Intermittent irrigation system

Claim 2

An intermittent irrigation system, comprising: a. an emitter line including a plurality of spaced emitter openings, the cumulative area of the emitter openings being less than the capacity of the emitter line; b. control means for filling and draining of the emitter line to effect intermittent discharge of water from the emitter openings; c. and a timer for controlling the cycle between filling and draining the emitter line, thereby to predetermine the total volume of water delivered during an irrigation period.

Claim 3

An intermittent irrigation system as defined in claim 1, wherein: a. the emitter openings are spaced, positioned and of such relative size as needed to discharge essentially equal volumes of water from the emitter line during drainage.

Claim 4

An intermittent irrigation system as defined in claim 1 wherein the control means comprises: a. a pressure sensitive valve disposed at the entrance end of the emitter line, the valve having an open position below a predetermined pressure and a closed position above said predetermined pressure; b. a water supply means, of greater volume than the emitter line, connected to the pressure sensitive valve; c. a shut off valve at the entrance end of the water supply means; d. and a pressure relief valve for the water supply means; c. and said timer periodically actuating the shut off valve to supply water at a pressure above the closing pressure of the pressure sensitive valve, thereby to permit drainage of the emitter line, and alternately actuates the pressure relief to drop the pressure in the water supply means to open the pressure sensitive valve, thereby to fill the emitter line.

Claim 5

An intermittent irrigation system as defined in claim 3, wherein: a. the water supply means includes an upwardly extending reservoir dimensioned to contain water augmenting the water available to fill the emitter line.

Claim 6

An intermittent irrigation system as defined in claim 1, wherein: a. the control means includes a pressure sensitive valve having an elastomeric tubular valve element normally forming a central passageway, the external surface of the valve element being exposed to inlet pressure, the valve being collapsible in response to external pressure above a predetermined pressure to close the emitter line thereby to permit the emitter openings to drain the emitter line, the valve element being biased to remain open below said predetermined pressure to permit filling of the emitter line.

Claim 7

An intermittent irrigation system as defined in claim 1, wherein the control means comprises: a. a solenoid valve at the entrance end of the emitter line; b. a switch for sensing a filled condition of the emitter line; c. a timer actuated switch; d. the timer actuated switch being operated to oPen the solenoid valve thereby to fill the emitter line, and the sensing switch thereafter operable to close the solenoid valve thereby to permit drainage of the emitter line.

Claim 8

An intermittent irrigation system as defined in claim 6, wherein: a. the sensing switch includes an elastomeric envelope extending into the emitter line and collapsible in response to pressure in the emitter line, a pair of contacts, and operating means in the envelope for effecting relative movement of the contacts upon collapse of the envelope.

Claim 9

An intermittent irrigation system as defined in claim 1, wherein: a. the emitter line includes a series of risers, each terminating in a sprinkler head; b. pressure sensitive valves control discharge from the emitter openings to stop flow therethrough, when the emitter line is subjected to a predetermined pressure sufficient to activate the sprinkler heads, and to permit flow through the emitter openings, when the emitter line is subjected to pressure below said predetermined pressure; c. said control means are operable below said predetermined pressure; d. and means is provided to supply water to the emitter line at a pressure above said preselected pressure to close the emitter openings and cause operation of the sprinkler heads.

Claim 10

An intermittent irrigation system as defined in claim 8, wherein: a. the pressure sensitive valve includes an elastomeric tubular valve element normally biased to form an open passageway, the valve element being collapsible in response to upstream pressure to stop flow therethrough.

Claim 11

An intermittent irrigation system, comprising: a. a plurality of emitter lines, each emitter line having a plurality of emitter openings, the cumulative area of the emitter openings in each emitter line being less than the capacity of the corresponding emitter line; b. control means causing the emitter lines to undergo alternate filling and drainage cycles to effect intermittent discharge of water from the emitter openings, the emitter openings being spaced, positioned, and of such relative size as to discharge essentially equal volumes of water during the drainage cycles; c. and a timer for controlling the spacing and duration of the filling and draining cycles of the emitter lines, thereby to predetermine the total volume of water discharged during an irrigation period.

Claim 12

An intermittent irrigation system, comprising: a. a plurality of emitter lines, each emitter line having a plurality of emitter openings, the cumulative area of the emitter openings in each emitter line being less than the capacity of the corresponding emitter line; b. control means causing the emitter lines to undergo alternate filling and drainage cycles to effect intermittent discharge of water from the emitter openings, the emitter openings being spaced, positioned, and of such relative size as to discharge essentially equal volumes of water during the drainage cycles; c. and a timer for controlling the spacing and duration of the filling and draining cycles of the emitter lines, thereby to predetermine the total volume of water discharged during an irrigation period.

Claim 13

An intermittent irrigation system as defined in claim 10, wherein the filling-draining means comprises: a. a set of inlet valves for the emitter lines, the inlet valves adapted to close in response to inlet pressure above a predetermined pressure, thereby to permit the emitter line to undergo a draining cycle, and adapted to open in response to inlet pressure above said predetermined pressure thereby to permit the emitter lines to undergo a filling cycle; b. and means controlled by said timer to apply inlet pressure to the inlet valves alternately above and below said predetermined pressure.

Claim 14

An intermittent irrigation system as defined in claim 10, wherein, the filling-draining means comprises: a. at least one solenoid valve for the emitter lines; b. a timer actuated switch operable to open the solenoid valve to initiate a filling cycle; c. and at least one sensing switch to detect completion of the filling cycle and close the solenoid valve to initiate a draining cycle.

Claim 15

An intermittent irrigation system as defined in claim 10, wherein: a. a set of solenoid valves, timer actuated switches and sensing switches are provided for sequential operation of the emitter lines.

Claim 16

An intermittent irrigation system as defined in claim 10, wherein: a. each intermittent line includes risers terminating in sprinkler heads; b. pressure response valves are included in the control means adapted to stop flow through the emitter openings in response to pressure in the emitter lines sufficient to cause operation of the sprinkler heads and to permit flow through the eMitter openings at pressures in the emitter lines insufficient to cause operation of the sprinkler heads; d. and means is provided to select operation of the sprinkler heads or the emitter openings.

Claim 17

A pressure sensitive valve, comprising: a. housing having a valve chamber, an inlet and an outlet; b. a tubular elastomeric valve element in the valve chamber internally exposed to the outlet and inlet and externally exposed to the inlet only; c. the valve element having a pair of opposed, essentially arcuate side walls joined abruptly at diametrically opposite sides of the valve element, the side walls being relatively thin at their junctures thereby to permit folding of the side walls into mutual sealing contact, the side walls increasing in thickness from their junctures provide a predetermined resistance to pressure differential before being forced into mutual sealing contact.

Claim 18

A pressure sensitive valve, comprising: a. housing having a valve chamber, an inlet and an outlet; b. a tubular elastomeric valve element in the valve chamber internally exposed to the outlet and inlet and externally exposed to the inlet only; c. the valve element having a pair of opposed, essentially arcuate side walls joined abruptly at diametrically opposite sides of the valve element, the side walls being relatively thin at their junctures thereby to permit folding of the side walls into mutual sealing contact, the side walls increasing in thickness from their junctures provide a predetermined resistance to pressure differential before being forced into mutual sealing contact.

Claim 19

A pressure sensitive switch for insertion into a fluid receiving tubular member, said switch comprising: a. a housing communicating with the tubular member; b. a collapsible elastomeric envelope within the housing, its exterior being exposed to pressure in the tubular member; c. a pair of relatively movable contacts exposed to the interior of the envelope; d. an operating means extending into the envelope and movable upon collapse of the envelope to actuate the contacts; e. means forming a closed chamber; f. a valve connecting the envelope and chamber, the valve means permitting ready flow into the sealed chamber on collapse of the envelope and restricted flow from the chamber to the envelope to provide a time delay.

Claim 20

A pressure sensitive switch for insertion into a fluid receiving tubular member, said switch comprising: a. a housing communicating with the tubular member; b. a collapsible elastomeric envelope within the housing, its exterior being exposed to pressure in the tubular member; c. a pair of relatively movable contacts exposed to the interior of the envelope; d. an operating means extending into the envelope and movable upon collapse of the envelope to actuate the contacts; e. means forming a closed chamber; f. a valve connecting the envelope and chamber, the valve means permitting ready flow into the sealed chamber on collapse of the envelope and restricted flow from the chamber to the envelope to provide a time delay.