SBB does not claim copyright or a design patent (although to increase their chances they might claim that too). Instead SBB claims that the clock design is their trademark.
This would be similar to Samsung putting the famous bitten apple on Galaxy phones.
And the problem with trademarks is that if you don't defend it, you lose it. It's not like with patents or copyrights were you can ignore infringement or selectively sue companies, depending on how much money you can milk.