US1231043A - Ignition system. - Google Patents

Description

C. T. MASON.

IGNITION SYSTEM.

APPLICATION FILED 00121. I916.

' 1,231,043. 7 Patented June 26,1917.

3 SHEETS-SHEET 1' C. T. MASON.

IGNITION SYSTEM.

APPLICATION FILED OCT. 21. I916.

1,231,043. Patented June 26, 1917.

3 SHEETS-SHEET 2.

C. T. MASON.

IGNITION SYSTEM.

APPLICATION FILED 0CT.2I. I9l6.

1 ,23 1 ,043 Patented JIme 26, 1917.

3 SHEETSSHEET 3- UNITED STATES PATENT OFFICE.

CHARLES THOMAS MASON, 0F SUMTER, SOUTH CAROLINA, ASSIGNOR TO SPLITDORF ELECTRICAL COMPANY, OF NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

IGNITION SYSTEM.

Specification of Letters Patent.

Patented J 11110 26, 191'7.

To (ZZZ whom it may concern:

Be it known that I, CHARLES THOMAS MASON, a citizen of the United States, residing at Sumter, in the county of Sumter and State of South Carolina, have invented certain new and useful Improvements in Ignition Systems, of which the following is a specification, reference being had to the ac companying drawing.

The invention relates to new and useful improvements in ignition systems, and more particularly to an ignition system for a high tension, high speed magneto.

In my prior application, Serial No. 37,130, filed June 30, 1915, I have described at length an ignition system for magnetos wherein an interrupter is used having a plurality of pairs of contacts, which contacts are so actuated that they act in alternation, and each pair of contacts completely and 1ndependently controls the discharge through the discharge circuit. The present invention relates to an ignition system of the above type, an object of the invention being to provide an interrupter mechanism wherein the contacts are actuated from cams formlng a part of the rotor.

A further object of the invention 1s to provide an ignition system of the above character wherein the interrupter levers are mounted on the field structure and are shiftable with the same for timing purposes.

A still further object of the inventlon 1s to provide an ignition system-of the above character wherein the interrupters are not only actuated by the rotor or. cams mounted thereon, but said interrupters are positioned inside of the magneto casing and cover by a removable portion of the casing so that access may be readily had to the interrupter mechanism for adjustment purposes.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings, which show by way of illustration one embodiment of the invention:

Figure 1 is a side view of a magneto with the cover. plate removed so as to show the interrupters; i

Fig. 2 is an end vie w of the magneto with a part of the casing broken away;

Fig. 3 is a sectional view on the line A"A of Fig. 1, looking in the direction of the arrow;

Fig. 4 is a sectional view on the line B-B of Fig. 1, looking in the direction of the arrow;

Fig. 5 is a diagrammatic view showing the two interrupters, the magneto rotor, and the connections to the interrupters;

Fig. 6 is a view showing the cam actuating surfaces for the interrupter levers as viewed from the end of the rotor and their relative positions to each other.

In carrying out the invention, I employ a magneto which may be of any suitable type, although I prefer to use a magneto of the well-known Dixie type. Such a magneto is provided with a rotor which is mounted to rotate between the poles of a permanent magnet. Associated with the rotor is a current generatingcoil which is carried by a field structure which is normally stationary but which may be shifted for timing purposes. The magneto is also preferably of the type wherein four spaced prongs are used whereby four current changes are produced in the generating coil for each revolution of the rotor. The primary circuit is interrupted for the purpose of causing a current in the secondary. In order to prolong the length of time that the contacts of the interrupter are open, I employ two pairs of contacts which act in alternation and each pair of contacts completely and independently control the discharge. First one pair of contacts will open, and then the other pair will open, and while the second pair is open, the first will again close and open and then the second pair will close and open while the first pair is open and so on, the contacts first one and then the other becoming efijective to control the discharge. The interrupter levers actuating the contacts are mounted on suitable lugs carried by the field structure. These levers may be initially set on the field structure so as to open at the proper point on the E. M. F. wave in the generating coil, and when once properly set they will always maintain their correct position for breaking the circuit so as to produce a maximum spark. These levers are shifted with the field structure and, therefore, maintain their proper timing so as to give maximum spark for all positions of adjustment, either when the spark is advanced or retarded. The interrupters are mounted withm the magneto casing and are inclosed by a suitable cover plate so that they are readily accessible for adjustment.

Referring more in detail to the drawings:-

My improved ignition system is embodied in a magneto indicated at 1 in the drawings. Said magneto, as above noted, is preferably of the well-known Dixie type wherein the rotor, indicated at 2 in the drawings, is carried by the shaft 3, and this rotor has its longitudinal axis extending through the poles of a permanent magnet. The rotor, as shown in the drawings, is provided with four prongs or arms, indicated at 4-4c and These prongs or arms are arranged in quadrature. The prongs or arms t-iland 5 5 are carried respectively by the magnetic members (3 and 7. The rotor is so built up that the members 6 and 7, together with the prongs carried thereby, are insulated from each other and the two parts are separated by a non-magnetic block. This structure is well-known in the magneto art, and further description thereof is not thought necessary.

Associated with the rotor is a field structure which is shown in section in Figs. 3 and at and indicated by the reference numeral 8. Said field structure has upstanding pole pieces 9 and 10. This field structure is mounted so as to freely oscillate about the center of the shaft 3 as an axis, and said structure is shifted by a hand lever 11.

Mounted upon the field structure are two fixed contacts 12 and 13 which are electrically connected by means of a bar 14. This bar is supported by screws and insulating bushings, indicated at 15 and 16 respectively. The contacts 12 and 13 are of the usual construction and are detachably connected to the supporting bar 14.

Mounted on the field structure are interrupter levers 17 and 18. These interrupter levers are each provided with a contact, and these contacts carried by the interrupter levers cooperate respectively with the contacts 12 and 13. The field structure is provided with a suitable projecting lug 19 by which the interrupter lever 17 is pivotally supported. A bolt 20 is secured to the lug 1!) by means of a nut 21, and this bolt is shouldered so as to form a bearing abutment for the lever, and the lever may be held on the shouldered bolt by any suitable means. Also mounted on the field structure is a lug 22, and the lever 18 is pivotally supported by said lug 22 through a bolt 23 and a nut 24. These interrupter levers are normally held in yielding engagement with the contacts 12 and 13 respectively by springs. These springs are indicated at 25 and 26. Each spring is secured to the field structure by a screw 27 and is connected to the interrupter lever by a screw 28.

The inner end of the interrupter lever 17 is provided with a bumper 29, while the inner end of the interrupter lever 18 is provided with a bumper 30. The field structure is cut-away and the bumpers extend through the ci'it-away portions in the field structure. The member 7 of the rotor is formed with two concentric faces a;-0., and two cam surfaces 7)Z). The bumper 29 of the interrupter lever 17 is adapted to be engaged by the faces (41 (t and bb of the member 7. lVhen the faces (6(t are in engagement with the bumper 29, as indicated in Fig. 5, then the contacts are separated, but when the sections Z)7) are underneath the bumper, then the spring will cause the contacts to come into engagement. The member (5 is provided with concentric faces 0-c and cut-away cam surfaces (Z (Z. The concentric faces 0 0 hold the contacts separated, while the cut-away cam faces (Z-(Z permit the contacts to come into engagement.

As clearly shown in Figs. 5 and (3, these cam actuating faces on the rotor are so positioned relative to each other that the contacts are operated in alternation. Considering the rotor to be turning in the direction of the arrow X in these figures, it will be noted that both contacts are open and will be held open until the cut-away portion (Z releases the interrupter lever 18, then the contacts at the left, as viewed in this figure, will close. The concentric faces a of the member 7 are of sufficient length that the contacts at the right will remain open until the concentric surface 0 comes underneath the bumper on the interrupter lever 18 and separates the contacts controlled thereby. This concentric surface 0* will hold the interrupter lever 18 with the contacts open until the cut-away surface 7) passes underneath the bumper 29 which permits the contacts at the right in Fig. 5 to close and open again. It will thus be apparent that the cam surfaces are so constructed and disposed relative to each other as to not only operate the contacts in alternation, but to open one contact and hold it open until the other has closed and opened again, and then the second pair just referred to will remain open until the first pair has closed and opened again, and so on so that each pair of contacts completely and independently controls the discharge.

For each rotation of the rotor, each pair of contacts will be closed and opened twice, and there will be four discharges produced in the current generating coil. WVbile I have, therefore, multiplied the number of discharges in the current generating coil. over that produced by the two prong rotor, still each pair of contacts will only be opened the same number of times that they would have been opened in connection with a two prong or arm rotor. It will be obvious that the number of interrupter-s and contacts con trolled thereby may be multiplied, if desired, and thus the number of operations of one pair of contacts, althoughthe speed of the rotor may be very high, will not be so great but what ample time is given to per- Init a proper spark and ignition of the charge of gas thereby when said ignition system is used in connection with an internal combustion gas engine.

In Fig. 5 of the drawings, I have shown, more or less diagrammatically, the connections betweenmy improved ignition'system and a multiple cylinder gas engine. It will be understood that the member 7 is always of one polarity, for instance N, while the memher 6 is of the S polarity with the result that during their rotation the magnetic flux from the permanent magnet, which embraces the ends 6 and 7, is conducted to the pole pieces 9 and 10 and passes through the core 31 of the wings indicated at 32 in Fig. 1 of the drawings, thereby generating current in the well-known manner. It will be understood that the windings of this coil 82 consists of the usual primary winding 33 and the secondary winding 34. A condenser 35 of proper capacity is connected across the primary winding, as shown in the diagram in Fig. 5, for the purpose of eliminating the spark at the interrupter contacts. The secondary current generated in the winding 84 is conducted to a distributer which may be of any desired type and which is indicated at 36 in Fig. 5 of the drawings. From the distributer the current is distributed to the several spark plugs which are indicated at 37. The contacts 12 and 13, as above noted, are electrically connected to the bar 14, and this bar is'connected to the primary 33 of the current generating coil.

The entire field structure, as above noted, carrying the interrupter levers and the fixed contacts which cooperatetherewith is movable about the aXis of the rotor by means of the hand lever '11 for timing purposes. The rotor is connected to the engine shaft and remains in a fixed timed position relative to the engine shaft. When the field structure is shifted, the time interval in which the bumpers are engaged by the actuating cams will either be advanced or retarded, depending on the direction of shifting of the interrupter levers. Whatever may be the angle of advance or retard of the spark, however, the pole faces will be likewise shifted through a similar angle and, therefore, the contacts will open at the proper point on the E. M. F. wave in the generating coil for maximum discharge.

It will be noted from the above that the interrupter levers and the actuating cam surfaces therefor, also the contacts controlled by the levers, are all located within the casing of the magneto. The casing is provided with an opening, indicated at 38, and this opening is closed by a cover plate 39 which is secured to suitable lugs 10. By removing the cover plate, access may be readily had to the interrupter levers and contacts for adjustment purposes. lNhile I have shown the actuating cam surfaces as located at the opposite ends of the rotor, it will be understood that the interrupters and actuating cams therefor may be otherwise disposed, the essential feature being that the interrupters shall be operated by a section of the rotor, and preferably an integral section thereof, and that the interrupter levers should be mounted on the field structure so that the same are adjustable with the field structure.

It is obvious that minor changes in the details of construction and the arrangement of parts may be made without departing from the spirit of this invention, as set forth in the appended claims.

Having thus described the invention, what is claimed as new is 1. An ignition system including a mag neto having a generating coil, a rotor, a discharge circuit connected to said coil, and an interrupter comprising a plurality of pairs of contacts, said rotor having a section thereof shaped to form cam surfaces for actuating the contacts, the cam actuating surfaces for the respective contacts being so disposed that said pair of contacts act in alternation and each pair of contacts completely and independently control the dis charge.

2. An ignition system including a magneto having a generating coil, a rotor, a discharge circuit connected to said coil, and an interrupter comprising a plurality of pairs of contacts, said rotor having an integral section thereof shaped so as to form cam surfaces for actuating the contacts, the cam surfaces for the respective contacts being so disposed that said pair of contacts act in alternation and each pair of contactscompletely and independently control the discharge.

3. An ignition system including a magneto having a generating coil, a rotor, a discharge circuit connected to said coil, and. an interrupter comprising a plurality of pairs of contacts, said rotor having a section at each end thereof formed with a cam surface, said cam surfaces actuating respectively the contacts, and said cam surfaces being so disposed relative to each other as to cause said contacts to act in alternation and each pair of contacts to completely and independently control the discharge.

4;. An ignition system including a magneto having a generating coil, a rotor, a field structure associated with the rotor and carrying said generating coil, a plurality of interrupter levers carried by said field structure, pairs of contacts controlled by the respective interrupter levers, said rotor having a cam surface cooperating respectively with each interrupter lever, said cam actuating surfaces being so disposed that said pairs of contacts act in alternation and each pair of contacts completely and independently controls the discharge.

5. An ignition system including a magneto having a generating coil, a rotor, a field structure having pole pieces associated With said rotor, said field structure carrying said generating coil, means for shifting the field structure relative to the rotor for timing purposes, interrupter levers movable with said field structure, pairs of contacts controlled respectively by the interrupter le-,

vers, said rotor having cam surfaces cooperating respectively with the interrupter levers, said cam surfaces being so disposed as to actuate said interrupter levers in alternation.

6. An ignition system including a magneto having a generating coil, a rotor, afield structure having pole pieces associated with said rotor, said generating coil being mounted on said field structure, interrupter levers mounted on said field structure, pairs of contacts controlled respectively by said interrupter levers, said field structure having cut-away portions adjacent the free ends of said interrupter levers, a bumper connected to each interrupter lever and adapted to extend through its respective opening in the field structure, said rotor having cam surfaces formed therein adapted to cooperate respectively with the bumpers for actuating the interrupters.

7. An ignition system including a magneto having a generating coil, a rotor, a field structure having pole pieces associated With said rotor, said generating coil being mount ed on said field structure, interrupter levers mounted on said field structure, pairs of contacts controlled respectively by said interrupter levers, said field structure having cut-away portions adjacent the free ends of said interrupter levers, a bumper connected to each interrupter lever and adapted to extend through its respective opening in the field structure, said rotor having cam surfaces formed therein adapted to cooperate respectively with the bumpers for actuating the interrupters, said cam surfaces being so disposed as to actuate the interrupter levers in alternation. and cause each pair of contacts to completely and independently control the discharge.

8. An ignition system including a magneto having a generating coil, a rotor, a field structure having pole pieces associated with said rotor, said generating coil being mounted on said field structure, interrupter levers mounted on said field structure, pairs of contacts controlled respectively by said interrupter levers, said rotor having cam surfaces adapted to actuate said interrupter levers, a casing for inclosing the rotor, interrupter levers, the contacts and the field structure, said casing having an opening adjacent the interrupter levers and the contacts, and means for closing said opening.

9. An ignition system including a magneto having a generating coil, a rotor, a field structure associated with said rotor and carrying said generating coil, spaced contacts, a bar electrically connecting and supporting said. contacts, means for insulat ing said bar and supporting the same on said field structure, an interrupter lever associated With each contact and having a contact adapted to engage therewith, a spring for eachinterrupter lever normally holding the contacts in engagement, said interrupter levers being grounded, and said supporting bar for the contacts being connected to the primary of said generating coil.

10. An ignition system including a magneto having a generating coil, a rotor, a field structure having pole pieces associated with the rotor, a generating coil carried by the field structure, a pair of fixed contacts insulated from and supported by the field structure, said contacts being connected to the primary Winding of the generating coil, an interrupter lever for each contact, a project ing lug carried by the field structure for each interrupter lever, a pivot bolt for supporting the interrupter lever on its respective lug, a spring for each interrupter lever for normally holding the contact carried thereby in engagement with the fixed contact, and means carried by the rotor for ac tuating said interrupter levers in alternation and so as to cause said contacts to completely and independently control the discharge.

In testimony whereof I hereunto allix my signature.

CHARLES THOHAS MASON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C.

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