System for and method of applying a sealant strip to sheet material

A sealant strip application system for applying a sealant strip to a surface of a sheet of glass adjacent to a plurality of straight edges of the sheet of glass, each adjacent pair of the plurality of edges intersecting at a corner, the plurality of edges of the sheet of glass including a first edge and an adjacent second edge, the first edge having a first corner at a terminal end thereof and a second corner at the other terminal end thereof, and the second edge having the second corner at a terminal end thereof adjacent the first edge and a third corner at the other terminal end thereof, said sealant strip application system comprising:

• a support table having an upper surface and a straight front edge;
• said upper surface for supporting the sheet of glass at a lower surface thereof which is opposite the surface;
• said upper surface having an elongated opening therethrough which said elongated opening extends at an angle with respect to said front edge of said support table;
• a vacuum cup device mounted relative to said support table to extend through said elongated opening in alignment with said upper surface and for movement along said elongated opening toward and away from said front edge;
• gripping vacuum means for being selectively applied by said vacuum cup device to the lower surface of the sheet of glass for gripping the sheet of glass in a central region thereof without allowing any relative movement between said vacuum cup device and the sheet of glass throughout the application of the sealant strip to the surface of the sheet of glass;
• a sealant strip applicator mounted on said support table for movement along said front edge;
• means for feeding the sealant strip to said sealant strip applicator;
• said sealant strip applicator having selective strip applying means for being activated to apply the sealant strip to the surface of the sheet of glass and for being deactivated to discontinue the application of the sealant strip to the surface of the sheet of glass;
• a variable coupling element between said sealant strip applicator and said vacuum cup device;
• said variable coupling element including selective coupling means for being activated to establish a fixed distance of said sealant strip applicator from said vacuum cup device and a fixed direction of said sealant strip applicator from said vacuum cup device and for being deactivated to allow a variable distance and a variable direction of said sealant strip applicator from said vacuum cup device;
• said sealant strip applicator for being initially positioned at the first corner of the sheet of glass when the first edge is parallel to and in alignment with said front edge of said support table;
• said selective coupling means for being deactivated and said selective strip applying means for being activated when said sealant strip applicator is positioned at the first corner;
• said sealant strip applicator for being moved relative to said front edge of said support table in a first direction from the first corner toward the second corner of the sheet of glass as the sealant strip is applied to the surface adjacent to the first edge when said selective coupling means is deactivated and said selective strip applying means is activated;
• said sealant strip applicator for being positioned at the second corner of the sheet of glass after the application of the sealant strip along the first edge of the sheet of glass;
• said selective coupling means for being activated and said selective strip applying means for being deactivated when said sealant strip applicator is positioned at the second corner;
• said sealant strip applicator for being moved in a second direction opposite said first direction relative to said front edge, after activation of said selective coupling means and deactivation of said selective strip applying means, to cause said vacuum cup device to rotate the sheet of glass on said upper surface of said support table about the central region until the second edge is in general alignment with said front edge of said support table as said vacuum cup device initially moves along said elongated opening away from said front edge and then moves along said elongated opening toward said front edge;
• said selective coupling means for being deactivated and said selective strip applying means for being activated when said second edge is parallel to and in alignment with said front edge and said sealant strip applicator is positioned at the second corner for being moved relative to said front edge of said support table in said first direction toward the third corner of the sheet of glass for the application of the sealant strip to the surface of the sheet of glass adjacent to and along the second edge;
• said sealant strip applicator including bending pin means extending toward the surface of the sheet of glass in a direction generally perpendicular thereto at a side of the sealant strip away from said front edge of said support table;
• said bending pin means for bending the sealant strip at the second corner of the sheet of glass as the sealant strip applicator is moved in said second direction;
• a normally open switch associated with said selective coupling means and said selective strip applying means for being open to cause deactivation of said selective coupling means and activation of said selective strip applying means and for being closed to cause activation of said selective coupling means and deactivation of said selective strip applying means;
• and
• selective alignment retaining means for retaining the first edge of the sheet of glass parallel to and in alignment with said front edge when said sealant strip applicator is being moved in said first direction and for allowing the rotation of the sheet of glass when said sealant strip applicator is being moved in said second direction.

A method of applying a sealant strip to a surface of a sheet of glass adjacent to a plurality of straight edges of the sheet of glass, each adjacent pair of the plurality of edges intersecting at a corner, the plurality of edges of the sheet of glass including a first edge and an adjacent second edge, the first edge having a first corner at a terminal end thereof and a second corner at the other terminal end thereof, and the second edge having the second corner at a terminal end thereof adjacent the first edge and a third corner at the other terminal end thereof, said method comprising the steps of:

• supporting the sheet of glass at a lower surface thereof which is opposite the surface on an upper surface of a support table having a straight front edge;
• gripping the lower surface of the sheet of glass in a central region thereof to allow limited movement of the central region toward and away from said front edge along a path which is at an angle with respect to said front edge;
• mounting a sealant strip applicator on said support table for movement along said front edge;
• selectively applying the sealant strip to the surface of the sheet of glass with said sealant strip applicator;
• selectively discontinuing the application of the sealant strip to the surface of the sheet of glass by said sealant strip applicator;
• selectively coupling said sealant strip applicator and the central region of the lower side of the sheet of glass to establish a fixed distance of said sealant strip applicator from the central region and a fixed direction of said sealant strip applicator from the central region;
• selectively uncoupling said sealant strip applicator and the central region of the lower side of the sheet of glass to allow a variable distance and a variable direction of said sealant strip applicator from the central region;
• initially positioning said sealant strip applicator at the first corner of the sheet of glass when the first edge is parallel to and in alignment with said front edge of said support table during said selective uncoupling;
• initially moving said sealant strip applicator relative to said front edge of said support table in a first direction from the first corner toward the second corner of the sheet of glass during said selectively applying the sealant strip to the surface adjacent to the first edge;
• subsequently positioning said sealant strip applicator at the second corner of the sheet of glass after said selectively applying the sealant strip along the first edge of the sheet of glass;
• subsequently moving said sealant strip applicator in a second direction opposite said first direction relative to said front edge, during said selectively coupling and said selectively discontinuing the application of the sealant strip, to cause rotating of the sheet of glass around the central region on said upper surface of said support table until the second edge is generally parallel to said front edge of said support table;
• said subsequently moving said sealant strip applicator in said second direction initially causing the central region to move along said path away from said front edge and then to move along said path toward said front edge;
• bending the sealant strip at the second corner of the sheet of glass during said subsequently moving said sealant strip applicator in said second direction;
• and
• repeating the steps of said selectively uncoupling and said selectively applying said sealant strip to the surface of the sheet of glass adjacent to and along the second edge when said sealant strip applicator is positioned at the second corner for repeating said initially moving said sealant strip applicator relative to said front edge of said support table in said first direction toward the third corner when the second edge is parallel to and in alignment with said front edge.