GB597863A - Improvements in or relating to internal-combustion-operated percussion tools - Google Patents

Abstract

597,863. Power hammers. PHILIPPOVIC, J. W. May 11, 1944, No. 15624/46. Divided out of 597,812, [Group XXVII]. [Class 83 (iv)] [Also in Groups XXIII and XXVII] A percussive tool is operated by a two-stroke compression. - ignition internal - combustion engine in which the cylinder 16 has pistoncontrolled ports 36A, 36B, 37A, 37B, communicating directly with the atmosphere, the charge being induced by the outflow of the exhaust gas, the cylinder reciprocating over a fixed piston 14 to act as striker on an anvil 10 which carries the piston. The application to a pile driver is shown, in which the anvil 10 is attached to the pile, a cushion 45 of reinforced synthetic resin being preferably interposed. The piston 14 which carries a fuel nozzle 19 is mounted on a column 13 supported by the anvil 10. Fuel is supplied by a jerk pump 21 which is operated from the cylinder through a tappet 22 and striker 9 fixed to an adjustable ring 8. The fuel passes up a bore 25 in a rod 24, located in a centre bore of the column 13. A combustion chamber 30 in the cylinder head carries a hot refractory tube 32. Two divergent exhaust ports 36A, 36B and two convergent inner ports 37A, 37B are tangential and inclined towards the cylinder head, and spaced as shown. The space in the cylinder under the piston forms a recuperator chamber in which air is compressed at the top of the stroke, the chamber being vented on the return stroke by air passing a non-return valve 23. This air picks up lubricant from an annular reservoir 34. The anvil is guided as it descends by a spring- pressed wedge which keeps it in contact with a guide rail but which is put out of action when it is lifted. An eye 31 is provided for lifting the cylinder at starting. Specification 597,812 is referred to.