Abstract: An explosion-preventing suspension insulator includes an insulator body and a metal cap and a metal pin both being bonded to the insulator body by means of cement. A synthetic resin based electrical insulating film having a Young's modulus of elasticity of from 20,000 to 80,000 kgf/cm.sup.2 is provided in a specific thickness on the inner surface of the metal cap and the outer surface of the metal pin at a portion where the metal pin is buried into the cement. The preferred thickness of each electrical insulating film is from 600 to 1,500 .mu.m.

Abstract: An electrolytic corrosion resistant insulator includes an insulator body having a cavity therein and a metallic pin having a portion located within the cavity and secured therein by cement. A sacrificial anode surrounds the pin at an intermediate portion thereof and protrudes radially from the pin. Part of the sacrificial anode is covered by the cement. An electric insulating film of a synthetic resin is lamination-attached to the pin and covers substantially the entire outer surface of the portion of the pin which is secured within the cavity by the cement. The electric insulating film also covers approximately half of the upper portion of the sacrificial anode. The electric insulating film is free from pin holes and has a thickness between 200 and 600 micrometers.

Abstract: A water-soluble film or sheet made of a polyoxyalkylene compound having an average molecular weight of at least 50,000 produced by linking chains of a polyether having an average molecular weight of at least 3,000 and an oxyethylene unit content of at least 70% by weight with each other through ester linkages by reaction of the polyether and a polycarboxylic acid, its anhydride or its lower alkyl ester. The film or sheet is also soluble in organic solvents and has properties comparable or superior to known water-soluble polymer films or sheets.

Abstract: A process for preparing polyoxyalkylene high molecular weight compounds having an average molecular weight of more than 20,000 and being soluble in solvents and moldable by addition-polymerizing ethylene oxide alone or a mixture of alkylene oxides containing ethylene oxide to an organic compound having at least 2 active hydrogen groups to produce a polyhydroxyl compound having an average molecular weight of not less than 1,000, and esterifying the polyhydroxyl compound with a polycarboxylic acid, its anhydride or its lower alkyl ester.

Abstract: A process for the stereospecific polymerization of .alpha.-olefins which comprises polymerizing an .alpha.-olefin with a catalyst comprising (A) the reaction product of a magnesium compound and a titanium compound and (B) an organo-aluminum compound. Component (A) is prepared by reacting a (i) magnesium compound of the formula Mg(OR.sup.1).sub.n X.sup.1.sub.2-n wherein R.sup.1 contains from 1 to 10 carbon atoms and is an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group, X.sup.1 is a halogen atom, and n is a real number of from 1.0 to 2.0, with (ii) at least one halogen-containing compound selected from the group consisting of halogenated hydrocarbons, oxygen-containing halogenated hydrocarbons, halogenated thionyls, halogen-containing phosphorus compounds and halogen-containing nitrogen compounds, and (iii) an oxygen-containing titanium compound of the formula Ti(OR.sup.2).sub.4 wherein R.sup.

Abstract: A small acoustic device is provided with a housing, a first electrically actuated vibrating plate and a second vibrating plate. A support member cooperates with the housing for mounting the periphery of the second vibrating plate to the housing to define therewith an airtight chamber. The support member also supports the periphery of the first vibrating plate in the airtight chamber with a gap between the two vibrating plates and air chambers on either side of the second vibrating plate. In this way, the barometric pressure in the two air chambers on either side of the second vibrating plate are equivalent and the device is both waterproof and independent of ambient temperature changes.

Abstract: An electro-magnetic type electric acoustic transducer comprising an exciting portion consisting of a back plate mounting a permanent magnet and a magnetic core winding an exciting coil therearound, a vibrating plate arranged opposite to said exciting portion leaving a certain space, and a vibrating plate supporting member which supports the periphery of said vibrating plate, characterized in that the resonance frequency of the vibrating plate is reduced while maintaining sound pressure by providing an air hole at a part of said plate or said vibrating plate supporting member.

Abstract: Crude liquid polyether-polyols containing an alkaline catalyst are purified by the steps of:neutralizing said crude liquid polyether-polyol with a mineral acid having a dissociation constant of greater than 10.sup.-3 at 25.degree. C.distilling off water from said liquid, and filtering the same. The improvement resides in the step of adding a hydrate of a metal salt of said mineral acid to the liquid polyether-polyol at a stage before the distillation step for promoting the crystal growth of a salt formed from said alkaline catalyst by the neutralization.

Abstract: An alarm wristwatch comprises a watchcase having a back with an inclined peripheral portion and a watchband attached to the watchcase at opposite sides. A transducer for generating an alarm signal faces a cavity provided in a rear portion of the watch case. A plurality of sound holes provided in the inclined peripheral portion of the watchcase back open into this cavity. The second holes are located within an angle of 45.degree. on either side of the longitudinal center line of the watchband so that they are not blocked or muffled by the arm of the wearer. The cavity and sound holes are so proportioned as to constitute a Helmholz resonator by which the sound produced by the transducer is intensified and efficiently transmitted to the exterior of the watchcase.

Abstract: An alarm watch has an electro-acoustic transducer with a sound releasing cavity containing a vibrating plate for releasing an audible alarm sound. The surface of the vibrating plate exposed to the open air is treated with a water-repellant material having the property to shed or repel water so that when water enters into the sound releasing cavity and wets the vibrating plate, the vibrating plate readily throws off the water thereby obtaining rapid recovery of the alarm sounding function.

Abstract: A miniature electronic buzzer for an electronic watch has two vibrating plates with a sealed space between them forming an air spring. One of the vibrating plates carries an amarature which is acted upon by an electromagnetic to vibrate said plate. Vibration is imparted to the other vibrating plate by the air spring. The two vibrating plates and coupling air spring constitute a vibrating system having two resonant frequencies in the audible range. The electromagnet is energized by current having a frequency in the neighborhood of these resonant frequencies. There may be a third vibrating plate coupled with the second vibrating plate by a second air spring. In this event the vibrating system has three resonant frequencies in the audible range.

Abstract: An electroacoustic transducer particularly for small small-sized portable equipment such as a wristwatch comprises a first vibrating plate which is vibrated by means of an electromagnet and a second vibrating plate which is coupled with the first vibrating plate by an airtight space which acts as an air spring. The first and second vibrating plates have different natural resonant frequencies so that the vibration system comprising the two vibrating plates and the air spring coupling them with one another forms a vibration system having two resonant frequencies. A resonant air chamber superposed on the second vibrating plate has a sound radiating port and has a resonant frequency between the two resonant frequencies of the vibration system comprising the first and second vibrating plates and coupling air spring. The electroacoustic transducer thus responds to a considerable range of frequencies.

Abstract: A process for producing a flame resistant polyurethane foam by reacting a reaction mixture comprising a polyetherpolyol or a polyesterpolyol having an active hydrogen atom, a polyisocyanate, water and/or a volatile foaming agent, and a catalyst, in which a specific amine compound shown by the general formula as defined hereinafter in the specification is added to the reaction system, and also the flame resistant polyurethane foam produced by the process.

Abstract: An electro-acoustic transducer of electromagnetic type is composed of an exciting part having a magnetic core wound with an exciting coil, a vibrating plate provided opposite to the magnetic core at an interval and a ferromagnetic thin plate mounted to the vibrating plate. The thin plate is provided on the surface of the vibrating plate on the side of the magnetic core, so that the thin plate is not exposed to the open air. Furthermore, the thin plate is connected to the vibrating plate at plural points more than three or at a part with some area. Such connection restrains undesirable vibration of the thin plate.

Abstract: A process for producing a flame resistant rigid polyurethane foam by reacting a reaction mixture comprising a polyetherpolyol and/or a polyesterpolyol having an active hydrogen atom, a polyisocyanate, water and/or a volatile foaming agent and an emulsifying agent, in which a specific amine compound shown by the general formula as defined hereinafter in the specification is added to the reaction system, the weight ratio of amine compound to polyetherpolyol and/or polyesterpolyol being from 70:30 to 30:70, and also the flame resistant rigid polyurethane foam produced by the process.

Abstract: A process for producing a flame resistant rigid polyurethane foam by reacting a reaction mixture comprising a polyetherpolyol and/or a polyesterpolyol having an active hydrogen atom, a polyisocyanate, water and/or a volatile foaming agent and an emulsifying agent, in which a specific amine compound shown by the general formula as defined hereinafter in the specification is added to the reaction system, the weight ratio of amine compound to polyetherpolyol and/or polyesterpolyol being from 70:30 to 30:70, and also the flame resistant rigid polyurethane foam produced by the process.