US2294936A - Engine ignition mechanism - Google Patents

Description

Sept. 8, 1942. c. w. ROGERS ENGINE IGNITION MECHANISM Filed Aug. 26, 1940 Clifford W Snnentor 09 e rs & attorney] Patented Sept. 8, 1942 ENGINE IGNITION MECHANISM Clifford W. Rogers, Detroit, Mich, assignor to Rogers Motor Company, a common-law trust of Pennsylvania Application August 26, 1940, Serial No. 354,178

5 Claims.

This invention relates to internal combustion engines and particularly to ignition mechanisms for such engines.

An object of the invention is to provide an ignition mechanism particularly applicable to two-cycle engines and of an extremely simpleand reliable type.

Another object is to provide a make-and-break device for engine ignition circuits, disposing the contacts in a concealed and protected location tending to safeguard them from damage or tampering.

A further object is to make and break the ignition circuit of a two-cycle engine by a device comprising simply a contact rotative with the engine crank shaft and a companion contact fixed as regards such rotation.

These and various other objects the invention attains by the construction hereinafter described and illustrated in the accompanying drawing, wherein:

Fig. 1 is a front end view of an engine equipped with the improved ignition mechanism.

Fig. 2 is a view in side elevation of the lower portion of the engine.

Fig. 3 is an enlarged vertical sectional elevation of the lower portion of the engine, particularly showing the make-and-break device for the ignition circuit.

Fig. 4 is a cross section View of the make-andbreak device, taken on the line 44 of Fig. 3.

Fig. 5 is a cross sectional view taken on the line 5--5 of Fig. 3, showing another feature of the make-and-break device.

In these views, the reference character I designates the cylinder of a two-cycle engine, 2 a spark plug on the headed upper end of the cylinder, 3 a crank case surmounted by the cylinder, 4 a crank shaft extending at its driven end into the crank case, and 5 a connecting rod driven by a piston (not shown) operating in the cylinder and driving said shaft through engagement with the crank pin 6 of a crank disk 1, fast on the shaft. The latter is journaled in an elongated bearing 8 integrally projecting from the crank case.

My improved make-and-break device for the ignition circuit of the described engine comprises a split metallic collar 9 mounted on the outer end portion of the bearing 8, said end portion being preferably slightly reduced in external diameter to accommodate said collar. Fitted snugly within the collar 9 is an insulating bushing I0, the collar and bushing being both split to permit clamping them on the bearing.

The split ends of the collar are interconnected by a screw H, serving to regulably contract the collar and bushing so as to definitely restrain them from accidental rotation, while permitting their rotative adjustment. For applying such adjustment, the collar is integrally formed with an upstanding handle member I2. It is preferred to locate the split of the collar below the shaft 4 and to diametrically oppose the split of the bushing to that of the collar, so that the collar may exert a maximum leverage in contracting the bushing. The bushing projects slightly beyond the outer face of the collar and its projecting portion is cut away or otherwise segmental'ly recessed to accommodate a segmental contact plate 14, flush with the end face of the bushing, and spaced from the bearing 8, and electrically and me chanically connected to the collar 9, as by a screw l5 engaging the base of the handle member I2. The angular extent of the plate I4 is determined by the desired spark duration interval, approximately seventy degrees being preferred. It will be noted that the described mounting of the contact plate I4 adapts it to prevent relative rotation between the collar and bushing. Adjacent to its inner face, the collar 9 has an interior annular rib or flange I5a which coacts with the plate I4 to prevent any relative movement of said collar and the bushing l0 lengthwise of the shaft.

The shaft 4 projects outwardly beyond the bearing 8 to accommodate a driven member such as the propeller l6 and also a pair of collars l1 and I8 for clamping such member on the shaft. The collar H, which is closely adjacent to the bearing 8 is keyed to the shaft as indicated at I9, and the collar l8 engages the threaded outer end portion of the shaft. Drilled into that face of the collar I"! which opposes the bushing I0 is a socket slidingly receiving a small pin 20 and a coiled spring 2| urging said pin against the continuous face jointly formed by the bushing and contact plate M. A fiber bushing 22 snugly fits on the shaft between the collars I l and I8, serving to hold the inner collar in place upon removal of the outer collar and driven member. In absence of such bushing, the collar l1 would at such times tend to shift away from the bushing 8, allowing the pin 20 to drop out of its socket and possibly be lost.

When the engine is operating, the pin 20 contacts the plate I4 during a predetermined fraction of each revolution, thus accurately determining a periodic interval during which the usual ignition circuit (not shown) is closed and the spark plug takes effect. Rotative adjustment of the collar 9 by its handle member l2 advances or retards the spark as the situation may require. The pin 29 passes smoothly from the plate ii to the bushing l and vice versa, owing to the flush relation of the plate and bushing. The construction is extremely simple, particularly as compared to usual cam-operated make-and-break devices having exposed contact members. Concealed location of companion contact members I4 and 26 tends to safeguard them from damage and tampering. The spring 2| assures a suitable and constant contact pressure at all times.

What I claim is:

1. In an internal combustion engine, an ignition make-and-break device comprising a driven shaft, a bearing journaling said shaft, a split annular insulating member mounted on said bearing and having a surface substantially transverse to said shaft, a contact member carried by said insulating member and having a contact face substantially flush with said face of the insulating member, the insulating member being rotatively adjustable to shift said contact member about the bearing axis, a collar fixed on said shaft adjacent to said bearing, and a contact carried by said collar and resiliently pressed against said face, and means for regulably contracting said insulating member upon the bearing to oppose a predetermined resistance to rotation of said member.

2. In an internal combustion engine, an ignition make-and-break device comprising a driven shaft, a bearing journaling said shaft, a metallic collar mounted upon said bearing, a bushing inserted between said collar and bearing and electrically insulating the collar from the bearing, said bushing projecting at one end beyond said collar, a contact member carried by said collar and set into the projecting end of said bushing to form therewith an annular face substantially transverse to the shaft, a second collar fixed on the shaft adjacent to said bearing, and a contact carried by the second collar and resiliently pressed against said annular face.

3. In an internal combustion engine, an ignition make and break device comprising a driven shaft, a bearing journaling said shaft, a split metallic collar mounted upon and rotatively ad justable on said bearing, a bushing inserted be tween the collar and bearing and electrically insulating the collar from the bearing, said bushing being split at a point opposed substantially diametrically to the split of the collar, means for regulably contracting said collar to effect contraction of the bushing and thereby oppose a predetermined resistance to rotation of the collar and bushing, a contact member carried by said collar and set into the bushing to form therewith an annular face substantially transverse to the shaft, a second collar fixed on the shaft adjacent to said bearing, and a contact carried by the second collar and resiliently pressed against said annular face.

4. In an ignition make and break device, a bearing, a driven shaft journaled in said bearing and having an end portion projecting from the bearing, a collar mounted on and insulated from said bearing, a contact member, carried by said collar, a second collar keyed on said shaft adjaccnt t0 the bearing, a contact member mounted on the second collar and resiliently pressed toward the first collar to periodically engage the first-mentioned contact as the shaft rotates, a nut threaded terminally on said shaft for retaining a driven element on the shaft, and a bushing snugly fitted on the shaft between said nut and second collar and maintaining the working position of the second collar when the driven element is removed.

5. In an internal combustion engine, an ignition make and break device comprising a driven shaft, a bearing journaling said shaft, a metallic collar mounted on said bearing and rotatively adjustable about the axis of said shaft to advance or retard the spark, a bushing inserted between the collar and bearing and electrically insulating the collar from the bearing, said bushing having a track-forming face substantially transverse to the shaft, a contact member set into the bushing substantially flush with the track-forming face, a second collar fixed on the shaft adjacent to said bearing, and a contact carried by the second collar and having a brush engagement with the trackforming face, and means resiliently pressing said brush contact against the track-forming face.

CLIFFORD W. ROGERS.

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