GB880615A - Improvements in or relating to electric lamp and like fittings - Google Patents

Abstract

880,615. Brackets. IGRANIC ELECTRIC CO. Ltd. Feb. 11, 1959, No. 4759/59. Class 52(5) [Also in Group XXV] In a fitting of the type in which an electric lamp or other device is supported by means of a pivoted arm, a C-shaped spring is incorporated in the pivot joint to resist but not prevent pivotal movement. Preferably friction means are also included in the pivot. The device 1 is supported by an arm formed in two pivotally connected parts 3, 5 joined to a swivelling base plate 7 by a pivot according to the invention. The base plate 7 carries a U-shaped member 10 having arms 11 formed with pinion teeth 12, and a similar member 13 having arms 14 is secured to the lower lamp-carrying arm 5. Pivot pins 16, 17, journalled in the arms 11, 14 respectively, are held a constant distance apart, so that the teeth are in mesh, by means of a pair of plates 18, 19 threaded on to the pins and separated by spacers 20, 21. Bushes 22, 23, are threaded on to the pins on each side of the joint, which is symmetrical, and over the bushes are threaded a friction plate 24, spring washers 25, 26, and a plate 27 formed with bosses 28, 29 extending beyond the bushes. The friction of the joint is adjusted by a nut 30, screw threaded on to the pin 17 to abut the boss 28, and a nut 31 screw threaded on to the pin 16 to abut a shoulder inside the boss 29. The boss 29 has two radial projections 33 located, when the joint is assembled, on either side of a stop 34 on the base plate 7, and a C-shaped laminated spring 9 is passed over the boss so that its ends engage the opposite sides of the projections and the stop. When the arm 5 is inclined in either direction from the vertical the plates 27 on each side of the joint, together with their bosses 29, turn through half the angle in the same direction, and the projections 33 are moved out of alignment with the stops 34 to stress the springs. A cover 35 is provided on each side of the joint. The spring may act throughout the whole movement of the arm, or a lost-motion may be provided between the spring and the projections and stop so that the spring is inoperative over a range of positions of the arm.