GB977699A - Improvements in or relating to ice-making apparatus - Google Patents

Abstract

977,699. Ice-making. DOLE VALVE CO. Nov. 5, 1963, No. 43703/63. Heading F4H. Ice-making apparatus comprises first and second shafts, a flexible ice tray mounted on the second shaft, co-operable first and second drive elements mounted on the first and second shafts respectively, said drive elements being arranged to describe intersecting arcuate paths on rotation thereof, and means for rotating the first shaft. As shown in Fig. 3, a flexible polyethylene ice tray 11 is mounted at one end on a shaft 24 journalled in a support 20 and at the other end on a shaft 25 journalled in a support 21. A motor 45 is mounted on support 20 in spaced relation therewith and has a drive shaft 48 the axis of which is disposed below that of shaft 24 (Fig. 4, not shown). Crank arms 40 and 50 having fingers 41 and 51 are mounted on shafts 24 and 48 respectively and are so arranged that rotation of shaft 48 is transmitted to shaft 24 until the shaft 48 has rotated through approximately 140 degrees when the fingers 41 and 51 slide out of engagement due to the eccentricity of arms 40 and 50. When this point is reached, a spring 42 returns the ice-tray to its horizontal position. A stop (not shown) is mounted on support 21 and is contacted by the corner of the ice-tray when the latter has rotated through about 120 degrees so that the remaining 20 degrees of rotation cause flexure of the tray and ejection of the ice therefrom. The motor 45 is energized by a switch 80 which is operated by the plunger 85 of a thermally sensitive device 88, the latter containing a liquid having approximately the same freezing rate as water and being insulated to ensure that the switch 80 is not operated until the water in the tray 11 is completely frozen. Switch 80 comprises a movable contact 82 (Fig. 2) and fixed contacts 83 and 84, movement of plunger 85 to its extreme retracted position being adapted to move contact 82 to engage contact 84, thus energizing the motor 45 and a heater 104. The latter heats the device 88 to cause plunger 85 to move towards its extended position. Shortly after the ice has been ejected from tray 11 a cam 111 mounted on shaft 48 causes a cam follower 110 to move a movable contact 94 of a switch 81 from contact 98 to contact 99 (Fig. 2), thus de-energizing motor 45 which remains in this state until plunger 85 has moved to its extended position and contact 82 of switch 80 is moved to contact 83. Further rotation of cam 111 causes follower 110 to move a further contact 93 of switch 81 to a contact 95 to energize a solenoid 96 which opens a valve (not shown) delivering water to the mould. Contacts 93 and 94 return to contacts 102 and 98 respectively to de-energize solenoid 96 and motor 45 after a further pre-determined amount of rotation of shaft 48, the cycle being initiated when plunger 85 moves contact 82 to contact 84. An arm 63 having its ends 64 and 65 journalled in supports 20 and 21 is provided to interrupt the cycle when the ice in a collecting bin beneath the ice-tray is above a pre-determined level. A switch 60 is mounted in an arm 66 secured to the end 64 of arm 63 and is normally urged into contact with a lever 69 which is pivotally mounted on arm 66 and has one end 70 in engagement with a cam 72 on shaft 48. The cam 72 is so shaped as to sweep arm 63 over the collecting bin on rotation of shaft 48 and to pivot lever 69 out of engagement with switch 60 when the latter is prevented from moving by engagement of arm 63 with ice in the collecting bin. The consequent opening of switch 60 de-energizes motor 45 (see Fig. 2).