GB730299A - Improvements in or relating to electric air heating and circulating apparatus - Google Patents

Abstract

730,299. Unit air heaters. ELECTRIC & MUSICAL INDUSTRIES, Ltd. July 31, 1953 [July 31, 1952], No. 19356/52. Class 137. [Also in Group XI] An electric air heater, in which a fan 27 induces air to flow over electric heating means, e.g. elements 17, 18 which are controllable to provide at least two degrees of heating, has means for varying the speed of the fan 27, and a member, e.g. a lever 46, for controlling and deenergizing the elements 17, 18, the lever 46 being interconnected with the means for varying the fan speed, whereby an increase in the heat output is accompanied by an augmented air flow, and vice versa, and, when the lever 46 is adjusted to de-energize the elements 17, 18, the fan 27 is adjusted to increase the air flow to a value greater than when the elements 17, 18 are energized. The heater comprises a base 1, top 2, and intermediate parts 3 having louvres 4, air being drawn in at the back of the heater, passing over the elements 17, 18 mounted in parallel between metal plates 12, 14, e.g. as described in Specification 588,839, and leaving by apertures 10. The fan 27 is driven by an electric motor 28, and is of the axial flow induction type. The sector-shaped lever 46 controls a switch which has four positions (see Group XI). In one position the elements 17, 18 and motor 28 are de-energized; in a second position the fan receives full voltage, e.g. 250 V., the elements 17, 18 remaining " off " ; in a third position the element 17 is energized, the fan receiving 150 V.; in a fourth position the elements 17, 18 are energized in parallel, and the fan receives 200 V. In the second position a rod 38 mechanically operated by the lever 46 acts through a bar 6 to raise the louvres 4 to their upper positions 4a. In all other positions the louvres 4 are down, deflecting the warm air of positions three and four onto the floor. Specifications 484,720 and 713,773, [Group XXXVII], are referred to.