Abstract: A skate guard of flexible resilient material defines a longitudinally extending upwardly opening groove of a width to receive a skate blade. Flexible fins extend into the groove from each side and are designed to be deflected downwardly by the insertion of a skate blade.

Abstract: An encoder treats a block of b bits of binary data as a number N and encodes it into eight values S1, S2 . . . S8 identifying it. The eight values are each selected from positive, negative and zero integer values; and the values are chosen so that a set of eight consists of all even integers or all odd integers and so that the sum of the eight values is 0 modulo 4. In the transmitter these values are modulated on a carrier for transmission. A receiver detects the received versions of the transmitted values, determining the number N and reconstituting the block of b bits.

Abstract: An electromagnetic display or indicator element comprises a disc having a permanent magnet perpendicular to the disc's rotary axis. The disc is controlled by a single high remanence pole piece which has its forward end transversely (relative to the viewing direction) located relative to the disc to exert the main control on the magnet therein and its rearward end located rearwardly of the center of the disc.

Abstract: Locations of a desired number of signal points for a double side band-quadrature carrier modulation system occupy the inner intersections of a multiplicity of concentric rings with a triangular grid. The signal point locations of the desired number on the outer partially occupied ring are provided with additional signal points at positions selected to provide that the centroid of the set of locations is at the center of the rings.

Abstract: A display or indicator element has a set of movable and a set of fixed vanes of contrasting colors. Each set of vanes encompasses what is substantially a circle in the viewing direction. The sets of vanes are arranged so that the moving vanes move between a position where they are hidden (in the viewing direction) behind the stationary vanes and a position where the moving vanes occlude the stationary vanes. In such movements each moving vane passes between a pair of stationary vanes. Accordingly, contrasting effects are produced. Preferably the actuation for the movable vanes is electromagnetic.

Abstract: A game board assembly provides a central column designed to stand upwardly on a horizontal surface. Three or four playing boards are connected to the base of said column and extend outwardly from the base in directions which are approximately equally angularly spaced. The column is made from panels hinged together and the playing boards are hinged to the base of the panels. The entire assembly is capable of being folded into a stack when not in use and a four player or a three player game as desired.

Abstract: A sonic liquid atomizing device having a body member with a concave face and a resonator spaced from the face. An air nozzle projects through an opening in the face to form an annular aperture about the nozzle and an inlet for liquid connects with the annular aperture. The nozzle carries an axial stem on which the resonator is mounted and the nozzle is adjustable axially to vary the area of the annular aperture. The nozzle is tapered and its conical projection terminates on the axis of the stem between the resonator and a point one third of the distance between the resonator and the nozzle.

Abstract: A method and apparatus for obtaining a distorted photographic reproduction from a negative photographic image, in which a sheet of photosensitive printing paper is attached to a planar surface of a table, the image negative is placed over the paper and a slitted mask is placed over the image negative. The image negative and the mask are moved laterally relative to one another and to the paper while the mask is exposed to a light source. To obtain a circular reproduction the mask is held stationary and the printing paper is rotated about an axis intersecting the slit while the image negative is moved laterally with respect to the slit.

Abstract: A musical synthesizer keyboard has a plurality of keys mounted so that each key may be displaced along and return along a locus of movement and where during travel in either direction along said locus a key causes a change of state in each of two corresponding optical detectors at spaced locations along said locus. Means are provided for signalling the states of the detectors to other equipment.

Abstract: A pulp insulated electric communications conductor in which the wood pulp fibers of the insulation are coated with an aqueous cationic deposition aid polymer and then an aqueous based anionic latex polymer. In a process for applying a layer of insulating material to the conductor a slurry of wood pulp fibers is prepared to which first an aqueous based cationic deposition aid polymer is added and then an aqueous based anionic latex polymer is added, the resultant coated wood pulp fibers being applied to the conductor.

Abstract: Disclosed is a portable hydroponic unit comprising a nutrient containing trough which supports an plant supporting aggregate filled tray. Liquid nutrient is carried to the aggregate through an upwardly directed conduit, with apertures in the aggregate, by air bubbles supplied at the conduit lower open end by an air source.

Abstract: A disc filter is provided with undulating filter material formed by ridges and grooves extending radially and alternating circumferentially to increase the effective area of the filter.

Abstract: A step by step central office serving coin box subsets is provided with a link circuit which on initiation of a call from the coin box sub-set connects the line finder circuit through an auxiliary coin trunk circuit to the central office equipment. This is performed whether or not a coin has been deposited at the coin box sub-set. When the user of the coin box sub-set dials the auxiliary coin trunk determines whetherA. the call is charge or non-chargeB. if the call is charge whether or not adequate coinage been deposited.On this determination the auxiliary coin trunk is freed to serve another call. If the call is charge and adequate coinage has not been deposited the call is interupted by the link circuit. If the call is non-charge or adequate coinage has been deposited, the link circuit connects the line finder directly to central office equipment so the call may proceed.

Abstract: The cylindrical filter surface of a drum filter is increased in effective area by providing radial inward and outward undulations in the general cylindrical shape instead of the cylindrical surface of the prior art.

Abstract: A plurality of longitudinally extending mounting elements are designed to mount in a single row a plurality of magnetically actuable display elements. Each of the mounting elements is designed to be located side by side and in close proximity to other row mounting elements of the same type and at each end is provided with couplings designed to couple the element to a member extending transversely thereto. The coupling elements and the transversely extending member are so arranged that a plurality of the coupling elements located side by side may be coupled to the transversely extending member. Energizing windings for individual magnetic control of each of the display elements is provided rearwardly of the row elements. Thus the windings for all the row elements may be applied while the elements are arranged end - to - end and the elements may then be rotated parallel to each other, with the windings attached for assembly to the transverse member.