GB1114582A - Improvements relating to pump assemblies - Google Patents

Abstract

1,114,582. Mixing and aerating apparatus. T. GIUSTI & SON Ltd. 15 July, 1966 [l5 July, 1965], No. 30103/65. Heading BIC. [Also in Division Fl] A pump 11, Fig. 1, for producing a mixture of ice cream mixture and air for delivery to a freezing drum 1 comprises a pumping chamber for air and a pumping chamber of smaller capacity for ice cream mixture, and a common piston which acts to discharge the ice cream mixture from its pumping chamber into an adjustable quantity of air in the air pumping chamber, and then to discharge the mixture of air and ice cream mixture. In the Fig. 2 embodiment, the pump comprises an ice cream mixture pumping chamber 60 and an air pumping chamber 42. A stepped piston 24 draws ice cream mixture through valve 38 and air through adjustable valve 67 on its right-hand stroke, and, on its left-hand stroke, the ice cream mixture is transferred through a valved passage (43), Fig. 3 (not shown), into air chamber 42 and the air and ice cream mixture is discharged through valve 61. The proportion of air in the mixture is adjusted by a nut 65 controlling the spring loading on air valve 67. In the Fig. 4 embodiment, a bucket piston 73 has a valved passage 106 connecting ice cream mixture chamber 84 to air chamber 76, ice cream mixture being drawn into chamber 84 through valve 102 during the left-hand stroke and discharged into air chamber 76 during the right-hand stroke. Air is also drawn into chamber 76 through valve 121 during the right-hand stroke, and the mixture of air and ice cream mixture is discharged from chamber 76 through valve 113 during the next left-hand stroke. The freezing drum 1, Fig. 1, comprises a double-walled cylinder with its interwall space 4 included in a refrigeration circuit. A dasher 7 within the drum has scrapers 6 and is driven by a motor 17. The scrapers scrape the frozen film from the drum inner wall 2, and the dasher impels the frozen mixture towards the drum outlet 9.