GB701454A - Improvements in or relating to an electrically driven windscreen wiper - Google Patents

Abstract

701,454. Spring applied brakes. SWF-SPEZIALFABRIK FœR AUTOZUBEHÍR G. RAU GES. April 18, 1951 [Oct. 18, 1950], No. 9113/51. Class 103(1) [Also in Groups XXIII and XXXVII] Relates to brake mechanism for an electricallydriven windscreen wiper (see Group XXIII). A brake drum 43 is provided on the armature of the wiper motor and is engageable by a brake 18 on a two-armed lever 32, 33, Fig. 2, secured to a shaft 29 rotatably mounted in a housing 24. The end of the lever 33 is provided with the contact 6. Also secured to the shaft 29 is a bell-crank lever 34, 35 the end of the arm 34 being provided with a nose 28 engageable in a notch 26 in a cam 25 secured to a driven shaft 22, whilst the end of the lever 35 is connected to a cable 30. The brake is urged towards the drum and the contacts 5, 6 (5 being fixed), are opened by means of a spring 36 surrounding the shaft 29 and anchored at its ends to the housing 24 and the lever 34, 35. When the brake is operative the nose 28 is engaged in the notch 26 and the blades are in a parked position. By pulling the cable 30 and securing it in its pulled position by means not shown the nose is removed from the notch, the brake is released and the contacts 5, 6 are closed so that the motor is energized and then operates the wipers. To stop the wipers the cable is released and the spring 36 then tends to urge the brake towards the drum and to open the contacts. However the motor continues to operate with the nose 28 riding over the periphery of the cam 25 until the nose enters the notch. The contacts 5, 6 then open and the brake is positively applied by the spring to instantly arrest the motion of the armature. In another embodiment the two armed lever 34, 35 is operated by an electric solenoid. To stop the wipers the solenoid is deenergized and the mechanism then operates as previously described. A band type brake may be used instead of the block type shown.