DE1680224A1 - Vehicle braking system - Google Patents

Description

Vehicle braking system

The invention relates to a braking system for motor vehicles and more particularly, a brake control system that prevents the slipping or locking of one or more vehicle wheels prevented as a result of excessive braking.

It is already known that the braking deceleration of vehicles from the frictional engagement of the wheels on the surface depends on which they roll · A maximum braking deceleration is generally achieved when the applied Braking power is just below the value that causes one or more of the wheels to lock or slip. By blocked wheels »those by a excessive brake application are caused,

Sohw / th

set

009885/0746

however, put the vehicle in an uncontrollable state.

When the rear wheels of a vehicle lock, while the front wheels are still rotating at a too heavy braking, the vehicle tries to rotate, and probably results in a harmful Übersteuerungezustand ₉ A locking of the front wheels causes the other side an understeer state, attempts by the vehicle, in continue to move uncontrollably in a substantially straight line when it is assumed that the road surface is substantially flat. Therefore, since rapid and effective deceleration of vehicle speed is generally more important than maintaining full directional control in an emergency, it is desirable that the rear wheels of the vehicle be prevented from locking until the vehicle speed is reduced to near zero or until the front wheels To block. .

When operating a vehicle braking system, the wheel brake assembly shows the tendency to lock on the axle with the lowest axle load before full braking on the other Group of wheel brakes is achieved. This blocking condition is caused by the uneven static load distribution on the vehicle axles and it will nor by the dynamic that occurs during braking

009885/0748

Load shift

Increased load shift towards the front of the vehicle. she The size of the dynamic sound shift is directly proportional to the delay measure.

Usually the static load changes compensated for on the wheels of a vehicle in that Brake cylinders of different sizes can be provided for the front and rear wheels. In a front-engined passenger vehicle or light truck, the front wheel brake cylinders are usually larger than the rear Wheel brake cylinder, so that the load on the front axle greater weight is compensated. However, such differences in the wheel brake cylinder sizes do not compensate for this Dynamic load shift occurring during braking, which results in a reduction in the load acting on the rear wheels

The dangerous condition resulting from a wheel lock becomes even more dangerous when the brakes are applied while cornering. Since locking the front wheels results in an under-inflation condition, the vehicle tries to drive along an arc with an enlarged radius _{in the K 11 Z-Ve.}

009885/0745

The trajectory suddenly decreased so that the rear end of the vehicle tried to turn around the front end. An experienced driver can remedy such a situation by taking countermeasures. In this In this situation, however, there is often an Excessive Correction that causes the rear end of the vehicle to move turns uncontrollably in the opposite direction »

In the case of commercial vehicles, this is a real compensation the braking performance between the front and rear wheels even more complicated · The lack of a correct one Compensation can be provided for commercial vehicles with a uniform structure, such as trucks and buses, as is the case with vehicles with a subdivided structure, such as an articulated lorry and trailer arrangement and tractor and trailer, lead to extremely dangerous situations. Commercial vehicles are often eo designed that the braking ratio between the front wheels and the rear wheels represent a compromise between the loaded and the unloaded state «

By such Komproldi ine except calibrating stability is not secured in the loaded state • while the stability in the unloaded state is considerably reduced. This is the case » because normally

■ ■ ■■ ■ - wisely

009085/0745

wise a considerable shift in weight between one Years without a load and a journey with a load occurs *,

In the unloaded state, the di braking force exerted even during normal braking to lock the rear wheels while the front wheels are still free turning · This condition, which is dangerous with an ordinary truck or bus, becomes even more dangerous when the motor vehicle is pulled out of a tractor that can pull a trailer - whose baths suddenly lock during an emergency brake rod · Because of the greatly increased oversteering property that. resulting from the locking of the rear wheels of the tractor or the baths of the trailer, shows the rear end of the trailer has the tendency to cross the tractor by turning.

This eliminates these dangerous braking conditions becomes a brake control system through the invention created by the oblique inclination of the rear wheels of a motor vehicle during braking is until the front wheels also 'lock · The principles of the invention can also be applied to people driving as well as on trucks, buses, arrangements from tractor units

009885/0748

and tags and the like can be applied. The braking system In short, according to the invention, it consists of means for sensing and comparing the tangential velocity or the speed of the group of front wheels with the Group of the other wheels of the vehicle and of facilities that respond to this comparison in such a way that the braking effect exerted on the rear wheels is reduced when the speed of the rear wheels drops a predetermined value below the speed of the front wheels.

A main object of the invention is therefore to provide a Bremseteuereyetem by which the tendency to lock a Group of wheels of a vehicle before blocking of the other wheels of the vehicle is automatically reduced while the brakes are applied

A specific object of the invention is to provide a braking system in which the application of the brakes the front wheel group of a vehicle is controlled directly by the driver and in which the actuation of the Bremstη the rear wheels of the vehicle on the speed of the front wheels is controlled when the average speed of the rear wheels is lower than that of the Front wheels will.

009885/0745

1680Z24

Another aim of the invention is to provide a brake control

syatem to create that without any significant change of a ready existing brake system in such a * existing braking system can then be installed, the is robust that works independently of the room size, so that different wheel sizes on the vehicle have no effect that can be easily maintained and that in operation

is essentially foolproof. ™

It is also an object of the invention to provide a brake control system to create, at which the operating pressure of the pressure medium for actuating the vehicle brakes on one or more axes rasoh and automatis ch pulsed so that the braking effect exerted on the attached wheels is reduced

An embodiment of the invention is shown like in the drawing. Seig sarin

1 shows an echematic representation of a for a passenger vehicle or the like. certain braking systems » that contains a shape of the invention "

009885/0745

. Fig. 2 shows another embodiment of the invention when applied to a motor vehicle having at least pulls a trailer,

3 is a partially schematic view of an arrangement from a semitrailer tractor and a trailer, in which a slightly modified form of the in Fig.2 the systems shown are included,

4 shows a schematic representation of another embodiment of the invention,

Fig. 5 is a partially schematic view with a

a commercial vehicle provided with a biaxial double rear wheel arrangement, which shows the one shown in FIG the illustrated braking system contains,

FIG. 6 is a circuit diagram of the brake system shown in FIG.

7 is a somewhat schematic front view of a modified form of one used in the invention; all speed sensors acting pick-up unit,.

■ y \ ^ .- ■■, __ . ■ -. Fig . 8 -

* Figure 8 is a cross-sectional view taken along line 8-8 from Fig.7 »

Fig. 9 is a partially schematic sectional view of the Im-i pulse generator from Fig. 1,

Pig · 10 is a schematic view of the in Pig · 2 and in Pig «4 shown pulse generator, and

Pig · 11 a schematic view of a modified scarf « tion, through the air in a pulsating air braking system with a fixed size with pulses is keyed.

In Pig «1 of the drawing there is shown a braking system for a passenger vehicle or a small truck which a combined assembly 10 of a main cylinder and a reservoir for a hydraulic pressure medium

in conventional Permian possesses. The hydraulic cylinder of the arrangement 10 is connected via a line 12 and branch lines 14 and 16 to two brake cylinders 18 and 20 for front wheels 22 and 24 of the not shown driving line; the line 12 is also connected to the input port via line 26 ink pulse generator · 6 $ ztae Irtaat ■ ttutrung connected, which later nooh ftnauer beechritben

009885/0746

will. Si »The exit opening of the pulse generator 64 is through the line 27 is connected to two branch lines 28 and 30. You branch lines 28 and 30 are with two Brake cylinders 32 and 34 for the rear vehicle wheels 36 and 38, respectively. A brake pedal 40 is operative on the arrangement 10 in the usual manner connected.

When the pedal 40 is depressed, this becomes below Pressurized hydraulic medium via line 12 and the branch lines 14 and 16 to the brake cylinders 18 and of the front wheels so that the door brakes 18a and 20a are operated. By depressing the pedal 40, the pressurized hydraulic fluid is overridden the lines 26, 27 »28 and 30 to the brake cylinders 32 and 34 for actuation of the rear wheel brakes 52a and 34a are supplied. Such actuation of the front and rear brakes Bath brakes are quite common and good in technology known"

The wheel brakes 18a, 20a, 32a and 34a apply accordingly the representation in each case a conventional «brake drum 42 and ■ You know beatehtn from some known construction, with apitlswei ·· d · * type ROCIVElL StABDABD STOPMASTEE.

009885 / 07A5

Eb it should be noted that the invention is not limited to a certain type of brake

According to the invention would be the tangential velocity

or the speed of the front wheels 22 and 24 and the

Tangential or rotational speed of the rear wheels 36

and 38 keyed in that each brake drum 42 bits

Notches, discontinuities or teeth 43 is provided - _Λ

and that each one of a series of tones is electromagnetic

Transducers 44, 46, 48 and 50 for each of the wheels 22, 24, 36

and 38 is provided. Each firmly in one place transducers 44, 46, 48 attached to each associated wheel and 50 can each be attached to the support plate of the wheel brakes 80 «,

20a ₁ 32a or 34a be attached «.

The teeth 43 or dl · notches between the teeth 43 and Made of a suitable magnetic material, such as iron, steel, or other material that can be used as a toilet (| Hagnet is attracted · With this construction, the The drum circumference is provided with a number of magnetic elements which are separated from one another or are discontinuous in the circumferential direction τρη. Each of the transducers 44, 46, 48 and 50 has a core which is placed close to the drum circumference containing the teeth 45. When this wheel is rotated, move so the teeth 43 close to their associated transducers Tor-

at 009 * 85/07 * 6.

at, so that the flux density changes in the core areas, will. You therefore speak to transducers 44, 46, 48 and 50 the rotation of the wheels 22, 24, 36 and 38, respectively, so that each has an undulating, substantially sinusoidal electrical Auegangesignal generated whose frequency, pulse width and amplitude of the tangential velocity and therefore the angular velocity of its associated wheel are directly proportional. That for the production of the teeth 43 or the The magnetic material used in between notches does not have to be permanently magnetized as the Converters 44, 46, 48 and 50 can either be provided with a permanent magnet, or by use a polarizing direct current according to the known principle the variable reluctance can be operated

The transducers 44 and 46 are respectively connected to acting as a rectifier detectors 52 and 54 that provide continuous at their outputs two DC voltage levels 22 and 24 are proportional to the D _r ehzahl the front wheels. The output signals of the detectors 52 and 52 are fed to the input of an adder circuit $ 5, from which they are effectively added and fed to a discriminator 56 "

The alternating voltage generated from the transducers 48 and 50

009885/0745

signals are rectified by detectors 58 and 60 in the same manner. The DC voltage levels arising at the outputs of the detectors 58 and 60 are therefore proportional to the tangential speed or the rotational speed of the rear wheels 56 and 38, and they are fed to an adder circuit 61, from which they are added and applied to the discriminator 56 that the output signals of the adder circuits 55 and 61 respectively Ii may correspond to the sum or the average value of D _r ehsahl the front and rear wheel groups of Fahrseugs · *

The polarity of the DC voltage signals fed to the discriminator 56 from the adding devices 55 and 61 is inverted from one another in such a way that the discriminator 56 does not generate an output signal when the input voltage signals have essentially the same value. Accordingly, the discriminator 56 g generates only an output signal when the values are not equal derEingangsspannungssignale. In the exemplary embodiment shown in the drawing, the output voltage signals of the detectors 52 and 54, which correspond to the tangential or angular velocity of the front wheels 22 and 24, are arbitrarily positive, and the initial voltage signals of the detectors 58 and 60, the 4 γ tangential or angular

ices ch windige it 009885/0745

168Q224

speed of the rear wheels 36 and 38 are arbitrarily selected as negative. With this arrangement, the voltage output signal generated by the discriminator 56 is positive when either one or both rear wheels 36 and 38 show a tendency to lock, or start using a lower speed than the gate wheels 22 and 24 to rotate.

The output signal of the discriminator 56 is via a Amplifier 62 is fed to a control relay 210. As will be described in more detail below, the control relay 210 controls the operation of a pulse relay 63, which in turn controls the operation of a pulse generator 64. The control relay 210 is only energized as described below when the output of the discriminator 56 is positive, whereby one blocking one of the Rear wheels or both rear wheels is displayed. Brregen the control relay 210 causes the response Impulse relay * 63, and the response of the Sslais 63 sets the pulse generator 64 in operation. When the pulse generator 64 is in operation, it has a periodic and repetitive effect Interruption of the hydraulic fluid connection between lines 26 and 27. The pressure of the hydraulic brake fluid,

the 009885/0745

which is exerted on the brake cylinders 32 and 34 "is pulsed in this way". By actuating the pulse generator "64 the rear wheel" brakes 32a and 34a are repeatedly released and reinserted so that the rear wheels 36 and 38 try again to assume their normal speed. It is contemplated that it is possible in most Stroabetriehszuständen to omit the control relay 210 from the circuit, W and lay the amplified by the amplifier 62 Ausgangesignal the discriminator 56 for directly to the Impulsrelaie 63, since the task of the control relay is only to To protect the pulse relay 63 from an excessive current flow. This also applies to all circuits described below *

The pulse generator 64 is in operation until the speed sensed by the converters 48 and 50 exceeds the rear μ

wheels 36 and 38 reaches a value that iit weenetlichen equal to the D _r ehzahl the Torderräder 22 and 24 · If this occurs, then the negative value supplied in the discriminator 56 of the detectors 58 and 60 signals is substantially equal to the positive Voltage value of the signals fed to the discriminator from detectors 52 and 52. The output signal of the discriminator

becomes 009885 / 074S

is reduced to zero in this way, so that dae Pulse relay 53 drops out and consequently pulse generator 64 Disables the brake cylinders 32 and 34 to operate the wheel brakes 32a and 34a in the normal manner can operate

Details of the circuit described so far are further described below.

In Fig. 2 a modified braking system for a typical combination of a tractor and a trailer is shown. So much for the braking systems of Pig.1 and Pig.2 are the same, to identify the same parts as "tracing" have been used as in Pig · 2 and ^ ig.3 is shown, the wheels 22 and 24 are the front wheels of the tractor, the wheels 36 and 38 are the rear wheels of the tractor and the wheels 96 and 98 are the rear wheels of the trailer.

In the brake system of Figure 2, the supply of compressed air is controlled by a shut-off device 10a, which is controlled by a Pedal 40a is operated. An air reservoir 68 attached to the tractor is connected via a line 66 to the The inlet opening of the shut-off element 10a is connected to the outlet opening of a pump 70 through a line 72 to the

Air- 009885/0745

Air reservoir 68 viewed. A check valve built into line 72 blocks one Return flow from the air reservoir 66 to the pump 70 The pump 70 driven by the tractor engine, not shown, fills the air reservoir 68 old Compressed air The pump 70 also supplies compressed air via a line 78 to one attached to the trailer

m Luftvorratsbehajter 76. An applied in line 78 W

Check valve 80 introduced blocks backscattering from air reservoir 76.

When the pedal 40a is depressed, compressed air is supplied to the branch lines 14 and 16 via the line 12 from the shut-off element 10a, so that the front brake cylinders 18 and 20 are actuated in the usual manner. Via the line 27 is also the serving of the brake control pulse 64a compressed air supply μ

out and for actuating the brake cylinder 32 and the rear wheels will take the branch lines 28 and 30 over the line 27 is supplied with compressed air · The construction of the pulse generator 64a is described in more detail below »

The compressed air supplied through the shut-off device 10a

is also via a line 82 and a protective cap organ 83 for the tractor, so that a relay

and 009885/0745

and valve 84 is moved from a normally closed condition to an open condition. The outlet opening of the relay and excrement shut-off device 64 is via a line 86 with. the entrance opening of a other pulse generator 114 connected to brake control. The outlet opening of the pulse generator 114 is connected by a line 87 to two branch lines 88 and 90, which in turn with the brake cylinders 9t and 94 of Trailer wheels 96 and 98 are in communication. The brake cylinders 92 and 94 form parts of the bath brakes 96a and 96a, respectively. 98a. When the relay and emergency shut-off device 84 is open, is therefore used to operate the wheel brakes 96a and 98a Compressed air supplied.

In the embodiment of Pig.2, the pulse generator 64a has a three-way shut-off element actuated by an electromagnet, which can be actuated in such a way that em controls the compressed air supplied to the brake cylinders 32 and 34. If the sum of the speeds or tangential speeds of the rear wheels 36 and 38 of the tractor during the braking operation is less than the sum of the speeds of the door wheels 22 and 24, then the pulse generator 64a is actuated so that the flow connection between the lines 26 and 27 is interrupted

will

009885/0745

and that the conduit is opened to the ambient air is, whereby the exerted on the wheel brakes 32a and 34a Braking force is reduced until the rear wheels 36 and 38 assume speeds, the sum of which is essentially is equal to the sum of the speeds of the front wheels

In Pig, 2 there are additional rectifying detectors 51 and 53 for the front wheels 22 and 24 respectively (§

· The output of transducer 44 is electrically connected to the input channels of detectors 51 and 52. The output of the transducer 46 is electrically connected to the input channels of the detectors 53 and 54. The detectors 51 and 53 therefore have the same output signals as the detectors 52 biw « 54» Wit was already mentioned above, the output channels of the detectors 52 and 54 are electrically connected to an adder circuit.The output channels of the detectors 51 and 53 are connected to a further adder circuit 103 in connection·

The trailers 96 and 98 are also provided with transducers 104 and 106 sun buttons for the speed, and the transducers are electrically connected to the input channels of the rectifying detectors 107 and 108, respectively. The output channels of detectors 107 and 108

sini 009885/0745

are electrically connected to the input channel of an adder circuit 110, the output of which in turn is connected to a comparative discriminator 102 is electrically connected · The adding circuits 103 and 110 can the same circuits as the adding circuits 55 and 61, and the discriminator 102 may be the same Be a discriminator like the discriminator 56 · Likewise, the detectors 107 and 108 can be such detectors as the detectors 58 and 60 «

In the same way as the wheel brakes on the tractors nen also the wheel brakes 96a and 98a of the trailer each be provided with a brake drum 100, the Teeth 101. The teeth 101 or those in between lying notches are made of magnetic material * The transducers 104 and 106 are constructed exactly as the converters for the baths of the tractor. The. Converter and 106 therefore generate wavy, essentially sinusoidal electrical output signals, the frequencies of which Pulse widths and amplitudes are directly proportional to the tangential speeds or axes of rotation of the loaders 96 and 98, respectively.

The output voltage signal of the adder circuit 110 1st

". ■ - ■■ '- ,; ■■ -. Negative ^:

ÄS88S / 0745

is made negative, and it is supplied to the discriminator 102 to be compared with the positive voltage signal supplied from the adder circuit 103 will «When wheels 96 and 98 of the trailer begin, To rotate slower than the wheels 22 and 24, then the value of the negative voltage signal supplied from the adder circuit 110 is less than the value the positive one supplied from the adder circuit 103 Voltage signal · The output signal of the discriminatorβ 102 therefore becomes positive, as has already been described in the embodiment of FIG.

The output signal of the discriminator 102 is applied via an amplifier 111 to a relay fi2, which is essentially a relay like the control relay 110. Therefore, when the difference between the summed rotational speeds of the wheels 96 and 96 dee trailer and the summing exceeds 22 and 24 a "predetermined size a ten speeds of the wheels, then the ROM discriminator sufficient generated Auegangssignal because · relay 112 energize shown below. When the relay 112 responds, an electromagnet 404a is energized which, on the one hand, puts the pulse generator 114 into operation in such a way that it releases the air pressure indicated by 92 and 94 in the br eaesyl. The braking effect exerted on the trailer wheels therefore also allows naoh,

bie

009885/0745

until the trailer wheels reach a speed again » which is equal to the speed of the front wheels 22 and 24.

Aue of the above description it can be seen that the embodiment of ^Ji ig.2 for the operation of a in Pig. 3 can be used in which a tractor 116 pulls a single-axle trailer 118 with the aid of a fifth-wheel coupling 120, a trailer 122 with four wheels being pulled, for example, by being attached to the single-axle trailer 118. The trailer 122 has a front axle 130 and a rear axle 132, wheels 23 and 25 are attached to the front axle 130, and wheels 99 and 99 are attached to the rear axle 132. The wheels 22 and 24 are attached to the front axle 124 of the tractor 116, and the wheels 36 and 38 are yelled at the rear axle 126 of the tractor 116. In addition, the wheels 96 and 98 are attached to a rear axle 128 of the single-axle trailer 118.

Se can be seen that the example τοη Pig.2 is also like this that can be added to the turning grinders of the wheels and 24 of the front axle 124 corresponding electrical Signals to control the application of air pressure the braking devices of wheels 23, 25, 97 and 99 in addition to wheels 96 and 98 of the trailer and

the 009885/0745

the wheels 36 and 38 of the tractor can be used. In this way, wheels 23, 25, 97 and 99 become, in addition to wheels 36 and 38, of the tractor and the wheels 96 and 98 of the trailer are prevented from locking during the application of the brakes, as long as the front wheels 22 and 24 of the tractor 116 can rotate freely.

A modified braking system is shown schematically in FIG which is similar in some respects to the Pig.2 braking system. So much for the braking system of Fig. 4 is the same as the braking system described above, the same reference numbers have been used to identify the same parts.

As can be seen from Fig. 4, those of the adding attitude 61 supplied output signals of the detectors 56, 60 107 and 108 are optionally selected to have negative polarity. That from the adder circuit generated resulting output signal which the discriminator 56 for comparison with that from the adder circuit 55 supplied positive signal is also negative «The generated by the adder 55 · positive signal is proportional to the sum of the speeds of the front wheels 22 and 24, as already mentioned above

became. With this arrangement, the pulse generator 64a therefore put into operation when the speed is at least one of the rear wheels 36 »38, 96 and 98 is reduced in relation to each other, so that there is a suitable position between the positive and negative adding values determined by the discriminator be compared, an · inequality with predetermined Size occurs.

In the embodiment of Pig. 4, all brake cylinders 32, 34, 92 and 94 are connected to the outlet opening of the pulse generator 64a. The activity of the pulse generator 64a therefore interrupts the flow connection between the Shut-off device 10a and the brake cylinders 32, 34t 92 and 94, and it relaxes the compressed air so that the bath brakes 32a, 34a, 96a and 98a can be loosened evenly. As has already been described above, the pulse generator 64a activated by the energization of the control relay 210, which in turn is energized when the discriminator 56 has an output signal of a predetermined magnitude generated that is a predetermined difference between the compared positive and negative output signals corresponds to the adding circuit.

Since · BremeiyeteM from? If.4 can be beneficial for the in

The vehicle shown in FIG. 5 can be used at the baths 22 and 24 as described above on the front axle 124 and wheels 36 and 38 and baths 96 and 93 are attached to rear axles 128 and 129, respectively.

In Fig.6 the details of the circuit of # ig.1 shown. The transducer 44 consists of a permanent magnet core 140 »which has pole pieces 142, which is close to the teeth 43 of the brake drum d ·· wheel lie. By rotating the wheel 22, the flux density in the permanent magnet core 140 is changed in such a way that that in a pick-up coil 144 an alternating voltage signal is induced. At the end of the pick-up spool is connected via a capacitor 146 to the rectifier circuit of the detector 52, which is a · in

Series to the capacitor 146 lying diode 148 and another diode 150 contains. Diode 150 is between the output terminal of capacitor 146 and an electrical connection line 152 · The ends the pick-up coil 144 are connected to the connection line 152 or to the input terminal of the capacitor 146. A capacitor 154 forming part of the The rectifier circuit is located between the cathode, the diode 148 and the connecting line 152 · D «r Resistance 156 of a potentiometer 158 that controls the Au -

009885/0746

The output for the rectifier circuit is connected in parallel with the capacitor 154. One at the AC voltage caused by pick-up coil 144 the occurrence of a corresponding DC voltage. the booths of the resistance 156, as in technology is well known.

You little 159 of the potentiometer 158 is at all times positive against terminal 160 and that through the resistor 156 flowing current depends on the time constant of the BC-GIi ed es, which is formed by the resistor 156 and the capacitor 154. This time constant is used by the time it takes to discharge this capacitor via the potentiometer. When the frequency of the alternating current generated by the pickup coil 144 increases, then the peak value of the voltage between terminal 159 and terminal 160 of the potentiometer

meters so that the grinder 164 of the Potentiometer 158 tapped positive DC voltage as a function of the. The speed of the front wheel 22 changes.

The circuit of transducer 46 and detector 54 is executed exactly as the circuit that just for transducer 44 and detector 52 has been described. Accordingly, they are also the same for labeling

009885/0746

Parts like designations have been used, except that the reference characters for the transducer 46 and the detector 54 have been provided with the letters ⁿ a *.

The transducer 46 and the detector 54 work exactly as they do for the transducer 44 and the detector 52 * So an alternating current signal induced in the pickup coil 144a generates a positive direct voltage signal at the terminals of the potentiometer 158a.

The dike voltages applied to potentiometers 156 and 158a, which are suitable for the turning axes of the gate wheels 22 bsw “24 correspond” to the grinders 164 and 164a sucked. The wiper 164 and 164a are through the resistors 170 BSW. 172 "connected to a conductor 168. Conductor 168 connects the respective ends of resistors 170 and 172 to one end of a temperature sensitive resistor or thermistor 174, the with its other brew connected to a voltage-setting resistor 175. The resistor 175 forms sueamnen the circuit of the discriminator 56 with a grinder 206. The addition 55 is controlled by a Resistor 173 together with resistors 170 and 172 ! • that are connected to one another in such a way that the

BATH ORIGINAL

Output signal of the adding circuit with the sum of the is related to two input signals

With certain exceptions to be described, the circuits of transducers 48 and 50 and actuators 58 and 60 are the same circuits as were just described for transducers 44 and 46 and detectors 52 and 54. Accordingly, the same reference numerals with the letters "b" have been used to identify the components of the transducer 48 and the detector 58, while the same reference numerals are ^{provided with the letter M} c "to identify the components of the converter 50 and the detector 60 Reference numerals have been used.

These circuits associated with rear wheels 36 and 38 are the same circuits as the circuits associated with front wheels 22 and 24 except that the connection to the anodes and cathodes of diodes 150b, 150c, 148b and 148c are reversed. The terminals 160b and 160c and the corresponding ends of the pickup coils 14: 4b and 144c, the diodes 150b and 150c and the capacitors 154b and 154c are all connected via a common connection line 186 to a reference potential source such as Hasse 187, ie connection line 152 009885/0745

device 152 also connects terminals 160 and 160a, the corresponding ends of the diodes 150 and 150a, the pickup coils 144 and 144a and the capacitors 154 and 154a with the same reference potential. Through this Therefore, the voltages applied to potentiometers 158b and 158c are negative and with respect to the circuit the voltages on potentiometers 158 and 158a are opposite polarized.

According to Pig, 6 the grinders 164b and 164c are about the Resistors 202 and 204, respectively, are connected to end 175a of resistor 175. The other end 175b of the resistor 175 is as described above connected to the respective ends of resistors 170 and 172 through resistor 174.

The rectified, negative voltage signals, which correspond to the speeds of the baths 36 or «» 38, are transmitted through the resistors 204 and 202 and also passed through the resistor 203. The ends of resistors 202 and 204 connected to end 175a are through the resistor 203 is connected to the connecting line 186. The resistances 202, 203 and 204 form 00 the adding circuit

tion

Q098B5 / 0746

'! 680224

'.' - 30 device 61, which acts in the same way as the adding circuit 55.

The wipers 164, 164a, 164b and 164c are optionally adjustable so that a symmetrically balanced voltage difference is provided at the resistor 155 before operation. After setting the wiper 164, 164a, 164b and 164c, the wiper 208, which forms a sliding contact on the resistor 175, is brought into a position in which the voltage signal occurring across it is equal to zero when the absolute values of the two at the ends 175a and 175b applied opposite voltage signals are the same.

In this way, the voltage signal appearing at the wiper 208 is always zero when the voltage signals applied to the wipers 164 and 164a have the same value but the opposite sign as the sum of the voltage signals appearing at the wipers 164b and 164c. This condition occurs when the rear wheels 36 and 38 have the same tangential speed or rotational speed as the front wheels 22 and 24. However, as soon as one or both of the rear wheels 36 and 38 are rotating more slowly without a corresponding slowdown in the speed of one or both of the front wheels 22 and 24, the amount of the

at 009885/0745

- 51 -

positive voltage signals applied to end 175b are correspondingly greater than the magnitude of the voltage applied to end 175a. Consequently, a positive voltage signal is applied to wiper 206 and fed to amplifier 62 where it is amplified and sent through a branch line having a forward diode 209 and the working winding 211 of the control relay 210 · The winding 211 which Diode 209, amplifier 62 and wiper 280 are connected in series between resistor 175 and the connecting line.

The diode 209 prevents the relay 210 from being energized when a negative voltage is applied to the wiper 206. This condition occurs when the front wheels 22 and 24 lock while the rear wheels 36 and 38 are still rotating. However, a positive voltage signal occurring at the wiper 208 is fed to the winding via the diode 209.

When the difference between the at ends 175a and 175b occurring tensions increases because one of the rear wheels or both rear wheels 36 and 38 with less Rotate speed, takes the positive voltage on Grinder 208 until it reaches a value that is one

for 00 98 85/0745

• sufficient current flow through the winding 211 for the operation of the control relay 210 causes this excitation of the relay 210 causes an excitation of the pulse relay 63 »which in turn causes the pulse generator 64 in the manner described above puts into operation «By the Activity of the pulse generator 64 is the pressure of the pressure medium exerted on the brake cylinders 32 and 34 Pulses are keyed, so that those on Hader 36 and 38 effective braking power is reduced

The thermistor connected in series with resistor 175 1? 4 causes an increase in the speed difference required to trigger the pulse generator 64 when the Vehicle speed increases, making the pulse generator less sensitive to small fluctuations between wheel speeds during routine high-speed braking. this will explained in more detail below

The electrical line required for the operation of the pulse relay 63 and the pulse generator * 64 is provided by a Battery 214 supplied. Is parallel to the winding 211 a Zener diode 216, through which the winding is protected from being conductive when the

the

009885/0745

voltage lying around the winding is large enough to generate a Cause destruction au · This limits the way Zener diode 216 reduces the voltage across winding 211 to a safety value. The control relay 210 has a contact 212 which is closed when the winding 211 is energized. Parallel to Eontakt 212 lies a diode 215, which opens the switching contact before Protects against excessive arcing · As can be seen in the diagram, the circuit is also a limiting resistor 217 built in, so that the Zener diode 216 is protected from a dangerous current flow

In ^f ig.7 and in Pig.8 an electromagnetic transducer 219 is shown, which can be vorwendet instead of the above-described converter · The transducer 219 has a group consisting of a permanent magnetic core 220 'of the generation of Polfläohen 222 and 224. U-shaped This core is preferably made of a strongly magnetic material such as Alnioo. A coil 226 is wound around the core 220 as shown. The transducer 219 can be mounted in a tubular housing 232, which is preferably made of a suitable magnetic sealing material is made All cavities of the arrangement,

like 009885/0745

as shown at 234, can be filled with a vitreous casting material, epoxy resin or the like. Bas pouring material also acts as a Solidifying agent through which the individual parts of the. Converter 219 are held firmly in place.

When transducer 219 is used in place of transducers 24 »46, 48 and 50, the movement of teeth 43 past the area of core 220 creates a series of voltage pulses in coil 226. The frequency, the amplitude and the pulse width of these pulses are then proportional to the tangential velocity or the rotational speed of the associated bath. These pulses are then applied to the discriminator via the associated detector in the manner described above.

In Pig. 9 the pulse generator 64 is shown as having a housing 300 to which an electric motor 302 is attached. The electric motor 302 has an ^A uagangswelle 304 on which a worm wheel is attached 306th The worm wheel 306 continuously meshes with a gear 308 which is splined on a shaft 310. An eccentric cam 312 is attached to the shaft 310 and has an extension which normally acts on a plate 314 . 009885/0745

The plate 3H is attached to the end of a piston 316, which extends slidably into a bore 318 « The bore 318 is in turn made in the housing 300 A coil spring 320 located between the plate 314 and a shoulder 322 mounted in an inner housing recess 324 presses the plate 314 and the

Piston 316 up. The lower end of the piston 316

M can releasably ww onto the upper end of a rod 326

works. The rod 326 and the piston 316 are axial in the same direction in hole 318 »

A conical valve member 328 is attached to the lower end of the rod 326. An annular wall 330 at the lower end of the bore 518 forms a frustoconical seat 332 against which the valve member 328 can fit tightly so that the flow communication between the cameras 334 and 336 is interrupted · is ^{ΰ ίβ} chamber 536 μ is in the lower end of the housing 300 and communicates via an opening 338 with the conduit 26 in connection. The chamber 34 is delimited at the lower end of the bore 318 and is in communication with the line 27 via an opening 340. By actuating the valve part 528, the pressure medium connection between the lines 26 and 27 is controlled.

'SäSfe

009885 / Q745 ■. ■

According to Pig. 9, a helical spring 344 is also attached in the chamber 336, which spring against a plug 350
acts so that a holding plate 342 is pushed upward. On the ^u old plate 342, a valve member 328 is attached. The biasing force exerted on the helical spring 344 thus presses the valve part 328 upwards against its closed position. The retaining plate 342 is attached to a piston 360 which slidably extends into a guide bushing 348.

Radial openings 352 made in the guide bushing 348 are attached, are in communication with the longitudinal bore that receives the piston 346. With this construction, an accumulation of brake fluid is under the lower end of the piston prevented.

The guide bushing 348 is fixed to the plug 350
connected, which is screwed into the housing 300 as a closure of the chamber 336. As can be seen from the illustration, the helical spring 344 defines the guide bushing 348.

An electromagnet is attached to one side of the housing 300 and is provided with a coil 356 which receives one end of a piston 358. The other end of the piston 358, which extends into the housing 300,

besltst
00 9885/0745

- 57 -

has a fork-shaped end 360. With this fork-shaped end 360, a pawl part 364 is through a Pin 362 rotatably connected

This is on a pin 366 attached to the housing 3Q0 Pawl part 364 rotatably mounted · By an axial Displacement of the piston 358 becomes the pawl member 364

pivoted about the axis of the pin 366. On the ~

Pin 366 opposite end of the pawl member 364 has two stepped edges 368 and 370 attached. '.

As can be seen from Figure 9, the edge 368 of a Coil spring 363 in single grip with the side of the plate

pressed. You coil spring 363 that drives the piston 358 surrounds, presses against a holding plate 365, so that the

Piston 358 is pushed to the right in the illustration, M

whereby the pawl member 364 is again shown counter-clockwise about the axis of the pin · 366 is pressed · When the coil · 356 is energized, the

Piston 358 shifted to the left so that the pawl part

364 in the opposite direction to that of the

Spring 363 exerted bias is pivoted.

That

009885/0745

The latch part 364 let according to the coffin position provided with an abutment 372 extending from the edge 368, which is moved by the helical spring 363 into a position is pressed in which it latches over the plate 3H. If the excitation of the coil 356 is interrupted, the starting from the position of FIG. near upward displacement of the plate 3H by prevents engagement with the downwardly directed edge of abutment 372. In this position of the pawl part 374, the edge 370 is held by the helical spring 363 brought into engagement with a spring leaf 374 held in a cantilevered manner.

The leather sheet 374 carries a contact portion 376 which is moved away from the contact position with a fixed contact portion 378 when the edge 370 engages the free end of the? _e derblattes 374. is brought. The contact part 378 is on a rigid »/! Support 380 attached, which in turn is attached to the housing 300. Thus, when the coil 356 is not energized, the contact parts 376 and 378 are kept open. If, on the other hand, the coil 356 is energized, the piston 358 is displaced to the left, so that the pawl part 364 is also displaced to the left, whereby the plate 314 is free to perform an upward movement.

given 009885/0745

is given, and thereby the contact of the contact part 376 with the contact part 378 is enabled.

When the control relay 210 all the sequence of one through the Winding 211 flowing current of predetermined magnitude is excited, then the contact 212 is closed with it a circuit is closed that prevents the flow of the current from battery 214 for excitation the winding 384 of the pulse relay 63 allows. By the excitation of the pulse relay 63 becomes a two-pole Switch 386 closed, which in turn turned on The circuit leading to the excitation of the motor 302 is closed via the terminal 388 and a line 394 Closing the switch 386 simultaneously closes one via a second terminal 390 Excitation of the coil 356 leading circuit. By the excitation of the electric motor 302 is rotated the cam 312 so that it is down on the Plate 314 pushes, which then jointly with the piston is pressed straight down against the biasing force exerted by the coil spring 320. Through this the pawl member 364 is released from any load and the spring 363 is compressed when the plunger 358 is moved to the left by the energization of the coil 356 is moved. The pawl member 364 thus leads a

Tilt 009885/0745

, kung to the left without being disturbed by the occurs from the cam to the motion transmitted by the plate 314.

By loosening the pawl parts 364 you can calibrate the Touching contact parts 376 and 378 »By touching the contact parts 376 and 378, a Haiteetromkreie is created provided for the electric motor 302. As below As will be described in more detail, the purpose of this holding circuit is to control the sequence in which the excitation The electromagnet 354 and the electric motor 302 are interrupted is, so that it is ensured that the ropes of the pulse generator 364 back into the one shown in * 'ig.9 Return to standby.

The rotation of the cam 312 gives the plate 314, piston 316 and valve member 328 in cooperation with the coil spring 320 an up and down movement. With each rotation of the cam 312, the valve part 328 is closed and opened.

The reciprocation of the piston 316 and the bore 318 causes the displacement of the piston to increase and decrease in accordance with the sighting of the piston Volume of the Kamaer 334. As soon as the valve part 328

SSL 009885/0745

rests on the seat 352, so that the pressure medium connection

interrupted between chambers 536 and 334, becomes the pressure in chamber 334 because of the continued upward displacement of the piston scaled down. Consequently, the pressure exerted on the brake cylinders 32 and 34 of the rear wheels by the pressure medium is therefore Reduced pressure. The next downward movement of piston 316 - the pressure will the pressure medium in the chamber 334 is then increased until the full pressure is again exerted on the brake cylinder becomes, when the valve part 328 opens, so that a complete again between the -K-chamber 336 and the chamber 334 Pressure medium connection is established. In this way, the pressure of the pressure medium in the line 27 pulsed so that the effective braking torque exerted on the rear wheels is reduced. Through this the speed of the rear wheels can increase again until the sum of their speeds is equal to the sum again the speed of the front wheels. When this condition occurs, the voltage signal on the grinder drops 208 to * zero, so that the control relay 210 below open of contact 212 drops. By opening the contact 212 also drops the relay 63, so that the switch is opened. By opening switch 386, the excitation of the coil 356 interrupted so that the

Coil spring 009885/0745

Helical spring 363 can bias the pawl part 364 again in its δ in ^ ¹ Ig ₀ 9 shown engagement position

Because of the holding circuit provided by the contact parts 346 and 378, the electric motor 302 remains energized even after the switch 368 is opened. This is performed so that the pulse generator 64 safe always in i ^l ig _# occupies the standby position illustrated 9, thus the same for the operating position in the next braking period without Eücksicht to the relative the plate 3H to the pawl member 364 at the moment of interruption of the excitation of the electromagnet 354 is set correctly. If the plate 314 is pressed sufficiently far down at the moment of the interruption of the excitation of the electromagnet 354 by the cam 312, the pawl member 364 moves under the pretension exerted by the coil spring 363 to the right, so that it pivots into its standby position shown in which there is no interference with the leftmost vertical surface 375 of the plate 3H. When the latch member 364 pivots to the right, the edge 370 acts on the Eederblatt 374 a, so that the contact portions 376 and 378 separated from each other and the old interrupt ^a circuit of the electric motor 302nd The plate 314 moves

then 00 9885/07 4 5

then under the influence of the coil spring 320 exerted preload and the further rotational movement of the motor taking place due to inertia upwards, to it assumes the standby position shown. The electric motor 302 can be in any position stop. When the latching movement of the pawl part B. on the other hand, occurs at a point in time when the plate 314 is at the top or near the dee is located at the upper end of its stroke movement, then the abutment 372 abuts the surface 375, so that the movement of the pawl part 364 to the right is limited. However, this limited movement of the pawl part 364 is not sufficient to separate the contact parts 376 and 378 the end. The electric motor 302 therefore remains switched on until the plate 3H is removed from the cam 312 has been shifted downward by a sufficient distance so that the pawl part 364 can move to the right as far as the position shown in FIG. 9 continues During this continued movement, the edge 370 acts on the end of the pedal blade 374, so that the contact parts 376 and 378 are separated with the interruption of the excitation of the electric motor 302 · The Plate 3H is now because of the door tension force exerted by coil spring 320 and that of the rotational movement of the electric motor caused by inertia

- gates

009885/0745

■ -168Q224.

* 44 -.

tors 302 after a shutdown in their shown Standby ·

From the above description it can be seen that the pulse frequency, which is preferably about 5 - 6 Hz, a function that is the speed of the electric motor 302.

The thermistor 174 shown in Fig. 6 is a resistor having a positive temperature coefficient. That means that it is a resistance, its electrical Resistance increases with its temperature. When the speed of the vehicle increases and the tension the alternating voltage signals generated by the transducers 44 and 46 attached to the door wheels increases, it can be seen that the thermistor The rectified current flowing in 174 causes an increase in the temperature of the thermistor 174 The resulting increase in resistance becomes the positive voltage applied to resistor 175 on it Way reduced.

Accordingly, a negative voltage signal is required to compensate for the positive DC voltage signal, which is an indication of the speed of the front wheels

the 009885/0745

corresponds to the speed of the rear wheels of the vehicle. This has the consequence that a sufficient current flow through the diode 209 and the winding 211 of the control relay 210 occurs so that the contact is closed only when the difference occurring between the speed of the front wheels and the speed of the rear wheels is greater than that Case is as if the temperature-dependent thermistor 174 would not be built into the circuit. Ba can be seen in such a way that the sensitivity of the circuit with the Vehicle speed decreases a little, so that at high. Speeds a certain tendency of the rear wheels to lock before the pulse generator starts working while the pulse generator starts working at a low speed as soon as the speed of the rear wheels during braking is only a small amount below the speed of the

Front wheels sink. The use of the above-mentioned device is optional

It is obvious that the temperature-dependent thermistor 174 is not essential and can be omitted if desired. ^ benso it is obvious that a resistor with a negative temperature coefficient to further reduce the sensitivity of the systems at high speeds in line 206 swieohtn

to the 009885/0745

the resistance 175 and the common connection point of resistors 202, 203 and 204 could be turned on. The same effect can also be achieved by using a differential amplifier with one input is connected to the output of the discriminator, and the other input is connected in this way is that it picks up a fraction of the output signal of the adding circuit of the front wheels.

The pulse generator shown in Fig. 9 can be particularly can be applied well to a static hydraulic braking system such as is commonly used in passenger vehicles and ,, small truck is used. Such a conventional system is shown schematically in Fig. 3 * Because of the variable, pulsating volume of the chamber 334, the pulse generator 64 scans the brake cylinder 32 and 34 applied hydraulic pressure, thereby pulsating, that a predetermined amount of fluid is alternately separated from the brake cylinders 32 and 34 in a closed hydraulic circuit and reapplied to it. ·

is also evident that at a desirable Increase the amount of brake control in each connection line to the inlet ports

008S8S / 074S

BAD ORIGINAL d he «

τ *

which one pulse generator can be switched on · associated discriminators and control arrangements allow «that during the braking action pulse-shaped pressure exerted on each brake cylinder is scanned as soon as each wheel on one of the rear axles of a motor vehicle or on the axle of a τοη one Tractor-towed trailer in relation to the speed of the wheel groups on the front axle is caused in To run more slowly in relation to the speed of the wheel groups attached to the front axle,

It should be noted that the adding action of the adding circuits (i.e., the adding circuits 55 and 61 of Fig and Pig. A and the adding circuits 55, 61, 103 and 110 of FIG. 2) have the purpose of eliminating the speed differences of the wheels that normally occur when cornering. As can be seen, each of the above-mentioned adding circuits causes the input signals to be numerically added and the sum divided by a constant · so that the output signal of an adder circuit corresponds to the sum of the input signals the wheels 24 and 38 both rotate at corresponding speeds which are correspondingly lower than the speeds of the wheels 22 and 36. The fact of the slower rotation of the wheel 38 continues

the 00988S / Q745 ■ '·

the pulse generator 64 is not in operation because the sum of the from the adder 55 added Voräerradepension signals equal and with respect to the sum of the from the Adding circuit 61 added rear wheel voltage signals is polarized opposite.

It can also be seen that two or more encoder pistons are pulsed by a single motor when used in a dual circuit braking system will know. -

With the air brake systems shown in Pig. 8 and 4 For example, the pulse generators 64a and 114 can be any commercially available pulse generator consisting of electromagnetically actuated, .spring_loaded three-way air shut-off devices such as the shut-off element 400, which is shown in FIG is shown schematically. Bas shut-off device .400 is a normally open three-way shut-off valve, as ee one Internal lead-through 402, which normally provides a pressure medium connection between lines 26 and 27 provides · If one of the pedals 40a of Pig · 2 or Pig «4 to produce a pressure medium connection between the air reservoir and the line 26 depressed compressed air therefore flows through the bushing into line 27, so that the wheel brake cylinders of the rear

009885/0745

wheels are operated. When the average tangential speed or speed of a group of wheels behind the front axle below the average Speed value of the front wheels decreases, however, the control relay 210 in the above-described Wise excited so that contact 212 is closed « Closing contact 212 also creates a circuit closed to excite an electromagnet 404. The electromagnet 404 is connected to the movable actuating element of the shut-off element 400. When the electromagnet 404 is excited, it moves the shut-off element 400 into a position in which the line 27 is separated from the line 26 and is connected to an outlet port 406.

The compressed air present in line 27 can therefore relax, and the rear wheel brakes are released so that their average Dreheahlwert in an effective manner again assumes the Duroh section speed of the front wheels, so that the control relay 210 opens the contact 212Γ and interrupts the excitation of the% ektromagnets 404 drops, so that the compressed air can again flow freely via the feed-through 402 from the line 26 to the line 27. If this second application of air pressure to the brake cylinder is still too great for the existing conditions and if again an over-

009885/0745

large deceleration of one or more of the rear wheels 36 and 38 occurs, then the electromagnet is re-energized, as a result of which the air applied to the brakes can flow out through the opening 406 into the environment, as has already been described above. This pulsation process continues automatically as long as the brake pedal 40a remains depressed and as long as the excessive W deceleration of one of the rear wheel groups continues to occur at a given pressure applied to the brake actuators.

From the above description it can be clearly seen that by the invention a braking system is provided in which the rotation of the wheels on any axis with the Rotation of the wheels on any other axis can be compared so that the control of the pressure of the Pressure means of the brake cylinders of the decelerated wheels _ when the wheels on one axle are rotating at a lower speed than the wheels on the other axle try to turn while braking, impulsively is keyed until its speed is back to the The speed of the axis acting as a reference force is increased Has.

The comparison of the hydraulic braking system

from

009885/0745

From Pig «1 according to the invention with the air pulley brake systems of Fig. 2 and Pig.4 it can be seen that the hydraulic system is pulsed with a fixed size, that is with a certain number of periods per second, when the discriminator 56 has an output signal generated, the size of which is sufficient to operate the control relay 212. However, the air brake system does not sense the pressure of the pressure medium in a pulsed manner, Λ

when the rear wheels are controlled by the front wheel group. You leave it on the rear brake cylinder Applying compressed air to the air brake system instead its outflow, and no new pressure is applied until the rear wheel speed has been brought up to the speed of the front wheels, at full air pressure is now placed on the rear brake cylinder again However, if so desired, the air brake system can also operate in a predetermined manner

■ ■ ■ ■ - ■ ■ ■ i

Wet ait impulses are keyed «The simple block ~

circuit diagram, from fig * 11- indicates how the one in Pig.2 and Fig.4 systems shown to achieve this result can be changed

Assuming that the discriminator 56 produces a positive output signal in the usual manner, the control relay 210 is energized, which is a signal

erzemt 009 885/0745

generates »because a blocking oscillator 406 is triggered. So long the control relay 210 remains energized, the blocking oscillator 406 generates «in« series τοη pulses with a fixed » preferably at a value of 3 - 5 Ha. This pulse frequency is a little lower than the corresponding frequency of the hydraulic pulse generator (5-6 Hs), because there are mechanical limitations in the system when air is released the pulse generator '64a are set at a higher frequency.

The output signal of the blocking oscillator is fed to a monostable multivibrator 408, generally referred to as a flip-flop, which is used to excite a square wave from the blocking oscillator pulses then effected by the application and removal of the air pressure to the rear brake cylinder "that the air flowing in the pulse generator 64a air is regulated in the hang above in conjunction with Figure 10 described · V _e · ise

individual components of the automatic pulse generator described above are well known in the art.

Claims t 009885/0745

Claims (1)

Claims 1) vehicle brake system with optionally applicable, Pressure-operated front and rear breasts for a smaller vehicle wheel group acting on the floor and at least one rear wheel group acting on the floor, characterized by devices responding to a certain speed difference between the bath groups to reduce the effectiveness of the brakes, so that the rotation of one of the wheel groups is delayed when the brakes are operated selectively 2) ^ ahrzeugbremseystem according to claim 1, characterized in that one of the bath groups is the rear is located in the bathroom group, and because of the facilities only the effectiveness of the one in the rear is effective Braking is only to be reduced if the speed of the rear bath group is less than the speed of the bath group lying on the rom is 5) Vehicle brake system naoh claim 1, characterized in that the devices load a device 009885/0745 sitsen, old who the pressure of the pressure medium, who sur actuating the brakes of one of the Sadgrupptn is applied, regardless of the pressure of the pressure medium, the sur actuation of the other bath groups ▼ is used, bit pulses are repeatedly keyed 4) _{Fahrzeugbremssyttem according to spoke I 9} characterized by the fact that the devices have a gate direction through which the pressure of the pressure medium, which is used to actuate the brakes of one of the bath groups, independently of the pressure of the pressure medium, which is used to actuate the brakes of the other Bath groups is applied »yellow is · 5) lahrseugbremssystem according to claim 2, characterized by further brakes for a »further group τοη arranged at the rear, acting on the ground and by further devices, through which the effectiveness of the further brakes when a doorway difference occurs between the TOTümn and the other pool group is to be reduced, so that the twisting of the associated bath group is generated independently τ · η of the effectiveness of the rear brakes, so that the rotation too 009885/0745 - 55 - whose associated bathroom group is delayed 6) Vehicle brake system according to claim 3t, characterized in that the pressure of the pressure medium with one fixed, predetermined amount is scanned with pulses " 7) Fahrzeugbreaasystem according to claim 6, characterized in that a hydraulic fluid ^ uelle pressure of the Provides pressure medium for actuating the brakes. 8} Vehicle braking system according to Claim 6, characterized in that an air source provides the pressure medium for actuating the brakes. * 9) Fahrzeugbremseyete «with optional input, fluid-operated front and rear doors for a front, ground acting vehicle wheel group and at least one rearward acting assembly group acting on the ground, characterized by means for generating separate first and second signals which guide the turning axes correspond to the bathroom groups arranged at the front or rear, and by means of facilities that act on them Signals respond that the application of the brakes of one of the bath groups is controlled when the front, 009885/0745 - whose and rear brakes can be operated optionally « 10) Vehicle braking system according to claim 9, characterized in that the one wheel group is the rear wheel group, and that the signal-dependent devices have a device through which the effectiveness of the rear brakes belonging to the rear wheel group, depending on a predetermined Difference between the signals is to be reduced so that the speed of the rear wheel group is reduced regardless of the effectiveness of the front brakes, so that the rotation of the front wheel group is decelerated. 11) Fahrzeugbremseyetem according to claim 10, characterized through further rear brakes for a further group of rear wheels, devices for generating a further signal, which corresponds to the speed of the other wheel group and by means of the first and on address the other signals eo that the effectiveness of the other brakes is controlled so that the Rotation of the other wheel group is delayed. 009885/0745 12) FahrzeugbremBsystem according to claim 9t daduroh characterized in that each of the wheel groups has two wheels, that the signal generating devices have cooling devices that respond to the wheel rotation, so that an electrical signal is generated, that corresponds to the speed of rotation of each of the wheels and that two adder circuits are respectively responsive to the electrical signals sent to the front and rear rear wheel groups, so that the first and second signals are generated « 13j0 vehicle brake system with optionally usable, Pressure-operated front and rear brakes for a front vehicle wheel group that acts on the sod and at least one rear wheel group that acts on the ground, characterized by devices for generating separate electrical signals, each being the rotary wheels corresponding to the wheel groups fitted at the front and rear, means for electrically comparing the signals and through means that act on at least one of the wheel groups addressed the comparison to control the actuation of the brakes, if these brakes are operated optionally 009885 / 074S 14) Pahrzeugbremssystem naoh claim 13, characterized in that the comparison device a Generates control signal which corresponds to the difference between the electrical signals, and dafi the sound comparison-dependent devices have a device that is dependent on the control signal is operated so that the pressure of the pressure medium required to operate the brakes of a bath group is applied regardless of the pressure of the pressure medium acting on the brakes of the other wheel groups is exercised, is reduced 15)? Ahrzeugbrems8j8tem according to claim 14, characterized in that the one bath group consists of a rear arranged bath group, that the brake system with a pressure medium source controlled by the operator and with a first and second line device is provided, which the front or .. rear bath brakes with the source connect, and that the device has a shut-off device connected to the second line 8 device, through the dl · flow connection to steer between the rear brakes and the source » 16) 009885/0745 16) Fahrzeugbremseyetem with front and rear brakes to be actuated by the pressure of a pressure medium for a front vehicle wheel group acting on the ground and at least one rear wheel group acting on the ground, with a pressure medium source controlled by the operator and with line devices for the optional connection of the front and rear arranged wheel groups with the source, characterized by one for each wheel in the group? Associated sensing device for generating a voltage which corresponds to the tangential speed of the associated wheel, an adder circuit associated with each wheel group, which is so operatively connected to the sensing devices of the associated wheel group that an output voltage is generated which is generated for the sensors connected by the connected Voltage is indicative of a comparison circuit connected to the adding circuits of the front and rear wheel groups for generating a control voltage corresponding to the difference between the voltages of the adding circuits, and means operatively connected to the comparison circuit which are effective when the control voltage is a predetermined value reached and shows. 009885/0745 ■ shows that the tangential speed of the rear wheel group during actuation of the front and rear brakes longer than that of the front wheel group so that the fluid communication is interrupted between the rear brakes and the source. 17) Vehicle brake system with one of the pressure of a pressure medium actuated braking mechanism for a vehicle wheel acting on the ground, with one of the operator controlled pressure medium source and with a pressure medium circuit for transmission of the pressure medium from the source for actuating the lifting mechanism, characterized by one of a Motor-controlled device in the circuit for repeated pulse sensing of the pressure of the pressure medium, which is exerted by a cylindrical lock to operate the mechanism and to generate it a fluid communication between the mechanism and the source while the operator the effect of the pressure of the pressure medium on the mechanism triggers " 18) Vehicle braking system according to claim 17, characterized in that the device has a valve part owns ρ 009885/0745 possesses, which is displaceable between positions in which there is the pressure medium connection between the source and the mechanism closes or enables and that the device provides an effective has connected to the valve part motor which is so energized that it between the valve part these positions moved cylindrically. 19) vehicle braking system according to claim 18, characterized in that that the device has means which act on the movement of the valve member so are matched that the pressure of the pressure medium enclosed between the valve part and the mechanism is reduced when the valve member is moved to its closed position. 20) Vehicle braking system according to claim 19 »characterized in that that the device also set one in rotation by switching on the motor Eccentric disc has that the device for reducing the pressure is provided with a piston is, which is switched between the eccentric disc and the valve part that the valve part is moved back and forth between its positions by a rotation of the eccentric disk, and that 009885/0745 that the piston is moved back and forth by the eccentric disk and thereby arranged in the circle is that the volume of the circle between the shut-off device and the mechanism is increased, when the shut-off part is moved towards its closed position. 21) Pahrzeugbremysystem according to claim 20, characterized in that that the device is further provided with a latch part that the valve part releasably holds in its open position when the motor is not energized, and that an electromagnet is to be excited at the same time as the motor is switched on, so that the pawl part is released will · 22) vehicle braking system according to claim 21, characterized in that that the device also controlled one of the pawl part and part of the piston Has a holding circuit that prevents the motor from shutting down until the valve part moves to its open position 23) Fehrzeugbremeeyetem with one by the pressure of one Pressure medium 009885/0745 Pressure medium actuated brake mechanism, an operator controlled pressure medium source and with a pressure medium circuit that connects the source to the mechanism so that the Pressure of the pressure medium is transmitted from the source to actuate the mechanism, characterized by a valve part arranged in the circle between the source and the mechanism cylindrical blocking and opening of a flow connection between the source and the mechanism and through! executions so coordinated with the movement of the valve part that the The volume of the circle between the valve part and the mechanism is increased and decreased, when the valve part is moved into its closed or open position. 24) Vehicle braking system with one of the pressure of a pressure medium actuated braking mechanism for front and rear ground-acting vehicle wheels, with a pressure medium source, with a circuit, Kiit first and second line devices, the connect the mechanism to the source independently of one another, so that the pressure of the pressure medium to the 009885/0745 for actuation of the mechanism is transmitted and with a shut-off device controlled by the operator and arranged in the circle Control of the supply of the pressure medium to the first and second conduit means from the Source, characterized by a shut-off device, which is actuated by an electromagnet and is mounted in the one line device, which is independent is to be moved by the operator controlled valve between positions in which it (a) provides fluid communication between the valve and the associated braking mechanism and (b) the one on the associated braking mechanism Applied pressure medium can flow out, while the pressure medium flow from the source to the associated Breaea mechanism is interrupted 25) Fahreeugbremeeyitem with optional by printing a · «pressure means» to be operated front and rear lever groups for a front, on the Ground-acting vehicle wheel group and at least one rear-acting vehicle wheel group that acts on the ground Wheel group, characterized by first devices for controlling the application of the pressure de * pressure middle" 009885/0745 by means of one of the brake groups, independently from the application of pressure to the other of the brake groups and by second devices that depending on the speed of the wheel group that * belongs to the other brake group are that the first devices become less effective in controlling the pressurization when the speed of one wheel group increases 26) Vehicle braking system according to claim 16, characterized through with one of the adding circuits that go to the front wheel group belongs, associated resistance devices to reduce the extent with which the output voltage of one adding circuit increases depending on the magnitudes of the associated output voltages of the sensing devices 27) Fahrzeugbremeeyetem according to claim 16, characterized in that each · of the sensing devices of the wheel rotation dependent devices sur generating a wavy voltage, the frequency, pulse width and amplitude of the speed dew correspond to the associated wheel, and that each of the sensing devices has means for rectifying the ripple voltage before it is applied to the associated 009885/0745 - 66 - associated adding circuit is placed. 28) Vehicle braking system according to claim 16, characterized by devices connected to the comparison circuit, with devices that are so of are dependent on the tax tension that they are a Reik? / on electrical impulses with a fixed Generate a predetermined frequency, with a shut-off device, which is displaceable between two positions in which they have a flow connection between the source and the rear brakes locks, or opens, and actuators that are so of the electrical impulses depend on them to repeatedly move the shut-off device between these positions 29) Vehicle braking system for an arrangement of one Tractor and a trailer with a front and rear "rupp" acting on the messenger Zugmaechlnenrlder, with at least one group of trailer wheels acting on the ground and with Optionally operated brakes for each of the wheel groups, characterized by devices, from a speed difference between the Speed 009885/0745 The speed of the rear wheel group and the speed of the front wheel group and between the speed the trailer wheel group and the speed of the front wheel group are dependent, so that the actuation of the brakes of the rear wheel group and the Trailer wheel group independently of each other and independently of the actuation of the brakes front wheel group can be controlled. 009885/0745 Blank page