GB240823A - - Google Patents

Abstract

240,823. L÷ffler, S. Oct. 2, 1924, [Convention date]. Void [Published under Sect. 91 of the Act]. Refrigerating, cold - air machines for.-A machine particularly adapted for cooling small domestic refrigerators and for making ice in such refrigerators comprises a piston compressor 2 and expansion engine 4, Fig. 1 connected to the same crank-shaft 8, and driven at high speed, as by an electric motor 9. The cylinders are provided with rotary disc valves 3, 5 driven by pinion gear 10 from the shaft 8 or mounted directly on the shaft. The expansion cylinder 4 is provided with a jacket 6 through which the compressed air passes before it is sent through a cooler 7 and then to the inlet port d of the expansion cylinder, whereby the valve and cylinder ports are warmed sufficiently to prevent accumulation of snow from the moisture in the air. Alternatively, the air may be passed through the cooler 7 before entering the jacket 6. The air circulates in a closed cycle including the cold-chamber 1, and is compressed to a moderate pressure, for example less than three atmospheres. The cylinders are preferably arranged horizontally and opposed to one another. as shown. The working of the electric motor and the circulation of cooling-water may be controlled automatically according to the temperature in the cold-chamber. In a modification, shown in Fig. 2, a single cylinder 15 may be employed for both compression and expansion, the ports being controlled by a single rotary valve 3<1> driven by pinions 17 from the crank-shaft. The expansion takes place on the piston-rod side of the piston. The circulating air is kept free from contamination by oil &c. by encasing the driving-gear and by the employment of graphite or other self-lubricating piston rings. Lubrication may be afforded by the moisture contained in the air or by water admitted to the cylinders.