Industrial and commercial storage tanks facilitate trade and are an integral part of modern commerce. From water processing and dry commodities to oil and frac sand, storage tanks are an essential component of a variety of industries. Yet despite the widespread use and impact of storage tanks, tank production remains much the same as it was 100 years ago. Sheets are cut from steel plates of varying thickness and manipulated to match the desired tank dimensions.
One of the first steps in building a storage tank is to properly position the metal panels that will be welded together to form the tank itself. The metal panels are often large, heavy steel sheets that are moved into place by a crane. While the metal sheet is still attached to the crane, workers help guide the sheet into the proper location so that the metal sheets may be welded together. To stay on schedule, workers must position the metal sheets quickly so that the crane can lift more metal sheets to be laid in position. Because most tank building takes place outdoors, workers are subjected to nature's elements. Wind, rain, and other weather conditions make the positioning of metal sheets difficult and unsafe. For example, high winds often cause metal sheets suspended from a crane to sway. Additionally, heavy rain can cause the workers' tools to slip.
Even in good weather, the metal panel will rarely be correctly positioned after it is released from the crane. Workers must therefore exert great force and strength to move the panels into place. Workers currently use various types of crowbars to align the large steel panels. This process is extremely labor intensive and time consuming. It requires workers to bend down and exert great amounts of pressure on their backs, legs, and arms as they push and pry the metal sheets. In inclement weather, the task of moving the large metal sheets becomes even more difficult because the crowbars are slippery.
Crowbars are the most common method of metal plate alignment in the storage tank industry. Dowel pins, or locating pins, provide another method of plate alignment. The pins are strategically placed so two pieces of sheet metal are aligned properly until they are welded or bolted together. After the tank is assembled, the dowel pins are removed and the holes are sealed with a weld. Although dowel pins are useful for more exact metal sheet positioning, workers still must use crowbars or similar methods to position the metal in place before inserting the dowel pins. Furthermore, the dowel pins must be removed and the holes welded over before the tank is finished. Additionally, the weight of the large metal sheets may bend or break the dowel pins. Dowel rods thus slow the process of tank building, and the dowel rods themselves are useful only for holding the sheets together, not for positioning the sheets in place.
Embodiments of the invention will not be limited to storage tank production. A version of the invention will generally find utility in any application that requires incremental positioning. One embodiment of the invention is aimed at incrementally moving large and heavy pieces of metal, and a version of the invention may be utilized in many applications in which the incremental positioning of metal is desired. Such applications include, but are not limited to, ship and vessel building, defense building applications, aerospace and airplane construction, and the like. In all industries, the current method of metal positioning is based on the highly labor intensive use of crow and pry bars.
Thus, a need exists in the art for a device that eases the process of positioning large metal sheets. Furthermore, a device that utilizes tools already in use is preferred, and, as in all fields, advancements in the art are desired.