US2831352A - Combustion engine starting assemblies - Google Patents

Description

April 22, 1958 w. T. ELLIOTT ET AL 2,831,352

coMBusTIoN ENGINE sTARTxNG AssEMBLIEs 2 Sheets-Sheet 1 Filed Dec. 3, 1956 z. WMZ MIL@ ff. l WZ M w 4 April 22, 1958 w. T. ELLIOTT ET AL 2,831,352

COMBUSTION ENGINE STARTING ASSEMBLIES Filed DBC. 3, 1956 2 Sheets-Sheet 2 2,831,352 CMBUSTIN ENGENE STARTING ASSEMBLIES Application :December 3, 1956, Serial No. 625,840

13 Claims. (Cl. 'M

This invention relates to internal-combustion engine starting assemblies, and more particularly to devices for cranking such engines by means of an electric motor.

In starting internal-combustion engines, especially those used for lawn mowers, auxiliary lighting equipment, marine engines and similar applications, it is customary to utilize hand-driven devices such as rope starters, or powerdriven means such as an electric motor which cranks the engine through an overrunning clutch. Besides the expense in constructing and maintaining starting devices which include over-running clutches, such arrangements have the disadvantage that considerable frictional losses occur, since the electric motor is never completely isolated from the running engine.

It is an object of the present invention to provide a novel and improved starting mechanism for internal-combustion engines which is extremely simple and durable, and which completely isolates the electric motor from the engine after the latter has been started, thus reducing frictional losses and increasing engine eiiciency.

it is another object to provide an improved starting mechanism of this type, which is compact and occupies a minimum of space, is completely accessible to the operator, and in which energization of the motor and clutching of the motor to the engine crankshaft may be easily controlled by a single hand motion.

Other objects, features, and advantages of the present invention will become apparent from the subsequent description, taken in conjunction with the accompanying drawings.

`In the drawings:

Figure l is an elevational View of the improved starting assembly taken in cross section along thebroken line 1 1 of Figure 2 and showing the construction of the cone clutch, the mounting posts and the housing;

Figure 2 is .a top plan View of the starting assembly showing the relative location of the electric motor and the clutch housing;

Figure 3 is a fragmentary cross-sectional view in elevation taken along the line 3 3 of Figure 2 and showing the pinion outboard bearing support;

Figure 4 is a cross-sectional View in elevation taken along the line 4 4 of Figure 2, parts being broken away, and showing the cross-sectional configuration of the housing; and

' Figure 5 is an end elevational view taken in the direction of the arrow of Figure 2 `and showing the location of the receptacle for the power supply.

In general terms, the invention comprises a mounting ring adapted to be secured to the exterior of an internalcombustion engine concentric with the crankshaft, and a somewhat dome-shaped housing mounted outwardly of the ring for axial movement toward and away from the engine. The housing supports an electric motor the axis of which extends transversely with respect to the engine crankshaft axis, and reduction gearing is mounted within States Patent O connected to the driving elementv of a cone-type friction clutch. The driven element of the clutch is secured to the engine crankshaft, so that when the starter housing is depressed by hand pressure, the clutch. driving element will be brought into engagement with the driven element. A control switch for the electric motor is mounted beneath the housing dome, the arrangement being such that pressure of the operators palm will cause .energization of the motor immediately before the clutch is engaged. After the engine has started, the operator may release his hand from the housing, simultaneously de-energizing the motor and disengaging the friction clutch. The engine will thus continue to operate without interference or frictional losses incurred by the starting assembly which is mounted thereon. l

Referring more particularly to the drawings, a portion of an internal-combustion engine generally indicated at 11 is shown in Figure 1, this engine having a crankshaft 12 supported on a vertical axis. It will be understood however that the invention is equally applicable to internalcombustion engines having crankshafts arranged other than as shown in Figure 1. In the present instance, engine 11 is shown as having a circular opening 13 at its upper end for entry of air used in combustion. Secured to the upper surface of engine 11 and surrounding opening 13 is a mounting ring 14, this ring having three peripherally spaced guide posts 15 secured thereto. Posts 15 extend upwardly from bosses 16 formed on mounting ring 14 and serve to guidea starter housing generally indicated at 17 mounted above engine 11. In particular, housing 17 is substantially dome-shaped,` having .a flange portion 18 which carries three bushings 19 embedded therein,

these bushings being of an anti-friction material such as' a plastic and being adapted to receive posts 15. A coil compression spring 21 surrounds each pin and is disposed between the upper surface of mounting ring 14 .and the undersurface of housing flange 18, these springs urging housing 17 upwardly with respect to engine 11. The upper position of housing 17 is dened by three stop pins 22 mounted in the upper end of guide pins .15, these stop pins having elongated manually rotatable heads 23 above bushings 19. The bushings are provided with slots 24, best seen in Figure 2, and stop pins 22 are rotatable between a locking position shown in Figure 2 .and a releasing position 90 from the locking position. When pins 22 are in their releasing position, heads 23 thereof will be aligned with slots 24 in bushings 19, thus permitting housing 17 and the parts mounted `thereon to be removed upwardly. The upper ends of springs 21 preferably `tit snugly around the lower ends of bushings 19, so that the springs will stay with the housing assembly when removed. A compression spring 25 may be provided Within a counterbore at the upper end of each guide pin 15 for maintaining frictional pressure on each stop pin 22 so as to hold it in its adjusted position.

Housing 17 is flattened on one side thereof, this side being provided with an open portion 26, and an electric motor 27 is secured to portion 26 of the housing, the axis` of motor shaft 28 being horizontal. It should be noted that although motor 27 extends from one side of housing 17, guide posts 15 are so positioned as to maintain the housing in proper position for its vertical movement. The inner end of motor 27 is secured by a plurality of bolts 29 to a vertical mounting wall 31 formed as part of housing 17, this wall having a central clearance aperture 32 for j shaft 28. The inner endrof shaft 2S carries a pinion 33,

and an outboard bearing 34 is provided for shaft 28 adjacent pinion 33. The construction of bearing 34 is best seen in Figure 3, the bearing being fabricated of an anti` the housing dome, the output end of this gearing being friction material such as a plastic and being mounted between shaft 2S and a downwardly projecting boss 35 on the interior of housing 17. Bearing 34 engages the upper half of shaft 2S since, as will be later noted, the operational forces on this shaft have an upward component.

vA central boss 36 projects downwardly within housing 17 and carries a shaft 37 pressed therein and extending downwardly therefrom. Shaft 37 is of tubular config` uration, and a combined gear and driving clutch member 3S is rotatably mounted at the lower end of this shaft by'means of a bearing 39 the lower end of which is supported by a spring lock ring 41 on shaft 37. As illustrated in Figure l, this combined gear and driving clutch memberis of integral construction with its relative dimensions being such as to permit fabrication by die casting or similar techniques. An annular thrust bearing 42 is mounted on and surrounds an intermediate portion of shaft 37 and is disposed between the lower end of housing boss 36 and the upper end of member 3S. Gear teeth 43 are formed on the upper surface of member 38, these teeth meshing with the teeth on pinion 33. Although various forms of gear and pinion teeth may be used within the principles of the invention, a suitable form of such gears is a gear arrangement of the type disclosed in Patent Nos. 2,696,125 and 2,731,886. As described in the aforesaid patents, this is a skew axis Worm gearing arrangement involving a face-type worm gear and conical pinion, which has been found to have comparatively high load carrying ability, co-ntribute to a reduction or elimination of backlash, and facilitate wear adjustment. Member 38 has an annular portion projecting downwardly from the upper portion on which teeth 43 are formed, and the inner surface of this annular portion is flared outwardly and downwardly and is provided with a frictional clutch facing 4.4.

Disposed partially within the confines of the annular portion of driving clutch member 38 is a driven clutch member 45 of annular shape secured to the upper end of crankshaft 12. Member 4S carries an annular clutch surface 45 which is flared outwardly and downwardly at the same angle as the flared surface of driving clutch member 3S. The arrangement is such that when housing 17 and the parts mounted thereon are in their upper position, the operative surfaces of the driving and driven clutch members will be siightly spaced from each other, as shown in Figure l. When housing 17 is moved downwardly, driving clutch member 38 will approach the driven clutch member until surface 44- engages surface 46. The upper portion of driven clutch member 45 is provided with an annular groove 47 for the reception of a rope starter when housing 17 and its associated parts are removed. In the illustrated embodiment, a perforated annular metal screen 4S is secured to an intermediate portion of driven clutch member 45 so as to rotate therewith. This screen, which forms no part of the present invention, is so placed as to prevent foreign particles carried by the air stream from entering the internal-combustion engine.

Mounted on housing 17 is a switch button 49 of ,circular shape, this button having a downwardly projecting central post l) held to the upper portion of shaft 3'7 by means of a washer 51 and screw 52. A coil compression spring 53 is disposed between the upper surface of housing 17 and the undersurface of button 49, this spring serving'to hold the button in its Vupper position. The force of spring S3 is considerably weaker than the combined forces of the three springs 21 which hold housing 17 in its upper position. T ius, when an operators palm is pressed downwardly on domeshaped housing 17, switch button i9 will be depressed before housing 17 is moved to its lower position. A switch operating pin 54 isformed on the undersurface of button 49 and projects downwardly through a clearance aperture in housing 17. Thispinis connected by means of a spring 55 to the actuating button 5,6 of anon-off switch 57 mounted within housingyiby means of a bracket 58. An electrical conduit 59 connects switch S7 to motor 27 and to a receptacle 61 mounted'on the side of housing 17 alongside motor 27. The arrangement is such that when a power supply such as a volt supply conduit or a battery connection is plugged into receptacle 61, motor 27 will be de-energized as long as button 49 is in its upper position, but will be energized through closing o-f switch 57 when button 49 is depressed.

In operation, assuming that the parts are initially in the position shown in the drawings, an electrical power supply conduit will first be plugged into receptacle 61. The operator, in order to start the internal-combustion engine, will place his hand over the central portion of dome-shaped housing 17 and press downwardly thereon. During the initial portion of this movement, switch button 49 will be depressed, closing switch S7 and energizing electric motor 27. This will cause rotation of driving clutch member 38, which is still disengaged from driven clutch member 45, through pinion 33 and gear 43. Further downward pressure by the operator will force housing 17 and its associated parts downwardly against the action of springs 21, bushings 19 sliding downwardly along posts 15 during this operation. Surface 44 of -rotating clutch member 38 will approach surface 46 of driven clutch member 45 which is mounted on crankshaft 12. As these surfaces become engaged, the crankshaft will be driven through the clutch, and this action will continue as long as the operator presses down on housing 17.

When the engine has been started, the operator need only release his hand from housing 17. Switch button 49 will move upwardly, causing switch 57 to open and deenergizing motor 27. As housing 17 is lifted due to the action of springs 21, driving clutch member 38 will move away from driven clutch member 45, thus disengaging the clutch and entirely isolating motor 27 from the moving parts of the internal-combustion engine. Housing 17.and the parts mounted thereon will come to rest in the original position shown in the figures, with the upper surface of bushings 19 engaging portions 23 of stop pins 22. If it should be desired to start motor 11 manually, stop pin portions 23 may be rotated 90, thus permitting housing 17 and its associated parts to be withdrawn upwardly, slots 24 of bushings 19 passing over portions 23 during this process. A rope starter (not shown) may then be wrapped around exposed groove 47 and the crankshaft rotated directly.

While it will be apparent that thepreferred embodiment of the invention disclosed is well calculated to fulll the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is: v

1. In a starting assembly for internal-combustion engines, a dome-shaped housing, means foi-mounting said housing on the exterior ,of an internal-combustion,engine for movement toward and away from the engine, spring means urging said housing away from said engine, limit stop means holding said housing in an outer limiting position, an electric motor secured to said housing and movable therewith, a driving clutch member rotatably mounted within said housing, means drivingly connecting the shaft of said motor with said driving clutch member whereby rotation of said motor will cause rotation of said driving clutch member, a driven clutch member on said engine and connected to the crankshaft thereof, said driven clutch member being coaxial with said driving clutch member whereby movement of said housing toward said engine will cause ,engagement of said clutch membersa switch .in the circuit of said electric motor, said switch being movable between a normally open position and a closed position, a switch operating member mounted -on the exterior of said housing, .the position of the said switch operating member being such that it is accessible to the housing being movable between a first position away from' said engine and a second position toward said engine, spring means urging said housing into its first posiuon, a driving clutch element rotatably mounted within said housing, said driving clutch element being so disposed as to be disengaged from said driven clutch element when said housing is in its first position and engaged with said driven clutch element when the housing is in its second position, an electric motor mounted on and movable with said housing, reduction gearing connecting said motor with said driving clutch element, a power supply circuit for said motor including an on-oi switch mounted within said housing, a control button for said switch mounted on the exterior of said housing, said button being movable between an olf position away from said housing and an on position toward said housing, and spring means urging said control button to its iirst position.

3. In combination with an internal-combustion engine, a starting assembly comprising a driven clutch element carried by said engine and connected to the crankshaft thereof, a dome-shaped housing mounted exteriorly of said engine with the open end thereof facing said engine, a peripheral flanged portion formed on said housing, a plurality of guide posts xed to said engine and extending through said flange, means carried by said guide posts for limiting the movement of said housing away from said engine, a plurality of springs urging said housing to its outward limiting position, a driving clutch member disposed within said housing, said driving clutch member being disengaged from said driven clutch member when said housing is in its outward limiting position and being engageable with said driven clutch member when said housing is moved toward said engine, an electric motor carried by said housing, reduction gearing connecting said motor and said driving clutch member, a power supply circuit for said motor including an on-oif switch mounted within said housing, a switch control button mounted on the exterior of said housing and engageable by the hand of an operator pressing onl said housing against the action of said springs, said button being movable between an outer position in which said switch is open and an inner position in which said switch is closed, and a spring urging said button to its outer position.

4. The combination according to claim 3, the means for limiting the outward position of said housing comprising a stop element rotatably mounted at the outer end of each of said posts, said stop elements being manually movable between a first position in which said elements engage said housing and a second position in which said stop elements are in non-obstructing relation with said housing, whereby the housing may be withdrawn from its operative position.

5. The combination according to claim 4, said stop elements being of elongated shape, and slots in said housing flange adjacent said stop elements, whereby said stop elements will be aligned with said slots when the stop elements are rotated to their second position.

6. In combination with an internal-combustion engine, a starting assembly comprising a driven clutch element carried by said engine and connected to the crankshaft thereof, a dome-shaped housing adjacent the exterior of said engine and surrounding said driven clutch member, a peripheral tianged portion on said housing, a plurality of guide posts connecting said anged portion and said engine, said housing being slidable between an `outer position and an inner position with respect to said engine,` springs urging said housing toward its outer position, a driving clutch element rotatably mounted within said housing fand coaxial with said driven clutch element, said clutch elements having cooperating surfacesV engageable when said housing -is moved from its outer to its inner position, an electric motor carried by and movable withI said housing, a power supply circuit for said motor including an on-of switch mounted within said housing, a switch control button mounted on the exterior of said housing and in alignment with the axis of said clutch members, said button being movable between an outer position opening said switch and an inner position closing said switch, and a spring urging said button to its outer position.

7. The combination according to claim 6, said motor extending vfrom one side of said housing, the axis of said motor shaft being transverse to the common axis of said clutch elements.

8. The combination according to claim 7, said gearing comprising a bevel pinion on said motor shaft, and a bevel gear formed on a surface of said driving clutch element and meshing with said pinion.

9. The combination according to claim 8, further provided with an outboard bearing support for said motor shaft on the side of said pinion oppositesaid motor, and supporting means for said bearing support extending from the inner surface of said dome-shaped housing;

10. The combination according to claim 7, said housing being provided with a side wall adjacent said motor,

and a receptacle in said motor power supply circuit A mounted on said side wall, whereby a power supply conduit may be connected in said circuit.

1l. The combination according to claim 7, the force of said switch button spring being weaker than the cornbined forces of said housing springs when said housing and said button are in their outer positions.

12. In combination with an internal-combustion engine, a starting assembly comprising a driven clutch element secured to the engine crankshaft and projecting outwardly from the engine, a mounting ring secured to said engine and surrounding said clutch element, a plurality of posts secured to said mounting ring and extending outwardly therefrom, a dome-shaped housing disposed outwardly of and surrounding said clutch element, peripheral portions of said housing being slidably mounted on said posts, stop elements carried by the outer ends of said posts for limiting the outward movement of said housing, springs urging said housing toward its outward limiting position as defined by said stop elements, the stop elements being movable between a locking position and a releasing position, a supporting shaft secured with in said housing, a driving clutch element rotatably mounted on said shaft and coaxial with said driven clutch element, said clutch elements being engageable when said housing is moved inwardly from its outer limiting position, a thrust bearing carried by said shaft on the side of said driving clutch element opposite said driven clutch element, an .electric motor secured to and movable with said housing, the shaft axis of said motor being transverse to the clutch axis, a pinion on said motor shaft, a gear on said driving clutch element meshing with said pinion, a power supply circuit for said motor, an on-oif switch in said circuit and mounted within said housing, a switch button mounted on the exterior of said housing and coaxial with said clutch axis, means limiting the outward movement of said switch button with respect to said housing, a spring urging said button to its outer position, and means connecting said button and said switch for causing the switch to be open when said button is in its outer position and closed l I iassantisaid clutch element, an Velffctri1rn trazrd'by 'd hulsing, a driving pinion 'onnecfe'd t0 .Sad 'mtr VFatLancl a combined irivngaar and driving clutoh memb'rotatably mounted in said housing, said membor being of integral construction and having a hub por# tion, a gea; portion extending substantially radially from* said Vhub portion, a plurality of gear teeth formed on one S A A Surface 0fI Ysaid. gear portion and mhng with .Said PinQn, and an V*afnnullf' clutch' portion extending axially from the oher sido of said gaar portion, t/he interualisurface of said clutch portion being flayed to interit with $aid 5 driving clutch element.

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