US2560812A - Starter - Google Patents

Description

R. M. NARDONE July 17, 1951 STARTER 5 Sheets-Sheet 1 Filed April 1, 1946 C3 ?g m l NV E N TOR. Ra/1100M jviu'done ATTORNEYS,

July 17, 1951 R. M. NARDONE STARTER 5 Sheets-Sheet 2 Filed April 1, 1.946

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y 1951 R. M. NARDONE 2,560,812

STARTER Filed April 1, 1946 5 Sheets-Sheet 4 INVENTOR.

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STARTER Filed p l 1 19 6 5 Sheets-Sheet 5 Bra/6 11:5071

P011100 M uyd'ome MILLS f1 ZZUTrwZS,

Patented July 17, 1951 UNITED STATES PATENT OFFICE STARTER Romeo M. Nardone, Teaneck, N. J., assignor to Joseph J Mascuch, Millburn, N. J.

Claims.

This invention relates to direct cranking electric starters such as are used on internal combustion engines iii-aircraft, and other installations. Some features of the invention, however, may be readily applied to other purposes.

An object of this invention is to provide a starter having an extremely high power to weight ratio.

Another object of this invention is to provide a starter which can not engage with the running engine, and thereby become damaged.

A further object of this invention is to provide a starter which may readily be inserted or removed from its housing, thereby permitting of easy access to all of its moving parts.

A feature of this starter is its one-piece metal housing construction which insures concentricity of its rotating parts.

Another feature of this starter is the novel construction of the friction spring which eliminates the necessity for a plurality of coil springs with a consequent saving in space and weight.

An object of this invention is to provide a brush box assembly in which any single brush or brush insulator may be removed without disturbing the others.

A feature of this invention is a quick disconnect means by which the baflle plate is joined to the mounting flange by a cam lock.

A further feature of this invention is the novel construction of the spline nut whereby the jaw is advanced into position.

A final feature of this invention is the novel oil seal provided around the jaw shaft to prevent the entry of foreign matter into the starter mechanism.

The invention consists of the construction, combination and arrangement of parts, as herein described, illustrated and claimed.

In the accompanying drawings, forming part hereof, is illustrated one form of embodiment of the invention, in which drawings similar reference characters designate corresponding parts, and in which:

Figure 1 is a sectional view of the drive mechanism of the starter with some of the parts shown in elevation.

Figure 2 is a sectional view of the starter motor with some of the parts shown in elevation.

Figure 3 is a section taken on line 3-3 of Figure 1.

Figure 4 is a sectional view of the baflie plate assembly.

Figure 5 is a side elevation of the friction spring.

Figure 6 is an elevation, partially cut away, of the wave spring.

Figure '7 is a longitudinal section of the screw shaft.

Figure 8 is a sectional view of the camlock.

Figure 9 is a section taken on line 9-9 of Figure 2.

Figure 10 is a plan view of the brush spring holder.

Figure 11 is a side elevation of the brush spring holder.

Figure 12 is a side elevation of a spline nut, partly cut away, in accordance with the present invention.

Figure 13 is a side elevation of the helically toothed gear, partially broken away, as shown in Figure '7.

Figure 14 is an end view of Figure 12, looking in the direction indicated by the arrow [4 in Figure 12.

, Referring to the drawings, and particularly to Figure 2, I5 indicates a yoke to which a cover plate [6 is attached by screws l1. Four separate brush box insulators l8 are riveted to the cover plate 16.

The construction of the four brush box 1nsulators I8 is best shown in Figure 9 in which can be seen their location on the cover plate l6. Brush boxes I9 and brush rests 20 are rigidly secured to the insulator blocks 18. A terminal post 2| is located between two of the brush box insulators l8 and projects through both sides of the cover plate I6.

Four brush spring assemblies 22 of a construction best shown in Figures 2, 10 and 11, are inserted in rectangular openings 23 in the yoke l5. Each brush spring assembly 22 comprises a holder 24, in which is carried a freely slidable cup member 25 into which the coil spring 26 is inserted. The closed end of the cup member 25 presses against the top of the brush and the coil spring 26 forces the said brush against the commutator 21. Rearward motion of the coil spring 26 is prevented by an insulating washer 28 pressed into the open end of the holder 24. The dielectric holder 24 is provided with shoulders 29 so constructed that once the spring assembly has been inserted in the rectangular yoke opening 23 a slight rotation of its position causes the shoulders 29 to seat themselves upon the inside of the yoke l5. This construction provides a means for readily inserting or removing any brush without disturbing the others.

The yokes four larger rectangular openings 23 provide easy access to the brushes over which they are located. A spring steel band 38 is snapped over the yoke [5 to cover the openings 23 and is secured by means of tie wires.

The cover plate l6 (Figure 2) is centrally bored 31 to receive a ball bearing '52 upon which the commutator end 27 of the armature 33 is supported. A nut 34 attached to a hub 35 on the plate 55 holds the bearing 32 in place. The armature .83'is secured :to the: central shaft 351' by means'of' a screw Wlocked to it;

Four field coils 36 connected in series-parallel are held to the pole shoes 31 which are secured to the yoke 55 by means of fiat head screws. terminals soldered to the ends of the coils are connected, one to the innerextension' 'ofthe-tor minal post 2! and the other to a positive brushbox 38.

The forward end of the armature shaft'39 (shown in Figure 1) is hollowed and internally lii scarries-thetwmfirst stage planet gears Mi -on:

The gears mesh with. aista-- ball bearings 97. tionary internat gear .48: Lhis internal gear 48 is zmachined into the-borewofathe steel shell 49'- of the starter. v

The-first stage I spider Me-hasa' sunipinion 59 integral therewith and ,the-.-whole' rotates upona bronze shaft 5! which maintains the spider .48

ins axial: alignment.

The sun pinion. 58.-- engages-"with two second: stage planet gears-=52 'which are-.mounted upon roller bearings 53- on aasecond. stage spidenfik The second stage planet gears 52 also mesh with the internal gear 8820fthe shell 49.. This spider 5&"31150 has its sun pinion-55 which ridesupon. the bronze shaft 51..

The second. stage suni pinion 55.drives..the-four planet gears 5B which are: mounted on needle bearings 51 fi-xed to hardened studs onthe starter barrel v58.

The spiders 96, 54 rotate-freelyon the shaft-.51

but arc-l heldrin position bywashers=59f 60 and alock ring 8! snappedinn-a grooveat the end.v A- nut 82-holds the shaft 51' to.

of-the -shaft 5t. the barrel--58 and increasessi ts axial stability. Lock washersfit are provided to maintain the nut 82 in place.-

The: gear train comprising-the series of plane-- tary sun and fixed gears imparts'its torque to the barrel :58 which rotates within .a bore- 64.

of the: starter shell-.49.. The-.barrel 58- is provided-with acollar spaced from its forward end'whi'ch -bears against theforward end of the shell t9* and prevents rearward movement of the" starter mechanism: The barrel bore is splined-at 86' 'to receive a plurality of externalclutch discstl These discs 8i" are madeof steel facedt-with= a special powdered bronze material. A plurality of inner clutch discs 68 are supported withintthe outer discs 8'! and are sp'lined to thespline nut 89 best shown in Figure 1-2;

A-;.wave type spring 19,, .shown in. detail in Figure 6;: compresses the clutch: discs 61, 68-(Fig.-

which engage with-two (not shown) ure 1) between a clutch plate H and a clutch backing plate 12, thereby transmitting the barrel torque to the spline nut 69. A clutch adjusting nut 13 threaded into an enlarged bore of the barrel 538 permits of clutch adjustment by varying the pressure on the wave type spring 18 upon which it bears.

The spline nut 69, driven by the clutch discs 61,2681; istprevented fr'om=.moving. laterally by means of a'lock-ring 'M' snapped into a groove machined in the rearward end of the said not 69 An internal shoulder 15 is provided, spaced. from the front of the spline nut 69, and the entire bore of the nut 89 threaded with a coarse left hand thread 1 6 A-screw= shaft ll, shown in detail in Figure '7, is threaded within the spline nut 69 by means of a gear 78, shown in Figure 13, having helical teeth machined into a collar l9 on the rearward end of the said shaft 11. The forward end of the screw shaft 'H is. provided with a" collar' fiihinto which is cut a gear 8:! having straight teeth..-

Ther screw shaft I1 is bored from each end. as; shown in Figure 7-. A pierceduwall: 82 integrat with the" shaft 11 isprovided inthe shaft bore mediate-theends of-thesaid shaft 11. Acoupling shaft83- is held within the bore 84 of the wall 82. bears against the :forward 'face" of-the wall 82. A-locki-ringts snapped-intoa groove 81- on eachend of the coupling shaft .83 enables the shaft 83to .jointhe' screw shaft 11 and the starter jaw- 88.

As shown in Figure 1,- the forward end: of the coil. spring 85 bears against a third .lock -.ring 86 on. the. shaft TL- This ring 88* holds :a'metal washer. v89 against a. rubber ring 98;: surrounding the coupling shaft 83, and flush with the back:

of the starter jaw-'88. This rubber. ring 99 preventszioilaor .foreign matter from-entering. the

starter'atrthis point. Protection. is furtherinsured-becausetheshaft 83 doesnot move through;

the jaw- 88 as is the case in presently 'known starters.

The starter jaw-88-is provided with an internalgear 9| which meshes with the gear 8| on the forward 'end of-the screw-shaft TI.- The torque imparted to the screw shaft 11- by the gear train is thereby transmitted to the-starter-jaw;

Afriction: spring 92, shown indetail in.Figure 5-,'is slipped over the-outside diameter. of the starter jaw 88. The springv 92'is formed of twotu-rnsof square wire-wound. so that its inside diameter is smaller than the-outside diameter of. the jaw 88 over which it is sprung; One-end 93 of the spring 92 is bent at right angles to its vertical axis to form aprojecting member. As

shown in: Figure 4; thisbent end- 93 is held within a detent 94 formed inthe baflle plate assembly 95-.- In-this=manner the spring- 92 is prevented from rotating 'with thestarter jaw- 88 which it" encircles.- The cranking rotation of" the starter jaw 88- w-ith-in the spring tends-t0 free the spring- 92 from the jaw 88 by increasing the-inside diameterof the spring 92; The-normal spring friction upon the jaw-88- prevents it'from movingv forward for any reason other than the operation. of the starter. This preventsthejaw teeth 96 from engagingthe running engine I and thereby becoming damaged. The: spring-friction also serves a purpose hereinafter described.

The front end of the starteriscovered; by the baffle plate assembly 95. pilettthe starter to the enginemounting-fiange A coil spring 85 slipped over the shaft-88 This also serves" to The baffle assembly comprisest'aa baffle plate 91 to the inside of which are attached, as by welding, two stamped steel plates 98, 99. The first 98 of these is in the shape of a large washer encircling the starter jaw 88 and retaining upon its inner face the friction spring 92. The second, or jaw support plate 99 has a rearwardly extending rim I39 which forms a bearing surface within which the starter jaw may rotate and which restricts the radial movment of the jaw 88 under engine vibration.

The jaw support plate 99 is also provided with a recess IllI to accommodate the friction spring 92 and a detent 94 to hold the bent end 93 of the said spring. A spring loaded oil seal I82 is pressed into and secured between the starter jaw 88 and the bafiie plate iii! to prevent the entry of engine oil or foreign matter into the starter.

'To facilitate the disassembly of the starter,

camlocks I35 are provided to couple the baffle plate 9! to the starter mounting flange I03. A spacer flange IM is inserted between the baffle plate 91 and the mounting flange I83 to provide flange strength. In removing the starter from the engine mounting flange, the baille plate 9? often becomes frozen to the engine flange. This necessitates much prying and consequent injury to the baffie plate 9? before it can be removed. By holding the baffle plate 97 to the starter mounting flange I83 by means of the camlocks I95, shown in Figure 8, this difficulty is avoided and the problem of removing the starter greatly simplified. A quarter turn of the camlock I85 frees the bafiie plate 9! from the mounting flange I83 and permits of access to the inside of the starter.

The operation of the starter becomes apparent from the foregoing description. The torque provided by the starter motor is transmitted by means of the motor shaft 39 and the driving pinion ll to a series of planetary gears 45, 52, 56, forming part of a gear train. The effect of this mechanism is to greatly increase the torque available at the starter barrel 58. The rotary motion of the barrel 58 is transferred to the spline nut 69 by means of a clutch mechanism adjustably regulated by the tension placed upon a wave spring '59 by the clutch nut I3. The motion of the spline nut 69 would cause the screw shaft I? to rotate but for the operation of the friction spring 92. The friction spring resists this torque by holding the starter jaw 88 to which the screw shaft ll is geared. However, this causes the left hand splines l8 within the spline nut 69 to force the screw shaft ll forward. The starter jaw 88 is yieldably urged forward by the coil spring 85 surrounding the coupling shaft 83 which links the screw shaft H and the jaw 88. The forward travel of the screw shaft El and jaw 88 is stopped by the shoulder 75 in the spline nut 89, whereupon the entire barrel assembly, including the clutch jaw 88 rotates, thereby cranking the engine. When the screw shaft l'l reaches the end of its travel the rotation of the jaw 88 expands the friction spring 92 and frees the jaw 88 for rotation.

When the motor is at rest, the screw shaft H, as well as the starter jaw 88 splined to it must rotate in the direction opposite to the cranking direction in order for these parts to move forward. This opposite direction of rotation, however, causes the friction spring 92 to become more tightly wound around the outside diameter of the jaw 88. Thus the jaw 88 is held from moving, under engine vibration or airplane maneuvers, into a position of contacting the running engine which would cause serious injury to the starter and its jaw 88.

The jaw 88 of the starter is provided with inclined teeth so that the starting of the engine under its own power and its consequent crankshaft speed in excess of the starter speed causes the starter jaw 88 to be thrown clear of driving engagement and possible damage.

The starter shell 49 is attached, as by welding, to the yoke I5 of the motor section. The two are then bored and machined to the desired shape. This promotes concentricity throughout the starter and improves its performance and durability.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States, is:

1. In an engine starter, a source of rotary power, a reduction gear train driven by said power source, a barrel driven by the gear train, a clutch mechanism coupled'to the barrel, a spline nut driven by the clutch, a screw shaft rotatably carried within the said spline nut and driven thereby, a jaw member slidably carried upon the screw shaft and driven by the screw shaft, a baffle plate having a jaw receiving opening therein upon the front of the starter, a coil spring carried upon the jaw member, said spring having an outwardly disposed detent thereon secured to the baffle plate and an internal diameter slightly smaller than the outside diameter of the jaw member, said spring being adapted to permit the jaw to rotate in only one direction.

2. In an engine starter, a source of rotary power, a reduction gear train comprising a stationary internally geared housing and a plurality of planetary gears in mesh with the internal gear, driven by'said power source, a barrel driven by the gear train, a clutch mechanism coupled to the barrel, a spline nut driven by the clutch, a screw shaft rotatably carried within the said spline nut and driven thereby, a jaw member slidably carried upon the screw shaft and driven by the screwshaft, a baffle plate having a jaw receiving opening therein upon the front of the starter, a coil spring carried upon the jaw member, said spring having an outwardly disposed detent thereon secured to the bafiie plate and an internal diameter slightly smaller than the outside diameter of the jaw member, said spring being adapted to permit the jaw to rotate in only one direction.

3. In an engine starter, a source of rotary power, a reduction gear train comprising a unitary stationary, internally geared housing and a plurality of planetary gears in mesh with the internal gear, driven by said power source, a barrel driven by the gear train, a clutch mechanism coupled to the barrel, a spline nut driven by the clutch, a screw shaft rotatably carried within the said spline nut and driven thereby, a jaw member slidably carried upon the screw shaft and driven by the screw shaft, a bafiie plate having a jaw receiving opening therein upon the front of the starter, a coil spring carried upon the jaw member, said spring having an outwardly disposed detent thereon secured to the baffle plate and an internal diameter slightly smaller than the outside diameter of the jaw member, said spring being adapted to permit the jaw to rotate in only one direction.

4. In an engine starter, a source of rotary power, a reduction gear train comprising a stationary, internally geared housing and a plurality ofpl'anetary-gears' in mesh with-the internal gear,- driven by said power source, a 'barrel driven by.

the gear train, a clutch mechanism coupled to the barrel comprising a plurality of clutch plates, a wavespring compressing the plates and a tension nut held within the bore ofthe barrel, a. spline nut driven by the clutch, a screw shaft rotatably' carried within the said spline nut and driven thereby, a jaw member sli'dably carriedupon the screw shaft and driven by the screwshaft', a=baffle platehaving a jaw receiving opening therein uponthefront of the starter, a coil spring carried upon the jaw member, said spring having an outwardlydisposed detent thereon. secured to the.

the gear train, a clutch mechanism coupled to.

the barrel comprising: aplurality of clutch plates, a-wave spring compressingthe plates and a tensionnutzheld within the bore. of the, said barrel. a spline nut driven by the clutch, a screw shaft rotatably carried within the said spline nut and driven thereby, a jaw member slidably carriedupon the screw shaft and driven by the screw;

shaft, a balile plate having a jaw receiving opening therein upon the front of the starter, a coil" spring comprising turns of square wire carried? upon the jaw member, said spring having an outwardly disposed detent thereon secured to the bafile plate and an internal diameter slightly smaller than the outside diameter of the jawv. member, said sprin being adapted to permitthev jaw to rotate in only one direction.

ROMEO M. NARDONE.

REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date I 1,810,204 Dickson June 16, 1931; 1,962,397 Lansing June 12,1934 1,965,059 Nardone July 3,1934: 2,412,829 Nardone Dec. 17, 1946

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