The invention relates to a tipping actuator for a conveyor system that comprises a plurality of article carriers moving on an endless conveyor in a conveying direction, each article carrier having a carrier frame for bearing an article, the carrier frame being pivotally mounted on the article carrier and operable to tip to enable discharge of the article borne on the carrier frame. The tipping actuator comprises a trigger member for contacting the article carriers to tip them and is configured such that, when in a non-contact position, the article carriers are able to at least partly tip towards the trigger member such that the contact portion of the trigger member is received by a portion of the article carrier. In another embodiment, a contact portion of the trigger is sloped with two different gradients. An electromagnet may be used to cause actuation of the trigger. The tipping actuator may be able to allow tipping in opposite directions of adjacent carriers, for example in some embodiments the trigger may be formed of upstream and downstream parts.