Refrigerating and Air Conditioning Pressure and Temperature Controls – Commercial
An early, crude, hydraulic bellows actuated, FHP, single pole, snap action, refrigeration system, low-side pressure/temperature controller, in black cast iron enclosure, configured and levered much like a door lock of the period, appearing much more like the product of a locksmith than a new generation of early 20th century, automatic electric control engineers [incomplete assembly], Penn, circa 1929.
Features:
Handsome, etched brass name plate decorated in black enamel; Full operating instructions and diagram on inside of cover plate
Technical Significance:
The controller, although itself an incomplete assembly, when seen in the context of the offerings by other suppliers to the field [see the range of other artifacts of the period held by HHCC in the 7.02 series], helps to demonstrate the wide range of engineering design concepts being offered by the industry, as it experimented with the materials and know-how of the times to respond to potential market needs, and to grow the industry.
This controller, much like the door lock, which seems to have inspired it, is a quintessential statement of serviceability. The cover plate, removable by means of a single wing nut, reveals the simplest of mechanical actions with levers and springs in door lock style.
To further reinforce the strongly held value of maintainablility and serviceability the inside of the cover plate carries a still very readable account of the control and its operation, along with a full drawing of the control showing all operating components.
Industrial Significance:
The control admirably demonstrates the lengths original equipment manufactures of the times went to assist, often ill trained field installation and service personnel to understand and maintain the equipment.