| 摘要 |
<p>PURPOSE: To make possible an accurate positioning of a plate and prevent frost from being formed on moving portions, by vertically suspending each jack element with respect to the frame of a freezer, connecting it to a motor by a screw and a nut, and allowing a tube and a tubular body to communicate with a closed expansion reservoir of air at the upper portions thereof to define an oil-filled closed space. CONSTITUTION: A stack of plates 26 are placed on a thick plate 28 supported by four jacks 30 suspended from the ceiling of a chamber. To charge products to be frozen onto the stacked plates, the jacks 30 move the plates to the height of a conveyer 24, and a pusher bar 32 introduces the products into the chamber by row through an opening 20. The interior of a pipe 48 and a space 68 are filled with oil for securing smooth movement of screws. A hollow and hermetic tubular casing 18 serves as a tank, so that external air with moisture does not enter a tubular body 54 also when the jacks are extended so that oil is at low level. The upper end of screw of each jack is connected to a motor speed reducer, that is, a brake 66 which rotates the screw in two directions to vertically move and hold the plate at a desired height.</p> |
