US2249393A - Engine starter - Google Patents

Description

July 15, 1941. R. M. NARDoNE 2,249,393

' ENGINE STARTERA Original Filed June ll, 1937 5 Sheets-Sheet l RM@ TM Ze. ma.- ,11% WW? In.. I. .M

July l5', 1.941 R. M. NARDONE ENGINE STARTER l Original Filed June 1l, 1937 3 Sheets-Sheet 2 "m1 www l INVENTOR.

July 15, 1941.

' R. M. NARDoNE ENGINE STARTER 3V Sheets-Sheet 3 Original Filed June 1l, 1937 INVENTORL Romeo M Nardo/7e tm WZ RNE Patented `uly 15, 1941 y UNITED ls'nrll;as PATENT .OFFICE Romeo M. Nardone, East Orange, N. J., assigner to Eclipse Aviation Corporation, East Orange,

N. J., a, corporation of New Jersey original application June 11, 1937, vserial No.

147,768;- Dividedand this application Novemlber 21, 1939, Serial No. 305,543

o claims; (c1. 12s-179') This invention rel-ates'to vstarters forvinternal combustionV engines, and -more particularly to starters of the'electric inertia type.

This application is a division of my tion No. 147,768 led June 11, 1937.

One of the objects of the present invention is to provider a novel engine starter which is Aparticularly adapted Vfor use in cranking -1arge highcompressionl engines such as are in present use on high-powered trucks and buses.l M

Another -object is to provide an engine starter employing novel means for'transmitting the en`` ergy stored in a high speed flywheel to a inemberof an engine to be started. l e f' Another object is `to'provide a novelV method of operation of an engine starter of the type including a flywheel, which novel method involves the concept of nullifying, or-at leastreducing, thedrift tendency of the engine engaging member by applying a retarding force to the flywheel and-thereby consuming the unexpended portion of the energy previously stored therein.

-v Arfurther object is to provide a novel ydriving unit for drivably connecting an engine starter to a member of an engine to be started. y

Other objects include-the provision of novel means for interrupting orf-preventing the transmission of torqueduring the energy storing interval, and novel -means for quickly stopping the high vrspeed flywheel after the engine Ahas been started. Y y

The. aboveand further objects and `novel features of this invention will more fully appear from the following detailed description vwhen taken in connection with the accompanying drawings. It is to be expressly understood, lhowever, that the drawings are for 4the purpose of illustration only and are not designed as a dennition of thelimits of the invention, reference being had primarily for this purpose to'the apapplica'- pended claims.

In the drawings wherein like reference characters refer to like parts throughout the several views:

Fig. 1 is a longitudinal section .of a starter embodying the present invention;

Fig. 2 is a transverse sectional View taken substantially on line 2-2 of Fig. 1;

Fig. 3 is a view of the brake and brake applyingsolenoid;

Fig. 4 is a view vof the friction clutch actuating solenoid; and Y- Fig. 5 is a diagrammatic View of the `electrical controlof the driving motor and the 'solenoids just referred to. y

The embodiment ofthe invention illustrated in Figs. 1 and-2 comprises-a housing 6 having a pair of end cover plates Tand-8. motor 9 isv mounted in the outer end of housing 6 and is provided with a hollow shaft `I0 upon which are mounted the motor Y'arm-aturefll and an inertia flywheel t2, the latter being drivablyV connected' thereto bya'ni'r suitable means such as a key lia.

In order t'o reduce the overall length of the starter,*reduction gearing and Aoverload resisting means for such gearing are mounted within the overhanging rim of flywheel I2. As shown, the reduction gearing-is constituted by a ,plurality of planetary gear Amembers I4, preferably three, spaced at degree intervals, rotatably mounted on stub shafts I5 that are-supported by a ring I6 which is rotatably mounted on shaft Iby means such as a ball bearing II. Gears I4 mesh with a pinion I8 splined to shaft I6, and with an internal gear I9 which is rotatably mounted on the inner end of shaft ID by means such as ball bearing 20.

Preferably, overload releasing means in the form of a friction disc clutch are provided to protect the above gearing and other elements of the starter from damage due to sudden shocks and overloads imparted thereto. As shown, this riphery of ring I6 and Valternate with the other half of said discs which are splined to the inner periphery of cylindrical member 22 that'is held in operative position by means of an outwardly extending ange 24 secured as by means of bolts between housing 6 and cover plate 8.

The 'discs 2l are positioned between an internal flange 21 on member 22 and an annular series of coil springs 25 which bear at their outer ends against the bottom of a flanged cup-shapedadjusting member 26 threaded onto the cylindrical portion of member 22, thereby the slippage load of the clutch discs 2l may be adjusted. For adjusting cylinder 26 and hence the tension of springs r25, saidcylinder is provided on its .inner end with a notched flange accessible through a hand hole '28 in housing 6. A clip 29 removably secured to cylinder 22 is provided for engagementwith a suitable notch in the ange of mem-. ber 26 whereby the latter may be locked in ad; justed position. In cranking engines of the character referred to above, it is desirable to establish the engagement 'of the starter with the ywheel gear of the engine. If such a drive be permanently connect- An electric ternal gear I9 by means of bolts or rivets 32 andY adapted to be frictionally engaged onits inner periphery by a pair of arcuate shoes 33 (Fig. 2).

The friction shoes 33 are drivably connected to a shaft 34 which is rotatably supported at its outer end by a bearing 8a. mounted centrally ofr V,

cover plate 8 and at its inner end by a bearing 36a. mounted in a bracket 36 formed integralv with a supporting spider 31.. The latter is adapted to be attached to the crankcaseof an engine as by bolts 36h and the starterA is in turn secured to the spider as by means of bolts 31a. As illustrated, shoes 33 are mounted on a sleeve 38 splined, yor otherwise drivably connected, to a shaft 34 in the plane of bearing 8a. Sleeve 38 is provided with a pair of laterally extending, diametrically disposed ears 38a which carry bolts 39 on which shoes 33 are pivotally mounted and retained as by means of nuts 39a. The pivots of shoes 33 are thus offset from the center of rotation of drum 3|. I

Novel means are provided for moving shoes 33 into engagement with drum 3| and such means, as illustrated, -comprise a rod 40 slidably mounted within hollow armature shaft I0. Said rod is adapted to be actuated by a lever 4I which operatively engages the outer end thereof and is pivoted on a bracket 42 suitably attached to cover plate 1. The inner end of rod 40 has a conical portion 40a adapted to engage beveled portions 4Gb of the webs of shoes 33 at a point midway between pivots 39 and is effective, when moved to the right as viewed in Fig. l, to impart Ito said shoes a camming action whereby the latterare moved into engagement with drum 3|. Suitable springs 43 are attached to a portion of the web near the pivot of each shoe and to the free end of the other shoe thereby tending to hold said shoes out of engagement with drum 3|. It will be noted that the above-described clutch is of the self-energizing type and during clockwise rotation :of drum 3| and after shoes 33 have been moved by means of rod 40 into enl gagement with the drum, the latter tends to move shoes 33 into closer frictional relationship.

A novel drive unit is provided for automatically connecting the mechanism described above to a member of an engine on which said starter is mounted and, as shown, such unit consists of an internally threaded sleeve 44 adapted to be mounted on a lthreaded portion of shaft 34 for rotary and longitudinal movement thereon. Splined to sleeve 44 for longitudinal movement relative thereto and rotary movement therewith is a pinion 45. For yieldingly resisting relative longitudinal movement between said sleeve and pinion, a coil spring 46 is interposed between an outwardly extending shoulder on the former and an inwardly extending `shoulder on the latter. A splitring 41 is received within a peripheral groove in sleeve 44 for engagement with a suitable shoulder on the pinion to limit .the relative longitudinal movement of said pinion to the right. When shaft 34 is rotated, sleeve 44 and pinion 45 resist rotation, due to their inertia, and are thereby caused .to move longitudinally to the right on shaft 34, and into driving engagement with the engine flywheel gear 48. To prevent movement of sleeve 44 and pinion 45 along shaft 34 into engagement with gear 48 when the starter is not in use, a light anti-drift spring 49 is interposed between said sleeve and a stop nut 59 secured to shaft 34 adjacent the outer bearing 36a therefor.

As a supplement to the anti-drift spring 49 I provide an energy dissipating means for positively eliminating the condition which tends to reduce the objectional drift of the pinion 45 toward a. re-meshing position, after it has once been retracted by the over-running action hereinafter referred to. As shown in Fig. 3, this energy dissipating means comprises a brake shoe 89 vadapted to frictionally eng-age the periphery of flywheel I2 or |2w through a suitable opening in housing 6. The outer end of shoe 89 is operatively attached to the forked end of a right angle lever 99 pivoted at its lower end to housing 6.

Electro-magnetic means are preferablyY provided for rocking lever 9|).about its pivot, whereby shoe 89 may be lifted out of engagement with ywheel I2 or I2a. A magnet 9| is shown mounted on housing 6 by Vmeans of bracket 92y and is provided with a plunger or core 93. The latter is fastened to, and adapted to actuatea rod 94 which is suitably attached at one end to lever 9U for operating brake shoe 89. Y Coil 9| is also provided with aV stationary soft iron core 95 which extends substantially one-half the length of the coil and is eiective to attract plunger 93 when said coil is energized. The other end of rod 94 slidably extends through core 95 and may have mounted thereon a contact arm 96 adapted to bridge a pair of contacts 91, 98 for closing a circuit to motor 9 or 9a; but the preferred method is to employ a separate solenoid, as shown at 'I2 in Fig. 5, to control closure of the motor circuit, as will be more fully described.

Electromagnetic means are also provided for effecting the driving engagement of the members of the self-energizing clutch shown in Fig. 2. One form of such means is shown in Fig. 4 and comprises an electromagnetic unit substantially the same as those described above for actuating the brake shoe 89 and the motor control switch 96. Lever 4I, above referred to, connects at its lower end with a plunger 94 of a solenoid 9|. Thus, when coil 9|' is energized, plunger 94', attached to core 93', moves to the left to swing lever 4| in a clockwise direction, thereby moving rod 40 to the right. The movement of the latter to the right is effective, as explained above, to complete fthe line of torque transmission from the starter motor and flywheel to the driving unit 44, 45.

As shown best in Fig. 5, a common electrical control is provided for all four electromagnetic units-motor 9, coil 12, coil 9| and coil 9|' A cycle of operation is as follows: Beginning with the parts in their'normal positions as shown in Figs. 1 and 5, the common control switch I|2 is moved downwardly from the neutral position shown in Fig. 5 whereupon two conditions are brought about. First, there is an -energization of solenoid 12 by current taken from'the battery |03 by way of conductors |99, |04 and |05, the return circuit being by Way of conductors '|06 and contact plate -YIU'I of the Vcontrol switch II2. The resulting bridging of contacts 9T establishes a circuit to energize the motor 9 by current kdrawn from the same source ID3, as shown.

Simultaneously with this action, there is the closure of a circuit to the brake releasing solenoid BI by way of conductors I and I08 and the conducting plate |09 of the control switch II2, the plates IBS and III'I moving in unison to the circuit closing positions. The brake 89 being thus released, and the motor 9 being energized, shaft I0 and flywheel I2 are rotated.

When sufficient energy has been built up in flywheel I2, the control switch H2 is shifted to its upper position, thereby bringing conducting plate I I3 into position to close a circuit to the solenoid SI while at the same time bringing conducting plate II4 into position to maintain the brake releasing solenoid BI energized. Energization of solenoid BI causes the lower end of lever 4I to be moved to the left, thus moving rod 4i! to the right and shoes 33 radially into driving engagement with drum 3| whereby shaft 34 is rotated. Upon the initial rotation of shaft 34, the inertia of driving unit 44, 45 causes said unit to move longitudinally on shaft 34, compressing spring 49, whereby pinion 45 meshes with flywheel gear 48 and engages stop nut 5U. The driving unit now rotates with shaft 34 and the engine is cranked.

When the engine starts, flywheel gear 48 will drive pinion 45 and this overrunning action will return the driving unit to the demeshed position shown in Fig. 1. Thereupon the operator allows switch I I2 to return to the neutral position indicated in Fig. 5, thereby deenergizing the solenoid 9| and permitting the brake shoe 89 to take hold upon the flywheel I2 under the urge of spring 99, The resultant stoppage of the flywheel and the gears and other parts rotated thereby, including the screw shaft 34, eliminates any tendency which the thread of the screw shaft might otherwise have to induce a re-drft of the pinion 45 into objectionable contact with the now rapidly rotating teeth of the gear 48. Thus the application of the brake 89 serves as a supplement to the spring 49 in reducing any such re-drifting tendency on the part of the pinion 45.

The self-energizing clutch 33, 34 tends to form a positive driving connection between the flyr wheel and the pinion 45, but the various elements of the starter are protected from overload by the preset clutch 2 I, 22, 26, which may be accurately adjusted to transmit a desired amount of torque.

What I claim is:

l. In a device of the character described, in combination, a driving drum, a driven shaft, said driven shaft having a flange located within said driving drum, means including friction shoes piv- Aotally mounted on said flange for radial movement into engagement with the inner surface of said drum, electromagnetic means for producing radial movement of said shoes into engagement with said drum, means for producing rotation of said drum independently of energization of said shoe moving means, said last named means including an electric motor, and means for producing successive feeding of current to said motor and said electromagnetic means.

2. In a device of the character described, in combination, a driving drum, a driven member, means including friction shoes pivotally mounted on said driven member for radial movement into engagement with said drum, electromagnetic means for producing radial movement of said shoesintoengagementwitlr said drum, means for producing rotation ofsaid` drum independently of energization of said shoe-moving means, said last named -means including an electric motor, and means for producing successive feeding of current to' said motor and said electromagnetic means. -1 l 3. In an electric starter vwherein a flywheel is energizable by acceleration thereof to a relatively high speed and wherein the energy of said flywheel is adapted to be transmitted through an engine engaging member to a member of an engine to be started, the combination with said engine engaging member and iiywheel of means for engaging and disengaging said engine engag- A ing member, said means tending .to produce a re-drift of said member into the engine engaging position, braking means engageable with said flywheel to reduce said re-drift tendency, electromagnetic means for holding said braking means out of contact with said flywheel during acceleration of the flywheel and application of cranking energy to said engine member, an electric motor for accelerating said flywheel, a clutch interposed between said flywheel and. engine engaging mlember, electromagnetic means for controlling said motor, electromagnetic means forcontrolling said clutch, and a common control for all three electromagnetic means above recited.

4. In an electric starter wherein a flywheel is energizable by acceleration thereof to a relatively high speed and wherein the energy of said ywheel is adapted to be transmitted through an engine engaging member to a member of an engine to be started, the combination with said engine engaging member and flywheel of means for engaging and dsengaging said engine engaging member, said means tending to produce a re-drift of said member into the engine engaging position, means to reduce said re-drift tendency, electromagnetic means for preventing operation of said last named means during acceleration of the flywheel and application of cranking energy to said engine member, an electric motor for accelerating said flywheel, a clutch interposed between said flywheel and engine engaging member, electromagnetic means for controlling said motor, electromagnetic means for controlling said clutch, and a common control for all three electromagnetic means above recited.

5. In an electric starter wherein a flywheel is energizable by acceleration thereof to a relaan engine engaging member to a member of an engine to be started, the combination with said engine engaging member and flywheel of means for engaging and disengaging said engine en-l gaging member, said means tending to produce a re-drift of said member into the engine engaging position, braking means engageable with said flywheel to reduce said re-drift tendency, means for accelerating said flywheel, and electromagnetic means for holding said braking means out of contact with said flywheel during operation of said accelerating means.

6. In an electric starter wherein a flywheel is energizable by acceleration thereof to a relatively high speed and wherein the energy of said flywheel is adapted to be transmitted through an engine engaging member to a member of lan engine to be started, the combination with said engine engaging member and flywheel of means said motor, electro-magnetic means for holding said braking means out of contact with said fly- Wheel Vvduring energization of said motor, and common control means for both said electromagnetic means.

ROMEO M. NARDONE.

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