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US 2021/0245397 A1Published application
Plasticating apparatus screw having grooves of varying angles and depths
AssigneeDavis-Standard, LLC
InventorJohn P. Christiano
Life of this patent
Estimating the term…
Abstract
A screw for a plasticating apparatus has one or more helical flights. A portion of the screw has a plurality of advancing grooves arranged in a noncontinuous helix cut in the screw. The advancing grooves are dimensioned to receive material therein as the material is conveyed through the barrel. The screw has a plurality of noncontinuous cross-cut grooves traversing one or more of the advancing grooves. The cross-cut grooves have a second helix angle greater than the first helix angle and less than ninety degrees; and/or one or more of the cross-cut grooves have a third helix angle of about ninety degrees.
Claims18
A screw for a plasticating apparatus, the screw comprising:
- a longitudinal axis, the screw being rotatably supportable in a barrel for rotation about the longitudinal axis, the screw having a core and at least one helical flight extending along a length of the screw, the helical flight extending in a first threaded direction and defining a first helical path of a first helix angle measured relative to a reference line perpendicular to the longitudinal axis, the first helix angle being less than ninety degrees;
- the helical flight defining a helical channel;
- and
- a longitudinal portion of the screw having a plurality of advancing grooves with each having at least one closed-end, the plurality of advancing grooves being arranged in a noncontinuous helix cut in the screw core in the helical channel of the screw, each of the plurality of advancing grooves forming a second helical path in the helical channel and being arranged entirely between adjacent helical flights and extending substantially parallel to the helical flights, and the plurality of advancing grooves being dimensioned to receive material therein as the material is conveyed forward through the helical channel;
- the longitudinal portion further having a plurality of noncontinuous cross-cut grooves traversing at least one advancing groove;
- the plurality of cross-cut grooves comprising:
- at least one first cross-cut groove being oriented in the first threaded direction common to that of the helical flight and having a second helix angle measured relative to the reference line perpendicular to the longitudinal axis, wherein each cross-cut groove passes through the helical flight not more than two times so that the material can back flow and recirculate within the longitudinal portion, and the second helix angle is less than ninety degrees;
- and
- at least one second cross-cut groove having a third helix angle measured relative to the reference line perpendicular to the longitudinal axis,
- wherein the first helix angle, the second helix angle, and the third helix angle are different.
7 more elements
A screw for a plasticating apparatus, the screw comprising:
- a longitudinal axis, the screw being rotatably supportable in a barrel for rotation about the longitudinal axis, the screw having a core and at least one helical flight extending along a length of the screw, the helical flight extending in a first threaded direction and defining a first helical path of a first helix angle measured relative to a reference line perpendicular to the longitudinal axis, the first helix angle being less than ninety degrees;
- the helical flight defining a helical channel;
- and
- a longitudinal portion of the screw having a plurality of advancing grooves with each having at least one closed-end, the plurality of advancing grooves being arranged in a noncontinuous helix cut in the screw core in the helical channel of the screw, each of the plurality of advancing grooves forming a second helical path in the helical channel and being arranged entirely between adjacent helical flights and extending substantially parallel to the helical flights, and the plurality of advancing grooves being dimensioned to receive material therein as the material is conveyed forward through the helical channel;
- the longitudinal portion further having a plurality of noncontinuous cross-cut grooves traversing at least one advancing groove;
- the plurality of cross-cut grooves comprising:
- at least one first cross-cut groove being oriented in the first threaded direction common to that of the helical flight and having a second helix angle measured relative to the reference line perpendicular to the longitudinal axis, wherein each cross-cut groove passes through the helical flight not more than two times so that the material can back flow and recirculate within the longitudinal portion, and the second helix angle is less than ninety degrees;
- and
- at least one second cross-cut groove having a third helix angle measured relative to the reference line perpendicular to the longitudinal axis,
- wherein at least two of the first helix angle, the second helix angle, and the third helix angle are different.
7 more elements
Dependencies are inferred from the claim text.