US3496787A

US3496787A - Positive-control electric starter

Info

Publication number: US3496787A
Application number: US683323A
Authority: US
Inventors: Lucien Guillemart
Original assignee: Automobiles Peugeot SA; Renault SAS
Current assignee: Automobiles Peugeot SA; Renault SAS; Regie Nationale des Usines Renault
Priority date: 1966-12-28
Filing date: 1967-11-15
Publication date: 1970-02-24
Anticipated expiration: 1987-02-24
Also published as: GB1210669A; DE1626012B2; FR1512520A; DE1626012A1; DE1626012C3

Description

L. GUILLEMART POSITIVE-CONTROL ELECTRIC STARTER Feb. 24, 1970 7 Sheets-Sheet 1 Filed NOV. 15, 1967 Feb. 24, 1970 L. GUILLEMART 3,

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 7 Sheets-Sheet 2 Feb. 24, 1970 L. GUILLEMART 3,496,787

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 7 Sheets-Sheet 5 Feb. 24, 1970 GUILLEMART 3,496,737

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 '7 Sheets-Sheet 4 Feb. 24, 1970 L. GUILLEMART POSITIVE-CONTROL ELECTRIC STARTER 7 Sheets-Sheet 5 Filed NOV. 15. 1967 a Q/ NA L. GUILLEMART POSITIVE-CONTROL ELECTRIC STARTER Feb. 24, 1970 '7 Sheets-Sheet 6 Filed NOV. 15, 1967 Feb. 24, 1970 GUILLEMART 3,496,

POSITIVE-CONTROL ELECTRIC STARTER Filed Nov. 15, 1967 '7 Sheets-Sheet '7 United States Patent 3,496,787 POSITIVE-CONTROL ELECTRIC STARTER Lucien Guillemart, Billancourt, France, assignor to Regle Natiouale des Usines Renault, Billaucourt, and Automobiles Peugeot, Paris, France Filed Nov. 15, 1967, Ser. No. 683,323 Claims priority, application France, Dec. 18, 1966,

1 89,14 Int. Cl. G05g 5/06; H02k 7/118 US. Cl. 74527 18 Claims ABSTRACT OF THE DISCLOSURE This invention relates to electric starter motors of the positive control type, notably for internal combustion engines.

' It is known to use electric starter motors wherein a drive adapted to be connected to the engine is disengaged therefrom automatically, usually by spring means, when the engine is running, this drive consisting as a rule of a pinion, a free-wheel device and members associated therewith which are adapted to slide in straight or helical splines formed in the starter motor shaft. When it is desired to start the engine, positive control means urge the drive towards the toothed ring of the engine fly-wheel until the drive pinion'is in meshing engagement therewith.

This positive control action was formerly actuated by using a pull knob but nowadays the use of a plunger-core electromagnet or solenoid acting upon a drive fork has become widespread.-

In either case the return spring restores the drive to its initial position when the engine is-running and the drive is disconnected. 6

Now due to the developments of modern engines, notably their lighter weight and the increment in their rotational speed, more and more considerable vibration is produced and attended by very small relative movements of the various component elements; now these small displacements of the movable parts, notably of the drive on the splined armature shaft, are a source of considerable wear and tear, accompanied by a degradation of the lubri- "cant (grease), and, moreover, by a tendency of the pinion to crawl towards the fly-wheel ring. As a result, the drive tends to compress its return spring balacing the stray driving forces caused by said vibration.

In certain types of engines and under certain conditions it may happen that this state of balance is not reached when the drive pinion engages the fly-wheel ring; as a consequence, the pinion is milled off very rapidly, thus requiring a premature reconditioning of the starter motor.

- It is the essential object of the present invention to provide an improvement in or relating to starter drives whereby the above-mentioned inconveniences can be avoided by positively preventing the drive from reaching the engine toothed fly-wheel. This improvement is characterised primarily in that it comprises a device associated with the drive control means, which incorporates mechanical, electro-mechanical or other suitable means for positively retaining the drive in its inoperative position .by locking or self-locking the whole or part of the drive.

ice

According to another feature characterising this invention the afore-mentioned locking action is obtained either by using the electromagnet of the drive control means or with the assistance of a power member other than said drive control means. 7

Other features of this invention will appear more clearly as the following description proceeds with reference to the accompanying drawings illustrating diagrammatically by way of example a few typical forms of embodiment of this invention. In the drawings:

FIGURE 1 illustrates diagrammatically the more of operation of a conventional starter motor drive;

FIGURE 2 illustrates the core of the control electromagnet and the fork head after the energizing circuit of the starter motor has been switched off;

FIGURE 3 illustrates the relative position of the core strap and of the fork head at the beginning of an engine starting operation;

FIGURE 4 shows a first form of embodiment of the locking device according to this invention;

FIGURE 5 illustrates another form of embodiment of this device which provides a friction action;

FIGURE 6 shows a ditferent form of embodiment providing a self-locking action;

FIGURE 7 shows another form of embodiment of the locking means;

FIGURE 8 shows another form of the embodiment using a bell-crank locking means.

FIGURE 9 shows a further form of embodiment providing a self-locking action, and

FIGURE 10 is a wiring diagram of the device illustrated in FIGURE 9.

In the conventional starter motor drive arrangement as illustrated diagrammatically in FIGURE 1 an electromagnet 1 comprises one or a pair of

windings

2, 3 adapted to attract a soft-iron core 4. The wiring diagram of the windings is associated with the wiring diagram of the starter motor; thus, the winding 3 is connected to the circuit of the series-wound motor 5 of the starter motor; a storage battery 6 provides energizing current for the pair of

windings

3, 3 via a starter switch 7 and for the motor directly through the main switch 8 responsive to said core 4. When switch 7 is closed, both

windings

2 and 3 are energized and thus attract the core 11, whereby the latter, by means of the cross-pin 9 carried by its end strap 10, carries along the head of the fork '4 by causing the latter to pivot about its fulcrum pin 12. The fork r11 thus positively controls in turn the movement of the drive (not shown) towards the fly-wheel ring by meansof shoes, clamps, studs or like member 13. Then the starter motor is energized under a reduced voltage until the core 4 closes switch 8 (as shown in FIGURE 1), thus short-circuiting coil 3 and causing the motor starter '5 to operate under maximum power conditions. When the engine begins to fire, switch 7 is re-opened and the pair of

windings

2 and 3 are de-energized. s

The reaction produced by the helical splines of the armature shaft on the starter drive keep the latter in meshing engagement with the fly-wheel ring if the engine does not start; now if some cut-out play were not provided, the fork action would prevent any opening of the main switch 8.

This cut-out play I, which may be obtained in various ways, is illustrated diagrammatically in FIGUREZ in the form of a lost motion of pin 9 in the strap of plunger-core 4 in relation to the two

arms

14 and 15 of the U-shaped head of fork 11. The current is cut out in the main switch 8 when the cross pin 9 is caused to engage the front arm 14 by the return spring 16 (also visible in FIGURE 4), the drive being in its operative position in this case. As the return spring keeps urging the core 4 backward during thelastiraction. of its stroke, t i e-4..meve e fork at 9' against the rear arm 15 of the U-shaped fork head so that this fork begins to rotate as shown in FIGURE 3. It is this lost-motion stroke which is utilized according to this invention forproviding a simple yet eflicient and economical solution to the problem of locking and releasing the starter drive. I

According to a first form of embodiment of this'inven- ,frictional engagementthus produced betweenthethrust pin 9 of said strap 10 and the front face 28' of the fork head facilitates this locking action. The roller 20 also acts as a guide member tothe core strap 10 when it is attracted by the electromagnet '17.

In a third form of embodiment illustrated in FIGURE 6 a frictionless self-locking action is obtained by providing'in the strap 10 of core. 4 an elongated hole 29 having its major axis directedvertically and adapted to receive 10 freely therein the pivot pins 19 and 19' of; a pair of superposed

rollers

20 and 20 respectively. The bottom roller 20 engages with its lower portion the upper face 30 'of fork 11 forming an acuate angle a with the longitudinal axis of this fork, and provided with an upward protien, as shown in FIGURE the strap 1 of o e 4 f 15 jection 31. On the other hand this bottom rOller electromagnet 17 has formed therein elongated holes 18 engages the ,top roller 20"" f hi h the':uppe1 portion having their major dimension directed a g t a g s t contacts an adjustment tapered portion 32 of a set screw the core axis A-B; rotatably mounted'in these elongated 33 engaging a tapped hole formed in the end cover 34 holes 18 is the Pivot Pt!-1 19 of a roller 20 constituting of the starter motor, this screw being locked in the set the .thrust member'controlling the movements of fork 11 20 position by a nut 34. A straight cam face may be suband therefore the starter drive 21; therefore, these holes stituted for the tapered portion of said screw. 18 permit a slight vertical free motion of roller 20. D to th action e d b h return spring 15 When the Winding 2 0f gnet 17 is

dethe rollers

20 and 20 rolling on each other will ensure a energized and the drive resumes its inoperative position firm, i.e. playless locking of the drive fork 11. Any movedue to the action of the return spring 16 of the electrot f h d i e h i 21 d h fl h l magnet, the roller 20 engages a bearing face 23 ach e ring will tend to pivot the lever-forming fork 11 in the th the Starter Cover and Parallel to the aXiS O translation clockwise direction and therefore to rotate the rollers of Cote The contour of the bottom 25 0f the 20 and 20 in opposite directions, whereby the top roller U-shaped fork head is so designed that it causes the roller 20 will t nd to move up the taper 32 and the bottom 20 to be urged against Said bearing face 23 When h roller 20 will tend to move up the inclined plane 30 in fork tends to Pivot about its Pivot P 12 as a conseorder to reinforce the locking or wedging action. When quence of the effort exerted by the starter drive 21 which th rel is caused by the attraction-of plunger core 4 is transmitted through the P y 26 t0 the Shoes 13 O by coil 22 the rollers 20, 20' will roll equally on the said fork 11. In this case, the drive 21 is locked against i li d plane 30 of fork 11 d on h dju tment taper motion. 32

This locking'action is released when the core 4 is at- According to a fourth form, of embodiment illustrated ttacted y the Winding as a conseqllehee 0f the in FIGURE 7 of the drawings the locking action is engagement of roller 20 fromseid bearing face w .produced by means of a separate strap 35 shown in secfact, when the roller 20 leaves the bearing face 23 it can tion, The core 4 is connected 5 this strap by means of a move freely in a Vertical Plane due to the Provision of the pin 36 movable in an elongated hole and adapted to slide elongated holes Thus, the fork 11 can Pivot e y in a tubular portion 37 of the strap. The front end of When the roller 20 has reached the front face 27 0f the this tubular portion comprises notches 38 and the afore- U- P fork headsaid pin 36 isv adapted to engage the bottom of these Conversely, when the energizing current has been cut notches When the core 4 is attracted by the coil 22. 7 out in the electromagnet coil and the magnetic field .Radial holes 39 formed in the tubular portion 37 are has thus been removed, the return movement is controlled adapted to receive balls 40 which in the inoperative. posiby the return spring 16 after a cut-off stroke. Thus, roller tion of said core and

fork

4, 11 engage a fixed cam face 20 engages the rear face 28 of the U-shaped head of fork 41 formed in an inner annular groove or cavity 42. The 11, d ubs u ntl moves the drive 21 to its inoperative core 4 is formed at its front end with a movable cam face position. At the end of its stroke," the roller 20 is re- 43 enabling the balls 40 to be disengaged from said fixed inserted between the bearing plane 23 of the starter cover cam face 41 when the core is attracted. The strap 35 com- 24 and the inner face 25 of the U-shaped fork head. p ses at one end a cross pin 9 adapted to push the strap The arrangement illustrated in FIGURE 4 is of the on the fork 11 and at the core end another cross pin locking type without any self-locking action, for in the 44 whereby the core 4 can push the strap 35. inoperative position the bottom 25 of the fork head is sub- When the drive 21 exerts an. eifort'on the fork 11 by stantially parallel to the plane of said bearing face 23 means of p l y 16 d Shoes 13, and assuming that h and thus the plays likely to exist or develop in the various fork 11 is in its inoperative position, the core 4, by holdmechanical connections are not taken up. ing theballs 40 in their outermost position, will lock the In a modified form of embodiment of this invention strap 35 and ttherefore the fork, since these balls engage which is illustrated diagramatically in FIGURE 5, the the external groove or cavity 42 and are urged against from hearing face 28' of the U-shaped head of fork 11 the cam face 41 thereof. is inclined in the inoperative position, with respect to the According to a fifth form of embodiment shown in axis of translation of core 4, so that if an effort F is FIGURE 8, a bell-crank lever 45 fulcrumed at 46 interexerted on the pulley 26 of drive 21, the force exerted by connects the electromagnet core 4 and the fork 11.-To this the return spring 16 against the core 4 and transmitted end, this fork comprises two

slideways

47, 48 between through the pin '9 of strap 10 creates a'thrust applied to which the push member 49 carried by the strap-shaped said fork 11 which tends to take up the plays of pulley end of the outer arm of lever 45 is adapted to move. The 26 on drive 21, of shoes 13 on said pulley 26, and of fork other arm of lever 45 has formed therein another pair of =11 on its pivot pin 12. Under these conditions the fork slideways 50 and 51 receiving therebeween the push mem- 11 is locked by the engagement of strap 10 of core 4 her or pin 9 of the strap-shaped portion 10 of core 4. against a roller20 rigid with the cover 24 of the starter By properly calculating-the angle 3 (of approximately case, the inclination of the rear face 28 of said fork 90) formed by the slideway 47 of fork 11 .andthe having an angular value so calculated that the reaction straight line connecting the axis of the thrust pin 49 of produced on the pivot pin 9 of strap 10 is sufficient to said bell-crank lever 45 and its fulcrum 46, ,it is possicause this strap 10 to be locked against said roller. The ble in the inoperative position of the fork to obtain a knee-action locking this fork as a consequence of the efforts exerted by the drive 21 on the shoes 13 of .said fork. I

On the other hand, when'the core 4 is attracted by the coil 22 the thrust pin 49 of bell-crank lever 45 causes the fork 11 to pivot about .its fulcrum pin 12. Due to the specific kinematic arrangement resulting from the disposition of

pins

9, 46 and 49, and also to the, properly selected value of the angle of inclination of slideway 48, the pull produced by com 4 during tthe initial portion of its stroke can be multiplied or increased, this pull being on the other hand reduced during the last portion of this stroke, which is particularly advantageous considering the law governing the coercitive force of electromagnets.

A last exemplary form of embodiment of this invention is illustrated in FIGURE 9. In this modified structure the locking action is produced by using an auxiliary electromagnet having its coil 52 secured to an intermediate bearing 53 of the armature shaft 54 and adapted to hold tthe drive 21 in its inoperative position by exerting a magnetic pull thereon.

As shown in the wiring diagram of FIGURE 10, the winding 52 of this auxiliary electromagnet is not energized when the combination ignition and starting switch 55 is open (position or in the ignition and starting position shown in dash lines in the figure (position D), in which position the

coils

2 and 3 of the control electromagnet are energized to attract the core 4 controlling in turn the main starter switch 5. The coil 52 is energized only when the aforesaid combination switch 55 is in its ignition position (position A).

To avoid a too fierce braking of the starter motor by the auxiliary electromagnet when the switch 55 is moved from its start position to its ignition position, and when the starter rotates at a relatively high speed, a rotary contact 56 for example of the centrifugal or friction type is inserted if desired in the circuit of coil 52.

Of course the present invention should not be construed as being limited by the specific forms of embodiment described hereinabove and illustrated in the attached drawings, since other modifications and variations may be brought thereto without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. A positive-control electric starter for an internal combustion engine, comprising: a shiftable drive device associated with a rotating shaft of the armature of an electric starter motor; pivotable shift lever means one end of which engages said drive device and the other end of which is fork-shaped; electromagnet means for controlling said drive device, said electromagnet means being energized through a starter switch; a core member forming a part of said electromagnet means and associated with the fork-shaped end of said shift lever means; resilient means for urging said core into its inoperative position; and locking means associated with said core and with the fork-shaped end of said shift lever means for positively restraining the shift lever means against rotation and thereby positively locking said drive device in its inoperative position when said core is in its inoperative position.

2. A positive-control electric starter according to claim 1, wherein the locking means is an electromagnet and is constituted by said electromagnet controlling said drive device, the core of said electromagnet being adapted to lock positively, by mechanical means, said drive device when said electromagnet is not energized.

3. A positive-control electric starter according to claim 1, wherein said locking means is an auxiliary electromagnet having a coil secured to an intermediate bearing of said motor armature shaft and adapted, when energized, to exert a magnetic pull on said shiftable drive device in order to hold it in its inoperative position.

4, A positive-control electric starter according to claim 2, wherein one end of said core member is strap-shaped and is provided with an elongated slot having its major axis disposed at right angles to the axis of said core member, and further comprising a roller carried on said strap-shaped end and having a pivot pin adapted to revolve in said elongated slot, the roller contacting, in the inoperative position of said starter, a U-shaped head of the fork-shaped end of said shift lever and further contacting a fixed flat face extending parallel to the axis of said core member.

5. A positive-control electric starter according to claim 2, wherein the end of said core member is strap-shaped, a thrust transmitting cross-pin is carried by said strap, the fork-shaped end of said shift lever is U-shaped and has an inner front face inclined in its inoperative position with respect to the axis of said core member, said front face constituting a bearing surface of said cross-pin when said shift lever is in inoperative position.

6-. A positive-control electric starter according to claim 5, further comprising a roller having a fixed pivot pin, and wherein the upper face of said strap-shaped end of the core member is adapted to bear against said roller for guiding said strap face, during its translation and for locking said strap by the reaction of the fork-shaped end of said shift lever against said cross-pin.

7. A positive-control electric starter according to claim 2, wherein one end of said core member is strap-shaped, is provided with an elongated slot having its major axis directed vertically and adapted to receive freely therein the pivot pins of a pair of vertical tangentially superimposed rollers in rolling engagement with each other.

8. A positive-control electric starter according to claim 7, wherein the fork-shaped end of said shift lever has a face which forms an angle with the longitudinal center line of the shift lever and is engaged by the lower of said rollers in the inoperative position of said shift lever.

9. A positive-control electric starter according to claim 7, wherein an adjustment taper having an end screwed in the end cover of said starter motor is engaged by the upper of said rollers in the inoperative position of said shift lever.

10. A positive-control electric starter according to claim 7, wherein a straight cam face is rigid with the end cover of said starter motor and is engaged by the upper of said rollers in the inoperative position of said shift lever.

11. A positive-control electric starter according to claim 2, wherein said core member is adapted to slide in a tubular portion of a separate sliding strap inserted between said core member and the fork-shaped end of said shift lever, said strap being provided with a first crosspin receiving the thrust of said core member, and a second cross-pin engaged in the fork-shaped end of said shift lever to transmit said thrust.

12. A positive-control electric starter according to claim 11, wherein said separate strap is provided in said tubular portion with recesses adapted to receive balls and with notches on the side nearest the shift lever.

13. A positive-control electric starter according to claim 12, wherein fixed cavities having a cam face are adapted to partly house said balls, said cam face constituting an abutment therefor.

14. A positive-control electric starter according to claim 12, wherein said core member is formed with a cam face and its end comprises a cross-pin, said balls being able to be released by said cam when said core member is attracted, and said cross-pin being adapted to engage the bottom of said notches of the separate strap.

15. A positive-control electric starter according to claim 2, wherein said core member has a strap-shaped head with a thrust pin moved between two slideways of one arm of a bell-crank lever fulcrumed on a fixed pivot pin and interposed between said strap, and saidshift lever.

' 16. A positive-control electric starter according to claim 15, wherein said bell-crank lever has on its other arm a strap-shaped portion carrying a thrust pin and said shift lever has two slideways formed on its end, said pin being movable in said slideways causing said bellcrank lever to pivot about said fixed pin;

17. A -positive-control electric starter according to claim 3, wherein said auxiliary electromagnet is fed through the combination of a starter and ignition switch of the engine only in the ignition position thereof.

18. A positive-control electric starter according to claim 17, wherein a centrifugal friction or like rotational switch is inserted in the energizing circuit of said auxiliary electromagnet in .order to prevent same from becoming v 8 energized in case the starter motor speed were abnormally high. 1 a v.

References Cited 1v UNITED STATES PATENTS 2,909,940 Dawkins 74 5 27 10/ 1959' 3,156,125 11/1964 Straub a 74-126 3,177,728 4/1965 Fariso n 310-83 3,223,863 12/1965 Preece er a1. 310 75 3,359,440' 12/1967 West 310-83 FRED c. MATTERN', ]R., Primary Examiner I WESLEY s. RATLIFF, JR., Assistant Examiner US. Cl; X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,496,787 Dated February 24. 1970 Inventor(s) Lucien GUILLEMART It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the Title, change the priority date of "Dec. 18, 1966" to Dec. 28, 1966 SIGNED AND SFAI. E SE? 15197'0 Attest:

mm! 1:. sum, M. Fletcher, I1- com s f fatgntg Attesting Officer