Gear unit with a lag function

A gear unit having:

• a drive element with a first tooth structure,
• an output element with a second tooth structure,
• wherein the tooth structures are able to be brought in engagement cogging with each other to form a gearing in at least one engagement area of the second tooth structure,
• wherein the output element has at least one uncoupling area,
• in which the cogging engagement of the gearing is uncoupled,
• wherein the first tooth structure has at least one first modified tooth element and
• wherein the second tooth structure has at least one second modified tooth element,
• wherein by a movement of the drive element, synchronization of the second modified tooth element with the first modified tooth element is enabled in order to create a change from the uncoupled state to the engagement state,
• wherein the second tooth structure has at least one lengthened tooth element with an enlarged length, which is greater than a smaller length of the rest of the second tooth structure,
• wherein the first modified tooth element of the first tooth structure has an enlarged length, that is greater than a smaller length of the majority of the first tooth structure, and
• a blocking element whereby the output element is blocked in the uncoupled state and the gear unit is configured to be self-locking,
• wherein the blocking element further includes a blocking surface and the blocking element is disposed adjacent the first tooth structure and arranged on the drive element.