578,825. Sawing - machines. ARMSTRONG, J. W. C., PALFI, J., and DANIELS, Ltd., T..H. & J. July 26, 1944, No. 14267. [Class 145 (ii)] The tension of a chain saw 1, Figs. 1 and 3, is adjusted by moving the blade 3 which supports the saw relatively to a fixed part of the machine by a rotatable eccentric arranged between that part and the blade. The blade 3, which may be of the construction described in Specification 578,826, is secured between the usual buffer plates 5, 6 by four bolts 11 having fixed thereto or integral therewith rectangular blocks 12 engaging slots 13 in the blade to guide the latter during its adjustment. This adjustment is effected by turning a cylindrical block 14, mounted in the buffer 6 and having an eccentric pin 24 engaging a vertical slot 25 in the blade 3. The block 14 has a reduced part 17 flattened to receive a spanner and carrying a screw 21 which, by engaging a locking bar 19 extending through a slot 18 in the part 17, holds the block 14 in its adjusted position. A serrated washer 23 engaging serrations on the block 14, holds the block against accidental turning. Specifications 568,988 and 578,824 also are referred to.