Retractable column and method of forming
The present invention is an improved apparatus and method for forming a retractable tower or column. The present invention includes pointed hooks wherein the hooks are attached to each section of a section chain, one in a horizontal direction and one in an off-set manner. The section chains are placed on a take up mechanism in an operable position and then raised utilizing a motor. As the section chains are raised, they are guided by a guide tower, rollers, shims, and gear racks into a position whereby hooks from adjacent sections of the section chains form coupled engagements. The coupled engagement of the hooks of the sections of each adjacent section chains thereby form the column.
1. A method for erecting a retractable tower, the method comprising the steps of:
providing a plurality of chains wherein each chain is formed from at least two vertically adjacent individual sections, each section having an outer surface, and vertically adjacent sections being pivotally mounted to each other to pivot about a pivot axis;
providing first and second hooks mounted to lateral sides of each individual section, each hook including a cylindrical rod portion with a central axis and a curved hook portion for lockably engaging the curved hook portion of a laterally adjacent hook, the cylindrical rod portions of the first and second hooks of each individual section being substantially on and parallel to the pivot axis of that section; wherein the curved hook portion of each hook is angled relative to the rod portion and the curved hook portion defines a plane which is angled relative to the central axis of the rod portion;
lifting the plurality of chains so as to cause the pivot axes of laterally adjacent sections to lie substantially within a common plane thereby moving the hook portions of laterally adjacent sections to lockably engage with one another to couple the adjacent chains together with the outer surfaces of the sections of each chain forming a face of the tower;
angling the curved hook portion of each hook relative to the rod portion with the curved hook portion defining a plane which is angled relative to the central axis of the rod portion;
positioning the first and second hooks on individual sections to have the angled hook portions of lockably engaging hooks of laterally adjacent sections engage each other as the chains are lifted; and
angling the hook portion at an acute angle relative to the axis of the cylindrical rod.