WO2015145460A1

WO2015145460A1 - Mechanical instrument cluster with digital display type aesthetics

Info

Publication number: WO2015145460A1
Application number: PCT/IN2015/000140
Authority: WO
Inventors: Kumaravadivelu GANESAN
Original assignee: Pricol Limited
Priority date: 2014-03-28
Filing date: 2015-03-25
Publication date: 2015-10-01

Abstract

The present invention discloses a mechanical instrument cluster used in automobiles with digital display type aesthetics capable of displaying speedometer digits like Liquid Crystal Display (LCD) without using LCD or any other electronic components. A circular dial (5) in scripted with the speed detail and illuminated displays the speed information as digital display. A semicircular dial (6) having color print displays the fuel level as bar type indication.

Description

MECHANICAL INSTRUMENT CLUSTER WITH DIGITAL DISPLAY TYPE

AESTHETICS

FIELD OF INVENTION

The present invention relates to a mechanical instrument cluster used in automobiles. More particularly, the present invention relates to a mechanical instrument cluster used in automobiles with digital display type aesthetics capable of displaying speedometer digits like Liquid Crystal Display (LCD) without using LCD or any other electronic components. Further, the present invention relates to a mechanical instrument cluster with digital display type aesthetics provided with dynamic dial plate integrated with speedometer system. DESCRIPTION OF PRIOR ART

Generally, an instrument cluster used in an automobile comprising of a set of instruments, which includes speedometer, odometer and fuel level indicator. While the speedometer display the current speed of the vehicle, the odometer display the distance traveled by a vehicle. The fuel level indicator is provided to indicate the quantity of the fuel left inside the fuel tank to the driver of the vehicle so that he can plan refilling. These instruments display the appropriate parameters either in analog form Or in digital form according to their construction.

There are two types of speedometers namely mechanical and electronic which is in common use. The mechanical speedometer works based on eddy-current principle. To measure the speed of the vehicle one must be able to measure the rotational speed of the wheels or the transmission and send that information to a measuring device known as speedometer. In general, the measurement takes place in the transmission. A drive cable is used to measure the rotational speed generated by the transmission. The drive cable comprises of a number of superimposed, tightly wound, helical coil springs wrapped around a center wire known as mandrel. Because of its construction, the drive cable is very flexible and can be bent, without fracture, to a very small radius. The drive cable is connected to a set of gears in the transmission, so that when the vehicle moves, the gears turn the mandrel inside the flexible shaft

The mandrel then communicates the rotational speed of the transmission down the length of the cable to the driven part of the speedometer. The speedometer houses a cup-shaped metal piece known as the speed cup. A permanent magnet is disposed inside the speed cup and the drive cable via a spiral gear is attached to the permanent magnet. Normally a needle is attached to the speed cup and is held in place by a hairspring. The needle is swing able over a dial in scripted with a range of numbers from zero to an upper limit. The movement of the needle over the dial could be viewed through a transparent member fitted to the face of the speedometer. When the vehicle is in motion, approximately at a constant speed, the transmission and driveshaft are rotating at a speed that corresponds to the vehicle speed and the mandrel in the speedometer's drive cable is also rotating at a pre-determined ratio and the permanent magnet attached at the other end of the drive cable is also rotating. As the permanent magnet spins, it sets up a rotating magnetic field and creates forces that act on the speed cup, said forces cause electrical current to flow in the speed cup as small rotating eddies, known as eddy currents.

The eddy currents create a drag torque on the speed cup and the needle attached to the speed cup also turn in the same direction as that of the magnetic field but only as far as the hairspring will allow it. The needle on the speed cup comes to a rest where the opposing force of the hairspring balances the force created by the revolving magnet. When the vehicle is at standstill, the hairspring holds the needle at zero.

The electronic speedometers are used in modern day vehicles. In the electronic speedometer, the drive cable is no longer present and it receives its data from a vehicle speed sensor (VSS). The VSS is mounted to transmission output shaft or to a crankshaft and consists of a toothed metal disk and a stationary detector that covers a magnetic coil. As the teeth move past the coil, they "interrupt" the magnetic field, creating a series of pulses that are sent to the microprocessor of the vehicle, which determine the speed of the vehicle from the input pulse frequency. Circuit electronics in the vehicle are designed to display the speed either on a digital screen or on a typical analog system with a needle and dial.

Although vehicles are manufactured with digital display rather than analog system with the needle and dial, the speedometers with digital display capable of indicating the speed of the vehicle as digital display is more expensive by virtue of its construction feature.

It will be advantageous to provide a cost effective and user friendly mechanical instrument cluster that will display the speedometer digits like LCD without electronic components such as LCD, Printed Circuit Board (PCB) and stepper motor. OBJECTS OF INVENTION

One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention.

It is the primary object of the present invention to provide a mechanical instrument cluster with digital display type aesthetics capable of displaying the speedometer digits like Liquid Crystal Display (LCD) without using electronic components such as LCD, PCB and stepper motor.

It is another object of the present invention to provide a mechanical instrument cluster with digital display type aesthetics, which can display the analog numbers by magnifying its original size and make it as look like a segment display in an LCD.

It is another object of the present invention to provide a mechanical instrument cluster with digital display type aesthetics with a dial illumination. It is another object of the present invention to provide a mechanical instrument cluster with digital display type aesthetics provided with dynamic dial plate integrated with speedometer system.

It is another object of the present invention to provide a mechanical instrument cluster with digital display type aesthetics provided with fuel level indication in bar system same as Liquid Crystal Display (LCD).

SUMMARY OF INVENTION

Thus according to the basic aspect of the present invention there is provided a mechanical instrument cluster with digital display type aesthetics comprising of: a case housing comprising a rotatably supported speed cup fitted with a permanent magnet and held by a hairspring; a drive cable disposed to drivingly connect the speed cup fitted with the permanent magnet to the transmission of the vehicle; the case housing further rotatably support the axis of the fuel level system and a transparent cover is fitted on the top of the case housing for visualizing the display of the instrument cluster by driver of the vehicle characterized in that:

a fixed dial provided with windows is fitted to the case housing ;

a circular dial provided with a range of numbers from zero to a pre-determined upper limit in scripted at a pre-defined radius having a pre-determined radial distance between them is coaxially mounted on the speed cup; a semicircular dial plate provided with at least one colour printing of pre-defined arc length and width is mounted on the axis of fuel gauge system ; and

a magnifier is fitted over the window of the fixed dial fitted to the case housing,

wherein the circular dial is illuminated and the scripted numbers of the circular dial is magnified by another magnifier fitted on the window for the display of vehicle speed.

According to another aspect of the invention one of the scripted numbers of the circular dial is visible through the window provided on the fixed dial fitted to the case housing .

According to another aspect of the invention the semicircular dial plate provided with the colour printing is arranged at a pre-determined radius to indicate different levels of fuel condition.

According to another aspect of the invention the magnifier magnifies and displays illuminated colour printing of the semicircular dial plate as coloured bar segment.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 : illustrates the isometric view of the mechanical instrument cluster according to the present invention.

Figure 2: illustrates the arrangement of the dial fitted with the magnifier of the mechanical instrument cluster according to the present invention.

Figure 3: illustrates the arrangement of the semicircular dial fitted with the magnifier and the driving mechanism from fuel gauge system according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

The present invention as, discussed hereinbefore relates to a mechanical instrument cluster used in automobiles which is capable of displaying speedometer digits like Liquid Crystal Display (LCD) without using LCD or any other electronic components. The analog type speedometer known in the art houses a cup-shaped metal piece known as speed cup. A permanent magnet is disposed inside the speed cup and first end of a drive cable via a spiral gear is attached to it. Normally a needle is attached to the speed cup and is held in place by a hairspring attached to the speed cup. The needle is swing able over a dial in scripted with a range of numbers from zero to an upper limit corresponding to the speed of the vehicle. The movement of the needle over the dial could be viewed by the driver of the vehicle through a transparent member fitted to the face of the speedometer. Likewise the fuel level is indicated by a needle attached to the axis of the fuel level measurement system over a dial.

Referring to Figures 1 and 2, in the mechanical instrument cluster with digital display type aesthetics according to the present invention, the needle is eliminated and a circular dial [5] provided with a range of numbers from zero to a pre-determined upper limit in scripted is fitted to a speed cup such that the radial movement of the speed cup incorporates radial movement to the circular dial [5] to display the vehicle speed as shown in Figure 2. Similarly for indicating the fuel level, the needle is eliminated and a semi-circular dial [6] provided with colour prints [10] is attached to the axis of the fuel level system for the display of fuel level as shown in Figure 3.

The mechanical instrument cluster with digital display type aesthetics comprising of a fixed dial [1] provided with a first window [la] of pre determined size and shape, preferably circular iri shape which is located at a pre-determined location and is fitted on the on a case housing [2]. A speed cup fitted with a permanent magnet is arranged inside the case housing [2] and rotatably supported, and retained in position with the help of a hair spring as known in the art. A circular dial [5] is coaxially mounted on the speed cup. The circular dial [5] is constructed using durable light weight transparent material and is illuminated from the bottom side. As known in the art, the first end of the drive cable of the speedometer drive system is connected to the permanent magnet fitted to the speed cup and the second end to the transmission of the vehicle.

The rotation of the drive cable produces a drag torque on the speed cup fitted with permanent magnet and the eddy current developed tend to rotate the speed cup and the circular dial [5]. The speed cup comes to rest when the opposing force of the hairspring attached to the speed cup balances the force created by the permanent magnet. Whenever the speed cup comes to rest, the circular dial [5] fitted to it also comes to rest. The circular dial [5] is provided with a range of numbers from zero to a pre-determined upper limit in scripted at a pre-defined radius and at a predetermined radial distance between them. Light reflecting paints may be advantageously used for in scripts. The circular dial [5] is illuminated by any one of the illuminating arrangements known in the art. Preferably the illuminating arrangement is positioned underneath the fixed dial [1].

A magnifier [4] is fitted over the window [la] of the case housing [2]. One of the scripted numbers of the circular dial [5] is visible through the magnifier [4] provided on the case housing [2] as a digital display according to the speed of the vehicle on which the mechanical instrument cluster is fitted. Referring to Figures 1 and 3, the mechanical instrument cluster according to the present invention further comprising of a semicircular dial plate [6] for the indication of the fuel level in conjunction with illuminating arrangement and a magnifier [9]. The fixed dial [1] which is fitted on the on the case housing [2] is further provided with a second window [lb] of predetermined size and shape and arranged at a pre determined location.

The axis [7] of the fuel gauge system [8] is rotatably supported within the case housing [2] as known in the art such that the axis [7] of the fuel gauge system makes angular displacement according to the fuel level. The semicircular dial plate [6] of pre determined size is mounted on the axis [7] of the fuel gauge system [8] such that semicircular dial plate [6] also under goes angular displacement according to the fuel level. The semicircular dial plate [6] is provided with at least one colour printing [10] of pre-defined arc length and width and arranged at a pre-determined radius to indicate the fuel level.

For example, the colour printing [10] on the semicircular dial plate [6] may be green, yellow and red to indicate the different level conditions full, half and empty respectively. The semicircular dial plate [6] is illuminated by any one of the illuminating arrangements known in the art.

The magnifier [9] is fitted over the window [lb] of the case housing [2] to magnify and display the illuminated colour printing [10] of the semicircular dial plate [6] as coloured bar segment as shown in Figure 3. The width of the colour printing [10] is selected such that though the dial plate [6] makes radial movement, the fuel level is indicated like a bar system [3] as shown in Figure 1 through the window [lb] of the fixed dial [1] fitted to the case housing [2].

The display of the illuminated in scripts of the circular dial [5] and the illuminated colour prints [10] through the magnifiers [4] and [9] provides the digital display type aesthetics of the vehicle speed and the fuel level.

Though this invention is hereinbefore described and illustrated with reference to specific embodiments, obvious alterations and modifications known to persons skilled in the art are well within the scope of the appended claims.

Claims

WE CLAIM:

L A mechanical instrument cluster with digital display type aesthetics comprising of:

a case housing [2] comprising a rotatably supported speed cup fitted with a permanent magnet and held by a hairspring; a drive cable disposed to drivingly connect the speed cup fitted with the permanent magnet to the transmission of the vehicle; the case housing [2] further rotatably support the axis of the fuel level system and a transparent cover is fitted on the top of the case housing [2] for visualizing the display of the instrument cluster by driver of the vehicle characterized in that: a fixed dial [1] provided with windows [la ,1b] is fitted to the case housing [2];

a circular dial [5] provided with a range of numbers from zero to a pre-determined upper limit in scripted at a pre-defined radius having a pre-determined radial distance between them is coaxially mounted on the speed cup;

a semicircular dial plate [6] provided with at least one colour printing [10] of pre-defined arc length and width is mounted on the axis [7] of fuel gauge system [8]; and

a magnifier [9] is fitted over the window [lb] of the fixed dial [1] fitted to the case housing, wherein the circular dial [5] is illuminated and the scripted numbers of the circular dial [5] is magnified by another magnifier [4] fitted on the window [la] for the display of vehicle speed.

2. The mechanical instrument cluster as claimed in claim 1, wherein one of the scripted numbers of the circular dial [5] is visible through the window [la] provided on the fixed dial [1] fitted to the case housing [2].

3. The mechanical instrument cluster as claimed in claim 1, wherein the semicircular dial plate [6] provided with the colour printing [10] is arranged at a pre-determined radius to indicate different levels of fuel condition.

4. The mechanical instrument cluster as claimed in claim 1, wherein the magnifier [9] magnifies and displays illuminated colour printing [10] of the semicircular dial plate [6] as coloured bar segment.