| 摘要 |
<p>700,984. Hydraulic machines. SHIPTON & CO., Ltd., E. Sept. 10, 1951 [Sept. 11, 1950], No. 22365/50. Class 69 (2). [Also in Groups V and XXIV] A machine for extruding plastic tubes and blowing the tubes in moulds to form hollow articles (see Group V) includes a hydraulic-system which opens and closes the moulds and performs other operations. Four moulds M are fed in turn with plastic material by a screw 1. Each mould is in two parts 54 which are closed by large hydraulic rams 56, 57 and opened by small hydraulic rams 56', 57<SP>1</SP>. A hydraulic pump 46 delivers pressure oil through line 47 to four valves 60 ... 63 and thence through lines 68 or 69, to rams 56, 57 or to rams 56<SP>1</SP>, 57<SP>1</SP> respectively. When pressure passes to rams 56, 57 a check valve 70 maintains the pressure to hold the mould parts firmly closed. When pressure passes to rams 56', 57<SP>1</SP> check valve 70 is released and allows exhaust of the large ram cylinders through line 71. Each mould has its own valve, and each valve controls four rams. There are four check valves 70, but only one is shown. The valves are operated one after another by cams 64 ... 67 on a rotary cam shaft 27. Cam shaft 27 is rotated intermittently, 90 degrees at a time, by a hydraulically-operated ratchet gear 40 (see Group XXIV), moved by hydraulic cylinders 44, 45. The supply of oil to these cylinders is via valve 48 and lines 51, 52. Valve 48 is controlled by a cam 49 driven from electric motor 4 via reduction gear 5 and adjustable gear train 50. The screw 1 is rotated by motor 4 through reduction gearing 5 and clutch 6. The position of the clutch is controlled by two cylinders 85, 86 fed with oil from valve 84 controlled by cam disc 82 on shaft 27. When one of the moulds is not being used a cam 83 is put in the appropriate place in the cam disc to operate valve 84 and cylinders 85, 86 to disengage the clutch for the period normally used to feed that mould.</p> |
