Precision molding apparatus

Claim 2

Mold apparatus for precision molding tubular elastomeric articles from an extrudable elastomer material comprising, in combination, a male mold including an elongated male member having a longitudinal bore therethrough substantially centrally thereof terminating in an annular end portion and a plunger reciprocable within said bore, a female mold member having an elongated recess therein having a base portion including an annular seat portion therein adapted to receive said male member in spaced relation thereto to form an annular mold cavity therebetween having a first end at said base and an opposite end, each of said mold members having transverse and longitudinal precision alignment surfaces adapted to mate and to accurately space said male member from said recess to thereby accurately define said mold cavity, means for supporting said mold members sequentially and intermittently in (1) an open position (2) a cavity fill position wherein said transverse alignment surfaces are in spaced Relation and said longitudinal alignment surfaces are in contact, said annular end of said male mold is held in close proximity to said seat to form an annular orifice at said first end of said cavity and an annular opening is formed at the opposite end thereof, and (3) a mold close position wherein said transverse alignment surfaces are tightly engaged and said orifice and said opening are restricted, said plunger means being operative to force said extrudable elastomer into said cavity through said orifice while the molds are in said cavity fill position and to cause said material to freely and completely fill said mold cavity, and said mold cavity surfaces being operative to exert uniform pressure on said elastomeric material in said mold close position while said material is being cured.

Claim 3

Mold apparatus for precision molding tubular elastomeric articles from an extrudable elastomer material comprising, in combination, a male mold including an elongated male member having a longitudinal bore therethrough substantially centrally thereof terminating in an annular end position and a plunger reciprocable within said bore, a female mold member having an elongated recess therein having a base portion including an annular seat portion therein adapted to receive said male member in spaced relation thereto to form an annular mold cavity therebetween having a first end at said base and an opposite end, each of said mold members having frustoconical precision alignment surfaces accurately concentric to the longitudinal axis of the apparatus and precision transverse alignment surface adapted to mate and to accurately space said male member from said recess to thereby accurately define said mold cavity, means for supporting said mold members sequentially and intermittently in (1) an open position (2) a cavity fill position wherein said transverse alignment surfaces are spaced about 0.020 inch apart and said frustoconical alignment surfaces are in contact, said annular end of said male mold is held within about 0.020 inch of said seat to form an annular orifice at said first end of said cavity and an annular opening of about 0.020 inch is formed at the opposite end thereof, and (3) a mold close position wherein said transverse alignment surfaces are tightly engaged and said orifice and said opening are restricted, said plunger means being operative to force said extrudable elastomer into said cavity through said orifice while the molds are in said cavity fill position and to cause said material to freely and completely fill said mold cavity, and said mold cavity surfaces being operative to exert uniform pressure on said elastomeric material in said mold close position while said material is being cured.

Claim 4

Mold apparatus for precision molding tubular elastomeric articles from an extrudable elastomer material comprising, in combination, a male mold including an elongated male member having a longitudinal bore therethrough substantially centrally thereof terminating in an annular end position and a plunger reciprocable within said bore, a female mold member having an elongated recess therein having a base portion including an annular seat portion therein adapted to receive said male member in spaced relation thereto to form an annular mold cavity therebetween having a first end at said base and an opposite end, each of said mold members having frustoconical precision alignment surfaces accurately concentric to the longitudinal axis of the apparatus and precision transverse alignment surface adapted to mate and to accurately space said male member from said recess to thereby accurately define said mold cavity, means for supporting said mold members sequentially and intermittently in (1) an open position (2) a cavity fill position wherein said transverse alignment surfaces are spaced about 0.020 inch apart and said frustoconical alignment surfaces are in contact, said annular end of said male mold is held within about 0.020 inch of said seat to form an annular orifice at said first end of said cavity and an annular opening of about 0.020 inch is formed at the opposite end thereof, and (3) a mold close position wherein said transverse alignment surfaces are tightly engaged and said orifice and said opening are restricted, said plunger means being operative to force said extrudable elastomer into said cavity through said orifice while the molds are in said cavity fill position and to cause said material to freely and completely fill said mold cavity, and said mold cavity surfaces being operative to exert uniform pressure on said elastomeric material in said mold close position while said material is being cured.

Claim 5

Mold apparatus for precision molding tubular elastomer articles from an extrudable elastomer material comprising, in combination, a movable male mold including an elongated male member having a longitudinal bore therethrough substantially centrally thereof terminating in an annular end portion and a plunger reciprocable within said bore, a female mold attached to a stationary platen having an elongated recess therein having a base portion including an annular seat portion therein adapted to receive said male member in spaced relation thereto to form an annular mold cavity therebetween having a first end at said base and an opposite end, each of said mold members having frustoconical precision alignment surfaces accurately concentric to the longitudinal axis of the apparatus and precision transverse alignment surfaces adapted to mate and to accurately space said male member from said recess to thereby accurately define said mold cavity, means for supporting said mold members sequentially, in (1) an open position, (2) a cavity fill position wherein said transverse alignment surfaces are in spaced relation and said frustoconical alignment surfaces are in contaCt, said annular end of said male mold is held in close proximity to said seat to form an annular orifice at said first end of said cavity and an annular opening is formed at the opposite end thereof, and (3) a mold close position wherein said transverse alignment surfaces are tightly engaged and said orifice and said opening are restricted, said means for supporting said mold members including a vertically movable annular sleeve surrounding said male and female molds, said male mold being freely movable within said sleeve, a split spacer ring insertable between said sleeve and said platen in said cavity fill position whereby said sleeve is moved upward and caused to protrude above said male member, and a press longitudinally movable above said sleeve and male mold adapted to engage said sleeve when said ring is inserted between said sleeve and said platen in said cavity fill position and to apply pressure to said male mold when said ring is removed, said plunger means being operative to force said extrudable elastomer into said cavity through said orifice when said molds are in said cavity fill position with said ring inserted between said sleeve and said press is in engagement with said sleeve to limit the upward movement of said male mold to thereby limit the maximum thickness of said orifice, and said press being operative to force said molds to said mold closed position when said mold cavity is filled and said ring is removed to exert uniform pressure on said elastomeric material in said cavity while said material is being cured.

Claim 6

Mold apparatus for precision molding tubular elastomer articles from an extrudable elastomer material comprising, in combination, a movable male mold including an elongated male member having a longitudinal bore therethrough substantially centrally thereof terminating in an annular end portion and a plunger reciprocable within said bore, a female mold attached to a stationary platen having an elongated recess therein having a base portion including an annular seat portion therein adapted to receive said male member in spaced relation thereto to form an annular mold cavity therebetween having a first end at said base and an opposite end, each of said mold members having frustoconical precision alignment surfaces accurately concentric to the longitudinal axis of the apparatus and precision transverse alignment surfaces adapted to mate and to accurately space said male member from said recess to thereby accurately define said mold cavity, means for supporting said mold members sequentially, in (1) an open position, (2) a cavity fill position wherein said transverse alignment surfaces are in spaced relation and said frustoconical alignment surfaces are in contaCt, said annular end of said male mold is held in close proximity to said seat to form an annular orifice at said first end of said cavity and an annular opening is formed at the opposite end thereof, and (3) a mold close position wherein said transverse alignment surfaces are tightly engaged and said orifice and said opening are restricted, said means for supporting said mold members including a vertically movable annular sleeve surrounding said male and female molds, said male mold being freely movable within said sleeve, a split spacer ring insertable between said sleeve and said platen in said cavity fill position whereby said sleeve is moved upward and caused to protrude above said male member, and a press longitudinally movable above said sleeve and male mold adapted to engage said sleeve when said ring is inserted between said sleeve and said platen in said cavity fill position and to apply pressure to said male mold when said ring is removed, said plunger means being operative to force said extrudable elastomer into said cavity through said orifice when said molds are in said cavity fill position with said ring inserted between said sleeve and said press is in engagement with said sleeve to limit the upward movement of said male mold to thereby limit the maximum thickness of said orifice, and said press being operative to force said molds to said mold closed position when said mold cavity is filled and said ring is removed to exert uniform pressure on said elastomeric material in said cavity while said material is being cured.

Claim 7

Apparatus of claim 3 wherein the maximum thickness of said orifice is about 0.020 inch.

Claim 8

Apparatus of claim 3 wherein the dimensions of said female mold frustoconical surfaces are slightly smaller than the corresponding male frustoconical surfaces whereby said male member annular end portion is slightly spaced from said annular seat portion in said cavity fill position and said press is operative to force said frustoconical surfaces and said transverse surfaces into a mating relation in said mold closed position.