Patent GB-998056-A (GB)
Title: Ice block making apparatus
Inventor: BECK GEORGE WILLIAM
IPC: F25C1/04
Filed: 1963-12-06
Abstract: 998,056. Ice making. GENERAL MOTORS CORPORATION. Dec. 6, 1963, No. 48266/63. Heading F4H. In ice block making apparatus a resilient flexible ice block tray is twisted to loosen ice blocks, tipped to eject the blocks, then reverse twisted to remove warping caused by the initial twisting. As illustrated, the ice is made in a compartment cooled by an evaporator 16 (Fig. 2), over which air is circulated. The ice tray 25 is mounted in a bracket fixed to one wall of the compartment and is provided with cleats 33 one of which is freely pivoted to a pin 37 and the other of which engages the squaresection shaft 43 of a drive mechanism. Below the ice tray is an ice-collecting box 115 which slides into place on flanges 127. On one side of the box a leaf spring 134 is located above a flange 127 (Figs. 4 and 5) so that when the box is full it is lowered to a position in which an arm 116, which is normally held in the full line, Fig. 5, position by a shoulder 131 on a handle of the box, is moved to the dotted, Fig. 5, position by a spring 142 thus separating contacts 105 and 106 (Fig. 8) through a lever 121 to prevent further ice being tipped into the box. Temperature in the ice tray is sensed by a thermistor 155 (Figs. 4 and 11) and as the temperature falls the resistance of the thermistor is increased until the current through a coil 169 is sufficient to close a switch 171 thus starting a motor 52 which, through gearing, drives a toothed disc 67 having a cam track 73 engaged by a cam follower on a freely pivoted segment 75. Teeth 77 on the segment engage a gearwheel on the shaft 43 and the shape of the cam track is such that in one rotation it turns the ice tray first clockwise from its Fig. 5 position, the free end of the tray being held in the horizontal position by a stop, thus twisting the tray to loosen the ice blocks, then twisting the tray anticlockwise, the free end turning through 90 degrees to engage a further stop, to tip out the blocks, then twists the tray against the latter stop to remove warping, and finally rights the tray. A further disc 89 (Fig. 8), is mounted on the shaft 68 of the disc 67 and engages a spring arm 102 of a switch assembly 101. Fig. 8 shows the normal rest position of the disc. As it rotates from this position, contacts between switch arms 103 and 104 are closed to by-pass the motor switch 171. When a shoulder 91 on the disc 89 engages the arm 102 a pin 109 on the arm 103 is depressed to separate contacts on arms 105 and 106 (the motor continuing to run by virtue of the by-pass round switch 171) and close contacts between arms 106 and 107 thus opening an electromagnetic valve 151 to supply water through a pipe 149 to the tray. The valve 151 remains open until a shoulder 92 on the disc 89 passes the arm 102. Finally, a projection 93 momentarily opens the valve 151 and the engagement of a flat 97 on the disc 89 with the arm 102 releases contacts 103 and 104 and the cycle is completed and the motor stops. When the ice box 115 is full contacts 105 and 106 are separated as stated above so that the switch 171 cannot be closed to start the motor. Fixed fingers may be provided to engage the ice blocks as the tray is tipped to assist in their removal.