DISTANCE MEASURING DEVICE

• US 3,603,929 A
• Filed: 09/17/1969
• Issued: 09/07/1971
• Est. Priority Date: 09/17/1969
• Status: Expired due to Term

• Current Assignee: Thomas T. Drysdale
• Original Assignee: Thomas T. Drysdale
• Inventors: Drysdale, Thomas T.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Cohen, Howard
• Application Number:
  US04/858,774
• Time in Patent Office: 720 Days
• Field of Search: 340/104,103,97,98,87 356/29 73/489,490
• US Class Current: 340/435
• CPC Class Codes: B60R 1/00 Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
• CPC Class Codes: G01C 3/22 using a parallactic triangle with variable angles and a base of fixed length at, near, or formed by the object

Abstract

The gauging means is installed in a recess in the top of the dash of an automobile and consists of horizontally relatively movable strips geared to a speedometer means to assume positions the spacing of which bears a relationship to the speed of the car. A phantom image of the two gauge strips is projected upon and reflected from the glass windshield in a position approximately at eye-level and in the line of vision toward a car ahead. The eyes of the observer-driver are naturally focused on the car ahead and thus a double image of the gauge strips is seen and due to the overlap of vision, a centrally disposed composite phantom strip of a length variable according to the speed of the car appears in substantial registry with the view of the car ahead. By proper calibration of the gauge, it will be seen that when the apparent lateral dimension of the car ahead exceeds or falls short of the length of the phantom overlapping image of the gauge strips, the operator can determine whether he should reduce his speed and fall back or whether he can safely increase his speed. The calibration is such that when the length of the gauge image is approximately equal to the observed width of the car ahead, the spacing of the two vehicles is proper for the indicated speed.

Claims

1. Apparatus for installation in a vehicle for indicating to the operator the attainment of the proper safe distance from a vehicle ahead for any given speed, said apparatus comprising a gauging device mounted in the first named vehicle, means for changing a transverse dimension of said device in relation to the speed off the vehicle, said device calibrated to correspond at a given speed to an apparent transverse dimension of the vehicle ahead when the spacing of the two vehicles is proper for safety at that speed, and means for disposing said device so that its transverse dimension may be readily compared with the apparent corresponding transverse dimension of the vehicle ahead as observed by said driver.

2. The apparatus as set forth in claim 1, in which, when the eyes of the operator are focused on the vehicle ahead, an out-of-focus double image of the gauging device is seen, and a portion of said double image, variable in transverse dimension according to the speed of the first named vehicle, is employed for such comparison.

3. The apparatus as set forth in claim 1 in which said device comprises a pair of aligned strips in approximate abutting end-to-end relationship when the vehicle is stationary but movable apart distances related to the speed of the vehicle, whereby when the driver'"'"''"'"'s eyes are focused on the vehicle ahead a composite phantom image appears in the line of sight for comparison with the dimension of the vehicle ahead, due to the out-of-focus view of the gauge device.

4. An apparatus as set forth in claim 2 in which said device comprises a pair of aligned strips in substantial abutting end-to-end relationship when the vehicle is stationary but movable apart distances related to the speed of the vehicle, whereby when the driver'"'"''"'"'s eyes are focused on the vehicle ahead, a composite phantom image appears in the windshield for comparison with the dimension of the vehicle ahead, due to the out-of-focus view of the reflection of the gauge device.

5. The device as set forth in claim 1 in which said device comprises a pair of aligned strips in substantial abutting end-to-end relationship when the vehicle is stationary but movable apart distances related to the speed of the vehicle, and there are provided means for slidingly mounting said strips in the vehicle, spring restrained means operatively connected with the strips and means for urging said spring restrained means against such restraint in a ratio to the speed of the vehicle.

6. The device as set forth in claim 5 in which said device is mounted on top of the instrument panel of the first named vehicle and its image reflected from the windshield in the approximate line of sight of the driver toward the vehicle ahead, and there are provided means affording back illumination of said strips and means for controlling the intensity of illumination according to the natural light available at a given time of the day, and for variably illuminating the respective strips according to any variation in the visual condition of the right and left eyes of the driver

7. The apparatus as set froth in claim 4 in which there are provided means affording back illumination of said strips and means for controlling the intensity of illumination according to the natural light available at a given time of the day, and for variably illuminating the respective strips according to any variation in the visual condition of the right and left eyes of the driver.

8. The device as set froth in claim 5 in which said device is mounted on top of the instrument panel of the first named vehicle and its image reflected from the windshield in the approximate line of sight of the driver toward the vehicle ahead, and there are provided means for back illumination of said strips, said strips being of translucent material, opaque strips of flexible material connected with the mutually facing ends of said gauge strips and brought into virtual contact at the mid portion of the device, and having their ends wound around spring restrained spools, whereby light from the illuminating means is projected only through said gauge strips.