Abstract: A propeller shaft includes male and female shafts, each having at one end a yoke and at the other end a spline sliding portion. At least one of these shafts is wholly made of a hollow tube and its one end is worked to form an integral yoke and the other end is plastically worked with a die to form an integral spline sliding portion. A separate yoke may be welded to the hollow tube. The spline sliding portion thus formed has spline teeth of an integer number within the range of numerals obtained by multiplying the numeral indicating a larger spline diameter in mm by 0.12 to 0.25. The spline teeth has a spline tooth root angle within the range of 90 to 120 degrees enclosed between side faces of adjacent spline teeth. The propeller shaft reduces man-hour for producing it to improve the production efficiency and hence reduce its cost.

Abstract: A screw extending through the knuckles of the arm hinge of a pair of spectacles and having a threaded end screwed into one knuckle. The part of the screw that extends beyond said knuckle has an annular groove recieivng a circlip which engages the outer surface of the knuckle to prevent inadvertent loosening of the screw with its head held in engagement with the knuckle. The size of the annular groove receiving the circlip is such that said groove is partially located within the knuckle. As a result, should the assembly become loose, it can be tightened again by replacing said circlip with another slightly thicker circlip.

Abstract: An instrument for boring dental radicular canals in which the conicity of the active part of the tapered stem of the instrument is not constant but the angle of its opening is greater at its rear portion, positioned beyond the diameter D.sub.9, than the angle of opening of its front portion positioned between its end and the diameter D.sub.9 so that a dental canal bored with the instrument has a bell-mouthed shape.

Abstract: A twist dispensing closure including a spout part matingly engageable with a base part adapted to be secured to the neck of a container holding product to be dispensed. The base part includes upstanding cam followers for engagement with ramps formed by channels provided on the inner surface of the spout part. Rotation of the spout part with respect to the base part causes the cam followers to ride on the ramps and thereby move the spout part away from the base part from a closed condition of the spout to an opened condition, thereby permitting dispensing of product through the spout.

Abstract: A press-in contact includes a connection portion to be connected to a mating connector, a press-fitting portion to be fixed in a cylindrical through-hole of a printed circuit board by press-fitting, and a contact portion for introducing the press-in contact to the printed circuit board. The press-in contact further includes a positioning portion. The positioning portion has two plate-shaped pieces each having a surface to be urged by a jig for press-fitting operation and a connection part for connecting the plate-shaped pieces and the connection portion. The connection portion is formed in a substantially J-shape by bending, and center axes of the connection portion and the positioning portion are shifted from each other. As an alternative, the plate-shaped pieces are formed in a C-shape in cross-section, and center axes of the connection portion and the plate-shaped pieces of the positioning portion are shifted from each other.

Abstract: The length of the active part of each drill of the set is inversely proportional to the diameter of the cutting edge of each drill, that prevents the drills of the set being too much engaged in the coronary canal, since the depth of the working depends with precision from the used drill.

Abstract: An interface connector is disclosed which is inexpensive to manufacture and easy to assemble and able to maintain a sufficient strength of hooks when being engaged with a mating connector. An insulator of the connector covered with a shell includes flanges. Each of the flanges is provided with an engaging aperture having a size allowing a hook to be inserted thereinto in the surface of the flange on the fitting side with a mating connector and a further engaging aperture having a size allowing an earth plate to be inserted thereinto in the end surface of the flange. The two engaging apertures are connected each other in the flange. The hook is provided with anchoring portions engaging the earth plate. The earth plate is also provided on its inner end with engaging portions engaging the hook. The hook and the earth plate are connected to each other in the two engaging apertures.

Abstract: Regular rhombic dodecahedrons having faces with two aspects of two different kinds, each belonging to a same family, one by a bare surface, the other one by a shaded surface, are piled on a base having nests allowing those polyhedrons to be placed on top to build a composed pyramid. The general configuration of the visible faces of one kind and of the other kind will respond to specific rules of the game.

Abstract: A driving shaft having splined male and female shafts. The spline tooth pattern of the male shaft seen in a cross-section comprises an inclined portion substantially similar to those of a symmetrical spline tooth pattern of a conventional male shaft, and an outwardly convex and gently curved portion starting from the outer end of the inclined portion and terminating in a smaller diameter portion at the bottom of the tooth pattern. The radius of the smaller diameter portion and the tooth width at the bottom of the tooth pattern are larger than those in the symmetrical spline tooth pattern of the conventional male shaft, thereby obtaining an improved driving shaft to transmit greater rotating torque. The spline sliding portion of the female shaft is formed from a hollow tube by press-forming in a manner that the outer diameter of the press-formed portion is larger than that of a hollow blank tube, thereby increasing the torque transmission diameter to reduce surface pressure resulting in prolonged service life.

Abstract: A drumstick having a striking portion of conventional cylindrical configuration and terminating at a striking tip, and a handle portion of generally triangular cross-sectional configuration. The triangular configuration of the handle portion can be formed by cutting away part of the drumstick, or by installing a sleeve member over the handle portion of a conventional drumstick, the sleeve member having a triangular external cross-sectional configuration.

Abstract: The central part of the instruments of the boring set, prior to the portion having the cutting edges, has a section of a polygonal shape. The lateral faces of the central part are either convex, for the instruments of small diameter, plane for the instruments of middle diameter and concave for the instruments of largest diameter, in such a way that the curve of the bending moments of the instruments of the set is substantially rectilinear. Thus the variation of the bending moments of the instruments is linear, while, in previously known sets of instruments, the curve is exponential. Hence, the flexibility of the instruments of the set is satisfactory for the entire set of instruments, while; in the known conventional sets, if previously flexibility of the small instruments of the set is satisfactory, the instruments of largest diameter will be too rigid, and vice versa.

Abstract: A clasp with a locking flap (8) hingedly mounted between the arms (3a, 3b) of a yoke-shaped member (3) by means of a pin (9) extending through one portion (8a) of said flap (8). Said portion (8a) is shorter than the distance between the two arms (3a, 3b) so that the flap (8) is transversely translatable. The pin (9) has a straight portion (9c) partially inserted into a correspondingly shaped recess (13) in one arm (3b). The pin (9) is thus prevented from rotating about its own axis. The passage (14) in said portion (8a) of the flap which receives the pin (9) has an inlet (14a) shaped to fit said portion (9c) of the pin (9). A coil spring (15) on the pin (9) biases the flap (8) towards said portion (9c) of the pin (9). When the flap (8) is in the folded down or locking position, said portion (9c) of the pin (9) is inserted into the inlet (14a) of the passage (14), thereby locking the flap (8).

Abstract: A set of instruments for boring of radicular dental canals, in which the diameter D1 of each instrument, measured at the root of the pointed end portion thereof, varies according to a geometrical progression as well as the diameter D2 of each instrument measured at the root of the cutting edges. Hence, the variation is more pronounced for the diameters D2, larger than the diameters D1, than it is for the diameters D1. The conicity of the stem of the instruments increases in this manner from one instrument to another, so as to permit a the dentist to form the radicular canals with a specially funnelled shape which is best suited for some obturations, especially those to be treated with gutta-percha.

Abstract: A press-in contact has a press-fitting portion which is press-fitted in a cylindrical through-hole of a printed circuit board, thereby fixing the press-in contact to the circuit board. The cross-section of the press-fitting portion of the press-in contact includes a U-shaped inner edge and an outer periphery having two arc parts and a straight part therebetween. The circular part of the U-shaped inner edge at its bottom and the two arc parts of the outer periphery are in eccentric relation of shifted centers. The thickness of the arc parts is progressively thinner toward the open ends of the U-shaped inner edge, and a circumferential length of the arc parts of the outer periphery contacting the through-hole of the printed circuit board is as long as possible. With the press-in contact thus constructed, no whitening occurs in the proximity of the through-hole of the printed circuit board even if the holding force for the contact is more than 5 kg.

Abstract: A set of instruments for boring dental radicular canals in which the conicity of the rear part of the set positioned beyond the diameter D.sub.9 of the instruments, increases more for the first instruments of the set than for the last ones. The conicity of the front part of the instruments does not increase much for the first instruments of the set, but does increase for the last ones. Hence, while using successively the instruments of a set, the dentist bores first the coronary portion of the tooth, then its medium portion and then its apical portion. The end part of the instruments, between the point thereof and their diameter D.sub.3, situated at 3 mm from the point, is provided with one or several grooves for elimination of the dental scraps, but which have no cutting edges so that this part of the instruments functions only for their guidance.

Abstract: Peel control for an off-contact printing press. The peel control includes a clutch and a linkage assembly synchronized in its peeling action in a printing stroke with a conventional carriage assembly mounting the squeegee and flood bar. In the printing stroke, the clutch is engaged to effect pivot of the master frame relative to the horizontal printing bed of the press and synchronized with the carriage assembly movement to effect peeling of the print screen in such a print stroke. Upon completion of the print stroke, the clutch is disengaged to permit return of the master frame to its horizontal position relative to the print bed. Thereafter, the flood bar is moved in its flood stroke across the print screen, which will be in a horizontal position relative to the print bed also, to the initial position for the succeeding print stroke.

Abstract: An electrical connector includes a plurality of contacts, an insulator for receiving the contacts, and guides provided at both ends of the insulator's lengthwise direction. The connector includes push bars inserted in the guides of the insulator, respectively. Each of the push bars has at its one end an anchor portion for engaging a circuit board or a mating connector, an engaging portion at the other end, and a spring piece between the anchor and engaging portions. The connector further includes cams disposed in mounting portions provided at bottoms of the guides at both the ends of the insulator, respectively. Each of the cams has an anchor portion at its one end engageable the engaging portion of the push bar and has a support consisting of pivot pins on the side of the other end for pivotal movement of the cam. The engaging portion of each the push bar is connected to the anchor portion of one of the cams.

Abstract: An electrical connector having a locking member which includes at one end an anchoring part shaped for hooking a mating connector, an engagement part to be secured to one of projections provided on both sides of a shell enclosing a main connector body, and at the other end a knob portion having a leaf spring. The engagement part is positioned between the anchoring part and the knob portion. The engagement part has a protrusion near to the center of the width of one end adjacent the knob portion, and two plate pieces on both the sides of the protrusion. Each of the plate pieces has a free end in the form of a resilient cantilever directing toward the protrusion. The spacing between the free ends of the two plate pieces is less than the width of the projection of the shell.