Despatch Industries Limited

Despatch Industries Limited Partnership

Louis A Larson

Hans L Melgaard

Wendell L Schafer

Eric W Nelson

Brian E Hajder

Phillip G Jordon

The present invention provides a method of heat-treating an oxygen-sensitive workpiece to minimize any oxidation of the workpiece, as well as an improved door seal specially suited for use with oxygen-sensitive products. In the method, an oven has an oven chamber and an outer housing, with an enclosure being defined therebetween. The workpiece is placed in the oven chamber and the chamber is sealed. Heated inert gas is circulated within the enclosure to heat the oven chamber and to hold it at a desired treatment temperature. The oven chamber is then cooled to a threshold temperature of the workpiece using inert gas. The chamber is then cooled further by circulating aerobic gas, preferably ambient air, within the enclosure. Another embodiment of the invention provides an oven with a housing forming an oven chamber, the oven chamber having a door opening in one of said walls. The oven also has a heated door and an inflatable seal carried by either the door or the housing, the seal extending about the area of contact between the door and the housing, the seal being filled with a nitrogen-containing gas.

Method of heat treating oxygen-sensitive products

The invention provides an oven which can be used to rapidly heat and cool a workpiece. In one embodiment, the oven includes a first duct which defines an initial leg of an enclosed air flow path and which has an inner panel and a heat exchanger. This first duct has an inlet end and an outlet end, the inlet end of which is connected to a temperature-controlled air supply. The oven also includes a second duct which defines a final leg of the enclosed air flow path and which has an inner panel spaced from the first duct's inner panel to define an oven cavity. The oven also has a connecting conduit connecting the outlet end of the first duct to the second duct and which defines an intermediate leg of the enclosed air flow path. In a preferred embodiment, the first duct is the lower of the two ducts and includes a plurality of holes through at least the inner panel of the duct. A plurality of selectively actuatable lifting pins extend through these holes in the first duct and the pins are adapted to lift a workpiece upwardly off of the inner panel.

Rapid cycle treatment oven

An apparatus for testing peroxide concentration in a gaseous sterilant. A preferred embodiment of the apparatus includes a condenser for condensing the gaseous sterilant into a liquid condensate; an aliquot collector of predetermined volume to receive the condensate; a reaction chamber containing a catalyst for dissociating the peroxide; and a pressure monitor for detecting pressure changes in the reaction chamber as a function of time. The pressure monitor of this apparatus is capable of detecting a threshold pressure and an upper pressure and it includes a timer to measure time change between detection of the threshold pressure and the upper pressure.

Apparatus for testing peroxide concentrations in sterilants

The present invention, in one embodiment, provides a testing apparatus for electronic components to monitor their behavior at elevated temperatures. The invention comprises a transport belt with at least one carrier attached to the transport belt, the carrier being capable of retaining an electronic component. The carriers are adapted to contact bus bars positioned adjacent the transport belt to electrically connect a component retained by the carrier to an electrical power supply. The apparatus includes means for ramping up the electrical power applied to the component from an initial low voltage to a second, testing voltage. The apparatus includes a housing defining an oven cavity through which the transport belt may pass and means providing for maintaining the ambient temperature within a portion of the cavity at an elevated temperature and other embodiment, the carrier of the present invention comprises a slot for releasably retaining an electronic component and a retaining bar movable between the first component retaining position and a second, component releasing position, the retaining bar being capable of preventing electronic components from falling out of the slots when the carrier is inverted. In other embodiment, the present invention comprises a method for testing electronic components generally comprising the steps of operatively connecting an electronic component to an electrical power source, gradually increasing power from an initial low power level to a higher testing power level, placing the component in an elevated temperature environment, monitoring the behavior of the component at the elevated temperature while supplying electrical power to the component, and disconnecting the electronic component from the electrical power source.

Electronic component testing oven

A method and apparatus for automatically inserting and ejecting electrical connectors of electronic component test trays from electrical connectors in a panel of an environmental test chamber, e.g. an oven, at the beginning and end of a test period to facilitate loading and unloading the test trays. The electronic components are inserted into test trays so that electrical connections are made with test tray conductors which terminate at a test tray connector. The trays are loaded into the oven in an insertion cycle by manually sliding them onto lateral tray supports with the tray connector ends aligned with mating electrical connectors in the panel of the test oven. The insertion cycle of a track guided, carriage mounted, inserter/ejector mechanism is commenced wherein the mechanism is advanced from tray to tray to sequentially insert the tray connectors into the panel mounted connectors until all trays are inserted. The oven door is closed and the test is conducted. Upon completion of the test, the door is opened and the ejection cycle of the mechanism is initiated to sequentially eject the tray connectors from the panel mounted connectors until all trays are ejected. During insertion and ejection of each tray, the mechanism rotates one or more pivot arms about pivots to apply their free ends against the trays to move the trays on the lateral tray supports a constant distance to ensure reliable connection or removal of the tray from the panel mounted connectors. As the mechanism carriage traverses the ends of the trays a tray position trip sensor detects any out of position trays. The mechanism decreases operator fatigue and errors due to improperly seated connectors.

Growing community of inventors

Golden Valley, MN, United States of America

Louis A Larson