Abstract: A showcase having a fin-and-tube type cooler includes planar fins and a refrigerant pipe penetrating through the planar fins. The planar fins include long fins arranged in parallel to an air flow direction through the cooler, and short fins shorter in length than the long fins and arranged between adjacent long fins at a downstream side of the cooler. The refrigerant pipe includes first U-shaped hair pins having two straight pipe portions, and second U-shaped hair pins having two straight pipe portions. The pitch between the two straight pipe portions of each second U-shaped hair pin is set to double the pitch between the two straight pipe portions of each first U-shaped hair pin. The first and second U-shaped hair pins penetrate through the hole portions formed in the plural planar fins so as to be arranged in a predetermined style.

Abstract: A vibration isolator includes an elastic body. The elastic body has a pair of main spring portions extending on both sides in a first axis-perpendicular direction from an outer peripheral surface of an inner cylinder body and coupled to an inner peripheral surface of an outer cylinder body, and an axis-perpendicular stopper portion protruding inward in a second axis-perpendicular direction perpendicular to the first axis-perpendicular direction from the inner peripheral surface of the outer cylinder body and restricting relative movement between the inner and outer cylinder bodies in the second axis-perpendicular direction. The vibration isolator further includes a first coupling elastic body provided between the axial stopper elastic body and one of the main spring portions to couple them together, and a second coupling elastic body provided between the axial stopper elastic body and the axis-perpendicular stopper portion to couple them together.

Abstract: Disclosed is a refrigeration apparatus capable of minimizing the pressure loss of a refrigerant circulated through an internal heat exchanger and capable of improving a cooling capability. A refrigeration apparatus in which a compressor, a radiator, an electronic expansion valve and an evaporator are successively annularly connected to one another to constitute a refrigerant circuit includes a refrigerator unit provided with the compressor and the radiator, and a cooling unit provided with the electronic expansion valve and the evaporator, the refrigerator unit is connected to one or a plurality of cooling units via a communication pipe to constitute the refrigerant cycle, an internal heat exchanger which performs heat exchange between a refrigerant discharged from the radiator and a refrigerant discharged from the evaporator is constituted of a double tube, and the internal heat exchanger is provided in the cooling unit.

Abstract: A bell-mouth structure of an air blower provided around a blade wheel of an axial-flow air blower for guiding air from an air suction side of the blade wheel to an air blow-out side including an air blow-out wall portion that intercommunicates with an air blow-out opening and extends substantially along an axial direction of the blade wheel, and a slope wall portion that intercommunicates with the air blow-out wall portion and slopes to an air suction opening so as to expand in diameter. When the overall height of the bell-mouth is represented by H, the height of the slope wall portion is represented by h and a slope angle of the slope wall portion is represented by ?, the bell mouth structure is configured so as to satisfy 0.33?h/H?0.42 and 60°???70°.

Abstract: Disclosed is a refrigeration apparatus capable of minimizing the pressure loss of a refrigerant circulated through an internal heat exchanger and capable of improving a cooling capability. A refrigeration apparatus in which a compressor, a radiator, an electronic expansion valve and an evaporator are successively annularly connected to one another to constitute a refrigerant circuit includes a refrigerator unit provided with the compressor and the radiator, and a cooling unit provided with the electronic expansion valve and the evaporator, the refrigerator unit is connected to one or a plurality of cooling units via a communication pipe to constitute the refrigerant cycle, an internal heat exchanger which performs heat exchange between a refrigerant discharged from the radiator and a refrigerant discharged from the evaporator is constituted of a double tube, and the internal heat exchanger is provided in the cooling unit.

Abstract: A showcase having a fin-and-tube type cooler which comprises plural planar fins and a refrigerant pipe penetrating through the plural planar fins and cools air to be fed toward display racks, wherein the plural planar fins comprise long fins arranged in parallel to an air flow direction along which air flows through the cooler, and short fins that are shorter in length in the air flowing direction than the long fins and arranged between respective adjacent long fins at the downstream side of the cooler with respect to the air flowing direction.

Abstract: An overtone crystal oscillator includes a crystal vibrator, a CMOS circuit connected in parallel to the crystal vibrator, and two load capacitors connected to the input and output of the CMOS circuit, respectively. The capacitors have respective capacitances C.sub.g and C.sub.d determined to satisfy at least one of following two conditions wherein the first condition is that an oscillation starting resistance R.sub.KN of a desired N-th overtone is sufficiently larger than an effective resistance R.sub.QN of the crystal vibrator of the N-th overtone, the oscillation starting resistance being expressed as:R.sub.KN =K/(.omega..sup.2 .multidot.C.sub.g .multidot.C.sub.d)(.omega.: oscillating frequency, K: constant determined by mutual conductance of the CMOS circuit) and the second condition is that an effective resistance R.sub.Qn of the crystal vibrator of another n-th overtone except the desired N-th overtone satisfies the following relationR.sub.Qn >N.sup.2 .multidot.R.sub.KN /n.sup.2.

Abstract: A driving electrode on a surface of the piezoelectric vibrator in accordance with the present invention has a blank which is narrow at the center portion and wide at the right and left portions on the Z axis. And the driving electrode is the shape easy to operate in the fundamental main vibration, and hard to operate in the spurious vibration. Thus the piezoelectric vibrator operates efficiently in the fundamental main vibration.

Abstract: A thickness-shear mode piezo-electric vibrator comprises a piezo-electric crystal operable in the thickness-shear mode, driving electrodes formed on opposed surfaces of the crystal, and an addition mass formed on at least one of the driving electrodes and positioned on the nodal line of a 3-fold harmonic vibration so that the frequency f.sub.o of the fundamental main vibration and the frequency f.sub.3s of the 3-fold harmonic vibration always satisfy the following relation within the practical application ranges of temperature and load capacitance; ##EQU1## thereby effectively eliminating or preventing the "abnormal frequency phenomenon" which would otherwise occur due to the 3-fold harmonic vibrations.

Abstract: A quartz oscillator comprises a quartz blank having electrode films deposited on opposite parallel faces thereof. Holding wires which are parallel to the quartz blank extend along and spaced slightly from the opposite faces of the blank and are locally soldered to the quartz blank. The holding wires extend beyond the edge of the quartz blank and are secured to a holding substrate provided with electrical connections. The quartz oscillator is prepared by positioning a quartz blank and a holding substrate in a supporting frame, opposite faces of the quartz blank and holding substrate being provided at selected positions with solder parts. The holding wires are then positioned along opposite faces of the quartz blank and holding substrate and the solder parts are temporarily fused by radiant heat to bond the holding wires to the quartz blank and the holding substrate.

Abstract: A method of adjusting the frequency and temperature coefficient of a GT cut quartz oscillator comprises starting with a blank of approximately the frequency desired. An electrode film is deposited on the front and rear faces of the blank. The side ratio between a longer side and a shorter side is adjusted to obtain a zero temperature coefficient. Thereafter portions of the electrode film along the longer sides of the oscillator are removed to reduce the area of the electrode film so as to obtain the desired frequency without changing the side ratio and thus without disturbing the zero temperature coefficient.