US 4,167,384 AGranted

Filter screen exchanging apparatus for plastic extruder

AssigneeThe Japan Steel Works, Ltd.

InventorsToru Shirato, Minoru Yoshida, Hideki Mizuguchi

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Abstract

A filter screen exchanging device having a pair of parallel slide plates 12 disposed in branched passages DK, EL of a plastic resin extruder 10. Each slide plate has a shouldered hole 14 on one side accommodating a breaker plate 15 having a plurality of flow nozzles 20, a filter screen 17, and a threaded screen cap 18 having a plurality of trapezoidal apertures therein. The other side of each slide plate is blind, and the plates are alternately transferred for screen and cap exchange by hydraulic cylinders 13. The extruder operation is thus continuous, the breaker plate is not exchanged with each screen and cap replacement, and the screen mounting arrangement is designed to minimize air entry and resin leakage during slide transfer.

Claims6

Dependent claims

A filter screen exchanging device for a plastic resin extruding apparatus having branched resin flow passages, comprising:

(a) a pair of elongated, generally planar slide plates arranged in parallel with each other and individually slidably disposed in associated resin flow passages transverse to the resin flow direction,
(b) a through-hole in one half of each slide plate, the other side of each slide plate being solid,
(c) an apertured breaker plate mounted in each through-hole,
(d) a filter screen disposed over each breaker plate on its upstream side,
(e) an apertured screen cap overlying each filter screen and removably secured in the respective through-hole to rigidly retain said filter screen in place, and
(f) means for selectively transferring each slide plate between a first postion whereat its filter screen is disposed in the associated resin flow passage and a second position whereat its filter screen is exposed for removal and replacement and its solid side blocks its associated resin flow passage.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/889,588Filed 23 Mar 1978
Priority: JP 52-14157228 Nov 1977
Granted: 11 Sep 1979
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

B29C 48/6912
Arrangements for replacing filters, e.g. with two parallel filters for alternate use: the filters being fitted on a single rectilinearly…
B29C 48/03
Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor:…
B29C 48/693
Filters or screens for the moulding material: substantially flat filters mounted at the end of an extruder screw perpendicular to the feed axis
B29C
Shaping or joining of plastics