| 摘要 |
The push rod (19) which causes the secure closing or opening of the liquid shut-off valve (5), and which also causes the closing or opening of the gas circuit leading to the level tube (6), is connected structurally so as to form a single piece with the stem (28) of a fluid pressure actuator (A), preferably of the pneumatic type, and the body (26) of this actuator is fixed, for example by screwing or by some other method so as to be removable, with sealing means (25), to the upper end of the barrel or body (8) of the filling head, in such a way that it can be easily removed and fitted to facilitate any necessary maintenance, the area of connection between the pneumatic actuator and the said barrel (8) being isolated from the outside by highly reliable sealing means which comprise, in addition to static seals and lateral seals, a bellows (31) of any fluid-tight, flexible and pressure-resistant material which surrounds the extended part of the stem (28) of the actuator (A) and which has one of its ends connected with a seal to the lower part or base (126) of the body of the said actuator and has its other end connected to the lower end of the said stem, in the area in which this end is connected to the push rod (19) which actuates the filling head, the whole being designed in such a way that, when the actuator (A) is removed from the filling head, it remains attached to the push rod (19), whose sealing gasket (119) can also be periodically replaced. <IMAGE> |
