Fluid damping system for analog instruments

Claim 2

An electrical measuring instrument comprising: a stator unit, a rotor unit, mounting means mounting the rotor unit on said stator unit for movement relative to said stator unit, damping means for damping said relative movement, said damping means comprising a receptable member carried by one of said units and having an outwardly opening aperture, said aperture having side and end walls, a damping member carried by the other of said units and having at least a portion thereof positioned within said aperture, and a highly viscous liquid damping fluid within said aperTure and through which said portion of said damping member moves as a consequence of the relative movement of said units, the properties of said liquid fluid being so related to the dimensions of said aperture that said liquid fluid will be retained within said aperture against the force of gravity.

Claim 3

The electrical measuring instrument of claim 1 wherein said portion of said damping member is a fingerlike part projecting from said damping member.

Claim 4

The electrical measuring instrument of claim 1 wherein said mounting means establishes an axis about which said rotor unit rotates relative to said stator unit.

Claim 5

The electrical measuring instrument of claim 3 wherein said aperture is of annular shape, said annular aperture having its center of curvature concentric with said axis.

Claim 6

The electrical measuring instrument of claim 4 wherein said portion of said damping member is substantially arcuate in shape and said portion has a wall, said wall having inner and outer peripheral wall surfaces, said wall being positioned within said aperture with said damping fluid touching said inner and said outer peripheral wall surfaces.

Claim 7

An electrical measuring instrument comprising: a first vane of magnetic material, a second vane of magnetic material, mounting means mounting said first vane for rotation about an axis relative to said second vane, means providing a flux path through said vanes, a winding assembly providing flux flow through said flux path whereby force is created between said vanes to produce said relative movement between said vanes, damping means for damping said relative movement, said damping means comprising a receptacle member fixed with respect to one of said vanes and having an outwardly opening aperture, said aperture having side and end walls, a damping member fixed with respect to the other of said vanes and having at least a portion thereof positioned within said aperture, and a highly viscous liquid damping fluid within said aperture and through which said portion of said damping member moves as a consequence of said relative movement of said vanes, the properties of said liquid fluid being so related to the dimensions of said aperture that said liquid fluid will be retained therein against the force of gravity.

Claim 8

An electrical measuring instrument comprising: a first vane of magnetic material, a second vane of magnetic material, mounting means mounting said first vane for rotation about an axis relative to said second vane, means providing a flux path through said vanes, a winding assembly providing flux flow through said flux path whereby force is created between said vanes to produce said relative movement between said vanes, damping means for damping said relative movement, said damping means comprising a receptacle member fixed with respect to one of said vanes and having an outwardly opening aperture, said aperture having side and end walls, a damping member fixed with respect to the other of said vanes and having at least a portion thereof positioned within said aperture, and a highly viscous liquid damping fluid within said aperture and through which said portion of said damping member moves as a consequence of said relative movement of said vanes, the properties of said liquid fluid being so related to the dimensions of said aperture that said liquid fluid will be retained therein against the force of gravity.

Claim 9

The electrical measuring instrument of claim 6 wherein said portion of said damping member is a fingerlike part projecting from said damping member.

Claim 10

The electrical measuring instrument of claim 6 wherein said aperture is of annular shape, said annular aperture having its center of curvature concentric with said axis.

Claim 11

The electrical measuring instrument of claim 8 wherein said mounting means comprises a taut band positioned along said axis and an anchor, said anchor having first and second arms and means securing an end portion of said taut band to said first arm, said damping member of said damping means including said second arm, said second arm extending generally longitudinally of said axis and into said aperture of said receptacle member, said second arm being radially outwardly spaced from said taut band.

Claim 12

An electrical measuring instrument comprising, a stator, a rotor, means mounting said rotor for rotational movement relative to said stator about an axis of rotation, an annular member carried by said stator concentrically of said axis of rotation, said annular member having an elongated outwardly opening arcuate aperture facing said rotor, a highly viscous liquid damping fluid within said aperture, the properties of said liquid fluid being so related to the dimensions of said aperture that said liquid fluid will be retained therein against the force of gravity, a damping member carried by said rotor and having a portion extending into said liquid fluid.

Claim 13

An electrical measuring instrument comprising, a stator, a rotor, means mounting said rotor for rotational movement relative to said stator about an axis of rotation, an annular member carried by said stator concentrically of said axis of rotation, said annular member having an elongated outwardly opening arcuate aperture facing said rotor, a highly viscous liquid damping fluid within said aperture, the properties of said liquid fluid being so related to the dimensions of said aperture that said liquid fluid will be retained therein against the force of gravity, a damping member carried by said rotor and having a portion extending into said liquid fluid.

Claim 14

The instrument of claim 10 in which said liquid fluid is polydimethylsiloxane approximately 30,000 centistokes, the width of said aperture being approximately 0.042 inch, the depth of saiD aperture being approximately 0.036 inch.

Claim 15

The instrument of claim 11 in which said portion of said damping member has a thickness of approximately 0.008 inch.

Claim 16

The instrument of claim 10 in which said means for mounting said rotor includes a pair of taut bands resiliently carried by said stator, said bands suspending said rotor for rotational movement, one of said bands extending through said annular member, said elongated aperture being concentric with said one band, a plate-like mounting member secured to said rotor, said plate-like member having an aperture therethrough, said one band extending through said aperture of said plate-like member and secured to said plate-like member, said damping member being an extending arm portion of said plate-like member and extending generally parallel to said one band and into said elongated aperture of said annular member.