Abstract: A release valve for a lifting device includes a valve stem, a fixing seat, a spiral spring, and a knob. The valve stem includes a first conical end mounted in an oil path of the lifting device, a mediate portion, and a second end beyond the lifting device. The valve stem further includes a threaded section in threading engagement with the lifting device. The fixing seat is mounted around the mediate portion of the valve stem and is beyond the lifting device. The fixing seat includes a boss formed on a first side thereof, a central through hole extending through the fixing seat and the boss. The boss includes a longitudinal slit defined in a periphery thereof. The spiral spring is mounted around the boss of the fixing seat. The spiral spring has an inner end which is securely received in the longitudinal slit of the boss and an outer end. The knob is securely mounted around the second end of the valve stem to rotate therewith.

Abstract: A portable electric pump and illuminating/alarm device includes a main body housing, an illumination lamp mounted to the main body housing to illuminate in a front direction, two alarm lamps respectively mounted to two lateral sides of the main body housing to illuminate in a lateral direction, a pressure gauge mounted to the main body housing, an air outlet nozzle, a plug for electrical connection with an external power source, and switches for controlling on and off of the illumination lamp and alarm lamps as well as the air outlet nozzle.

Abstract: A screw jack includes a pair of frames disposed between a pair of walls, a bracket disposed above the beams, and a bolt engaged between the lower ends of the frames. An actuating device is engaged with the bolt and includes a motor for rotating the bolt so as to move the lower ends of the frames toward each other or away from each other and so as to elevate the bracket. The bracket can be easily move up and down by the motorized actuating device.

Abstract: A screw includes a drill point formed on a root portion of a threaded shank of the screw having a plurality of helix flutes helically formed in the screw emerging from the drill point through the threaded shank and a plurality of packing rings annularly secured on the shank so as for a firm fixation of the screw in a wall or article to be fastened without being pre-drilled by a drill tool.