Abstract: An insect/dust-proof air shutter which can positively prevent intrusion of foreign mater such as insects and dust and further trap intruded insects is provided.

Abstract: An apparatus is provided for tensioning a drive belt, which apparatus consists of tensioner arm having an idler pulley thereon for engagement with the surface of a drive belt, structure for mounting the tensioner arm to a support for pivoting movement in first and second opposite directions relative to the support, and a torsion coil spring formed of wire and acting between the mounting structure and tensioner arm for biasing the tensioner arm in one of the first and second directions. The wire has a non-circular cross section.

Abstract: An apparatus for tensioning a belt consisting of a tensioner arm having an idler pulley for engagement with a surface of a drive belt, structure for mounting the tensioner arm to a suppport for pivoting movement about a pivot axis in first and second opposite directions, and structure for biasing the tensioner arm in one of the first and second directions. The mounting structure includes first and second members with first and second relatively movable cooperating friction generating surface for damping rotation of the tensioner arm. At least a portion of one of the friction generating surfaces is concave opening towards the tensioner with at least one of the friction generating surfaces having at least a portion defined by other than a radius centered on the pivot axis of the tensioner arm to thereby produce a greater resistance to rotation of the tensioner arm in the other of the first and second directions than in the one of the first and second tensioner arm pivoting directions.

Abstract: Apparatus for testing a power transmission drive intended for use with a reciprocating engine by use of an electric drive motor in lieu of the engine. The motor is provided in an adjustable input shaft driving unit which provides a variable speed drive of the power transmission drive correponding to a variable speed drive effected by a reciprocating engine. In one form, the drive speed is varied by a controlled brake which, in the illustrated embodiment, is an eddy current brake. The brake may be utilized in conjunction with a variable speed input shaft driving unit for providing a second speed variation or may be used independently thereof. Alternatively, the electric motor may be operated by a control arranged to provide a speed variation of the electric motor corresponding accurately with the reciprocating engine characteristics. Control circuity for effecting the desired brake control and motor control are disclosed.

Abstract: This invention involves manufacturing a conveyor belt by applying tension on a group of steel cords used as the belt tensile member, wrapping the tensioned steel cords with the rubber sheet to make a core body, sticking a based duck or a breaker and a covering rubber sheet in turn on said core body to build a belt, vulcanizing the belt and winding the resultant belt, in which the application of the tension to the group of steel cords is carried out by a plurality of pulleys on which hang a plurality of like weights respectively, and a winder.