GB1372273A - Adjustable-programme time switch - Google Patents

Abstract

1372273 Time switches DANFOSS AS 11 Nov 1971 [16 Nov 1970] 52422/71 Heading H1N An adjustable-programme time switch having a rotating timing disc has a readily removable programme disc fitted on the rear of the timing disc for rotation therewith wherein the annular zone adjacent the circumference of the programme disc can be readily provided with gaps extending from the circumference by removal of portions of the programme disc such that contacts are controlled in dependence upon the said gaps. As shown, a timing mechanism 3 has a gear 4 coupled (Fig. 3, not shown) to a gear 12 which drives a backing disc 14 via a one-way slipping clutch spring 13. Disc 14 is carried on a journal 5 fixed to base frame 1 and has a hub 16 on which a programme disc 17 and a time disc 18 are secured by a nut 19. A pin 20 ensures angular correlation of discs 14, 17, and 18. Disc 18 comprises a metal disc 22 and a transparent disc 23, one of which carries the time scale 36. Nut 19 permits removal of disc 18 for alteration of programme disc 17, which is made of a material such as polystyrene which can be readily cut for removal of portions of its outer annular zone to provide gaps 33 which enable contacts 10 and 11 to engage the metal disc 22. Disc 17 is of smaller radius than disc 22 such that a contact 9 is in continuous engagement with the disc 22. The contacts 10 and 11 may be offset circumferentially (Fig. 4, not shown) to make and break a circuit via contact 9 at different times, or the programme disc 17 may be cut away for different angular extents (35) at the corresponding radii. The metal disc 22 provides an annular window 38, with only thin webs 39 holding the outer portion, and the gaps 33 can be seen therethrough. The front face of disc 14 is contrastingly coloured, e.g., black, and is visible through the opening 38 and gaps 33. The programme disc 17 is provided with time scales (28, 29, Fig. 4, not shown) in hours and days of the week, corresponding to the scales 36, and has radial lines at hourly spacing to assist in creating gaps of the desired length; it is of reduced thickness along a circular line (30) such that a portion may be easily broken off after making two radial cuts.