Mechanism for operating thickener rake arms

Claim 2

In a thickener of the type including in combination a cylindrical tank having a bottom sloping toward the center and a peripheral wall, a receiver for liquid overflow at the wall and a central sludge discharge outlet, means for supplying liquid containing suspended material to the central portion of the tank, a rake arm carrying a plurality of sediment rakes mounted for rotation in the tank and extending radially from the central portion of the tank to its periphery, and traction means connected to the outer end of the rake arm for pulling it around in and for effecting its rotation in the tank, the improvement wherein the traction means comprises a. a drive cable extending around the periphery of the tank and rotatably movable in a path around the periphery of the tank, b. a plurality of spaced cable carriers distributed around the tank supporting said drive cable and mounted for movement in spaced relation in a direction around the periphery of the tank and for movement by the drive cable along said path, c. means on each cable carrier for receiving, supporting and holding the drive cable, d. pull means connecting the outer end of the rake arm to one of said cable carries, e. said drive cable extending around the cable carriers and engaging the supporting means of all of said cable carriers, and f. means for continuously pulling the drive cable in a direction around tHe tank along said path to advance the cable carriers around the tank, effect rotation of the rake arm in the tank and movement of settled material toward the sludge discharge outlet.

Claim 3

A thickener as claimed in claim 1, including an endless track on which said cable carriers are mounted, each cable carrier including a frame mounted on a free-running wheel operable along the track, the receiving and holding means for the drive cable and means for holding the pull means for the rake arm being located on said frame of said one carrier.

Claim 4

A thickener as claimed in claim 2, wherein the drive cable and the receiving means therefor are located on the outside and the means for holding the rake arm pull means is located on the inside of the cable carrier frame.

Claim 5

A thickener as claimed in claim 2, wherein the means on the frame for receiving and holding the drive cable comprises a bracket on the outside lower portion of the frame adapted to receive a plurality of runs of the drive cable.

Claim 6

A thickener as claimed in claim 2, wherein the endless track comprises a pair of spaced trackways and the cable carrier comprises a pair of spaced wheels or rollers respectively operable on the trackways and mounted for free rotation on a common axle comprising a part of the carrier frame.

Claim 7

A thickener as claimed in claim 5, wherein the axle is a dead shaft and the wheels or rollers are loose, and wherein the means for holding the rake arm pull means is on the inner end of the axle and the means for receiving and holding the drive cable is a bracket on the outer end of the axle.

Claim 8

A thickener as claimed in claim 1, wherein the drive cable is an endless cable and the pulling means for the drive cable is located outside and in spaced relation to the periphery of the tank, means for diverting a portion of the drive cable from a cable carrier advancing toward the position of the drive cable pulling means, and means for directing a portion of the moving cable from the drive cable pulling means to a cable carrier moving away from the position of the drive cable pulling means.

Claim 9

A thickener as claimed in claim 7, wherein the drive cable includes a complete wrap around all the cable carriers in addition to the portions of the endless drive cable moving to and from the drive cable pulling means.

Claim 10

In a thickener of the type including in combination a cylindrical tank having a bottom sloping toward the center and a peripheral wall, a receiver for liquid overflow at the wall and a central sludge discharge outlet, means for supplying liquid containing suspended material to the central portion of the tank, a rake arm carrying a plurality of sediment rakes mounted for rotation in the tank and extending radially from the central portion of the tank to its periphery, and traction means connected to the outer end of the rake arm for pulling it around in and for effecting its rotation in the tank, the improvement wherein the traction means comprises a. a drive cable extending around the periphery of the tank and rotatably movable in a path around the periphery of the tank, b. a plurality of spaced cable carriers distributed around the tank supporting said drive cable and mounted for movement in spaced relation in a direction around the periphery of the tank and for movement by the drive cable along said path, c. means on each cable carrier for receiving, supporting and holding the drive cable, d. pull means connecting the outer end of the rake arm to one of said cable carriers, e. said drive cable extending around the cable carriers and engaging the supporting means of all of said cable carriers, f. an electric drive motor outside the tank for continuously pulling the drive cable in a direction around the tank along said path to advance the cable carriers around the tank, effect rotation of the rake arm in the tank and movement of settled material toward the sludge discharge outlet, g. an upright column in the center of the tank, a first sleeve supported On the column near the bottom of the tank for slidable up and down movement, said sleeve having an outside cylindrical bearing surface, a second sleeve bearing around, supported by and rotatable on the bearing surface of the first sleeve, means on the outside of said second sleeve for connecting the inner end of the rake arm thereto for up and down pivoting action, a cable operated by a second electric motor connected to the first sleeve for lifting both sleeves and the inner end portion of the rake arm, and h. means responsive to an overload on the drive motor for actuating the second motor to lift the inner end portion of the rake arm above the bottom sediment thereby avoiding an excessive overload of sediment on the rake arm.

Claim 11

In a thickener of the type including in combination a cylindrical tank having a bottom sloping toward the center and a peripheral wall, a receiver for liquid overflow at the wall and a central sludge discharge outlet, means for supplying liquid containing suspended material to the central portion of the tank, a rake arm carrying a plurality of sediment rakes mounted for rotation in the tank and extending radially from the central portion of the tank to its periphery, and traction means connected to the outer end of the rake arm for pulling it around in and for effecting its rotation in the tank, the improvement wherein the traction means comprises a. a drive cable extending around the periphery of the tank and rotatably movable in a path around the periphery of the tank, b. a plurality of spaced cable carriers distributed around the tank supporting said drive cable and mounted for movement in spaced relation in a direction around the periphery of the tank and for movement by the drive cable along said path, c. means on each cable carrier for receiving, supporting and holding the drive cable, d. pull means connecting the outer end of the rake arm to one of said cable carriers, e. said drive cable extending around the cable carriers and engaging the supporting means of all of said cable carriers, f. an electric drive motor outside the tank for continuously pulling the drive cable in a direction around the tank along said path to advance the cable carriers around the tank, effect rotation of the rake arm in the tank and movement of settled material toward the sludge discharge outlet, g. an upright column in the center of the tank, a first sleeve supported On the column near the bottom of the tank for slidable up and down movement, said sleeve having an outside cylindrical bearing surface, a second sleeve bearing around, supported by and rotatable on the bearing surface of the first sleeve, means on the outside of said second sleeve for connecting the inner end of the rake arm thereto for up and down pivoting action, a cable operated by a second electric motor connected to the first sleeve for lifting both sleeves and the inner end portion of the rake arm, and h. means responsive to an overload on the drive motor for actuating the second motor to lift the inner end portion of the rake arm above the bottom sediment thereby avoiding an excessive overload of sediment on the rake arm.