GB1436897A - Fabrication of fire damper units - Google Patents

Abstract

1436897 Making firedampers; bending J C KURZ 17 May 1973 [30 May 1972] 23630/73 Headings B3A and B3E [Also in Division A5] A method of making firedampers of the interlocking, folding blade type disclosed in Specification 1,428,992 includes supplying continuous strip material 30 to a roll forming station, roll forming the longitudinally extending edges 40, 42 of the strip into different, though complementary shapes, the rolls being adjustable to accommodate strip of different widths, and supplying the edge formed strip to a cutting station 52 where it is cut into predetermined lengths. The strip material 30 is fed to pairs of shaped rolls 38 on a first table 26, and a saw 54 cuts the strip into, e.g. 20 feet lengths for ease of handling, the lengths being fed to a second table 56. When a quantity of blade strip lengths has been formed, the lengths are fed back to the table 26 between guides 48, 50 and cut by the saw 54 to the length of the finished blades 14. To make a frame for the blades a coil of strip material (32b), Fig. 2B (not shown), is placed between the first table 26 and a third table 68, Fig. 2. The strip is fed to a punch press 70 which cuts the material into blanks (72), Fig. 4A (not shown) and simultaneously forms fingers (74) at one end of the blank and slits (84) on the other end. The blanks (72) are moved on the table 68 into alignment with a roll form 86, which forms flanges 88, 90, Fig. 4C, about a web portion 92 of the blank. The flanged blanks are directed across a fourth table 94 to a punch press 96 which forms aligned notches 98, 100, 102. The blank is bent about the notches into a rectangular configuration and a number of interlocked blades 14 are placed in the channel 92 defined between the flanges 88, 90. The ends of the frame are secured by engaging the fingers 74 in the slots 84 and bending them over, Fig. 1 (not shown). A pair of straps (20) are secured to the frame and they retain the blades in an open position by means of a fusible link (22). Blades of a smaller depth may be fabricated on the same apparatus by removing spacers 44 from between the pairs of rolls 38, the blades having identical edges to the blades 14. The frame strip coil (30c) for the smaller blades is mounted in alignment with roll dies 58 on the outboard section 36 of the roll form 24. The dies 58 bend the edges of the strip material to form spaced flanges (62), (64), interconnected by a web (66), Fig. 5A (not shown). The saw 54 cuts the formed strip to the desired length.