Equipment for maintaining the spacing of track-bound vehicles

• US 4,473,787 A
• Filed: 06/14/1982
• Issued: 09/25/1984
• Est. Priority Date: 11/14/1980
• Status: Expired due to Fees

• Current Assignee: Digitron AG (Midea Group Co., Ltd)
• Original Assignee: Inventio AG (Schindler Holding AG)
• Inventors: Schick, Jean-Claude
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Ro, Bentsu
• Application Number:
  US06/395,033
• Time in Patent Office: 834 Days
• Field of Search: 367/909, 340/33, 340/34, 318/480, 318/587, 318/70, 356/4, 356/28, 343/7 VC
• US Class Current: 318/587
• CPC Class Codes: B61L 23/34 for indicating the distance between vehicles or trains by the transmission of signals therebetween
• CPC Class Codes: Y10S 367/909 Collision avoidance

Abstract

The equipment for maintaining the spacing of track-bound vehicles (1) shall prevent collisions of the vehicles (1). For this, light emitters radiating rearwardly and laterally in desired directions are provided at the rear on the vehicles (1) and light receivers receiving from in front and from the sides in desired directions are provided at the front on the vehicles (1). A drive control reduces the speed of a vehicle (1) with increasing received light intensity, i.e. with decreasing spacing from the vehicle (1) travelling immediately ahead. The equipment is usable for floor conveying plants with vehicles (1) travelling at small spacings one behind the other. An embodiment of the equipment is suitable for vehicles (1) travelling forwardly and rearwardly. A further embodiment of the equipment is suitable for vehicles (1) on neighboring travel paths. Special measures are provided for compensation of the influences of ambient light.

Claims

1. Equipment for maintaining the spacing of track-bound vehicles having a front end and a rear end with respect to a vehicle travel direction, each vehicle being driven along a track by respective drive means in a selected one of two opposed directions of travel, said equipment comprising:

a light emitter mounted at each end of each one of said vehicles and operable to uniformly longitudinally and laterally emit light in predetermined directions;

said light emitter being operable to emit modulated light;

a light receiver mounted at each end of each one of said vehicles and operable to receive light emitted uniformly and laterally towards said light receiver;

said light receiver being operable to receive incoming modulated light and to generate demodulated output signals;

a first switching device acting on said light emitter;

a second switching device acting on said light receiver;

said first and said second switching devices of each vehicle cutting-off the light emitted to one side of said light emitter and the reception of said emitted light at a corresponding side of said light receiver, respectively;

a drive control for each said drive means of the vehicles;

said first and said second switching devices being operated upon by said drive control of said vehicle; and

said drive control of said trailing vehicle being operable in response to the intensity of said light received by said light receiver on said trailing vehicle and emitted by said light emitter on said leading vehicle, so that the speed of said trailing vehicle is reduced as said intensity of said light received by said light receiver on said trailing vehicle increases.

2. Equipment for maintaining the spacing of track-bound vehicles having a front end and a rear end with respect to a vehicle travel direction, each vehicle being driven along a track by respective drive means in at least one of two opposed directions of travel, said equipment comprising:

a light emitter mounted at the rear end of a leading one of said vehicles with respect to the vehicle travel direction and operable to uniformly rearwardly and laterally emit light in predetermined directions;

said light emitter being operable to emit modulated light;

a light receiver mounted at the front end of a trailing one of said vehicles with respect to the vehicle travel direction and operable to receive light emitted uniformly and laterally towards said light receiver by the leading vehicle;

said light receiver being operable to receive incoming modulated light and to generate demodulated output signals;

a drive control for each said drive means of the vehicles; and

said drive control of said trailing vehicle being operable in response to the intensity of said light received by said light receiver on said trailing vehicle and emitted by said light emitter on said leading vehicle, so that the speed of said trailing vehicle is reduced as said intensity of said light received by said light receiver on said trailing vehicle increases;

means for generating a periodic timing signal said light emitter further comprising;

a current source controllable by said periodic timing signal;

a number of infrared emitting diodes power suplied by said current source;

said infrared emitting diodes being arranged in a fan shape configuration substantially in a horizontal plane and being laterally and rearwardly directed at a predetermined emission angle; and

said light receiver further comprising;

at least two infrared sensitive diodes;

said at least two infrared sensitive diodes being arranged substantially in said horizontal plane and being forwardly and laterally directed to cover an angle which is essentially the same as said predetermined emission angle;

an amplifier having an input and an output;

said input being connectable to each one of said infrared sensitive diodes in order to receive a superposed signal; and

a demodulator having an input connected to said output of said amplifier and being connected to said drive control on its output side.

3. The equipment as defined in claim 2, wherein:

said light receiver comprises a first and a second switching device each interconnected between a respective one of said infrared sensitive diodes and said input of said amplifier;

each said first and second switching device being operable by said drive control;

said light emitter forming two groups of said infrared emitting diodes each associated with one side of said light emitter;

said light emitter further comprising a third and a fourth switching device each connected parallel to a respective one of said groups of said infrared emitting diodes; and

said third and fourth switching devices being operable by said drive control.

4. The equipment as defined in claim 2, wherein:

said light receiver further comprises;

a resonant circuit comprising a capacitor and said resonant circuit being connected to said input of said amplifier; and

said infrared sensitive diodes, changing their capacitance and their sensitivity with changing intensity of the ambient light, and being connected parallel to said capacitor.