Method of forming a vial blowback cavity

A method of forming a mouth adjacent cavity in a cylindrical article, comprising the steps of:

• providing cylindrical stock having a flared end adjacent region and a reduced diameter region adjacent said flared region,
• rotating said cylindrical stock,
• applying heat to said flared region and said reduced diameter region of said cylindrical stock,
• forming an enlarged diameter region adjacent said reduced diameter region and an axially extending terminal lip by inserting a stepped mandrel into said flared region and said reduced diameter region and applying a first external die to said flared and said reduced diameter regions,
• applying heat to said axially extending terminal lip, and
• rolling said axially extending terminal lip inwardly by inserting a mandrel generally into said enlarged diameter portion and applying a second external die to said lip.

A method of forming a mouth adjacent cavity in a cylindrical article, comprising the steps of:

• providing cylindrical stock having a flared end adjacent region and a reduced diameter region adjacent said flared region,
• rotating said cylindrical stock,
• applying heat to said flared region and said reduced diameter region of said cylindrical stock,
• forming an enlarged diameter region adjacent said reduced diameter region and an axially extending terminal lip by substantially simultaneously inserting a stepped mandrel into said flared region and said reduced diameter region and applying a first external die to said flared and said reduced diameter regions,
• applying heat to said axially extending terminal lip, and
• rolling said axially extending terminal lip inwardly by substantially simultaneously inserting a mandrel generally into said enlarged diameter portion and applying a second external die to said lip.

A method of forming a mouth adjacent cavity in a cylindrical glass article comprising the steps of:

• providing a cylindrical glass stock having a reduced diameter region adjacent one end of such cylindrical stock, and rotating such cylindrical stock;
• applying heat to such one end and such reduced diameter region of such cylindrical stock;
• forming an axially extending terminal lip with excess glass at the one end of the stock;
• applying heat to the axially extending terminal lip;
• and
• rolling such axially extending terminal lip with excess glass axially inwardly by rotating the heated lip over an external die with a solid die surface that forces the heated glass inwardly to provide a blowback cavity at the end of the stock.

A method of forming a mouth adjacent cavity in a cylindrical glass tube stock, the stock being continuously moved in a generally horizontal plane as part of a line of a plurality of tube stocks, the method comprising the steps of:

• applying heat to one end of the stock having a reduced diameter region;
• heating the end of the stock while continuing to rotate the stock;
• forming at the reduced end of the stock an axially extending terminal lip with excess glass by rotating the heated end over a first external die and simultaneously inserting a first translating mouth plug into the mouth of the stock;
• applying heat to the terminal lip;
• and
• rolling the terminal lip inwardly axially by rotating the lip against a solid die surface of a fixed second external die and simultaneously inserting a second translating mouth plug into the mouth of the stock to form a glass vial with a blowback cavity.

A method of forming a mouth adjacent cavity in a hollow glass tube stock having a reduced diameter end, a plurality of the stocks being continuously transported in a generally horizontal plane and each stock being rotated, the method comprising the steps of:

• applying a stepped mandrel internally of a heated end portion of the stock adjacent to a reduced diameter to expand the tubular end portion in forming an axially extending terminal lip with excess glass by rotating the stock over the stepped mandrel;
• heating the terminal lip portion;
• and
• rolling the heated lip portion axially inwardly by rotating the heated end lip over an external die having a die surface that forces the heated glass inwardly to form a partially closed blowback cavity on the end of the tubular article.