Precision glass pressing mold and method of molding glass

Claim 2

In a system for precision pressing of glass articles wherein a primary plunger is stroked to press glass in a mold, the improvement which comprises: a mold body member having an article defining cavity formed therein, said cavity being open at its upper end to receive a molten glass charge and communicating with an opening through the lower portion of said body member, said body member being formed with a plurality of vacuum slots communicating with said cavity and with a vacuum channel, radially, outwardly displaced from said cavity communicating with said vacuum slots; movable means positioned in said opening; means connected to said movable means for powering said movable means for applying a secondary pressing stroke to a glass charge contained in said cavity; and control means responsive to the completion of the primary plunger pressing stroke, and connected to said means for powering said movable means, for initiating said secondary stroke.

Claim 3

In a system for precision pressing of glass articles, wherein a primary plunger is stroked to press glass in a mold, the improvement which comprises: a mold body member having an article defining cavity formed therein, said cavity being open at its upper end to receive a molten glass charge and communicating with an opening through the lower portion of said body member; a pressing piston positioned in said opening; a connecting rod attached to said pressing piston; a pivotally mounted operating lever attached at one end to said connecting rod; a secondary pressing cylinder; means connecting said secondary pressing cylinder to the end of said operating lever opposite said connecting rod; a source of air under pressure connected to said secondary pressing cylinder; a solenoid valve connected intermediate said secondary pressing cylinder and said source of air under pressure; a switch electrically connected to said solenoid valve to open the valve to allow a flow of air to said secondary pressing cylinder when said switch is activated; and an actuating arm carried by said primary pressing plunger for actuating said switch when said primary plunger completes its pressing stroke, thereby causing said pressing piston to apply a secondary pressing stroke to a glass charge contained in said cavity in response to the completion of the primary plunger pressing stroke.

Claim 4

In a system for precision pressing of glass articles, wherein a primary plunger is stroked to press glass in a mold, the improvement which comprises: a mold body member having an article defining cavity formed therein, said cavity being open at its upper end to receive a molten glass charge and communicating with an opening through the lower portion of said body member; a pressing piston positioned in said opening; a connecting rod attached to said pressing piston; a pivotally mounted operating lever attached at one end to said connecting rod; a secondary pressing cylinder; means connecting said secondary pressing cylinder to the end of said operating lever opposite said connecting rod; a source of air under pressure connected to said secondary pressing cylinder; a solenoid valve connected intermediate said secondary pressing cylinder and said source of air under pressure; a switch electrically connected to said solenoid valve to open the valve to allow a flow of air to said secondary pressing cylinder when said switch is activated; and an actuating arm carried by said primary pressing plunger for actuating said switch when said primary plunger completes its pressing stroke, thereby causing said pressing piston to apply a secondary pressing stroke to a glass charge contained in said cavity in response to the completion of the primary plunger pressing stroke.

Claim 5

Apparatus for precision pressing of glass articles from charges of molten glass delivered thereto comprising, in combination: reciprocal power means for developing a primary pressing pressure; a primary glass pressing plunger carried by said power means for imparting a primary pressing stroke to said glass charges; a mold for receiving said glass charges, said mold comprising a body member having an article defining cavity formed therein, said cavity being open at its upper end to receive said glass charges and communicating with an opening through the lower portion of said body member, said body member being formed with a plurality of vacuum slots communicating with said cavity and with a vacuum channel, radially, outwardly displaced from said cavity, formed in said body member and communicating with said vacuum slots; movable means positioned in said opening for applying a secondary pressing stroke to said glass charges contained in said cavity; means connected to said movable means for powering said movable means; and control means, responsive to the completion of said primary pressing stroke, connected to said means for powering said movable means for initiating said secondary strOke.

Claim 6

Apparatus for precision pressing of glass articles from charges of molten glass delivered thereto comprising, in combination: reciprocal power means for developing a primary pressing pressure; a primary glass pressing plunger carried by said power means for imparting a primary pressing stroke to said glass charges; a mold for receiving said glass charges, said mold comprising a body member having an article defining cavity formed therein, said cavity being open at its upper end to receive said glass charges and communicating with an opening through the lower portion of said body member, said body member being formed with a plurality of vacuum slots communicating with said cavity and with a vacuum channel, radially, outwardly displaced from said cavity, formed in said body member and communicating with said vacuum slots; movable means positioned in said opening for applying a secondary pressing stroke to said glass charges contained in said cavity; means connected to said movable means for powering said movable means; and control means, responsive to the completion of said primary pressing stroke, connected to said means for powering said movable means for initiating said secondary strOke.

Claim 7

Apparatus for precision pressing of glass articles from charges of molten glass delivered thereto comprising, in combination: reciprocal power means for developing a primary pressing pressure; a primary glass pressing plunger carried by said power means for imparting a primary pressing stroke to said glass charges; a mold for receiving said glass charges, said mold comprising a body member having an article defining cavity formed therein, said cavity being open at its upper end to receive said glass charges and communicating with an opening through the lower portion of said body member; a movable pressing piston positioned in said opening for applying a secondary pressing stroke to said glass charges contained in said cavity; a connecting rod attached to said pressing piston; a pivotally mounted operating lever attached at one end to said connecting rod; a secondary pressing cylinder; means connecting said secondary pressing cylinder to the end of said operating lever opposite said connecting rod; a source of air under pressure connected to said secondary pressing cylinder; a solenoid valve connected intermediate said secondary pressing cylinder and said source of air under pressure; a switch, electrically connected to said solenoid valve to open the valve to allow a flow of air to said secondary pressing cylinder when said switch is actuated; and, an actuating arm carried by said primary pressing plunger for actuating said switch when said primary plunger completes its pressing stroke.

Claim 8

Apparatus for precision pressing of glass articles from charges of molten glass delivered thereto comprising, in combination: reciprocal power means for developing a primary pressing pressure; a primary glass pressing plunger carried by said power means for imparting a primary pressing stroke to said glass charges; a mold for receiving said glass charges, said mold comprising a body member having an article defining cavity formed therein, said cavity being open at its upper end to receive said glass charges and communicating with an opening through the lower portion of said body member; a movable pressing piston positioned in said opening for applying a secondary pressing stroke to said glass charges contained in said cavity; a connecting rod attached to said pressing piston; a pivotally mounted operating lever attached at one end to said connecting rod; a secondary pressing cylinder; means connecting said secondary pressing cylinder to the end of said operating lever opposite said connecting rod; a source of air under pressure connected to said secondary pressing cylinder; a solenoid valve connected intermediate said secondary pressing cylinder and said source of air under pressure; a switch, electrically connected to said solenoid valve to open the valve to allow a flow of air to said secondary pressing cylinder when said switch is actuated; and, an actuating arm carried by said primary pressing plunger for actuating said switch when said primary plunger completes its pressing stroke.

Claim 9

In the method of forming glass articles of precise dimensions, wherein a molten glass charge containing glass in excess of that required to form said article is delivered into an open-topped mold whose cavity has the precise external configuration of the article to be formed, the steps of: moving a primary plunger having the precise internal dimensions of the article to be formed into said charge of glass; finally positioning said primary plunger in a precise location relative to the cavity in said mold; simultaneously with the movement of said primary plunger to its final position, closing the open top of said mold at a precise elevation; flowing the excess volume of glass into an opening communicating with said cavity; forcing a portion of said excess volume of glass, in response to the closing of the open top of said mold, back into said cavity through said opening to thereby completely fill said cavity; and applying a vacuum to said cavity for partially pulling said glass charge into conformity with said cavity.

Claim 10

In the method of forming glass articles of precise dimensions, wherein a molten glass charge containing glass in excess of that required to form said article is delivered into an open-topped mold whose cavity has the precise external configuration of the article to be formed, the steps of: moving a primary plunger having the precise internal dimensions of the article to be formed into said charge of glass; finally positioning said primary plunger in a precise location relative to the cavity in said mold; simultaneously with the movement of said primary plunger to its final position, closing the open top of said mold at a precise elevation; flowing the excess volume of glass into an opening communicating with said cavity; forcing a portion of said excess volume of glass, in response to the closing of the open top of said mold, back into said cavity through said opening to thereby completely fill said cavity; and applying a vacuum to said cavity for partially pulling said glass charge into conformity with said cavity.

Claim 11

The apparatus of claim 1, wherein said movable means comprises a pressing piston.

Claim 12

The apparatus of claim 6, wherein said means for powering said piston comprises, in combination: a connecting rod attached to said pressing piston; a pivotally mounted operating lever attached at one end to said connecting rod; a secondary pressing cylinder; means connecting said secondary pressing cylinder to the end of said operating lever opposite said connecting rod; and a source of air under pressure connected to said secondary pressing cylinder.

Claim 13

The apparatus of claim 7, wherein said control means comprises, in combination: a solenoid valve connected intermediate said secondary pressing cylinder and said source of air under pressure; a switch electrically connected to said solenoid valve to open the valve to allow a flow of air to said secondary pressing cylinder when said switch is actuated; and an actuating arm carried by a primary pressing plunger for actuating said switch when said primary plunger completes its pressing stroke.

Claim 14

The apparatus of claim 2, wherein said body member is formed with a plurality of vacuum slots communicating with said cavity, and a vacuum channel, radially, outwardly displaced from said cavity, formed in said body member and communicating with said vacuum slots.

Claim 15

The apparatus of claim 3, wherein said movable means comprises a pressing piston.

Claim 16

The apparatUs of claim 10, wherein said means for powering said pressing piston comprises, in combination: a connecting rod attached to said pressing piston; a pivotally mounted operating lever attached at one end to said connecting rod; a secondary pressing cylinder; means connecting said secondary pressing cylinder to the end of said operating lever opposite said connecting rod; and, a source of air under pressure connected to said secondary pressing cylinder.

Claim 17

The apparatus of claim 11, wherein said control means comprises, in combination: a solenoid valve connected intermediate said secondary pressing cylinder and said source of air under pressure; a switch, electrically connected to said solenoid valve to open the valve to allow a flow of air to said secondary pressing cylinder when said switch is actuated; and, an actuating arm carried by said primary pressing plunger for actuating said switch when said primary plunger completes its pressing stroke.

Claim 18

The apparatus of claim 4, wherein said body member is formed with a plurality of vacuum slots communicating with said cavity, and a vacuum channel, radially, outwardly displaced from said cavity, formed in said body member and communicating with said vacuum slots.

Claim 19

The method of claim 5, further including the steps of: removing said primary plunger from said cavity; removing said formed article from said cavity; and removing the remaining excess volume of glass from said article.