816,754. Centrifugal governors. HEINZMANN, F. Oct. 8, 1956 [Oct. 15, 1955; July 25, 1956], No. 30543/56. Class 57. A centrifugal governor for internal-combustion engines comprises pivotal flyweights 3 opposed by radial springs 4 and acting on a control-rod 9 whose loading is variable during operation by adjustable torsion spring means controlled by a manually-operative speed control lever. A ball-bearing 10 secured to the rod 9 carries a cup 11 having two grooves engaged by sliding trunnions 12 pivotally connected to a forked lever 13 keyed to a regulating-shaft 14. The torsion-spring means comprises two springs adapted to come into operation successively and in the arrangement shown in Fig. 2 a torsion coil spring 16 is screwed at one end to the shaft 14 and at the other to the manually operative speed-control lever 17, rotatably mounted in the governor casing 15, and a torsion bar 18 is fixed at one end to the shaft 14 and at the other to a bush 19 journalled in the lever 17 and rotatably adjustable therein by a cap 20 adjustably secured to the lever 17 by screws 22 passing through an arcuate slot in the cap and having a pin 23 contacting a screw 24 in the bush 19. The lever 17 is secured in position, when the torque in the springs has been set to the desired amount, by nut 26 of bolt 25 passing through an arcuate slot in casing 15. A tube 28 is fixed at one end to the shaft 14 and has its other end journalled in the lever 17 from which a pin 29 extends normally with clearance into a recess in the tube. When the lever 17 is moved to the stop position, the pin 29 engages and rotates the tube and thereby the shaft 14 against springs 4 to close down the governed engine. In a modification, Fig. 4 (not shown), the spring 16 is replaced by a torsion bar in the form of a number of plate-springs. In a further modification, Fig. 3 (not shown), the torsion-bar 18 is fixed to the lever 17 and the spring 16 is screwed to a bush rotatable with the lever through a lostmotion connection. In a further modification, Figs. 6 and 7, the flyweights 3 are loaded by concentric radial springs 37, 41 arranged to operate successively and a regulating lever 45, slidably connected at its forked end to the bearing cup 42 on the control-rod 9, is pivoted on a pin 46 displaceable against a spring 48 by a lever 49 pivotally connected to the casing by a bolt 50. The end of the lever 49 remote from the pivot pin 46 is slotted to engage a bolt 52 on a bush 53 secured to a shaft 54 on which is pivotally mounted a lever 55 loaded by torsionsprings 58 and 59 to contact the bearing-cup 42. The springs 58 and 59 are screwed at one end to a bush 56, press-fitted in a ring 60 having a pin 61 engaging a lug 62 on the lever 55, and at their other ends to the manually operative speedcontrol lever 63 and a bush 57 respectively. The bush 57 is rotatably seated in the lever 63 and has a screw 64 extending into an arcuate slot in a ring 65 secured to the lever 63, together with a cap 68, by screws 69 passing through arcuate slots in the cap and ring. A pin 70 on the cap 68 engages a pin 71 on the shaft 54 so that during intermediate speed ranges the regulating lever 45 and thus the governed engine is controlled solely by the lever 63 through lever 49. At higher speeds movement of the lever 49 is prevented by a stop 73 and movement of lever 63 in the opening direction tensions first spring 58 and then spring 59. At idling speeds the governor is loaded by springs 37 only.