Dial speed indicator with two pointers indicating an actual speed and a reference speed

1. A speed indicator, comprising:

a dial plate supporting a dial;

a first pointer indicating the actual speed, rotated in front of the dial;

a second pointer indicating a reference speed, rotated behind the dial and including an end portion visible at the outer edge of the dial; and

means for illuminating the first and second pointers and the dial;

wherein the means for illuminating comprises a single source of illumination common to the first pointer, the second pointer and the dial;

wherein the dial plate is mounted on a light pipe and mounted in a first light box, and wherein the first pointer is light-transmitting, the second pointer is light-transmitting, and mounted in a second light box at the rear of the first light box; and

a printed circuit board, on which is mounted the source of illumination, being provided at the rear of the second pointer.

2. The speed indicator of claim 1 , wherein the first and second pointers are rotated by two concentric drive shafts and rotated by a single motor mounted on the printed circuit board.

3. The speed indicator of claim 2 , wherein the second pointer comprises an arm, of which the first end comprises a hub for receiving its drive shaft and the second end comprises an angled portion, of which the end is visible at the outer edge of the dial.

4. The speed indicator of claim 3 , wherein the arm of the second pointer comprises, near its first end, at least one inclined face which partially reflects the light emitted by the source of illumination into the arm and partially allows it to pass towards the light pipe, via a cut-out made in the first light box.

5. The speed indicator of claim 4 , wherein the light pipe is arranged to diffuse the light produced by the source of illumination, to illuminate the dial, and to allow a part of this light to pass for the illumination of the first pointer.

6. The speed indicator of claim 5 , wherein the light pipe comprises a convex light-transmitting lens, including a tapered cut-out for diffusing a part of the light emitted by the source of illumination into the lens, and allowing a part of this light to pass towards the first pointer.

7. The speed indicator of claim 6 , wherein the source of illumination comprises at least one light-emitting diode.

8. The speed indicator of claim 7 , wherein the speed indicator is for an instrument panel of a motor vehicle.

9. The speed indicator of claim 1 , wherein the second pointer comprises an arm, of which the first end comprises a hub for receiving its drive shaft and the second end comprises an angled portion, of which the end is visible at the outer edge of the dial.

10. The speed indicator of claim 1 , wherein the source of illumination comprises at least one light-emitting diode.

11. The speed indicator of claim 1 , wherein the speed indicator is for an instrument panel of a motor vehicle.

12. A speed indicator, comprising:

a dial plate supporting a dial;

a first pointer indicating a first speed, wherein the first pointer is configured to rotate in front of the dial;

a second pointer indicating a second speed, wherein the second pointer is configured to rotate behind the dial and wherein the second pointer includes an end portion visible at the outer edge of the dial; and

a light source configured to illuminate the first pointer, second pointer and the dial;

wherein the dial plate is mounted on a light pipe in a first light box;

wherein the first pointer is illuminable, the second pointer is illuminable, and mounted in a second light box at the rear of the first light box; and

a control circuit to which the light source is mounted is provided at the rear of the second pointer.

13. The speed indicator of claim 12 , wherein the first and second pointers are rotated by two concentric drive shafts attached to a single motor, governed by the control circuit.

14. The speed indicator of claim 13 , wherein the second pointer comprises an arm, of which the first end comprises a hub for receiving its drive shaft and the second end comprises an angled portion, of which the end is visible at the outer edge of the dial.

15. The speed indicator of claim 14 , wherein the arm of the second pointer comprises at least one inclined face which at least partially reflects the light into the arm and at least partially allows it to pass towards the light pipe, via a cut-out made in the first light box.

16. The speed indicator of claim 15 , wherein the light pipe is arranged to diffuse light, to illuminate the dial, and to at least partially illuminate the first pointer.

17. The speed indicator of claim 16 , wherein the light pipe comprises a convex light-transmitting lens, including a tapered cut-out for diffusing a part of the light emitted by the source of illumination into the lens, and allowing a part of this light to pass towards the first pointer.

18. An indicator for a vehicle instrument cluster, comprising:

an electric motor;

a plurality of pointers concentrically mounted with respect to the instrument cluster;

a plurality of drive shafts connecting the pointers to the electric motor;

a dial mounted between at least two pointers in the plurality of pointers;

a first light box attached to the dial and configured to at least partially conceal light in at least one pointer; and

a light source configured to provide light to the plurality of pointers;

wherein one pointer has a radius that is longer than a radius of the another pointer and a radius of the dial, and wherein the one pointer is mounted behind the dial so that the one pointer is at least partially concealed behind the dial;

wherein the indicator shows vehicle speed and wherein one pointer shows the actual vehicle speed and another pointer shows a reference speed;

wherein the dial is mounted on a light pipe in a first light box;

wherein the first pointer is illuminable, the second pointer is illuminable, and mounted in a second light box at the rear of the first light box; and

a control circuit to which the light source is mounted is provided at the rear of the second pointer.

19. The indicator of claim 18 , wherein the at least one pointer in the plurality of pointers comprises a reflective surface to guide light from one end of the at least one pointer to a second end of the at least one pointer.

20. The indicator of claim 18 , wherein the light source is center-mounted with respect to the dial.