This invention relates to means for starting and comprises the following improvements.
The admission of compressed air for starting is controlled, the compressed air being admitted to each working cylinder through a preliminary air chamber, the closing elements of which are controlled independently of each other during the working stage of the engine. The element regulating the admission of air from the preliminary air chamber to cylinder interior is actuated for each charge symmetrically to the dead centre positions so as to admit of variable charges, whereas the element controlling the supply of air from the air reservoir to the preliminary air chamber is actuated at and from the occurrence of the upper dead centre point for a constant charge, so that in the co-operation of the two controlling members the inflow of air to the starting valve is admitted by the controlling element governed in an invariable manner, and the air inlet proper to the working cylinder is regulated by the member or starting valve controlled in a variable manner.
The mechanism for effecting the above comprises a valve to control the air inlet in the working cylinder, in combination with a valve box connected to the working cylinder and of an air reservoir from which the passage of air to the cylinders is controlled by a valve actuated in an invariable manner by a cam on the controlling shaft which also operates the cam for actuating the inlet valve in the working cylinder.