Differential pressure indicating apparatus

Claim 2

A differential pressure sensing unit comprising: a. a pressure tight housing defining an internal cavity; b. an expansion bellows mounted within said housing cavity free to expand and contract therein in response to differential pressures to which it is exposed; c. a first inlet means for receiving an inlet pressure of a first value for supply within said cavity in external relation to said bellows; d. a second inlet means for receiving an inlet pressure of a second value for supply to internally of said bellows; e. a movable lever secured to said bellows and extending in a direction laterally therefrom, said lever being operably responsive to expansion and contraction movement of said bellows for transmitting a correlated movement thereof; f. an output arm external of said housing; and g. a pivot flexure connecting said lever to said output arm for transmitting bellows movement of the former to the latter, said pivot flexure defining a rotational center pivot intersection transmitting said lever arm movement in a first direction to output arm movement in a second direction ofFset from said first direction.

Claim 3

A differential pressure sensing unit according to claim 1 in which said first and second movement directions are at substantially right angles to each other.

Claim 4

A differential pressure sensing unit according to claim 1 in which said pivot flexure includes a plurality of flexure members arranged in cross planes defining said rotational center pivot intersection.

Claim 5

A differential pressure sensing unit according to claim 3 in which said flexure members include a flexible diaphragm secured at its outward extend and sandwiched transversely intermediate said lever and said output arm and a pair of individual flexures connecting said output arm to said housing and arranged extending in a coincident plane intersection said diaphragm with the effective center thereof.

Claim 6

A differential pressure sensing unit to claim 4 in which said individual flexures and said diaphragm extend in planes substantially perpendicular to each other.

Claim 7

In a pressure indicating apparatus including pressure responsive means bidirectionally movable, and means operably connecting to said pressure responsive means for correlated movement in conjunction therewith relative to a null-position, the improvement comprising a differential pressure sensing unit for movably operating said pressure responsive means in response to differential pressure changes from a plurality of sensed pressure sources, said differential pressure unit comprising: a. a pressure tight housing defining an internal cavity; b. an expansion bellows mounted within said housing cavity free to expand and contract therein in response to differential pressures to which it is exposed; c. a first inlet means for receiving an inlet pressure of a first value for supply within said cavity in external relation to said bellows; d. a second inlet means for receiving an inlet pressure of a second value for supply to internally of said bellows; e. a movable lever secured to said bellows and extending in a direction laterally therefrom, said lever being operably responsive to expansion and contraction movement of said bellows for transmitting a correlated movement thereof; f. an output arm external of said housing operably connecting to said pressure responsive means; and g. a pivot flexure connecting said lever to said output arm for transmitting bellows movement of the former to the latter, said pivot flexure defining a rotational center pivot intersection transmitting said lever arm movement in a first direction to output arm movement in a second direction offset from said first direction.

Claim 8

In a pressure indicating apparatus including pressure responsive means bidirectionally movable, and means operably connecting to said pressure responsive means for correlated movement in conjunction therewith relative to a null-position, the improvement comprising a differential pressure sensing unit for movably operating said pressure responsive means in response to differential pressure changes from a plurality of sensed pressure sources, said differential pressure unit comprising: a. a pressure tight housing defining an internal cavity; b. an expansion bellows mounted within said housing cavity free to expand and contract therein in response to differential pressures to which it is exposed; c. a first inlet means for receiving an inlet pressure of a first value for supply within said cavity in external relation to said bellows; d. a second inlet means for receiving an inlet pressure of a second value for supply to internally of said bellows; e. a movable lever secured to said bellows and extending in a direction laterally therefrom, said lever being operably responsive to expansion and contraction movement of said bellows for transmitting a correlated movement thereof; f. an output arm external of said housing operably connecting to said pressure responsive means; and g. a pivot flexure connecting said lever to said output arm for transmitting bellows movement of the former to the latter, said pivot flexure defining a rotational center pivot intersection transmitting said lever arm movement in a first direction to output arm movement in a second direction offset from said first direction.

Claim 9

In a pressure indicating apparatus according to claim 6 in which said first and second movement directions are at substantially right angles to each other.

Claim 10

In a pressure indicating apparatus according to claim 6 in which said pivot flexure includes a plurality of flexure members arranged in cross planes defining said rotational center pivot intersection.

Claim 11

A differential pressure sensing unit according to claim 8 in which said flexure members include a flexible diaphragm secured at its outward extend and sandwiched transversely intermediate said lever and said output arm and a pair of individual flexures connecting said output arm to said housing and arranged extending in a coincident plane intersecting said diaphragm with the effective center thereof.