A forced air warming unit has a casing that encloses a scroll housing with
a curved inside surface. A blower is disposed in the scroll housing inside
the curved surface. Inlet and outlet openings are provided in the casing.
A circuit board is mounted in the casing, against the scroll housing so
that the blower is enclosed in space between the scroll housing and the
circuit board. At least one opening is provided through the circuit board
into the space in which the blower is disposed. A tapered, elongate,
arcuate heater plate is disposed in the scroll housing between the circuit
board and the blower, with a relatively wide end near the outlet opening
and a second, relatively narrower end near the curved inside surface. Air
is conducted in response to operation of the blower through the inlet
opening, along a first side of the circuit board through the one or more
openings in the circuit board into the scroll housing. Air is also
conducted in response to operation of the blower along a second side of
the circuit board which faces the scroll housing, through air passages in
the circuit board to and along the first side through the one or more
openings, into the scroll housing. Air entering the scroll housing in
response to operation of the blower is accelerated by the blower along the
curved inside surface while being heated in response to operation of the
heater plate. Heated, pressurized air exits the forced air warming unit
through the outlet opening. Provision is made for connecting an air hose
to the outlet opening for conducting the pressurized, heated air to a
pneumatic, convective device.
