# US 4,381,555 A · Apparatus for measuring the braking time of a motor vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,381,555 A - Document ID: US4381555A - Status: Granted - Kind: A - Application number: 06/138,746 - Filed: 1980-04-09 - Granted: 1983-04-26 - Earliest claimed: 1979-04-10 - Assignees: Audi NSU Auto Union Aktiengesellschaft - Inventors: Karl-W. Heinle - Web page: https://patentgrep.com/patent/US4381555A ## CPC - G01P 1/10: for indicating predetermined speeds - G01P 15/0891: {with indication of predetermined acceleration values (G01P15/135 takes precedence)} - G07C 5/085: {using electronic data carriers} - G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G}) - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE ## Abstract Apparatus is described for recording certain operating conditions of a motor vehicle, those conditions occurring upon the braking of the vehicle, and the apparatus is particularly applicable to vehicles equipped with antilock braking systems. A shift register is controlled by an oscillator in continuously shifting operation. When a predetermined driving condition occurs, the state of the first register location is changed. In the event the device is used for recording a braking condition, there is provided a time delay switch which locks the shift register at the point it has reached when a predetermined delay time is exceeded. The aforementioned shift register can be constructed in the form of an electromechanical shift register which responds to a signal generated through the operation of a stop lamp switch. ## Claims ### Claim 1 Apparatus for measuring the time elapsed between application of a vehicle brake and occurrence of a predetermined event, comprising: a shift register having a number of register locations, each of which is capable of assuming one of two binary states and having a means for receiving shift pulses which cause the contents of a given register location to shift to the next succeeding register location upon application of each shift pulse, oscillator means for supplying shift pulses to said means for receiving shift pulses in said shift register, brake signal generator means connected to a signal input of said shift register for changing the binary state of a first location in said shift register upon application of the vehicle brake, switch means operable responsive to a predetermined acceleration value experienced by said vehicle to disconnect said oscillator means from said means for receiving shift pulses, and interrogation terminal means for determining the number of locations in said shift register containing bits of changed binary state for providing a measure of time elapsed between application of the vehicle brake and occurrence of the predetermined event. ### Claim 2 (depends on 1) The apparatus defined in claim 1 wherein said shift register is an electronic digital shift register in which the different states of each register location are zero and one states. ### Claim 3 (depends on 2) The apparatus defined in claim 2 further comprising a reserve power source for maintaining the contents of said shift register. ### Claim 4 (depends on 1) The apparatus defined in claim 1 wherein said shift register is an electromechanical shift register. ### Claim 5 (depends on 4) The apparatus defined in claim 4 wherein said electromechanical shift register comprises a rotatable disc divided into a plurality of sectors, each said sector being movable from one plane to another, synchronous motor means for driving said rotatable disc, oscillator means for operating said synchronous motor means, switch means operable responsive to a given acceleration value for disconnecting said oscillator means from a source of power and means for moving said sectors from one plane to another operable responsive to said brake signal generator. ### Claim 6 (depends on 5) The apparatus defined in claim 5 wherein said disc sectors are made of a magnetizable material and wherein said means for moving is an electromagnet. ### Claim 7 (depends on 6) The apparatus defined in claim 6 wherein said brake signal generator means is a stoplight switch. ### Claim 8 A method for measuring elapsed time between application of a vehicle brake and occurrence of a predetermined event, comprising the steps of: supplying shift pulses to a shift register causing each individual bit to shift from its current register location to the next succeeding location in said shift register, interrupting the flow of shift pulses to said shift register upon occurrence of said predetermined event, changing the binary state of a first location in said shift register upon application of the vehicle brake and continuing to change the state of that location in said shift register so long as said vehicle brake is actuated, and interrogating said shift register to determine the number of locations containing a bit of changed binary state to provide an indication of the elapsed time between brake application and the predetermined event.