US 4,050,911 AGranted

Gas chromatograph oven

AssigneeHewlett-Packard Company

InventorPaul Bryce Welsh

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Abstract

A method for cooling gas chromatograph ovens with ambient room temperature air utilizing two separate air passages through an oven door. The door remains closed during the heating and cooling cycles which take place inside the oven housing. A rotating stirring fan internal to the oven creates regions of relatively higher and lower air pressures. The two air passages are disposed adjacent to these pressure regions to draw room temperature air into the oven, and to exhaust hot air from the oven. Within the oven door there is a movable, spring mounted, oven closure hatch in which the first air passage is located. This air passage is opened and closed by a movable cover. The hatch also establishes the second air passage when it is spaced-apart from the oven housing. Both air passages are opened and closed in response to movement of the hatch. An actuation device that can interface with a programmable actuation controller opens and closes the hatch as necessary for cooling the inside of the oven housing.

Claims9

Dependent claims

A gas chromatograph oven comprising:

a thermally insulated housing having an oven door assembly closing one side thereof, one side of said housing defining a first air passage;
p1 rotating stirring fan means for producing a high pressure region and a low pressure region within said housing;
said oven door assembly including:
a frame;
a hatch;
said hatch being movable into spaced-apart relation with said housing to define a second air passage;
spring biasing means disposed between said hatch and said door frame to maintain closure of the housing open side by said hatch;
cover means coupled with said hatch for selectively opening and closing said first air passage in response to the establishment and closure respectively, of said second air passage by movement of said hatch;
actuation means for moving said hatch in opposition to said hatch spring biasing means, thereby to establish said second air passage and to open said first air passage;
one of said first and second air passages being disposed adjacent said low pressure region to duct ambient room temperature air into said housing;
and
the other of said first and second air passages being disposed adjacent to said high pressure region to exhaust air from said housing.

9 more elements

Dependencies are inferred from the claim text.