US2791207A

US2791207A - Choke and grounding switch control for engine with magneto ignition

Info

Publication number: US2791207A
Application number: US492943A
Authority: US
Inventors: Joseph G Rayniak
Original assignee: Outboard Marine Corp
Current assignee: Outboard Marine Corp
Priority date: 1955-03-08
Filing date: 1955-03-08
Publication date: 1957-05-07
Anticipated expiration: 1974-05-07

Description

May 7, 1957 I J. G. RAYNIAK 2,791,207

CHOKE AND GROUNDING SWITCH CONTROL FOR ENGINE WITH MAGNETO IGNITION Filed March 8, 1955 2 SheetsSheet 1 INVENTOR. ose-PH 6. E4 Y/wnx A Troews j May 7, 1957 J. G. RAYNIAK CHOKE AND GROUNDING SWITCH CONTROL FOR ENGINE WITH MAGNETO IGNITION 2 Sheets-Sheet 2 Filed March 8, 1955 2% JNVENTbR.

. JOJEPH G. Fnv/v/AK 4/ [Lip AM, AM w M1 ATTOEI/E v5 CHOKE. AND GROUNDING SWITCH CONTROL FOR ENGINE WITH MAGNETO IGNITION Joseph G. Rayniak, Waukegan, Ill., assignor to Outboard Marine Corporation, a corporation of Delaware Application March 8, 1955, Serial No. 492,943

14 Claims. (Cl. 12399) This invention relates to a combination choke and grounding switch control for an engine with magneto ignition. It is desirable to preclude the use of a carburetor choke during the cranking of an engine which is incapable of starting. It is also desirable to make it impossible to stop the engine by shorting its magneto at a time when the choke valve is closed.

To accomplish these results and at the same time to provide a simple and efliective means of controlling the choke and the grounding switch with a single control member, I have provided a handle with a shank having some of the characteristics of a key and projecting through aligned slots in the shroud of an internal combustion engine. The handle shank has portions of in creased width which, like the wards of a key, prevent rotation of the handle when it is in one position of axial adjustment and permit rotation when it is in another position of axial adjustment, one of the slots through which the handle is reciprocable, being in the nature of a keyhole slot with margins which cooperate with the wards of the handle shank to control the direction of potential movement of the handle.

In the particular embodiment, the handle is axially reciprocable to control the opening and closing movement of the choke valve, and rotatable to control the opening and closing movement of the grounding switch. The connection of the handle to the choke valve is conveniently and simply effected by simply providing an aperture in the handle through which a rocker arm on the choke shaft loosely projects.

The grounding switch is of a simple construction in which a ground wire of spring material provides a contact deflected into circuit closing position by engagement with one of the wards of the control handle.

One of the advantages of the specific construction disclosed lies in the fact that the grounding switch will automatically remain closed until manually released, the handle being biased by the contact spring in both directions from an intermediate position. The spring first opposes movement of the handle toward support closing position and, when dead center is passed, urges the handle toward its ultimate position in a circuit closing direction and opposes movement of the handle from that position.

While the invention has utility beyond its specific application herein disclosed, it may be noted that in commercial practice the invention is used to control the choke and the grounding circuit of a two cycle engine which operates a rotary power lawn mower and has its engine equipped with magneto ignition.

In the drawings:

Fig. 1 is a plan view of an engine having a control device embodying the present invention.

Fig. 2 is a view of the invention in side elevation with a portion of its shroud and adjacent parts broken away to expose the control device.

Fig. 3 is a detailed view on an enlarged scale and partially diagrammatic, to show in side elevation the control atent device and the parts controlled thereby, portions of the engine shroud being illustrated in section.

Fig. 4 is a view taken in section on the line 4--4 of Fig. 3.

Fig. 5 is a view similar to Fig. 3 showing the control device as it appears when operated to a position in which the choke valve is open and the ignition switch is closed.

Fig. 6 is a view taken in section 011 the line 6'6 of Fig. 5.

Fig. 7 is a fragmentary detailed view taken in the plane indicated at 77 in Fig. 8.

Fig. 8 is a detailed view taken in section on the line 8--3 of Fig. 4.

Fig. 9 is a detailed view in perspective, showing in relatively separated positions certain component parts of the switch.

Fig. 10 is a diagrammatic view, including a fragmentary section through a flywheel magneto and showing the connection of the grounding switch illustrated in Figs. 4 and 6 to 9.

In order to exemplify the invention, it has been shown applied to an internal combustion engine having a cylinder 12, spark plug 13, piston 14, crank shaft 15, flywheel 16, fuel tank 17, and starting handle 18. The fuel tank is incorporated in a shroud 20 which encloses the flywheel and directs cooling air from the flywheel blades 21 over the cylinder fins 22. The shroud includes a top wall 23 and a bottom wall 24 having registering openings at 25 and 26 for the shank portion 27 of a manually operable control 28 for choke valve 29 and magneto grounding switch 30. As shown diagrammatically in Fig. 10, the flywheel 16 includes a magnet 31 which rotates past an armature 32 upon which there is wound a transformer 33. The primary of this transformer is controlled by a breaker switch 34 actuated by cam 35 on the crank shaft 15. The breaker switch is by-passed by a ground line 36 controlled by the grounding switch 30. The secondary of the transformer 33 is connected in series with the spark plug 13 so that, unless the grounding switch 30 is closed, the magneto will supply current to the spark plug at all times during flywheel rotation.

The choke valve 29 is mounted on a rock shaft 38 which spans the air inlet 39 to any desired mixing valve or carburetor 40 through which carbureted air is admitted, subject to regulation by throttle valve 41, to the engine crank case 42. As is well known, the closing of the choke valve 29 limits the admission of air and thereby subjects the fuel line to increased engine vacuum to increase the mixture admitted to the engine, thereby facilitating cold starting.

The control handle 28 is fastened to the upper end of shank 27. The shank is provided near its lower end with a relatively large opening at 44 through which projects loosely the free end of rocker arm 45 mounted on the choke shaft 38. If the control knob 28 and its shank 27 are drawn upwardly to the position of Fig. 3, the arm 45 will oscillate rock shaft 38 to move the choke valve 29 to the position shown in Fig. 3, substantially reducing the available capacity of the air inlet pipe 39 of the carburetor. Fig. 2 shows the control member pushed down to its extreme limit of movement in the opposite direction, whereby the choke valve 29 is in its full open position. Choke valve manipulation is controlled solely by the longitudinal movement of the control element 28 and its shank 27.

Oscillation of control member 28 between the run and the off positions indicated in Fig. 1 is used as a means of opening and closing the grounding switch 30. In order to make it clear how this is done, the extremely simple construction adopted for the switch will first be explained: the wire lead 36 from the primary of transaroma? former 33 is provided at its end with a reverscly bent hook portion 47 laid into the groove 48 of the dielectric element 49 and there clamped by placing the dielectric plate 50 on top of it. The bottom wall 24 of the engine shroud is provided with a boss at 52 abutted by the

square ends

53, 54 of the

dielectric plates

49 and 50, as clearly appears in Fig. 8. The plates are held assembled to the bottom wall 24 by means of screw 51 and

dowel pegs

55 and 56. The former is received into an opening 57 of plate 50. Peg 56 is received into a slot 58 in plate 49. In the assembled position of the parts, the portion 60 of the hook 47 is exposed, as clearly shown in Figs. 4 and 6.

The movable contactor comprises a piece of spring wire which encircles the boss 66 formed on the shroud wall 24, as best shown in Figs. 7 and 8. The free end portion 67 of the spring 65 abuts the integral lug 56 to keep the spring from oscillating bodily around boss 66. The portion 68 of the spring wire 65 extends past the side of the shank portion 27 of the operating member in the manner shown in Fig. 4, when the operating member is in the angular position in which it is illustrated in Figs. 2 to 4. At 69, the spring is bent upon itself and carried back around dowel 55, beyond which its free end portion is turned downwardly as best shown in Fig. 3 to the plane of the exposed portion 60 of the ground wire lead 36. In the event that the control shank 27 is rotated from the position of Fig. 4 to the position of Fig. 6, the portion 69 of the spring Wire will be engaged and deflected by the margin of the shank to oscil- 0 late the contact terminal 70 of the wire into engagement with the exposed portion 60 of ground wire 36, thereby grounding the wire 36 and, through it, the primary of the magneto to short the breaker.

As will be evident upon comparison of Fig. 4 and Fig. 6, the initial movement of the control shank 27 will be opposed by the resilient bias of the Spring 65. As the shank overcomes this bias, the free end contact 70 of the spring will almost immediately engage the wire 60 to close the grounding circuit. Continued movement of the control member to its otf position shown in Fig. 6 will cause the edge of the shank 27 to move past dead center so that, in the Fig. 6 position of the parts, the bias of the spring 65 is exerted on the control shank in a direction to maintain the control in its said off position. The shorting switches conventionally provided for stopping two cycle engines have to be held manually in their shorting positions until the engine stops running. An advantage in the present device lies in the fact that despite its simplicity and low cost, it will stay in the circuit closing position of Fig. 6 until manually moved out of that position.

The control has one lug or ward at 72 which engages beneath the top wall 23 of the motor shroud or housing to preclude upward movement of the control beyond the position shown in Fig. 3. Its other extreme of movement is shown in Fig. 5 and is defined by engagement of the handle 23 with top wall 23 of the shroud.

The lower end of the shank portion 27 of the control element is widened to provide an elongated ward at 75 terminating at its upper end in a shoulder 76. The keyhole slot 26 in the lower wall 24 of the shroud communicates, as shown in Fig. 7, with a sector shaped re ccss 78 which receives the ward 75 to permit a limited rotation of the control member between its run and its off positions when the narrow portion of shank 27 is lowered to the position of Fig. 5, the circular portion 79 of. keyhole slot 26 being of a diameter to permit the narrow portion of the shank to rotate therein, thus rotating the shouldered portion 76 of ward 75 to move into the recess 78. The oscillation of the control member from side to side between the positions of Fig. 3 and Fig. 5 is readily accommodated so far as the arm 45 is concerned by the loose fit of this arm in the opening 44 at the lower end of the control shank.

With the control in the off position of Fig. 5, it is impossible to choke the engine by reason of engagement of shoulder 76 beneath that portion of the shroud wall 24 which overlies the recess 78. In order that the control member may be moved longitudinally to close the choke valve 29, it is necessary that the control member first be oscillated clockwise from the position of Figs. 5 and 6 to the position of Figs. 3 and 4 to register the warded portion of shank 27 with the elongated slot of the keyhole opening 26. Only then can the choke valve be closed, the grounding switch then being open so that the engine will start.

A converse interlock is provided to prevent the grounding switch from being closed while the engine is choked.

This interlock is eifective by reason of the fact that the raising of the control to close the choke valve elevates the warded portion of the control into the elongated portion of the keyhole opening, as shown in Fig. 3 and Fig. 4, in which position the control is incapable of rotation and hence can not be used to ground the engine.

I claim:

1. A combination choke and grounding switch control comprising the combination with a choke valve and a grounding switch, of a single control element, a connection actuated by movement of the control element in one direction for moving the valve between open and closed position, a connection actuated by movement of the control element in a different direction for moving the switch between open and closed positions, together with means for rendering the connection to the switch inoperative to actuate the switch when the valve is closed.

2. A combination choke and grounding switch control comprising the combination with a choke valve and a grounding switch, of a single control element, a connection actuated by movement of the control element in one direction for moving the valve between open and closed position, a connection actuated by movement of the control element in a different direction for moving the switch between open and closed positions, together with means for rendering the connection to the valve inoperative to actuate the valve when the switch is closed.

3. In a device of the character described, the combination with a valve and a switch respectively movable between open and closed positions, of a control common to the valve and the switch and having a connection actuated by movement of the control element in one direction for operating the valve and a connection actuated by movement of the control element in a ditferent direction for operating the switch, and means for restricting the operation of one of said connections dependent upon the position of the other.

4. In a device of the character described, the combination with a valve and a switch respectively movable between open and closed positions, of a control common to the valve and the switch and having actuating connections for operating the valve and switch respectively between the said positions and means for restricting the operation of one of said connections dependent upon the position of the other, said control being rotatable and axially movable, one of said connections being operated by rotation of the control and the other of said connections being operated by its axial movement.

5. The device of claim 4 in further combination with a member having a keyhole slot through which the control member is movable, said control member and slot having complementary portions accommodating rotation of the control member in one position of axial adjustment thereof and other complementary portions precluding rotation of the control member in another position of axial adjustment thereof.

6. The device of claim 4 in further combination with an apertured support through which the control member extends, the control member and the support having complementary portions permitting free axial movement of the control member through the support in one position of rotation of the control member and other portions interlockingly engageable to preclude axial movement of the control member through the support in another position of rotation of the control member.

7. In a device of the character described, the combination with a valve and a switch respectively movable between open and closed positions, of a control common to the valve and the switch and having connections operating with the valve and the switch in their movement between said positions, said control having means mounting it for oscillation and for reciprocation, one of said connections being operable in the oscillation of the control and the other in the reciprocation thereof, said last connection comprising a rock shaft having an arm for which the control has an opening through which the arm loosely extends.

8. In a device of the character described, the combination with a valve and a switch respectively movable betweeen open and closed positions, of a control common to the valve and the switch and having connections operating with the valve and the switch in their movement between said positions, said control having means mounting it for oscillation and for reciprocation, one of said connections being operable in the oscillation of the control and the other in the reciprocation thereof, said first connection comprising a spring having its bias exerted against the control and deflected in the movement of the control from each of its extreme positions toward the other.

9. In a device of the character described, the combination with a valve and a switch respectively movable between open and closed positions, of a control common to the valve and the switch and having connections operating with the valve and the switch in their movement between said positions, said control having means mounting it for oscillation and for reciprocation, one of said connections being operable in the oscillation of the control and the other in the reciprocation thereof, said mounting means comprising a keyhole slot through which the control is reciprocable in one position of angular adjustment, said control having a ward extending longitudinally thereof and interlocking with said mounting means to preclude oscillation of said control in one position of longitudinal adjustment thereof and to preclude longitudinal movement of said control in one position of oscillation thereof.

10. In a device of the character described, the combination with a valve and a switch respectively movable between open and closed positions, of a control common to the valve and the switch and having connections operating with the valve and the switch in their movement between said positions, said control having means mounting it for oscillation and for reciprocation, one of said connections being operable in the oscillation of the control and the other in the reciprocation thereof, said switch 6 comprising a relatively fixed contact and a contact spring positioned adjacent the control, said control having a laterally extending portion engageable with said spring to deflect the spring in the oscillation of the control, said spring having a contact portion engageable with the fixed contact upon the occurrence of such deflection.

11. In a device of the character described, a control element having a laterally projecting ward portion, a mounting plate having a keyhole slot with which such ward portion interacts, dielectric clamp plates connected with the mounting plate, a terminal lead clamped between the clamp plates and having a terminal contact portion and a spring for which one of said clamp plates provides an anchorage, said spring having a portion projecting from its said anchorage past the keyhole slot in a position to be engaged by the ward portion of said control, said spring having a contact portion engagcable upon dellection of the spring with the contact portion of said lead.

12. In an internal combustion engine having mounting means and provided with a carburetor having a choke valve and with a magneto, the combination with the said mounting means and choke valve of a magneto grounding switch, a control member having a shank portion mounted for reciprocation and oscillation in said mounting means, said shank portion being provided with a handle at one side of said mounting means and being provided at the other side of the mounting means with an aperture, a rock shaft connected with the choke valve, and having an arm extending loosely through said aperture for the oscillation of the rock shaft in the reciprocation of said shank portion, the aperture having sufiicient clearance to permit oscillation of the shank portion respecting said arm, and means effective upon the oscillation of the shank portion for opening and closing the magneto grounding switch.

13. The device of claim 12 in which the said shank portion has ward means for which said mounting means has an interlocking part engaged with the ward means to restrain oscillation of the shank portion in one position of shank means reciprocation, and engaged with the ward means to prevent reciprocation of the shank portion in one position of shank oscillation.

14. The device of claim 13 in which said switch comprises a movable contact element engaged by said ward means to receive motion therefrom in a switch closing direction in the oscillation of the shank portion of the control and having bias toward switch opening position to open the switch upon a reverse oscillation of said shank portion.

Harder et al. Apr. 21, 1942 Boling May 19, 1942