US2151954A - Engine starter - Google Patents

Description

March 28, 1939. E. M. CLAYTOR 2,151,954

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ENGINE STARTER Filed March '7, 1938 2 Sheets-Sheet 2 PEDAL usAaLE To OPERA-re enema THROTTLE 0R OTHER vEmcLE coNTRoL.

70 IGN/TIO INVENTo'R I EowARo N. C LAYToR 2g .-5 BY Patented Mar. 28, 1939 v UNITED STATES PATENT OFFICE ENGINE STARTER Application March 7, 1938, Serial No. 194,282

14 Claims.

This invention relates to engine starting appa ratus and more particularly to the engine starting apparatus in which a pinion driven by the starting motor is shifted by pedal operation into engagement with the flywheel gear of the engine to be started, the pedal operation effecting also the closing of the starting motor switch. In order to prevent driving the starting motor by the engine at an excessive rate of speed and before the pinion is disconnected from the engine after the starting operation, pedal shift engine starting apparatuses include an overrunning clutch between the pinion and the armature shaft of the starting motor. While the manufacturer of engine starting apparatus aims to provide an overrunning clutch which will always overrun under all conditions, it occasionally happens that the overrunning clutch does not function, and the result is that the motor armature shaft is overspeeded before the driver can remove his foot from the operating pedal. If the clutch fails to function for an appreciable length of time, the overspeeding of the motor armature will cause its windings to be dislodgeddue to centrifugal force.

It is an object of the present invention to provide for the control of the engine starting motor in such a way that the pinion will be withdrawn automatically from the engine flywheel gear regardless of whether the driver continues to apply pressure to the foot pedal which controls the starter. To accomplish this object I provide, in the mechanical connection between the operating foot pedal and the lever on the starting motor which shifts the pinion and closes the switch, an electromagnetically operated latch of novel construction differing from similar devices found in the prior art, in that the operation of the latch is independent of the force applied by the car driver to the starter pedal. In the magnetic latches of the prior art the latch members are so constructed and arranged that the forces applied between them, when the driver keeps his foot on the starter pedal, are such as to hinder the unlatching, due to friction set up between the engaging surfaces of the latch members. In the disclosed embodiment of my invention, I so relate these latch parts that the force applied by the driver upon the foot pedal is transmitted in such a way as to tend to unlatch the latch members rather than to set up a frictional force which tends to keep them latched up, regardless of the deenergization of the latch operating magnet.

Further objects and advantages of the present invention will be apparent fromthe following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is 'a fragmentary side elevation partly in longitudinal section of 'an engine starting motor control device embodying the present invention.

Fig. 2 is Va sectional view in the line 2--2 of Fig. 1.

Fig. 3 is a fragmentary view partly in section, the section being taken on the lines 3-3 of Fig. 1.

Fig. 4 is a wiring diagram of a control circuit embodying the mechanism shown in Figs. 1, 2 and 3; and

Fig. 5 is a wiring diagram showing a modified form of the invention.

Referring to the drawings, ydesignates the field frame of an electric motor having an arma- 2 ture 2|, mounted on a shaft 22 journalled in a bearing at the left hand of the field frame 2U not shown. Shaft 22 is jcurnalled in a bearing 23 carried by a gear housing 24 attached to frame 2n. The shaft 22 has a splined portion 25 drivingly connected with a sleeve 2S integral with a driving clutch member or cam 21 of an overrunning clutch comprising also rollers 28 and an outer shell or driven member 29 attached to a pinion 30 carrying a plain bearing 3| which is slidable along a plain cylindrical portion 32 of the shaft 22. A stop ring 33 limits movement of the pinion 3U toward the right into mesh with the flywheel gear 34 (of the engine to be started) A sleeve 35 mounted on the armature shaft 22 limits movement of the pinion shifting sleeve 26 toward the left. A shifting collar, made of iianged members 3B and 31 welded together, slides along the outer cylindrical surface of the sleeve 26 and is retained by a wire split ring 38 received by a groove in the end of sleeve 26. A spring 39 is located between the shifting collar 36, 31 and a shoulder on the sleeve 26, and serves to transmit motion from the shifting collar to the sleeve 26.

The shifting collar 36, 31 receives studs 40 carried by the arms 4I of a bifurcated lever comprising two sections 42 secured to a hub 43 pivoted on a screw 44 which is screwed or press-fitted into a lug 45 integral with the gear housing 24. A anged washer '46 surrounding the screw 45 serves to retain a coiled spring 41 which is retained in an initial state of torsion, one end 48 being received by a lug A49 on the frame 24 and the other end 50 being biased in a clockwise direction against a stud 5| attached to lever parts 42. The lever parts 42 provide an arcuate projection 52 adapted to engage switch plunger 53, which closes switch contacts contained within a switch case 54, mounted upon the motor frame 20, as will be explained in detail in connection with the description of Fig. 4.

The screw 44 provides a bearing for a hub 60 of an operating lever 6| retained on the screw 44 by a Washer B2 and a nut 63 threaded on the end of the screw 44. The operating lever 60 is connected with the gear shifting lever 42 by an electromagnetically controlled latch comprising a latch pin 65 screwed into the lever 50 and retained by lock washer 66 and lock nut 61, and a latch lever 10 having, integral therewith, spaced ears 1| by which the lever is pivotally mounted on a screw 12 threaded into the lever 42 and retained therein by a lock washer 13 and a lock nut 14. 'I'he latch lever 10 is integral also with an armature 15 which cooperates with an electromagnet 16, which comprises a magnetizable cupshaped shell 11 concentric with respect to a magnetizable core 18 surrounded by an electromagnet winding 19. This structure is` attached to a. bracket 80 riveted to the lever members 42, 42.

As stated before, the lever 42 is biased into the normal position shown in Fig. 1 by the spring 41. The lever 6| is biased into the position shown in Fig. 1 by a coil spring 68, surrounding the hub 60 and having one of its ends fixed to the housing 24, and the other of its ends pressing ina clockwise direction against lever El.

The latch lever 10 has a notch 0| which is defined by a long shoulder |12 against which the latch pin 65 normally bears. The other side of the notch 8| is defined by a surface 83 which is not parallel to the surface 82, but makes a substantial acute angle, defined by the lines a--b` and b-c Line b-c is a. radial line extending from the axis of rotation of lever 6|, namely the center of screw 44 and passing through the center of the stop 65. This angle is between 18 and 22; 20o gives satisfactory results.

The latch lever 10 is urged clockwise, so that the latch pin 65 will bottom in the notch 8|, by a spring 90 coiled around the screw 12 and having an end 9| biased counterclockwise against a shoulder 92 provided by lever 42, as shown in Fig. 1, and having an end 93 biased clockwise against that part of the lever 10, which merges into the armature 15, as indicated at 15a in Fig. l, The spring 90 tends to keep the latch members 10 and 65 normally in cooperative relation.

If the operator causes the lever 6| to be moved counterclockwise, the pin 65 will bear against the latch 10 and will attempt to move the lever 42 in a counterclockwise direction, but such movement cannot take place unless the electromagnet 19 is energized. The reason for this is that, the spring 41 which resists movement of the lever 42 being relatively stiff, the reaction of the surface 83 of lever 10 against the pin 65 becomes so great before the resistance of spring 41 is overcome that the force applied between the surface 83 and the latch pin 65 will become great enough to overcome the force of the spring 90 and the latch lever 10 will separate itself from the latch pin 65, and no motion will be transmitted between the lever 6| and the lever 42. It should be noted that the action line of force between the pin 65 and the lever 80 will be at right angles to the line a-b and will pass through the center of the pin B5. 'This force line will, therefore, react in a direction tending always to move the latch lever 10 in a counterclockwise direction against resistance offered by the spring 90. The spring 90 is only a light spring tending to keep the latch members in engagement, but it alone is ineffective to retain the members in engagement unless the spring 90 is aided by the energized electromagnet 19, which urges the armature 15 in a clockwise direction. As will be explained in connection with Fig. 4, the electromagnet 16 is connected in the starter circuit in such a way that, during the starting operation, it will be energized, but when the engine becomes self-operative it will be deenergized. One of the features of the invention is the spring 90 which tends to keep the latch parts in engagement, and which tends also to keep the latch armature 15 relatively close to the magnet 16 so that the air gap is relatively small. Therefore, a much smaller electromagnet can be used to retain the armature in the latch making position, as compared with the conventional type of magnetic latch where the gap between the magnet and latch armature is relatively great.

Referring now to Fig. 4, which shows how the latch magnet is connected with the starting and generating circuit, the operating pedal is indicated by numeral |00 and is connected by a rod |0| with the lever 6|. The switch plunger 53 which is retained in contact open position by a spring 53a carries a bridging contact |02, engageable with stationary contacts |03 and |04. Contact |04 is connected with the circuits of the electric motor which operates the armature shaft 22. The contact |03 is connected by a wire |05 with a battery |01 grounded at |08. The battery is charged by a generator |09 grounded at ||0 and connected with the battery by reverse current relay Relay comprises an electromagnetic core ||2 surrounded by a voltage coil I3 grounded at |4 and by a current or series` coil ||5 connected with a generator by wire IIE and with the hinge of the armature ||1. The armature ||1 carries a contact ||8 which is engageable with the contact ||9 connected by wire |20 and wire |06 with the battery |01. The armature ||1 insulatingly supports a contact 2| engageable with a stationary contact |22. The movable contact |2| is grounded at |23. A spring |24 normally maintains the armature in the position shown in Fig. 4. The contact |22 is connected by Wire |25 with one end of the latch magnet coil 19, the other end being connected by wire |26 with a stationary contact |21 associated with the ignition switch |28. Switch |28 includes contacts |29 and |30, which are bridged together with contact |21 by three-blade bridging contact 13|. Contact |30 is connected by wire |32 with wire |20. Contact |29 is connected with the engine ignition apparatuS.

To start the engine, the operator closes the ignition switch |28, thereby connecting the latch magnet coil 19 with the battery |01 through the following circuit: battery |01, Wire |06, wire |20, wire |32, contact |30, contact |3I, contact |21, wire |26, coll 19, wire |25, contact |22, contact |2|, ground |23 and ground |08. The latch magnet 19 is now energized and the latch members S5 and 10 will be retained in engagement during the engine starting operation. The car driver then presses the starter pedal |00, thereby causing the lever 6| to move counterclockwise, thereby transmitting pressure between the latch pin B5 and the latch lever surface 83, thereby causing the gear shift lever 42 to rotate counterclockwise against the resistance of spring 41. The tendency of the forces exerted between the latch pin 65 and the latch lever surfaces 83 is such as to cause separation of the latch members, but this tendency is resisted by the energized electromagnet 19. Therefore, when this magnet is energized, motion will be transmitted Afrom the pedal |05 to the shifting lever 42 to cause the pinion 33 to be moved into engagement with the engine flywheel gear 34 and the contacts of the starter switch to be closed by the engagement of surface 52 of lever 42 with switch operating plunger 53. In case of abutment of the ends of the teeth of pinion 53 with the ends of the teeth llywheel gear 34 before meshing, motion of the lever 42 is not arrested, because motion is transmitted from the lever 42 to the pinion 30 through the shifting spring 39 which becomes compressed beyond its initial stage of compression and permits closing of the starter switch by the lever 42, whereupon the motor |35 will rotate the pinion 30, thereby bringing it to meshing registration with the gear 34, whereupon the abnormally compressed spring 39 will be released quickly to snap or'jump the pinion 3S into mesh with the flywheel gear 34, whereupon the engine will be started in the usual manner by rotating its crank shaft.

When the engine becomes self-operative, and has attained a predetermined speed, such that the voltage of the generator |09 attains a certain value, the relay will be energized by its voltage coil I l3suiliciently to cause the armature il? to be attracted toward the core H2, thereby closing the contacts IIS and ||9 to complete the battery charging circuit, and thereby opening the 1 contacts l2| and |22 to interrupt the circuit of i'lux lines die away between the armature 'l5 and the core i3 and shell Tl of the latch magnet 16, the force of application between the latch lever surface 83 and the latch pin 65 becomes effective to cause counterclockwise rotation of the latch lever le, thereby interrupting the mechanical connection between the pinion shifting 42 and the pedal operated lever 6l, thereby permitting the spring 5l! to withdraw the pinion 30 from engagement or the flywheel gear 34, regardless of whether the driver consciously or unconsciously fails to remove his foot from the pedal the instant the engine starts.

The present invention provides for the automatic disconnection of the pinion shifting lever from the mechanism directly operated upon by the drivers foot. Consequently the starter pinion is not maintained in mesh with the engine flywheel gear a moment longer than necessary for the starting operation. The instant the engine becomes self-operative and cornes up to speed, the starter pinion is demeshed from the engine gear automaticaly since the clutch magnet is automatically deenergized and permits the spring 4l' to perform its function regardless of whether the driver has released foot pressure on the pedal |00.

During that brief interval of time between the actual beginning of self-operation of the engine and the time when the cut-out relay closes, the engine will be spurting ahead of the starting motor, so that the overrunning clutch will begin to function to prevent the driving of the motor by the engine, but that brief interval is materially shortened due to the fact that demeshing of gears 1 takes place automatically immediately following the closing of the cut-out relay. Therefore, should the overrunning clutch fail to overrun for any reason, it will not be a serious matter, because the latch magnet will become deenergized before the engine speed can attain a value which would be dangerous to the starting motor, should the engine continue to drive it.

In the modified form shown in Fig. 5, the latch magnet 19 is not grounded through an extra set of contacts on the cut-out relay. Instead of the modiiied cut-out relay i Il shown in Fig. 4, I use the conventional cut-out relay represented by the rectangle lila. In this circuit the latch magnet 19 is connected with the generator third brush I09a and gets its ground circuit either through C the armature |091) or through the eld winding 109e. If the brush contact is satisfactory, the circuit of lowest resistance will be directly through the armature; but it may be through the eld circuit |09 if that is the path of least resistance. Obviously, the circuit through field |09 will give a voltage drop in the line thus requiring more ampere turns in the winding 'I9 in order to give sufficient energization. However, the arrangement shown in Fig. is simpler, since the extra set of contacts on the cut-out relay is avoided. Obviously the deenergization of the magnet 'I9 results from opposing the battery C. E. M. F. with generator voltage. While the engine is running the starter cannot be operated. The pedal |00, therefore, can be used to operate other controls of the engine, such as the throttle valve.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A starter for internal combustion engines comprising an electric motor, a current source, a mechanism for connecting the motor with the engine 'to be started and including an overrunning clutch driven by the motor and a pinion driven by the clutch and movable into mesh with the flywheel gear of the engine to be started, pinion shifting member for meshing the pinion, a spring for demeshing the pinion, a starter switch actuated by said member, a pedal operated member, disconneetible means connecting said pedal member and pinion shifting member and comprising normally connected latch parts carried respectively by said members, said latch parts being so related that pressure exerted between them tends to unlatch them, an electromagnet effective to hold the latch parts in engagement during the engine starting operation, and means responsive to self-operation of the engine for rendering the electromagnet inoperative whereby the means connecting the members becomes disconnected due to pressure exerted between the latch members and the spring is released to demesh the pinion regardless of failure tc release the pedal operated member.

2. An engine starter according to claim 1 in which means responsive to the voltage of a generator driven by the engine renders the electromagnet inoperative to hold the latch members in connected relation..

3. An engine starter according to claim 1 in which the armature of the electromagnet is normally at the minimum distance from the pole faces of the electromagnet.

4. An engine starter according to claim l in which one of the latch parts is a pivoted lever connected with the armature of the electromag- 6. An engine starter according to claim 1 in which the pedal operated member and the pinion shifting members are coaxially pivoted levers, in which the latch parts comprise a pin carried by the pedal lever and a pivoted latch plate carried by the pinion shifting lever, and in which the electromagnet core is carried by the pinion shifting lever and the electromagnet armature is integral with the latch plate.

7. An engine starter according to claim 1 in which the pedal operated member and the pinion shifting members are coaxially pivoted levers, in which the latch parts comprise a pin carried by the pedal lever and a. pivoted latch plate carried by the pinion shifting lever, the latch pin bearing, during pinion shifting into mesh with the engine flywheel gear, against a surface of the latch plate which is inclined at an angle of between 18 and 22 with respect to a line intersecting the center of the latch pin and the axes of the coaxially pivoted levers.

8. A starter for internal combustion engines comprising a starting motor, a movable control member for causing the motor to operate, a spring for returning the motor control member to non-operating position, a pedal operated member for actuating the movable member, disconnectible means connecting said members and comprising normally connected latch parts carried respectively by said members, said latch parts being so related that pressure exerted between them, due to the resistance of said spring, tends to unlatch them, an electromagnet effective to hold the latch parts in engagement against the resistance of said spring during the engine starting operation, means responsive to self operation of the engine for rendering the electromagnet inoperative whereby the latch parts become disconnected due to the resistance of said spring which, on being released, returns the motor control member to non-operating position regardless of the status of the pedal operated member, and whereby the pedal operated member is inoperative to control the starting motor while the engine is running.

9. An engine starter according to claim 8 in which means responsive to the voltage oi. a generator driven by the engine renders the electromagnet inoperative to hold the latch members in connected relation.

10. An engine starter according to claim 8 in which the armature of the electromagnet is normally at the minimum distance from the pole faces of the electromagnet.

11. An engine starter according to claim 8 in which one of the latch parts is a pivoted lever connected with the armature of the electromagnet, and in which a light spring is used to maintain the latch parts normally connected and the armature normally close to the magnet pole faces.

12. An engine starter according to claim 8 in which the pedal operated member and the motor control members are coaxially pivoted levers, in which the latch parts comprise a pin carried by one of the levers and a pivoted latch plate carried by the other lever, and in which the electromagnet includes an armature attached to the pivoted latch plate.

13. An engine rstarter according to claim 8 in which the pedal operated member and the motor control members are coaxially pivoted levers, in which the latch parts comprise a pin carried by the pedal lever and a pivoted latch plate carried by the motor control lever, and in which the electromagnet core is carried by the motor control lever and the electromagnet armature is integral with the latch plate.

14. An engine starter according to claim 8 in which the pedal operated member and the motor control members are coaxially pivoted levers, in which the latch parts comprise a pin carried by the pedal lever and a pivoted latch plate carried by the motor control lever, the latch pin bearing, during starting motor operation, against a surface oi the latch plate which is inclined at an angle of between 18 and 22 with respect to a line intersecting the center of the latch pin and the axes of the coaxially pivoted levers.

EDWARD M. CLAYTOR.

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