US2156667A - Engine starting mechanism - Google Patents

Description

May 2, 139.- R. M. NARDONE 2,156,667

ENGINE STARTING MECHANISM Original Fuezrxvla 17, 1934 2 Sheets-Sheet 1 llll /i INVENTOR. a

B Romeo wardens A ORNEY.

lllllllmu V" May 2, 1939. R. M. NARDONE ENGINE STARTING MECHANISM ZSheets-Sheet 2 Original Filed May 17, 1934 I Patented May 2;, 1939 ENGINE STARTING MECHANISM Romeo M. Nardone, East Orange, N. J., assignor to' Eclipse Aviation Corporation, East Orange,

N. J., a corporation of New Jersey Substituted for application Serial No. 726,159, May 17, 1934. This application March 24, 1938,

Serial No. 197,971

2 Claims.

This invention relates to engaging and driving "mechanism for rotary parts, and more particularly to a 'novel mechanism for starting an internal combustion engine.

5' An object of the invention is toprovide a multiple ratio driving connection which will act.

automatically to take up the back-lash characteristic of certain driving mechanisms of the prior art when one member overruns the other.

The invention, although not confined to any particular type of starter, is particularly applicable to inertia starting devices, and the invention isshown in the accompanying drawings as embodied in an inertia" starter of the 'delayed mesh type,

It is a known fact that a large amount of the energy developed in the driving motor, or stored in the flywheel (when the'starter is of the inertia type) is lost in friction due to the slipping 0 of the clutch. The greater the mass to be accelerated, the greater is this loss. The starter begins to crank the engine at a speed of, say, 90 R. P. M. and since the engine cannot immediately assume this speed, a period of clutch slippage occurs. Slippage ceases when the engaged engine and starter parts have reached the same speed. If the'mass to be accelerated is large, slippage increases, reducing the speed of the flywheel and at the same time reducing the maximum speed of the engine. Accordingly, another object of the present invention is to reduce the amount of energy lost in clutch slippage, thereby increasing the efiiciency of the starter. Other desirable features are also obtained as will be evident from an examination of the following specification and the accompanying drawings.

Only two embodiments of the present invention are-shown in the accompanying drawings, but it is to be understood that the drawings are 3 for the purpose of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the, appended claims. C

Referring to the drawings, 5 Fig. 1 is a central longitudinal section of a device embodying the invention;

Fig. 2 is a transverse sectional view partly in elevation taken substantially along the lines 2-2 of Fig. 1; Fig. 3 is a sectional view of a portion of a second embodiment of the invention; and

Figs. 4 to 9 are views of details of said second embodiment.

Referring to the drawings, there is disclosed i a combined hand and power actuated starter of a conventional type. As shown, the starter includes a flywheel 2 constituting an inertia element, and an engine engaging clutch element 3 which is movable into driving engagement with a corresponding clutch member 4 provided on or convl5 necting with the crankshaft or crankshaft extension of the engine to be started. The mechanism is housed within a suitable casing constituted preferably by an inner section 5, intermediate'sections t and/l, and a motor casing 8, the 10 sectionsbeing rem'ovably secured together in any suitable manner, and the innersection E'being provided with a flange 5a to receive bolts 9 for mounting the starter on a flange ll] of the engine crankcase.

The manually operable means for actuating the starter preferably takes the form of a cranking shaft rotatably mounted in intermediate housing section I with the outer end (not shown) projecting from said housing, and provided at its inner end with suitable means, such "as a bevel pinion I I, for meshing engagement with a similar pinion l2 keyed, to a shaft l3 constituting an integral extension of the closed end of a barrel to be further described. The said shaft I3 is 25 further provided with bushings on which are rotatably mounted two pinions [4, one being integral with internally toothed gear 15 adapted to mesh with gear teeth l6 formed near one end of a shaft H, the said shaft n being adapted for operative connection, through novel means to be hereinafter described, with a stub shaft 20 to wall 23. i

The gear I5 is provided centrally thereof with an integrally formed pinion It, as above pointed out, and said pinion I 4 constitutes the sun gear .for a plurality of planetary gears 5|, one of which is shown in section in the drawings, and one in elevation. These planetary gears 5|,of which three are preferablyemployed, spaced at intervals of one hundredand twenty (120) degrees about the sun gear 14, mesh with an internally toothed ring 52 which is rigidly secured in any suitable manner to the inner surface of housing section 5, such as by screws 52a. Each planetary gear is rotatably mounted, why a bearing 53, on 56;

a sleeve 54, the inner end of each sleeve bein received in a spider or cage member having a hub integral with a second pinion I4 meshing with a second set of planets operatively connected with barrel 3|]. Barrel 30 is preferably mounted on bearings, as shown at 56 and 51, the former being ,held in position by'flange 58 of the barrel, and

the latter by nut 59 and spring wire 6| clamped thereto, and also to the barrel as indicated at 62. A retaining ring 66 carried by the outer endsof the screws 55 maintains bearings 53 in their proper positions onsleeves 54-. l

A multiple disc clutch is preferably provided in association with the barrel 36 to insure relative rotary movement between the engine engaging member and the train of gearing above described, whereby the latter is protected from damage due to an excessive shock or load. As shown, the disc clutch comprises a plurality of interleaving discs 19, alternately splined to the inner surface of the barrel 36 and the outer surface of a shell 80, internally threaded toengage a correspondingly threaded screw shaft 15, to be further described. Resilient means, such as a plurality of coiled compression springs 8|, the pressure of which is adjustable by a nut 82 threadedly engaging the end 83 of the barrel, are provided to press upon a flange on member 66, and thus maintain Lie discs 19. in frictional engagement with a pressure sumcient to insure transmission of torque from barrel 30 to shell 80, up to a predetermined capacity.

Fitted over the inner end of the starter is a cup-shaped member 89, that is preferably formed of metal and is provided with a flange 9| adapted to be clamped between flange 5a of the starter housing, and the engine flange Ill. The inner portion of member 69 is bent inwardly toward clutch member 3, as at 93, and is provided with a central opening which is slightly larger in diameter than the outerdiameter of the clutch member 3.

In order to prevent seepage of oil through the central opening in member 89, the latter preferably carries a washer 94 of leather or equivalent material. Normally the inner portion of washer 94 is held in engagement with-the adjacent surface of the head of clutch member 3 by means of a metallic washer and a flange sleeve 91.

Rod H1 is axially movable through a central bore in the screw shaft 15, preferably by-means of the usual shifter fork as shown at I I9 in Fig. 1,

I2I oscillated by a suitable lever or bell crank as indicated at I22, and corresponding to that shown at 55 in the Patent No. 1,786,118 granted to Raymond P. Lansing on December 23, 1930.

The rod is reduced in diameter as indicated at I24 to provide a shoulder abutting the end surface of the screw shaft 15, the rod being efiective through the instrumentality of said shoulder to move the screw shaft axially until further motion is prevented by engagement of the stop nut I26 with the annular ledge I21 formed at the end of the unthreaded portion of the inner surface of the shell 80. Axial movement of the screw shaft 15 is transmitted yieldably to the engine engaging member through the instrumentality of a coiled compression spring I28 which surrounds the rod H1 and presses upon the washer I29 abutting the transverse portion I3I of the engine engaging member 3. A nut I32 provides means for adjusting the connection between the rod I I1 and member 3.

Having now described the construction of a 'as shown at I61.

conventional inertia starter of the character to which the present invention is well suited, there remains to be described the novel features of this invention.

Referring to the drawings, two different size pinions I40 and I M are secured to the flywheel. These mesh with difierentsize gears. I42 and I43. As best viewedon Fig. 2, gear I42 has internal cam shaped depressions I44 for overrunning clutch rollers I 46; The inner race I 41 is round and is internally threaded for the reception of screw I48- having a long hub extension to movable cone clutch member I 49 splined to shaft I1. Gear I43 is mounted by a frictionless bearing on the screw extension I 48 and supports gear I42 by means of a ball bearing. It has a cone face to fit cone I5I. The latter is backed up by a spring I52 forcing the two cones together.

The flywheel is brought up to speed either by an electric motor IUI or by manual means. If by hand, gear I5 drives pinion I6 which drives cone clutch I5I. The latter being in engagement with gear I43, drives it and drive is transmitted to pinions I4I and I40. Pinion I40 drives gear I42 at a speed less than that of gear I43, thus overrunning. The centrifugal force on rollers I46 acts against gear I42 and offers no drag-resist- When the flywheel is up to speed and the starter engaged to the engine, the drive is transmitted from pinion I4I to gear I43 to cone clutch I 5| and tends to crank the engine at high speed. However, the torque value of this cone clutch is such that it slips before the clutch 19 slips. After the starter is engaged, all gears tend to' come to rest. Therefore, as cone clutch slips. gear I42 will catch up and drive shaft I1 through the roller clutch I46, I41. Torque between I41 and I 48 acts to move the latter to the right because of -the thread and thus hold cone I5I away from gear I43. After the engine member 4 has been accelerated to a certain extent, the load on the starter diminishes sufliciently to' cause the torque responsive member I48 to return to the left. Spring I52 now returns the cone clutch I5I into driving position, and an increased cranking speed results.

The second period of slippage accelerates the engine still further, but the total loss is less than would occur with a single reduction starter in bringing the engine up to equal speed. For the same engine speeds the flywheel can be reduced in size, or for equal flywheels and the same loss in energy, the engine can be accelerated to a higher speed.

In the modification shown in Figs. 3-9, the lower speed gear I42 has a plurality of camsurfaced recesses I6| at angularly spaced intervals, each containing a ball I62 and cooperating with correspondingly formed recesses I63 in a jaw clutch element I64 (shown in Fig. 9) having teeth I65 engaging corresponding teeth I68 on the associated clutch element I66 (as viewed in Figs. 7 and 8) whose hub is splined to shaft I1, On the remote side of clutch element I66 are one or more projections I69 (Fig. 6) mating with grooves I10 in an inertia disc I1I (shown in Figs. 4 and 5) which is free to rotate on shaft I1 and abuts an axially fixed clutch thrust bearing 26. Cone clutch element I49 has a marginal flange I13 locking it to clutch member I 64, and it faces in a direction opposite to that of Fig. 1 to engage the gear I43, the bearing I14 taking the thrust of engaging spring .I52. A second spring I15 is provided to tend to hold clutch element I66 out of engagement with clutch element I64, and a stop washer I16 restrains the outer end of spring I52.

The operation of the starter of Fig. 1, when revised to include the structure of Fig. 3 in lieu of the corresponding elements of Fig. 1, is as follows:

After the flywheel 2 has been accelerated (by either of the means previously described) to the desired speed, and the members 3 and 4 meshed, the cone clutch I43, I49 slips under the load thus imposed. This slipping permits shaft I1, and the parts splined thereto, to decelerate, whereupon inertia disc I'll runs ahead of clutch element I66, camming the latter into mesh with clutch element I64. Gear I42 now takes up the drive, and in doing so it cams balls I62 to the left and causes a corresponding leftward movement of clutch elements I64 and I49, whereby the former is more firmly meshed with the driven clutch element I66, while the cone clutch elements I43 and I49 are separated. I'he resulting drive through parts I66, I? et seq., accelerates the engine to a certain extent, or until the load diminishes sufllciently to enable spring I52 to reengage cone clutch I43, I49; the balls I62 at the same time receding in recesses I6I and I63, and thereby enabling spring I15 to again disengage clutch teeth I68, I65, and hold said clutch teeth disengaged while the drive to the engine proceeds through elements IM, I43, I49 and I1 until the starting of the engine is completed, unless the load again becomes excessive, in which event the cycle is repeated.

An important feature of this invention is th following:

An engine may fire once or twice, and then cease firing. As it fires, it will tend to run ahead of the starter. However, since the normal starter cannot follow up, all the energy imparted to the engine by the explosion is lostand it has to decrease its speed enough to allow the starter to catch up. With the present invention, when firing occurs and the engine speeds ahead, the high speedcr-anking gears will immediately go in action and cranking speed will be increased. This will cause the starter to keep pace with the engine as it fires while permitting the low speed gears to do the actual cranking.

This application is a substitute for my application Serial No. 726,159 filed May 17, 1934.

What is claimed is:

1. In an engine starter of the inertia type, the combination with high andlow speed shafts, of a high speed fly wheel mounted on said high speed shaft, accelerating means for said fly wheel, said accelerating means including a friction clutch operatively connected with said low speed shaft and having a toothed member forming a part thereof, a pinion on said high speed shaft meshing with said toothed'member, a one-way clutch operatively connected with the low speed shaft and including-a toothed member, a second pinion on said high speed shaft meshing with the toothed member of said one-way clutch, the ratio of the first named pinion and toothed member and the ratio of the second named pinion and toothed member being such that the one-way clutch overruns while said accelerating means operates to accelerate the fly wheel through the first named clutch.

2. In an engine starter of the inertia type, the

combination with high and low speed shafts, of a high speed fly wheel mounted on said high speed shaft, accelerating means for said fly wheel, said accelerating means including a friction clutch operatively connected with said low speed shaft and having a toothed member forming a part thereof, a pinion on said high speed shaft meshing with said toothed member, a one-way clutch operatively connected with the low speed shaft and including a toothed member, a second pinion on said high speed shaft meshing with the toothed member of said one-way clutch, the ratio of the first named pinion and toothed member and the ratio of the second named pinion and toothed member being such that the one-way clutch overruns while said accelerating means operates to accelerate the fly wheel through the first named clutch, means for meshing the starter with an engine member to crank the latter, and means effective upon a predetermined slippage in said friction clutch during operation of the starter to crank the engine member, to render the one-way clutch operative to transmit torque from the fly wheel to the low speed shaft.

ROMEO M. NARDONE.

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