Abstract: Operator enclosures or cabs in many cases have rear windows which are disposed in a generally upright or vertical position. The vertical position of the window reflects the instruments and dash as well as elements disposed forwardly of the cab during operation at night. The enclosure of the present invention includes a rear wall having lower wall portion and a upper wall portion. The upper wall portion is angled rearwardly from its lower edge to its upper edge and includes an opening for a window. A transparent window is sealably mounted in the opening and is thus also angled rearwardly at an angle sufficient to direct the reflection downward out of the operator's line of vision. This permits improved vision for the operator when operating in the dark.

Abstract: A door hold-open latch and dual release mechanism includes a first latch for maintaining the door in its closed position and a second latch for maintaining the door in its open position. A first latch release is mounted on the door in a position accessible to an operator located in the cab for releasing the first latch. A second latch release is mounted on the door in a position accessible to an operator located in the cab for releasing the second latch. A third latch release is mounted on the door in a position accessible to an operator located on the ground for also releasing the second latch. The operator can actuate the second latch from either the cab using the second latch release or from ground level using the third latch release. Alternately, the third latch release can also release the first latch, and the operator can actuate the first latch using the third latch release.

Abstract: A storage-stable, high potency allergenic extract is prepared by ultrafiltration, retaining fractions having molecular weights of from 1000 to 100,000, and drying the retained fraction to a moisture content of less than one weight percent. The extract can also be pretreated with amylase before ultrafiltration, treated with affinity chromatography before drying, and/or treated with gamma radiation after drying.

Abstract: A storage-stable, high potency allergenic extract is prepared by ultrafiltration, retaining fractions having molecular weights of from 1000 to 100,000, and treating the solution with gel polymer and/or carbon absorbents. The extract is dried to a moisture content of less than one weight percent water. The purified solution and aqueous reconstituted solutions of the dried extract provide a transparent, colorless solution which has greatly increased stability, remaining transparent and colorless for extended periods.