| 摘要 |
<p>1371262 Injection moulding machines H J DRAZICK 24 Feb 1972 [25 Feb 1971] 8631/72 Heading B5A Injection moulding apparatus comprises upper and lower die plates 32, 18 and at least one die cavity 36 therein, a first material feed passage 50 in one of the die plates, a second passage 66 between the first passage and the die cavity, the first passage 50 intersecting the second passage 66, and valve means 76 in the second passage controlling an orifice 70 leading into the cavity 36 in response to a pressure differential the valve means including a bore and heating means 84 disposed within the bore to maintain the moulding material in a fluid condition. The pressure of material injected through an orifice 48 and passages 50, 66 opens the valve 76, and when the injection pressure is reduced the valve 76 is closed again by a spring 82. The valve 76 includes a needle tip portion 104 which may extend a minimal distance into the cavity 36. Electric heaters 60 and 84 are provided in the passage 50 and within the valve 76 respectively. Modifications.-Figure 1A (not shown) shows a modified head portion of the valve member (78a) and closure plug (74a) incorporating a plurality of dished spring members (87). Instead of being arranged vertically, the valve assembly 66-76 may be mounted at an angle to the vertical (Fig. 5, not shown).</p> |
