US2356064A - Engine control device - Google Patents

Description

Aug. 15, 1944- c. H. JORGENSEN ETAL ,ENGINE CONTROL DEVICE Original Filed Sept. 25, 1957 3 Sheets-Sheet 3 :llllk 0 a m m my m in 3 HM E m mm er w a 4 [L 6 8 z a 2 2 0 72 6 3 3 w 2 W 3 0 F c /\7 n m 7 a 3 Z R 0 Z.

g g j, 3 Z 0 w j w W M In M JWATTORNEYS Patented Aug. 15, 1944 ENGINE common nnvros Clarence H. Iorgensen and Lawrence C. Dermond,

Anderson, Ind., assignors to GeneralMotors Corporation, Detroit, Mich., a corporation of Delaware Original application September 23, 1937, Serial No. 165,326. Divided and this application May 16, 1944, Serial No. 535,819

16 Claims.

This invention relates to mechanism for controlling the operation of starting devices for internal combustion engines, particularlythose of automotive vehicles. I

Semi automatic devices for controlling the operation of the starting motor have been provided which have been so constructed that the starting motor is caused to operate in response to actuation of one of the control members which must be manipulated by the operator of the vehicle to, control the operation of the engine as, for instance, the accelerator pedal, but which are also controlled by engine suction in such a way as to render the starting motor inoperative when the engine operates under its own power. Devices of this kind have been provided with a control switch operable in response to variations in engine suction which is so constructed as to be opened by suction as soon as the engine becomes self operative in order to break the circuit of the starting motor and thus render said motor inoperative.

In the past, difllculty has been encountered in designing a control switch of this character which would be held open at all times that the engine is operating under its own power, but

which would not be opened by the suction thereon which is efiective during the cranking" of the engine by the starting motor in order to start the engine.-

It is the principal object of the present invention to provide a starter control apparatus of the character referred to which employs a control switch provided with means to prevent any possible opening of the switch during operation of the engine by the starting motor but which will enable the switch tobe automatically maintained open during operation of the engine under its own power.

This application is a division of applicants copendlng application S. N. 165,326 filed Sept. 23; 1937.

Further objects and 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: I

Fig. 1 is a side elevation of a dual carburetor in which the automatic mechanism for controlling the action of the choke valve and the engine starter is embodied.

Fig. 2 is a'sectlon along the line 2-2 of Fig. 1 with certain parts shown in elevation.

Fig. 8 is a horizontal section on the line 3-4 of Fig. 2 with certain parts shown in elevation,

Fig. 4 is a detailed sectional view on the line 4-4 of Fig. 8-

Fig. 5 is a diagrammatic section partly in elevation o! the whole unit.

Fig. 6 is a detailed sectional view of the switch-. operating mechanism showing the parts in the position occupied while the engine is being started.

Fig. 7 is a diagrammatic view of the circuit of the starter controlled system.

Referring primarily to Figs. 1 and 5, the reference numeral l0 indicates the carburetor in its entirety, such carburetor being provided with two advantages of the present valves 16 and II respectively, carried by a common shaft 20, while the number 22 indicates a fuel chamber of conventional type which partly surrounds the intake passages and supplies fuel thereto in any desirable way. The carburetor is of the down-draft type and is attached when in use to the intake manifold indicated at 24, while adjacent the manifold and case integral therewith is a chamber 26 through which exhaust gas passes. This may be the exhaust manifold itself,

or may be a chamber connected for use combining what is known in the art as a hot spot."

This chamber supplies the heat that is utilized to heat the thermostat which regulates the choke valve in a manner hereinafter more fully described.

An operating connection for the throttle shaft of a conventional type is provided which is not shown' and a connection ll extends from the throttle shaft to an accelerator pump, this mechanism being no part of the present invention.

An unbalanced valve 32 is positioned in the air inlet I4 and the valve 32 is secured of! center on a shaft 36 which is Journaled for rotation in the walls of the air inlet 34 and is operable by the pressure of the incoming air. This valve obviousiy regulates the admission of air to the carburetor and the air flowing past such valve is mixed with fuel to form the mixture which is supplied by the passages l2 and M to the engine.

The shaft it to which the unbalanced valve is secured is adapted to be operated by mechanism a recess 44 formed in one end of shaft and is keyed thereto. The other end of the flexible cable projects into a similar recess 46 formed in the upper end of a shaft 40 which is journaled in a sleeve 50 received in the housing 00 as indicated in Fig. 1. The shaft 40 is suitably journaled for rotation and also journaled for rotation on the sleeve in a manner which does not constitute a part of this invention and. is not shown herein, is a segmental gear I2, by means of which the suction operated mechanism is adapted to rotate the shaft 48, such suction operating mechanism operating through the medium of the thermostat as will be now described.

Depending from the segmental gear is a pin 44 which is suitably secured to the segmental gear and engages in a slot 50 formed in a bifurcated member 58, best shown in Fig. 5, which is secured by rivets, or in any other desirable way, to a thermostat 60 which is preferably in the form of a spiral coil that surrounds the lower end of the shaft 48 and has its lower end secured to the bottom of the shaft, the thermostat extending longitudinally of the shaft from the gear segment to the lower end of said shaft.

The means for securing the thermostat to the lower end of the shaft 40 is capable of adjustment in order to vary the force exerted by the thermostat on the shaft 40 for any given temperature when the temperature is low. This means includes a member or bracket 62 to which the lower end of the thermostat is riveted, as indicated in Fig. 2. A portion of the bracket is U-shaped in form, the lower arm of the U indicated by reference numeral 64 having an orifice therein through which the lower end of the shaft 48 passes, while the upper arm 08 of the U-shaped member is bifurcated and receives the shaft between the two forks thereof. The vertical portion 68 of the U-shaped member is provided with an orifice in which a set, screw is threaded so that the end of the screw engages the reduced portion I2 of the shaft 48 and may be tightened to secure the member 66 in any desired position with respect to the-shaft.

The gear segment 52 is provided with teeth '14 which engage teeth I6 formed on the exterior surface of the piston member I8 received within a cylinder 80 formed within the housing 08 and the piston is normally adapted to be held in the position shown in Fig. 5 by a spring 82, which is received in the cylinder between the end thereof and the piston which is partially hollow to embrace the spring. The piston slides within the cylinder due to the suction of the engine and under the influence of other forces as will be more particularly set forth hereinafter, but when it is held in any given position by the spring 82, or by any other means, a change in temperature will cause expansion or contraction of the thermostat and if the piston be stationary at this time, the gear segment 52 is held stationary so that this expansion or contraction of the thermostat will cause the free end thereof to move and to so rotate the shaft 40 which. through the flexible connection 42 previously described. will move the valve toward open or closed position, expansion of the thermostat due to a rise in temperature causing the valve to open and contraction of the thermostat having the reverse effect and causing the valve to close.

The suction-operated piston hereinafter referred to, under normal conditions when the engine is not running, is held in position at the left of the cylinder in which it slides by the spring 82. As soon as the engine starts to rotate when it is being turned by the starting motor during the cranking period and before the engine starts to run under its own power, suction is communicated to the cylinder in which the piston slides through the passage 04 which connects with a sump or chamber 00, indicated In dotted lines in Fig. 2, formed within the housing 00 and this in turn connects with a passage 00 also indicated in dotted lines in Fig. 2, which communicates with the carburetor intake passage Just posterior to the throttle valves I0 and I0. Through this series of passages the manimold vacuum is communicated to the cylinder 00 to the right of the piston II, as shown in Fig. 2, and any increase in such vacuum tends to move the piston to the right, while a decrease in vacuum tends to cause movement of the piston to the left.

The piston I0 is provided with a hollow extension 00 into which projects a rod 02 which extends through a closure member 04 secured in position at the end of the extension 00 in any suitable manner. The rod 02 has an enlarged head 06 secured thereto in any desirable manner, which slides within the extension 00 and has a loose it therein, while at its opposite end such rod is screwed into or otherwise secured to a solid piston 00 which is slidable within a cylinder I00 formed in the housing 00 directly opposite the cylinder 00. The gear teeth I6 hereinbefore referred to, are formed on the outer surface of the extension 00 of the hollow piston 00.

The rod 02 has formed thereon integrally or secured thereto in any suitable manner, a flange I02 which projects from the rod and between the piston is received the upper end I04 01' a spring arm I06, the lower end of which is coiled around a stud I00 secured in the wall by the arm II! provided with an ear IIJ which extends around the spring. The position of arm H2 is controlled by another spring II 6 which ts coiled around the stud I 08 and has end IIl engaging the carburetor housing Whirl its other end I20 engages an end I22 projecting from an arm I24, which is connected by a yoke piece with arm II2, the two arms and yoke forming an integral structure rotatable on the stud I00. The pressure of the spring end II 0 against the housing 00 reacts against end I22 through the other end I20 of the spring to hold the parts in the position shown, unless moved by means later described which will move the arm H2 in a clockwise dlrection, and will put tension on spring arm I04 to cause it to follow arm II2, as later described.

The cylinder I00 in which the piston slides is provided with a resilient closure member I20 and the cylinder I00 and piston 98 constitute a ment of the piston I0 and in this manner insures that the choke is not moved to its different positions too rapidly, the operation of these parts being more fully described later.

Attention is invited particularly to bhe fact that in the wall of the cylinder I00 there is provided a tapered slot I28 which regulates the resistance of the above described dash pot to the motion of the parts controlled thereby so that the dash pots resistance is less the further the piston 88 is moved to the right. In other words, the dash pot does not provide as great a resistance to movement of the parts as the choke valve approaches more open position and consequently the delay in its movement toward open position is reduced as the valve is opened progressively.

Cooperating with the mechanism just described to determine the position of rod 82 through the medium of the spring I04 is a cam I30, best shown in Fig. 2. This cam engages the roller I32 rotatably mounted on the end of the arm I24 and the cam is secured in any desirable manner to the shaft on which the throttles I8 and I8 are mounted. The arrangement is such that as the throttles are moved toward their open positions the cam is rotated counterclockwise and through its engagement with the roller I32 the arm I24 is moved clockwise. The action of this arm and arm H2 is such as to move arm II2 out of the way of spring ar-m I04 so that spring arm I04 at its upper end can move to the right. At pressure of the spring arm I04 on the flange I02 is increased so that it will move piston 18 to the right as later described and the tension of the spring I I8 is increased to restore the parts to normal when the cam is moved back to its original position. It will be obvious that a reverse motion or the throttle shaft would permit the roller I32 to move upwardly and cause the upper end of the spring I04 and other parts to be moved to theleft by spring I I8. At the same time the end oi spring arm I04 through its engagement with piston 88, moves the rod 82 and piston 18 to the left. to effect a closing movement of the choke valve the movement of the piston 18 by rod 82 is brought about by engagement of flange I02 with the projecting portion 80 of the piston 18. The actual movements which the rod 82 makes under various operating conditions will be hereinafter more fully described.

It will be noted that the cam has a relatively steep portion Ia which is effective to move the arm I24 downwardly very considerably during the first part of the opening movement of the throttle and an almost concentric portion I301: which engages the roller I82 during the latter part of the throttle opening for reasons which will be later set forth. The construction is such that almost all the movement of arm I24 is eifected during the first 40 degrees of throttle opening.

The gear segment 52 hereinbefore referred to and which is moved by the suction operated piston is limited in its movement in either direction depending upon the character of the mixture which is desired, so that the mixture which is formed by the carburetor can be varied in fuel ratio by means of this limiting oi. movement of the gear segment.v In order that this movement or the gear segment may be variably limited for changes of temperature, variation of fuel volatility, or for any other reason that may be found desirable, the segment has two stops I40 and I42 (see Fig. 3) formed thereon which are adapted to engage with an eccentric member l44 carried by a pin I48 which extends through an opening in the housing 88 and is provided at its outer end with a knob I48 while between the knob and the wall of the housing is a spring washer I80 which presses against the wall of said housing when the the same time the nut is tight engaging orifices I82 formed in the 18 wall of the housing which act as detents to hold the eccentric member I44 in any desired position of adjustment. The knob may be turned and the eccentric member rotated so as to variably limit the movement of the two stops I48 and I42 as such stops are rotated upon lateral movement of the piston 18. By variably positioning the eccentric member the degree of pressure of the thermostat on the choke valve to hold the latter open or closed would be varied and this would vary the amount of air admitted for any given suction eflect on the valve and so to this extent variably controls the mixture proportions for any setting of the eccentric member I44 and this setting of said eccentric member controls the richness of both cranking V and running mixture.

It will be 'noted that the flexible cable 42 through which the movement 0! the automatic control unit is transmitted to the choke valve, is surrounded by a rubber housing I for protection and to prevent dirt and the like from getting on the flexible cable.

Heat is communicated to the thermostat to bring the thermostat up to or toward engine temperature through a heater tube I62. This lower end oi the tube fits within a recess I84 formed in a boss I88 on the wall of the exhaust manifold 28 or on the hot spot as is found most desirable. The heater tube extends upwardly from the recess and surrounds a considerable portion of the thermostat forming an efllcient means for conducting heat hereto as the engine temperature rises. The heater tube may be a single tube, or it may be surrounded with an outer tube I83 which flts outside of this heater tube and if used would serve a double purpose; first, to give the heater tube some more air and thus increase the efllciency and second, to protect the heater tube covering, dirt, water, etc. from entering the housing and from contact with the thermostat.

The preceding portion of this specification relates to the construction of the control unit which operates the choke valve to regulate the mixture proportions. According to the present invention there is embodied in this same control unit a switch which controls the action of the engine starter and the operation of which is controlled by the position or the throttle valve. This switch mechanism is positioned within a housing indicated in its entirety by the reference numeral I10 and which is adapted to be secured at the right hand end of the cylinder 88 as shown best in Fig. 2. The housing is provided with proiecting ears I12 and I14 which are secured by machine screws I18 to the wall of the main unit housing 88 a gasket I18 being provided to form a tight Joint between the main housing and the supplemental switch housing I10. The switch comprises two contnts I80 and I82, contact I88 being supported by a spring arm I84 which is bent at right angles as indicated in Fig. 5 and is secured to the housing I10 by rivets I88 but insulated therefrom by washers I88 of insulating material. The contact I82 is supported by a contact arm I88 of relatively rigid material which is bent at right angles and that portion of such arm most distant from the contact is separated from the housing I10 by a washer of insulating material I82 and is secured in the housing by rivets I84, or in any other desirable way. Binding posts. I88 and I88 are provided, to which the wires leading from the starter control circuit to the switch formed by the contacts I80 and I82 were connected. This circuit will be more fully described hereinafter.

- I" that A spring 2 is received between the spring arm I and a screw 202 threaded in thehousing I'll. This spring tends to move the spring arm I in a direction to close the contacts I" and I02 and by removal of the screw 202, springs of different strength or length can be substituted to adjust the pressure exerted on the contact carrying arm I.

The operating means which control the opening and closing of the contacts ill and "2 in clude connections from the throttle and connections operable by engine suction, the joint eifect of which is to so control the contacts Ill and they cannot be closed except at such time as the engine is not running and after the throttle has been moved a predetermined distance toward its open position. Also the arrangement is such that the contacts cannot be opened during cranking of the engine, but will be held open at all times when the engine is operating no matter how low the engine speed.

In order that the throttle in its movement may control the action of these contacts, an'arna 2" is secured to the throttle shalt by riveting such arm to the cam I", or in any other suitable way. This arm 2 carries a projecting lip or lug 2|! which is adapted to engage a rod 2 slidable in a bore in the wall of the main'housing II and having a reduced end 2i. which is designed to contact with the spring arm III to which the movable contact Jill is secured. The construction oi the arm 2 and the length of the rod 2" are such that when the throttle is in fully closed position, as shownin Fig. 5, the rod occupies-a position far enough to the right to hold the contact ill out of engagement with the fixed contact I82 and in order for these contacts to close the throttle must move toward open position approximately 30 or more degrees.

The means which is controlled by engine suction for operating or controlling the switch com prising contacts I and "2 consists primarily in a cam 2i2 which is rotatably mounted on a stud 2H secured in the wall 01' the housing I'll. Projecting from the cam is an arm 2i! to which is pivotally connected a link 2Il, the other end of which is pivotally connected formed on an angle-shaped member 222 which is secured by a rivet 224 to a diaphragm 228 the outer edge of which is secured between a flange 22. projecting from a cup-shaped metal shell 2" and a cooperating flange 222 formed on the housing I10. The edge of the shell 2 is crimped or spun around the flange 222 as indicated in Pig. 4 of the drawings to hold the diaphragm tightly between the flanges 22! and 232 and form a leak-proof joint. Washers 234 and 2 are provided on opposite sides of the diaphragm and are held in assembled position II the rivet 224 previously referred to. The washer 22. engages a spring 238 which is received between such washer and a shoulder 240 formed on the inside of the housing I10, said spring being adapted to hold the diaphragm in the position shown in Figs. 2 and 5, when there is no suction effective on such diaphragm or when the suction which is effective thereon is insufllcient to overcome the pressure of the spring.

Suction is communicated to the interior of the housing I10 through the opening 242 which registers with the cylinder it when the housing I'll 'is assembled in position on the housing II, as shown in Fig. 3 of the drawings.

It willbe apparent from consideration I Fig. that the spring arm I, which carries contact to an ear 22.v

scribed hereinafter.

I, has projecting therefrom a pin 2" and when the cam U2 is in such position that the highsurface thereon engages the pin 2", the contacts I" and "2 can never engage. The cam is moved to this podtion by the action 0! the engine suction. as will be more fully explained later and when it is in such position, it is prevented from returning to the position occupied in Pig. 5 so long as the pin 2" remains on the cam surface M2 by reason of a projecting toe or latching member 262 which extends beyond the periphery position which releases the pin 2|! from the latch moved by the "2 and allows them 2 to be spring 238 to the position shown drawings.

It is obvious from inl'igocithe inspection of Fig. 5 that the suction eflect on the diaphragm 220 will move the link 2i. upwardly to rotate the cam in a clockwise direction in order that the high surface may be brought opposite the pin 2. It is, however necessary that such rotation should not take place during the cranking of the engine because such movement of the cam would separate the contacts I and I82 and it it took place during cranking, the engine might not be started. are, therefore, provided to prevent the movement of the-cam in the manner described until the engine suction is higher than is ever possible when operating it at cranking The means for accomplishing this result comprises a spring detent which includes the spring pressed ball 2" which engages an orifice or depression 2" in a sleeve 2" which is secured to the cam M2 and surrounds the stud 2. This sleeve is rotated with the cam and the spring held ball exerts suilicient pressure against its out to prevent any rotary motion of the sleeve until the vacuum becomes higher than is ever produced when the engine is rotated by the starting motor during cranking. In fact the spring which holds the ball 2" in engagement with its seat in the sleeve 2" is of suiiicient strength to prevent any rotary movement of the sleeve until a vacuum of 8 to 6 inches of mercury is reached. The operation of this control switch during various engine operating conditions will be more fully de- In view of the provision of this detent arrangement a very light diaphragm spring can be employed and so light a spring is used that a suction of y," of mercury is enough to hold the switch open against the pressure of such spring. This prevents any possible closing of the switches as long as the engine is running under any possible operating condition.

In Fig. 7 of the drawings there is provided a diagrammatic view showing the control switch. the connections from the accelerator pedal to operate the throttle and the circuit of a preferred form of control device for the starting motor with whichthe control switch previously described is adapted to cooperate.

Referring to this figure, the starting motor is indicated at 2 and is provided with a shaft is indicated at 264. This assembly includes a sleeve 266 which is splined to the motor shaft pinion is adapted to be moved to theright to its gear meshing position by a lever 212 pivotally supported at 214 and the lower end of which engages a collar 216 slidabie on the sleeve 266 and adapted to be held in the position shown by a coil spring 216 which is received between the collar and the clutch. When the lever 212 is moved in a counterclockwise direction it tends to move the entire driving assembly to the right sufilciently for the pinion 216 to be meshed with the gear 264 and if the teeth of the pinion and gear are so positioned that the pinion can slide into gear without abutment of the teeth, the assembly will be so moved. If, however, the pinion teeth abut those of the .gear 264, the motion of the pinion to the right will be stopped but the lever will continue to move compressing the spring 216.

At the upper end the lever is connected to the armature 266 of a magnet which must be energired to move the lever 212 and at the opposite end the armature is provided with an enlarged head 282 which engages the movable contact 264 of the main starter switch which comprises in addition fixed contacts 266 and 286 and is normally held open by the pressure of a spring 266. When the motion of the lever 212 as described, is effective to move the movable contact 264 into engagement with contacts 266 and 266, the circuit of the starting motor is closed and the shaft 262 thereof is rotated. This rotation of the shaft will move the pinion 216 sufilciently to relieve the condition of tooth abutment above referred to and the spring 216 being collapsed and under pressure will immediately force the pinion into engagement with the engine gear 264.

The driving mechanism with the exception of the pinion shifting means, above described is not a portion of this invention in its detailed construction and is substantially what has been in public use for many years. While the magnet above referred to is not shown as of the same detailed construction as what has been in use for some years on the Buick and other automo-' biles, the identical magnet which has been so used can be used in place of that shown in the drawings, the only purpose of this disclosure beeffected as has previously been stated, by the action of a magnet having the armature 286. The magnet is provided with a winding designated by the number 6I6 which is grounded through the connection 6I2 and through the wire 6 is connected to the bolt I64 which secures the fixed contact I62 in position. The spring arm I84, as stated previously, is held in position by bolt I66 and to this bolt is connected the wire 6I6 leading from the fixed contact 626 of the ignition switch to the ignition system. The ignition switch is provided with a movable contact 622 which is connected by wire 624 to the wire 264 which has previously been described as extending to the battery. Obviously, when the contacts I66 and I62 are in engagement, current will A flow from the-battery through wire 264, wire 624,

ing illustrative, and is purely diagrammatic, the

details of the magnet being entirely unimportant so far as this invention is concerned.

The starting motor switch previously referred to is in circuit with a battery indicated at 262, the fixed contact 266 being connected by the lead 264 to the battery and is grounded through the connection 266. The other contact 266 of the starting motor switch is connected by the wire 266 to the commutator of the starting motor and is grounded through the connection 666. Obviously, when thecontact 264 engages the contacts 266 and 266 current will pass from the battery through the lead 264, the switch comprising contacts above referred to, lead 266 to the starting motor and through the connection 666 to ground from which it will pass through connection 266'to the battery.

The closing of the above described switch is the ignition switch, wire 6I6 and wire 6I6 to the movable contact I86. thence through the fixed contact I62 when such switch is closed, to the bolt I64 and through the wire 6I4 to the winding 6I6 and thence to ground through the connection 6I2. The closing of the ignition switch at any tim that the control switch comprising contacts I66 and I62 are closed, will, therefore, cause energization of the magnet and the motion of the armature 286 to the left with the result that the pinion 216 is placed in driving relation with the gear 264 and the main starting motor switch comprising contacts 264, 266 and 286 is closed to complete the circuit of the starting motor and cause the latter to operate. If either the ignition switch or the switch comprising contacts I66 and I62 be open, the circuit of th starting motor cannot be closed and the switch comprising contacts I86 and I62 is always maintained in an open condition during operation of the en ine under its own power so that the starting motor can never be rendered operative while the engine is running.

The generator charging circuit comprises the wire 264 which leads to the battery and the wire 626 is connected therewith and extends to the generator 626 which is connected to ground through the connection 666. The usual cut-out relay is indicated at 662.

Operation So far as the operation of that portion of the unit which controls the operation of th choke valve is concerned, the operation is not greatly different from the choke operating mechanism used on the 1937 Buick automobile, as the construction of the device herein disclosed is not greatly difierent from that one, the essentials of construction being the same and differing only in certain details. 7

If it be assumed that th engine is at rest and cold, with the throttle in closed position, the piston 16 is in its left hand position, as shown in Fig. 5, having been moved to that position by the cooperative action of the spring 62 and the thermostat 66, which upon contraction moves the piston to the left until its motion is stopped by engagement of the eccentric member I44 with its cooperating stop. With parts in this position, the choke valve is held closed by a force which varies inversely as the temperature. However, since the thermostat is held at one end by the spring 62 through the rack and segmental gear 16 and 14, the force exerted on such valve is no greater than the strength of spring 62 in its extended position.

When the starting motor circuit is closed and purpose of rotating the engine in order to start it, said engine rotation creates suction or a partial vacuum in the intake manifold which is communicated to the cylinder to the right of piston 18. Due to the slow rotation of the engine at this time, however, the suction created is insuflicient to overcome the forces holding the piston to the left and if the engine failed to start and the cranking period were prolonged, the engine would be flooded unless means were provided to prevent such action. Such a means is provided and is operable by the throttle to open the choke valve during cranking if this be found necessary.

To accomplish this result, the throttle operates the cam I 30 to swing the arm I downwardly so as to move arm II2 out of the path of spring I04 to permit such spring to move to the right every time the throttle is opened. The spring I04 is stronger than spring 02, but exerts no force to move piston 18 to the right when the parts are in the position shown in Fig. 2, because of the action of spring Hi. When the throttle opens, however, the pressure of the yoke on the opposite end of spring I04 builds up the pressure of such spring as arm H2 is moved out of the path thereof, so that the pressure exerted thereby on the piston is considerably greater than the pressure of spring 82. This action will move the rod 92, the piston 18, and in fact the whole assembly to the right as rapidly as th dash pot piston 00 will allow such action to take place. The retarding effect of the dash pot is, therefore, diminished as the piston is moved to the right by reason of the tapered slot. Obviously, if flooding occurs in the event of prolonged cranking, all that it is necessary to do is open the throttle which, through the medium of connections referred to, brings about a delayed opening movement of the choke valve. The throttle may then be closed and the cranking operation continued until the engine starts.

With the present construction, the throttle must be moved to a. partly open position in order to start the engine for the reason that the switch contacts I00 and I82 cannot engage until the throttle reaches such position. There is, however. so much lost motion between the flange I02 and the extension 90 of piston that the throttle can be moved to the position necessary for the switch to close without the accompanying movement of the rod causing any opening of the choke valve.

When the engine starts to run under its own power, the suction effective on the piston 10 greatly increases, as well as the flow of air through the carburetor which is eifective on the unbalanced choke valve and these forces are enough to overcome the pressure exerted by spring 02 and the resistance of the dash pot to effect opening of the choke valve to a position determined by the suction and air flow. The action of the dash pot piston 98, however, retards the movement of the piston and thus prevents too rapid opening movement of the choke valve, or movement of the valve too far toward open position, in this way preventing the admission of sufficient air to lean the mixture to an undesirable extent when the engine is operating under its own power during the warm up period.

If, after the engine is operating under its own power, the throttle be opened to accelerate the engine, the spring arm I04 and the dash pot piston 88 cooperate to provide a mixture of proper proportions during thisperiod, but it is not desirable that the mixture be enriched 0 8 t caus loading. Whenever the throttle is opened, the suction is reduced and the spring 02 tends to force the piston toward the left to effect a closing movement of the choke valve. This closing movement of the choke valve is controlled by the action of the dash pot and the spring arm I.

With the structure disclosed, if it be assumed that the engine is operating at relatively low speed with but slightly open throttle, the piston 10 stands somewhat to the right and the flange I02 may be a considerable distance from the extension 00 of piston I0. When the throttle is opened the suction effective on the piston 10 immediately drops with the result that the spring 02 moves the piston toward the left to effect closing of the choke valve. This movement will be rapid until the extension 90 strikes the flange I02 when it will be stopped by the pressure of sprin arm I04. Also after the extension 00 engages the flange I02, the assembly including the piston will be moved back toward the right as the throttle continues toward open position so that the closing movement of the choke valve is only temporary. Thus the first action occurring upon opening movement of the throttle is a closing of the choke valve, followed by a second action which is an opening of the valve due to the opening movement of the throttle which rotates cam I00, increasing the force of spring arm I04 and moving the piston 10 toward the right against the pressure of spring 0!, to again move the choke valve toward open position. This action permits the choke valve to assume a position where it is in a condition of balance, as determined by the several springs operating thereon, the force of the thermostat and engine suction and prevents too great enrichment of the mixture upon acceleration.

It will also be understood that ii the throttle be opened for acceleration after it has reached a position where the surface I'l0b of arm I10 is engaged by its cooperating roller there will be substantially no temporary closing oi the choke for acceleration purposes because the flange I02 will, under such conditions, have been moved into engagement with extension of piston I0 and, therefore, a drop in suction following the opening of the throttle will not be effective to move the piston to the left. Moreover, the further movement 01' the throttle toward open position does not cause any considerable movement of the piston to the right, because of the nearly concentric shape 0b of the cam I30. The above described action is desirable because after a predetermined throttle opening is reached, temporary closing of the choke valve for acceleration purposes is substantially unnecessary.

It will be understood that the rate of movement of the piston 10 toward the right, and consequently the rate of movement of the choke toward open position will be determined by the movement of the dash pot piston 98 toward the right, and it will also be apparent that the retarding eil'ect of such dash pot piston will be progressively reduced as said piston moves toward the right. It is not necessary to retard the opening movement of the choke to as great a degree when said valve approaches its open position as when said valve is more nearly closed. This control of the retarding eifect of the dash pot is brought about by the tapered slot previously described, which is formed in the wall of the dash pot cylinder I00.

It w ll also be apparent that the dash pot conshift the driving pinion into trols the movement to the left of piston 18 when the throttle is closed from an open position as the return spring can return the parts no more rapidly than the dash pot permits.

Coming now to the operation of the control switch by means of which the action of the starting motor is automatically regulated, it is obvious from consideration of the circuit diagram in Fig. 7, that the ignition switch and the switch comprising contacts I80 and I" must be closed and whenever the ignition switch or the control switch is open, the starting motor circuit is broken. When the engine is at rest, with the throttle closed, the ignition switch is open and also the control is open because the closing of the throttle through the medium of the arm extending from cam I30 moves the rod operated thereby so far to the right arm I84 so far to the right that the control switch is open. Under these conditions the suction operated latch is in the position shown in Fig. 5.

To start the engine, assuming the throttle is closed and the ignition turned off, it is necessary to close the ignition switch since this switch is in series in the starter control circuit and also to move the throttle sufiloiently toward open position to permit the rod 208 to move to the left enough to cause the control switch embodying contacts I80 and I82 to close. This movement of the throttle is approximately 35 or thereabouts toward open position, which has been found desirable to provide the desired quantity of mixture for starting purposes. The closing of the ignition switch and the closing of the control switch as described, complete the control circuit with the result that the magnet is operated to engagement with flywheel gear and at the same time close the main starting motor circuit, as previously described. The starter motor becomes operative then and will start the engine. As earlier pointed out, if the engine does not start promptly and the cranking period is prolonged without results, the operator should open the throttle for the purpose of relieving flooding, as previously described.

When the engine starts to run under its own power; the action of the engine suction is such as to move the high surface of the control cam into engagement with the pin on spring arm I84 to open the control switch and break the starter circuit when the starter will become inoperative. As long as the engine suction remains relatively high, the control cam will be :held in such position that the high surface is opposite the pin on that it pushes the spring] The spring detent which controls the operation of the cam and the latch member is an important feature of this invention and makes it substantially impossible for the control switch to be closed under any operating conditions which can be met. It is obviously necessary that a device of this character must be constructed so that the control switch cannot be opened during engine cranking or else the starter circuit would be broken and the engine would not be started. Due to the fact that the throttle is generally in only a partly open position during cranking, the suction may be higher when the engine is being turned by the tarting motor for the purpose of starting it than when it is operating under its own power with a relatively open throttle and heavy load. It has been found necessary to provide a device which will not 1 open during cranking under a suction of from cranking suction.

the spring arm I which is adapted to engage such cam surface and will hold the switch open. If, however, the engine is operating under heavy load with wide open throttle, the suction would drop and if means were not provided to prevent such action, it might be possible to close the starting motor circuit and cause serious damage to the starting system. This action is prevented by means of a latch member which is carried by the cam and which engages the pin on the spring arm I84 to prevent a return of the control com to its original position until the throttle has been allowed to close so as to move the pin out of the path of the latch member. Of course, if the throttle is closed, the suction immediately becomes high and the cam will not be permitted to move to a position where the control switch can be closed because of the high suction. If the throttle is again opened so that the suction drops, the latch will become again effective.

3 inches of mercury, but will hold open during operation at a suction much lower than that. The spring detent hereinbefore described, produces these results and because of the engagement of the spring-held ball with the cam member, the cam cannot be moved by engine suction until a vacuum of some 3% inches of mercury is reached, but after the ball is disengaged from the recess in which it normally seats in the cam chamber, the cam will be held by a suction of as little as a half an inch of mercury in its position where it will hold the switch open. This feature of operation is of considerable importance because even when operating under a part throttle condition where the vacuum would normally be high enough to hold th control switch open, under such conditions the throttle might be in a position that the rod 208 does not hold the switch open, the operator might increase the load by stepping on the brake for some purpose, in which event the engine would slow down and the suction drop off to a point less than the However, with the construction shown there i= always under all conditions ufilcient vacuum to hold the control switch open.

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. In a starting apparatus for internal combustion engines having a starting motor, a current source, a circuit for connecting said motor and current source, a control switch for controlling said circuit, means operable by engine suction for preventing the closing of said switch while the engine is self-operative, resilient means engaging said suction operated means when the switch is closed and exertin a force to prevent operation of said suction operated means, which is appreciably greater than the force exerted on said means by engine suction during rotation of the engine by the starting motor but less than the force exerted by engine suction when the engine becomes self -operative.

2. In a starting apparatus f0! internal combustion engines having a current source, a starting motor operable by current from said source and a circuit for connecting said starting motor with the current source, aswitch for controlling said circuit, means for operating said switch, a control member movable to two positions in one of which it prevents closing of th switch and in the other of which it permits said switch to be closed to cause operation of the starting motor,

means operable by the engine when it becomes self-operative to mov said control member to a position where it prevents closing of the switch, and means engaging said control member for preventing such movement of said control memher while the engine is being operated by the starting motor, said last named means being ineffective to prevent such movement of said control member whenever the engine begins to operate under it own poweri 3. In a starting apparatus for internal cmbustion engines having a current source, a starting motor operable by current from said source and a circuit for connecting said starting motor with the current source, a switch for controlling said circuit, means for operating said switch, a control member movable to two position in one of which it prevents closing of the switch and in the other of which it permits said switch to be closed. to cause operation of the starting motor, means operable by engine suction when the engine begins to run under its own power to move said control member to a position where it prevents closing of the switch, and means engaging said control member for preventing such movement of the control member while the engine is being operated by the starting motor, said engaging means being ineiiective to prevent movement of the control member whenever the engine becomes self operative.

4. In a starting apparatus for internal combustion engines having a current source, a start ing motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for controlling said circuit and provided with a plurality of contact members, a control member movable by engine suction to a position to prevent closing of the switch when the engine becomes selfoperative, means engaging said control member to hold it in position to prevent closing 0!, the switch as long as the engine is self-operative and manually operable means eilfeetive when moved in one direction to disengage said last named means from the control member to permit the latter to return to its normal inoperative position when the engine is not running in order to permit closing of the switch and effective when moved in the other direction to cause said switch to be closed in order to render the starting motor operative.

5. In a starting apparatus for inte al ombustion engines having a current source, i ing motor operable by current from said source and a circuit for connecting the star motor with said current source, a switch for controlling said circuit and provided with a plurality of contact members, a control member movabie by engine suction to a position to prevent closing of the switch when the engine becomes operative, a latch forv engaging the surface of the control member when said member has been moved by engine suction to the position it occupies when the switch is held open, to maintain said control member in such position as long as the engine is self operative, and manual means for disengaging the latch from the control mem-- her to permit the control member to return to its normal inoperative position when the engine becomes inoperative, so that the switch may be closed to start said engine.

6. In a starting apparatus for internal cornbustion engines havin a current source, a starting motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for controlling said circuit and provided with a plurality of contact members, a control member movable by engine suction and having a cam formed thereon with one abrupt face, said control member being moved to a position where the cam prevents closing of the switch, and a latch member for engaging the abrupt face of the cam to hold the control member in position to prevent closing of the switch as long as the engine is self-operative, and manual means for effecting release of the cam from the latch to permit return of the control member to normal position.

7. In a starting apparatus for internal combustion engines having a current source, a starting motor operable by current from said source and a circuit for connectin the starting motor with said current source, a switch for controlling said circuit and provided with a plurality 0! contact members, a control member movable by engine suction to a position to prevent closing of the switch when the engine becomes self-opentive, means engaging said control member and effective to prevent movement of said control member by suction during operation of the engine by the starting motor, but ineilective to prevent movement of said control member by auction when the engine becomes self-operative, and a second means eflective to hold the control memto which it is moved by engine suction as long as the engine is self-operative, to prevent any possible closing of the starting motor circuit while the engine is running under its own power.

8. In a starting apparatus for internal combustion engines havin a, current source, a starting motor operable by current from said source and a circuit for connecting the starting motor with said current source, a, switch for controlling said circuit and provided with a plurality of contact members, a control member movable by engine suction to a position to prevent closing of the switch when the engine becomes self-operative, means engaging said control member and effective to prevent movement of said control member by suction during operation of the enmotor, but inerfective to presaid control member by sucticn when the engine becomes self-operative, and a latch adapted to directly engage the control member to hold said member in the position to which it is moved by engine suction as long as the engine is self-operative to prevent any possible closin of the starting motor circuit while the engine is running under its own power.

9, In a, starting apparatus for internal coming motor circuit while the engine is running under its own power, and manual means for disabling said last named means so as to permit the control member to return to the position from which it is moved by engine suction.

10. In a starting apparatus for internal combustion engines having a current source, a starting motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for controlling said circuit and provided with a plurality of 0011- tact members, a control member movable by engine suction to a position to prevent closing of the switch when the engine becomes selfoperativ means engaging said control member and effective to prevent movement of said control member by suction during operation of the engine by the starting motor, but ineffective to prevent movement of said control member by suction when the engine becomes self-operative, a latch adapted to directly engage the control member to hold said member in the position to which it is moved by engine suction as long as the engine is self-operative to prevent any possible closing of the starting motor circuit while the engine is running under its own power, and manual means for disengaging the latch so as to permit the control member to return to the position from which it is moved by engine suction.

11. In a starting apparatus for internal combustion engines having a current source, a starting motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for controlling said circuit and provided with fixed and movable contact members, a control member engaging said movable contact and movable by engine suction to a position to prevent movement of the contact to a position to close the switch when the engine becomes self-operative, and means whereby the movable contact is effective to hold the control member in position to prevent closing of the switch as long as the engine is self-operative. v

12. In a starting apparatus for internal combustion engines having a current source, a starting motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for controlling said circuit and provided with fixed and movable contact members, a control member engaging said movable contact and movable by engine suction to a position to prevent movement of the contact to a position to close the switch when the engine becomes self-operative, means whereby the movable contact is efl'ective to hold the control member in position to prevent closing of the switch as long as the engine is self-operative and manual means eiIective to release the control member from said movable contact in order to permit said control member to return to the position from which it is moved by engine suction.

13. In a starting apparatus for internal combustion engines having a current source, a starting motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for control ing said circuit and provided with fixed and movable contact members, a control member movable by engine suction to a position to prevent closing of the switch when the engine becomes solioperative, means engaging said control member bustion engines having a current source, I

in position to prevent closing of the long asthe engine is self-operative.

14. In a starting apparatus for inte nal core ta i ing motor operable by current from said 5 and a circuit for connecting the starting rm with said current source, a switch for cont ling said circuit and provided with and movable contact members, a control member able by engine suction to a position to prevent closing of the switch when the engine becomes self-operative, means engaging said control member and effective to prevent movement thereof by suction during operation of the engine by the starting motor, means whereby'the movable contact is eifective to hold the control member in position to prevent closing of the switch as long as the engine is self-operative, and manual means for rendering the movable contact inefiective to hold the control member in position to prevent closing or the switch in order to permit the control member to return to the position from which it was moved by engine suction.

15. In a starting apparatus for internal combustion engines having a current source, a start ing motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for controlling said circuit and provided with fixed and movable contact members, a control member engaging said movable contact and movable by engine suction to a position to prevent movement of the movable contact to a position to close the switch when the engine becomes self-operative, said control member having a surface thereon adapted to be engaged by said movable contact when the control member is moved to a position to hold the switch open so as to hold the control memher in such position, and another means engag ging the control member and eiIective to prevent movement of said control member when the engine is operated by the starting motor.

16. In a starting apparatus for internal combustion engines having a current source, a starting motor operable by current from said source and a circuit for connecting the starting motor with said current source, a switch for controlling said circuit and provided with fixed and movable contact members, a control member engaging said movable contact and movable by engine suction to a position to prevent movement of the movable contact to a position to close the switch when the engine becomes self-operative, said control member having a surface thereon adapted to be engaged by said movable contact when the control member is moved to a position to hold the switch open so as to hold the control member in such position, another means engaging the control member and effective to prevent movement of said control member when the engine is operated by the starting motor, and manual means operable to disengage the movable contact from said surface so as to permit the control member to return to the position from which it is moved by engine suction.

CLARENCE H. JORGENBEN.

LAWRENCE C. DERMOND'

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