Abstract: In a magnetic tape recording and playback device, a resilient body is engaged with a head base. At the time of recording and playing back a tape, the head base is pressed and fixed when the resilient member is directly pushed by a drive plate, and at the time of withdrawing the head, the head base driven by the drive plate, through the resilient member, and the head base is pressed and fixed. In this way, a force given to the resilient body is reduced at the time of head base movement. It is possible to reduce the required head base drive force at the time of head base movement.

Abstract: Disclosed are a carbonate group-modified epoxy resin in which carbonate groups are introduced into an epoxy resin having secondary hydroxyl groups at terminals or lactone-modified epoxy resin having primary hydroxyl groups at terminals by the ring-opening reaction of a cyclic alkylene carbonate, a process for the preparation thereof, and a thermosetting resin composition containing the carbonate group-modified epoxy resin.

Abstract: For use as a monomer for producing hydroxyl group-containing vinyl polymers, there is provided a compound of the formula: ##STR1## wherein R.sup.1 is acryloyl, methacryloyl or 4-vinylbenzyl; R.sup.2 is an alkyl; and R.sup.3 is an alkyl, alkoxyalkyl, alkenyl, alkynyl, aralkyl or aryl.

Abstract: A hydroxy-terminated linear carbonate is produced by reacting a cyclic alkylene carbonate such as neopentyl glycol carbonate with a substance having at least one alcoholic hydroxyl group in the presence of a catalyst. Mono- or polyhydric alphatic alcohols, polycaprolactone polyols, hydroxyl group-containing acrylic monomers and polymers, and polyester polyols are modified by the reaction with the cyclic alkylene carbonate to have an enhanced reactivity and resistance to hydrolysis.

Abstract: Disclosed herein is a long wavelength multiple quantum well semiconductor laser which is capable of preventing the nonuniform injection of carriers into quantum wells, and the overflow of the electrons within the quantum wells, and which is also capable of suppressing the increase in the threshold caused by insufficient gain, and the increase in the threshold and the deterioration in the slope efficiency caused by internal absorption loss.

Abstract: A curable resin composition utilizing as the crosslinking mechanism thereof an acid catalyzed addition reaction of a cyclic alkylenecarbonate group with an alcoholic hydroxyl group is disclosed. The composition contains a compound or polymer having a plurality of 6-membered cyclic alkylenecarbonate groups and a polymer having a plurality of alcoholic hydroxyl groups. A polymer having pluralities of the cyclic alkylenecarbonate and hydroxyl groups in a single entity may also be used. The composition cures at room or elevated temperatures depending upon the acidity and amount of particular acid catalyst incorporated to the composition.

Abstract: A hydroxy-terminated linear carbonate is produced by reacting a cyclic alkylene carbonate such as neopentyl glycol carbonate with a substance having at least one alcoholic hydroxyl group in the presence of a catalyst. Mono- or polyhydric alphatic alcohols, polycaprolactone polyols, hydroxyl group-containing acrylic monomers and polymers, and polyester polyols are modified by the reaction with the cyclic alkylene carbonate to have an enhanced reactivity and resistance to hydrolysis.

Abstract: Provided is a convenient method for synthesizing quaternary ammonium salts which are useful as curing catalysts for one-part thermosetting resin compositions which maintain storage stability at room temperature. The ammonium salts are synthesized by direct reaction of a benzyl alcohol or a benzyl alkyl ether optionally having on the benzene ring and/or at .alpha.-position one or more substituent groups inert to the intended reaction, with a corresponding strong-acid salt of a tertiary amine.

Abstract: Provided is a convenient method for the synthesis of quaternary ammonium sulfonate compounds which are useful as curing catalysts for one-part thermosetting resin compositions which maintain storage stability at room temperature. The compounds are synthesized by subjecting in one step a benzyl alcohol optionally having on the benzene ring and/or the .alpha.-position one or more substituent groups to reaction with a corresponding tertiary amine and an organic sulfonic acid chloride.

Abstract: A magnetic tape apparatus for loading and unloading magnetic tape having first and second rotatable reel winders with first and second reel brake arms for providing a braking force to the reel winders. A locking device is provided for locking the first reel winder when unloading the magnetic tape upon release of the first reel winder by the first brake arm while allowing the second reel winder to freely rotate.

Abstract: A sealed electric switch comprises a molded switch housing and a separately formed cover which fits on the switch housing wiht an annular seal member interposed between mating peripheral surfaces of the switch housing and the cover. An annular seal member is injection-molded from an elastic material on the mating peripheral surface of the switch housing between separable molding dies with the switch housing held therebetween. The annular seal member is integrally formed with an additional segment which extends in a separating direction of the molding dies and joins at its end to the annular seal member so as to reinforce it against a separation force applied thereto at the time of separating the molding dies.

Abstract: A tape loading apparatus according to the present invention comprises a cam gear and a first and second arms that are pivotally mounted by a chassis. The second arm has a guiding pin, and engages the first arm through an urging spring mounted between the two arms. The first arm member is provided with a guiding pin at one end portion thereof which engages a cam groove of the cam gear and is guided along the cam groove from a first end to a second end of the groove when the cam is rotated. Before the guiding pin reaches the second end of the cam groove, the pinch roller abuts a capstan and is the pressed against the capstan by an urging force of the spring when the guiding pin reaches the second end of the case cam groove.

Abstract: A magnetic tape unit comprising a head component having a rotatable drum provided with a magnetic head, a guide plate having a tape guide mechanism for leading a magnetic tape into contact with the head component, a supporting base for supporting the head component with the rotation surface of the magnetic head inclined at predetermined angle against the guide plate, the thermal coefficient of expansion thereof being different from that of the guide plate, and mounting means for fitting the supporting base to the guide plate and for absorbing the difference in the degree of expansion and contraction therebetween appeared in a direction in parallel with the surface of the guide plate due to the difference of the thermal coefficient of expansion therebetween.

Abstract: Method for manufacturing an electric switching block of an electromagnetic relay wherein a rocking armature end or ends of an electromagnetic block drives respective movable contactor spring plates between opposing fixed contact terminals in respective switching sections of the switching block.

Abstract: An automatic power-driven screwdriver comprises a first cylindrical member having a hand grip portion, a guide portion, a tapered portion and a flanged portion between the tapered and hand grip portions. A second cylindrical member, which is a nose portion of the screwdriver, is mounted to telescope over the guide portion. A third cylindrical member encircles the guide portion and is slidably mounted at one end over the second cylindrical member. The third member is formed with a tapered contacting surface complementary to the surface of the tapered portion of the first member. An adjusting nut having an inwardly extending flange is mounted on the first member with the flange being in contact with the flanged portion and is threadably engaged with the third member so that the tapered contacting surfaces are brought into firm pressure contact which enables the first and second cylindrical members to be secured firmly together.

Abstract: A memory pack is provided having a random access memory connected between a positive power source terminal and a ground terminal, an addressing terminal coupled with the random access memory, and a data input/output terminal coupled with the random access memory. The memory pack further includes an LED energizing terminal, a light emission element which is connected between the LED energizing terminal and a positive power source terminal, the LED being lit by an energizing signal applied to the LED energizing terminal, a RAM energizing terminal and a photocoupler which is connected between the RAM energizing terminal and the random access memory and which responds to an energizing signal applied to the RAM energizing terminal to apply an output signal to the random access memory thereby to set the random access memory to be operative.

Abstract: An electronic cash register is provided which comprises a keyboard including a plurality of entry keys, function keys and department keys, a memory, a first interface circuit with which a cashier memory pack is mechanically, electrically and disconnectably coupled, a second interface circuit with which a terminal memory pack is mechanically, electrically and disconnectably coupled, and a central processing unit connected to the keyboard, the memory, and the first and second interface circuits in which the sales information generated upon depression of the entry keys, the function keys and department keys are loaded into the memory and at least the sales total for a customer in the sales information is loaded for each transaction into the cashier memory pack and the terminal memory pack.

Abstract: A data processing apparatus for an electronic cash register comprises a keyboard having a plurality of entry keys, a printer, a memory unit, an interface circuit with which a memory pack storing sales data is mechanically, electrically and removably coupled and a data processing unit connected with the keyboard, the printer, the memory unit and the interface circuit. Responding to operations of one of the keys for sales data selection, the data processing unit energizes the memory pack connected to the interface circuit to read out the sales data corresponding to the operated sales information key from the energized memory pack and write the read-out sales data into the memory unit and then issue a print signal to the printer for printing the sales data.

Abstract: A clock pulse control system for microcomputer systems includes a central processing unit, a plurality of first input/output units, a plurality of second input/output units and a clock pulse generator. The clock pulse generator generates a first clock pulse having a frequency to operate the central processing unit and the first input/output units and a second pulse having the same frequency or a different frequency to operate the second input/output units. Thus, the first input/output units are operated at the same frequency as the central processing unit. The second input/output units are operated by a second clock pulse having an optimum frequency when no information is transferred between the second input/output units and the central processing unit and by a second clock pulse having the operating frequency of the central processing unit when information is transferred between the second input/output units and the central processing unit.