GB984697A - Transverse-flow fan - Google Patents

Abstract

984,697. Transverse-flow fans. ENGELHARD HANOVIA Inc. Jan. 23, 1962 [Jan. 26, 1961], No. 2530/62. Heading F1C. [Also in Division F4] A transverse-flow fan comprises a pair of elongated baffle assemblies, one at each side of the rotor to define a conduit through which air is conveyed, each baffle assembly including a pair of substantially flat strips movably joined together at one edge to form a hinge, and means for shifting each hinge selectively between two alternative positions, in one of which the hinge is close to the rotor surface and in other of which it is spaced away from the rotor, the remainder of each of the baffle assemblies being spaced away from the rotor in both positions of the hinge. By this means, the direction of flow through the fan can be reversed without reversing the direction of rotation of the rotor. In the fan shown in Figs. 5 and 6, two diametrically opposed baffles for guiding the flow through the rotor 10 respectively comprise flat strips 20, 22 hinged together on a hinge pin 56 and flat strips 24, 26 hinged together on a hinge pin 58. The pins 56, 58 are extended at each end to engage vertical slots 48, 50 in each casing side wall 42, 44. Pegs 68, 70, 72, 74 secured to the strips engage horizontal slots 60, 62, 64, 66. In the positions shown, in which pin 56 is close to the rotor periphery and pin 58 is remote from the rotor, the air flows from left to right of Fig. 5. To reverse the direction of flow, the pins 56, 58 are moved to the upper ends of the slots 48, 50, the hinged baffles then assuming positions similar to those that can be seen by inverting Fig. 5. To effect the reversal, there may be provided a bar 76 having a handle 82 and continuing into vertical arms 78, 80, each arm having bores receiving the pins 56, 58. The arms may be held frictionally in the two positions of adjustment by means of springs 90, 92. Since the inlet and outlet zones of the fan are separated from one another only by a narrow edge of the baffle positioned nearest the rotor periphery, with each space between adjacent rotor blades 12, when facing the baffle, communicating simultaneously with both zones, there is little tendency for the return of air from the outlet zone to the inlet zone through the region of the rotor obstructed by the baffle. This reduces turbulence and noise. In a transverse-flow fan described for explanatory purposes but not included within the scope of the invention, the two diametrically opposed baffles comprise radially disposed strips 14, 16, Fig. 1. Reversal of flow is obtained by radially moving the strips so that strip 16 is brought close to the periphery of the rotor 10 and the strip 14 is correspondingly withdrawn from the periphery. Or, the rotor 10 may be shifted to bring its periphery close to the strip 16. As a further alternative, both baffles may be rotated about an axis which is eccentric with respect to the rotor axis. The shift may be smaller or greater than 180 degrees to provide a corresponding change of direction of flow.