A changeable display apparatus and method is disclosed which is made up of a group of similar individual character modules, disposed in a substantially continuous viewing surface, each module comprising support panel or base and a set of identical and changeable elements so it can represent any desired one of a character group, e. g. , any letter of the alphabet. Each display element comprises a molded two-piece housing body designed to pivotally support a rotatable magnetic display piece having a relatively visible light-showing or light-reflective face and a dark or non-visible face which can be moved selectively to a viewing position. Solenoid means individual for rotating each element show a desired face selectively, so that selected elements in any module as desired may be shifted either in unison, or preferably sequentially, to show individual display characters or symbols, such as a letter of the alphabet or an arabic numeral, etc. The light-showing face, per se, is designed preferably to operate essentially without electrical or other energy consumption. Access to mounting means for the elements on the base panel is provided by slightly truncating the corners of each housing body.
A casing or shell for explosive material to be used as a booster for detonating massive charges of blasting agents of low sensitivity is formed in two generally hemispherical half shell or casing members which are formed with sufficient precision that the two parts may lock together in telescoped relationship after filling, to form a liquid-tight joint. The two half shells are quite similar in size and shape but not identical, one bearing a flange having a hollow cylindrical inner surface into which a mating flange on the other is received; interlocking elements inside the outer flange and on the exterior surface of the inner flange hold the parts securely together by friction and without adhesive after full assembly. Each half shell includes a thin-walled tubular element which projects through and frictionally engages an opening in the other half shell as the two members are assembled, the parts being so arranged that a filling port and an air outlet port are provided when the parts are brought together but only partially closed to final position, these ports being closed completely when the two half shells are finally forced tightly together. The tubular elements are designed to receive and hold a primary detonator, such as an electric blasting cap or a length of detonating cord, and to hold such detonator securely in place after the booster is filled and sealed.
Apparatus and method are disclosed for presenting information over a display area, using a group of contiguous or substantially adjoining modules which essentially cover the area. Each module is made up of contiguously arranged elements, capable of presenting alternatively either a luminous (highly visible) or a non-luminous (much less visible) aspect. By selectively operating or energizing chosen elements in groups within each module, characters or symbols are presented which, collectively over the group of modules, presents the information to be displayed. Each module comprises a mounting base and an associated printed circuit board, referred to as a satellite board, having conductive element connected to each element of the module so that each element may be activated or energized, or deactivated selectively. The modules, in turn, are mounted so that the satellite board is connected electrically to a higher order control master or major printed circuit board. The latter is controlled, in turn, by mechanical or electronic means to selectively energize or activate the desired elements in all the modules, thus to present the information to be displayed.
A large display sign, or analogous visual or radiant energy display or collecting surface area, is made up of numerous frontal individual "radiation sensitive" display elements arranged contiguously but in module groups, covering the full display area without gaps. The module unit occupying each such square is supported on a "tile" or equivalent base. Each base supports through bifurcate hinged connector (BHC) means an insulated multiple conductor power buss, a module area portion of a first or rear most circuit board or panel, and a group of insulating penetrating contacts with attached wires supported by this BHC between the base and the rear panel. At eight, symmetrically arranged around its center, each module comprises a BHC for each point and multiple contacts around each BHC, some connected to the penetrating contact wires. A second panel bears rearwardly and forwardly extending contact pins for electric contact with the rear and with a front panel. Supplemental electronic means which participate in the controlling function are mounted on the intermediate panel.