Abstract: An efficient method is proposed for the utilization of heretofore useless extremely fine fluffy silica particles obtained as a flue dust in the flame-hydrolysis of vaporizable silicon compound in an oxyhydrogen flame in the manufacturing process of fused silica glass. The method comprises the steps of (a) uniformly mixing the silica particles with water, (b) drying the wet mixture under specified conditions to give dried cakes of the silica particles, (c) disintegrating the dried cakes into porous silica beads having an appropriate particle diameter, (d) semi-sintering the porous silica beads at 800 to 1300° C. and (e) vitrifying the semi-sintered silica beads at 1350 to 1550° C. into vitrified poreless silica glass particles which can be used as a base material for the production of fused silica glass articles.

Abstract: Opaque silica glass having a density of 2.0 to 2.18 g/cm.sup.3, sodium and potassium elements concentrations in the silica glass of each 0.5 ppm or less and an OH group concentration of 30 ppm or less, and containing bubbles which are independent bubbles having the following physical values: a bubble diameter of 300 .mu.m or less, and a bubble density of 100,000 to 1,000,000 bubbles/cm.sup.3, and a production process for opaque silica glass, including: filling quartz raw material grain having a particle size of 10 to 350 .mu.m in a heat resistant mold, heating it in a non-oxidizing atmosphere from a room temperature up to a temperature lower by 50 to 150.degree. C. than a temperature at which the above raw material grain is melted at a temperature-raising speed not exceeding 50.degree. C./minute, then, slowly heating it up to a temperature higher by 10 to 80.degree. C. than the temperature at which the quartz raw material grain is melted at the speed of 10.degree. C.

Abstract: An objective of the present invention is to provide a fuel injection pump wherewith, in addition to main injection, pre-injection is made possible in the vicinity of top dead center in the exhaust stroke, and wherewith, by regulating the pre-stroke, defined as the stroke from bottom dead center of a plunger 2 to the commencement of fuel line pressurization, it is possible to freely control both the pre-injection volume and the pre-injection timing relative to the main injection. Attention having been given to the combining of a pre-stroke varying mechanism together with a two-stage injection mechanism, the present invention is a fuel injection pump that is made so that a pre-stroke is regulated by changing the relative positions, in the axial direction, of a plunger 2 that sends fuel under pressure and a control sleeve 3 that fits around the outside of the plunger 2 so as to slide freely thereon.

Abstract: The present invention provides a fuel injection pump plunger whereby it is possible to avoid deformation of the timing sleeve 11 in the fact of increased fuel pressure, to ensure no-injection state even with elimination of the furrow, and to prevent secondary injection. It results from the realization that it is possible to replace the furrow with an aperture with which the spill port can connect in line with the movement of the plunger 20, and is wherein an aperture (horizontal aperture 21) is provided below and separate from said inclined lead 10, this aperture 21 being such that it is not only connected with said central fuel passage 8, but in the no-injection position of said control rack 13 allows said spill port 12 to engage either with this aperture 21, with said inclined lead 10, or with both of them, the area of the aperture when they engage being the same as the area of said central fuel passage 8.

Abstract: A process for producing opaque silica glass in which a quartz raw material grain having a particle size of 10 to 350 .mu.m is filled into a heat resistant mold, the quartz raw material grain is heated in a non-oxidizing atmosphere from a room temperature up to a temperature lower by 50.degree. to 150.degree. C. than a temperature at which the above raw material grain is melted at a temperature-increase speed not exceeding 50.degree. C./minute, then, slowly heated up to a temperature higher by 10.degree. to 80.degree. C. than the temperature at which the quartz raw material grain is melted at the speed of 10.degree. C./minute or less, and the heated quartz raw material grain is further maintained at the temperature higher by 10.degree. to 80.degree. C. than the temperature at which the quartz raw material grain is melted, followed by cooling down to the room temperature.

Abstract: A prestroke controller 31 for an engine fuel injection pump 30 utilizes a magnetic coupling 26 and, by taking advantage of the fact that the secondary side (driven side internal magnet) of the magnetic coupling can be controlled to a desired position without being driven by force from a flyweight 11 on the primary side (driving side external magnet), not only secures speed timer characteristics but also provides a greater degree of freedom in determining the injection timing advance characteristic. The prestroke controller 31 includes the magnetic coupling 26 as a member of a displacement transfer section provided between the flyweight 11 and the timing control rod 6 and also includes an add-on device 36 for injection timing advance adjustment which can be engaged with or disengaged from the timing control rod 6 and is capable of controlling the prestroke independently of the magnetic coupling 26.

Abstract: A fuel injection pump for an engine comprises a magnetic coupling 37 straddling a partition 36 for connecting a timing control rod 6 and a displacement transfer section 34 of a governor so as to enable efficient transfer of rotational force from the displacement transfer section to the timing control rod without need for an oil seal therebetween, and a prestroke controller for the fuel injection pump 131 includes an injection advance adjustment add-on device 136 for conducting prestroke control independently of the magnetic coupling and thereby provide greater freedom in establishing injection timing advance characteristics by enabling injection timing control in response to temperature or load and/or a safety mechanism 237 for ensuring operation of a governor mechanism 20 based on movement of a flyweight 11 even if the magnetic coupling should stick.

Abstract: A prestroke adjustment mechanism for a fuel injection pump comprises a U-shaped lever provided on the outer surface of the pump housing for rotating a timing control rod of the injection pump and a rotation limit pin provided on the same outer surface for limiting the rotation of the U-shaped lever. The timing control rod is linked with a control sleeve on the pump plunger for adjusting the prestroke. By limiting the rotation of the U-shaped lever, the rotation limiting pin limits the height of the control sleeve for ensuring establishment between the top of the control sleeve and the bottom of the upper section of the plunger barrel of a gap for dissipating the force of the spill jet during fuel spill. As a result, the downward force of internal turbulence produced by the spill jet is dissipated, thereby preventing the control sleeve from slipping downward and ensuring stable and reliable prestroke adjustment.

Abstract: A process for preparing a vinyl chloride copolymer which comprises polymerizing a vinyl chloride monomer or a mixture of a major proportion of a vinyl chloride monomer with a minor proportion of a copolymerizable monomer and at least one crosslinking agent selected from polyhydric alcohol diglycidyl ether diacrylates and dimethacrylates. The crosslinking agent is added to the reaction system after polymerization of the vinyl chloride monomer or the mixture proceeds to a certain extent. By this, the resultant copolymer has good processability and good mechanical and electric characteristics.

Abstract: A vinyl chloride copolymer is produced by copolymerizing vinyl chloride monomer or a monomer mixture comoposed of vinyl chloride monomer and copolymerizable monomer, with one or more than one kind of cross-linking agent selected from polyhydric alcohol diglycidyl ether diacrylate and dimethacrylate. The vinyl chloride copolymer has good moldability and can be made into moldings having good matte finish surface and also good permanent compression set resistance, creep resistance, heat resistance, and electrical properties.

Abstract: A composite polymeric material having a high permeability to oxygen is proposed comprising a vinyl chloride moiety, an organosilicon moiety and, optionally, a third polymeric moiety. Such a composite polymeric material can be prepared in several ways including copolymerization of vinyl chloride monomer, a polymerizable organosilicon compound and, optionally, a third monomer, graft-polymerization of a polymerizable organosilicon compound on to a polyvinyl chloride resin, graft-polymerization of vinyl chloride on to an organopolysiloxane, graft-copolymerization of vinyl chloride and a polymerizable organosilicon compound on to a third polymer and blending of the respective polymeric components.

Abstract: The invention provides a formulation of a vinyl chloride resin-based composition suitable for preparing floppy disc jackets having high heat resistance with a Clash-Berg temperature of 75.degree. C. or higher comprising, as the essential components, (A) a copolymer of viny chloride with a N-substituted maleimide as the comonomer, optionally in combination with a homopolymeric polyvinyl chloride resin, (B) an impact-strength improving agent which is preferably a vulcanizable synthetic rubber and (C) carbon black.