Abstract: A orthodontics bracket has a bracket body, an arch wire slot formed on the bracket body, an opening/closing lid for locking an arch wire, and a opening/closing lid connecting part for connecting the opening/closing lid to the bracket body in a slidable and rotatable state. The opening/closing lid is capable of moving along a movement path that passes through a closed position at which it is engaged to the bracket body in a state of blocking the arch wire slot, an disengagement position at which it has slid from the closed position and disengaged from the bracket body, and an open position at which it has rotated from the disengagement position and the arch wire slot has been uncovered. The opening/closing lid for locking the arch wire closes in a reliable manner and does not accidentally open, and can be readily operated so as to open or close.

Abstract: An individual resin core used for a bracket fitting method of an orthodontic appliance includes an advance potion packed between a base of a bracket and a tooth and a core portion extending from the advance portion and covering a portion up to a cut edge of the tooth or occlusal surface. The core is individually formed for each tooth. Because this individual core has a low flexibility and is divided for each tooth, distortion and floating do not occur when it is fitted to the tooth of a patient, and the bracket can be bonded correctly. Since the resin core is independent of the alignment of teeth, it can be formed on a set up tooth impression. Since the bracket need not be returned to an original impression mold, technical work that would otherwise be necessary can be eliminated.

Abstract: A valve operating device for operating an intake or exhaust valve in an internal combustion engine includes a cam having a cam profile including a valve lifting portion for applying a force to open the engine valve and a base circle portion for allowing the valve to be closed, the cam profile having a valve opening point and a valve closing point between the valve lifting portion and the base circle portion, a cam follower slidably engaging the cam, and a hydraulic lash adjuster combined with the cam follower for eliminating any gap between the means and the engine valve. The base circle portion has a gradient cam surface or a combination of different gradient cam surfaces for canceling out valve-lifting radial displacement of the base circle portion.

Abstract: A hydraulic circuit for a valve operation timing control device for an internal combustion engine which has a low-speed cam having a shape suited for low-speed operation of the engine, a high-speed cam having a shape suited for high-speed operation of the engine, the low- and high-speed cams being integrally formed on a camshaft rotatable in synchronism with a crankshaft, a first rocker arm held in slidable contact with the low-speed cam, a second rocker arm held in slidable contact with the high-speed cam. The first and second rocker arms are adjacent to and in slidable contact with each other and pivotably supported on a rocker shaft for relative angular displacement. There is a first oil feed passage for lubricating the low-speed cam and a second oil feed passage for lubricating the high-speed cam.

Abstract: A valve operating mechanism for an internal combustion engine has a low-speed cam for operating the intake or exhaust valves during low-speed operation of the engine and a high-speed cam for operating the intake or exhaust valves during high-speed operation of the engine. A low-speed lubricating oil passage is provided for supplying lubricating oil to the low-speed cam and a separate high-speed lubricating oil passage is provided for supplying lubricating oil to the high-speed cam. A control valve is connected to said low-speed and high-speed lubricating oil passages for selectively supplying maximum oil pressure to the high-speed lubricating oil passage during high-speed operation while restricting the rate of flow of oil during low-speed operation of the engine and supplying maximum oil pressure to the low-speed lubricating oil passage during low-speed operation of the engine while restricting or eliminating the oil supplied thereto during high-speed operation.

Abstract: Oil is supplied from an oil pump as working oil to hydraulic lash adjusters and also as lubricating oil to journals and cams of a camshaft. The oil passage system includes a first supply passage connected to the oil pump, a second supply passage connected between the first supply passage and a first distribution passage coupled to a group of hydraulic lash adjusters, a joint passage connected to the first distribution passage, and a second distribution passage coupled to the joint passage and connected to another group of hydraulic lash adjusters. The second distribution passage is connected by air vent passages to a lubricating oil passage which supplies the camshaft with the lubricating oil. The joint passage is connected to one of the camshaft journals by a relief passage having a relief valve.