Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
211 words
Blow-moulding apparatus for the manufacture of hollow bodies from a thermoplastic material, said apparatus comprising, in combination: (a) a screw-extruder for forming a parison; (b) a receiving station into which said parison is extruded; (c) a mould release station spaced from said receiving station; (d) a blow-mould consisting of at least two openable parts, said blow-mould being movable to and fro between said receiving station and said mould release station, the open blow-mould encompassing the parison in the receiving station; (e) means for detecting when the length of the parison extruded reaches a given length corresponding to the length of the blow-mould; (f) control means operable only by said detecting means when the mould is at said receiving station, effective to close the mould parts on the parison; (g) time-dependent open-loop control means effective to control the movement of the blow-mould, whereby it is in the open position in said receiving station before the length of said parison reaches said given length; and (h) means for controlling the speed of the screw of the screw-extruder with a change of speed proportional to a change of time outside a predetermined range of times at which the parison reaches said given length, whereby the time for each mould cycle remains within said range.
Claim 2
Dependent Claim
211 words
Blow-moulding apparatus for the manufacture of hollow bodies from a thermoplastic material, said apparatus comprising, in combination: (a) a screw-extruder for forming a parison; (b) a receiving station into which said parison is extruded; (c) a mould release station spaced from said receiving station; (d) a blow-mould consisting of at least two openable parts, said blow-mould being movable to and fro between said receiving station and said mould release station, the open blow-mould encompassing the parison in the receiving station; (e) means for detecting when the length of the parison extruded reaches a given length corresponding to the length of the blow-mould; (f) control means operable only by said detecting means when the mould is at said receiving station, effective to close the mould parts on the parison; (g) time-dependent open-loop control means effective to control the movement of the blow-mould, whereby it is in the open position in said receiving station before the length of said parison reaches said given length; and (h) means for controlling the speed of the screw of the screw-extruder with a change of speed proportional to a change of time outside a predetermined range of times at which the parison reaches said given length, whereby the time for each mould cycle remains within said range.
Claim 3
Dependent Claim
31 words
Blow-moulding apparatus as claimed in claim 1, wherein the parts of the blow-mould, in their initial position on arrival at the receiving station, are separated by less than their maximum spacing.
Claim 4
Dependent Claim
47 words
Blow-moulding apparatus as claimed in claim 1, wherein the control means are such that the cycle of movements of the parts of the apparatus are at least predominantly time-controlled, and the waiting time of the blow-mould in the receiving station is planned into the cycle of movements.
Claim 5
Dependent Claim
31 words
Blow-moulding apparatus as claimed in claim 1, wherein the means for detecting the length of the parison is mounted on the blow-mould on the side thereof remote from the screw extruder.
Claim 6
Dependent Claim
33 words
Blow-moulding apparatus as claimed in claim 4, wherein the detecting means comprise means for producing a beam of light transverse to the direction of extrusion of the screw-extruder and a co-operating photo-electric cell.