| 摘要 |
An applicator is described which is sealed to a very high degree against any ingress of air and is therefore suitable for use with adhesives which react strongly with air. The applicator comprises a housing (2, 3, 4) having a bore (6) terminating at one end in an outlet aperture (10), a plunger (13, 14, 15, 16, 17, 18, 20) received in said bore (6) and mounted for movement between an open (liquid application) position and a closed position, the rear end (13, 14) of the plunger projecting from the other end (2) of the housing, the plunger including a longitudinal bore (19) for supply of liquid to be applied, the plunger being provided with one or more ports (21) through which liquid may flow from the bore (19) of the plunger into the bore (6) of the housing so arranged that when the plunger is in the fully open position the bore (6) of the housing and the bore (19) of the plunger co-operate to provide a streamlined flow path, means (16, 23, 25) for moving the plunger between the closed position and the open position; and a seal (34, 35, 36) between plunger and housing to prevent ingress of air. The novel features are (a) that the seal is a liquid barrier seal (36) and (b) that in the closed position a forward end (20) of the plunger seals said housing outlet aperture (10) and in the open position the forward end (20) of the plunger (13, 14, 15, 16, 17, 18, 20) is retracted into the housing.
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