GB411568A - Improvements in or relating to piston or plunger valve arrangements for fuel pumps - Google Patents

Abstract

411,568. Fuel - injection pumps. THEGE, E. O. P., 59A, Hornsgatan, Stockholm, and CAMNER, H. G., Berglund, Ektorp, both in Sweden. Jan. 3, 1933, No. 152. [Class 102 (i).] In a fuel-injection pump for internal - combustion engines, byepass fuel is discharged through a passage formed by recesses 18, 19, 20, some being axially spaced along a reciprocating member 6 and others corresponding to them being formed in the pump casing, these recesses being so arranged so that several slide valve closures x are interposed between the pump chamber 14 and the outlet passage 15. In the Figure the member 6 which acts also as the piston of the pump is reciprocated by a tappet 5 actuated by a cam or eccentric on the driving shaft 1. The stroke of the piston 6 is adjustable by means of an eccentric 10 which raises or lowers a lever 9. On the discharge stroke fuel is discharged past a valve 13 until the recess 18 communicates with the recess 20. Simultaneously the recess 19 communicates with the passage 15 and the recess 20. Fuel then passes through an axial passage 16 and radial passages in the piston, to the recess 18 and thence via recesses 20, 19 to the outlet 15. The mating recesses 19, 20 are longer than the stroke of the piston and the surfaces x. In a modified form, two such sets of mating recesses 19, 20 and three closures surfaces x are provided. In another modification, the recesses in the pump piston have edges oblique to its axis so that a higher or lower point first comes into contact with the corresponding recess in pump casing according to the angular position of the piston. The latter is angularly adjusted by worm gearing either manually or by a governor. In another modification, the reciprocating member 6 is separate from the pump piston but is driven in unison with it. This member has oblique edged ports as in the previous modification, but is angularly adjusted by a hand lever.