Automatic self-cleaning strainers

Claim 2

An automatic self-cleaning strainer comprising: a housing having inlet and outlet means, strainer drum means supported in said housing and having straining media in the periphery thereof, said drum means being so arranged that liquid entering the inlet means flows through said media to the outlet means; backwash shoe means arranged within said housing and normally engaged against that surface of said drum means which is expOsed to the inlet liquid and into which strained liquid backwashes through a selected area of said drum means to flush solids therefrom; indexing means for intermittently effecting relative rotation between said shoe and drum means in increments of arc about the axis of the drum means and effecting radial separation between the shoe and drum means during the incremental relative rotation therebetween and reestablishing engagement of the shoe means with the surface of the drum means when such incremental relative rotation has stopped.

Claim 3

The automatic self-cleaning strainer as set forth in claim 1 wherein said straining media include individual strainer elements carried by said drum means; and said indexing means being indexed with respect to the location of straining elements in the drum means and the dimensions of said backwash shoe means being such that only the full areas of said strainer elements register with the shoe means any time the shoe means is engaged with the drum means.

Claim 4

The automatic self-cleaning strainer as set forth in claim 1 wherein the interior of said drum means communicates with said inlet means and the exterior of said drum means communicates with said outlet means; said backwash shoe means is arranged to engage the interior surface of said drum means.

Claim 5

The automatic self-cleaning strainer as set forth in claim 1 wherein said drum means is fixed to said housing; and said backwash shoe means is rotatable with respect to said drum means.

Claim 6

The automatic self-cleaning strainer as set forth in claim 1 wherein said indexing means includes locking means for securing said backwash shoe means in engagement with said drum means between incremental relative rotation therebetween.

Claim 7

An automatic self-cleaning strainer, comprising: a hollow housing having liquid inlet and outlet means; strainer drum means supported in said housing and having straining media secure in openings extending therethrough, the interior of said drum means communicating with said inlet means and the exterior of said drum means communicating with said outlet means; backwash shoe means arranged within said housing and normally sealably engaging an interior portion of said drum means and covering a section of straining media for receiving backwash liquid flowing through such section of media from the exterior of said drum means and for discharging the backwash liquid from said housing; and indexing means supported by said housing and fixed to said shoe means for intermittently positioning said shoe means about the inner periphery of said drum means and effecting separation of the shoe means from the drum means during the repositioning thereof about said drum means and reestablishing engagement of the shoe means with the drum means when such repositioning is completed.

Claim 8

An automatic self-cleaning strainer, comprising: a hollow housing having liquid inlet and outlet means; strainer drum means supported in said housing and having straining media secure in openings extending therethrough, the interior of said drum means communicating with said inlet means and the exterior of said drum means communicating with said outlet means; backwash shoe means arranged within said housing and normally sealably engaging an interior portion of said drum means and covering a section of straining media for receiving backwash liquid flowing through such section of media from the exterior of said drum means and for discharging the backwash liquid from said housing; and indexing means supported by said housing and fixed to said shoe means for intermittently positioning said shoe means about the inner periphery of said drum means and effecting separation of the shoe means from the drum means during the repositioning thereof about said drum means and reestablishing engagement of the shoe means with the drum means when such repositioning is completed.

Claim 9

The automatic self-cleaning strainer as set forth in claim 6 wherein said indexing means is so constructed and arranged as to reciprocate said shoe means into and out of engagement with said drum means and to rotate said shoe means between disengaged positions thereof with respect to said drum means.

Claim 10

The automatic self-cleaning strainer as set forth in claim 6 including pressure means for urging said shoe means into engagement with said drum means.

Claim 11

The automatic self-cleaning strainer as set forth in claim 6 wherein said indexing means includes a cam and cam follower operatively engaging each other for guiding said shoe means out of and into engagement with said drum means during repositioning of said shoe means about said drum means.

Claim 12

The automatic self-cleaning strainer as set forth in claim 6 wherein said openings in said drum means are arranged in a pattern of successive like sections; and wherein said shoe means is shaped such that an entire one of said sections is surrounded without any overlap of adjacent sections by said shoe means when same is in engagement with said drum means.

Claim 13

The automatic self-cleaning strainer as set forth in claim 10 incLuding aligning means operative with said indexing means for aligning said shoe means with a section of said openings.

Claim 14

The automatic self-cleaning strainer as set forth in claim 10 wherein said indexing means includes a cam and cam follower operatively engaging each other for guiding said shoe means from engagement with said drum means and surrounding a section of openings to disengagement from said drum means and then into engagement with said drum means to surround a next-successive section of openings.

Claim 15

An automatic self-cleaning strainer, comprising: a hollow housing having liquid inlet and outlet means; a truncated cone-shaped strainer drum means supported in said housing and having a plurality of straining media secured in circumferentially spaced openings extending therethrough, the interior of said drum means communicating with said inlet means and the exterior of said drum communicating with said outlet means; backwash shoe means arranged within said housing and sealably engaging an interior portion of said drum means and covering a section of straining media for receiving backwash liquid flowing through such section of media from the exterior of said drum means and for discharging the backwash liquid from said housing; and indexing means supported by said housing and fixed to said shoe means for selectively positioning said shoe means about the inner periphery of said drum means, said indexing means including cam and cam follower means operatively engaging each other for guiding said shoe means reciprocally into and out of engagement with said drum means and rotatably between disengaged positions of said shoe means.

Claim 16

An automatic self-cleaning strainer, comprising: a hollow housing having liquid inlet and outlet means; a truncated cone-shaped strainer drum means supported in said housing and having a plurality of straining media secured in circumferentially spaced openings extending therethrough, the interior of said drum means communicating with said inlet means and the exterior of said drum communicating with said outlet means; backwash shoe means arranged within said housing and sealably engaging an interior portion of said drum means and covering a section of straining media for receiving backwash liquid flowing through such section of media from the exterior of said drum means and for discharging the backwash liquid from said housing; and indexing means supported by said housing and fixed to said shoe means for selectively positioning said shoe means about the inner periphery of said drum means, said indexing means including cam and cam follower means operatively engaging each other for guiding said shoe means reciprocally into and out of engagement with said drum means and rotatably between disengaged positions of said shoe means.

Claim 17

The automatic self-cleaning strainer as set forth in claim 13 including pressure means for urging said shoe means into engagement with said drum means.

Claim 18

The automatic self-cleaning strainer as set forth in claim 13 wherein said openings in said drum means are arranged in a pattern of successive like sections; and wherein said shoe means is shaped such that an entire one of said sections is surrounded without any overlap of adjacent sections by said shoe means when same is in engagement with said drum means.

Claim 19

The automatic self-cleaning strainer as set forth in claim 15 wherein said cam and cam follower means are so constructed and arranged such that said shoe means is guided from engagement with said drum means reciprocally towards the wide end of the drum means and then rotatably into alignment with the next section of openings and then reciprocally into engagement with the drum means.

Claim 20

An automatic self-cleaning strainer, comprising: a hollow housing having liquid inlet and outlet means; a generally cylindrically shaped strainer drum means supported in said housing and having a plurality of straining media secured in circumferentially spaced openings extending therethrough, the interior of said drum means communicating with said inlet means and the exterior of said drum communicating with said outlet means; backwash shoe means arranged within said housing and sealably engaging an interior portion of said drum means and covering a section of straining media for receiving backwash liquid flowing through such section of media from the exterior of said drum means and for discharging the backwash liquid from said housing; said backwash shoe means including a front shoe having an outer end portion normally engaging the interior surface of said drum means and an inner end inclined toward the axis of the drum means, a rear shoe slidably engaging and secured to said front shoe along the inner end thereof, and a hollow tube coaxial with said drum means supporting said rear shoe and communicating with the interior of said rear shoe and further communicating with the exterior of said housing; first and second stop means supported at opposite ends, respectively, of said drum means for limiting the axial movement of said front shoe with respect to said drum means; indexing means suppoRted by said housing and fixed to said backwash shoe means for selectively positioning said shoe means about the inner periphery of said drum means, said indexing means operatively engaging said tube to move same reciprocally with respect to said drum means whereby said front shoe is stopped by said first stop means and said rear shoe continues to reciprocate to move said front shoe out of engagement with said drum means and then rotatably into a next successive position where said tube is then moved reciprocally in the opposite direction where said front shoe is stopped by said second stop means and said rear shoe continues to reciprocate to move said front shoe into engagement with said drum means.

Claim 21

An automatic self-cleaning strainer, comprising: a hollow housing having liquid inlet and outlet means; a generally cylindrically shaped strainer drum means supported in said housing and having a plurality of straining media secured in circumferentially spaced openings extending therethrough, the interior of said drum means communicating with said inlet means and the exterior of said drum communicating with said outlet means; backwash shoe means arranged within said housing and sealably engaging an interior portion of said drum means and covering a section of straining media for receiving backwash liquid flowing through such section of media from the exterior of said drum means and for discharging the backwash liquid from said housing; said backwash shoe means including a front shoe having an outer end portion normally engaging the interior surface of said drum means and an inner end inclined toward the axis of the drum means, a rear shoe slidably engaging and secured to said front shoe along the inner end thereof, and a hollow tube coaxial with said drum means supporting said rear shoe and communicating with the interior of said rear shoe and further communicating with the exterior of said housing; first and second stop means supported at opposite ends, respectively, of said drum means for limiting the axial movement of said front shoe with respect to said drum means; indexing means suppoRted by said housing and fixed to said backwash shoe means for selectively positioning said shoe means about the inner periphery of said drum means, said indexing means operatively engaging said tube to move same reciprocally with respect to said drum means whereby said front shoe is stopped by said first stop means and said rear shoe continues to reciprocate to move said front shoe out of engagement with said drum means and then rotatably into a next successive position where said tube is then moved reciprocally in the opposite direction where said front shoe is stopped by said second stop means and said rear shoe continues to reciprocate to move said front shoe into engagement with said drum means.

Claim 22

The automatic self-cleaning strainer as set forth in claim 17 including pressure means for urging said shoe means into and out of engagement with said drum means.

Claim 23

The automatic self-cleaning strainer as set forth in claim 17 wherein said openings in said drum means are arranged in a pattern of successive like sections; and wherein said front shoe is shaped such that an entire one of said sections is surrounded without any overlap of adjacent sections by said front shoe when same is in engagement with said drum means.

Claim 24

The automatic self-cleaning strainer as set forth in claim 17 wherein said first and second stop means include ring members fixed at opposite end portions of said drum means.