Patent GB-411910-A (GB)
Title: Mechanical calendar
IPC: G04B19/253
Filed: 1932-12-16
Abstract: 411,910. Date-indicators; clocks. AKTIEBOLAGET SPARURET, 9, Kungsgatan, Stockholm. Dec. 16, 1932, Nos. 35689 and 35690. Convention dates, Dec. 22, 1931 and April 23, 1932. [Class 106 (iv).] A mechanical date-indicator comprises coaxial day-name, date-number, month and year indicating members, the date-number member being restored to its initial position by spring means controlled by a member positioned by cams on the month and year members or by pins on the month member, the cams or pins being situated at distances from the common axis corresponding to the numbers of days in the different months, provision being made to effect an automatic correction in leap-years. In the embodiment shown in Figs. 1, 2, 4 and 10, the date indicator 11 is actuated by a link 5 which, at midnight, falls over the point of a snail cam 6 driven through a 1 : 2 gearing from the hour hand of a clock. The snail cam can be rotated to adjust the date indicator independently of the clock. The lower end of the link 5 is connected to an arm pivoted about the centre of the date indicator and carrying a pawl 33, Fig. 10, spring-pressed into engagement with teeth on the day-name ring 17, Fig. 2, and on the date-number ring 18. During the first part of its stroke, the pawl 33 engages both rings 17, 18 but when the date-number ring 18 has been advanced one step, a cam surface 25 causes the pawl to complete its stroke in engagement with the day-name ring 17 only. During its clockwise movement the ring 18 winds up a spring 28 and is normally detained by a pawl 53. At the end of a month a pin 12 on the datenumber ring 18 engages a lever 24 pivoted to a plate 66, a spring 70 then slipping over a cam 68 on the plate 66 and rotating the plate into the dotted position, Fig. 10. The plate 66 has a rim 69 which lifts the pawl 53 and allows the spring 28 to turn the ring 18 anticlockwise into its initial position. The pin 12 abuts against the back 58 of the lever 24 and resets the plate 66, a pin 72 defining the normal position. A notch 60 on the lever 24 engages one of a series of pins M1-M12 on the month ring 19, and on the clockwise movement of the plate 66 the notch engages the next pin (e.g., M2) so that on the restoration of the plate the month ring is moved one step. The pins M1-M12 are each spaced from the centre of the ring 19 a distance in accordance with the number of days in the months to which they correspond, and consequently the lever 24 may occupy one of four positions, depending upon which month pin is engaging the notch 60. The pin 12 thus engages one of four steps D28, D29, D30 or D31 in the lever 24 and initiates the restoration of the date-number ring 18 after 28, 29, 30 or 31 days. The " February " pin M2 is mounted on a member 47, Fig. 4, slidable radially in the month ring and having a second pin 45 spring- pressed against a cam 29 on the year disc 20 and so arranged that the pin M2 occupies a "29-day " position at the end of January in a leap year. The year disc 20 is detained by a pawl 39 which at the end of a year is lifted by a cam 59 on the month ring, so that the pin 45 is then able to step the year disc forward as the month ring is moved. In a second embodiment, Figs. 14 and 15, the date indicator may be driven either by hand or from a clock. A lever 56 pivoted about the centre 61 carries a pawl 35 engaging the day-name ring 17<1> and the date-number ring 18<1> as previously described. A member 125 may be moved to form a continuation of the cam surface 251 so that the ring 17<1> may be moved independently of the ring 18<1> for adjusting purposes. As the date-number ring 18<1> rotates a snail cam 49 secured to it raises an arm 63 by bearing on pins 80, 150 secured to the arm. The arm 63 is pivoted at 261 and as it rises it tensions a spring 89. When the pin 80 slips over the end of the cam 49 this spring retracts the arm and drives a pinion 87 through a rack 83 secured to the arm. A pinion 86 connected to the pinion 87 engages a rack 95 secured to the rear of the date-number ring 18<1> to turn this ring forward to its initial position, the month ring 19<1> being advanced by a pawl 82 on the arm 63. The pin 80 is secured to a carriage 64 slidable along the arm 63 into four positions in accordance with the different numbers of days in the months, the position being determined by a lever 73 controlled by a cam 57 connected to the month ring 19'. At the " February " position the cam 57 is cut away and the roller 74 on the lever 73 passes through to engage a second cam 291 connected to the year disc 20<1>. At leap year, a lobe of the cam 291 so controls the members 74, 73, 64 that the disc 18<1> is turned to its initial position after the passage of twenty-nine days. The year disc 20<1> is actuated by a pin 99 connected with the month disc and engaging a pinion 90 gearing with a pinion 100 on the shaft 61 carrying the year disc. The month ring may be adjusted by swinging anticlockwise an arm 127 having a finger 146 engaging the feeding teeth 62 of the month ring. A cam 129 on the arm 127 simultaneously disengages the rack 83 and moves from the teeth 62 a pin 144 which engages them in the bottom position of the arm. The year disc is adjusted by a lever 133 carrying a pawl which comes into engagement with a ratchet wheel 140 on the year-disc shaft 61. The Specification as open to inspection under Sect. 91 describes also a further modification, in which the spring 89 is replaced by a spiral spring enclosed in a toothed barrel gearing with a second set of teeth on the upper edge of the rack 83, the even action of the device being ensured by an air brake. Other forms of clock-controlled driving mechanism are also described. One of these is shown in Figs. 20 (Cancelled) and 23 (Cancelled). The clock spring 214 is connected at its outer end to a toothed barrel 217 gearing with the hour spindle and at its inner end to a winding shaft 181 normally prevented from reverse rotation by a pawl mounted on a wheel 220 gearing with a wheel 210 fixed to a shaft 190. The shaft 190 also has secured to it a crank disc 174 carrying a pin 173 which reciprocates the link 170 driving the date-indicator. A wheel 175 freely mounted on the shaft 190 is driven to make one rotation in twenty-four hours and at midnight a recess in the wheel comes opposite a knob 203 on a spring 200 which spring then moves so that its end 201, Fig. 20 (Cancelled), is clear of the last of a train of wheels geared to a wheel 191 on the shaft 190. This shaft is then rotated by the spring 214 through the shaft 181, locking pawl and wheels 220, 210, the link 170 actuating the date-indicator. At the end of one rotation of the disc 174 a pin 205 thereon moves a sliding piece 204 in the wheel 175 to return the spring 200 into its normal position where it stops the motion of the shaft 190. In a modification, Fig. 25 (Cancelled), the disc 174, driven as previously described, carries a tooth 245 upon which a lever 246 normally rests. The wheel 175, free on the shaft 190, has secured to it a pin 251 which at midnight lifts the lever 246 through a projection 250. A wheel 254, geared to the shaft 190, carries a pin 258 which normally abuts against the lever 246. When the lever is lifted it clears the pin 258 and also a second pin 259 and the wheel 254, shaft 190 and disc 174 commence to rotate. The tooth 245 moves from beneath the lever 246 which is then lowered below the pin 258 until the disc 174 has completed one revolution, when the lever is raised by the tooth and obstructs the pin 258 to stop the shaft 190. The clock may be provided with a hand which rotates once in twenty-four hours or with a disc, also rotated once in twenty-four hours, divided diametrically into two portions of different colours. When the clock is indicating a.m., one colour is seen through a window, the other being visible when it is indicating p.m. In a further modification, the disc has eight sectors of alternate different colours and is moved one-eighth of a rotation every twelve hours by a pin on the wheel 175. This subject-matter does not appear in the Specification as accepted.