US2002413A - Engine starting mechanism - Google Patents

Description

May 2l, 1935. R, M. NARDoNE ENGINE STARTING MECHANISM Filed Oct. 2, 1950 H Wl IH Ifll m l ,I l M5 WI v Ihllhlll l w V i .H mw u Il mm I. Sw f i -il ,X

mw kw mV wx. www, HHHMJJIW lr O e. n N Rvm .MD/Y om .O l M www Mm m @a B u N Q f Patented. May 2l, 1935 UNITED STATES PATENT oFFicE 2,002,413 .ENGINE STARTING MECHANISM Romeo M. Nardone,

East Crange, N. J., asslgnor to Eclipse Aviation Corporation,

East Orange,

N. J., a corporation of New Jersey Application October 2,

3 Claims.

5 plying medium.

An object of the invention is to provide in a device of the foregoing character, novel means or securing an initial turning movement of the power shaft of the engine to be started.

Another object of the invention is to provide in a device of the foregoing character novel means for turning over the power shaft of the engine to be started at two or more different speeds.

A further object of the invention is to providev novel means for selecting which of two or more speed transmitting mechanisms is to be used to supply the initial torque for driving the engine.

A Still another object is to provide means for accelerating the engine starting apparatus after the initial engagement of said apparatus with the member to be driven.

Still another object of the invention is to provide novel means for automatically rendering ineffective the initial driving connections after the initial turning movement has been transmitted to the member to be driven.

A further object is to provide novel speed increasing Amechanism for multiplying the initial speed of rotation of the starting mechanism so as to transmit the turning power to the member to be driven at a speed most suitable for the performance of the desired function.

Another object of the invention is to provide a comparatively simple, eilicient and reliable apparatus for the purposes stated, and in which a saving of electric motive power can be effected.

A further object is to provide an invention of the foregoing character which may be readily accessible for inspection or replacement of parts.

Other objects and advantages to be derived from the use of the novel mechanism consti'- tuting the presentinvention will appear from an inspection of the following specification with reference being had to the accompanying drawing wherein the embodiment at present preferred is shown by way of illustration of the invention.

It is to be expressly understood however that the drawing is for the purpose of illustration and description only, and is not designed as a definition of the limits .of the invention,A reference being had for this purpose to the appended claims. p

In the drawing, wherein like reference char- 1930, Serial No. 486,026 (Cl. 74-7) acters refer to like parts throughout the several views,

Fig. 1 is a view in elevation, partly sectioned, of a mechanism embodying the invention; and

Fig. 2 is a transverse sectional view along the line 2 2 of Fig. 1.

Referring more particularly to the drawing, the embodiment of the invention illustrated comprises a drive proper including a driving member which is adapted to engag a member of the eng gine to be started, and also reduction means combined with such drive proper and operated in A suitable manner and by suitable means such as an electric motor as herein shown.

First describing the drive proper,' the same is located within the forward portion of casing I which is suitably supported as being detachably connected with the crankcase of the engine in suitable manner as by means of the flange 2; the rear portion being connected to the forward portion as shown at 3. Within a bushing 4 in the casing, there rotates a driving barrel 5 and a shell or nut 6 concentrically arranged therewithin and providing a considerable annular space between them to receive a yieldable driving connection which is here shown in the form of a friction clutch 1. This clutch is composed of two sets of clutch plates or disks which are splined `respectively to the interior of the barrel and the exterior of the shell. The means preferably employed for exerting pressure upon these plates comprises a series of coil springs I located in a part of such annular space, their pressure being regulated by the adjustable nut 9 screwing onto the outer end of the shell or nut 6.

The nut 6 is preferably internally threaded to receive the corresponding threads of a screw shaft I0 which constitutes a main portion of the driving member whose other principal portion is an engaging head l I splined or otherwise xedly held to the shaft I0, and having angularly disposed jaws or teeth to engage corresponding A jaws or teeth on the sleeve I2 which connects with the power shaft of the engine; the member Il being frictionally held against rotation by ring clamping means Ila until such time as rotation of shell 6 is'imparted to the member I0 to overcome the drag of spring member l la. The inner end of the screw shaft is preferably provided with a stop nut I4.

As above stated, the nut 6 is formed as a shell to whose exterior one set of the clutch plates 1 is splined. 'Ihe rear end of shell 6 is provided with a marginal flange l1 bearing against the annular includes a rotatable gear member I8 which in turn'abuts the right-hand end of the clutch plates l.

Next describing the reduction gearing, the same I9 winch is mounted on shaft 2i having its bearings in the hub of the gear I9 and also in the socket formed in the enlarged end 65 of shaft 22. The gear I9 drives the planetary gearing including the series of planetary pinions, one of which is shown at 26, and also including the parallel plates 21 and 28 which form a frame for such pinions and are held in place by the studs 30 on bearings 29. The stationary ring gear 23 is secured to the casing I by suitable means including the pins 24. The means for irnparting the rotation of the planetary gears to the barrel preferably takes the form of a series of riveted members29.

The means for actuating the apparatus is here shown as an electric motor 3i whose armature shaft 22 is provided at its forward enlarged end 65 with a pinion 68 meshing with the gear 59, the latter being the driving means for pinion 39 and gear I9.

Describing a cycle of operation for the parts thus far enumerated, and assuming that the actuating means is the electric motor, when the motor is energized the shaft 22 will be rotated, thereby rotating the pinion 68, gear 59, pinion 39, gear I9 and the planetary gearing, and consequentlyrotating the driving barrel 5 to transmit torque through friction clutch i to the shell or nut 6. By reason of the rotation of this nut, the screw shaft or driving member IIJ, being held against rotation by members Il and i Ia,is automatically advanced longitudinally to the left, thereby projecting member Il into engagement with the engine member I2. When such longitudinal movement ceases, the torque of the motor will be transmitted through the mechanism described to the member I i, thereby overcoming the frictional resistance to rotation, and cranking the engine.

From the foregoing it will be observed that the engine has been initially cranked through the force of the driving power transmitted through the shaft 22 and the gearing shown at 68 and 59, such gearing being preferably designed to supply the necessary torque to overcome the initial maximum resistance to turning inherent in the member I2. Since the gearing just referred to is adapted to supply maximum torque, it is an object of the present invention to provide supplementary speed multiplying mechanism whereby the considerably lessened resistance to rotation which is offered by the member I 2 once the initial friction has been overcome, can be taken care of by a system plying such reduced torque at a considerably greater speed.

The present invention therefore discloses means for multiplying the speed and proportionately reducing the torque of the driving apparatus after the initial relatively great torque has been supplied at a considerably reduced speed through the initial driving connections above described. As shown herewith by way of illustration of the preferredl means for effectingtthis result, the means employed comprises a suitable motion transmitting member 40 adapted to rotate with the gear 59 at all times, and therefore adapted to transmit power thereto when it is itself drivably associated with the primary driving member 22, said member 4U constituting one principal member of a clutch mechanism whose other principal member is shown at 4i. Such of gears which will be capable of sup-v clutch mechanism may of course take any suitable form as will be obvious to persons skilled in the art, but as shown herewith by way of illustration, the mechanism preferably includes a driving jaw or plate having suitable teeth or other equivalent means 42 adapted to engage correspondingly disposed members 43 on the complementary driven member 40, the latter being rigidly secured to the shaft 44 by suitable key means such as that indicated at 45.

rl'he means preferably employed for normally maintaining driving member 4l out of engagement with the member 40, and the associated means for effecting. such engagement notwithstanding said preventing means comprises, as shown in Fig. 1 by way of illustration of the preferred arrangement, a spring or equivalent yielding member 45 having one end abutting the wall of housing i and having its central portion wound around a pin or other suitable pivot member 4l for rod 48, the opposite end of the spring 46.

being so formed as to operatively engage the lower portion of rod 5l as indicated at 49.

From the foregoing it will be evident that the member 45 is adapted to exert a force against the member 48 tending to hold said member in the position indicated in Fig. 1 in which position it is adapted to maintain the member 4l out of driving relation to the member 49. The means whereby the member 48 controls longitudinal movement of the member 4i preferably comprises an annular groove 50 adapted to receive the enlarged end of the member 5I in such manner that a rocking motion imparted, to the member 43 so as to cause it to rock upon its fixed pivot 41 will produce a corresponding longitudinal displacement of the member 4I to the left as viewed in Fig. 1 and therefore into driving engagement with the member 4U. At 52 is shown a member intended to indicate any suitable device for permitting the operator of the engine to control movement of the rod 48 from any convenient location.

From the foregoing it willl be apparent that means are provided for normally preventing a driving engagement between the members 4I and 49, therefore normally preventing the transmission of a driving force to gear I9 by way of gears 55 and 5B 'and shaft 54. It will be recalled however that the rotation of gear 68 during the transmission of the initial starting torque to the member I2 by means before described causes a rotation of gear 59, and hence of pinion 39 and gear I9, by virtue of the provision of the overrunning clutch member 66 which constitutes a positive driving connection between the bored end 65 of shaft 22 and the gear 68 (assuming clockwise rotation of member 65 as viewed in Fig. 2) so long as members 4I and 40 are out of engagement. This disengagement of the members 40 and 4I, which normally obtains, renders rotation of the members 40 and 53 an idle nonproductivey movement. That is to say, the end portion 53 of shaft 44 during the existing of the foregoing conditions, will rotate freely in the recess provided in the member 54 as shown. The member 54 will also rotate under the same conditions, its rotation being relative to the rotation imparted to the member 53 and at a different speed, rotation being imparted to the member 54 under such conditions by virtue of its connection with the gears 55 and 56, these gears being constantly in mesh, and the former being keyed to the enlarged portion 51 of shaft 22 by suitable means such as that indicated at 58.

From the foregoing it will be evident that the rotation of members 56 and 54 which is produced by the initial energization of the motor 3| will have no effect, from an operating standpoint, upon the speed or torque transmitted to the members and I2, such initial speed and torque being determined by the design and. relative arrangement of the members 68, 59, etc., together with the speed of rotation of the motor 3|. After such initial transmission of a relatively great torque at a relatively low speed, however, a considerably reduced torque (preferably just sufficient to maintain a force capable of overcoming the normal drag of the engine as distinguished from the much greater initial inertia thereof) and a considerably increased speed can be produced by operation of the auxiliary transmission mechanism under thecontrolof the operator of the engine by manipulation of the operators device represented in Fig. 1 at 52. Operation of the member 52 will causea longitudinal movement of the driving member 4| into engagement with the member 40 as above explained. When so engaged the rotation imparted to the member 4| through the connections56, 55 and 54 will cause a corresponding rotation of the member 40 and hence of the shaft 44 and pinion 39. The pinion 39 will in turn drive the shaft 2|, through the gear I9, in the direction corresponding to that in which it has theretofore been rotating, but at a considerably increased speed by virtue of the increased ratio produced by the substitution of the gears 55 and 56 in the transmission train in lieu of the gear 88.

With the increased rotative speed which is thus imparted to the member 2 (with which the member has already effected engagement) the 'power shaft of the engine will be rotated at a speed which will assure a firing of the explosive charge and hence the starting' of the engine under its own power. When so started the driving member will be withdrawn by reason of the inclined formation ofthe jaws as shown.

The means whereby the initial transmission mechanism is rendered ineffective in part upon -the introduction of the auxiliary transmission mechanism, will "now be further explained. It has been stated that upon engagement of the members 4| and 40 the gear 68 is automatically eliminated from the gear train, so far as being an active force transmitting member is concerned. The gear 68 is not actually disconnected from the gear train; in fact it remains in mesh with the gear 59. Notwithstanding this continued engagement, however, the member 68 becomes inelTective although continuing to rotate. Such ineffectiveness results from the fact that there exists an increased gear ratio between gears 55 and 56 as compared with the gears 68 and 59. This greater ratio produces a rotation of the gear 59 at a speed which is a multiple of its former speed. As a result the gear 68 is caused to rotate at a speed greater than the speed of rotation of the member 65. As a result of .this differential action the gear 68 becomes in effect the driving member with respect to the member 65. In consequence of this fact the clutch members 66 are held substantially in the positions shown in Fig. 2, in which positions they do not interfere with a rotation of the gear 68 at a speed substantially "greater than the speed of rotation of the shaft 22 and hence of the member 65.

By reason of the construction just explained the gear 68 is rendered ineffective as a driving.

member with respect to the gear 59, and becomes instead a, driven member rotating at a speed greater-than that of the shaft 22. Furthermore as has been made clear, the construction is such that the rotation of the members 22 and 68 at different speeds under such conditions is permitted.

It will be understood of course that upon the starting of theengine under its own power the operator relieves the pressure on the member 52 thereby permitting the driving member 4| to be withdrawn from engagement with the member 40 by action of the spring 46.

From the foregoing it will be seen that the invention provides for the operator of the engine supplementary means for securing a successful cranking of the engine in the event that the initial driving mechanism proves unsuccessful because of the lower speed thereof. By this additional means the starting of the engine on its own power is assured even in cases where starting is extremely dicult. as for example where the ignition system is of such design that a firing spark cannot be obtained except by turning the engine over at a speed at which the usual starter is incapable of taking hold because of the deceased turning power which results from the use of such high rotative speeds. It is in such diflculties as this that the present invention is-of great importance, in that it provides means for first taking hold on the engine member |2 by a strong but relatively slow engaging force, and then provides further means for bringing the member I2 up to a more suitable cylinder firing speed.

It is to be understood, however, that the mechanism of the present invention is of great utility even in cases where such dimculties as that just referred to, do not exist. In fact, the economy in current consumption resulting from the use of a slow speed during starting of the motor, is an important advantage rendering the mechanism one of great utility in all cases. Of course, the operator could, (if he chooses) actuate the member 52 in the first instance, and thus produce immediate actuation of the motor and starting mechanism at the higher speed, so long as the conditions are such that the decreased torque at the higher speed is nevertheless suflicient to crank the engine. However, such operation will not normally be employed, if for no other reason than that it fails to take advantage of the means for effecting economy in current consumption.

It will be further evident from the foregoing that the present invention has the additional merit of simplicity, accessibility of the component parts, economy in arrangement and space consumption and the use of a structure wherein the necessity of shifting gears from meshing to unmeshing positions is avoided.

While only one embodiment of the invention has been illustrated and described herein, it is to be understood that the invention may be incorporated in numerous other structures di'ering in form and in the method of arrangingand actuating the component parts thereof. Like- Wise other changes, which will now appear to those skilled in the art, may be made in the form, details of construction and arrangement of the parts, without departing from the scope of the invention; and reference is therefore to be had to the appended claims the limits of the invention.

What is claimed is:

1. 'I'he combination with a rotatable member of an internal combustion engine, of a substanfor a definition of tially constant speed motor, means responsive to energization of said motor to produce immediate operative connection between said motor and engine member whereby the latter is caused to rotate at any selected one of a plurality of substantially constant speeds bearing a constant ratio to the speed at .which said motor operates, and means for preventing any change in said constant ratio during the cranking operation except by manual intervention.

2. The combination with a rotatable member of an internal combustion engine, of a substantially constant speed motor, means responsive to energization of said motor to produce immediate operative connection between said motor and engine member whereby the latter is caused to rotate at any selected one of a plurality of substantially constant speeds bearing a constant ratio to the speed at which said motor operates, and manually operable means permanently positioned in the mechanism for selecting the ratio to be employed, said selection being possible either prior to the beginning of the cranking constant -rato during operation or at any stage between the beginning and the completion thereof.

3. The method of imparting initial rotation to a rotatable member ofv an internal combustion engine, by the use of asubstantially constant speed motor, which includes the step of causing the energization of said motor to produce immediate operative connection between said motor and engine member whereby the latter is caused to rotate at a selected one oi a plurality of substantially constant speeds bearing a constant ratio to the speed at which said motor operates, the constancy of said ratio being maintained vby preventing anychange in said the cranking operation except by manual intervention, and finally the step of increasing the speed of rotation of said engine member by a definite predetermined amount, said increase being brought about by manual intervention after the initial'resistance to movement has been overcome by reason of the preliminary rotation at relatively low speed.

' ROMEO M. NARDONE.

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