Teat cup shell teat cup and arrangement for automatically milking animals

A teat cup shell (2) adapted to form at least a part of an outer limiting portion of a teat cup and being adapted to be held by an electromagnetic device, the teat cup shell (2) comprising:

• a tubular body (5) having a center axis (4),
• wherein the tubular body (5) comprises an outer circumferential magnetic layer comprised of a magnetic material,
• wherein a plane (6) extending along the center axis (4) defines a first shell portion (8) and a second shell portion (10) on opposite sides of the plane (6),
• wherein the first shell portion (8) comprises a first part of the outer circumferential magnetic layer,
• wherein the second shell portion (10) comprises a second part of the outer circumferential magnetic layer,
• wherein the first part of the outer circumferential magnetic layer defines an outer surface (12) adapted to, when engaging with the electromagnetic device, abut against at least one surface of the electromagnetic device with the electromagnetic device magnetically holding the tubular body (5) along an exterior surface of the first part of the outer circumferential magnetic layer magnetic material,
• wherein the first shell portion (8) and the second shell portion (10) differ from each other with respect to at least material thickness, such that at least a portion of a thickness of the first part of the outer circumferential magnetic layer is higher than a greatest thickness of the second part of the outer circumferential magnetic layer, and an amount of the magnetic material in the first shell portion (8) is higher than in the second shell portion (10), and
• wherein the outer circumferential magnetic layer has a circular outer cross section and a circular inner cross section when seen along the center axis (4), with the circular inner cross section being offset in relation to the circular outer cross section.