfaces to form a gap therebetween; said heated mold further having a rib with a horizontal surface raised above the first and second powder casting surfaces, said horizontal surface located a fixed vertical distance from said horizontal surface of said divider wall; a first seal member carried on said divider wall having a base segment secured to said horizontal and vertical end surfaces of said divider wall; a sealing bead surface on said first seal member having a first seal bead portion extending across the full length of said horizontal surface and having second and third seal bead portions extending across the full lengths of said vertical end surfaces; and a hollow, yieldable core on said first seal member connected to said base segment and to said sealing bead surface; said yieldable core expandable vertically to cause said first seal bead portion to bridge the fixed vertical distance between said horizontal surface on said rib and said horizontal surface of said divider wall to seal therebetween; said yieldable core expandable horizontally to cause said second and third seal bead portions to bridge the gap between the vertical end surfaces of said divider wall and said heated mold to seal therebetween; a second seal member carried on said perimeter wall of said powder charge box; said second seal member having a hollow core compressible against said perimeter wall of said heated mold when the powder box is connected to said heated mold; said hollow yieldable core of said first seal member having a vertically flattened position with a width greater than the width of said horizontal surface of said rib when deflated and a vertically expanded position when inflated with a width which is substantially the same as the width of said horizontal surface of said rib; means for selectively inflating and deflating said hollow yieldable core of said first seal member from its vertically flattened position to said vertically expanded position and operative when the powder charge box is connected to said heated mold to cause said first seal member to inflate so as to cause said sealing bead surface to fully cover said horizontal surface of said rib without horizontally overlying the powder casting surfaces; said means for selectively inflating and deflating said hollow yieldable core of said first seal member operative to deflate said hollow yieldable core to cause it to retract to its vertically flattened position while said second seal member expands following separation of said powder charge box and said heated mold upon formation of separated two tone color segments on said first and second casting surfaces so as to expose said horizontal surface of said rib for application of additional material thereagainst to form a connector bond between first and second color segments.