초록 ▼

A combined stepladder and hand truck assembly is provided. The assembly comprises a first frame having two side rails, a second frame pivotally attached to the back side of the first frame and having two side rails, and a third frame pivotally attached to the front side of the first frame and having

A combined stepladder and hand truck assembly is provided. The assembly comprises a first frame having two side rails, a second frame pivotally attached to the back side of the first frame and having two side rails, and a third frame pivotally attached to the front side of the first frame and having two side rails. Steps and bars are provided so that they form a parallel link together with the side rails of the first frame. Two casters attached at the lower end of the first frame. A tool tray is provided at the lower end of the third frame. The tray is kept vertical to the frames when the assembly is used as a hand truck, and is kept horizontal when the assembly is used as a stepladder and the third frame is rotated upward to support the tool tray in a high position.

대표청구항 ▼

A combined stepladder and hand truck assembly is provided. The assembly comprises a first frame having two side rails, a second frame pivotally attached to the back side of the first frame and having two side rails, and a third frame pivotally attached to the front side of the first frame and having

A combined stepladder and hand truck assembly is provided. The assembly comprises a first frame having two side rails, a second frame pivotally attached to the back side of the first frame and having two side rails, and a third frame pivotally attached to the front side of the first frame and having two side rails. Steps and bars are provided so that they form a parallel link together with the side rails of the first frame. Two casters attached at the lower end of the first frame. A tool tray is provided at the lower end of the third frame. The tray is kept vertical to the frames when the assembly is used as a hand truck, and is kept horizontal when the assembly is used as a stepladder and the third frame is rotated upward to support the tool tray in a high position. t least one sensor adapted to sense one or more conditions indicative of the oxygen gas needs of the user, and a control unit interrelated with the air separation device and the at least one sensor to control the air separation device so as to supply an amount of oxygen gas equivalent to the oxygen gas needs of the user based at least in part upon the one or more conditions sensed by the at least one sensor. the minute holes flare outwardly in a direction extending from a top side to a bottom side of said mesh plate, and wherein a recess is formed in the top side of said mesh plate between mutually adjacent ones of the minute holes. 7. An ultrasonic atomizer according to claim 1, wherein cut-outs of different size are formed in the periphery of said mesh plate at least at two locations other than locations having point symmetry about the center of said mesh plate. 8. An ultrasonic atomizer according to claim 1, wherein said minute holes are formed at equal intervals along the sides of a plurality of regular hexagons having diagonals that vary at fixed distances. 9. An ultrasonic atomizer according to claim 1, wherein said mesh plate comprises a small area devoid of minute holes said small area being surrounded by said minute holes. 10. An ultrasonic atomizer according to claim 1, wherein said mesh plate comprises a small area devoid of minute holes, said small area opposing the opening in the upper end of the pump bore of said pump shaft over a region broader than said opening. 11. An ultrasonic atomizer according to claim 1, wherein said mesh plate comprises an annular plate at a peripheral portion of said mesh plate, wherein said annular plate causes the biasing force produced by said biasing member to be applied uniformly to said mesh plate. 12. An ultrasonic atomizer according to claim 1, further comprising a bush for encircling and supporting a portion of said pump shaft excluding upper and lower end portions of said pump shaft, said bush being liquid-tight; an annular lip seal, in liquid-tight contact with a portion of the pump shaft situated higher than said ultrasonic vibrator, said annular lip seal being formed integrally at least at two locations, one above the other, on an upper portion of said bush, and a gap being provided between said portion of the pump shaft and said bush between the annular lip seal at the at least two locations. 13. An ultrasonic atomizer according to claim 1, further comprising: a bush for encircling and supporting a portion of said pump shaft excluding upper and lower end portions of said pump shaft said bush being liquid tight; a housing into which said bush is fitted in a liquid tight arrangement; and a cap attached in a freely detachable manner to an annular projecting wall that is formed on said housing about the upper end portion of said pump shaft, said cap covering the upper end portion of said pump shaft when attached; a reservoir having (i) a bottom surface formed by a top side of said bush and (ii a peripheral wall formed by at least one of said cap and said annular projecting wall. 14. An ultrasonic atomizer according to claim 1, wherein a lower end of said pump shaft is disposed in close proximity to a bottom surface or side surface of said liquid vessel such that residual liquid remaining inside said liquid vessel is pumped upon attaching to the lower end of the pump shaft by surface tension. 15. An ultrasonic atomizer according to claim 1, wherein said liquid vessel is formed to have a recess for collecting the residual liquid remaining inside said liquid vessel, and the lower end of said pump shaft is disposed so as to face said recess. 16. An ultrasonic atomizer according to claim 1, further comprising: a drive circuit for driving the ultrasonic vibrator of said ultrasonic pump; an operating switch; first control means responsive to an on/off operation of said operating switch for controlling the driving of said ultrasonic vibrator by said drive circuit; and second control means for determining, in response to said operating switch being turned on and off at least one time, an OFF time for automatic intermittent operation based on the ON time and the OFF time of said operating switch, and for controlling said drive circuit such that said ultrasonic vibrator is driven using the ON time and the OFF time determined by said second control means. 17. An ultrason ic atomizer in which a liquid inside a liquid vessel is supplied to an inlet side of a mesh plate formed to have a plurality of minute holes and said mesh plate is vibrated by an ultrasonic vibrator, whereby the liquid supplied to the inlet side of the mesh plate is sprayed from an outlet side of said mesh plate, said mesh plate comprising a plate-shaped body having a recess between mutually adjacent ones of said minute holes, said plate-shaped body being formed such that peripheral wall surfaces of said minute holes project from the inlet side. 18. An ultrasonic atomizer according to claim 17, wherein said minute holes flare outwardly from the inlet side to the outlet side. 19. An ultrasonic atomizer according to claim 17, wherein cut-outs of different size are formed in the periphery of said mesh plate at least at two locations other than locations having point symmetry about the center of said mesh plate. 20. An ultrasonic atomizer according to claim 17, wherein said minute holes are formed in said mesh plate at equal intervals along sides of a multiplicity of regular hexagons having diagonals that vary at fixed distances. 21. An ultrasonic atomizer according to claim 17, wherein said mesh plate comprises a small area devoid of minute holes, said small area being surrounded by said minute holes. 22. An ultrasonic atomizer according to claim 17, wherein said mesh plate comprises a small area devoid of minute holes said small area opposing a liquid-supply port over a region broader than said supply port. 23. An ultrasonic atomizer comprising: an ultrasonic pump comprising a pump shaft having an upper end, a lower end, and a pump bore passing axially through said pump shaft to form openings in the upper and lower ends, said ultrasonic pump further comprising an ultrasonic vibrator mounted on said pump shaft substantially at a midpoint thereof with respect to the axial direction of said Dump shaft; a liquid vessel arranged such that it is penetrated by a lower end of said pump shaft; a mesh plate placed on a face of the upper end of said pump shaft, said mesh plate having a plurality of minute holes; a resilient biasing member for biasing said mesh plate toward the upper end face of said pump shaft; and an annular plate provided on a peripheral portion of said mesh plate, or a spacer provided between said mesh plate and the upper end face of said pump shaft, to cause the biasing force produced by said biasing member to be applied uniformly to said mesh plate. 24. An ultrasonic atomizer having an ultrasonic pump comprising a pump shaft formed to have a pump bore passing through it axially and having open upper and lower ends, and an ultrasonic vibrator mounted on the pump shaft in the vicinity of the midpoint thereof with respect to the axial direction, wherein a liquid inside a liquid vessel is pumped up from the lower end of said pump bore and the liquid is supplied to a mesh plate from the upper end of said pump bore so as to be sprayed, and wherein a bush is provided for encircling and supporting liquid tightly a portion of said pump shaft of said ultrasonic pump excluding upper and lower end portions of said pump shaft, an annular seal lip, in intimate liquid-tight contact with a portion of said pump shaft situated higher than said ultrasonic vibrator, is formed integrally at least at two locations, one above the other, on an upper portion of said bush, and a gap is provided between said portion of the pump shaft and said bush between said annular seal lips at the at least two locations. 25. An ultrasonic atomizer comprising: an ultrasonic pump comprising a pump shaft having an upper end, a lower end, and a pump bore passing axially through said pump shaft to form openings in the upper and lower ends, said ultrasonic pump further comprising an ultrasonic vibrator mounted on said pump shaft substantially at a midpoint thereof with respect to the axial direction of said pump shaft; a liquid vessel arranged such t