Abstract: A manual screwdriver includes a handle, a screwdriver head at a fore end of the handle, a spiral rod connecting with the screwdriver head, and an operating component coiling around the spiral rod. The handle defines a cavity and a slot communicating the cavity to exterior space. The slot is formed along an axial direction of the handle. The spiral rod defines a spiral groove thereon and being rotatably received in the cavity. The operating component includes an engaging block solidly embedded in the slot and a thimble extending through the engaging block. The thimble is driven by an external force to insert into the spiral groove of the spiral rid. The engaging block can slide along the axial direction of the handle via an elastic element to drive the spiral rod and the screwdriver head to synchronously and circularly rotate relative to the handle.

Abstract: A gasket installation fixture includes a shell and a positioning mechanism which is fixed on the shell. The positioning mechanism defines a pressing block and a transmission mechanism which is received in the shell. The transmission mechanism defines a slope and a guiding column which is received in the transmission mechanism, when the pressing block pushes against the slope, the transmission mechanism can slide in the shell to elastically deform and the guiding column can expand to hold and press the gasket into its place.