US1700130A - Starter - Google Patents

Description

Jan. 29, 1929.

C. J, W. HAYES STARTER Filed llay 1923 2 Sheets-Sheet 1 INVENTOR. 1/: M w

ATTORNEY.

Jan. 29, 1929.

c. J. w. HAYES sum-ran Filed llay 9, 1923 2 Sheets-Shoot 2 AEZiT'iJY r INVLNTOR.

- fiarzas' J a ATTORNEY.

Patented Jan. 29, 1929.

UNITED STATES" PATENT OFFICE.

CHARLES J. W. HAYES, OF ROCHESTER, MICHIGAN.

STARTER.

Application filed May 9, 1923.

This invention relates to starters for internal combustion engines andhas for its object a starter which'is especially designed to be used in an automobile and to be actuated by an electric motor.

Starters that are now in general use in mo tor vehicles in this country employ what is commonly called the Bendix drive and are described and claimed in the Bijur and Bendix patents. These starter drivesall operate on the principle of utilizing a sudden torque on the starter shaft, coupled with the inertia of the driving'pinion causing the pinion to travel longitudinally of its axis, and engage with the teeth of the large starter drlven gear. The disengagement of the driving pinion takes place when the engine starts,

the gear caused to'suddenly accelerate and the driving pinion thereby caused to travel back longitudinally out of engagement with the gear. This longitudinal traveling move ment is effected by mounting the pinion, on a threaded sleeve.

This type of starting apparatus depends altogether upon a sudden turning torque to engage the pinion with the gear and acceleration of'the turning movement of the gear over that of the pinion todisengage the pinion with the gear. It requires a screw driving connection or its equivalent between the pinion and the starter shaft in order to provide the longitudinal movement of the pinion necessary to engage and disengage the gear and pinion. This is the law of its operation.

It is the object of my invention to design a starter which operates on a wholly different principle and which in no way depends upon sliding gears or a screw; nor does itdepend upon sudden torque, or acceleration to engage the driving member and driven member. The principle of operation is wholly different. I employ a sectional driving member having movable engaging sections which are controlled by centrifugal force due to rotational speed and in no way depend upon a sudden starting torque or sudden acceleration of the rotational speed, although such sudden acceleration if applied is not detrimental to its action. This has many advantages,- as will be described hereinafter, over the type of driving member which depends upon sliding gears and a screw. 1

I employ a yieldable driving connection, a sectional driving member and a starter motor shaft. This, however, is an ordinary use of the flexible driving connection for the pur- Serial No. 637,848.

pose of easing sudden loads on a driving shaft. 0 novelty is claimed for this driving connection between the starter driving member and the starter motor shaft so far as its general use is concerned.

However, I do provide a new and novel coupllng between this flexible driving connectlon and the sectional drivin member for the purpose of disengaging tie yieldable driving member under any abnormal increase of the load which is often due to back-firing of the engine. I This coupling automatically dlsengages and upon the cessation of the abnormal condition automatically re-engages. This makes a very valuable improvement in any starter which employes a yieldable'drivmg connection as all starters which I am familiar with are open to the objection that back-firing of the engine often shears the fastenlng screw and breaks the spring or otherwise damages the parts. These features Wlll be more fully explained in describing the structure in detail.

In the drawings:

Fig. lis a fragmentary elevation of the starting mechanism.

F 2 is a longitudinal section of same.

F 1g. 3 is a section taken on the line 33 of Fig. 2.

Fig. 4 is a section taken on the line 44 of Fig. 2.

Fig. 5 is a section taken on the line 5-5 of Fig. 2,'the parts being at rest.

Fig. 6 isa section taken on the same line with-the parts in motion as the starter begins the cranking operation. j

Figs. 7 and 8 illustrate a slightly modified form of the invention and show the parts intwo differentpositions that are assumed while in motion.

Fig. 9 is a longitudinal section of still another modified form' intended for use on relatively cheap cars. F Fig.' 10 1s a section on the line 10-10 of a is the large gear (designated the starter driven gear) which is ordinarily on the flywheel of the engine and which ordinarily is provided with chamfered teeth to permit sliding gear engagement. In my construction the teeth do not have to be chamfered spaced around a body part which is free to oscillate on the driving shaft and is connected thereto through the medium of a spring.

These engaging membersare in a sense, toothlike and are intended to engage the toothed driven member. These centrifugally controlled engaging members are preferably in the form of double cranks b as shown in Fig. 1, wnere they resemble the crank throw of a gas engine shaft, or they may be a simple crank as shown at c in Fig. 9, or they may take the form of pivoted dogs or pawls d as in Figs. 7 and 8. The essential thing is that these engaging sections are pivoted with respect to the body of the starter member so that a suflicient speed of rotation of the body of the starter driving member throws these centrifugally controlled sections into engagement with the starter driven member, which is toothed. The starter driven member has flanges that straddle the starter driven member (that is the large gear) and this enables the engaging members to be pivoted or fulcrumed near the periphery of the flanges so that when they pass the large gear, they are on the inside of the pitch line and hence are pulled into mesh with the teeth of the gear. I find that this is very desirable to make a successful starter drive of the type that I have described.

The teeth of the starter driven gear may be ordinary standard gear teeth as shown in Figs. 5 and 6 or may be. specially out teeth with rounded gullets that more or less resemble ratchet or saw teeth. Preferably, l lace a spring wire 6 around the grooved ends of the double cranks b as shown in Figs. 1 and 4. This places a slight amount of friction on these parts so as to make the operation of the centrifugally controlled engaging sections free from gravitational movement and rattle in any position of use.

For instance with a starter having the starter drive member on the right hand side of the fly wheel gear, there is a tendency of the engaging members to drop out against the gear when in a position of rest. This will cause a constant clicking and the wearing of the engaging members were it not for this means for counteracting the tendency of gravity. As soon as the teeth of the large gear throw the engaging members out of their path once, there is enough friction secured by this spring to prevent the engaging members dropping back into contact with the teeth. However, this friction is not sufficient in any way to materially interfere with the throwing of the engaging member out by centrifugal action under high rotational speeds.

The starter shaft is designated and a flat helical spring 9 is secured to the end. of the shaft with a set screw it. The body of the starter driving member is provided with a hub ihaving an internal annular groove and the perforation 72 through the hub at the groove. Into this perforation is adapted to engage the rounded head on of a rivet or pin on the end of the spring g. This head being rounded or beveled, it will be obvious that when any load of unusual proportions is transmitted to the spring and the spring thereby sufficiently reduced in diameter by winding up this rivet head will slip out of the perforation and run around in the groove j thus relieving the strain and the danger of breakin When the strain is relieved the rivet head will drop back into the perforation when it again passes the perforation at a sufficiently lowered speed. This I consider a valuablesimprovement in starters in general as it takes care of the breaking strains placed upon the yielding drive coupling due to backfiring, and other causes, the coupling parting before breaking takes place. It will be noticed that my use of the coil spring is quite different from the way the coil springs are made and used in successful starters heretofore designed- In starting devices that use a longitudinally traveling pinion on a screw, the coil spring has two import-ant functions. One is that it affords a yielding driving connect-ion such as is common in machinery which is subjected to sudden increases of load, and it performs the additional functions of cushioning and yielding to the driving pinion when it misses mesh with the driven gear under compulsion of the screw. This last function I in no way use or require in my apparatus but simply use the springas a torsion spring to provide the ordinary yielding driving connection. between the driving member and the driven member which may be subjected to surden increase in load.

The exact rounding and dimensions of the head of the rivet and the diameter and cross section of the spring strip is a matter more or less of cut and try, as the proportions have to be such that the coupling cannot only pick up the ordinary increase of the load due to the coupling up of the starter shaft to the fly wheel gear without letting go, but must release at a slight increase of strain above normal but well helowthe breaking pointof the parts. This, of course, is something that is well within the skill of any good mechanic, and which cannot be expressed by any definite data that I can here set forth, as it varies with the running conditions to be met.

It will also be noted that my yieldable driv ing connection is directly between the shaft and the body of the starter driving member.

I find that by actual experience it is very desirable to have the circular pitch. the distance between the engaging members slightly greateiuthan the circular pitch of the gear teeth of the driven member, otherwise they sometimes interlock. With a given tooth ratio the center distance between the gear and the body of the driving member need not be an exact distance as would be required if they were pinion and gear of the ordinary type.

' Another feature of construction to which I desire to call attention is that in the double form of crank shown in the drawings these cranks overlap in such a way that the distance that they are thrown out by centrifugal force is limited; with a single form crank shown in the drawings I use a guard retainer to prevent their being thrown out beyond a certain distance and also to hold them in their sockets.

The operation of the device is simple. When the starter shaft is at rest the engaging sections (or perhaps only a few of them) rest in the position shown in Fig. i so that there a clearance between the driving members and the large gear. However, when turning effort is exerted on the starter shaft 7", Whether a sudden turning effort or a slow one,-after a certain speed is reached, centrifugal force throws out the engaging sec tions p and they are thrown into engagement with the teeth of the driven member, and by them, because of the angular relation of the pivoted portion of the driving member in engagement thereto, held in tight mesh until the angle has sui'licientiy changed by rotation when the action pulls them out of mesh. This is clearly shown in Figs. 6, 7 and 8. Now, when the engine actuates the large gear, this does not automatically throw out of operative relation the driving member, but the device works upon the principle of an overrunning clutch. The teeth of the large gear simply travel faster than the engaging members and the engaging members are forced idly out of the way by the overrunning driven memher.

In short, my centrifugally controlled sectional driving. member amounts in substance to the incorporation of a centrifugally controlled radially acting over-running gear action in a starter mechanism, and is I believe, novel and entirely different in its mode of operation.

hat I claim is: v

1. In a starting apparatus for internal combustion engines, the combination of a starter driven member, a starter driving member of fixed axis of rotation relative to said driven member and provided with a plurality of centrifugally controlled movable driving sections which are each fixedly guided on the driving member, each of the driving and driven members having its axis of rotation outside of the periphery of the other member.

2. In a starting apparatus for internal combustion engines, the combination of a toothed starter driven member, a starter driving member of fixed axis of rotation relative to said driven member, comprising an overrunable member with centrifugally controlled suitably guided sections arranged to positively engage and drive the starter driven member when suflicient speed is attained.

3. In a startmg apparatus for lnternal combustion engines, the combination of a toothed starter driven member and a starter driving member of fixed axis of rotation relative thereto, said driving member comprising a plurality of centrifugallypositioning toothed sections pivoted to the driving member normally in a position of clearance with respect to the starter driven member and arranged to mesh in running relation with the starter driven member by centrifugal act-ion when sufiicient speed is attained.

4-. In a starting apparatus for internal combusion engines, the combination of a starter driven member, a starter driving member, the latter comprising a rotatable member with a plurality of movable centrifugally-controlled overrunable sections for engaging the driven member, and a spring to apply to said movable sections a preventative of gravitational action.

5. In a starting apparatus for internal combustion engines, the combination of a starter driven member and a starter driving member, the latter comprising a plurality of centrifugally-controlled overrunable driving sections in the form of cranks arranged to be positioned for engagement with the driven member by rotation of the starter'driving member, said driving member having a fixed axial relation to the driven member.

6. In a starting apparatus for internal combustion engines, the combination of a gear wheel and a starter driving member in the form of a body carrying a plurality of, centrifugally thrown out and separately acting and controlled meshing sections normally having clearance with respect to the gear teeth, but engaging the teeth to drive the gear when the starter is speeded up.

7. In a starter apparatus for internal combustion engines, the combination of a starter driven member provided with teeth and a starter driving member comprising a plurality of radially thrown and independent tooth engaging sections which are caused to mesh with and drive in geared relation the toothed driven member when the starter driving member is speeded up, said driven and driving members having a fixed center distance.

8. In a starting apparatus for internal combustion engines, the combination of a starter driven member provided with teeth on a pitch circle, and a starter driving memleer in fixed axial relation thereto comprising a plurality of movable sections that normally have clearance with respect to the teeth of the driven member but which are caused to mesh in running relation with said teeth; each section having some independent relative movement when the starter driving member is speeded up.

9. In a starter apparatus for internal combustion engines, the combination of a starter driven member and a starter driving member, the latter including a plurality of independently relatively movable driving sections of crank-like form and With crank throws to engage the driven member When the driving member speeds up and which are capable of being overrun When the driven member is accelerated.

10. In a starter apparatus for internal combustion engines, the combination of a starter driven gear and a starter driving member comprising a flanged body member provided with a plurality of crank-like tooth parts co-operating with the driven gear and controlled by centrifugal force and pivotally supported in the flange.

11. In a starter apparatus for internal combustion engines, the combination of a toothed starter driven member and a starter driving member comprising a two-flanged body and a plurality of double crank-like centritugally controlled tooth parts pivoted to the flanges and arranged to be thrown out into mesh with the teeth of the driven member when the driving member speeds up.

12. In a starter apparatus for internalcombustion engines the combination of a starter driven member provided with teeth arranged in a pitch circle and a starter driving member provided with a plurality of ensections pivotally supported in a circle, the relation of driven to driving members being such that the pitch circle of the one intersects the pivot circle of the other.

In testimony whereof I affix my signature.

CHARLES J. W. HAYES.

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