GB1593896A - Speed control devices for motor vehicles - Google Patents

Description

(54) IMPROVEMENTS IN SPEED CONTROL DEVICES FOR MOTOR VEHICLES (71) We, VDO ADOLF SCHIND LING AG, of 103 Graftstrasse, Frankfurt/ Main, Germany, a body corporate organized according to the laws of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a speed control device for motor vehicles, having an electrical controller generating a control signal which is a function of the control deviation, and an electrical correcting device responsive to the control signal and which comprises a rotatably mounted element actuating correcting means acting on the throttle valve of the engine, which said element is driven via transmission by an electric motor, and a variable resistor the wiper of which is coupled to one of the rotating components of the correcting device.

Speed control devices of this type are already known, (see for example British Patent Specification No. 1,277,276) which have a conventional rotary rheostat as the variable resistor, the correcting shaft of which is coupled to one of the rotating shafts of the correcting device. The provision of such a rotary rheostat and its coaxial arrangement relative to a rotating shaft, means that the electrical correcting device occupies a large volume which is disadvantageous. It is true that this can be obviated by effecting the drive of the rotary rheostat via a gear wheel transmission system having intersecting or crossing axes, but such an arrangement involves an undesirable further increase of the cost of manufacture which is already quite high due to the use of a conventional rotary rheostat.

It is an object of the present invention to overcome partially or wholly these disadvantages by providing a speed control device which has the smallest possible structural volume and the lowest possible manufacturing costs.

According to the present invention there is provided a speed control device for motor vehicles including an electrical controller generating a control signal which is a function of the control deviation, and an electrical correcting device responsive to the control signal, said correcting device including: a rotatable element, means connected to the rotary element for actuating the throttle valve of the engine; drive means for rotating said element; a variable resistor having at least one resistance track arranged on the rotatable element; and at least two wipers insulated from each other for making contact with the track or tracks on said rotatable element.

The above measure permits extremely compact and space-saving construction of the correcting device, since now the individual elements of the variable resistor are completely integrated in the correcting device. To this is added that a resistor which is variable in this manner involves a mode of construction which requires substantially less components and is therefore more advantageous from the point of view of cost than does a conventional rotary rheostat.

In a preferred form, at least one current supply track is arranged on the rotating element and connected to the resistance track or tracks. Such an embodiment has the advantage that an especially high resistance variation per degree of rotation can be achieved.

It has been found to be advantageous to secure the two wipers in a holder which is insertable in the housing from the exterior.

Thereby, not only is the assembly of the variable resistor facilitated but maintainence work to the wipers is substantially facilitated.

It has been found to be expedient to arrange the tracks on the rotatably mounted element. This has the advantage that a relatively large end face for the resistance or current supply tracks is available, and this facilitates the attachment of the tracks which are printed or adhesively secured thereto.

The present invention will now be described in greater detail by way of example with reference to the accompanying drawing, wherein: Figure I is a partially sectioned lateral elevation of the correcting device and of the speed control device; and Figure 2 is a sectional view through the correcting device shown in Figure 1, taken along the line II-II.

Referring to the drawings, the correcting device and speed control device are housed in a housing 1 made from a plastics material and having a cylindrical projection 2 extending from the upper part of the housing 1. A D.C. motor 3 is housed within the cylindrical projection 2.

The D.C. motor 3 is provided with a shaft 4 which projects through an aperture in a closure cover 5 and carries at its free end a pinion 6. The closure cover 5 divides the cylindrical projection 2 from the rest of the housing 1. Mounted in the closure cover 5 and in a cover 7 of the housing 1 is a shaft 8 on which is arranged a rope pulley 9 for the winding on and off of the correcting means 10 in the form of a rope. The rope 10 is secured at one end to the rope pulley 9 and is guided to the exterior of the housing 1 through an aperture 11 formed therein and connected at its other end to the throttle control rod (not shown) of the motor vehicle.

A gear wheel 12 is mounted in the rope pulley 9, the gear wheel 12 is driven by the pinion 6 via gear wheels 13 and 14. The ends of the shaft 15 carrying the gear wheels 13 and 14 are mounted in the housing 1 and the cover 7 respectively.

A variable rotary rheostat 16, which is provided for achieving a proportional control, comprises two resistance tracks 17 and 18 connected to each other at one end. The tracks 17 and 18 are printed or adhesively secured on one end face of the rope pulley 9. The two resistance tracks 17 and 18 are arranged concentric to each other. Wipers 19 and 20 are secured to a holder 21 and make contact with respective tracks 18 and 17. The holder 21 is designed so that it can be inserted latchingly into an aperture 22 in the housing 1. In order to ensure entirely satisfactory positioning of the wipers 19 and 20 on the resistance tracks 18 and 17, the cross-section of the holder 21 is rectangular and so is the aperture 22 formed in the housing 1. Out of the end face remote from the wipers 19 and 20 of the holder 21 project two terminal tabs 23 and 24.

The wiring of the correcting device in the framework of the speed control device can be effected in known manner.

In an alternative form the arrangement may comprise only one resistance track, there being a concentric current track replacing the other resistance track. Furthermore the arrangement may comprise more than two resistance tracks and more than one current track.

WHAT WE CLAIM IS: 1. A speed control device for motor vehicles including an electrical controller generating a control signal which is a function of the control deviation, and an electrical correcting device responsive to the control signal, said correcting device including: a rotatable element; means connected to the rotating element for actuating the throttle valve of the engine; drive means for rotating said element; a variable resistor having at least one resistance track arranged on the rotatable element; and at least two wipers insulated from each other for making contact with the track or tracks on said rotatable element.

2. A speed control device according to claim 1, wherein there is provided at least one current supply track arranged on the rotating element and connected to the resistance track or tracks.

3. A speed control device according to claim 1 or 2, wherein the two wipers are secured in a holder which is arranged to be inserted into a housing of the correcting device from the exterior.

4. A speed control device according to any one of the preceding claims, wherein the tracks are printed or adhesively secured to one end face of a rope pulley constituting said rotatably mounted element.

5. A speed control device for motor vehicles constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. arrange the tracks on the rotatably mounted element. This has the advantage that a relatively large end face for the resistance or current supply tracks is available, and this facilitates the attachment of the tracks which are printed or adhesively secured thereto. The present invention will now be described in greater detail by way of example with reference to the accompanying drawing, wherein: Figure I is a partially sectioned lateral elevation of the correcting device and of the speed control device; and Figure 2 is a sectional view through the correcting device shown in Figure 1, taken along the line II-II. Referring to the drawings, the correcting device and speed control device are housed in a housing 1 made from a plastics material and having a cylindrical projection 2 extending from the upper part of the housing 1. A D.C. motor 3 is housed within the cylindrical projection 2. The D.C. motor 3 is provided with a shaft 4 which projects through an aperture in a closure cover 5 and carries at its free end a pinion 6. The closure cover 5 divides the cylindrical projection 2 from the rest of the housing 1. Mounted in the closure cover 5 and in a cover 7 of the housing 1 is a shaft 8 on which is arranged a rope pulley 9 for the winding on and off of the correcting means 10 in the form of a rope. The rope 10 is secured at one end to the rope pulley 9 and is guided to the exterior of the housing 1 through an aperture 11 formed therein and connected at its other end to the throttle control rod (not shown) of the motor vehicle. A gear wheel 12 is mounted in the rope pulley 9, the gear wheel 12 is driven by the pinion 6 via gear wheels 13 and 14. The ends of the shaft 15 carrying the gear wheels 13 and 14 are mounted in the housing 1 and the cover 7 respectively. A variable rotary rheostat 16, which is provided for achieving a proportional control, comprises two resistance tracks 17 and 18 connected to each other at one end. The tracks 17 and 18 are printed or adhesively secured on one end face of the rope pulley 9. The two resistance tracks 17 and 18 are arranged concentric to each other. Wipers 19 and 20 are secured to a holder 21 and make contact with respective tracks 18 and 17. The holder 21 is designed so that it can be inserted latchingly into an aperture 22 in the housing 1. In order to ensure entirely satisfactory positioning of the wipers 19 and 20 on the resistance tracks 18 and 17, the cross-section of the holder 21 is rectangular and so is the aperture 22 formed in the housing 1. Out of the end face remote from the wipers 19 and 20 of the holder 21 project two terminal tabs 23 and 24. The wiring of the correcting device in the framework of the speed control device can be effected in known manner. In an alternative form the arrangement may comprise only one resistance track, there being a concentric current track replacing the other resistance track. Furthermore the arrangement may comprise more than two resistance tracks and more than one current track. WHAT WE CLAIM IS:

1. A speed control device for motor vehicles including an electrical controller generating a control signal which is a function of the control deviation, and an electrical correcting device responsive to the control signal, said correcting device including: a rotatable element; means connected to the rotating element for actuating the throttle valve of the engine; drive means for rotating said element; a variable resistor having at least one resistance track arranged on the rotatable element; and at least two wipers insulated from each other for making contact with the track or tracks on said rotatable element.

2. A speed control device according to claim 1, wherein there is provided at least one current supply track arranged on the rotating element and connected to the resistance track or tracks.

3. A speed control device according to claim 1 or 2, wherein the two wipers are secured in a holder which is arranged to be inserted into a housing of the correcting device from the exterior.

4. A speed control device according to any one of the preceding claims, wherein the tracks are printed or adhesively secured to one end face of a rope pulley constituting said rotatably mounted element.

5. A speed control device for motor vehicles constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.