Kenneth B Robb

US Patent:

48406562, Jun 20, 1989

Filed:

Oct 17, 1988

Appl. No.:

7/259465

Inventors:

Michael J. Ziegler - Parma OH
Barry Millward - Chagrin Falls OH
Kenneth P. Robb - Stow OH

Assignee:

AGA A.B. - Lidingo

International Classification:

C03B 936

US Classification:

65 85

Abstract:

A system for forming hollow pressed glass articles utilizes a flow of cryogen that is mixed with air to provide a cooling gas that enables newly pressed articles to be removed from their molds after a thin skin of solidified glass has been formed on internal surfaces of the articles to strengthen the newly formed articles and to give them shape stability. Two flows of cryogen are used, one being a gentle, substantially continuous flow of cryogen gas from a low pressure source, the other being a controlled intermittent flow of cryogen vapor in liquid and/or gaseous form from a high pressure source. To assure a proper introduction of cryogen vapor, and to prevent debilitating accumulations of ice within and about the tube that is used to inject high pressure cryogen, the high pressure injector tube is surrounded by a low pressure cryogen flow tube, through which a flow of low pressure cryogen gas is maintained on a substantially continuous basis. By this arrangement, when the high pressure flow of cryogen is shut off between bursts of flow into mold cavities that are brought sequentially into a cooling gas injection station, the discharge end of the high pressure injector tube is kept purged of moisture laden ambient air. Because the system of the present invention hastens cooling and solidification of newly formed glass articles, the time during which the articles must be retained in their molds is significantly reduced.