Abstract: Pairs of complementary open-top containers are disclosed that can be stacked, one upon the other without covers or reorientation of one of the pair relative to the other. Similarly formed containers of multiple pairs can be nested for storage or transportation as empties. A pair of complementary containers are of similar polygonal shape in which the sidewalls are formed as complementary approximations of sine waves (sinusoids) having similar amplitudes, but whose frequencies are spacially displaced sufficiently so that interference is created between the ingoing and outgoing portions of a sufficient number of half waves forming the wave train so that the bottom portions of such waves on one container land on the top of oppositely phased waves on the complementary container.

Abstract: A self-tracking carpet caster of the inclined-disc type is disclosed, and the geometric relationships of its components and angles of inclination for optimum operation are defined. Lint protection means including a flexible sealing skirt and a grooved track construction are described, as in an improved locking structure and a simple interchangeable stem assembly construction which permits inexpensive adaptation of the caster to a wide variety of replacement uses.

Abstract: A dispensary type warehousing system featuring palletizing vehicle providing a mobile platform work station, together with pick aisles sufficiently narrow so that all merchandise to be picked is within the picker's reach without the need for leaving the vehicle. The invention makes it unnecessary for the picker to dismount from the mobile platform to perform his task, and this in turn permits partial automation of the vehicle control equipment as shown.