Temperature differential sensing and control device

Claim 2

A heating system comprising a heat collector, a thermal reservoir, a first conduit leading from the reservoir to the collector, a second conduit leading from the collector to the reservoir, an electrically-operable pump connected to pump fluid from the reservoir, through the first conduit, the collector and the second conduit and back to the reservoir, and a differential thermostat which comprises a housing having mounted therewithin a flexible diaphragm which divides the interior of the housing into first and second chambers, first and second vessels having their interiors in communication with the first and second chambers respectively, the first vessel and the first chamber containing thermally expansible fluid sealed therewithin and the second vessel and the second chamber also containing thermally expansible fluid sealed therewithin, the first vessel being in thermally conductive contact with the first conduit and the second vessel being in thermally conductive contact with the second conduit, and the thermostat further comprising an actuating member mounted so as to be displaced by the diaphragm in dependence upon difference in pressure between the first and second chambers, and a control device mounted to be acted upon by the actuating member in dependence upon displacement thereof and connected to control supply of operating current to the pump.

Claim 3

A heating system as claimed in claim 1, wherein the diaphragm is provided with a support plate and the housing contains resilient means biasing the support plate to oppose the force exerted on the diaphragm by pressure in one of said chambers.

Claim 4

A heating system as claimed in claim 2, wherein the resilient means comprise a helical spring having two opposite ends, one of said ends bearing against said support plate and the other end bearing against a stop member mounted in the housing in a position which is adjustable to vary the opposing force exerted on the diaphragm by said spring.

Claim 5

A heating system as claimed in claim 1, comprising a photosensitive device connected in series with said control device and arranged to prevent supply of current to the pump except when exposed to light substantially of daylight intensity.

Claim 6

A hot water storage system comprising a storage tank, an inlet pipe connected to admit cold water to the tank, an outlet pipe connected to withdraw cold water from the tank and located above the inlet pipe, a conduit connecting the outlet pipe to the inlet pipe, heating means at a lower portion of the tank, a control thermostat arranged to detect the temperature at an upper portion of the tank and control heating of water in the tank by the heating means in dependence upon the temperature sensed by the control thermostat, an electrically-operable pump connected in said conduit for pumping water from the outlet pipe to the inlet pipe, and a differential thermostat which comprises a housing having mounted therewithin a flexible diaphragm which divides the interior of the housing into first and second chambers, first and second vessels having their interiors in communication with the first and second chambers respectively, the first vessel and the first chamber containing thermally expansible fluid sealed therewithin and the second vessel and the second chamber also containing thermally expansible fluid sealed therewithin, the first and second vessels both being in thermally conductive contact with the interior of the tank with the second vessel positioned above the first vessel, and the thermostat further comprising an actuating member mounted so as to be displaced by the diaphragm in dependence upon difference in pressure between the first and second chambers, and a control device mounted to be acted upon by the actuating member in dependence upon displacement thereof and connected to the pump to control supply of operating current thereto.

Claim 7

A hot water storage system comprising a storage tank, an inlet pipe connected to admit cold water to the tank, an outlet pipe connected to withdraw cold water from the tank and located above the inlet pipe, a conduit connecting the outlet pipe to the inlet pipe, heating means at a lower portion of the tank, a control thermostat arranged to detect the temperature at an upper portion of the tank and control heating of water in the tank by the heating means in dependence upon the temperature sensed by the control thermostat, an electrically-operable pump connected in said conduit for pumping water from the outlet pipe to the inlet pipe, and a differential thermostat which comprises a housing having mounted therewithin a flexible diaphragm which divides the interior of the housing into first and second chambers, first and second vessels having their interiors in communication with the first and second chambers respectively, the first vessel and the first chamber containing thermally expansible fluid sealed therewithin and the second vessel and the second chamber also containing thermally expansible fluid sealed therewithin, the first and second vessels both being in thermally conductive contact with the interior of the tank with the second vessel positioned above the first vessel, and the thermostat further comprising an actuating member mounted so as to be displaced by the diaphragm in dependence upon difference in pressure between the first and second chambers, and a control device mounted to be acted upon by the actuating member in dependence upon displacement thereof and connected to the pump to control supply of operating current thereto.

Claim 8

A differential thermostat comprising a housing having mounted therewithin a flexible diaphragm which divides the interior of the housing into first and second chambers, first and second vessels having their interiors in communication with the first and second chambers respectively, the first vessel and the first chamber containing thermally expansible fluid sealed therewithin and the second vessel and the second chamber also containing thermally expansible fluid sealed therewithin, and the thermostat further comprising an actuating member mounted so as to be displaced by the diaphragm in dependence upon difference in pressure between the first and second chambers, a control device mounted to be acted upon by the actuating member in dependence upon displacement thereof, said diaphragm being provided with a support plate and the housing contains resilient means biasing the support plate to oppose the force exerted on the diaphragm by pressure in one of said chambers and wherein the resilient means comprise a spring having two opposite ends with one end bearing against said support plate and the other end bearing against a stop member mounted in the housing in a position which is adjustable to vary the opposing force exerted on the diaphragm by said spring.

Claim 9

A differential thermostat comprising a housing having mounted therewithin a flexible diaphragm which divides the interior of the housing into first and second chambers, first and second vessels having their interiors in communication with the first and second chambers respectively, the first vessel and the first chamber containing thermally expansible fluid sealed therewithin and the second vessel and the second chamber also containing thermally expansible fluid sealed therewithin, and the thermostat further comprising an actuating member mounted so as to be displaced by the diaphragm in dependence upon difference in pressure between the first and second chambers, a control device mounted to be acted upon by the actuating member in dependence upon displacement thereof, said diaphragm being provided with a support plate and the housing contains resilient means biasing the support plate to oppose the force exerted on the diaphragm by pressure in one of said chambers and wherein the resilient means comprise a spring having two opposite ends with one end bearing against said support plate and the other end bearing against a stop member mounted in the housing in a position which is adjustable to vary the opposing force exerted on the diaphragm by said spring.