Abstract: An embossed article such as a plastic bowl is injection molded between the molding surfaces of an unidirectional mold. The outer molding surface is inclined outwardly from bottom to top and is provided with an engraved area in which the boss is formed. The undercut upper edge of the engraved area is slanted in a manner to provide an inclined lead in surface on the boss. The undercut of the lead in surface is slight enough that the boss is able to release from the engraved area without damage as the mold opens in unidirectional fashion for removal of the molded article.

Abstract: A profile (1) for producing a frame comprises, in one piece, a steel strip which is worked to form a hollow profile and in which undercut longitudinal grooves (2) are made. The longitudinal grooves (2) are delimited by webs (4) which project into the groove openings and have double the wall thickness of the steel strip. In comparison with known lightweight metal profiles, the steel profile has higher strength and rigidity.

Abstract: An injection moulding tool has a mould in two parts which open axially. It produces mouldings with >=1 undercut at the front and back and with two longitudinal sides formed by a mould component which passes through a hole in one part of the mould. The relative positions of these parts and the component are altered to release the undercuts by partly rotating the component about the tool axis, and the operative part of the component at the undercuts extends over a radial angle of 180 degrees max. Simple construction, suitable for any length of undercut and where side cores inclined cores and axially withdrawn cores cannot be used.

Abstract: Differences between the developed photoresist profile and the optical image in the resist is a function of exposure and development conditions. Because of absorption of light in the photoresist and lateral etching by the developer, an overcut profile in the developed image of positive resists is inevitable, even if the distribution of the exposing light is perfectly verical. Intentional overexposure followed with quick development, or the use of highly reflective substrates only minimizes the overcut. This paper describes an approach using a rotating plane wave making a predetermined angle with the optical axis to expose a mask–wafer assembly. This type of illumination produces an undercut optical image which compensates for the absorption and lateral etching effects. It also reduces the coherence in the illumination to give better images. The angle of inclination as well as the exposure–development parameters can be adjusted to manipulate the angle of cutting. Analytical intensity distribution based on geometric optics is given to provide an insight to the dependence of the cutting angle to the beam angle and the exposure–development parameters. PMMA in the deep‐uv wavelength region and AZ1350J in the near‐uv region are used to demonstrate the variation of the cutting angle and the liftoff process.

Abstract: Prodn. of thermoplastics mouldings possessing an undercut or back cut utilises normal shaping moulds for modifying thermoplastics plates. The thermoplastics is shaped, while in the softening range, by a shaping plunger or die on which one or more elastic strips are applied, extending around the die at the level of the desired undercut. These strips may opt. be hollow tubes inflated through a valve and subsequently deflated. Pref. after the undercut has been formed, the strips are removed from the plunger or die and it is separated from the mould and the moulded object. Used partic. for forming through-shaped depressions or grooves, for example in a conical semil finished product. Typical examples include double-walled plastics glazing in skylights, automobile windows, railway carriage windows. The elastic strips or tubes are of silicone rubbers.

Abstract: The fitting is for the electrical insulation of metal pipe lines. Two metal connection sections and an insulation sleeve are pressed together to form a rigid body, one section being socket-shaped. One of the longitudinal facing surfaces of the sections has grooves. After connection, one of the sections is deformed, by pressing, with both sections having truncated-cone shaped contact surfaces. The socket section (1) has a conical undercut bore, while the plug section (2) has a cylindrical external shape, and an internal shape decreasing in size towards the end. After assembly, the plug section is pressed by a mandrel tool against the insulation, into the undercut bore of the socket section, which retains its shape.

Abstract: The construction eelement has undercut connection rails, to engage in tubular undercut grooves of other elements in a construction toy set. The connection rails consist of two semi-shell shaped parallel strips, enclosing a gap between their front edges. The width of the gap corresponds to the difference between the largest and the smallest dimension of the undercut groove. The outer sides of the strips are pointed towards the gap.

Abstract: : During the welding process, changes in arc voltage, travel speed, and heat input can occur without the operator's knowledge. These changes can cause defects such as porosity, slag inclusions, incomplete fusion, and undercut in the deposited weld metal. The cost of locating and repairing these defects can be a major portion of construction costs; welding inspection can constitute 25 to 40% of the weld fabrication cost. In addition, weld defects decrease service life of welded joints. Consequently, it is necessary to monitor the welding parameters to detect, identify, and locate possible defects. A weld monitor with real-time output would aid the inspector in designating suspect areas for non-destructing testing after welding. Further, a real-time weld quality monitor could be used to interrupt welding when defects are occurring thus precluding costly rework. To address this need, the US Army Construction Engineering Research Laboratory (CERL) is conducting research to develop a field-portable real-time weld quality monitor (WQM). (Author)

Abstract: PURPOSE:To obtain sufficient weld-joint characteristics, when T-type or L-type joint is welded using a high output high density beam, by repairing weld defects generated after the welding work at the weld zone on the side of incidence of the beam and on the opposite side. CONSTITUTION:A T-type joint is made of parts 4 and 5 by the electron beam 6 welding, and the weld zone 7 is formed. Hereupon, a part of molten metal spouts out opposite against the direction of incidence of the beam, and forms the molten metal drop 9; as a result, an undercut zone is formed at the corner on the incidence side depending on the lack of molten metal. In case of circumstances, a lack of penetration is caused. For the purpose of efficiently repairing above stated defects at the weld zone and of forming good reinforcement weld, an additional welding is carried out on the corner of above stated weld zone 7 depending on the unfocused electron beam; hereby, the reinforcement weld 11 is formed. Moreover, the filler metal 10 is preferable to be used for the corner where the undercut is caused. For the L-type joint, the welding is performed similarly to above case.

Abstract: A technique has been developed for making comparative evaluations of the adhesion of photoresists to various types of substrates. The technique is based on the use of a fluoride-containing etchant which exaggerates the rate of undercutting of photoresist on silicon dioxide (SiO 2 ) surfaces and thus permits direct microscopic measurement of the relative rates of undercutting that result with various types of SiO 2 surfaces and with various types of photoresist materials. Using the special etchant, the benefits of adhesion promoters such as hexamethyldisilazane are readily demonstrated. An empirical equation is given which approximately describes the shape of the undercut oxide edges, thus allowing a numerical measure of the relative adhesion (that is, resistance to etchant undercutting) of photoresist/SiO 2 composites. A variation of this test can be used to detect nonuniform adhesion across a wafer surface. A photomask with a very-fine-geometry, highly recurrent pattern is used to define the photoresist, after which the wafer is etched. By using an optical microscope, the resultant dielectric/silicon substrate can be inspected very rapidly for localized adhesion variation because of the distinct color difference between areas which have or have not been undercut.

Abstract: The plastics grip for a stamping device has a round body tapering in a droplet shape towards the device and with a flat running in the axial direction. It is in two parts (2, 3) one (2) being a hollow-thin-walled body with an inner coaxial sleeve (4) fitting over a mounting boss, and the other a cap (3) fitting over the body opening, the flat (1) extending as far as the cap. One of the parts has, except near the flat, an undercut axial spigot (6) snapping into engagement with a mating undercut portion in the edge of the other. There being a ramp face in the latter leading to the undercut and sloping in the opposite direction.

Abstract: We describe a photoresist stencil technique that has proven to be quite reliable in the preparation of thin‐film Josephson logic and memory devices. The method employs multiple layers of resist with the top layer providing patterning and the bottom layer spacing the top layer from the substrate and providing an undercut under the top layer. This method has consistently produced uniform undercuts over ∠1 in. (∠2.54 cm) sample dimensions and has been used to produce micron‐sized patterns.