US4144173A — Device for skimming material floating on a liquid

Claim 1

Independent Claim 317 words

A raking device for discharging floating material supernatant on a liquid contained in a basin by pushing the floating material along the surface of the liquid toward an overflow weir connected to one end wall, said raking device comprising in combination: a basin having side walls and end walls, the upper portions of said walls extending above the supernatant layer, said basin further having a weir including an inclined surface extending into the supernatant layer; a first frame positioned between the upper portions of the side walls; a plurality of blades attached to said first frame and spaced in the direction of pushing toward the weir to form a first rake assembly, each blade having a pushing surface extending substantially transversely to said frame; first suspension means connecting said first frame to walls of said basin for movement with respect to said basin in a first direction substantially parallel to the pushing direction, and in a second direction substantially transversely to said first direction; first driving means connected to said frame to reciprocate it in the first direction, the stroke length of the reciprocating movement being a fraction of the length of said basin in the first direction, and to reciprocate said first frame in the second direction between a first position and a second position which are vertically spaced so that the blades, in the first position, extend into said supernatant layer, and, in the second position, are completely retracted from said supernatant layer, the reciprocating movements in said first direction and said second direction being correlated by said first driving means so that each blade describes a closed-loop trajectory, moving from the second position to the first position in a direction substantially parallel to the pushing surface of each blade and moving substantially parallel to said supernatant layer while in the first position, the trajectories of the different blades being staggered in the first direction.

Claim 2

Dependent Claim 317 words

A raking device for discharging floating material supernatant on a liquid contained in a basin by pushing the floating material along the surface of the liquid toward an overflow weir connected to one end wall, said raking device comprising in combination: a basin having side walls and end walls, the upper portions of said walls extending above the supernatant layer, said basin further having a weir including an inclined surface extending into the supernatant layer; a first frame positioned between the upper portions of the side walls; a plurality of blades attached to said first frame and spaced in the direction of pushing toward the weir to form a first rake assembly, each blade having a pushing surface extending substantially transversely to said frame; first suspension means connecting said first frame to walls of said basin for movement with respect to said basin in a first direction substantially parallel to the pushing direction, and in a second direction substantially transversely to said first direction; first driving means connected to said frame to reciprocate it in the first direction, the stroke length of the reciprocating movement being a fraction of the length of said basin in the first direction, and to reciprocate said first frame in the second direction between a first position and a second position which are vertically spaced so that the blades, in the first position, extend into said supernatant layer, and, in the second position, are completely retracted from said supernatant layer, the reciprocating movements in said first direction and said second direction being correlated by said first driving means so that each blade describes a closed-loop trajectory, moving from the second position to the first position in a direction substantially parallel to the pushing surface of each blade and moving substantially parallel to said supernatant layer while in the first position, the trajectories of the different blades being staggered in the first direction.

Claim 3

Dependent Claim 55 words

The raking device of claim 1 further comprising: carrier means driven by said first driving means in the first direction with respect to said basin, said suspension means interconnecting said first frame and said carrier means so as to guide the movement of said first frame in the second direction relative to said carrier means.

Claim 4

Dependent Claim 48 words

The raking device of claim 2, in which said first suspension means further comprise: at least two pairs of guiding arms which are pivotally connected to said first frame and to said carrier means, the arms of each pair being separated from one another in the first direction.

Claim 5

Dependent Claim 141 words

The raking device of claim 2 wherein said first driving means further comprise: first cylinder means connected to said carrier means for reciprocating it in the first direction; second cylinder means connected to said carrier means and to said first frame for reciprocating said first frame relative to said carrier means; a source of driving medium connected to said first cylinder means and said second cylinder means for applying to them a controlled flow of the driving medium; and, control means associated with said first cylinder means with said second cylinder means and with said source of driving medium, and controlling the flow of the driving medium to said first and second cylinder means so as to produce a coordinated succession of movements of said first frame in the first and second directions causing each blade to describe the closed-loop trajectory.

Claim 6

Dependent Claim 79 words

The raking device of claim 2 wherein said driving means further comprise: first reciprocating means for reciprocating said carrier means in the first direction; guiding means fixed to said basin; and, follower means connected to said first frame and cooperating with said guiding means during motion of said carrier means in the first direction to produce a reciprocating movement of said first frame in the second direction coordinated with the movement of said carrier means in the first direction.

Claim 7

Dependent Claim 116 words

The raking device of claim 1, wherein said first frame is movable in the first direction so that the trajectory of at least the extreme blade nearest to the overflow weir sweeps over a portion of the inclined surface of said weir, and wherein the correlation of the movements in the first and second directions provided by said first driving means is such that the movement of said first frame in the second direction is started near the end of the movement of said first frame in the first direction towards the overflow weir so as to guide the free extremity of at least said extreme blade substantially parallel to the inclined surface of said weir.

Claim 8

Dependent Claim 279 words

The raking device of claim 1 further comprising: a second rake assembly including a second frame and at least one blade, and being spaced from said first rake assembly in the first direction; second suspension means connecting said second frame to said basin walls to position said second frame generally above the inclined surface of said overflow weir, and allowing said second frame to be moved in a third direction substantially parallel to said inclined surface, and in a fourth direction substantially transversely to the third direction, second driving means connected to said second frame to reciprocate it in the third direction, and also to reciprocate it in the fourth direction between a third position and a fourth position which are vertically spaced so that, in the third position, the free extremity of each blade is kept at a small distance from said inclined surface while extending into a part of the supernatant layer being pushed along said inclined surface over said weir, and so that, in the fourth position, the free extremity of each blade is retracted from said layer, said third and fourth reciprocating movements being correlated by said second driving means so that each blade describes a closed-loop trajectory, the movement from the fourth position to the third position being substantially parallel to the pushing surface of each blade, and the operation of said second driving means being correlated with the operation of said first driving means in such a manner that the part of the supernatant layer being pushed onward by the blades of said first frame is taken over by the blades of said second frame so as to be pushed over the weir.

Claim 9

Dependent Claim 35 words

The raking device of claim 7 wherein said second driving means further comprise a drive crank connected to said second frame for driving said second rake assembly in a reciprocating motion in the fourth direction.

Claim 10

Dependent Claim 19 words

The raking device of claim 7, wherein said first and said second frames are interconnected at their adjacent ends.

Claim 11

Dependent Claim 52 words

The raking device of claim 7, further comprising: an upright guiding frame, a first pivot means connecting said guiding frame to the basin for movement substantially in the third direction; and, second pivot means connecting said second frame to said guiding frame for movement of said second frame in the fourth direction.

Claim 12

Dependent Claim 41 words

The raking device of claim 10, wherein said second driving means further comprise third cylinder means for moving said guiding frame with respect to the basin, and fourth cylinder means for moving said second frame with respect to said guiding frame.

Claim 13

Dependent Claim 35 words

The raking device of claim 1 wherein said first driving means further comprise a drive crank connected to said first frame for driving said first rake assembly in a reciprocating motion in the second direction.

Claim 14

Dependent Claim 43 words

The device of claim 1, in which said first suspension means further comprise a guiding bar assembly including a plurality of bars pivotally interconnected to form a multiple shear, the blades being connected to pivot points along one side of said multiple shear.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1982-03-12	1982-09-11	1983-03-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1986-03-12	1986-09-11	1987-03-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1990-03-12	1990-09-11	1991-03-13	$7700.00	Window Closed / Lapsed

Device for skimming material floating on a liquid

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