Abstract: A gas density relay check device and a check method thereof are provided. In check, a temperature adjusting mechanism and a gas density relay are relatively set. Temperature rise and fall of a temperature compensation element of the gas density relay is adjusted through the temperature adjusting mechanism, then the gas density relay is enabled to have a contact signal action. A gas density value is obtained according to the pressure value and the temperature value in the contact action. A contact signal operating value of the gas density relay is detected to check on the contact signal operating value of the gas density relay. The gas density relay check device of the present disclosure is capable of accurately checking gas density relays, and is particularly applicable to a gas density relay without a three-way valve, and check can be achieved without disassembling the gas density relay.

Abstract: The present disclosure relates to a folding chair framework, including a connecting seat, a guide rod, a guide sleeve, several chair legs, several supporting rods, several connecting rods, a first spring, a second spring, and wedge-shaped blocks; upper ends of the chair legs are all hinged with the connecting seat; the guide rod is vertically arranged and connected to the connecting seat; the guide sleeve is slidably connected to the guide rod; each connecting rod is hinged with the guide sleeve and one chair leg respectively; upper and lower ends of the first spring are respectively connected to the connecting seat and the guide sleeve; the wedge-shaped blocks are slidably connected into first grooves of the guide rod; two ends of the second spring are respectively connected to the first grooves and the wedge-shaped blocks; the guide sleeve includes an inner sleeve and an outer sleeve.

Abstract: The present disclosure relates to a folding chair framework, including a connecting seat, a guide rod, a guide sleeve, several chair legs, several supporting rods, several connecting rods, a first spring, a second spring, and wedge-shaped blocks; upper ends of the chair legs are all hinged with the connecting seat; the guide rod is vertically arranged and connected to the connecting seat; the guide sleeve is slidably connected to the guide rod; each connecting rod is hinged with the guide sleeve and one chair leg respectively; upper and lower ends of the first spring are respectively connected to the connecting seat and the guide sleeve; the wedge-shaped blocks are slidably connected into first grooves of the guide rod; two ends of the second spring are respectively connected to the first grooves and the wedge-shaped blocks; the guide sleeve includes an inner sleeve and an outer sleeve.