Improvements in and relating to a method of fixing crank shafts in grinding machines, and improvements in and for crank shaft grinding machines, and centering apparatus for use in the carrying out of the method

摘要

621,036. Grinding crank shafts. HANSEN, A. E. Nov. 14, 1945, No. 30421. Convention date, Feb. 2. [Class 60] [Also in Group XXII] A method of fixing crank shafts in grinding machines, in which the crank shaft during the grinding of the connecting rod bearing journals is clamped with its outermost main bearing journals each to its face plate or corresponding fixing means, is characterized in that the connecting rod bearing journals to be ground in the particular fixing are first, independently of the face plates or the corresponding fixing means, centred so that their centre line coincides with the mutual axis of rotation of the latter (the centre line of the grinding machine), after which the two outermost main bearing journals are clamped to the face plates or the corresponding fixing means in their position in relation thereto determined by the centreing of the connecting rod bearing journals. A centreing bracket, Fig. 2, includes a part 2 slidably mounted on a horizontal keyway 13 on a part 1 and having a vertical centreing fork 7 slidable vertically on the said part 2 at a fixed distance B from a vertical plane surface 4 formed on the said part 2. A horizontal centreing fork 16 is fixed on the part 1 at a height H above plane surfaces 21, 22 formed on the said part and resting on a plane horizontal face of the machine table. In use, connecting rod bearing journals 9 are pressed into contact with the legs of the fork 16 by a finger 18 carried by the part 1, and the fork 7 is then moved vertically and its carrying part 2 horizontally until both legs of the fork 7 contact the journal 9. The parts 1 and 2 are then locked together by a bolt 14 and the bracket and the crankshaft moved so that the surface 4 engages a vertical side edge of the machine table. When the connecting rod bearing journals have thus been centred, the outer main bearing journals 34 are fixed to their face plates 24, Fig. 6, by means of clamps 33 carried on slides 30 adjustably fixed in diametral T grooves 25 in the face plates 24. The centreing forks need not be vertical and horizontal, and according to the manner in which the connecting rod bearing journal is placed in the forks it can either be ground so that the minimum amount of material is removed or so that the original centre is kept.