Abstract: Two posterior spinal fusion members are secured to a plurality of vertebrae which constitute a spine. The posterior spinal fusion members are fixed to both sides of the spinous processes of the vertebrae. A fixing instrument is attached to each posterior spinal fusion member. The fixing instrument includes a rod-shaped connecting member and two hooks slidably attached to both ends of the connecting member. Elongated holes are formed in the portions of the connecting member where the hooks are attached. Male screws are driven through the elongated holes. The surface around the opening of each elongated hole where the head of the associated male screw slides is formed as the bottom of a recess which is shallow on the associated end side of the fixing instrument and is deep on the connecting member side.

Abstract: An improved oil collecting vessel of the twin-hull type is described here. An oily water suction means is provided with a float that supported by a linkage mechanism which in turn is fixedly secured to an upper deck of the vessel. The oily water suction means may therefore be raised or lowered without changing its direction so as to follow the wave motion of the water surface region delimited at its opposite side edges by the hulls. Oily water floating on the water surface region is sucked through the oily water suction means and is conveyed to a tank in the vessel through a suction pipe. The suction of the oily water is enhanced by an ejector provided in the midway of the suction pipe. An effluent oil converging section is provided in a reentrant form in front of the oily water suction means and is delimited by guide plates on its opposite sides. In front of the oily water suction means is a jet water injection port.