Locking pin with protected locking mechanism

A locking pin assembly with a protected locking mechanism, comprising:

• an actuator button including a central bore;
• a first guide sleeve attachable to a machine part, the guide sleeve including a central bore and a locking recess;
• a pin connected to the actuator button, the pin axially displaceable and selectively secureable between a locked position and an unlocked position within the central bore of the guide sleeve by actuation of the actuator button, the pin biased by a spring force of a compression spring;
• a locking mechanism disposed within the central bore of the actuator button, comprising:
• a second guide sleeve connected to the first guide sleeve and extending coaxially therefrom, the second guide sleeve disposed in the central bore of the actuator button;
• a locking sleeve secured to the actuator button, the locking sleeve including a sleeve extension having a locking contour with at least one locking lug, the at least one locking lug receivable within the locking recess of the first guide sleeve;
• and
• a detent element located inside the first guide sleeve which interacts with the locking contour of the locking sleeve;
• wherein
• in the locked position of the pin, the locking lugs of the locking sleeve bear on the detent element of the first guide sleeve, and wherein when the locking lugs are rotated by rotating the locking sleeve, the locking lugs pass through the locking recess of the first guide sleeve in an axial direction until the unlocked position of the pin is reached;
• and wherein
• the second guide sleeve extends into the central bore of the actuator button, with an outer circumference of the second guide sleeve slidingly interfacing with an inner circumference of the central bore of the actuator button in both the unlocked state and the locked state of the locking pin such that the locking mechanism is sealed in the central bore of the actuator button in the region of the second guide sleeve.