Abstract: The invention is called a "Chainbar" because it may be quickly and easily adjusted to have the characteristics of a flexible chain and/or that of a rigid bar; and may be easily folded into any size rectangular solid of equal volume. It consists of a series of interconnected links, which are flexible like a chain, but have means for restricting the movement between the links, to form a rigid bar. If the Chainbar is in the form of a flexible chain, and is passed through a tube which may be less than one link long, and has proper activating tabs, the movement between links will be sequentially restricted to form a rigid bar, adjustable in length in one link increments. The Chainbar has ubiquitous uses. It may anchored at one end and have a device attached to the other end, that may be extended out and away from the anchored end, such as a mirror, microphone, light source, etc. It may be used as folding handles or legs in folding, compact items such as tables, tripods, luggage carriers, etc.

Abstract: A folding cart, unique in that it can be made small and light enough to be hand carried, yet when unfolded, to have the advantages of a large cart using four wheel assemblies that swivel.

Abstract: A high efficiency labyrinth type enclosure uses chambers of triangular crossectional area and a single speaker with two separate voice coils, in conjunction with two speaker back wave paths, one tuned for woofer frequencies and the other tuned for subwoofer frequencies, to simultaneously reproduce all woofer and subwoofer frequencies of both channels of a stereo signal.