Fish escalator

Claim 2

In combination with a dam including upstream and downstream sides and with which high and low water levels, respectively, are operatively associated, means establishing first and second closed communication passages between a high elevation on the upstream side of said dam and a lower elevation on the downstream side of said dam and including adjacent corresponding upper and lower ends, said passages including means operative to convey water and objects suspended therein through said first passage at a first rate from said upstream side of said dam to said downstream side and through said second passage at a second lower rate from said downstream side to said upstream side, said first passage being of greater cross-sectional area than said second passage, said means operative to convey water being wholly gravity operated and comprising a plurality of spaced interconnected imperforate partitions connected together for simultaneous movement in train fashion and supported for guided downward movement through said first passage and subsequent upward movement through said second passage, said partitions including peripheral edges in fluid seal foRming engagement with the walls of said passages, whereby the conveying of water and fish past said dam in both directions may be effected without the use of an outside power source, said passages establishing closed communication with the upstream side of said dam below said high water level.

Claim 3

In combination with a dam including upstream and downstream sides, a fish escalator comprising means defining an elongated passage including an inlet end disposed at a low elevation on the downstream side of the dam and an outlet end disposed at a higher elevation on the upstream side of the dam, a plurality of partitions supported from said passage defining means for movement through said passage in substantially constant spaced relation relative to each other and in at least reasonably good fluid sealing relation with the surfaces defining said passage, and means connected to said partitions for causing said partitions to move into the inlet end of said passage, through the latter and out of the outlet end of said passage, said means defining said passage including means defining opposite side grooves extending along the opening into said passage, said means causing said partitions to move through said passage comprising flexible tension members extending through said lengthwise shiftable in said grooves, said partitions including opposite side portions thereof joined to corresponding portions of said tension members, said flexible tension members comprising corresponding reaches of a pair of endless flexible tension members, said fish escalator also including means defining a second passage generally paralleling the first-mentioned passage and through which said partitions are lengthwise movable, said second passage also including opposite side grooves in which second reaches of said endless flexible tension members are disposed, said means defining said passages including pairs of guide wheels at the corresponding ends of said passages and about which said endless tension members are trained, the ends of said second passage corresponding to the inlet and outlet ends of said first passage opening outwardly of said downstream and upstream sides of said dam, said passages being of substantially the same width, the transverse dimension of said first passage measured at 90* relative to the width thereof being slightly less than the corresponding transverse dimension of the second passage, said partition members being slightly inclined relative to transverse planes extending through said passages normal to the longitudinal centerlines thereof, the partitions in said first-mentioned passage being inclined more greatly relative to the corresponding transverse planes than the partitions in said second mentioned passage.

Claim 4

In combination with a dam including upstream and downstream sides, a fish escalator comprising means defining an elongated passage including an inlet end disposed at a low elevation on the downstream side of the dam and an outlet end disposed at a higher elevation on the upstream side of the dam, a plurality of partitions supported from said passage defining means for movement through said passage in substantially constant spaced relation relative to each other and in at least reasonably good fluid sealing relation with the surfaces defining said passage, and means connected to said partitions for causing said partitions to move into the inlet end of said passage, through the latter and out of the outlet end of said passage, said means defining said passage including means defining opposite side grooves extending along the opening into said passage, said means causing said partitions to move through said passage comprising flexible tension members extending through said lengthwise shiftable in said grooves, said partitions including opposite side portions thereof joined to corresponding portions of said tension members, said flexible tension members comprising corresponding reaches of a pair of endless flexible tension members, said fish escalator also including means defining a second passage generally paralleling the first-mentioned passage and through which said partitions are lengthwise movable, said second passage also including opposite side grooves in which second reaches of said endless flexible tension members are disposed, said means defining said passages including pairs of guide wheels at the corresponding ends of said passages and about which said endless tension members are trained, the ends of said second passage corresponding to the inlet and outlet ends of said first passage opening outwardly of said downstream and upstream sides of said dam, said passages being of substantially the same width, the transverse dimension of said first passage measured at 90* relative to the width thereof being slightly less than the corresponding transverse dimension of the second passage, said partition members being slightly inclined relative to transverse planes extending through said passages normal to the longitudinal centerlines thereof, the partitions in said first-mentioned passage being inclined more greatly relative to the corresponding transverse planes than the partitions in said second mentioned passage.

Claim 5

The combination of claim 2 wherein the downstream ends of said passages open into an upwardly opening compartment defined by upstanding wall portions including at least one upper marginal edge portion disposed at an elevation approximately equal to the water level on the downstream side of said dam.

Claim 6

The combination of claim 3 wherein said upper marginal portion is elevated at least slightly after the water level on said downstream side of said dam.

Claim 7

The combination of claim 4 including average water levels on the upstream and downstream sides of said dam, the outlet end of said passage being disposed below the water level on said upstream side of said dam and said inlet end of said passage being disposed below the water level on the downstream side of said dam.

Claim 8

In combination with a dam including upstream and downstream sides, a fish escalator comprising means defining an elongated passage including an inlet end disposed at a low elevation on the downstream side of the dam and an outlet end disposed at a higher elevation on the upstream side of the dam, a plurality of partitions supported from said passage defining means for movement through said passage in substantially constant spaced relation relative to each other and in at least reasonably good fluid sealing relation with the surfaces defining said passage, and means connected to said partitions for causing said partitions to move into the inlet end of said passage, through the latter and out the outlet end of said passage, said means defining said passage including means defining opposite side grooves extending along and opening into said passage, said means causing said partitions to move through said passage comprising flexible tension members extending through and lengthwise shiftable in said grooves, said partitions including opposite side portions thereof joined to corresponding portions of said tension members, said flexible tension members comprising corresponding reaches of a pair of endless flexible tension members, said fish escalator also including means defining a second passage generally paralleling the first-mentioned passage and through which said partitions are lengthwise movable, said second passage also including opposite side grooves in which second reaches of said endless flexible tension members are disposed, said means defining said passages including pairs of guide wheels at the corresponding ends of said passages and about which said endless tension members are trained, the ends of said second passage corresponding to the inlet and outlet ends of said first passage opening outward of said downstream and upstream sides of said dam, said passages being of substantially the same width, the transverse dimension of said first passage measured at 90* relative to the width thereof being slightly less than the corresponding transverse dimension of the second passage, said partition members being slightly inclined relative to transverse planes extending through said passages normally to the longitudinal centerlines thereof, the partitions in said first-mentioned passage being inclined more greatly relative to the corresponding transverse planes than the partitions in said second-mentioned passage, means supporting said wheels from said passage-defining means for shifting at least one pair of said wheels relative to the other pair of said wheels in order to adjust the tension of said endless tension members.

Claim 9

In combination with a dam including upstream and downstream sides, a fish escalator comprising means defining an elongated passage including an inlet end disposed at a low elevation on the downstream side of the dam and an outlet end disposed at a higher elevation on the upstream side of the dam, a plurality of partitions supported from said passage defining means for movement through said passage in substantially constant spaced relation relative to each other and in at least reasonably good fluid sealing relation with the surfaces defining said passage, and means connected to said partitions for causing said partitions to move into the inlet end of said passage, through the latter and out the outlet end of said passage, said means defining said passage including means defining opposite side grooves extending along and opening into said passage, said means causing said partitions to move through said passage comprising flexible tension members extending through and lengthwise shiftable in said grooves, said partitions including opposite side portions thereof joined to corresponding portions of said tension members, said flexible tension members comprising corresponding reaches of a pair of endless flexible tension members, said fish escalator also including means defining a second passage generally paralleling the first-mentioned passage and through which said partitions are lengthwise movable, said second passage also including opposite side grooves in which second reaches of said endless flexible tension members are disposed, said means defining said passages including pairs of guide wheels at the corresponding ends of said passages and about which said endless tension members are trained, the ends of said second passage corresponding to the inlet and outlet ends of said first passage opening outward of said downstream and upstream sides of said dam, said passages being of substantially the same width, the transverse dimension of said first passage measured at 90* relative to the width thereof being slightly less than the corresponding transverse dimension of the second passage, said partition members being slightly inclined relative to transverse planes extending through said passages normally to the longitudinal centerlines thereof, the partitions in said first-mentioned passage being inclined more greatly relative to the corresponding transverse planes than the partitions in said second-mentioned passage, means supporting said wheels from said passage-defining means for shifting at least one pair of said wheels relative to the other pair of said wheels in order to adjust the tension of said endless tension members.