GB1083940A - Tachometer - Google Patents

Abstract

1,083,940. Speedometers. R. R. PASINSKI and J.R. ENGLAND. Dec. 29, 1965, No. 55104/65. Headings G1J and G1K. A vehicle driven by an I. C. engine is provided with a lamp (132) to indicate the attainment of the rotative speeds at which gear changes in the transmission (144) should be made. For each gear setting a photo-cell (62) (64) 60 is provided in series with a normally open switch (138) (140) (142) which is actuated to close only in that gear setting. In any of the gear settings, when a particular speed associated therewith is sensed by a tachometer 14 and indicated by the angular displacement of a shaft 18, a light shield 20 (with openings (30) (34) (32) in positions associated with the particular speeds) carried by the shaft 18 triggers the corresponding photo-cell. To initiate and maintain energization of the lamp until the gear setting is changed, a solid state controlled rectifier (164) has the photo-cells (62) (64) 60 arranged in its gate-cathode circuit in parallel with a set of contacts (138a), (140a), (142a) of the respective switches and the lamp (132) in its anode-cathode circuit which also includes the vehicle battery (168), ignition switch (172) and, in parallel, another set of contacts (138b) (140b) (142b) of the switches. Particular values. Angular adjustment of a photo-cell e. g. 60 about the axis of shaft 18 to predetermine the speed at which it triggers the rectifier to energize the lamp is made by turning a cranked arm 110 by means of a slotted head 108 to engage a lead 66 of the photo-cell and pivot it on a bushing 70 relative to the opening (32) in the shield 20. The other lead 68 brushes a flange 80 of a contact sector 82 connected to a cable 92 by a strip 90 integral with a retaining tab 44. Zero adjustment of the tachometer 14 is effected by a slotted head 120 on a shaft 118 carrying a cam 122 extending into a pivoted fork 124 connected to the shaft 18.