USRE20824E - Freewheeling mechanism of motor - Google Patents

Description

A, 9, 1938. K, MAYBACH R15 20,824

FREEWHEELING MECHANISM 6F MOTOR CARS Original Filed June 20, 1933 Reissued Aug. 9, 193a rnsawmaanmo rgg msm or Moron Kai-1 Maybach, Frledrichshafen, Bodensce. Germany, assignor to Maybach-Motorenbau G. m. b. 11., Frledrlchshafen, Germany Original No. 2,034,263, dated March 17, 1936, Se-

rial No. 676,633, June 20, 1933. Application for reissue September 26, 1936, Serial No. 102,681. In Germany July 1. 1932 v 1: Claims. (01. lea-m) My invention relates to motor cars in which;

means are provided for temporarily disconnecting the motor from the driving wheels for the purpose of free-wheeling, especially when driving 5 on level roads or down hill. During such periods the speed bL the motor is automatically reduced to the lowestpossible minimum. so that the fuel ,consumption is also a minimum, and at the same time the working of the motor should be practically noiseless.

Generally there are auxiliary machines, such as dynamos and others, driven by the motor.

Some of these machines serve for feeding energy,

to storage elements, such as electric accumula 5 tors or accumulators for compressed air, or the like. During the free-wheeling periods of the motor car, when the motor runs with reduced speed, the amount of energy fed to the accumulators is also lower than during the time the motor is running at normal speed. Consequently the accumulators may in certain cases run short of energy, especially when the driver of the car has been free-wheeling for long periods. To avoid the very disagreeable consequences of *such 25 running short of energy necessary for certain purposes and in cases of emergency, it has been suggested to provide more powerful auxiliary machines for feeding the accumulators. But such more powerful machines are also larger, 30 heavier and more expensive, so that many disadvantages are connected therewith.

My invention gives a very simple yet effective solution for these conditions. I provide means which automatically alter the speed limit of the 35 motor when disconnected to a higher limit for the periods during which the car runs faster than a certain minimum speed, that is for the period during which energy from the accumulators may he wanted. Thus. during the freewheeling periods the motor has the lowest possible speed as long as the disconnected car in its speed runs below a certain limit, but as soon as the car exceeds this limit automaticall a higher speed is set for the disconnected motor.

45 Consequently, during this latter period the auxil- In other words, when the control means for the motor when disconnected, working in dependency of the motoritself, whichcauses the motor to run with a constant low speed. Then I have a second speed control means working in dependency of the speed of 5 the car; this second means does not control the speed of the motor directly, but simply acts on the first control means in such manner that the automatically controlled motor speed is raised to 1 another levelas soon as the car inits speed q exceeds a predeterminedlimit.

All this willbe understood best when having reference to, the drawing which represents an example embodying my invention.

The flgure is-a mere diagram showing invertical section the main elements of the mechanism.

The motor is indicated at M. Its crank shaft I by means of flexible shaft 2 drives the .fluid pump 3. Shaft I on the other side of friction clutch 21, 28 and in driving connection with the change speed gear and the driving wheels of the car (both not represented) by means-of flexible shaft 5 drives fluid pump 8.

Pump 3 sucks out of well I! and forces the fluid, oil for instance, into space I. There is an opening I controlled by screw 0 by means of which it is possible to determine the liquid pressure within space 'I which shall acton control member 39 sliding within cylinder 49 and being under the reaction of spring ll. Tube 23 com- 30 ing from the intake manifold of the motor M' connects to cylinder is and is adapted to create vacuum (from the intake manifold) within tube ll whenevercontrol member 39 is moved downward; whereas upward movement of member 39 connects tube II with the open air by means of opening I 2 in cylinder 49. Thus, control 'member 88 in accordance with the pressure prevailing in space I and following the slightest changes inthis pressure connects tube ll either with the 40 vacuum of manifold 24- or with the open air of aperture 12, or, when the pressure in space 1 and that of spring "I are equal it rests in its middle position. I

Tube I l is connected to cylinder l3 in'which 5 piston II is adapted to move up and down. One end of cylinder II is connected to the open air, whereas on the other side of piston ll the vacuum of tube ll may act against the reaction of spring I. Consequently, whenever tube II is connected to the vacuum of manifold 24 piston It moves upward so that piston r l6 pushes against lever l1 and thereby o s throttle ll.

D p I decreases'in revolutions so that the pressure in space 1 goes 5.

open throttle ll so that the motor, and with it pump 3, increases in speed again.

speed. which depends upon the setting of screws 0 and the features of spring l0. 8 ws l3 and II" serve for limiting the stroke of I: ll.

Oi course, throttle ll .can besid be moved at will by the driver by means of lever 20, rod 2| and lever 22, against the action of spring is. Pump 6, driven by shaft 4, in its speed depends upon the speed of the car. As long as the friction clutch 21, 2. is in engagement, both pumps, I and 6, rotate at equal speed; but when the car is de-clutched, for example by pushing down lever I or by means of vacuum as indicated at 2!, and when the'gas pedal is released, the motor automatically decreases in speed and comes to a constant low speed as explained above,

but pump 6 at the same time in its speed depends upon the speed of the car,,which may be comparatively higher depending upon the road conditions,

Pump 6 sucks out of space 32 which is in connection with well by means of aperture 3i Y controlled by screw Ill. Consequently, pump 8 when exceeding in speed a certain limit, which is controlled by setting screw 30, causes a certain decrease in pressure within space 32 thereby opening valve 31 against the reaction of spring 34 and also against the reaction of the liquid pressure within space I, because of valve 31 and connecting rod 36. The opening of valve 31 toautomatically controlled lowest motor speed.

vlBy means of screw the vehicle speed is set,

; at which the automatically controlled motor speed changes automatically. And the new higher automatically controlled motor speed is determined by adequately setting screw 38.

The first mentioned motor speed should be as low as circumstances allow. The speed limit for the car at which the automatically controlled v motor speed is altered may for example be at about 20 miles per hour. And the upper automatically controlled motor speed should be chosen in accordance with the prevailing conditions in every case.

I do not want to be limited to the details described or shown in the example, as many variations will occur to those skilled in the art.

What I claim is: 1. In a motor driven vehicle mechanism of the type described comprising: a member rotating independency of the motor speed, a member rotating in dependency of the car speed, a member v Thus, the motor, if left to itself. will come to a constant trolled idling speed of the motor to a higher limit as soon as the car speed exceeds a predetermined limit.

2.'In a motor driven vehicle in combination;

a first fluid pump driven. by the motor, a second fluid pump, driven by the car, a member for automatically controlling the fuel intake oithe motor, means for operating said member, said operating means being controlled by the pressure of the liquid pumped by said first pump, and a valve controlled by said second pump, said valve being adapted to alter the pressure of the liquid pumped by said first pump.

3. In a motor driven vehicle in combination the elements as claimed in claim 1, and further including: means for setting the automatically controlled low speed for themotor, means for setting the automatically controlled higher speed for the motor," and means for setting the car speed at which the automatically controlled motor speed is to change.

4. In a motor driven vehicle mechanism of the type described comprising: automatic speed controlling means for the motor causing a certain low idling speed and a device for temporarily raising saididling speed limit to a higher but constant level, said latter device working in de-' pendency of the car speed.

5. In a motor driven vehicle in combination: a first fluid pump driven by the motor, a second fluid pump driven by the car, a fluid pressure motor, a valve for controlling the pressure in said fluid pressure motor, said valve being influenced by the pressure of the liquid pumped by said first pump, a member for automatically controlling the fuel intake of the motor for driving the vehicle, said member being operated by said fluid pressure motor, and means adapted to alter the pressure of the liquid pumped by said first pump, said means being controlled by said second pump.' v

6. In a motor driven vehicle mechanism of the type described, means causing the motor when declutched to 11111 at a low idling speed as long as the vehicle speed does not exceed a predetermined limit, and means working in dependency on the vehicle speed and becoming automatically operative when at any time while the motor is declutched the vehicle speed is above the predeetgdrmined limit to increase the'motor idling sp 7. A motor drivenvehicle speed control mechanism operative during periods when the vehicle is in free-wheeling, and including, means'for causing the motor to run at a low idling speed, and a speed regulating device working in dependency on the vehicle speed operative to raise the idling speed of the motor when the vehicle speed increases, and operative to lower the idling speed of the motor when the vehicle speed decreases.

8. In a motor driven vehicle mechanism of the type described, means for setting the motor to run at a low idling speed, and a device becoming operative upon declutching of the motor and working in dependency on variations in the vehicle speed at any time during periods when the vehicle is free-wheeling to change the idling speed of the motor.

for varying motor speed between low and high idling rates, said regulating mechanism becoming operative when the motor is declutched and the minimum idling rate until the car speed is decreased to a predetermined limit.

11. The combination in a motor car of a. clutch,

a vehicle power shaft driven by the motor through the clutch, and regulating mechanism for the motor fuel supply working in dependency on the speed of said shaft during periods when the shaft is declutched and the vehicle and said shaft overrun the motor, said regulating mecha- 1 nism becoming operative when the speed difference between the shaft and motor is increased by the Year running faster to raise the idling speed of the motor, and operating when the overrunning shaft is reduced in speed by the car running slower to decrease the idling speed of the motor.

12. The combination with a motor car of regulating mechanism for the motor fuel supply working in dependency on the speed of the vehicle,

said mechanism becoming operative when the car speed is over a predetermined limit at any time during free-wheeling periods when the motor is declutched to cause the motor to run faster than the minimum idling rate.

13. The combination in a motor car of a clutch, a vehicle power shaft driven by the motor through the clutch, and regulating mechanism for the motor fuel supply working in dependency on the speed of said shaft during periods when the shaft is declutched and overruns the motor, said regulating mechanism operating when the speed difference between the shaft and motor is over a predetermined limit to cause the motor to run at a speed above the minimum motor idling speed, and operating when the speed difference between the shaft and motor is reduced below said predetermined limit to reduce the speed of the motor.

KAIRL MAYBACH.

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