Abstract: The invention provides a knob with safety button for a domestic gas that includes a gas valve. A stem is integrated with the gas valve, which is pressed by the knob to press and to simultaneously rotate the stem of the gas valve for opening and regulating the flow of gas through of the valve. The improvements comprising a safety button coupled with the knob, the button being connected by one end with the stem of the valve, for avoiding that the valve be operated in a turn condition when the knob is only pressed, or for facilitating the turn of the knob when the safety button is pressed.

Abstract: A device suited for dispensing a dental substance comprises a cartridge 20 or receiving the substance, with a curved dispensing nozzle 22 disposed at the front end and a flange 21 of octagonal cross-section provided at the rear end of the cartridge. The flange 21 serves to engage a slide-in socket 16 of an applicator 10 which includes a piston rod 12 for advancing a dispensing piston 23 disposed in the cartridge 20. In the retracted position of the piston rod 12, the cartridge 20 may be laterally inserted into the slide-in socket 16 of the applicator 10. The socket has two parallel walls spaced by a distance which is between the largest and the smallest diameter of the octagonal flange 21.