US1376024A - Thews - Google Patents

Description

P. E. MATTHEWS.

AUTOMATIC PAWL THROW FOR MAGNETOS OR THE LIKE.

APPLICATION FILED JULY311919.

1,376,024, Patented Apr. 26,1921.

mvs vron RNEYS.

UNITED STATES PATENT oF Frcs.

PHILLIP E. MATTHEWS, OF PLAINFIELD, NEW JERSEY.

AUTOMATIC PAWL-THRDW FOR'MAGNETOS OR THE LIKE.

Application filed July 3,

To all whom it may concern:

Be it known that I, PHILLIP E. MAT- THEWS, a citizen of the United States, and residing in the city of Plainfield, countyof Union, and State of New Jersey, have 1nvented certain new and useful Improvements in Automatic Pawl-Throw for Magnetos or the like, of which the following is a full specification.

My invention is illustrated in the accompanying drawings and its particular novel features are pointed out in the annexed claims. j

My invention relates to an automatic pawl-throw mechanism for the purpose of actuating an impulse starting coupling for an ignition generator of the typeas is used in hydrocarbon engines for ignitlon purposes. The object of the impulse starting coupling in such generatorsls to impart a quick mechanical starting impulse to the generator when starting the engine so as to produce a strong spark to aid the ignltion at the start where the revolution number of the hydrocarbon engine, produced by the cranking operation, is low. Impulse starting couplings of this character are old 1n the art, such a coupling being shown for 111- stance in the U. S. Patent i -1,295,683 to H. Tiedemann dated February 25th, 1919. l

The particular novel features comprlslng my invention relate to the means by which the pawl, which temporarily retards the generator armature, is thrown into engagement. I have found it of great advantage to operate this pawl from the engine controll ng lever, in particular from the means by which the ignition is advanced and retarded and I propose to make this connection such that the pawl is thrown into engagement only when the ignition control lever of the engine is in retarded position. By this arrangement, I prevent the operator from accidentally throwing the pawl into engagement (such as might be possible if the pawl were controlled for'instance from the dash board by a separate lever) with the couphng device if the spark lever is still in advanced position. a

In the accompanying drawlngs, Figure 1 represents the end View of an ignition generator'showing the coupling side thereof, 7 Fig. 2 represents the plan view of the generator portion shown in Fig. 1, certain elements being shown partly in section,

Specification of Letters Patent.

1919. Serial No. 308,602.

Fig. 3 represents a modification of the lever connection and Fig. 4 shows in plan view a detail of the a spiral spring 20, one of whose ends is fas-,

tened to a pin 19 attached to disk 2 (see Patented Apr. 26, 1921.

Fig. 2) and whose other end is suitably fastened to the housing 3 (fastening not shown in the drawlngs). Of course, the yielding connection between the disk and the housing thus provided may also be effected in the manner shownin the aforementioned patent;

A slotted rim-4 is provided at the springhousing 3, with which a corresponding coupling member (not shown) may engage and from which the generator is driven. Thus, when spring housing 3 revolves, disk 2 by means of spring connection 20, is taken alon and the generator is rotated. On disk 2 (Fig. 1) are provided two notches 15 diametrically oppositely disposed which cooperate with a pawl 6 pivoted on the magneto housing at 7. This pawl as shown 1n the present illustration, is subject in its motion to the action of a toggle joint which cons sts of a pin 10'pivota1ly attached at its lower end 9 to a suitably shaped portion of pawl 6 and guided at its upper end in recessed lug 11. This lu is shown in plan view and in detail in Fig. 4:. A compression spring 12 is disposed on pin 10 and rests at its lower end against the eye 9 of the in and at its upper end against lug 11. hus the pawl will be held by the toggle joint either in a position in which it tends to engage one of the notches 15 of disk 2, or, if the center pin 8 of the tog le joint is thrown over to the right (indicated by dotted lines) pawl 6 will be held in a position in which it is disengaged from the periphery of disk 2 and thus prevented from engaging any of the notches 15. In that event, disk 2 can freely rotate in the direction of the arrow in Fig. 1. The holding of pawl 6 in either engaging or disengaging position may also be effected for instance by the means shown in the aforementioned pateng (compare therein the control of pawl 13 On spring housing 3 is provided a cam 5, and pawl 6 protrudes far enough laterally beyond the periphery of disk 2 (see Fig. 2) so that when cam 5 arrives at the top, it will disengage pawl 6 from the notch 15 in which it is located and thereby free disk 2. Thus, for instance, assumingthat pawl 6 has engaged a notch 15, and assum ng that by the turning over the engine spring casing 3 is turned one-quarter of a turn in the direction of the arrow, Fig. 1, then dlsk 2 being locked by pawl 6 cannot follow and spring 20 is thereby put under tension. If, after a quarter of a turn, cam, 5 arrives at the top, it disengages pawl 6 from notch 15 by which disk 2 is freed so that it now will quickly snap clockwise a quarter of a turn, due to the action of spring 20. This coupling arrangement is mounted on the generator shaft so that when this sudden release of disk 2 occurs, one of the pistons of the engine is at its firing stroke and this quick snappy turn of disk 2 causes the magneto to produce a strong hot spark which is suificient for starting.

The ignition generator on which my present invention has been illustrated in the drawings has means for advancing and retarding the ignition embodied in a form in which the field magnets of the generator are oscillated through a certain angle corresponding with the desired degree of advance and retardation. The oscillation of this field yoke 18 (Fig. 2) is controlled by the spark lever from the drivers seat (lever not shown in the drawings). Now, I propose to provide a lever 17 pivoted at 16 to the generator housing 1, whose arm 17 protrudes into the path of the field magnet 18, and whose arm 14 stands in the path of the center joint 8 of the toggle joint. Thus, when the spark is advanced and the field magnet 18 stands in the position shown in Fig. 2, arm 14.- of lever 17 is removed from the toggle joint so that the latter can be thrown out of engagement with disk 2 and into the position shown in dotted lines in Fig. 1. Now, in order to throw the toggle joint into the position shown in full lines in Fig. 1, when it is desired to start the engine, it becomes necessary for the operator to retard his spark lever which throws field magnet 18 to the right so that thereby arm 14: of lever 17 is thrown to the left (Fig. 2) which engages the toggle joint at its pivot 8 a-lnd throws pawl 6 into engagement with dis 1 2.

IVhile I have shown in Figs. 1 and 2 my novel idea applied to a particular form of generator, I do not wish to limit this invention to this form since it may be applied to any form of engine lever control in particular to any other form of spark advance and retard control for generators provided with the impulse starting coupling of the provided at such spark generators.

particular with the spark control lever near I the operators seat or which may be connected to the spark advance and retarding mechanism of any construction which ma be his lever 22, as shown in Fig. 3, is connected with a lever 17,, pivoted to the generator housingl at 16, such that the portion 14: of

this lever stands in the pathof themechanism which controls pawl 16, so that the operation is similar to the manner described with reference to Figs. 1 and 2.

The extent to which end 14 of lever 17 is thrown to the left in both modifications is such that when the spark control is retarded slowly, the toggle joint is brought close to the point at which it breaks to the left in F ig. 1. Thus by the slow retardation of the spark lever, the pawl is not thrown into engagement with disk 1, in order to avoid such engagement in case during the runnin of the engine the spark should be retarde for any reason. If, on the other hand, the

spark lever is retarded quickly, the momentum inparted to the toggle joint will throw it over the center and it will snap to the left and cause the engagement ofpawl 6 with disk 2.

A coil spring 23 is wound around 16, and

fastened to lever 17 at one end and to a lug on the casing of generator 1. The object of this spring is to press arm of'lever 17 against field magnet 18, so that when the spark lever is retarded and the mechanism is about to engage the pawl when starting the engine, the arm is in a positive position against the field magnet, insuring certainty that the field magnet will actuate the arm 17 and engage 14 with 6'.

1. In combination with an. ignition generator having field magnets capable of oscillating throu 'h a predetermined angle for advancing and retarding the ignition and having an impulse starting coupling comprising an operating shaft',a driven member fastened to said shaft, a driving member as.- sociated therewith, a resilient member forming a driving connection between the. driving and driven members, a pivoted pawl stop for said driven member and shaft, means operated by the driving member for engaging the pawl stop to remove it from engagement with the driven member, and

. yielding means for holding the pawl. in

2. In combination with an ignition generator having field magnets capable of oscillating through a predetermined angle for advancing and retarding the ignition and having an impulse starting coupling comprising an operating shaft, a driven member fastened to said shaft, a driving member associated therewith, a resilient member forming a driving connection between the drivin and driven members, a pivoted pawl stop %or said driven member and shaft, means operated by the driving member for engaging the pawl stop to remove it from engagement with the driven member, and a toggle joint for holding the pawl in or out of engagement with the driven member after having been so positioned, and a double arm lever pivoted on the generator housing and cooperating at one end with said magnets and at the other end with the center of said toggle joint for throwing said pawl into engagement with said driven member when the magnets are oscillated to retard the ignition.

PHILLIP E. MATTHEWS.

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