Refrigerating and Air Conditioning Pressure and Temperature Controls – Commercial
An early, crude, mechanically refrigerated cabinet temperature control, engineered with large “pan-cake” style hydraulic power element with large, built-in, thermal sensing bulb; open, single pole heavy copper switch contacts, mounted on steel plate base with press formed sheet steel cover, handsomely decorated in gold and black, Frigidaire, circa 1926.
Features:
Cover decorated in black with gold lettering, detailing monthly oiling instructions for condensing unit; Visual pleasing, unusual, oval, pressed steel cover with twin knurled brass hold-down nuts; Unusually rugged mechanical switch construction, with larger copper contact surfaces, a construction style which would soon disappear with the advent of increasingly smaller more finely engineered control technology, see for example ID # 165, code 7.02-10
Technical Significance:
An unusually crude, weighty and rugged, automated, mechanical switching device in iron plate and steel bolted construction, a quintessential product of Canada’s early period of industrialization. In its design and execution it appears, in many ways, much more like the product of a local blacksmith or iron monger than that of an industrial manufacturing process.
It stands as a classic marker and supreme accomplishments of its industrial times. Its significance is as an embryonic product of engineering and manufacturing know-how in the field of automated, electrical switching devices. It represented a know-how that would shortly be seen as the end of a genre. The genre would give way to a new generation of much more sophisticated engineering design concepts, made possible by a new generation of engineering theory building and practice, materials and manufacturing methods. See for example ID # 161 to 164.
Of special interest, in benchmarking and appreciating the technology represented here, is in contrasting it with micro-switch technology in common use in automated controllers in Canada by the 1950’s. The contrast in precision engineering, manufacture and performance represents a vast step ahead. See for example ID # 165, code 7.02-10
Industrial Significance:
See above