Dale Electronics, Inc.

John C Veburg

Jerome J Kneifel

A method and means for testing the flammability of combustible materials is disclosed with sensor elements for sensing ionization in the vicinity of the material to be tested. The utilization of spaced apart polarized plate elements for sensor elements provides flame detection by sensing the ionization caused by the flame while the alternate utilization of a pair of spaced apart polarized wire elements or sensing elements allows flame height determinations in addition to detecting the presence of a flame. The method for testing the flammability of a combustible material comprises causing combustion of the material to be tested, sensing ionization in the vicinity of the material and measuring the amount of current flow caused by the ionization. Combustion of the material is selectively, alternatively caused by applying electrical power to the material to cause a flame and applying a heat source to the exterior of the material to externally cause combustion. Ionization is sensed at selective predetermined levels above the material to determine flame height.

Method and means for testing the flammability of combustible materials

A testing chamber is generally comprised of a support structure, drawers for holding the modular test trays, timer, power supplies, and air blower. The support structure supports a plurality of drawers in horizontal position with the drawers supporting a plurality of test trays in a horizontal, parallel alignment. When a particular test allows air flow, air is blown into the plenum of the support structure, and passes through outlets of the support structure and into mating air inlets of the plena of the drawers. Flapper valves provide control of the air flow at the support structure outlets. The air then passes through a diffusing medium covering the slots of the drawers and up through air passages in the test tray such that there is no direct impingement of air on the components mounted on the modules. The diffusing medium maintains the air flow through the slots of the drawers at a uniform velocity whether test trays are present or not. A principal object of this invention is to provide the testing chamber which will accommodate a modular test tray for electrical resistors or the like which allows for a pressure chamber so that air can flow up between the units taking away heat and yet not allowing direct impingement of air on the components to be tested. A still further object of the invention is to provide a testing chamber capable of providing uniform velocity air flow to the components to be tested.

Electrical resistor testing chamber

A modular test tray is comprised of individual modules solidly detachably secured together and shorting straps for rapid and easy electrical connection between modules. Each module is comprised of two tuning fork shaped connector pins embedded in the module and capable of detachable mechanical and electrical engagement with the shorting straps. Two posts capable of receiving electrical components to be tested are also embedded in the module and electrically connected to the connector pins. The posts protrude from the top of the module while the connector pins are recessed in grooves on the bottom of the module. Shorting straps consisting of intermittent strips of electrical conducting material, the strips being of sufficient length to electrically connect only two connector pins of adjoining modules and spaced apart so as to electrically connect consecutive pairs of connector pins, allows a series electrical connection of the components to be tested. Shorting straps consisting of continuous electrical conducting material allow a parallel electrical connection of the components to be tested. The individual modules are selectively detachably mounted together to provide easy replacement of worn out modules and to allow variance of the test tray size to accommodate multiple lots sizes and value splits of components.

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Columbus, NE, United States of America

John C Veburg