Twin screw extruder shafts, each driven by multiple gear sets, each with offset partial splines

Claim 2

In a driving arrangement for extruder screws, a motor driven shaft, at least another shaft arranged parallel to said shaft, and extruder screws connected to said shafts for working against each other; a plurality of gear means arranged on each of said shafts, separately, one next to the other, the plurality of gear means on one shaft meshing with those on the other shaft so as to drive the shafts in opposite directions while distributing the power over said plurality of gear means; and interlocking means for coupling the outer surfaces of the shafts with the inner surfaces of at least one pair of gear means meshing with each other; the interlocking means for each of said gear means extending over portions of said shafts which are substantially smaller than the corresponding effective width of the gear means, the interlocking means for one gear on one of said shafts being axially displaced with respect to the interlocking means of its mating gear on said other shaft.

Claim 3

Arrangement according to claim 1, wherein said interlocking means for couples the outer surfaces of the shafts with the inner surfaces of at least two pairs of gears means, the gears of each pair meshing with each other; the interlocking means for each of said gear means extending over portions of said shafts which are substantially smaller than the corresponding effective width of the gear means; the interlocking means for the gear means of one pair being axially displaced with respect to each other; and the interlocking means for the gear means of the other pair being axially so displaced with respect to each other so as to form a mirror-reflected image of the interlocking means of the first pair with respect to a common center arranged in the middle between said pairs of gear means.

Claim 4

Arrangement according to claim 2, wherein said gear means is additionally seated directly on said shafts at least at its ends.

Claim 5

Arrangement according to claim 2, wherein said plurality of gear means comprises at least two separately mounted gears having teeth meshing with corresponding teeth of the gears on the other of said shafts, whereby the power transfer between the shafts driving the extruder screws occurs at least through said helical teeth driving gears, said helical teeth driving gears comprising at least said one meshing pair.

Claim 6

Arrangement according to claim 1, wherein said plurality of gear means comprises at least two separately mounted gears having teeth meshing with corresponding teeth of the gears on the other of said shafts, whereby the power transfer between the shafts driving the extruder screws occurs at least through said helical teeth driving gears, said helical teeth driving gears comprising at least said one meshing pair.

Claim 7

Arrangement according to claim 1, wherein said gear means is additionally seated directly on said shafts at least at its ends.

Claim 8

In a driving arrangement, a pair of gears meshing with each other, each having a tooth width at least of the order of the magnitude of the pitch circle diameter, a pair of shafts supporting said gears and connected thereto, secure against turning through interlocks extending over merely a surface which is small as compared with the tooth width, at least the ends of each gear being also seated directly on the shaft, said interlocks being axially displaced on opposite sides of a common center line perpendicular to the shaft of said gear pair.

Claim 9

In a driving arrangement, a pair of gears meshing with each other, each having a tooth width at least of the order of the magnitude of the pitch circle diameter, a pair of shafts supporting said gears and connected thereto, secure against turning through interlocks extending over merely a surface which is small as compared with the tooth width, at least the ends of each gear being also seated directly on the shaft, said interlocks being axially displaced on opposite sides of a common center line perpendicular to the shaft of said gear pair.

Claim 10

In a driving arrangement for extruder screws, a motor driven shaft, at least another shaft arranged parallel to said shaft, and extruder screws connected to said shafts for working against each other; at least four gear means arranged on said shafts, separately, one next to the other, two of said four gear means on one shaft meshing with those on the other shaft so as to drive the shafts in opposite directions while distributing the power over said four gear means; interlocking means for coupling the outer surface of said shafts with the inner surface of said four gear means; the interlocking means for at least one of said gear means and for the gear means meshing with said one gear means extending over portions of said shafts which are substantially smaller than the corresponding effective width of said gear means; the remaining inner surface of said two gear means being supported at least on its ends directly on the outer surface of said shafts; the interlocking means on one of said shafts being axially displaced with respect to the interlocking means on said other shaft.

Claim 11

In a driving arrangement for extruder screws, a motor driven shaft, at least another shaft arranged parallel to said shaft, and extruder screws connected to said shafts for working against each other; at least four gear means arranged on said shafts, separately, one next to the other, two of said four gear means on one shaft meshing with those on the other shaft so as to drive the shafts in opposite directions while distributing the power over said four gear means; interlocking means for coupling the outer surface of said shafts with the inner surface of said four gear means; the interlocking means for at least one of said gear means and for the gear means meshing with said one gear means extending over portions of said shafts which are substantially smaller than the corresponding effective width of said gear means; the remaining inner surface of said two gear means being supported at least on its ends directly on the outer surface of said shafts; the interlocking means on one of said shafts being axially displaced with respect to the interlocking means on said other shaft.