GB769804A - Improvements in a device for the determination of reaction time - Google Patents

Abstract

769,804. Determination of physical response time lag. ROYAL SOCIETY FOR THE PREVENTION OF ACCIDENTS. Aug. 5, 1955 [Feb. 3, 1955], No. 3279/55. Class 81(2) In a reaction timing device the testing cycle is initiated by the patient and timing means is started simultaneously with the presentation of a stimulus. The timer is arrested by the patient in response to the stimulus. When electric power is supplied to :the circuit, Fig. 4, closure of switches C and A, by the two hands of the patient, drives a constant speed motor 7, which rotates an arm 10 over a series of contacts 28, 29 and these pass current alternately to green and amber lamps 21, 22. The contacts 30 in the remaining arc are connected to a red lamp 23 and, at the same time as the arm 10 reaches the first of these, a time indicating pointer is connected to the motor. In response to seeing the red lamp the patient releases switch C and depresses switch B and, during the interval between the two actions, the motor is kept running by parallel contacts 19 kept closed automatically over the arc of contacts 30. The motor and time indicator are stopped when B is pressed and lamps 14 are lit, through the lower contact of B, to make the timing indicator visible. A gear driven cam actuates a contact 17 so that when the switches are released the motor runs to a starting position unknown to the patient. The arrangement of the apparatus is shown in Fig. 2. The motor 7 drives a shaft 6 carrying the arm 10 over fixed contacts .9. It also carries a disc 8, having a toothed rack 11 over part of its surface so that, in rotating, it engages a pinion 12, driving a timing disc 24, at the same time that the arm 10 engages the first of the contacts connected to the red lamp. The three coloured lamps 21, 22, 23 are mounted behind a lens 2, so as to be visible to the patient, and the control switches, as C, are arranged at the front of the base. The contacts 19 are actuated by a cam surface 18 on the back of the disc 8 and contacts 17 by a cam 16 driven through reduction gearing 15 from the motor shaft 6.