Patent GB-952233-A (GB)
Title: Improvements in or relating to timing devices
IPC: G04F8/00
Filed: 1961-11-07
Abstract: 952,233. Testing reaction times. G. REDMAYNE. Nov. 7, 1962 [Nov. 7, 1961], No. 39871/61. Heading A5K. [Also in Division G3] The time taken for a person to react to a stimulus is tested by a device comprising a number of independently movable indicating members 15 which are releasable from pre-set positions for movement each under a loading force, operator-controlled means for releasing a first one of these members, the members being coupled together with lost motion so that release of the first member causes the release at successive intervals of the remaining members, and operator-controlled means for arresting movement of the device whereby an elapsed time can be measured. The indicating members 15 comprise four discs which are freely mounted on a horizontal spindle 14 with spacers 18 between them and are weighted by weights 36. A cranked rod 29a, 29, 30, 31 is fixed at its end 29a to the spindle 14 and has two longitudinally extending portions 30, 31 passing respectively through an arcuate slot 28 in the first disc and through similar slots in the remaining disc. Rotation of the spindle 14 by a control knob 27 moves the discs, through the cranked rod, to a set position where the weight 36 of the first disc is over one side of a top dead-centre position and the disc can rotate under the weight upon de-energization of a holding solenoid E which retains an armature 34 fixed to the disc. The remaining discs are simultaneously rotated to a set position where their weights 36 are on the other side of the dead-centre position so holding them by gravity against the portion 31 of the cranked rod, this rod being returned to the position shown where the radial portion 29a engages an adjustable stop 33. The spindle 14 at the end nearest the control knob 27 is resilient, and to start a test is rotated torsionally through the knob by the operator supervising the test until a cam 41 operates a microswitch G which may light a signal lamp and which breaks a circuit of the holding solenoid E to release the first disc. The remaining discs are automatically released in succession over their dead-centre positions for rotation under gravity, by a projection 38 on each disc engaging a cooperating projection 37 on the next succeeding disc. On receiving a starting signal, the test subject reacts by operating a switch in the circuit of a second holding solenoid A which is de-energized to release a braking armature 24 movable longitudinally under a spring 23 to compress the discs 15 and spacers 18 thereby arresting movement of the device. The discs are graduated circumferentially in milli-seconds and the reaction time is read against fixed pointers 9. The switch G and solenoids A and E are shown in a circuit, Fig. 2, arranged to demonstrate how quickly a motorist in response to a visual stimulus can operate his accelerator and brake controls. This circuit includes a switch D under the control of the supervisors switch G through solenoid E to operate a buzzer C and switch on a light (not shown). Switches K and L controlled by the test subject and representing the accelerator and brake pedals, are in circuit with the solenoid A. Additional switches H and I are provided for bringing into the circuit either a battery J or a source of power provided by the output H of a transformer. Variable resistors B and F are also incorporated.