Patent GB-190813668-A (GB)
Title: Improvements in and relating to Calendar Clocks
Inventor: PARKER JABEZ
Filed: 1908-06-27
Granted: 1909-03-04
Abstract: 13,668. Parker, J. June 27. Calendar work.-The spring that actuates the calendar work is automatically wound each day by the clock, and the entire calendar mechanism may be set by turning a single arbor. A cam 11 driven by the clock-work revolves once in twenty-four hours, winding-up the driving-spring 21 through levers 9, 13, 15, a pawl 28 on the lever 13 engaging a ratchet 20 on the barrel. An arbor 22 to which the other end of the spring is attached drives through gearing 23, 24, 25, a 'month' arbor 27 from which the week, month, and year drums, bands, &c. x, y, z, ara driven. The month arbor is geared to an arbor 39 carrying a locking-disk 38 through wheels and pinions 40, 41, 42, 43, the arbor 39 making thirty-six revolutions for each revolution of the arbor 27, corresponding to the number of tooth spaces in a wheel 45 fast on that arbor and gearing with a seven-toothed pioion 35<a> on a 'week' arbor 44. Once every day, when the engaging roller 10 drops to the lowest part of the cam 11, a spring-controlled catch 30, Fig. 2, mounted with play on the lever 13 depresses one arm of a lever 32 removing the projection 37 from a notch 38<a> in the disk 38. The spring now drives the arbor 27 and changes the date, the wheel 45 and pinion 35<a> rotating the space of one tooth, the teeth of a second pinion 35 on the week arbor 44 then returning the lever 32 into locking engagement with the disk 38 by engaging a hump 36". A spring 34 holds the locking-lever in either position by engaging either of two notches in the arm 36. The varying number of days in the different months is obtained as follows. The wheel 45, Fig. 3, is provided with twenty-seven teeth, an arc 45<a> extending over the space of six teeth and acting as a further tooth, and three teeth 45<b> partly cut away and adapted to be-overlapped by one, two, or three teeth of a concentric disk 46 so as to increase the number of effective teeth from a minimum of twenty-eight to a maximum of thirty-one. The disk 46 is positioned by a roller 57, which is connected to the wheel 45 and disk 46 by a lever 58 and link 60 respectively, and works around a year cam 55, shaped according to the varying length of the months, and a leap year cam 56. These cams are driven from the arbor 27, Fig. 1, by differential gear 63, 64, 65, 66, and 63, 64, 67, 68, respectively, the wheels 64, 65, 67 being solid with one another and loose on the arbor 44. The drum x bearing the days of the week is driven from the week arbor 44 through, gear 48, 49. The days of the month are carried by two drums y, y<1>, the latter bearing the units and being driven from the arbor 27 through gearing 72, 73, 74,75. The tens drum y has the figures 1, 2, 3 repeated twice and a blank space; and is driven from the arbor 27 through gear 77, 78, 79, 80, the gear 77 having preferably four teeth and four plain arcs each acting as a tooth, and the pinion 78 eight teeth. The year drum z is driven from the arbor 27 through gear 82, 83, 84. Two methods are described of locking the pinion 35<a> on the week arbor 44 while the month wheel 45 is slipping the requisite number of tooth-spaces at the end of the month. In the arrangement shown in Fig. 3, the arc 45<a> having a radius equal to thit of the pitch circle, the addenda of two teeth of the pinion 35<a> rest against it locking the pinion but permitting the arc to slip under them. In the form shown in. Fig. 8 a cam 69 revolving with the wheel 70 holds a leverp in locking engagement with the pinion 73 while the plain arc is passing, the radius of the arc in this case being less than that of the pitch circle. To set the calendar, a lever 26 which carries the wheel 24 is raised so as to disconnect the arbor 39 from the driving spring 21, and the arbor, having been pressed back to disengage the disk 38, may be rotated by a key. The number of teeth in the various wheels and pinions is stated.