Tool for separating a back from a middle of a timepiece, as well as a back having a slot adapted to receive the tool, and timepiece equipped with such a back

A timepiece and tool intended to be used by a horologist to separate a back from a middle, which jointly delimit a watch case of said timepiece, inside which a horological movement is housed, said tool having the appearance of a wedge, i.e. an acute-shaped part formed by a first face and a second face which intersect at an angle of less than 90° and which are connected to one another by a rounded portion, the first face of the tool being arranged such that it extends parallel to a mean plane wherein the horological movement is located when the horologist engages said tool between the back and the middle in order to separate said back from said middle, the rounded portion being connected to the second face by a curved portion, the curvature whereof is directed towards the inside of a surface delimited by the first and second faces, the back of the timepiece being delimited externally by a perimeter, at at least one point whereof a slot is provided which frees, between said back and the middle, a space allowing the horologist to engage the end of the tool by means whereof the horologist will exert leverage on the back in order to separate said back from the middle, said slot comprising a first planar surface parallel to the mean plane wherein the horological movement extends, said first planar surface being extended by a second inclined planar surface which forms, with the mean plane, an acute angle when the back is fixed to the middle, said second inclined planar surface extending away from the middle towards the bottom thereof, the angle between the first face and the second face of the tool being less than the acute angle formed by the second inclined surface with the mean plane.