US2663804A - Autoamtic starter for internal-combustion engines - Google Patents

Description

Dec. 22, 1953 WOLF 2,663,804

AUTOMATIC STARTER FOR INTERNAL-COMBUSTION ENGINES Filed May 2, 1950 INVEN TOR.

Patented Dec. 22, 1953 AUTOMATIC STARTER FOR INTERNAL- COMBUSTION ENGINES Walter A. Wolf, Logansport, Ind., assignor to Switches, Inc., Logansport, Ind., a corporation of Indiana Application May 2, 1950, Serial No. 159,526

6 Claims. 1

My invention relates to improvements in starter switches for internal combustion engines.

More particularly, my invention relates to i1nprovements in the type of starter switches wherein an electromagnet energized by an engine driven generator, is relied upon to hold the starter switch in the open circuit position when the engine is running.

In the prior art devices of this general class, it is essential that a minimum supply of energy sufiicient to operate the electromagnet be forthcoming from the generator both at idling and throughout the entire range of operating engine speeds; otherwise, the switch will close to engage the starter mechanism. This frequently results in stripping the teeth from the flywheel of the engine or in other serious damage to the starting mechanism. While in theory the generator may be set to deliver ample energy at all engine speeds to disable the starter, and while this performance is usually obtained in the case of new equipment, such factors as loose generator belts, improper setting of the generator, and worn brushes, may cause the generator voltage output to drop at idling and part throttle engine speeds to a level at which the electromagnet will not hold the starter switch in the open position.

A cordingly, it is the principal object of my invention to provide a starter switch for internal combustion engines in which the switch is held inoperative at idling and part throttle engine speeds, regardless of the energy supplied by the generator to the electromagnetic device of the switch.

Another object of my invention is to provide a starter switch of the character described which is easily to install, dependable in use, and in expensive to manufacture.

.To the end of achieving these objects, my iii- .vention, as installed, comprises (1) a switch for opening and closing the circuit of the starter motor for the engine, (2) energy storing means such as a spring urging the switch into the closed circuit position, (3) movable stop means normally resisting movement of the switch into the closed circuit position, (4) means actuated by the engine throttle control, when the .latter sets the engine to operate at high speeds, for moving the movable stop means to allow movement of the switch into the closed circuit position, and (5) electromagnetic means energized by the engine generator to prevent movement of said switch into the closed circuit position, regardless of the position ofsa-id movable stop means, as

long as the engine is operating at medium and high speeds. In one application of my invention the switch is placed directly in the circuit of the starter motor for the engine. In another application the switch serves as a relay for opening and closing a conventional solenoid starter switch in the starter motor circuit.

In order that my invention may be more fully disclosed, reference is had to the accompanying drawing which illustrates one form of apparatus embodying the foregoing and such other principles, advantages and capabilities as may be pointed out as this description proceeds, or as are inherent in the present invention. For purposes of clarity in exposition, the following description is explicit and the accompanying drawing detailed, but it is distinctly to be understood that said exposition is illustrative only, and that my invention is not restricted to the particular details recited in the specification or shown in the drawing.

In the drawing:

Figure l is a vertical cross sectional View of an automatic starter embodying my invention, an exemplary wiring diagram for use therewith being shown schematically;

Figure 2 is a vertical cross sectional view of the embodiment of Figure 1, as it appears when set in the starting position; and

Figure 3 illustrates a second application of my invention, in which it serves as a control relay rather than as the primary starting switch.

Like reference characters designate like parts in the drawing and in the description of my invention which follows hereafter.

Referring now to the drawing, and more particularly Figures 1 and 2 thereof, my automatic starter is'shown as including a casing ill, a par" tition H and an insulating plate 12 therein, and

two binding posts :2 and It extending on opposite sides from the casing ill. The binding post i2 secures the contact H5 in place and is insulated from the casing it by the insulating washers I4 and 45. The lock washer ll and nuts l8, IBiasten the binding post 42 in place, and also provide means for connecting said post l2 to a starter motor i9 of an internal combustion engine through the wiring 29. Similarly, the binding post 13 is insulated from the casing It by the insulating washers 22 and 21, and positions the contact 2! as shown. Lock washer 23 and nuts 24, 24 fasten the post l3 in place, and provide means for connecting the binding post 2 to a battery 25 or other source of energy through the wiringit.

ascasoc 3 Extending downwardly from the partition ii plate i2 is a sleeve 28, in which an armatur s slidable. The sleeve 28 supports a carrier ing spool so for the winding 3i of an eiejtroniagnet, designated generally by the numoral One end of the electromagnet winding 3i is connected through the binding post 3 and the wiring to the grounded generator 33, which is driven by the internal combustion engine. The insulating grommet 58 insulates the post 33 from the casing ill, while the nuts 52, 5?. both secure the post 3 in place and facilitate connecting it to the generator 33. The other side of the electromagnet winding 3! is connected to the partition it by the wiring 3t, and is therefore grounded to the casing iii. The electromagnet is so arranged that when the winding Si is energized by the generator 33, the armature 29 is urged downwardly into'the position shown in Figure 1. A spring 3? fits within the bore 33 of the armature 2a, to urge said armature upwardly to the position shown in Figure 2. A contact plate 39 is secured to the upper end of the armature 29, by the fastener it and the washer ll, but is insulated from said armature 22! by the insulating washers 6B, 5i.

A bonnet is secured to the upper end of the casing it, and has a hanged opening i l therein. positioned in the upper portion of the casing it is an insulating plate #25 and a backing plate it, which are spaced from the bonnet by the spring fill. A plunger 38 extends through the flanged opening it and the bonnet :3, and through the opening es in the plates 55 and it. A spring surrounds the plunger t8, and bears against the shoulder portion 5i thereof to urge the plunger it downwardly into the position shown in Figure l. The spring so is purposely made stronger than the spring 3?, so that when no external forces are exerted on the plunger 28, said plunger holds the armature 253 in the position of Figure 1, against the opposition of the spring ill.

The casing is is secured to a bracket 52, whereby the device may be ecured to an internal combustion engine. The end of the plunger 18 is in turn connected to the accelerator rod 53 of the engine, through the spring 5% and the clamp 55. By means of the fastener 55 and 5?, the clamp 55 may be and preferably is positioned on the accelerator rod so that it is necessary to move the rod 53 to substantially the full throttle position, before the plunger i8 is moved against the opposition of the spring 5? to the position shown in Figure 2.

The spring urging the shoulder portion 5% of the plunger it, forces the armature 23 to the position of Figure l, by overpowering the spring With the armature 29 thus depressed, the contact plate St is spaced from the contacts i5 and 2 i, so that no energy can flow from the battery '25 to the starting motor !9.

When the accelerator rod 53 is actuated, as for example by fully depressing the accelerator foot pedal, the spring is put under tension, and the plunger pulled from the position of Figure 1 to the position of Figure 2. When this occurs, the spring 3? moves the armature 29 upwardly, until the contact plate 35 bridges the contact i5 2i. This completes the circuit between the battery 25 and the starting motor as, whereupon the starting motor it cranks and starts the engine.

As soon as the engine starts, the normal reaction of the operator is to allow the accelerator foot pedal which controls the accelerator rod 53 to return to the idling or part throttle position. The plunger is thereupon returns to the position of Figure l, and moves the contact plate 3d away from the contacts it and 2!, to open the circuit or" the starter motor it. the same time, the engine drives the generator 33, which energizes the winding iii of the electromagnet 32. The strength of the magnetic field of the electromagnet 32 normally is sufiicient to move the armature 29 downwardly against the resistance of the spring iii. However, the starter switch does not rely upon the electromagnet 32 to break the contact between the contacts is and 22 and the plate 35, since as the engine is started up, the plunger iii; makes positive this action. Thus, even though the output of the generator 33 at idling or part throttle speed may be insui'llcient to cause the electromagnet to overcome the upward force of the spring 3?, the plunger insures that the circuit of the starter motor iii remains open, so that motor it cannot engage the starting mechanism of the internal combustion engine.

As the engine is accelerated, by the movement or the accelerator rod 53, the spring 54 is pulled taut and moves the plunger is away from the contact plate As the engine picks up speed, however, the output of the generator also increases, so that as the engine is turning at for example one-half throttle, the generator is energizing the electromagnet 32 sufficiently to easily overcome the resistance of the spring 3? and maintain the armature 29 in the open circuit position of Figure 1.

It will be seen that my invention provides positive action means for maintaining the circult of the starting motor it open at all engine speeds. At low speed the spring all is the principal force maintaining the circuit or the motor i9 open, while as the speed of the engine increases this function is assumed by the electromagnet 32. Thus at low engine speeds, when the performance of the electromagnet 32 is least dependable, and may even be insumcient to resist the upward force of the spring 3?, other means which operate independently or" the speed of the engine, are used to maintain the circuit of the starter motor it open.

While in the application of my invention illustrated in Figures 1 and 2, the contacts it and 2i and the contact plate 59 are placed directly in the circuit of the starting motor it, in certain applications it may be desirable to use my in vention in the manner of a relay, rather than as the primary starter switch. When this is the case, the arrangement shown in Figure 3 may be used to advantage. More particularly, in this application the binding post 52 is connected through the lead to the solenoid post 63 of a conventional solenoid starter switch t l. One terminal 65 of the starter switch is connected to the starter motor is through the lead 6?, while the other terminal 58 of the switch E4 is connected to the battery 25 or other source of electrical energy through the lead 69. Also connected to the battery 25 through the lead it is the other binding post it of my device. Since the current flowing to the binding post it through the lead is substantially less than the starter motor current, it is practical to interpose the ignition switch it in the lead it.

Using the circuit arrangement of Figure 3, when the plunger (is is extracted from the casing it, to close the contact plate 39 against the yer contacts it and. 2 I ,current flows from the battery 25ththe solenoid post 63, whereuponthe solenoid starter switch 64 closes the circultibetween the startermotor l9 and the battery 25. As the in ternal combustion engine starts up, the operaion of a plunger 48 and the related apparatus within the casing I is the same as thatoutlined-above in connection withFi'gures .1 and 2. The only difierence between the arrangement of Figures 1 and 2 and that of Figure 3 is therefore one of application rather than principle of :operatiomin the first instance myinvention-being used asiaiprimary starter switch,:whereas in the second instance it serves as a relay which :actuates the primary starter switch.

:Having thus fully disclosedzmy novel automatic starter for internal combustion engines, and illustrated its utilitybyreferenceto certain specific applications thereof, I claim as my invention:

1. A starter for the starterxmotor of aninternal combustion engine including a throttle control, a generator driven by sa d engine, and a source of electrical energy for said starter motor, said starter comprising; a casing, an electromagnet mounted in said casing electrically connected to said generator as the latter is driven by said engine, a first switch contact connected to said starter motor, a second switch contact connected to said source of electrical energy, an armature in said electromagnet and including a contact member for bridging said first and second switch contacts, said armature being operated by said electromagnet to open said switch contacts upon energizing said electromagnet, a first spring urging said armature to close said switch contacts, a plunger slidable in said casing and positioned for engagement of said armature, an end of said plunger extending through said casing, a second spring, said second spring being stronger than said first spring and engaging said plunger to move said plunger into engagement with said armature to open said switch contacts, and a coil spring interconnecting the outer end of said plunger and said throttle control, tensioning of said coil spring moving said plunger against the resistance of said second spring to permit movement of said contact member to bridge said switch contacts, the strength and initial tensioning of said coil spring being such that the resistance of said second spring is not overcome until said throttle control is in the substantially fully open position, whereby at idling and low engine speeds said second spring is operative to maintain said switch contacts open independent of the influence of said electromagnet on said armature.

2. A starter for the starter motor of an internal combustion engine including a throttle control, a generator driven by said engine, and a source of electrical energy for said starter motor, said starter comprising: a casing, an electromagnet mounted in said casing and electrically connected to said generator as the latter is driven by said engine, a first switch contact connected to said starter motor, a second switch contact connected to said source of electrical energy, an armature in said electromagnet and including a contact member for bridging said first and second switch contacts, said armature being operated by said electromagnet to open said switch contacts upon energizing said electromagnet, a first spring urging said armature to close said switch contacts, a plunger slidable in said casing and positioned for engagement of said armature, a second spring, said second spring stronger than said first spring -an'd engaging said plunger to move said'armature to open'said switch contacts, and

means interconnecting said plunger and said throttle control'forovercoming the resistance of said'second'spring when said throttle control is substantially fully opened, to permit movement of said armature to close said switch contacts. whereby'at idling and low engine speeds said second spring is operative to maintain said switch contacts open independent of the influence of said electromagnet on said armature.

'3. A starter control for internal combustion engines including a throttle control, a generator driven. by said engine, a starter motor and a source of electrical. energy, said starter control comprising an electrical connection including a switcliibetween said-starter motor and saidsource of electrical energy, said switch comprising a movable contact plate for opening and closing said switch, an electromagnet connected to said generatonian armature in said electro-magnet, said contact plate being connected to one end of sai'd armaturc, sai'd armature being operated by said electromagnet when the latter is energized to'move said contact plate to open said switch, a

first spring engaging said armature to move the same to close the switch, a plunger movable to engage one end of said armature, a second spring stronger than the first spring engaging said plun ger for shifting the same for opening said switch against the pressure of the first spring, a coil spring connecting the outer end of said plunger with said throttle control, the strength and initial tensioning of said coil spring being such that said throttle control must be substantially fully opened to move said plunger out of contact with said armature.

4. An automatic starter for internal combustion engines including a throttle control, a generator driven by the engine, a starter motor and a source of energy; said starter comprising a circuit connecting said starter motor and source or energy, a switch in said circuit having a movable contact plate for opening and closing said switch, means for moving said plate for controlling said switch, energy storing means acting upon said contact plate moving means for closing said switch, movable stop means normally resisting movement of said contact plate moving means to switch closing position, means connected to said throttle control for moving said movable stop means to allow movement of said contact plate to switch closing position when said throttle control is in substantially full open position, and electromagnet means connected to said generator and energized thereby when said generator is driven by the engine, for operating said contact plate moving means against the opposition of said energy storing means to position said contact plate in switch open position.

5. An automatic starter for internal combustion engines including a throttle control, a generator driven by said engine, a starter motor and a source of electrical energy, means for electrically connecting said starter motor and source of electrical energy including a switch having spaced switch contacts and a movable contact plate, an armature connected to said plate contact, a spring engaging said armature for urging same for moving said plate for closing said switch, an electromagnet surrounding said armature and electrically connected to said generator and normally eiiective for moving said armature for opening said switch, a casing surrounding said starter, a plunger in said casing and connected o if to said throttle, and a spring for normally urging said plunger for engaging said armature for opening said switch, said last named spring overcoming the tension of the first mentioned spring.

6. fhe combination with an ignition fired combustion engine including an electric cranking motor, a, power generator driven by said engine, and a mechanical accelerator for said engine, of a switch for controlling an energized circuit for said cranking motor, which switch comprises a pair of contacts, a member movable toward and away from position for operating said contacts, a first spring for urging said member toward said position, an electromagnet included in a circuit which is connected to said power generator for moving said member away from said position, an armature in and operated by'said electromagnet for overcoming said first spring, a second spring for also urging said member away from said position and independently capable of overcoming said first spring, and a third spring operated by said mechanical accelerator for neutralizing said second spring coincident with engine acceleration.

WALTER A. WOLF.

References Cited in the file of this patent UNITED STATES PATENTS Number Number

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