Patent GB-1433521-A (GB)
Title: Induction air conditioning apparatus
IPC: F24F11/02
Filed: 1973-02-27
Abstract: 1433521 Releasable fastenings MARLO SpA 27 Feb 1973 [1 March 1973] 9640/73 Headings E2A and E2M [Also in Divisions F2 F3 F4 G2 and G3] Induction air heating or cooling apparatus comprises a primary air plenum chamber 1, nozzles 4 through which primary air is discharged to induce secondary air flow through a heating heat exchanger 11 or a cooling heat exchanger 8, the secondary air flow being controlled by pivotally mounted dampers 17, 13 actuated by inflatable bladders 18, 14 supplied with primary air via a valve assembly 34 controlled by a room thermostat 36. In the form shown, a by-pass passage 10 for secondary air located between the heat exchangers 8, 11 includes a damper 21. The dampers are spring biased to their open positions. The valve assembly 34 includes a port 49 connected to the plenum chamber 1, ports 50, 51 connected to the bladders 14, 18 respectively, ribbed slides 41, 42, shutter plates 43, 44 and springs 45, 46 all slidably mounted on a pin 47, and a finger 48 secured to the bimetallic element 36 and extending between the springs 45, 46. Several induction apparatuses may be controlled by a single valve assembly 34. The dampers 17, 13 and 21 are linked so that when one of the dampers 17, 13 is at least partially open the other is held in a closed position, and so that the damper 21 is moved to close the passage 10 as either of the dampers 17, 13 is moved to an open position. The damper 21 and a gear sector 32 are fixedly mounted on a pivot 24 and two levers 57, 57' having pawls 58, 58' and brackets 59, 59' extending therefrom are pivotally mounted on the pivot 24. The dampers 13, 17 are mounted on pivots 22, 23 which are attached through cranks 26, 27 and rods 28, 29 whose lengths can be varied to racks 30, 31 which are toothed over a portion of their lengths and are pressed into contact with gear sector 32 by rollers 64, 65 on a shaft 63. The brackets 59, 59' on levers 57, 57' are biased by springs 60', 60 into contact with respectively the lower end of rack 31 and the upper end of rack 30, and are disengageable upon rotation of levers 57, 57' by projections 61, 61' on racks 30, 31 engaging the pawls 58, 58'. In the position of the shutter plates 43, 44 shown in Fig. 2a, dampers 13, 17 are in closed positions a-a and b-b. Pawls 58, 58' are engaged by projections 61, 61' so that both rods 28, 29 are free to move. Upon a demand for cooling, for example, the shutter plate 43 is moved to a position preventing communication between ports 49 and 50, whereupon the bladder 14 collapses and 'the damper 13 is moved towards an open position by a spring 16. As the damper 13 is opened, the pawl 58 is released and bracket 59 is urged by spring 60' into contact with the lower end of rack 31 to hold the damper 17 in its closed position, and the rack 30 turns the damper 21 from its rest position c"'-c"' towards a closed position c'-c'. Upon a demand for heating, the damper 13 is moved to its closed position, whereupon the pawl 58 is depressed and the bracket 59 moved to free the rack 31. The damper 17 is then moved towards an open position, producing simultaneous movement of damper 21 from its rest position c"'-c'" towards a closed position c"-c". As the rack 31 moves downwardly, the pawl 58' is released and the bracket 59' engages the upper end of rack 30 to hold the damper 13 in its closed position. Reference has been directed by the comptroller to Specification 1105494.