The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 2015
Filed:
Oct. 18, 2013
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
Makoto Yoshida, Ibaraki, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
A porous preform production apparatus having a reaction vessel which includes an upper deposition chamber having an air supply inlet and an exhaust outlet, a lower deposition chamber having an air supply inlet, and a top chamber disposed on top of the upper deposition chamber and adapted to lift and store a porous preform formed by deposition, characterized in that the floor of the upper deposition chamber is disposed at a height between the lower end of a straight body part and the deposition tip of the porous glass preform during deposition, and a connection opening which connects the upper deposition chamber with the lower deposition chamber, is provided on the floor of the upper deposition chamber, and that when the aperture diameter of the connection opening is designated as A and the diameter of the porous preform passing through the connection opening as B, the ratio B/A satisfies the expression 0.05≦B/A≦0.6.