VEHICLE STATION KEEPING DEVICE

• US 3,715,721 A
• Filed: 02/23/1971
• Issued: 02/06/1973
• Est. Priority Date: 02/23/1971
• Status: Expired due to Term

• Current Assignee: Alexander Irving, Reginald Alfred Francis Priest
• Original Assignee: Alexander Irving, Reginald Alfred Francis Priest
• Inventors: Irving, Alexander, Priest, Reginald Alfred Francis
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Swann, III, Glen R.
• Application Number:
  US05/118,037
• Time in Patent Office: 714 Days
• Field of Search: 340/62,104,103 353/14,13 116/29 356/21,20,251
• US Class Current: 340/435
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: G01C 3/02 Details
• CPC Class Codes: G02B 2027/0154 with movable elements
• CPC Class Codes: G02B 2027/0169 Supporting or connecting means other than the external walls
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0149 characterised by mechanical features G02B27/0176 takes precedence

Abstract

A vehicle station keeping device provided in which the images of two fiducial marks are projected to infinity so that they can be viewed by the driver of the vehicle. The marks can be moved either continuously or in discrete steps so that the spacing between the marks is proportional to the vehicle'"'"''"'"'s speed.

Claims

1. A distance gauging device for use in a vehicle comprising:

means for producing a pair of horizontally separated fiducial marks, means for projecting to infinity an image of the fiducial marks visible to a driver of the vehicle when looking ahead, and means for varying the separation of the marks in inverse relationship to the speed of the vehicle.

2. The device as described in claim 1, wherein means for projecting said fiducial marks includes an optical system and wherein the fiducial marks as seen by the driver are images projected to infinity.

3. The device as described in claim 2 wherein the fiducial marks comprise:

a pair of non-parallel index lines, projected to infinity and wherein there further includes means for controlling the position of the index lines with respect to the optical system in response to the speed of the vehicle.

4. The device as described in claim 3 further including a drum in which the index lines are slot milled therein and a lamp is provided to illuminate the slots.

5. The device as described in claim 4 further including a speedometer movement having the drum adapted to be operatively mounted thereto so that the position of the drum varies in accordance with the speed of the vehicle.

6. The device as described in claim 1 including:

means for varying the separation of the fiducial marks visible to the driver said variance is discontinuous in response to selected discrete changes of the speed of the vehicle.

7. The device as described in claim 6, further comprising:

a matrix array of lamps, means for projecting said matrix to infinity to provide the fiducial marks and switching means for pairs of said lamps so that the spacing between switched pairs varies discontinuously in response to selected discrete changes of the speed of the vehicle.

8. The device as described in claim 7, including a tachogenerator driven in accordance with the speed of the vehicle for producing an output indicative thereof and the switching means comprises a digital voltmeter controlled in accordance with said tachogenerator output.

9. The device as described in claim 1 comprising:

a pair of illuminated graticules and lead screws each graticule mounted therein such that rotation of the lead screw in one direction causes the graticules to move together and rotation of the lead screw in the opposite direction causes the graticules to separate, servo means adopted for rotating the lead screw in such a manner that the separation of the graticules corresponds to the speed of the vehicle and means for producing an image of the graticules at infinity.

10. The device as described in claim 1 including:

a combining screen on which the image of the fiducial marks is projected.

11. The apparatus as described in claim 1 including an illuminated lens for projecting the image of the fiducial marks to infinity.