Abstract: A liquid flow detecting device incorporates a static member arranged to be fixed within a passage through which flow of an operating liquid is to take place and an active member held captive by the static member but free to move relatively to the static member to a limited extent in one particular direction at least. The active member has an overall specific gravity substantially the same as that of the chosen operating liquid. Proximity sensing apparatus is included to detect movement of the active member relative to the static member in the particular direction and to issue a corresponding signal.

Abstract: A liquid flow indicator for use in an automatic sprinkler system. The indicator is adapted to be attached to a water line and includes a non-metallic vane retainer or support which is mounted within an opening in the water line. A flexible one-piece plastic vane is pivoted to the retainer and has a generally circular body portion which is disposed transversely within the pipe. If the water line is opened downstream of the indicator, the flow of water within the line will pivot the vane, causing a magnet in the upper end of the vane to move into proximity with a sensor to complete an electrical circuit and generate a signal indicating that the water line has been opened. The retainer is formed with a pair of aligned recesses which are sealed apart by a central wall and the upper head of the vane which contains the magnet, is located in one recess, while the sensor is in the other recess.

Abstract: A flow responsive device for use in a fluid flow system to establish a signal when a predetermined flow rate is attained within a flow conduit. The device is adapted for connection to a flow conduit and has a target vane adapted for insertion within the flow conduit for movement in response to predetermined flow to open internal valve means against the bias force of a compression spring and control pressure within a pressure chamber. In operation, the control pressure is maintained at a higher pressure than the fluid pressure within the flow conduit so that after initial opening of the valve means, the control pressure drops and the valve means undergoes fast-action movement to its fully open condition. The flow rate at which the valve means closes is less than the flow rate at which the valve means opens so that hunting of the valve means during operation is prevented.

Abstract: A device capable of sensing forces exerted by fluids, particularly liquids, and thus may be used to sense fluid level and fluid flow. Preferred embodiments of the device include a switch means capable of being actuated without the exertion of substantial mechanical force thereon and an elongated body of low mass mounted for pivotal movement about an end thereof with switch actuation means at an end thereof in operative relation to the switch means only when the axis of elongation of the body is aligned with the switch means. Features of the device provide reduced inertial effects and reduced gravitational force requirements, as well as reduced wear, in operation.

Abstract: A gas flow indicator including an open-ended cylinder, a piston constrained within the cylinder to move between the ends thereof, and a reed switch positioned on the outside of the cylinder for responding to the position of a magnet secured to the piston is disclosed. The piston is closed at its end adjacent the output aperture of the cylinder and is open at its end adjacent the input aperture of the cylinder for defining a basin within the piston. A spring is positioned between the piston and the output aperture for forcing the piston away from the output aperture. Gas flowing in through the input aperture forces the piston toward the output aperture. An indication of the state of gas flow through the cylinder is provided in accordance with whether the switch is open or closed.

Abstract: A tubular section is provided through which fluid can flow. A paddle is mounted in the tubular section and is biased by a spring to a "no-flow" position, at least partially across the tubular section. Fluid flowing through the tubular section rotates the paddle to a "flow" position which is aligned and not across the tubular section. The device has been improved by having a signaling means in the form of a magnet mounted on the paddle in the tubular section for signaling when the paddle is in one of its positions. A switch mounted adjacent the tubular section receives the signal from the magnet and activates an indicator when it receives the signal so that the indicator indicates the position of the paddle. The paddle covers approximately one half of the cross section of the tubular section when the paddle is in the no-flow position. A baffle may be provided adjacent the paddle to direct flow to the portion of the tubular section through which the paddle moves.

Abstract: In an automobile, a device for monitoring the flow and temperature of the coolant in the internal combustion engine, comprising a switch of a supply circuit for an alarm, whose mobile part is controlled by a single detector detecting both flow and temperature, disposed at one point of the cooling circuit.