A sealing arrangement is provided for a product weigh scale for a food
processing apparatus the weigh scale including a support for supporting a
product, a member that carries the support, and a weight sensor that
senses vertical load on the member. The sealing arrangement includes a
seal surrounding the member beneath the support, the seal having a first
sealing surface configured to be sealed against a cabinet, and a second
sealing surface. The seal is movable between an inactive position wherein
the second sealing surface is out of contact with the support and a
sealing position wherein the second sealing surface seals against the
support. The seal includes a stationary part having the first sealing
surface and a sliding part having the second sealing surface. A plurality
of springs urge the sliding part toward the sealing position and a source
of pressurized fluid is injected between the sliding part and the
stationary part to urge the sliding part toward the inactive position.
The pressurized fluid has a sufficient pressure to overcome the urging of
the springs and maintains the sliding part in the inactive position
during normal operation of the scale, wherein upon loss of the supply of
pressurized fluid, the springs cause the sliding part to assume the
sealing position.