摘要:
Extrusion start-up or peak pressure is reduced by initially commencing extrusion of the billet through a multiple aperture die and then closing off all but one of the said apertures in the die.
摘要:
An M-shaped electrical connector is fabricated by initially forming one or more elongated slots in a flexible planar strip of electrically conductive material. The slotted strip then is bent into an M-shaped configuration so that each slot defines spaced center or intermediate legs spaced apart in a first direction for receiving first sections of one or more electrical conductors therebetween with a press-fit, and so that end portions of the slotted strip define outer legs spaced apart in a second direction perpendicular to the first direction for receiving and aligning second sections of the electrical conductors therebetween with a press-fit. Each slot in the planar strip may be enlarged intermediate its ends to define a flared entrance to the slot when the strip is formed into the M-shaped configuration. Adjacent ends of the conductors also may be beveled, and the outer legs of the connector may be formed with flared portions, to facilitate insertion of the electrical connector over the ends of the electrical conductors.
摘要:
A pulse corrector circuit is disclosed for responding to input telephone dial pulsing over a range of input pulsing speeds and for providing output dial pulsing at the same speed as the input pulsing but with a substantially constant output duty cycle, or break-to-make percentage ratio as such a duty cycle is referred to in the art. The output duty cycle is determined jointly by a fixed interval timer and a variable interval timer. The variable timer includes a resistance-capacitance time constant network for which an asymptote voltage is provided so that during the variable interval the capacitance changes its voltage toward a prescribed voltage at a rate determined jointly by the time constant and by the value of the asymptote voltage. The fixed timer is controlled by the input pulsing speed to adjust the asymptote voltage to an initial low value and then to a high value sooner or later according to faster or slower input pulsing speeds so that the capacitance voltage reaches the prescribed voltage sooner or later according to input pulsing speed. The total variable time interval prescribes the duration of the output break interval; and, the output make interval is controlled by the amount of overlap, if any, of the fixed and variable intervals. The pulse corrector is provided with split pulse guard and supervision control circuitry for guarding against input transitions of too short durations to represent legitimate signals and for passing steady-state supervision from input to output.
摘要:
A limiting circuit comprises an operational amplifier that reverse biases a limiting diode connected to a load when a signal potential applied to the load through a dropping resistor is less than a reference potential, and forward biases the limiting diode when the applied signal potential is greater than the reference potential, thus preventing the potential applied to the load from exceeding the reference potential.
摘要:
In crossover circuits, air-insulated crossover conductors on a substrate for hybrid integrated networks are solidly supported to prevent electrical shorts between the crossover and any underlying conductors. In doing this, a resin is applied over the surface of the substrate. Capillary attraction forms an agglomeration of the resin about each crossover conductor. The resin is then hardened to form supports for the crossover conductors. Subsequent etching and rinsing removes all of the resin from the surface of the substrate but leaves it under the crossover conductors to continue supporting them. With the resin so removed, semiconductor chips may be bonded to terminal areas on the substrate.
摘要:
The capacitance and diameter-over-dielectric of successive sections of a conductor having a layer of cellular plastic insulation extruded thereon are monitored continuously. The monitoring provides a continuous indication of the capacitance and the diameter with respect to the percent expansion of the cellular plastic insulation and the weight of the insulation per unit length of the conductor. This facilitates the regulation of process variables to maintain the capacitance and diameter-overdielectric within acceptable ranges of values.
摘要:
In transfer molding thermosetting polymeric materials, a first preform of first thermosetting polymeric material having a volume substantially equal to the volume of the die cavities is placed in the transfer chamber adjacent the runners. A second preform of second thermosetting polymeric material cheaper than the first polymeric material is placed in the transfer chamber above the first preform. The transfer chamber is pressurized and the second preform is deformed and pressurizes and deforms the first preform and causes the first thermosetting polymeric material to flow through the runners into the die cavities. After curing, the molded articles consisting of first thermosetting polymeric material are removed from the die cavity, and scrap cull and runner consisting substantially of cheap second thermosetting polymeric material are removed from the mold runners and the bottom of the transfer chamber. Thus, considerable economies are effected. The material of the second preform is selected for certain physical properties. Various means are shown for loading the transfer chamber.
摘要:
First and second concentric insulating sheaths of plastic materials are formed continuously around a filamentary core advancing longitudinally through an extrusion chamber. The core is passed axially through a tapered entrance portion and a coaxially aligned tapered throat portion formed in a separable die disposed in the chamber. Fluent plastic material for the first sheath is delivered from a main extrusion bore, impinging on the core circumferentially at the entrance portion of the die, the flow thereof being developed as it passes into the throat portion thereof. Fluent plastic material for the second sheath is delivered from an auxiliary extrusion bore flowing through a plurality of dividing channels formed in the die and radially inward at a plurality of circumferentially spaced points around the die axis into an annular manifold or reservoir where the fluid pressure of the plastic achieves a steady state condition. The plastic is forced from the manifold circumferentially, flowing in a frustoconical channel formed in the die which terminates in an annular fluid inlet formed in the throat portion of the die to impinge circumferentially around the first sheath, forming both sheaths simultaneously around the core.
摘要:
One or more reference beams from a low-power HeNe laser are multiplexed onto the optical path of a pulsed or Q-switched highpower YAG laser and thereby suffer the same deflection in galvanometer-type deflection apparatus used to deflect the main beam as does the main beam. The reference beams are next split off, prior to the impingement of the YAG beam on the workpiece to be machined, and passed through reference grids. After the beams pass through the reference grids, photodiodes generate signals which can be used to determine precisely where the YAG beam will impinge upon the workpiece when next energized.
摘要:
Modes are filtered in an optical waveguide by selecting and providing a periodic variation, such as a surface corrugation or a refractive index variation, in a filter region in the waveguide. The filter region diverts light in an unwanted mode from the propagation axis by scattering or reflection. Both planar waveguide filters and fiber-optic filters are disclosed.