Timepiece pallet fork for mechanical oscillator and timepiece time-delay release mechanism

A timepiece pallet fork for a mechanical oscillator, comprising:

• an arbor having a pivot axis, the timepiece pallet fork configured to oscillate about the pivot axis;
• and
• first and second pallets configured to alternatively engage with an escapement wheel when the timepiece pallet fork oscillates about the pivot axis, the first pallet being displaceable with respect to the arbor by absorption of energy from a first upstream waiting position to a first downstream stopping end position which is offset compared to the first upstream waiting position, a downstream direction being a direction of progression of a tooth of the escapement wheel before a stopping of the tooth by the first pallet;
• and
• a first arm having an intermediate section including an elastic bend shaped as a strip having a width direction which is substantially parallel to the pivot axis, one end of the arm being fixed with respect to the arbor to form a first fixed end, the intermediate section of the first arm being located between the first fixed end and the first pallet and returning the first pallet towards the first upstream waiting position by the intermediate section being elastically deformable from a first configuration, in which the first pallet is in the first upstream waiting position, into a second configuration, in which the first pallet is in the first downstream stopping end position further comprising:
• a stop configured to stop the first arm downstream, with respect to the arbor, as soon as the first pallet is in the first downstream stopping end position, wherein the stop is formed by the arbor.