Abstract: According to a method of adjusting a head gap, a wire dot head is set to a predetermined position of a reference head gap; a printing pattern for detecting printing time is printed by a plurality of pins; reference printing times of respective pins are detected. Next, a test printing is performed with test printing dots previously selected from printing data, and printing time of the test printing is detected. Then, the thickness of the printing media is calculated based on the reference printing time and the printing time of the test printing. At that time, a rule of thumb in which the difference of the printing time corresponds to the difference of the head gap, is used. Then, a shift amount of the wire dot head is calculated for setting the head gap to an optimum value according to the thickness of the printing media, and gap shifting mechanism shifts the wire dot head by the shift amount. This leads to highly accurate detection of the head gap and improves printing quality thereof.

Abstract: The present invention relates to an automotive vehicle engine having controls for switching between a whole cylinder working mode and a partial cylinder non-working mode by making a valve motion arrangement operated in the intake and exhaust process. The automotive vehicle engine comprises-a revolution sensor, a boost pressure sensor, an ignition driving apparatus and a controlling apparatus for controlling the cylinder suspending mechanism and the ignition driving apparatus. The partial cylinder non-working mode or the all cylinder working mode is determined on the basis of the revolution speed "Ne" and the boost pressure data "Pb".

Abstract: An impact printer having a print head, the print head having a movable armature, a printing wire fixed to the armature, and sensor for detecting movement of the armature. The position of the armature is monitored based on an output of the sensor. A home sensor detects whether the print head is at a home position. A paper end sensor detect whether a printing medium is between the platen and the print head. A gap motor means adjusts a gap between the printing wire and the platen. A gap controller is responsive to detection signals output by said home sensor and said paper end sensor, for controlling the print head to swing the armature so as to cause the tip of said printing wire to strike the platen, determining a time of impact of the tip with the platen based on the monitored position of the armature, performing a comparison of the time of impact with a predetermined impact time, and outputting a drive signal to the gap motor for adjusting the gap according to a result of the comparison.

Abstract: A controller for a dot impact printer has capacitance sensors for sensing the motion of the dot wires in the print head, and a non-volatile, rewritable memory for storing self-adjustment data relating to dot-wire characteristics. A processor controls the driving of the dot wires according to the self-adjustment data stored in the memory. At certain times, the processor causes the dot wires to be driven in a test sequence and updates the self-adjustment data in the memory according to the resulting sensor output. Print quality is thereby maintained for the full guaranteed life of the print head.

Abstract: A print head has a solenoid driving means which employs a filler mixed with a lubricating oil to fix an exciting coil to the core. The filler prevents the layer winding from being shorted due to corrosion of the exciting coil and prevents mechanical abrasion of the armature by supplying lubricating oil during extended operation.

Abstract: A spring charge type wire dot printing head includes front cores 35 and rear cores 36 that are disposed in circles. The front and rear cores are used in pairs, and either one of these paired cores is wound with a coil 39 or 40. Since the inductance of the coils 39 and 40 can be increased, low electric current and low electric power consumption can be realized.

Abstract: A permanent magnet suitable for use in a wire print head is formed of plural split segments. Each split segment is formed by compressing metal powder in a punching direction in the presence of a magnetic field that is perpendicular to the punching direction. The split segments are combined together into an annular configuration. The permanent magnet so formed is attached to a base, followed by the assembly of a base plate and cores to form a magnet assembly. The base plate and the cores are then surface-finished so as to be flush relative to each other.

Abstract: A spring-charged wire dot print head having printing wires is provided with back poles paired up respectively with the cores of electromagnets for cancelling the magnetic flux produced by a permanent magnet, to eliminate the adverse effect of magnetic interference liable to occur in driving the adjacent printing wires. The adjacent pairs of cores and back poles are opposite to each other with respect to the polarity of the magnetic path of the magnetic flux produced by the permanent magnet.

Abstract: A wire-dot print head has an armature having a tip to which a print wire is secured, a core provided in confrontation with the armature, a plate spring which is supported in a cantilever fashion and to which the armature is fixed, a permanent magnet assembly generating a magnetic flux to cause the armature to be attracted toward the core overcoming the resilient force of the plate spring, and a coil wound on the core to generate a magnetic flux upon energization to cancel the magnetic flux from the permanent magnet assembly, thereby to release the armature. The permanent magnet assembly includes a first permanent magnet of the samarium-cobalt type, and a second permanent magnet of the neodyminum-iron-boron type or the lanthanoid-iron-boron type.

Abstract: In a wire dot print head having print wires extending through an opening of a guide nose, the guide nose comprises two halves. The print head may further comprise a wire guide which is fitted in the guide nose and through which the print wires extend, and the wire guide may be clamped by the two halves. In another embodiment, the half members have abutting surfaces provided with semi-circular grooves, which when the guide nose halves are assembled, form guide holes in which the print wires are slidably supported. The use of the two halves facilitates assembly of the print head and reduces noise.

Abstract: In a spring-charge wire-dot print head, a support part of a plate spring is clamped, at its outer periphery, between a protruding member disposed on the front surface of the outer periphery of a spacer and a protruding member disposed on the rear surface of the outer periphery of a yoke, and the support part of the plate spring is additionally supported, at the rear surface of its inner periphery, by a protruding member disposed on the front surface of the inner periphery of the spacer.

Abstract: A dot print head includes a spring plate having a plurality of integral tongues arranged successively along one longitudinal side edge thereof, a plurality of armatures each fixedly attached at a part at least excluding the rear end thereof to the upper surface of a respective tongue of the spring plate with the rear end of each armature located on the side of the fixed longitudinal side portion of the spring plate with respect to the fixed point of primary vibration thereof caused by the tongue of the spring plate, and a plurality of styluses each fixed to the free end of a respective armature. A yoke member is fixedly attached to the upper surface of the fixed longitudinal side portion of the spring plate and has a plurality of recesses for loosely receiving the armatures therein, to exert the effect of a magnetic field on the corresponding armatures. A restrictor is located on the respective path of the respective rear end of each armature to limit the movement of the respective rear end of the armature.

Abstract: A structure of internal combustion engine comprises a cylinder member composed of a cylinder which accomodates a piston connected with a crankshaft, a crankcase provided to accomodate said crankshaft, a rocker case provided to accomodate a valve actuating mechanism, an oil return passage constituting means for leading oil in said rocker case into said crankcase, and a restraining means for restraining an air flow within said crankcase from entering into said oil return passage constituting means. By the effect of the restraining means provided in relation to the oil return passage constituting means, the air flow generated by the rotation of the crankshaft does not work as a dynamic pressure of hingering the flowingdown of oil.