Abstract: An impact apparatus, e.g. for moving portions (2, 3) of two elements (4, 5) away from each other by a wedge shaped tool (1), which is introducable between said portions, comprises a carrier (9), to which the tool is attached and which is movable relative to a body (10) of the apparatus. An impact member (11) is also movable relative to the body. A movement transmission device (12) acts between the carrier and a device (13) for activating such force influence on the impact member that it is caused to apply an impact on the carrier. The apparatus is so designed that when the carrier (9) is displaced due to actuation of the tool, the movement of the carrier is transferred via the transmission device to the activating device, which causes force influence on the impact member. The activating device (13) may be a valve for pressure fluid supply.