Shutter construction

Claim 2

A shutter construction comprising: a transparent housing; a louvre assembly adapted to be enclosed within said housing, said assembly comprising a plurality of lightweight foil louvres each rotatably supported at its end along parallel axes with first and second bearing pins; a crank drive member attached to one pin of each louvre for rotating said one pins and said louvres in unison about said parallel axes, said crank drive member and louvres having a combined mass center offset from said axes; counterbalance means coupled to said drive member for counterbalancing said offset mass center with respect to said axes; and drive means releasably secured to said housing and coupled to said crank drive member for moving said crank drive member in a direction normal to said axes.

Claim 3

The construction of claim 1 wherein said housing includes first and second transparent sheets which are supported and held in place at their edges, the sheet being sufficiently thin that they tend to sag when horizontal due to their weight, and brace means located centrally and normal to said sheets for holding the sheets apart in and their center region a distance further than they are spaced along their edges, thereby adding rigidity to the sheets.

Claim 4

The shutter construction of claim 1 wherein said drive means includes a motor, a gear train driven by said motor, and a lever rotated by said gear train for operating said crank arm, and motion limit means coupled to said lever for limiting the arc through which the lever rotates.

Claim 5

The shutter construction of claim 1 wherein each of said louvres comprise a like longitudinally ribbed generally S-shaped foil of highly reflective material.

Claim 6

A shutter construction comprising: a plurality of foil louvres; a bearing pin at each end of each louvre, said bearing pins of each louvre being aligned on a given axis; a crank on one end of each louvre coupled to one of said bearing pins, said crank including a drive arm offset from said given axis; bearing means for rotatably receiving each said bearing pins including means for restraining said louvres in a direction parallel to their corresponding axes; drive means including a crank drive member coupled to each said cranks at said drive arm, said drive member having a mass center offset from said axes for simultaneously rotating said louvres about said corresponding axes, said drive member circularly translating during said rotating, said drive member including counterbalance means for counterbalancing said drive member mass center during said rotating.

Claim 7

A shutter construction comprising: a plurality of foil louvres; a bearing pin at each end of each louvre, said bearing pins of each louvre being aligned on a given axis; a crank on one end of each louvre coupled to one of said bearing pins, said crank including a drive arm offset from said given axis; bearing means for rotatably receiving each said bearing pins including means for restraining said louvres in a direction parallel to their corresponding axes; drive means including a crank drive member coupled to each said cranks at said drive arm, said drive member having a mass center offset from said axes for simultaneously rotating said louvres about said corresponding axes, said drive member circularly translating during said rotating, said drive member including counterbalance means for counterbalancing said drive member mass center during said rotating.

Claim 8

The construction of claim 5 wherein said louvres each include a like reinforcing end bearing locating bend centrally the transverse dimension of that louvre and extending along the length of that louvre.

Claim 9

The construction of claim 6 wherein said louvres and bend comprises two louvre sections connected by a relatively short leg approximately normal to the sections at the point where connected.

Claim 10

The construction of claim 5 further including a light transparent housing enclosing said louvres.

Claim 11

The construction of claim 5 wherein said louvres are normally biased along a curve between said bearing means, said curve at a point midway between said bearing means being offset from the axis of rotation of the corresponding louvres an amount sufficient to compensate for sag of said louvres due to gravity and thereby result in straightening said louvres in the presence of that sag.

Claim 12

The construction of claim 5 wherein said drive means includes a drive crank rotatably connected to each said cranks and bimorph drive means connected to said drive crank.