Apparatus for pneumatically supporting flexible ribbons and sheets out of contact with solids

Claim 2

The apparatus of claim 2, each said slot of exhaustion having a width measured in said direction, of about 1.5 to 2 mm.

Claim 3

The apparatus of claim 2, the distance between each slot of emission and the slot of exhaustion nearest thereto, being a fraction only of the distance between each said pair of slots of emission, all distances being measured in said direction.

Claim 4

The apparatus of claim 4, each said slot of exhaustion being defined by a respective pair of two plates spaced in said direction and having a vertical dimension normal to said direction, of about 40 mm., the upper edges of said plates defining a portion of said first surface.

Claim 5

The apparatus of claim 5, and a multiplicity of hollow conduits each interposed between and having its opposed side walls spaced from a respective contiguous one of said plates, to thereby form a slot of emission.

Claim 6

The apparatus of claim 6, and means connected with each said hollow conduit to supply heat exchange fluid thereto.

Claim 7

The apparatus of claim 6, said hollow conduits being rectangular in vertical planes parallel with said direction.

Claim 8

The apparatus of claim 6, said hollow conduits being trapezoidal in vertical planes parallel with said direction, the longer of the two parallel sides of the trapezoid being uppermost and lying in said flat upper surface.

Claim 9

Apparatus for the pneumatic support of moving sheet comprising a bed having a flat, horizontal surface and a supporting unit comprising a series of parallel slots of gas emission and discharge extending into the bed from the surface thereof transversely to the motion of the sheet and parallel to one another, means to supply the slots of emission with gas under pressure, means to dispose of the gas from the discharge slot, the slots of emission and discharge being arranged so that a slot of discharge is separated from each of two slots of emission by a narrow area of flat surface, and two slots of emission are separated from each other by a broad area of flat surface, whereby there is provided above the broad area a zone of substantially constant pressure, and above the narrow areas zones of pressure decreasing toward the discharge slot.

Claim 10

Apparatus according to claim 10 in which each slot of emission has substantially parallel walls choked by a filling of gas-pervious, flow-impending means.

Claim 11

Apparatus according to claim 10 which includes heat-exchanging means operatively connected to the broad area of flat surface.

Claim 12

Apparatus according to claim 10 in which the bed comprises a repeating sequence of such units, heat-exchanging means is operatively connected to a plurality of broad surfaces, and means are provided to operate different heat-exchanging means individually at different rates of heat exchange.

Claim 13

Apparatus according to claim 10 in which the broad area is the top of a prism-shaped hollow body fitting into a prism-shaped recess in the bed, the inclined sides of which constitute the walls of slots of emission.

Claim 14

Apparatus according to claim 10 in which the slots are uninterrupted throUghout the width of the sheet and the distance between two slots of emission is the major part of the distance between two discharge slots.

Claim 15

The apparatus of claim 11 said pervious gas flow-impeding means comprising gas-pervious fabric.

Claim 16

The apparatus of claim 10, each said portion of said flat surface between two consecutive slots of emission comprising an exterior upper surface of a respective one of a plurality of ducts extending transversely of said direction, and conduit means supplying heat exchange fluid to each said duct.

Claim 17

The apparatus of claim 10 each said portion of said flat surface between each consecutive pair of slots of emission defining an area of relatively static constant pressure beneath and supporting the sheet.

Claim 18

The apparatus of claim 10 the width of the slots of emission and of exhaustion, being about 1 mm. and 2 mm., respectively.

Claim 19

The apparatus of claim 13 the dimensions of the surface between each pair of consecutive slots of emission, measured in said direction, increasing downstream.

Claim 20

Apparatus according to claim 13 in which the area between said slots of emission is at least 60 percent of the total surface area of said flat surface.

Claim 21

The apparatus of claim 10, and means to maintain the air emerging from at least some of said slots of emission at a temperature different from that emerging from the remaining slots of emission.

Claim 22

The apparatus of claim 16, said pervious air flow impeding means comprising refractory wire mesh.