US2034745A - Throttle control mechanism - Google Patents

Description

March 24, 1936. 3 CUMMINS 2,034,745

THROTTLE CONTROL MECHANISM Original Filed Oct. 26, 1954 Patented Mar. 24, 1936 UNHTED STATES 2,034,745 THROTTLE CONTROL MECHANISM Clessie L. Cummins, Columbus, Ind., assignor to Oil Engine Development Company, Columbus,

Ind., a, corporation of Indiana Original application October 26, 1934, Serial No.

750,127. Divided and 1935, Serial No. 28,908

this application June 28,

2 Claims. (01. 105-48) My invention relates to a throttle control mechanism for internal combustion engines, particularly oil engines, and is concerned primarily with a mechanism for preventing the movement of the throttle to full open position until the vehicle propelled, or generally the load moved, thereby has attained a. predetermined speed.

This application is a division of my copending application for a throttle control mechanism, Serial No. 750,127, filed October 26, 1934.

It is characteristic of oil engines that practically their full power is available when starting under load. This condition is advantageous where the principal operative requirement is rapid acceleration, but is a positive detriment unless properly controlled where, for example, the engine furnishes the motive power for a shifting locomotive in a railroad yard. Because of the high starting torque of the engine, the tendency of the shifting crew is to couple as many cars as the locomotive is capable of moving from a standing start, with the result that the train cannot be accelerated and therefore is moved at a slower rate of speed than is demanded by efficient shifting service.

It is therefore desirable to provide a mechanism which prevents the utilization of the full power of the engine when starting under load by interposing a stop in the path of movement of the throttle lever short of the latters full load position, and which is automatically shifted to a clear position when the locomotive, for example, attains a predetermined speed, and further, in which the relation between the stop and throttle lever is such that the latter may be moved from full-load to no-load position, notwithstanding that the stop may then be occupying an interrupting position due to a decrease in the train speed.

The principal object of the present invention is to devise a mechanism having the above characteristic which is adapted for operation by one of the power sources that are customarily available on track vehicles, for example, namely, electricity that is ordinarily employed for lighting, or

other auxiliary functions.

These and further objects of my invention will be set forth in the following specification, reference being had to the accompanying drawing, and the novel means by which said objects are eifectuated will be definitely pointed out in the claims.

In the drawing, the figure is a diagrammatic view, partly in section, showing a mechanically controlled, electric circuit for limiting the movement of the throttle lever towards full-load position, the lever being shown in the maximum position which it may assume until the locomitive attains a predetermined speed.

Referring to the drawing, the numeral l designates the wheel of a locomotive, for example, which is mounted on the usual axle ll that may have affixed thereto a pulley l2. A belt l3 operates over the pulley I 2 and also over a second pulley I l secured to a shaft l5 which is journaled in a suitable bearing I 6. The shaft l5 extends to the left of the bearing and has afiixed thereto a pair of arms I! upon which are pivotally mounted a pair of fly-ball levers I8, the inner arms IQ of which are in constant bearing engagement with one end of a sleeve 2!] that is journaled upon an extension 2! of the shaft l5. The left end of the sleeve is formed with an annular channel 22 and a coil spring 23, which encircles the left extremity of the extension 2|, bears against the left end of the sleeve and also against the head 24 provided on the extension 2!. The tendency of the spring 23 to extend in length causes the sleeve 20 to bear constantly against the lever arms l9. a

A rock lever 25 is pivoted at 26 upon a convenient supporting structure and the upper end of the lever is formed as a nose for constant retention in the annular channel 22. The lever may also carry an electrical contact 21 which is adapted. to bear against a second contact 28 that is connected by a lead 29 to one end of a solenoid coil 30. The contact 2'! is connected to the opposite' end of this coil by a lead 3!, a source of electrical energy 32, and a second lead 33.

A magnetic core 34 is slidably mounted within the solenoid and is provided with a stop 35 which is normally actuated outwardly by a coil spring 36 to an interrupting position with the lower end of a throttle lever 31 that is pivoted as at 38. The no-load position of the throttle lever is indicated by the dotted line 39 and the full-load position thereof by the dotted line 40, the lever being shown in the maximum position to which it can be moved owing to its engagement with the stop 35. Preferably, the lower end of the lever 31 and the upper end of the stop 35 are provided with inclined cam surfaces M and 42, respectively, so that the throttle lever can be returned to the no-load position from any position between the intermediate position, as shown, and the full-load position, notwithstanding that the stop 28 may be occupying the position shown in the figure. A situation of this kind might occur, for example, when the locomotive 2 is ascending a grade with the throttle lever in full-load position and it is desired to bring the train to a stop. During this return movement, it will be obvious that the cam surfaces will cause the stop to be moved downwardly in the coil until the lever 31 has clearedthe upper end of the stop.

In the relation of the parts as shown, the interrupting position of the stop 35 is indicated as permitting a movement of the throttle lever through approximately twothirds of its range from the no-load position, although this relation may be varied as desired. In the operation of this mechanism, the fly-balls ill will be adjusted so that, at some predetermined speed of the locomotive, they will move outwardly sufficiently to cause the sliding of the sleeve 23 toward the left and consequently a closing of the contacts 21 and 28 to thereby complete the electrical circuit which includes the solenoid coil 30. The magnetic condition thereby established around the core 34 draws the latter downwardly against the spring 36 until the stop 35 has reached a position clear of the lower end of the throttle lever. This releasing movement of the fly-balls may be set for as low as a speed of five miles per hour, or at any speed at which the operating requirementsdemand. When the speed of the locomotive falls below the indicated critical speed, the stop will be returned to interrupting position by the spring 36, since the electric circuit is then broken. 7

It will be obvious that the rock arm 25 may possess other mechanical conformations than that shown, since the generic construction involved is the closing of an electric circuit by a mechanical governor device that is responsive to the speed of the vehicle.

It is apparent that the shifting crew is positively prevented from coupling more cars to the locomotive than the latter can initially move for the throttle opening indicated. Therefore, there is always provided a sufficient reserve of power to insure a desirable acceleration of the coupled train and it is contemplated that, after the mechanism is once adjusted, it will be incapable of unauthorized change by the train crew. Moreover, the mechanism is designed to make use of a source of power that is customarily available in railway service, so that no additional auxiliaries are required.

It is to be understood, however, that no restrictive interpretation is to be placed on the application of my mechanism to the field of railway service, in view of the above disclosure, since the essential conception involved is capable of other and broader uses in the art of engine controls. For example, in hoisting apparatus, crane or steam shovel installations and similar appliances, it may be desirable to arrange for a power reserve, such that the load which the engine could initially move would be restricted to a degree permitting. subsequent acceleration. The term vehicle, therefore, is employed in its broader aspect as being an instrument of conveyance.

I claim:

1. A throttle control mechanism for an engine driven vehicle comprising in combination, a throttle lever operable between no-load and fullload positions, a solenoid, a magnetic core operable in the solenoid and having a stop projecting externally thereof, means tending to hold the stop in a position to limit the movement of the lever to a predetermined intermediate position when moved towards full-load position, a mechanical governor device controlled by the speed of the vehicle, and an electrical circuit including the solenoid, a source of electrical energy, and means actuated by the governor device to close the circuit and cause a retraction of the magnetic core sufficient to free the throttle lever for continued movement toward full-load position when the vehicle attains a predetermined speed.

2. A throttle control mechanism for an engine driven vehicle comprising in combination, a

throttle lever operable between no-load and fullload positions, a solenoid, a magnetic core operable in the solenoid and having a stop projecting externally thereof, a spring tending to hold the stop in a position to limit the movement of the lever to a predetermined intermediate position when moved toward full-load position, a mechanical governor device controlled by the speed of the vehicle, a normally open electrical circuit including the solenoid and the source of electrical energy, and a switch arm moved by the governor device to close the circuit and cause a retraction of the magnetic core sufiicient to free the throttle lever for continued movement toward fullload position when the vehicle attains a predetermined speed.

CLESSIE L. CUMMINS.

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