This invention is directed toward glass molding equipment, and more particularly, to an improved tong head assembly which allows for individual correction of misalignments between the grasping tongs of the assembly and the glass containers subjected to the grasping.
Tong head assemblies are used in glass molding equipment for grasping formed glass bottles and the like and moving the same from one position to another. The tong head assemblies are pneumatically driven such that a tong extending from the lower end of the assembly is caused to open and close onto a glass container or the like. The tong head assemblies employ a pneumatic cylinder located in a body member which is connected at its free end to a grasping tong. Upon movement of the cylinder, via air pressure or the like, the tongs are opened and closed for facilitating the grasping movement.
Frequently, and in most tong head assemblies, there are a plurality of cylinders having tongs thereon which are each adapted to grasp an individual glass container. As such, the individual cylinders and tongs must be in alignment with the glass containers which pass underneath the tong head assembly. Essentially, this alignment is established by the layout of the molds for the glass containers as well as the sizing of the tong head assembly and positioning of the individual cylinders thereon. However, as is inherent in all mechanical designs, tolerances, wear and the like inevitably add up to the loosening and relative movement of the parts of machines. As such, after this movement, the cylinder and grasping tongs tend to be out of alignment with the positions of the glass containers that the individual tong assemblies are adapted to grasp. Such movement adds up to the misalignment and the inability of the tong to grasp its respective glass container properly, thereby forming checks in the glassware or eventually breaking the same. Following from the aforementioned problems, the prior art includes a tong head assembly invention which allows for minor adjustments for aligning the tongs with their respective line of glass container positions.
U.S. Pat. No. 4,710,218 to Giberti-Fornaciari discloses a take-out tong head assembly. The take-out tong head assembly of this invention has means for adjusting the tongs. As such, the cylinders and tongs can be loosened from the body of the tong head assembly so that the tongs can be moved relative to the body so as to make the necessary adjustments for alignment. The bolts can be tightened for securing the tongs in the proper position. However, because the tongs of the Giberti-Fornaciari invention are substantially connected via the body of the assembly, both tongs of the assembly must be moved together to establish the proper adjustment. That is, movement of one tong in the lateral direction also moves the other tong. Because of this connection, independent tong adjustment for alignment with the position of its respective glass container is not possible. By moving one tong into position, it is possible, because of the interconnection of the two, to move the other tong out of position. Therefore, adjustments for perfect alignment of a tong with the glass containers to be grasped can be difficult or impossible.
Similarly, U.S. Pat. Nos. 4,185,985 to Wenz; 3,559,425 to Erwin et al.; and 1,859,956 to Canfield each disclose take-out assemblies for grasping and transporting glassware from a first position to a second position. However, none of these inventions discloses means for adjusting the take-out assemblies for correcting for misalignment with the subject glassware.