Abstract: When an abnormality occurs in a first voltage detector (4a), a control circuit (7) in an uninterruptible power supply device controls an inverter (3) in synchronization with an output signal (VI2D) from a second voltage detector (4b) to match a phase of a two-phase AC voltage (VO1, VO2) output from the inverter (3) with a phase of a two-phase AC voltage (VI1, VI2) supplied from a commercial AC power supply (51), and then turns on a semiconductor switch pair (S9, S10) and a bypass switch pair (S7, S8). Accordingly, even when an abnormality occurs in the first voltage detector (4a), the two-phase AC voltage can be supplied to a load (53) without instantaneous interruption.

Abstract: An uninterruptible power supply device (U1) includes a converter (40), an inverter (41), a bidirectional chopper (24), and a controller (53). The bidirectional chopper (24) includes first to fourth transistors (Q11-Q14), first to fourth diodes (D11-D14), and first and second, coils (51, 52). In a charging mode, the controller (53) causes the first and fourth transistors (Q11, Q14) to be complementarily turned on and controls the ON period of each of the first and fourth transistors (Q11, Q14) so as to cause respective detected values of first current and second current (11, 12) flowing through the first coil and the second coil (51, 52) to be equal to each other.

Abstract: A bidirectional insulated DC/DC converter narrows a pulse width of an AC fundamental wave voltage corresponding to a higher DC voltage of two DC voltages, to cause effective values of the AC fundamental wave voltages to coincide with each other, and then, sets a phase difference between the AC fundamental wave voltages in accordance with a value and a direction of a current that is desired to flow. Accordingly, even when the difference between the two DC voltages greatly varies, DC power can be stably transmitted and received.

Abstract: An uninterruptible power supply device (U1) includes a converter (40), an inverter (41), a bidirectional chopper (24), and a controller (53). The bidirectional chopper (24) includes first to fourth transistors (Q11-Q14), first to fourth diodes (D11-D14), and first and second, coils (51, 52). In a charging mode, the controller (53) causes the first and fourth transistors (Q11, Q14) to be complementarily turned on and controls the ON period of each of the first and fourth transistors (Q11, Q14) so as to cause respective detected values of first current and second current (11, 12) flowing through the first coil and the second coil (51, 52) to be equal to each other.

Abstract: An uninterruptible power supply device (60) does not have a wire connecting a bidirectional chopper (24) to a neutral point (NP). The bidirectional chopper (24) includes first and second capacitors (C11, C12), first to fourth transistors (Q11-Q14), and a normal mode reactor (50). In a discharging mode, a controller (63) causes the second and third transistors (Q12, Q13) to be complementarily turned on and controls the ON period of each of the second and third transistors (Q12, Q13) so that terminal-to-terminal voltages (V11, V12) of the first and second capacitors (C11, C12) are equal to each other.

Abstract: A pivot shaft (10) which is a first shaft member coupled to a supporting member, an inner cylinder (12) which is a second shaft member coupled to a supported member, and an outer cylinder (14) which is a third shaft member are disposed to be approximately coaxial with each other and disposed radially in multiple layers. The pivot shaft (10) and the inner cylinder (12) are coupled to each other through a first rubber-like elastic member (11), and the inner cylinder (12) and the outer cylinder (14) are coupled to each other through a second rubber-like elastic member (13). The total reaction force is increased by restricting the rotation of the outer cylinder (14) by means of an operating pin (19) which is a reaction force adjusting part and thereby adding a reaction force resulting from the second rubber-like elastic member (13) to a base reaction force resulting from the first rubber-like elastic member (11).

Abstract: Furniture and a chair include a shielding piece (7b5) which is provided in an operation plate (7b2) or a flange (7a5) and closes a gap generated by the operation plate (7b2) and the flange (7a5) when the operation plate (7b2) has an operation posture. In addition, a chair includes a load support member for a chair, the load support member for a chair includes a frame member which includes a pair of rod members (19) and an extension material (22) which is formed in a bag shape and covers the frame member, a support portion (26) is provided on each of inner surfaces facing each other in the pair of rod members (19), and an interior material (21) having a repulsive force with respect to a load in a surface perpendicular direction is bridged between the pair of rod members (19) by being supported by the support portion (26).

Abstract: Provided is an uninterruptible power supply apparatus that can properly adjust the capacity of cooling a heat radiation source. A housing for housing an uninterruptible power module is provided with a cooling fan for cooling the internal space of the housing. The housing is further formed with an opening. The opening formed in one housing and the opening formed in an adjacent housing for housing another uninterruptible power module are configured to face each other. Furthermore, each uninterruptible power module includes a fan control circuit for controlling the cooling fan. The fan control circuit controls the actuation and suspension of the cooling fan on the basis of a total load of the plurality of uninterruptible power modules.

Abstract: An armrest device for a chair includes a lower support rod that rises at a side of a chair seat and has a tubular upper end portion; and an upper support cylinder that has an armrest provided in an upper end thereof, is externally fitted to the lower support rod so as to be slidable in an up-down direction, and has a plurality of engaging portions therein. The armrest is made height-adjustable with respect to the lower support rod by disposing the locking member and a biasing member at an upper end portion of the lower support rod and providing the rotating rod inside the lower support rod.

Abstract: A chair includes: a leg body; a backrest supporting body supported by the leg body; a backrest rear supporting member supported by the backrest supporting body; and a backrest that is supported by the backrest rear supporting member and supports the back of a user. The backrest has: a flexible upholstering material configured to receive the back of the user and is displaceable depending on the back; and a pair of vertical frame sections that are mounted on the upholstering material, have lower ends connected to the back rest rear section support section, and are separated in a width direction in which twisting deformation is allowed depending on a force applied from the upholstering material.

Abstract: A bidirectional insulated DC/DC converter narrows a pulse width of an AC fundamental wave voltage corresponding to a higher DC voltage of two DC voltages, to cause effective values of the AC fundamental wave voltages to coincide with each other, and then, sets a phase difference between the AC fundamental wave voltages in accordance with a value and a direction of a current that is desired to flow. Accordingly, even when the difference between the two DC voltages greatly varies, DC power can be stably transmitted and received.

Abstract: Provided is an uninterruptible power supply apparatus that can properly adjust the capacity of cooling a heat radiation source. A housing for housing an uninterruptible power module is provided with a cooling fan for cooling the internal space of the housing. The housing is further formed with an opening. The opening formed in one housing and the opening formed in an adjacent housing for housing another uninterruptible power module are configured to face each other. Furthermore, each uninterruptible power module includes a fan control circuit for controlling the cooling fan. The fan control circuit controls the actuation and suspension of the cooling fan on the basis of a total load of the plurality of uninterruptible power modules.

Abstract: A load-supporting body includes a base plate constituting a framework; a cushion material arranged on a front surface side of the base plate; an upholstery material stretched to cover an outside surface of the cushion material and an outer peripheral edge of the base plate; and a tightening cord inserted through a peripheral edge of the upholstery material and tightened to allow end parts to be tied together on a rear surface side of the base plate in a state in which the upholstery material has covered the outside surface of the cushion material and the outer peripheral edge of the base plate. The base plate is provided with a first side wall and a first protruding wall that restricts displacement of the tightening cord in a base-plate center direction, and a second side wall and a second protruding wall that restrict displacement of the tightening cord in a base plate outward direction.

Abstract: A chair is provided in which a seat-receiving member is provided with outward flanges for regulating upward/downward displacement to support left and right lateral edges of a seat plate. Engaging grooves supported by the outward flanges are provided at the respective left and right lateral edges of the seat plate. Warpage allowable parts in which warpage deformation of the lateral edges is allowed without the upward displacement being regulated by the seat receiving member are provided in regions of the left and right lateral edges of the seat plate, in which the regions are located at a rear side from engagement parts between the engaging grooves and the outward flanges. With this constitution, it is possible to prevent the seat plate from being detached from the seat-receiving member while ensuring that, when an user is seated, the sides of the buttocks of the user are reliably held, and thus improve the seating stability of a seat body.

Abstract: A chair includes: a leg body; a backrest supporting body supported by the leg body; a backrest rear supporting member supported by the backrest supporting body; and a backrest that is supported by the backrest rear supporting member and supports the back of a user. The backrest has: a flexible upholstering material configured to receive the back of the user and is displaceable depending on the back; and a pair of vertical frame sections that are mounted on the upholstering material, have lower ends connected to the back rest rear section support section, and are separated in a width direction in which twisting deformation is allowed depending on a force applied from the upholstering material.

Abstract: A chair includes: a leg body; a backrest supporting body supported by the leg body; and a backrest supporting body supported by the backrest supporting body and configured to support the back of a user. The backrest supporting body has: a backrest which has a flexible upholstering material member that receives the back of the user and enables displacement depending on the back and a pair of vertical frame sections on which the upholstering material member is mounted and which are separated in a width direction in which the vertical frame sections are elastically deformable by a force applied from the upholstering material member; and a backrest rear section supporting member configured to connect the vertical frame sections—in an upward/downward direction.

Abstract: A power supply system includes a plurality of uninterruptible power supplies provided for a load in parallel. The uninterruptible power supplies each include a power supply unit configured to supply the load with power and being larger in capacitance than the load, and a switch provided between the power supply unit and the load. The power supply system further includes a control unit selecting a first uninterruptible power supply of the plurality of uninterruptible power supplies, and setting the switch of the first uninterruptible power supply to the on state.

Abstract: An armrest device for a chair includes a lower support rod that rises at a side of a chair seat and has a tubular upper end portion; and an upper support cylinder that has an armrest provided in an upper end thereof, is externally fitted to the lower support rod so as to be slidable in an up-down direction, and has a plurality of engaging portions therein. The armrest is made height-adjustable with respect to the lower support rod by disposing the locking member and a biasing member at an upper end portion of the lower support rod and providing the rotating rod inside the lower support rod.

Abstract: A stretching structure in which upholstery material can be installed in a frame body, enough deflection allowance of the upholstery material can be ensured. Upholstery material (14) is installed on the surface of a frame body (13) in a closed-loop shape, and is used as the seat or the backrest of a chair. A cross-sectional shape perpendicular to the longitudinal direction of each of the sections of the frame body (13) is provided with an upholstery material receiving section (21) having an engaging groove (20) which is open to the back surface side, and a U-shape section (23) having a recessed groove (22) which is open to the surface side inward more than the engaging groove (20). The upholstery material (14) is wound from the surface of the frame body (13) to the back surface side along the outer peripheral surface, and the edge section is fitted in the engaging groove (20) and tied up, thereby installing the upholstery material (14) in such a manner as to cover the surface of the U-shape section (23).

Abstract: A chair with armrest includes a support base supported by a leg, a seat that is pivotally fixed to the support base using an axle extending in a left and right direction, the rear part of the seat being rotatable upward and downward, an impelling unit that is provided at the support base and impels the seat at the rear of the axle upward, and an armrest provided to the support base. When the rear part of the seat rotates upward or downward, the height of the armrest does not change, and therefore arms or the like are not squeezed between the top plate of a desk and the armrest.