Abstract: A weftless warp of yarns being drawn and wound on a beam is fed through a tension detector, located prior to the drawing step and responsive to tension in any of the yarns equalling a predetermined non-zero level, for stopping the process. This prevents damage to or breakage of a yarn which might have become snagged in the warp source.

Abstract: A method for molding an annular lip type shaft seal 10 of the type having an annular elastomeric shaft seal element 12 and a resin liner 14 (preferably polytetrafluoroethylene) integrally molded therewith and bonded thereto, including providing a step or shoulder 36 on the mold core 26 to prevent the resin liner 14 from flowing axially beyond a predetermined location during molding. The method includes providing a certain range of acute angles ".alpha." between the shoulder surface 42 and the liner forming surface 38 of the mold core surface 34, and a certain range of shoulder heights "d" relative to the liner thickness "t", for various values of the initial viscosity of the elastomeric preform 18. The percentage of rejects due to undesired flow of the resin liner 14 during molding has been greatly reduced.

Abstract: A method for forming a connecting sleeve having an internal groove at the end section of a tube made of crystalline or partially crystalline thermoplastic material in which the end section is heated to the deformation temperature and then is axially upset in a heatable device which defines an annular gap until the annular gap is filled. This increases the wall thickness of said end section, which is then shaped to form the connecting sleeve during axial displacement in a mold. The end section is heated to a processing temperature within the range of the deformation temperature and up to the crystalline melting temperature. In the initial step in the heatable device the application of the first axial upsetting force is such that the upsetting begins at the front end of the end section and continues until the annular gap in the heatable device is filled.

Abstract: This invention relates to biaxially oriented polypropylenefilm and method for its production. The method for its production comprises a step of fusing and extruding polypropylene in a sheet form, a step of cooling and solidifying a formed polypropylene film, a step of preheating it and a step of orienting it in a longitudinal direction and finally in a lateral direction, characterized in that a longitudinal orientation of the polypropylene film is carried out by at least a double-stage process. The polypropylene film thus biaxially oriented has improved rigidity.

Abstract: Polyimide film is manufactured by solvent casting onto a film-supporting surface. A solution of polyimide resin is dissolved in hot organic solvent to provide a casting dope. The film is coagulated by contacting an aqueous medium, substantially replacing the organic solvent in the film with water. Orienting the water-containing film and drying the oriented film to remove water produces a substantially homogeneous polyimide film having high electrical resistance, flexibility and strength.

Abstract: A tabletting machine having a ring-shaped die table rotatable about a generally upwardly extending axis and having dies arranged at a die surface. Punches supported in the die table and reciprocably driven with respect to the dies co-operate with punches semi-rigidly mounted on a rotatable hub to form and eject tablets from the dies. The hub is rotated to move the punches mounted thereon in a circular path to enter and exit the dies in a predetermined sequence. Individual pump means associated with the punches in the die table and means for catching and extracting loose tabletting material falling from the dies serve to reduce contamination of the many parts of the machine by the tabletting material.

Abstract: When a pair of plastics sheathed glass optical fibres (1, 2) is joined by a fusion splice there is a length of bare fibre between where the original sheathing of one fibre terminates and where that of the other begins. This gap is filled with reinstatement sheathing (5, 5b) which is fused to the original sheathing using a length (4) of heat-shrink tubing as a mould. The heat-shrink tubing is then removed to leave a smooth profile for the spliced fibre.

Abstract: A fixture for evenly distributing a predetermined clamping force about annular mating surfaces of a two-piece lens casting mold for avoidance of unwanted cast lens prism and/or edge flash.

Abstract: An electrical socket connector is detachably connected to a post terminal having two axially arranged contacts. The socket connector comprises a one-piece ceramic connector body having a pair of tiered terminal cavities each of which is closed at one end and has a central guide rib. Each cavity retains an appropriately sized channel-shaped contact terminal and communicates with a socket for receiving the post terminal lead wires which project through a boot for sealing the open end of the connector body.The one-piece connector body is made by dry pressing ceramic powder into a machineable preform with terminal cavities. The preform is then drilled to provide the socket and retention shoulders in the longitudinal ribs.

Abstract: A conforming valved cervical cap assembly is provided with an elastomeric inner layer molded and cured in situ adjacent the exocervical surface of a cervix uteri. The inner layer is wettable, nonporous and matingly fits and resiliently complements the exocervical surface. In order to prevent the molding material from clogging or otherwise impairing operation of the valve, a valve cover is detachably connected to the valve during molding and curing.

Abstract: A method by which a previously molded hollow plastic retainer having an open end portion necessitated by the need to withdraw a mold core therefrom may be embedded in a molded trim article with the open end beneath the surface and yet the molding material is prevented from flowing through the open end portion and filling the hollow of the retainer.

Abstract: This invention relates to a method for correcting visual refractive errors of the human eye. In this method, a contact lens is fitted to the patient's eye, the lens being oxygen permeable, wettable, and having an oxygen permeable crosslinking agent.

Abstract: A method of making a photoflash device wherein the device includes a plastic substrate, lamp-firing circuitry located on a first surface of the substrate, a Mylar disconnect switch also secured to the first surface of the substrate and electrically joined to the lamp-firing circuitry, at least one electrically activated photoflash lamp located above the Mylar switch for activating said switch upon ignition thereof, and a solid, light-transmitting polymer located about and encapsulating the glass envelope of the lamp. A thin, light-transmitting polyester member is located over the Mylar switch prior to pouring of the liquid casting resin which eventually forms the solid polymer protective encapsulant. The polyester member serves to prevent contact between the resin and switch and thus enables close placement of the lamp's envelope and switch, said placement thereby assuring proper activation (e.g., severance) of the switch.

Abstract: Method for constructing a three-dimensional film forming structure for imparting a selectively apertured three-dimensional pattern to a heated plastic material which is either fed in film form from a supply roll or extruded as a melt directly onto the surface of the forming structure and subjected to a fluid pressure differential while in contact with its surface. The completed structure comprises a stacked laminate of initially imperforate planar sheets having continuous patterns of apertures formed therein and at least one initially perforate selectively apertured planar sheet located beneath the uppermost continuously apertured sheet. The apertures formed in the initially perforate selectively apertured sheet coincide with the portions of the plastic web to be apertured. The completed laminate forming structure is preferably tubular in shape so as to facilitate continuous plastic web processing against its outermost surface.

Abstract: In accordance with the present invention, there is provided an improved arrangement for and method of electrically testing a cord-set during the molding of the male plug and female receptacle to the opposite ends of the insulated electric cord. In order to accomplish this, the mold for forming the molded plug and receptacle is provided with suitable contacts which upon the closing of the mold automatically establish electrical connections between the terminals of the cord-set and circuits in testing apparatus. These tests consist of checking for continuity in each conductor and for shorts between conductors or terminals and a skin ground test for the purpose of detecting stray strands of wire or any current carrying object that would carry current to the outside surface of the molded plug or receptacle.

Abstract: In order to make a non-planar plastics material article, a starting material has at least one ring of holes or depressions and is pressed so that the part which is within the ring is moved generally at right angles to the plane of the ring with respect to the part which is outside the ring, thereby stretching, into orientated strands, zones between adjacent holes or depressions in the ring; in the finished article, the strands interconnect the two parts.

Abstract: Extrusion-cast films of high molecular weight, linear low density ethylene copolymers which inherently have high block and low slip characteristics are compounded with a minor amount of a secondary fatty acid amide and a finely-divided natural inorganic, e.g., silica, before being extrusion-cast as a thin film, the additives serving to substantially reduce the block and increase the slip characteristics of the film.

Abstract: A method and means for contructing a three dimensional contour relief map, or the like, which comprises a housing having the opposite ends thereof open and having a plurality of upright side-by-side tubes disposed therein, the lower open end of the housing being in communication with a liquid reservoir, the lower end of each tube being open to the liquid through a check valve for controlling the admission of the liquid into the interior thereof, and the upper end of each tube being open, a pantograph type tracing or scribing instrument having a tracer for movement along the contours of the map being transformed into the three dimensional scale model and having an arm member movable over the open upper ends of the tubes simultaneously with the scribing of the map contour lines, a vacuum source in communication with the open upper ends of the tubes through the arm passing thereover for creating a selected pressure differential between the interior of the respective tube and the ambient pressure acting on the su

Abstract: The invention relates to a fabrication method for molding a contact lens with the required optical qualities.This method consists in designing a mold (1, 2) of high thermal inertia, which is transparent to, or little absorbing the electromagnetic microwave frequencies between 10.sup.6 Hz and 10.sup.11 Hz, in developing a base composition from polymerizing double-bond monomers which are absorbing with respect to the above microwaves, and in ensuring the polymerization of the composition within the closed mold by irradiation with the above cited electromagnetic waves at a power density suited to keep the temperature at the mold level approximately below 40.degree. C.

Abstract: An improvement in molding devices is disclosed which has particular application in the formation of round rubber objects. The cavity cups in one mold plate are made of greater than hemispherical dimension whereby all of the balls will remain in one of the plates when the plates are separated. A flash removal system is also disclosed.