Abstract: A hollow structural element has a hollow member having a circumferential wall and a side wall which closes one of the axial ends of the circumferential wall, a cover member arranged to close the other end of the circumferential wall of the hollow member and connecting elements for connecting the structural element with other structural elements. The connecting elements include an undercut projection provided in the cover member and arranged for inserting into an undercut groove of another structural element, and an undercut lateral slot provided in the side wall of the hollow member and arranged for engaging with an undercut projection of a further structural element. The lateral slot has a first enlarged portion through which the projection of the further structural element can pass, and a second reduced portion extending from the first portion toward the axis of the circumferential wall and dimensioned so that the projection of the further structural element engages in the reduced portion.

Abstract: A multi-propeller propulsion system for model aircraft having a single engine and positive driving connections between the engine and each of the multiplicity of propellers. The positive drive may include toothed pulleys and serrated belts and gearing for example.

Abstract: Disclosed is a device advantageously usable for dental therapy and examination, which is an elongated bundle of axially extending fibers. The elongated bundle is tapered at one or both of its ends, and the fibers are bonded to each other in places along their lengths so that the fiber bundle is coherent and the fibers define capillary passageways therebetween.

Abstract: The element is adapted to be fitted as an annular band around a tooth and to be secured to a dental appliance to hold the same in position. It includes a strip metal element having two end portions, which are adapted to overlap in the annular band, a first slide-snap fastener part, which is carried by one of the end portions and includes a tunnel member defining a tunnel passage extending longitudinally of the strip metal element, and a detent spring secured to the tunnel member and extending longitudinally in the passage, a second slide-snap fastener which is carried by the other of the end portions and includes a plurality of barblike oblique detent teeth spaced apart in the longitudinal direction of the strip metal element and movable relative to the first fastener part in a closing direction into the tunnel passage.

Abstract: A beta-titanium alloy wire is used as the force-imparting component in orthodontic appliances. The alloy provides up to a threefold improvement over 18-8 stainless steel wire in load deflection rate and a twofold increase in maximum elastic displacement while providing a low modulus of elasticity and optimum low level force magnitudes. The wire also finds utility as ligature wires, as clasps and related structures in orthodontic and prosthetic appliances and as surgical arch bars for jaw fractures and the like.

Abstract: An educational toy is a doll of the stuffed variety having a fabric cover. The doll includes a trunk and body appendages, and the trunk has a cavity therein. A fabric door is hingedly connected to cover the cavity, and has indicia thereon. A baby doll is removably carried within the cavity.Self adherent patches are located at selected positions on the assembly whereby the baby doll is attachable to the main doll body.

Abstract: A hygienic instrument of a disposable type for use in cleaning surfaces within a person's mouth which is composed of a elongate member having a pointed end for picking the teeth and an opposite end with a foam pad or brush impregnated with a cleaning substance and including two laterally extending pegs spanned by a strand of dental floss, the laterally extending pegs being intermediate the length of the elongate member.

Abstract: A swingable toy for creating audible vibratory noises and concentric circles of light. First and second elongate end pieces are perpendicularly secured at opposite ends of a tubular central body portion. Noise-emitting vibratory rubber bands are disposed in a parallel and spaced apart relationship between slots disposed in the first and second end pieces. A stabilizing fin is secured to the tubular body portion in a plane perpendicular to that defined by the rubber bands for maintaining the rubber bands in perpendicular relationship to another plane defined by the swinging orbit for maximum vibratory excitement of the rubber bands. A cord is attached to one end of the tubular body through a metal eyelet and a low friction ball bearing is disposed in the cord to relieve twisting of the cord during swinging of the toy for maintaining the rubber bands in a plane perpendicular to that of the swinging orbit.

Abstract: A toy building set for constructing a toy building includes a plurality of wall plates having anchoring elements and a plurality of connecting members having recesses for receiving the anchoring elements, the recesses having clamping bars extending from opposed walls in the recess to clampingly engage opposite sides of the anchoring elements. Roof elements and other building parts are provided to complete the construction of the toy building.

Abstract: Honing and polishing instrument especially intended for dental use and being provided with a rotatable shaft. A replaceable honing or polishing unit made of a flexible elastic material can be attached to the free end of the shaft. An undercut indent in the unit embraces a radial sleeve at the free end of the shaft. The shaft also has an end portion extending axially beyond the sleeve which is inserted in a corresponding bore at the bottom of the indent in the unit.

Abstract: A thin articulating film which is susceptible of folding, wrinkling, crimping and the like is held taut in a generally U-shaped frame to which the film is permanently affixed at a part of its periphery. The edge of the film spanning the ends of the arms of the frame is unframed. The frame can be integral with the film. Devices for full-arch, anterior-arch and quadrant occlusal adjustment, and for contact adjustment between two adjacent teeth in one arch or another where one tooth or both may be a restoration, are described.

Abstract: A circular disk, having opposing flat surfaces, is provided with a spiral groove in one of the flat surfaces for receiving one end of a crank handle and horizontally rotating the disk about its axis and subsequent release of the disk by centrifugal force.

Abstract: A method and composition for the use of a cyanoacrylate resin and a silane-treated inorganic powder in direct bonding mount/bracket structures to teeth and other dental applications. The method and composition inhibit caries formation about the tooth structure interface and the adhesive is easily removed.

Abstract: A milling device for cutting a circular arcuate slot in a human jawbone, which slot is adapted to receive an endossal implant for mounting a denture. The device has a circular sawblade mounted in a housing comprising two parts. One part is adapted to slide into the other and carries the rotatably mounted sawblade. The other part serves as a guide to control the direction and distance the blade moves with respect to the bone being cut, thereby providing an accurately dimensioned slot for receiving the implant.

Abstract: A bonding material is disclosed for use in securing an orthodontic device, such as an orthodontic bracket, to a tooth. A pre-measured amount of an alphacyanoacrylate resin is provided in a syringe-like collapsible container. A pre-measured amount of an inert, finely divided particulate filler is provided in a bi-layered open-scrim cellulose package. In use, the filler package is placed between the orthodontic device and the tooth, and the resin is applied to the filler and filler package. Heat can be applied to shorten the resin cure time.

Abstract: A lighted and sounding yo-yo is provided with a single heavy duty battery in a first hollow shell section, and a lamp in both hollow shell sections. Flexible electrical conductors connect the lamps to the battery. A centrifugal switch is joined with the conductors in the second shell section so as to actuate the lamps only during rotation of the yo-yo. An audible electrical signal device is also located in the lighting circuit of the second shell. A second modification of the centrifugal switch is also shown. The heavy weight of the battery shell as compared with the light weight of the other shell causes the battery shell to dominate the yo-yo in the manner of a gyroscopic action to obtain rotational stability.

Abstract: An improved dental treatment tool includes a rotation shaft with an eccentric rotation plate having a drive pin thereon, and a vertically moving rotation cylinder for allowing a dental drill to move in vertical and horizontal directions. The rotation plate and the drive pin are engaged respectively with two portions of the vertically moving rotation cylinder so that the vertically moving rotation cylinder is automatically caused to rotate horizontally and move up and down, to thereby provide an excellent dental treating operation.

Abstract: A bracket has a longitudinal channel adapted to receive a wire arch. A retaining member is rotatably mounted in the bracket body and includes a retaining spider which is angularly movable to first and second retaining positions, in which the retaining spider extends across at least part of the width of the passage. The retaining spider is adapted in the first retaining position to slidably retain a wire arch in the channel and in the second retaining position to clamp a wire arch in position in the channel.

Abstract: In a process for the growing of aquatic animals in a controlled environment wherein water is continuously circulated through a tank, the improvement which comprises introducing fresh water into said tank having an inner wall; at the upper rim sufficiently tangential to said inner wall of the tank and at a sufficient rate to maintain a circular water flow throughout the tank, and discharging wastewater at the lower end of the tank.

Abstract: An artificial porcelain tooth product containing a combination of terbium and cerium salts to produce a desired fluorescence.