Pulsator for irrigation systems and the like

In an irrigation system comprising a source of pressurized liquid, a distributor for discharging said liquid intermittently therefrom and a pulsator connected between said source and said distributor, said pulsator comprising

• a pulsator inlet for receiving pressurized liquid thereof from said source,
• a pulsator outlet for emitting said liquid in intermittent pulses to said distributor,
• a casing defining a cavity therein,
• a mounting member disposed in said cavity,
• an elastomeric tube means, defining an expansible chamber therein and disposed between said casing and said mounting member, for movement from a normally contracted condition when the pressure of the liquid in said chamber falls below a predetermined level to an expanded condition when the pressure of the liquid in said chamber exceeds said predetermined level,
• flow control means between said pulsator inlet and said chamber for controlling the flow rate of said liquid into said chamber,
• valve means, normally closed when said tube means is in its contracted condition and defined between said mounting member and said tube means, for intermittently opening to discharge liquid from said chamber through said pulsator outlet in said intermittent pulses at at least substantially regular frequencies and uniform discharges in response to the pressure of the liquid in said chamber intermittently exceeding said predetermined level,
• inlet means, including an annular clearance defined between said mounting member and said tube means for continuously and unobstructively communicating liquid directly from said flow control means and into said chamber when said tube means is in both its contracted condition closing said valve means, and its expanded condition, and
• slot means defined radially between said mounting member and said tube means to be continuously exposed to said chamber for continuously communicating liquid from said inlet means to an inlet side of said valve means.

A generally cylindrical elastomeric pulsator tube mounted on a mounting member to define an expansible chamber therein having an inlet and to further define a valve means with said mounting member, said tube, when in its relaxed and pre-installed condition, comprising

• a cylindrical first portion forming said valve means with its engagement with underlying surface portions of said mounting member, and
• annular undercut means defined internally on said tube at a lower end of said first portion for maintaining a second portion of said tube essentially in out-of-contact relationship with respect to an underlying portion of said mounting member, said mounting member being in the form of a generally tubular pin comprising an outlet port, having an inlet adapted to communicate with said chamber and an outlet, and wherein said valve means comprises said first portion of said tube that normally engages said pin to cover upstream and downstream sides of the inlet to said outlet port when said tube is in a contracted condition and having sufficient flexibility to disengage said pin at the upstream side of said inlet to uncover the inlet to said outlet port when said tube is in an expanded condition, and an annular flange on said pin defining an annular contracting surface positioned on the upstream side of the inlet to said outlet port and normally engaged in an at least near line contact with the first portion of said tube when said tube is in its contracted condition, and slot means defined radially between said mounting member and said tube to be continuously exposed to said chamber for continuously communicating liquid from the inlet to said chamber to the downstream side of the inlet to said outlet port.

In an irrigation system comprising a source of pressurized liquid, a distributor for discharging said liquid intermittently therefrom and a pulsator connected between said source and said distributor, said pulsator comprising

• a pulsator inlet for receiving pressurized liquid therein from said source,
• a pulsator outlet for emitting said liquid in intermittent pulses to said distributor,
• a casing defining a cavity therein,
• a mounting member disposed in said cavity,
• an elastomeric tube means, defining an expansible chamber therein and disposed between said casing and said mounting member, for movement from a normally contracted condition when the pressure of the liquid in said chamber falls below a predetermined level to an expanded condition when the pressure of the liquid in said chamber exceeds said predetermined level,
• flow control means between said pulsator inlet and said chamber for controlling the flow rate of said liquid into said chamber,
• valve means, normally closed when said tube means is in its contracted condition and defined between said mounting member and said tube means, for intermittently opening to discharge liquid from said chamber through said pulsator outlet in said intermittent pulses at at least substantially regular frequencies and uniform discharges in response to the pressure of the liquid in said chamber intermittently exceeding said predetermined level, each of said casing and said tube means being generally cylindrical and opposite ends of said tube means being clamped between said casing and said mounting member, and
• slot means defined radially between said mounting member and said tube means to be continuously exposed to said chamber for continuously communicating liquid from said pulsator inlet to a downstream side of said valve means.

In an irrigation system comprising a source of pressurized liquid, a distributor for discharging said liquid intermittently therefrom and a pulsator connected between said source and said distributor, said pulsator comprising

• a pulsator inlet for receiving pressurized liquid therein from said source,
• a pulsator outlet for emitting said liquid in intermittent pulses to said distributor,
• a casing defining a cavity therein,
• a mounting member disposed in said cavity,
• an elastomeric tube means, defining an expansible chamber therein and disposed between said casing and said mounting member, for movement from a normally contracted condition when the pressure of the liquid in said chamber falls below a predetermined level to an expanded condition when the pressure of the liquid in said chamber exceeds said predetermined level,
• flow control means between said pulsator inlet and said chamber for controlling the flow rate of said liquid into said chamber,
• valve means, normally closed when said tube means is in its contracted condition and defined between said mounting member and said tube means, for intermittently opening to discharge liquid from said chamber through said pulsator outlet in said intermittent pulses at at least substantially regular frequencies and uniform discharges in response to the pressure of the liquid in said chamber intermittently exceeding said predetermined level, and
• slot means defined in said mounting member to be continuously, openly and directly exposed to said chamber for continuously communicating liquid from said flow control means to an inlet side of said valve means.