Abstract: At least two vibration proof elements are interposed between a tool body and the handle thereof. Each of the elements has a first supporting member connected to the handle, and two rubber blocks interposed between the first and second supporting members so that the element functions as a shock absorber. The first supporting member is partially received in the second supporting member in such a manner that the first supporting member is reciprocally movable with respect to the second supporting member when a force is applied to the element in a longitudinal direction of the tool body. Each of the first and second supporting members has a U-shaped portion so that the inner surface of the second supporting member abuts the outer surface of the first supporting member thus preventing the handle from excessively rotating about an axis perpendicular to the longitudinal axis, and passing through the elements.

Abstract: A battery casing for receiving one or more batteries, such as dry cells, to supply a battery-powered electrical device comprises first and second terminals for deriving electrical power from the battery. At least one of the first and second terminals is entirely received in the bore of the casing and is arranged to be in contact with an external conductor which will be inserted through an opening made in the top portion of the casing. The battery casing comprises a slidable member which opens and closes the opening at the top portion. The slidable member can be manipulated to assume its closed position so as to isolate at least one of the first and second terminals from the outside of the casing, preventing the terminals from making a short circuit. One of the first and second terminals, which can be isolated by the slidable member, is fixedly supported by an insulating member and is substantially U-shaped, while the other terminal may be L-shaped and a portion thereof is exposed outside.

Abstract: In a high speed impact printer of the type arranged to impact a plurality of print hammers against given types carried by a type carrier by energizing corresponding solenoids, the energization of given solenoid or solenoids is started from a given point of time. The given solenoid(s) is/are continuously energized for a predetermined interval which is accurately determined by digital circuitry having a counter. A memory for storing data each indicative of a place in a print line in each address thereof, is provided, where a given address of the memory is periodically read and written at a given interval in response to the output signal of the counter which periodically counts the number of clock pulses. The data stored in the memory is decoded to terminate the energization of the given solenoid(s).

Abstract: A power tool comprising a brush holder assembly formed of a plastic material, a printed circuit board and a positioning member for positioning the terminals of a switch and a power cable in contact with the printed circuit board. The brush holder assembly includes a pair of spaced apart arm portions each carrying a brush for making contact with the commutator and a web portion. In each of the arm portions of the assembly is embedded a pair of conductors each having a terminal at one end thereof for making electrical contact with a corresponding terminal of the stator, the other end of each conductor making contact with the printed circuit board. The printed circuit board is provided with a conductive pattern which permits the terminals of the switch and power cable to be mutually connected and further permits them to be connected to the conductors of the brush holder assembly to complete a series circuit.

Abstract: The print timing, with which a print hammer impacts a desired type moving on a type carrier, is advanced and then retarded or vice versa during test printing to find an ideal print timing. The amount of advancing and retarding respectively correspond to the negative and positive tolerance limits of the variation in flight time of the print hammer. During test printing the print timing is further advanced and/or retarded so that printed samples are perfect, and then the timing, which has been further advanced or retarded, is used to determine the ideal print timing. Circuit arrangements for performing the method are also disclosed as embodiments of the invention.

Abstract: A microcomputer which controls a device or apparatus in accordance with a control program prestored in a Read Only Memory included in the microcomputer, further comprises a Random Access Memory for storing parity bits of the control program. The data indicative of the control program prestored in the Read Only Memory are read out in sequence and are fed to a central processing unit of the microcomputer so that parity bits of the prestored data are produced and then stored in the Random Access Memory. The parity bits stored in the Random Access Memory are used to check whether the prestored data are correct or not.

Abstract: A percussion drill comprises an open-ended, hollow cylinder having an air exhaust hole on the side wall thereof, a piston mounted in the rear end portion of the cylinder, and a slide shaft mounted in the front end portion of the cylinder. A drill bit is releasably attached to the forward end of the slide shaft for working with a material. Between the piston and the slide shaft is mounted a striker which forms a forward variable volume air chamber and a rearward variable volume air chamber. The piston is driven by a motor-crankshaft arrangement to reciprocate axially in the cylinder to cause a positive high pressure to develop in the rearward chamber, which pressure provides an impact on the striker whose mechanical energy is transferred to the slide shaft. A return movement of the piston develops a negative pressure in the rearward chamber to pull back the striker to the impact position.

Abstract: An upper cover for a line printer in which an upper cover hood can be easily opened forwardly to permit full maintenance of the printing mechanism. The upper cover hood is pivotally coupled through a rear hinge holder to a forwardly-extending support member via a balance holder. A balancing mechanism is pivotally coupled at one end to the balance holder. At the front end of the support member a hook member is hingedly attached, the other end of which is adapted to be swung into position and coupled to a pin which is rigidly coupled to a side wall of the upper cover hood. A cushioning packing is disposed along the front edge of the upper cover hood.

Abstract: In a printing apparatus having a platen, a plurality of print hammers arranged in a horizontal row and a horizontally movable type carrier on which print carriers are arranged, a restraining member limits upward movement of a horizontally movable ink ribbon and thereby eliminates character omission. Between the print hammers and the type carriers are disposed the horizontally movable ink ribbon and a vertically movable print sheet on which a character impression is made upon impact of a selectively energized hammer. The print sheet is folded along transverse cut lines to define forms which are stacked together below the apparatus. When the print sheet is pulled upwardly, the folded portion tends to drag the ink ribbon upwardly displacing the ribbon from its print position. The restraining member is mounted above the ink ribbon to limit this upward movement of the ribbon.

Abstract: A sleeve member of elastomeric material is mounted on one of the driving and driven pulleys between which the type-carrier is passed. The sleeve member is wetted with a lubricant liquid so that a friction occurring between the type-carrier and the platen is minimized.

Abstract: A failure detection circuit for stepping motors having a rotor and a motor control circuit including first and second transistors respectively connected in series with first and second stator coils. The rotor is set in motion in response to energization of the second stator coil when the second transistor is activated and brought to a halt in response to energization of the first stator coil when the first transistor is activated. During the interval when the first transistor is activated, the potential at a circuit junction between the respective transistor and the associated coil is detected and compared with the logic level of the input to the associated transistor to check for a set of operational states of the circuit elements to give a warning indication if the compared levels have a predetermined relationship to each other.

Abstract: In a mowing machine having an engine for driving a rotary blade via a centrifugal clutch, a shaft and a reduction gear assembly, the outer diameter of the shaft is selected such that the torsional natural vibration frequency of the rotational system extending from the engine to the rotary blade is less than one third of a rotational frequency above which the centrifugal clutch starts transmitting the engine output torque to the shaft. As a result, the torsional natural vibration frequency of the rotational system does not equal the rotational frequency or the half or one third of the rotational frequency of the engine so that undesirable resonance phenomenon will not occur.

Abstract: A magnetic interference prevention system in a printer comprising a plurality of print hammers whose hammering surfaces are disposed in a straight line and a plurality of printing magnets arranged adjacent one another to drive each of the print hammers respectively. In this system when a signal to drive a first printing magnet for a column is provided the driving of at least one of two printing magnets adjacent to the first printing magnet is inhibited for a predetermined period of time. This will prevent three adjacent printing magnets from being driven substantially at the same time.

Abstract: A printing device having a plurality of print hammers having striking surfaces arranged along a print line and print magnets provided adjacent to one another for driving the printing hammers. A magnetic interference preventing device comprises a memory for storing for each column the excitation lapse time information of the print magnets. A reader which, when exciting each print magnet is started, reads the excitation lapse time information of both print magnets adjacent to each print magnet out of the memory. The reader outputs a signal only when the excitation lapse times of both print magnets are in a predetermined range of time. An inhibitor is used for inhibiting the excitation of each print magnet when the excitation lapse times of both print magnets are within the predetermined range of time.

Abstract: An improved printing magnet drive device for use in a printing apparatus, such as line printer, is disclosed. The improvement comprises a constant voltage control means in which an output terminal voltage of a transistor is compared with a reference voltage and the comparison result is fed back to the transistor so as to control the output terminal voltage of the transistor to a predetermined value, whereby the voltage applied to the printing magnets is substantially maintained unchanged.

Abstract: An impact printing apparatus of the back-impact or front impact type having a frame construction composed of first and second frame structures positioned in a fore-and-aft direction of the apparatus and having impact hammers mounted on one of the frame structures, and a tiltable member positioned on one side of the frame structures, wherein the first frame structure is pivotally connected to the tiltable member about a vertical axis along one side end of the first frame structure and the tiltable member in turn is pivotally supported on the second frame structure about an axis in a lateral direction of the printing apparatus.

Abstract: A high density liquid is used to simultaneously transfer a liquid sample and a liquid reagent from antechambers formed in a centrifuge rotor to a transmissive measurement chamber formed in a radially outer region of the same rotor. The antechambers for the sample and the reagent and a reservoir chamber for the high density liquid are all elongated radially of the rotor and in fluidic connection through the radially outermost ends of the respective chambers. First the high density liquid is introduced into the antechambers so as to occupy a radially outer portion of each chamber, and then the sample and the reagent are introduced into the respective antechambers through their radially innermost ends. Thereafter the sample and the reagent are forced to flow out of the respective antechambers to enter the measurement chamber by additionally introducing the high density liquid into the reservoir chamber while the rotor is rotating.

Abstract: In a paper feed control system employing a pulse motor steppingly rotatable in response to driving pulses, paper feeding is controlled by a prepunched format tape wherein line pulses generated every one line feeding of the paper are in synchronism with perforations detected from the format tape. Briefly, the format tape is moved by the pulse motor, and when a first perforation is detected therefrom a predetermined number of the driving pulses is applied to the pulse motor, whereby the format tape is moved to an approximate midpoint of the perforation. A first line pulse is generated in response to the predetermined number of the driving pulses so that the line pulse is generated in approximate midpoint of the first perforation. Accordingly, the succeeding line pulses are generated in the approximate midpoints of the succeeding perforations.

Abstract: A printing apparatus comprising a stationary frame structure having accommodated therewithin a plurality of printing hammers arranged in a row, a tiltable support structure positioned in front of the frame structure and rotatable about an axis fixed on the frame structure, a type carrier movable on the support structure partially along a straight travelling path extending in parallel with the row of the printing hammers and forming an elongated clearance between the travelling path and the row of the printing hammers, position retaining means for holding the support structure in an inoperative position having the travelling path of the type carrier spaced wider apart from the row of the printing hammers, clearance adjusting means for minutely adjusting the above mentioned clearance depending upon the thickness of the printing sheet or sheets to be printed at a time, and cam means providing a mechanical and functional intervention between the position retaining and clearance adjusting means.

Abstract: A printing apparatus comprising a type carrier to travel along a print line on a printing paper, a plurality of printing hammers to be selectively driven to strike the printing paper against an inking ribbon and the inking ribbon against a platen in front of the inking ribbon, and a support member supporting the type carrier, inking ribbon and platen thereon, wherein the support member is movable between a position holding the type carrier, inking ribbon and platen in positions capable of performing printing operation but intercepting the line of sight between the print line and the operator's eyes and a position holding the type carrier, inking ribbon and platen in inoperative positions but providing an unobstructed line of sight from the operator's eyes toward the print line for enabling the operator to clearly view the printed information along the print line.