GB265184A - Improvements in armature actuating mechanism for magnetos - Google Patents

Abstract

265,184. Brown, P. Jan. 28, 1926, [Convention date]. Inductor machines; reciprocating and oscillating machines.- In an inductor magneto machine in which an armature bar is moved from and into contact with the magnet poles, the removal is initiated at an adjustable time by inelastic driving means and is continued, adjustably in respect of time and driving force, by elastic driving means, the force being decreased by timing the device when the spark is advanced. Figs. 1 and 3 show the device set respectively for advanced and retarded sparking and Figs. 4 and 6 are sectional detail views on the planes 4-4, Fig. 1, and 6-6, Fig. 4. Fig. 5 is a section on the plane 5-5, Fig. 4. The type of magneto illustrated comprises permanent magnets m, Fig. 1, the polepieces c of which carry primary choke windings w and secondary windings w' connected to the spark plugs. The poles are intermittently bridged by the armature bar a which is reciprocated from the engine cam or other shaft 43 by an eccentric, push-rod 39 and crank 12, and at the same time opens and closes contacts b<1> in the circuit of the coils w. The crank 12, which reciprocates the armature through its forked end and a sliding block pivoted in the armature stem 10, is journaled on a spindle 17 projecting eccentrically from a shaft 18 which is housed in a bearing 21, Fig. 5, on the magneto-supporting frame f. An extension 19 of this shaft carries the pendent timing-lever 20 on an arm 34 of which is one abutment, in the form of an adjustable screw 31 in the end 32 of the arm, for the armature driving spring 28. The other end of this spring abuts on the bent end 27 of a finger 26 which projects from the downward arm 16 of the crank member. Thus, when the lever 20 is moved to the retard-spark position, Fig. 3, the i compression of the driving spring 28 is increased, while it may be independently controlled by means of the screw 31. The setting of the lever 20 is held by a projection 22, Fig. 5, which is urged by a sunk spring 25 into one of a series of notches 23 on the framing. The arm 16 of the crank is bored conically for the passage of the push-rod and has bosses respectively engaged by the shoulder 45 of the push-rod and the return spring 46 which is carried on the outer end of the push-rod. The push-rod is adjustably screwed into the eccentric stem so that by adjustment of its lock nut 41 and of the abutment screw 31 of the spring 28 or by adjustment of the timing lever the movement of the armature may be effected entirely by the shoulder 45 or it may be initiated by the shoulder and completed by the spring 28 for starting or at low engine speeds. When the spark is retarded, the combination of inelastic and elastic drives for the armature is employed, and at high speeds with advanced spark and the spring 28 unstressed, an inelastic drive from the shoulder 45 only is used. Alternatively, for lower speeds, the spring 28 may be made to give the complete drive without using the shoulder. The return spring is so set as to take up lost motion and eliminate noise.