US2315273A - Electric throttle control system - Google Patents

Description

March 30, 1943. O PUTT ELECTRIC THROTTLE CONTROL SYSTEM Filed Oct. 17, 1941 Fatentecl Mar. 3Q, 3943 PATENT OFFICE OTTLE CONTROL SYSTEM 6 Claims.

This invention relates to throttle control systems for internal combustion engine; and in particular, multi-engined aircraft, and has for its first objective the remote control of carburetor throttles by electrical means and spring tension.

Another object is to provide means whereby the various throttles of the various motors of a bombing plane are closed by electro-magnetic action and opened by spring tension, in a manner and for the purpose hereinafter described.

A further object is to provide operative means and apparatus, so connected to an electrical circuit, that a carburetor throttle, or a plurality of carburetor throttles, will be fully opened and held open by spring tension or the forces of gravity or inertia, or by both spring tension and gravity or inertia, in case of disruption of said circuit or circuits, or loss of electrical power.

I attain these and other advantages and objects of my invention by the mechanism illustrated in the accompanying drawingyin which- Figure 1 is a view partly in section and partly in side elevation of a carburetor with its throttlearm connected to its solenoid plunger in the deenergized position and showing th throttle-valve T in the full open position;

Fig.2 is a diagrammatic view of the circuit arrangement, showing connections'to the various controls and the battery; and also showing the various carburetor throttle arms connected to their respective solenoid plungers in the ener-- gized position and with all throttle valves in their closed position.

,It has been the practice of aviation companies to arrange the throttl control of their multimotored bombers and transport planes to function in the same manner that is employed on automobile and trucks; that is, the throttle is opened by manual effort and closed either by manual effort or spring tension.

In some cases this throttle control was effected through the medium of a system of rocker-shafts, bell-cranks and levers, similar to that employed on automobiles; while in recent practice, an elabrate and expensive hydraulic system is being employed, but in both cases the throttle is opened by manual effort or forces liberated by manual effort and closed by spring tension", or the same force that opened it.

Now assume that a two or four-motor bomber, with a throttle control system arranged to operate as above, was making a power dive toward some objective protected by anti-aircraft weapons, and a piece of shrapnel should sever or bend or otherwise damage the mechanical control shafting, cranks or levers, extending from the control cabin out to the motors on the wings, it might render one or more motors useless. In case of a hydraulic system, the rupture or puncture of the relatively long pipes or tubes carrying the fluid would immediately affect two or more motors, because fluid pressure would no longer be available to maintain throttle control or an open throttle. Thus, with either of these systems a condition would exist wherein the chance of motor failure would be increased at the most critical period, and contribute to or be the direct cause of the loss of the ship and its crew, because of the pilots inability to pull out of the-dive through loss of power.

In contradistinction to the above described systern of throttle control, my electric system functions in exactly the reverse manner, in that I provide means and power to force the throttles closed, or to their idling position, and provide spring tension and inertia to pull them open. Instead of shafting, rods or tubing extending from the control cabin out to the carburetor, I employ suitable electric wire or cable, which may be armored if desired, and which may be run in any desired manner or angle and requiring less space.

If the throttles are to be opened slightly, current is reduced proportionately and if 1111 .throttie is desired, current is cut oil entirely, hence it a bomber is equipped with my system of control and a piece of shrapnel should sever a wire leading to any of the solenoids at each carburetor, that throttle would assume a full open position, or if it was already open (which would be or might be the case during a power dive) then the severance of this wire or wires would have no effect on the motor it controlled. If the severance of this or any other control wire should cause a short circuit, then the fuses in those circuits would be blown and no harm result. Thus, the pilot would have that one chance of pulling out of the dive with full power and getting away, that he would not havewith either of the other systems of controlhereinbe'fore described.

With one or all motors on full throttle, due to severance of one or more control wires or circuits, or the destruction or injury of the battery or other source of power, the pilot could reduce his speed by cutting the magneto ignition to two or all motors to eiiect a safe landing speed.

Referring to the drawing in which like characters of reference designate like parts in each of the views, Figure 1 illustrates a carburetor I, partly in section, showing a throttle valve T, and valve arm 3. The latter is fulcrumed to the plunger rod 2 of the solenoid S. The lower hollow cylindrical extension i l of solenoid S is outside the magnetic field and is suitably fulcrumed at l. It is grounded as shown in Figs. 1 and 2. One end of a spring is suitably attached to the valve-arm 3 and the other end secured to the solenoid as shown, or to any other suitable fixed point. The solenoid is shown in Fig. 1 in its deenergized position with the throttle valve wide open. As shown, the solenoid is disposed in an upwardly slanting position, whereby gravity will tend to pull the plunger rod l2 downwardly and tend to open the throttle valve T. The solenoid S may be of any desired construction, but it is designed so that one end of its iron plunger 12 will normally rest just inside of the magnetic field of the coil Hi. When the magnetic coil i3 is energized, the plunger i2 will be drawn into the central portion of the coil against the tension of the spring 5 to close the throttle valve T, as shown in Fig. 2. One end of the solenoid winding I3 is grounded on the tube l l, while the winding and the other end thereof i5 is insulated from ground, in the conventional manner.

When the plunger is drawn into the solenoid when same is energized, a suction effect is created below the lower extremity of the plunger and this suction is relieved by the air that is drawn in through the upper open end of the tube M, past the plunger and into the lower internal extremity of the tube I4, thus preventing a slamming action of the valve T and providing a cushioning effect.

When solenoid is de-energized and the spring 5 pulls the plunger I2 back toward its lower position, the trapped air within the lower portion of the tube I4 is forced upward past the plunger l2 and out through the open end of the tube I4, thus providing for a cushioning effect in this direction of plunger movement. Thus, the action of the plunger is smooth and shockless in either direction of movement. The rapidity of movement of the plunger in either direction is predetermined by the amount or degree of clearance between the plunger and the tube i l. The less this clearance is, the greater the cushion effect and the slower will be the movement of the plunger. Increasing the clearance permits the air'to enter or escape with greater rapidity thus increasing the rapidity of plunger movement under the influence of electro-magnetic action or spring tension.

The diagrammatic view of the electrical circuits and associated devices electrically connected therewith is clearly indicated in Fig. 2. The electrical circuit is as follows:

Referring to Fig. 2, starting at the battery 6, one pole of the battery is preferably grounded. The other pole is connected to a suitable switch contact, so that when contact arm l of said switch is in the solid line position shown in Fig. 2, current will flow through said arm '3, thence .to one end of the resistance 8, thence through a rheostat or accelerator control arm 9, thence to one end of each of the adjustable compensating resistance units RI, R2, R3 and R 5, as shown, thence into each of the contact arms Hi, We, lfib and H10, thence through the fuses H, No, lib and lie to each of the solenoid terminal Wires l5, l5a, b and H30. Each of said solenoids is thus energized, causing their respective plungers to be drawn into the said solenoids to force each of the carburetor throttle valves to their idling or closed position, substantially as shown. All of the throttle valves are moved synor Or) chronously by means of the accelerator control arm 9 when the controls RI, R2, R3 and Rd are in their normal position as shown in the drawing (Fig.2).

Due to voltage drop in the different length circuits to the solenoids, the compensating re sistances or rheostats Rl, R2, R3, and R4 are adjusted to provide identical current input to each solenoid so that their field intensity will be the same. Each spring 5, 5a, 5b and 50 should be adjusted to an equal tension.

It will be observed that the throttle or accelerator resistance 8 is cut out" of the circuit at full closed throttle position, because the contact arm 9 is in contact with the same end of a resistance 5 that is connected direct to battery 6. Hence the full maximum current will flow through the contact arm 9 to each of the compensating resistances and thence to the several solenoid windings and to ground, thus holding the several carburetor throttles in their off or idling position; but if the accelerator arm 9 is depressed, more and more resistance will be introduced into the circuit which will cause the field intensity" of the respective solenoids to decrease proportionately and as this factor decreases, the springs 5, 5a, 5b and 50 will pull the throttle valves Tl, T2, T3 and T4 open proportionately, until, if the arm 9 is depressed to the dotted line position shown, the battery will be disconnected and all solenoids de-energized, thus permitting the springs 5, 5a. 5b and 50 to force all the said throttle valves to the full open position shown in Fig. l, by means of the above-described spring tension and gravitational effect on the plunger.

A sudden release of the accelerator-arm 9 will cause it to return to the solid line position shown. by means of the spring l6 or otherwise, thereby increasing the current volume to each of the said solenoids, the action of which would instantly force all of the throttle valves to the closed or idling position shown in Fig. 2. If the accelertor arm 9 is released gradually, then the solenoids would be energized gradually and the throttle valves would be moved in unison gradually to- Ward the idling position and thus gradually reducing the speed of all motors proportionately.

Each of the compensating rheostats RI R2, R3, and R5 are provided with isolated contacts ll, lla, Nb, and He, respectively whichare all connected together in parallel to the wire l8 which leads to and is connected with the discharge side of the battery & specifically as shown. Any or all of the rheostat contact arms Ill, 10a, lllb, and lilo may be moved to the extreme right out of contact with their respective resistances and into contact with the points H, Ha, ill) and lie respectively, thus permitting full current volume to flow directly to their respective solenoids, the action of which would energize same and cause the several throttles to be forced to their idling position regardless of the position of the accelerator control arm 9.

Now, assume that the pilot desired to idle the two motors on the left wing and accelerate the two motors on the right wing he would then turn rheostats R! and R2 to the extreme right, which action would fully energize the solenoids on the left wing carburetor and force their throttles to the idling position. At the same time he would depress the accelerator arm 9 the required degree to accelerate the two right wing motors, after which he would release the arm 9 to the normal position indicated in Fig. 2, and re-set the rheostats R! and R2. To accelerate the left wing motors and idle the right wing motors, he would turn rheostats R3 and Rd to the extreme right position and at the same time depress the accelerator arm 9 as before.

Any one or more of the motors may be idled and the others accelerated as desired by the proper manipulation of the rheostats RI, R2, R3

and R4 and the throttle control arm 9 as above ulated as desired to facilitate taxiing or maneuverability on the ground or in the air and after attaining the desired altitude, flight at full throttie with no current'consumption as respects the solenoids. Only during the warming up, idling, or part throttle operation is current consumed. The location of the solenoids close to the motors, obviates any chance of plungers sticking due to 4 moisture or ice, and all other equipment such as the compensating rheostats, accelerator control, fuses, switch and battery are located in the control cabin where they may be made easily accessi-ble.

It is to be noted, with the solenoids in the position shown and assuming that this view is toward the nose of the plane or direction of travel, that when pulling out of a dive, executing sharp turns, rolls or loops, requiring full throttle, the

forces of inertia act on the plungers in the same direction as that of the spring 5 to open the throttle and hold it open until less power is required.

The tension of this spring should be ample to insure the return of the plunger to its normal position when the solenoid is de-energized.

The cost of my electric throttle control system would be no more and probably much less than the cost of the hydraulic system now in use and the saving of the crew and one bombing plane through the safety factors incorporated in my invention, would pay for hundreds of these control systems.

What I claim is:

1. In an electriothrottle control system for internal combustion engines, the combination with a plurality of internal combustion engines, of a master control element, throttle valves for the carburetors of each of said engines, spring means operatively connected with each of said valves and normally holding the valves in open position, a solenoid for each of the valves, each solenoid having its plunger rod operatively connected with the respective valve and arranged to close same, and electric means connected with each of the aforesaid solenoids for independently operating same to permit of independent control of the closing of each of the valves by the solenoid plunger, and for combined and simultaneous control of all valves in unison by means of the master control element.

2. In an electric throttle control system for internal combustion engines, the combination with a plurality of internal combustion engines of the ,master control element throttle valves for the carburetors of said engines, independent spring means operatively connected with each of said valves and normally holding the valves in open position, a solenoid for and operatively connected with each valve and arranged to close same, and electric means connected with each of the aforesaid solenoids for independently operating same to permit of independent remote control of each of the said valves by the solenoid plunger and electrically controlled means for combined and simultaneous control of all valves synchronously by means of the master control element, each of thesolenoids having a hollow cylindrical extension for the plunger of the solenoid to protect same from ice and'snow, and act as a guide for the said plunger.

3. In an electric throttle control system for internal combustion engines, the combination with a plurality of internal combustion engines of throttle valves for the carburetors of said engines, independent spring means operatively connected with each of said valves and normally holding the valves in open position, a solenoid for and operatively connected with each valve and arranged to close'same, and electric means connected with each of the aforesaid solenoids for independently operating same to permit of independent remote control of each of the said valves by the solenoid plunger, a rheostat for combined and simultaneous control of all valves synchronously, said solenoids being disposed in a position whereby gravity will tend to pull the plungers downwardly and thereby tend to open the proper valves, whereby the throttle control valve will normally be held in open position.

4. In an electric throttle control system for internal combustion engines, the combination with a plurality of internal combustion engines of a master control element, throttle valves for the .carburetors of said engines, independent spring means operatively connected with each of said valves and normally holding the valves in open position, a solenoid for and operatively connected with each valve and arranged to close same, and electric means connected with each of the aforesaid solenoids for independently operating same to permit of independent remote control of each of the said valves by the solenoid, and for combined and simultaneous control of all valves in unison by means of the aforesaid master control element, plungers for forcing the throttles i to idling position by means of electric power and causing them to open gradually by reducing said power or to open instantly upon disruption of said electric power.

5. In an electric throttle control system for internal combustion engines, the combination with a plurality of internal combustion engines power, and causing them to open gradually by reducing said power or to open instantly upon dismption of said electric power, and rheostats for regulating current input to each of the solenoids, whereby they will cause the throttle valve'of all the engines to move in unison toward idlingposition when the solenoids are energized.

6,. In an electric throttle control system for kr ll power and causing them to open gradually by reducing said power or to open instantly upon disruption of said electric power, rheostats for regulating current input to each of the solenoids,

whereby they will cause the throttle valve 01' all the engines to move in unison toward the idling position when the solenoids are energized, each of they solenoids having a hollow cylindrical extension tor the plunger of the solenoids to protect same from ice and snow in high altitudes, and act as a guide for same.

, HARLIE O. PUTT.

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