US2858819A

US2858819A - Speed control for outboard motors

Info

Publication number: US2858819A
Application number: US558876A
Authority: US
Inventors: Howard M Pollari
Original assignee: Mcculloch Corp
Current assignee: Mcculloch Corp
Priority date: 1956-01-13
Filing date: 1956-01-13
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04

Description

4, 1958 I' H. M. POLLARl I 2,85 1

' SPEED CONTROL FOR OUTBOARD MOTORS Filed Jan. 15, 1956 2 Sheets-Sheet 1 FIE. i

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lrraxuers 2 Sheets-Sheet 2 INVENTOR. flan/4R0 MPozuR/ wzwwg drroxksys H. M. POLLARI SPEED CONTROL FOR OUTBOARD MOTORS Nov. 4, 1958,

Filed Jan. 18, 1956 United States Patent SPEED CONTROL FOR OUTBOARD MOTORS Howard M. Pollari, St. Paul, Minn., assignor, by mesne assignments, to McCulloch Corporation, Los Angeles, Calif., a corporation of Wisconsin Application January 13, 1956, Serial No. 558,876

6 Claims. (Cl. 123-99) This invention relates generally to outboard motors and more particularly concerns a means for controlling the idle speed of such motors.

In conventional outboard motor construction the engine speed is controlled through advancement and retardation of the magneto spark, the engine throttle runing off of the magneto. The timing of magneto spark is determined by the setting of the magneto stator gear through the operation of a suitable manual control associated therewith. In heretofore known speed control mechanisms it has been impractical to provide for movement of the stator gear through operation of the speed control to an extreme spark retarding position to short out the magneto and kill the engine. A separate spark short-out switch has been used. This has been necessitated by the fact that where the speed control is utilized to short out the magneto it has been impossible for the operator to accurately retard the spark to an idle or low speed without frequent over-retardation to a point where the magneto shorts out. This problem, of course, arises wherever the operator of the boat propelled by the motor desires to reduce the speed to an idle or relatively low speed without actually shutting off the motor.

Furthermore in conventional engines which can be shut off only by operation of a separate switch after the speed control mechanism has been used to reduce the engine to a low speed, and where there is no load on the engine, a maverick spark has been known to occur in the magneto causing an undesirable increased speed of the flywheel. With the magneto short-out switch incorporated in the speed control mechanism the operator is a better position to prohibit this from occurring.

It is accordingly the primary object of the present invention to provide a new and improved speed control mechanism for outboard motors through which the magneto spark may be retarded to a desirable idle speed at which point resistance is imposed upon the manual control to warn the operator, but enabling the resistance to be overcome by continued operation of the control in a spark retarding direction to shut off the motor.

Another and more specific object of theinvention is to provide a speed regulating mechanism for outboard motors which includes a movable member on the magneto for varying the rate of spark and a manual control for operating said movable member and wherein there is provided suitable signal means sensually recognizable by the operator in his operation of the control in a speed reducing direction indicating that the movable member has been moved to such position as to provide the predetermined desirable idle speed for the motor, said 2,858,819 Patented Nov. 4, 1958 the mechanism, and said stop means being adjustable for variance of the speed at which it becomes effective.

With these objects of the invention in view the invention broadly comprises an outboard motor having a mag neto providing the ignition therefor, a movable member on the-magneto for advancing or retarding the magneto spark to increase or decrease the speed of the motor and movable to an extreme position in a spark retarding direction to short out the magneto and kill the motor, a manual control mechanism for operating the movable member, and a stop device on the motor adapted to be contacted by said control mechanism when the movable member has been moved in a spark retarding direction to such point as to provide a desirable idle speed for the motor, said stop device being supportedin its contact position by a resilient means so as to yield when increased pressure is applied to the control mechanism in a spark retarding direction allowing movement of the movable member to said extreme position. The invention also provides for adjustably positioning the stop device in its yieldable condition for initial contact thereof by the control mechanism at different idle speeds.

The above mentioned and still additional objects of the invention will be brought to light during the course of the following specification, reference being made to the accompanying drawings, in which Fig. 1 is a perspective view of a section of the engine of an outboard motor with the engine housing removed and showing the improved speed control mechanism and stop means in motor idling position.

Fig. 2 is a plan view of the manually operative speed control handle for the motor and the stop means in motor idling position with the stop engageable portion of the speed control mechanism shown in advanced speed position in broken lines.

Fig. 3 is a longitudinal vertical section through the stop means and its supporting bracket taken along the line 33 of Fig. 2, with the stop in motor idling position and showing the stop plunger in a yielding position in broken lines.

Fig. 4 is a transverse vertical section through the stop supporting bracket taken on line 44.

Referring now more particularly to the drawings reference numerals will be used to denote like parts and structural features in the different views. A section of the powerhead or engine of an outboard motor with the usual cover therefor removed is shown in perspective in Fig. 1. The engine includes the cylinder block 10, carburetor 11 and the magneto generally at 12. The engine is mounted on a bracket 13 which in turn is mounted on a conventional boat mounted bracket (not shown) for turning on a vertical axis. A conventional handle 14 for turning the motor extends forwardly from the bracket 13.

The magneto 12 which provides ignition for the engine includes a stator gear 15 which is movable about the magneto axis to advance or retard the spark. Gear 15 carries a cam member 16 adapted to operate the throttle in synchronism with the spark through linkage to carburetor 11 to be later described. An integral bracket 17 on the engine enclosure 10 has a bearing portion 18 which journals a stator pinion assembly 19 for oscillating movement on a vertical axis. The assembly 19 has an arcuate rack Ztl having teeth which mesh with teeth on the circumferential edge of stator gear 15 whereby as the pinion 19, as viewed in Fig. l, is swung to the right or left about its turning axis at 21 the stator gear will respectively be moved in a spark advancing or retarding direction.

Assembly 19 has a portion 22 which projects downwardly beyond the bearing 18 to be locked in a socket 23 mounted at the upper end of elongated upright coupling member 24. The lower end of coupling member 24 is anchored in a gear member 25 which is journaled for rotation in the mounting bracket 13, the longitudinal axis of member 24 being in alignment with the turning axis of the gear member. Member 25 has a section of mitor gearing 26 the teeth of which extend radially outward and downward along the front side of the member.

The steering handle 14 and its connection with the gear member 25 are best shown in Fig. 2. The handle has an outer casing 27, the forward end of which carries a rotatable grip 28. A shaft means (not shown) is connected to the grip 28 and extends rearwardly through the casing 27 carrying a bevel gear 36 at its rear end which gear is in meshing engagement with the toothed section 26 of the member 25. It will be noted that the handle 14 is hinged to the bracket 13 at 31 for upward folding movement, At this point the aforementioned shaft means is provided with a suitable universal joint such as a pair of enmeshed miter gears.

It will now be understood that the position of the stator gear and accordingly the rate of spark of the magneto is controlled manually by operation of the twist grip 28. As the grip is rotated the bevel gear 30 at the rear end of the grip connected shaft means will turn the gear member 25 and coupling 24 about their common vertical axis. The stator pinion assembly 19 will in turn be swung about the pivot 21 with rack moving the member 15, with which it meshes, in the desired direction.

Gear member has been provided with a laterally projecting lever extension 33 which swings fore or aft about the turning axis of the gear member during the spark advancing or retarding operation. This lever is here shown as being provided with an attachment nipple 34 for connection with remote control devices for controlling the motor spark, such nipple however forming no part of the present invention.

The mounting of the motor on the bracket 13 in addition to a seat connection at 35 includes a spring assembly 36 at each side. These assemblies aid in reducing vibration and facilitate silent operation of the motor. Each assembly 36 comprises a coil spring 37 held under compression between a depending bracket 38 mounted on the side of block 10 and an upright spring seat 39 formed on mounting bracket 13 and spaced rearwardly from the spring bracket 38. Seat 39 is provided with a small cylindrical boss 40 which is encircled by the rear end of spring 37 to hold the spring in position.

Attention is directed to Figs. 2, 3 and 4 for clearer understanding of the structure to be now described. A

stop plunger retainer sleeve 41, preferably of cylindrical exterior design, is press fitted in an aperture 42 in the bracket 38 to extend in a fore and aft direction to the rear of the lever arm 33. Sleeve 41 has an annular flange 43 at its forward end to engage against the front face of bracket 38. The sleeve 41 has a relatively deep cylindrical recess 44 in its forward end and a hexagonal recess 45 in its rear end, said recesses being connected through the central portion 46 by means of a bolt passage 47. It will be noted that sleeve 41 extends rearwardly beyond bracket 38 within the coil of spring 37.

A threaded stud bolt 48 having a hexagonal head 49 is inserted forwardly through sleeve 38, the head 49 fitting within the hexagonal recess 45 to be locked against rotation therein. The bolt 48, however, is freely slidable longitudinally within the sleeve. A stop head is threaded on the forward end of bolt 48 and coil spring 51 encircles the bolt and is held under compression between the sleeve portion 47 and the head 50.

"Spring 51 acting between the head 50 and retainer sleeve 41 serves to yieldably hold the stop assembly, comprised of bolt 48 and head 5%, in its forwardmost position with head 49 seated in the socket 45. Plunger head 50 lies-immediately to the rear of the swingable lever arm 33. The threaded connection between the plunger head 50 and bolt 48 allows longitudinal adjustment of the head between bracket 38 and the lever arm 33.

As heretofore brought out, as the grip 28 is rotated to advance or retard the magneto spark the gear member 25 will be rotated to cause a fore and aft swinging of arm 33. When the grip is turned in a spark retarding direction arm 33 will swing rearwardly toward the head 5% of the stop assembly. In operation head 50 is adjusted on the bolt 48 so as to be so positioned that initial contact between arm 33 and head 59, when arm 33 is swung rearwardly, is made when stator link 15 has been moved to a position for a desirable idle speed of the motor.

During spark retarding operation of the control 28 as arm 33 engages the head 50 the head resists further rearward movement of the arm. This resistance can be readily recognized by the operator as increased turning pressure must be exerted upon the grip to further retard the spark. Accordingly, the operator can sense immediately when the safe idle speed of the motor has been reached. To turn off the motor the operator merely applies slightly additional turning pressure to the grip and the stop and its spring 51 will yield under pressure from the arm 33 allowing

members

24 and 19 to move the member 15 to an extreme spark retarding position where the magneto will short out to stop the engine. The sliding axis of the plunger bolt 48 is on a plane with the path of movement of arm 33 insuring a positive yielding action of the stop plunger. The depressed position of the stop device is shown in broken lines in Fig. 3. When the spark is again advanced and arm 33 is swung forwardly the head 50 will, of course, again return under action of spring 51 to a position to be contacted at the idle speed.

It is, of course, important that spring 51 be only of such a strength as to render turning of handle 28 in a spark retarding direction somewhat more difficult after the arm 33v has made contact with head 50 so as to indieate to the operator that the preselected idle speed has been reached.

Operation of the carburetor 11 off of the magneto 12 is conventional and will be readily understood. A rocker member 53 is journaled in a bearing 54 mounted on the engine housing. Rocker 53 has angularly disposed

radial arms

55 and 56, the former of which is suitably biased against the peripheral edge of cam 16 while the latter is connected as by link 57 to throttle shaft lever 58. As stator gear 15 is moved to the right, as viewed in Fig. 1, member 16 which moves therewith cams rocker 53 forwardly about its turning axis depressing arm 56 and lever 58 to open the throttle shutter. Conversely when link 15 is moved to the left or in a spark retarding direction the cam allows reverse movement of the rocker to raise the lever 58 in a throttle closing direction to reduce the engine speed.

While I have herein shown and described the yieldable idle stop device as being placed to engage the remote control arm 33 it will be understood that the stop would serve with equal effectiveness if placed to cooperate with other movable parts in the speed control mechanism including the hand grip 28, the throttle control arm 58 and all movable parts in the linkage therebetween. An example of such a modification of the invention would be disposition of the stop means in the magneto area to be contacted by the member 19 or link 15 itself when the predetermined idle speed has een reached. The important concept is that resistance be met during speed reducing operation of the motor at the speed where the motor will continue to function at a safe idling speed and that such resistance be yieldable under increased speed reducing pressure on the manual control.

It is understood that suitable modifications may be made in the structure as disclosed, provided such modifications come within the spirit and scope of the appended claims. Having now therefore fully illustrated and described my invention, what I claim to be new and desire to protect by Letters Patent is:

1. In an outboard motor, an engine, a manual speed control mechanism on the engine having a part which is movable between extreme positions of and advanced engine speed and an engine killing position, a stop means mounted on the engine engageable by the part intermediate its extreme positions when moved toward the engine killing position, and said stop means being spring held to yield under continued movement of the part toward the engine killing position.

2. An outboard motor having an internal combustion engine and a magneto for providing the electric spark for ignition to such engine, a movable manual control having connection with the magneto for advancing or retarding the magneto spark between advanced speed and magneto short-out positions and there being an intermediate position for a desirable idle speed of the engine, the connection between the control and magneto including a stop member resisting movement of the control in a spark retarding direction beyond said intermediate position, said stop member being supported in its resisting position by a resilient means so as to yield under forced movement of the control toward the magneto short-out position.

3. In an outboard motor, an engine including a magneto for providing ignition to the engine, a movable member on the magneto for advancing or retarding the spark and movable to an extreme position in a spark retarding direction where the magneto will short out to kill the engine, a manual control having connection with the movable member for operating said member, said connection including a part adapted to pass along a set path as the movable member is moved in a spark retarding direction, a stop member on the engine intersecting said path to contact said part as the control is operated to retard the spark and before the movable member reaches said extreme position, and spring means supporting the stop member on the engine for yielding movement of said member as said part continues to pass along its path after contact to bring the movable member to said extreme position.

4. In an outboard motor, an engine, a manually operated speed control mechanism on the engine which is movable between extremes of an advanced engine speed position and an engine shut-off position and various positions therebetween for increasing or decreasing the engine speed, said mechanism including an element which moves along a set path as mechanism is operated between positions, a stop means for resisting movement of the mechanism in a speed decreasing direction beyond a certain speed, said stop means comprising a housing mounted on the engine, a plunger slidably disposed within said housing and projecting into said set path to contact and resist further movement of the element along the path when said certain speed is reached, and

ing the same, said connection including a stop member engageable when the movable member is at an intermediate position to resist further movement thereof in a spark retarding direction, the stop member being yieldably mounted on the motor to give way when increased manual pressure is applied to the control in movement of the movable member in a spark retarding direction, and adjustment means on the stop member for selective positioning thereof enabling it to be initially engaged at various intermediate positions of the movable member.

6. An outboard motor having an engine, a magneto mounted on the engine for providing ignition to the engine, a movable stator gear on the magneto for adjusting the spark to increase or decrease the speed of the engine, a rotatable control handle on the engine, a shaft element rotatably journaled on the engine and having gear means at one end meshing with the control handle and gear means at its other end meshing with the stator gear whereby the spark may be adjusted through operation of the control handle, and means for imposing resistance upon the control handle when the engine has reached a desirable idle speed during speed decreasing operation of the handle, said means comprising an arm on the shaft element adapted to rotate therewith, a bracket rigidly mounted on the engine and a stop member mounted on the bracket adjacent said arm in such position as to be engaged thereby upon reaching said idle speed when the control is operated in a speed decreasing direction, the stop member mounting including a coil spring held under compression between the bracket and stop member to yieldably hold the stop member in position for engagement by the arm.

References Cited in the file of this patent UNITED STATES PATENTS