Abstract: An assembly for coupling a valve stem to an actuating member of an actuator in a desmodromic valve actuation mechanism comprises a spherical bearing having two portions each of which defines a respective bearing surface which is complementary to the bearing surface defined by the other portion, at least one of the surfaces being part spherical, one of the portions being arranged to be coupled to the actuating member and the other portion being arranged to be coupled to the valve stem; and a resilient arrangement which exerts a biasing force on one of the bearing portions and provides resilience in the coupling provided by the assembly between the valve stem and actuating member.

Abstract: An assembly for coupling a valve stem to an actuating member of an actuator in a desmodromic valve actuation mechanism comprises a spherical bearing having two portions each of which defines a respective bearing surface which is complementary to the bearing surface defined by the other portion, at least one of the surfaces being part spherical, one of the portions being arranged to be coupled to the actuating member and the other portion being arranged to be coupled to the valve stem; and a resilient arrangement which exerts a biasing force on one of the bearing portions and provides resilience in the coupling provided by the assembly between the valve stem and actuating member.

Abstract: A belt for training abdominal muscles comprises means (103) for determining a base girth of a user. Means (115, 117, 119) is also provided for determining changes in girth of the user as a result of contraction and relaxation of the user's abdominal muscles. Further means (125) provides feedback to the user as to the extent of contraction of the user's abdominal muscles, the feedback being displayed as a continuous, progressive indication of the degree of contraction of the user's abdominal muscles. A training method employs the belt and comprises the steps of: placing the belt around the waist of a user and determining a base girth of the user. The user's abdominal muscles are contracted and relaxed so as to provide feedback to the user as to the extent of contraction of the user's abdominal muscles, and a continuous, progressive indication of the degree of contraction of the user's abdominal muscles is noted.

Abstract: A respiratory protection device comprises a housing (1) defining a chamber within the housing. The chamber is open in a region which in use is adapted to be nearest to a user. A porous element (3) is located within the chamber and a communicating member (5) communicates with the porous element (3) within the chamber.