US2295289A - Engine starting mechanism - Google Patents

Description

Sept. 8, 1942. R. M. NARDONE ENGINE STARTING MECHANISM 3 Sheets-Sheet 1 Filed ApriI'B, 1941 Sept. 8, 1942. R. M. NARDONE ENGINE STARTING MECHANISM 3 Sheets-Sheet 2 Filed April 8, 1941 INVENTOR ROIIIeOM lVm-dolze. BY I NEY ATT Sept. 8, 1942.

R. M. NARDONE ENGINE STARTING MECHANISM Filed April 8. 1941 3 Sheets-Sheet 3 "IIHIIIIIIL INVENTOR Talented Sept. 8, 1942 2,295,289 ENGINE s'raa'rmc MECHANISM Romeo M. Nardone wcstwood, N. J., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware ApplicatlonApril 8, 1941, Serial No. 387,540 3 Claims. (Cl. 290- 38) This invention relates to internal combustion engines, and particularly to the starting of an internal combustion engine by imparting initial rotary movement to the engine crank-shaft through the agency of a mechanical torque transmitting starter mechanism.

An object of the invention is to provide an engine starter that can be readily adapted for rotation in a direction opposite to that originally prevailing, thus facilitating its application to an engine other than the one originally associated therewith.

Another object is to provide novel means for moving an engine-engaging member to engineengaging position, following initial storage of energy in a driving member of the inertia type.

Another object is to provide novel means facilitating rotation of the inertia element (flywheel) in either desired direction, prior tooperation of the means for moving the engine-engaging member to engine-engaging position.

Another object is to provide flywheel energizing means including a reversible electric motor having associated therewith brush lifting and reversing mechanisms of novel construction. A

These and other objects of the invention will become apparent from inspection of the following specification when read with reference to the accompanying drawings wherein is illustratedthe preferred embodiment of the invention. 1 It is to be expressly understood, however, that the drawings are for the purpose of illustration only, and are not designed as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

In the drawings,

Fig. 1 is a longitudinal sectional view of a device embodying the invention;

Fig. 2 is a view along line 22 of Fig. 1;

Figs. 3 and 4 show the engine-engaging member and actuating means therefor, in, successive stages of operation;

Fig. 5 is a view along line 56 of Fig. l; and

Fig; 6 is a diagram of electrical connections.

In Fig. l the inertia element ll (flywheel) is shown as having a hub I2 keyed to the shaft ii of the armature ll of an electric motor whose field coils 16 are supported on a frame I! fastened to a transverse plate It constituting part of a sectional housing; the said plate It being secured between the housing sections 2| and 22.

A third housing section 23 supports the sections 22 and 2I', and is in turn supported on a mounting flange 24 of the engine to be started; the sections 23 and 24 being held together by suitable bolts 28. A rotatable part 21 of the engine has ratchet teeth 28 for engagement by correspondingly shaped teeth on an engine-engaging member 29, and the latter has a cylindrical extension or hub 3| mounted for rotation and limited axial movement within the housing section Housing section 22 has an inwardly extending position with two openings-one to receive a bearing assembly 38 in which the shaft l3 ro tates, and the other to receive *a pair of bearing assemblies 31 and 38 in which a shaft 39 and a sleeve til have unitary rotation. Sleeve I0 is an extension of a bell-shaped gear Ii which meshes with a pinion 42, the latter being integrated with armature shaft l3v in any suitable manner.

Shaft 39 is keyed to sleeve 40 and terminates in teeth 44 to form a pinion having meshing relationship to the internally formed teeth of an i annulus gear 45 whose hub 41 has relative rotation about a hollow shaft 48 that is drivably connected to the hub of a plate 49 constituting part of a barrel 5|. Bearing assemblies 52 and 53 facilitate free rotation of barrel Si in housing section 23.

Hub 41 of gear 46 has teeth, and these constitute a sun gear for mesh with a plurality of planetary gears 56 that are rotatably mounted on the barrel end 49 and mesh-with an internal gear 51 which is shown as integral with the housing section 23. Preferably three planetary gears 56 are employed, and one of these is shown in section in Fig. 1. These gears 55 are preferably spaced l20 apart, so that as the view is taken in Fig. Lone of the gears appears in elevation below the center line. Each of the plane tary gears is rotatably'mounted by means of a ball bearing 58 carried by a sleeve 59 which is held at its inner end in barrel end 49. Extending into sleeve 59, and threaded thereto is a screw 6| which supports the sleeve, bearing and planetary gear. If desired a retaining ring 62 for bearings 58 may be formed integral with sleeves 59. m

For torque limiting purposes there is preferably employed a multiple disk clutch embodying a plurality of friction disks 63, a number of said disks bein splined to the inner surface of barrel 5|, and the remainder being splined to the outer surface of a shell or sleeve 64. Resilient means such as a plurality of coil springs 66 and an adjusting nut Bl, which is threaded into the inner end of barrel 5|, are provided for varying the pressure with which.disks 63 are maintained in engagement.

The" novel engine-engaging control means, heretofore referred to, will now. be described in detail. A rod 8i passes through hollow shaft 48,

and at its outer end is threaded to receive a nut tains the said member 29 in assembled relationship to the rod 8! which passes freely through said apertured wall 83. At its other end rod 81 is formed to receive one end of a bell-crank 24 mounted on arock-shaft I4 iournaled in bearings 81 and 88 (Fig. 2) oi the housing section 22, and projecting through said housing section 22 to receive a second bell-crank 99 for manual operation 01 rod 8|. Automatic operation of rod II, following initial acceleration of flywheel II, is provided by solenoid 9| whose plunger 92 has an extension 93 which abuts the upper end bellcrank 84 and moves the latter about its pivot in response to energization of winding 9| in the manner hereinafter described. A torsion spring 94 yieldably opposes such clockwise (Fig. 1) swinging of bell-crank 94, but this clockwise swinging is nevertheless eii'ective to move rod I to the left. On the rod ll there is a coiled compression spring 96 and a cup 81, the latter being normally urged against the rod collar 99 by the spring action. A detent III is urged in a radially outward direction by a leaf sprin I 62, and, because of this urging, it normally engages a tapered shoulder I 03 (Figs. 1, 3 and 4) formed by the internal splines of sleeve 64, which splines coact with the external splines I95 on the hub ll of engine-engaging member 29. This engagement of detent IIII with shoulder I09 holds member 29 against any axial displacement until the axial displacement of rod ll fully compresses spring 96-in other words, until the parts reach the relative positions shown in Fig. 3. At that moment the continued pressure to the left of rod collar 8| (urged by the solenoid plunger 92), in conjunction with the now built-up stress in spring 96, results in a snap-action movement of member 29 to the left, into the position shown in Fig. 4. Thus engine engagement is eflected, and the energy previously stored in flywheel II is transmitted to the member 21 of the engine, to crank" the latter.

The previous storage of energy in flywheel ll may have been by manual acceleration of the flywheel (through the gear train) or by motor operation. Motor operation involves an automatic brush applying action by electromagnetic control means now to be described.

Brush actuating solenoid I91 has a plunger Ill connected by means of springs"! to clevis arms I II which are loosely joined to brushes H2 and H3. Operation of the solenoid causes pltmger I08 to move down (as shown on the drawing) so as to extend springs I09 and pull arms III down to apply pressure on top of the brushes 2, III. The act of lowering the brushes to the commutator acts as a switch so that the motor is immediately energized and accelerates flywheel II. When solenoid I01 is de-energized, the spring I II acts to push the plunger Ill upward, and collar I4 contacts arms III to rotate them about their hinge points I I! and lift the brushes 0!! the commutator by reason of the inter-engagement oi said arms with the slots in the brush-carriers I2I.

The rotation 'of the motor can be reversed merely by shifting the live lead I22 from terminal I I23 to terminal I24, at the same time Joining up brush H2 toterminal I28. Brush 2 isshown as connected to terminal I24. This reversal involves only a simple shift of conducting anglestrip I21 from one terminal to the other.

To control the flow oicurrent from source I2 to the motor and solenoids II and ll I employ a switch having a movable element with portions I and I42 of insulating material, and portions I42 and I44 of conducting material; also stationary fingers I46, I41, I49, and I49. A handle I" enables the operator to close, first, the switch I48, I49, I41 to energize the solenoid III! and thus apply the brushes to the motor. This allows current to flow through both the field coils I4 and armature I4 of the motor, in series, and the flywheel I I is thus energized at high speed.

When suflicient energy has thus been stored. theoperator pushes handle I50 further to the left, thus adding to the original circuit a second circuit passing to the solenoid 9i by way of contacts I44, I44, and I49. The member 29 is thereupon snapped into engine-engaging position (as heretofore explained) and the engine cranked.

When the engine starts, the operator returns switch I50 to the dead position (Fig. 6), and springs III and 94 now come into eflect; spring III, to lift the brushes from the commutator (Fig. 6); and spring 94, to restore rod 8| to its normal (Fig. 1) position, and-along with it-the member 29.

What is claimed is:

1. In an inertia starter, the combination with flywheel and engine-engaging member, of means including a reversible electric motor for accelerating said flywheel, said motor having a fleld winding and commutator-engaging brushes and means normally holding said brushes in non-engaging position, electromagnetic means for moving said brushes to engaging position, a source of current for the motor, means for sending current through the motor fleld winding in either direction in response to operation of said electromagnetic means, said last-named means including an angle-piece connecting one fleld winding terminal with one of said brushes, and means for attaching said angle-piece to the other oi said field-winding terminals when rotation of the motor in the opposite direction is desired.

-2. In an inertia starter, the combination with a flywheel and engine-engaging member, of means including a reversible electric motor for accelerating said flywheel, said motor having a fleld winding and commutator-engaging brushes, a source of current for the motor, means for sending current through the motor fleld winding in either direction, said last-named means in-, cluding a bridging element connecting one fleld winding terminal with one oi! said brushes, and means for attaching said bridging element to the other oi. said fleld-winding terminals when rotation oi the motor in the opposite direction is'de- '3. In an inertia starter, the combination with a flywheel and engine-engaging member, oi means including a reversible electric motor for accelerating said flywheel, said motor having current receiving terminals, a fleld winding and commutator-engaging brushes, a source of current iorthe motor, means for sending current through the motor in either direction, said lastnamed means including an angle-piece connecting one motor terminal with one of said brushes, and means for attaching said angle-piece to another of said motor terminals when rotation of the motor in the opposite direction is desired.

ROMEO M. NARDONE.

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