The present invention relates to glassware forming machines, and more particularly to the curvature of the deflector that directs molten glass gobs into the blank mold of a glassware forming machine.
In individual section glassware forming machines, mold charges or gobs of molten glass are fed by a gob distributor along troughs to the machine sections in sequence, and then by deflectors at each machine section into the blank molds at that section. The deflectors have an arcuate contour to convert the downwardly angled motion along the troughs to vertical motion into the blank molds. U.S. Pat. No. 4,772,306 teaches that the centerline of the deflector lies along a spiral curve in which the radius varies as a function of angle. Thus, in
A major concern in the design of gob deflectors is the normal or radial force exerted by the deflector on the gob due to centrifugal acceleration during travel of the glass gob along the deflector. A positive normal force throughout travel along the deflector is necessary to maintain control of the gob, and to control loading of the gob into the blank mold. However, excessive normal force increases heat transfer from the gob to the deflector, increases friction between the gob and the surface of the deflector, causes greater elongation of the gob, and cools the gob on the side in contact with the deflector, which undesirably can lead to distortion of the blow molded glass container. Furthermore, a high normal force at the exit end of the deflector would allow the gob to continue to travel outward as the gob leaves the exit end of the deflector, rather than vertically downwardly into the associated blank mold. A general object of the present invention is to provide a gob deflector that addresses these areas of concern.
In accordance with the present invention the curved portion of the deflector is defined by two spiral curves that connect at a central portion of the deflector. The spiral curves are reflected about a line perpendicular to the intersection of the two curves, so that the minimum radius of each spiral curve is at the point where the curves meet. The exponent P and constant C for each curve can be specified independently.
Thus, a gob deflector in accordance with one aspect of the present invention has an entry end for receiving molten glass gobs, an exit end for directing the glass gobs into a blank mold of a glassware forming machine, and a curved portion between the entry and exit ends. The curved portion has an arc defined by an upper curve contiguous with the entry end of the deflector and a lower curve contiguous with the exit end of the deflector. The upper and lower curves have radii as differing functions of angle along the curved portion of the deflector.
In the preferred embodiments of the invention, the lower curve adjacent to the exit end of the deflector is defined by the equation r1=C1/θ1P1, where r1 is the radius at angle θ1, and C1 and P1 are constants. The upper curve adjacent to the entry end of the deflector is defined by the equation r2=C2/θ2P2, where r2 is the radius at angle θ2, and C2 and P2 are constants. The curves have minimum radii r1min=r2min where the curves meet at the central portion of the deflector curved portion. At least one of the constants P1 and P2 is non-zero. In the preferred embodiments, the constant P1 is non-zero, and the constant P2 may be non-zero or may be equal to zero such that the upper curve has a constant radius r2=C2.
The invention, together with additional objects, features, advantages and aspects thereof, will best be understood from the following description, the appended claims and the accompanying drawings, in which:
Intersection height a for each deflector is 29.958 inches, and trough angle φ for each design is 24 degrees.
There thus has been disclosed a gob deflector that fully achieves all of the objects and aims previously set forth. The present invention has been disclosed in conjunction with a number of presently preferred embodiments, and various modifications and variations have been discussed. Other modifications and variations readily will suggest themselves to persons of ordinary skill in the art without departing from the scope of the present invention. The present invention is intended to embrace all such modifications and variations as fall within the spirit and broad scope of the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
4529431 | Mumford | Jul 1985 | A |
4772306 | Davey et al. | Sep 1988 | A |
5213602 | Foster et al. | May 1993 | A |
5254150 | Riemer et al. | Oct 1993 | A |
5298049 | Meyer | Mar 1994 | A |
5549727 | Meyer | Aug 1996 | A |
5599370 | Struckmeier et al. | Feb 1997 | A |
5824129 | Struckmeier et al. | Oct 1998 | A |
5846283 | Struckmeier et al. | Dec 1998 | A |
5888267 | Schumann et al. | Mar 1999 | A |
5935287 | Graefe et al. | Aug 1999 | A |
6038888 | Flynn et al. | Mar 2000 | A |
Number | Date | Country |
---|---|---|
101 52 962 | May 2003 | DE |
Number | Date | Country | |
---|---|---|---|
20060075785 A1 | Apr 2006 | US |