Glass manufacturing – With apparatus safety means
Reexamination Certificate
2000-09-08
2001-11-13
Vincent, Sean (Department: 1731)
Glass manufacturing
With apparatus safety means
C065S170000, C065S325000, C065S331000, C065S355000
Reexamination Certificate
active
06314761
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a feeder tube assembly for a feeder bowl of a glass melting furnace forehearth. More particularly, this invention relates to a lift mechanism for adjustably supporting a forehearth feeder tube during its operation, and for lifting the feeder tube from its operating position during the removal of the feeder tube for replacement of the feeder tube or replacement of the feeder bowl.
BACKGROUND OF THE INVENTION
U.S. Pat. 5,718,741 (Hull et al.), which is assigned to the assignee of this application, the disclosure of which is incorporated herein by reference, discloses a forehearth for cooling a stream of molten glass as it flows from a glass melting furnace to a forming machine for forming the molten glass into finished products, for example, hollow glass containers of the type widely used in packaging various food, beverage and other products. In the arrangement of the '741 Patent, and in a variety of other types of forehearths, molten glass flows downwardly through an opening, or a plurality of openings, in the bottom of a feeder bowl at an end of the forehearth that is remote from the end into which molten glass from the melting furnace flows.
To control the flow of molten glass from a forehearth feeder bowl, a vertically extending, refractory feeder tube is provided with its lowermost end immersed in the feeder bowl to a level slightly above the inside surface of the bottom of the feeder bowl and surrounding the opening(s) at the bottom of the feeder bowl, and the ceramic tube is caused to rotate slowly during the operation of the forehearth to ensure a proper mixing and temperature uniformity of the molten glass flowing from the feeder bowl. A feeder bowl refractory tube with a tube drive system of this general type is disclosed in U.S. Pat. No. 5,660,610 (DiFrank), which is also assigned to the assignee of this application, the disclosure of which is also incorporated by reference herein. Other glass forehearth feeder bowl feeder tube arrangements are described in U.S. Pat. No. 5,693,114 (Scott), U.S. Pat. No. 4,514,209 (Mumford) and U.S. Pat. No. 4,478,631 (Mumford), the disclosure of each of which is also incorporated by reference herein.
From time to time during the operation of a glass manufacturing system of a type employing a forehearth feeder bowl feeder tube of the type described above it is necessary to remove the feeder tube and/or the feeder bowl for repair or replacement. In the case of the replacement of the feeder bowl, the feeder tube must also be swung horizontally out of the way of the feeder bowl as well as being lifted vertically so that its lower edge clears the upper extent of the feeder bowl. It is also necessary from time to time to be able to adjust the height of the feeder tube. As a feeder tube of this type is quite massive, very large forces are required to lift it from its operating position. Heretofore, counterweighted lift mechanisms were employed for this purpose, and these mechanisms typically employed gear boxes with considerable backlash, thus making precise positioning and motions of the feeder tube very difficult. Moreover, in these arrangements, precise adjustment of the position of the feeder tube in a horizontal plane, in X and/or Y directions, was difficult to achieve in that the horizontal motions of the counterweight lift mechanisms could not be isolated along X or Y axes. Further, counterweighted lift mechanisms are cumbersome because of the dead weights employed in them, and the vertical feeder tube slide supports are subject to wear during up and down tube adjustments, which can impart a wobbling motion to the tube support system and thereby lead to undesired glass gob weight variation in a feeder bowl used in conjunction with a glass container forming machine of the individual section (I.S.) type. Also, from time to time, it is necessary to replace a feeder bowl itself. In the prior art, this required removal of the entire feeder tube mechanism itself.
BRIEF DESCRIPTION OF THE INVENTION
According to the present invention, the aforesaid and other problems associated with prior art glass forehearth feeder bowl feeder tube lift systems are avoided by a feeder tube lift system that employs a single, multiple shaft, servo motor operated, ball screw lift mechanism of sufficient capacity to sustain a cantilevered feeder tube support mechanism with minimal deflection. Such a lift mechanism involves no, or very little, backlash in its motions, thereby permitting precise control of the elevation of the lift tube in the feeder bowl, which is important in achieving accurate control of glass gob weight in an I.S. machine glass container manufacturing operation. The feeder tube lift mechanism of the present invention is also capable of true isolated adjustments in a horizontal plane, both along X and Y axes, and it can be moved without slide wear, thereby avoiding introduction of wobbling motion to the tube support system. The servo motor powered ball screw lift mechanism of the present invention is lubricated by a lubricant that is recirculated with a closed system to ensure long life for bearings of the mechanism and the ball roller nut, and avoiding lubricant leakage and the need for lubricant replacement.
Accordingly, it is an object of the present invention to provide an improved lift mechanism for a feeder tube of a type employed in a glass forehearth feeder bowl. More particularly, it is an object of the present invention to provide a lift mechanism of the foregoing type that is not counterweighted, and thereby avoids the problems associated with the prior art, of counterweighted feeder tube lift mechanisms.
For further understanding of the present invention and the objects thereof, attention is directed to the drawing and the following brief description thereof, to the detailed description of the preferred embodiment and to the appended claims.
REFERENCES:
patent: 3239326 (1966-03-01), Tyner
patent: 4514209 (1985-04-01), Mumford
patent: 4551163 (1985-11-01), Duga et al.
DiFrank Frank J.
Leidy D. Wayne
Rugh William B.
Owens-Brockway Glass Container Inc.
Vincent Sean
LandOfFree
Forehearth feeder tube lift system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Forehearth feeder tube lift system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Forehearth feeder tube lift system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608279