Apparatus and methods for placement of angle plates in transverse duct flanges are known and disclosed in U.S. Pat. Nos. 5,283,944; 5,321,880; and 5,342,100, the disclosures of these patents being incorporated in their entirety herein by reference. Commercial apparatus using the inventions of these patents have been sold under the trademark CORNERMATIC® by the Iowa Precision Industries Division of Mestek Machinery, Inc. (“IPI”). These machines have been commercially successful and have transformed the industry with respect to the insertion of angle plates into duct work. Additionally, U.S. Pat. No. 5,926,937 discloses a mobile apparatus for placement of angle plates in transverse duct flanges, the disclosure therein being incorporated in its entirety herein by reference. This latter patented technology has been manufactured commercially by IPI and sold under the trademark CORNER CADET®.
The CORNERMATIC® and CORNER CADET® apparatus and methods have been commercially successful. They have saved the industry substantial time and money and made the insertion of angle plates into ducts substantially easier for sheet metal fabricators, including saving wear and tear on the human body. However, the CORNERMATIC® and CORNER CADET® machines usually cannot accept irregular shaped duct fittings referred to in the industry and herein as “fittings.” For example, FIG. 1 shows duct fitting D and its irregular shape. Additionally, fitting D includes Pittsburgh locks PL at the corners of the duct. Referring to FIG. 2, there is shown the fitting D of FIG. 1 and the IPI CORNER CADET® machine. As shown in FIG. 2, the fitting D will not fit into the machine for the automatic insertion of angle plates AP. As seen, the top of the fitting will contact the angle plate supply hopper H of the machine and/or the fitting will contact the press member P of the machine. This prevents the duct flanges F from being positioned in the machine such that the fitting may be clamped in place by clamp C, receive an angle plate AP, the angle plate thereafter pressed into the flange by press member P and a subsequent crimping operation. Workers must, therefore, manually insert the angle plates into the flanges of fittings and then hammer the angle plate into the fitting, and thereafter “crimp” the duct flange by further hammering the flange over the angle plate. Accordingly, the worker spends substantial time in such insertion, slowing down operations, causing expense to the fabricating shop, causing potential damage to the flange and wear and tear on the human body.
Additionally, the fabrication of duct work, including fittings, is not always precise and the duct flanges may be bent or the corners of the duct are of an irregular shape. For example, referring to FIG. 3, there is shown a partial section of duct D having at Pittsburgh lock PL and flanges F. The duct D is not precise in its fabrication, including at the Pittsburgh lock PL, and angle plate AP will not fit properly into the flange leaving a space S. In such instances, the CORNERMATIC® and CORNER CADET® machines may have difficulty in automatically inserting angle plates into the duct flange or may not be able to automatically insert the angle plate. In the latter situation, the angle plate must be removed and manually inserted, thereby causing additional time for the worker, expense to the duct fabrication shop and potential damage to the flange.
The CORNERMATIC® and CORNER CADET® machines include supply hoppers which feed the angle plates. These hoppers are above the angle plate feed mechanism which slides an angle plate from the bottom of a stack in the hopper into the duct flange. With respect to the CORNERMATIC® and CORNER CADET® machines, the hopper may be in the way of a duct fitting precluding the automatic insertion of an angle plate as referenced above in FIG. 2 and requiring the manual insertion by the worker.
Referring to FIG. 4, there is shown an angle plate 12 useful in the CORNERMATIC® and CORNER CADET® machines and manufactured and sold by IPI and Ductmate Industries, Inc. (“Ductmate”) under the trademark CORNERMATIC®. These angle plates come in different dimensions for use in either TDC or TDF duct flanges. The angle plates are sold in cartons of 250 angle plates. The angle plates are stacked in ten columns of twenty-five. The worker must take each column of twenty-five angle plates from the carton using a metal rod placed through bolt hole opening 18 of the angle plate, or by hand, and hand load each column into the angle plate supply hopper of the CORNERMATIC® and CORNER CADET® machines. In some instances, after a number of columns from the carton are loaded, the remaining columns fall over, thereby requiring the loading of the angle plates individually or in small groups. While these machines have saved the industry substantial time and expense, the hand loading of the angle plates still takes time. Accordingly, there is room for improvement to the packaging and loading of angle plates.
In duct fabrication plants, the duct work is first formed and thereafter the angle plates are inserted into the duct work. Presently, each duct fabrication shop is set up differently, and there is no method for a work flow comprising an orderly and economical manufacture of the duct fittings and the automatic insertion of angle plates into the fittings.
Accordingly, while the CORNERMATIC® and CORNER CADET® machines have been an extremely successful “work-horse” in duct fabricating shops, improvement to these machines and methods of use is possible. This is applicable for, among other things, insertion of angle plates into fittings; the automatic insertion of angle plates into duct flanges which are not precise in manufacture or which are bent; and the packaging and loading of angle plates. There is also a need for a method of the work flow in duct fabrication shops to efficiently and economically fabricate fittings and automatically insert angle plates therein.