| 摘要 |
1299762 Vacuum apparatus W R GRACE & CO 1 July 1970 [25 July 1969] 31956/70 Headings F1N and F1P (or F1D) [Also in Division B8] An apparatus for evacuating air from a product containing plastics bag during packaging, comprises a fixed suction tube 14 and a slide 30, 42 having a handle 34 around which is gathered the mouth of the bag, the handle 34 being moved downwardly when suction is to be applied through the tube to nozzle ports 74. The slide 30, 42 moves over the tube 14 and extends through a seal 38 into a cylinder 36 maintained under vacuum through a conduit 6. When the slide is moved downwardly against the action of a spring 41. radial ports in the slide align with elongated slots 67 in the tube 14 to communicate the vacuum in the cylinder 36 with the tube 14. Further downward movement of the slide 30, 42 results in the upper end 35 of the slide passing below radial ports 71 in the fixed tube 14 whereby air is evacuated downwardly through a passage 64 from a space below a universally jointed piston 90 in a cylinder 36. This evacuation causes the assembly 14, 30, 42, 36 &c to lift, thereby to stretch the mouth of the bag and facilitate sealing thereof. The apparatus is easily disassembled for cleaning, the end-cap of the cylinder 36 having a bayonet connection to the cylinder. |
