Patent GB-805711-A (GB)
Title: Improvements in or relating to machine for making blocks of ice
IPC: F25C1/24
Filed: 1956-08-08
Abstract: 805,711. Ice-making. BORG-WARNER CORPORATION. Aug. 8, 1956 [Aug. 15, 1955], No. 24270/56. Class 29 The invention relates to an ice-making machine for mounting in the freezer compartment of a domestic refrigerator and includes power operated means to free and harvest the ice blocks from the ice tray. The machine includes a tray 10 fixed to the side wall of the freezer compartment and having a movable grid, and an ice motor 17 by which the ice is freed from the tray and which operates microswitch 87, and, indirectly, microswitch 89, respectively controlling a solenoid water input valve 97 and an electric motor 21 by which the ice is harvested into a basket 26 by rotation of the grid about a central shaft 19. The grid comprises a longitudinal vertical divider 14, lateral dividers 16 loosely fitted to 14 and a horizontal plate 15 located asymmetrically on 14 and slotted to engage the lateral dividers 16. The divider 14 has an upstanding lug 39 passing through slots in the plate 15 and the shaft 19, a pin 44 on the latter sliding in a slot on the lug 39. A yoke 47 is fixed to the end of the plate 15 remote from lug 39, embracing shaft 19 so that only movement substantially in one plane relative to shaft 19 is possible to the yoke, and having a pin and slot connection with the divider 14. A hollow shaft 35 is splined to the shaft 19 and fixed to the yoke 47 and at the other end splined to a coupling 91 connected to the drive of the electric motor 21. The shaft 35 can move freely through a bearing 38 against the action of a spring 93 and carries a cam 84 having cam surfaces associated with followers 94 and 96 connected to microswitches 89, 87. The ice motor 17 comprises a liquid filled hollow rod 68 engaging at one end the lug 39 and carrying at the other end a piston 71 fixed to the horizontal plate 15. The liquid is preferably water or a mixture of water and sodium nitrate or sodium metasilicate. Fresh water supply to the ice tray direct from the mains or from a reservoir in the refrigerator cabinet is led through pipes 104 and 106 and the solenoid valve 97 to a discharge pipe 98 with orifices which may be kept free from ice by a small electric heater. In operation the freezing takes place more slowly in the liquid of the ice motor 17 than the water of the tray 10 due to heat rising from the tray. The expansion of the liquid in the motor on freezing moves the piston 71 to the right and thus the plate 15, and the dividers 16 relative to the vertical dividers 14 which is moved upwardly to free the ice from the bottom of the tray. Additionally, the shaft 35 is caused to move to the right operating the microswitch 89 which starts the electric motor 21. This slowly rotates the grid about the shaft 19 when the cams 24 free the ice blocks completely from the grid and harvest them into the basket 26. Meanwhile the switch 87 has been operated and the tray 10 is refilled with water. On completion of one revolution the switches 87 and 89 are opened and the process restarts. The basket 26 rests on springs, the weight of ice therein opening a switch 113 in the main power supply when sufficient cubes have been obtained.