| 摘要 |
A filter and pressure relief assembly for an adhesive supply unit comprises an adhesive supply hopper (12), a filter basket (20) disposed within a cavity (18) defined within a filter block (16), and a filter plug (22) for retaining the filter basket (20) within the filter block (16). Inlet port (32) provides an infeed of adhesive from the hopper (12), an outlet port (36) leads to an applicator, and a return port (54) and conduit (56) return adhesive back to the hopper (12). The filter plug (22) contains a pressure relief valve (44) which opens and connects the inlet port (32) to the return port (54) and conduit (56) so as to return adhesive to the hopper (12) under over-pressurized conditions, and a pair of O-ring members (100, 102) for respectively engaging small and large diameter regions (104, 106) of the cavity (18). A slide plate (66) is movable between three positions (82, 80, 78) and is operatively engaged with the filter plug (22) so as to respectively retain the filter plug (22) at a full retention and a partial retention position within the filter block (16), or permit release of the filter plug (22) and the filter basket (20) from the filter block (16). When the filter basket (20) is to be removed from the filter block (16), the slide plate (66) is moved to its second position (80) at which the filter plug (22) moves upwardly within the filter block (16) such that the lower O-ring member (102) disengages the small diameter region (104) of the cavity (18) so as to relieve the pressure within the system and permit adhesive to return to the hopper (12), the upper O-ring member (100) maintaining the sealing of the system. The slide plate (66) is then moved to the release position (78) so as to permit the filter plug (22) and the filter basket (20) to be removed safely from the filter block (16) without any forceful discharge of adhesive from the system.
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