PACING SYSTEM FOR CONVEYANCES

• US 3,750,099 A
• Filed: 03/17/1972
• Issued: 07/31/1973
• Est. Priority Date: 03/17/1972
• Status: Expired due to Term

• Current Assignee: Robert E. Proctor
• Original Assignee: Robert E. Proctor
• Inventors: Proctor, Robert E.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US05/235,757
• Time in Patent Office: 501 Days
• Field of Search: 240/1.2 244/114 356/23 340/22,25,31R,35,36,41,26
• US Class Current: 340/932
• CPC Class Codes: E01F 9/20 Use of light guides, e.g. fibre-optic devices
• CPC Class Codes: G08G 1/07 Controlling traffic signals
• CPC Class Codes: G08G 5/0026 located on the ground
• CPC Class Codes: G08G 5/06 for control when on the ground
• CPC Class Codes: G08G 5/065 Navigation or guidance aids, e.g. for taxiing or rolling
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

Systems for pacing the movement of conveyances are disclosed, each system being comprised of a stationary strip of equally spaced bars, the longitudinal axis of the bars being transverse to the direction of traffic (either erect on one side or horizontal in the path of the traffic, such as on an airport runway) and means for intermittently illuminating them simultaneously at a selected frequency, where the frequency is selected to produce a stroboscopic effect on an observer moving parallel to the strip of such bars, such that only at a predetermined velocity will the bars appear to be motionless, i.e., appear to have a velocity of zero relative to the moving observer.

Claims

1. Apparatus for pacing the movement of conveyances in a given direction comprised of a strip of equally spaced and stationary bars disposed parallel to said given direction, said bars being more visible to an observer in said conveyance when illuminated than the background surrounding said bars, means for intermittently illuminating said bars simultaneously at a predetermined frequency to produce a stroboscopic effect on an observer moving in one of said conveyances such that when the velocity of said conveyance is greater than said predetermined velocity within a given range of higher velocities, it will appear to the observer that said bars are moving toward the observer, when the velocity of said conveyances is less than said predetermined velocity within a given range of lower velocities, it will appear to the observer that said bars are moving away from said conveyance in the direction of motion of said conveyance, and when the velocity of said conveyance is equal to said predetermined velocity, it will appear to the observer that said bars are stationary relative to said conveyance.

2. Apparatus as defined in claim 1, wherein said bars are speced apart a distance B and said frequency is selected for said desired velocity V to satisfy a relationship (VB/f) N where N is an integer, except zero, or any member of a set of fractions ( 1/2 , 1/3 , 1/4 ...)

3. Apparatus as defined in claim 2, wherein said frequency is chosen sufficiently high to be within the requirements of the persistence of vision.

4. Apparatus as defined in claim 3, wherein said means is comprised of individual flashed light sources mounted in fixtures.

5. Apparatus as defined in claim 3, wherein said means is comprised of a flashing light source carried by said conveyance.

6. Apparatus as defined in claim 3, wherein said means is comprised of an opaque conduit having said bars formed as apertures in said conduit, each aperature beinG covered by a translucent shield, and floodlights for filling said conduit with flashes of light from each end of said conduit.

7. Apparatus as defined in claim 6 wherein said conduit has a planar back wall diverging slightly from a parallel position with a planar front wall having said apertures.