GB111785A - Improvements in or connected with Speed Indicators. - Google Patents

Abstract

111,785. Chadburn, W., and Chadburn, W. R. Jan. 3, 1916. Periodic - counter speed indicators comprise cams 21, 22, 23 upon a constant-speed shaft 20 controlling respectively the following parts :-(1) the link-work 62, 63<a>, 64 which effects the periodic engagement, between two wheels 6, 55 with wedgeshaped edges of a V-edged jockey or coupling wheel 61, thereby producing an intermittent rotation of the intermediate wheel 55 from the speeddriven shaft 5; (2) a lever 66 and co-operating V- edged friction pawl 65, which is released, so as to hold the intermediate wheel against a spring return, immediately before termination of the driving period; (3) a similar lever and detent for holding a wedge-shaped edge wheel 56 except for a brief interval following termination of the driving-period. This wheel carries the speed pointer 1 and has a definite zero position defined by a stop, to which it is urged continually by a spring 70, and during the release it moves into agreement with the intermediate wheel, if not already in that condition, as determined by one-way driving- pins 59, 60. At other times, the wheel and pointer remain at the last speed indication. Spring restoration and stop parts are provided for the intermediate wheel 55, which thus always starts from a zero position. The arrangement may be modified by the employment of a second pointer actuated at a recognized time-interval, such as one minute, or two such pointers may be provided, the one to remain at the speed last measured while the other is reset to zero and makes a new measurement. Specifications 1421/74, 7385/03, 4189/04, 16320/04, 21467/07, [Class 37, Electricity, Measuring &c.], 23249/07, 27237/09, and 22980/11 are referred to.