The second friction surface is located between a plate spring (6) and a support disk (7).

The plate spring (6) is connected to the damper cage (4) while the support disk (7) is connected to the hub (1).

The stop plate (12) is provided with a plurality of holes which are meshed with the plurality of protrusions on the stop disc (11).

A stop disc (11) is provided on the lower portion of the main shaft (19).

In fifteen seconds I should reach the bottom plate.

The invention concerns a part forming a contact stop against the moulding consisting of a stop disc (12) mounted freely rotating at the tip of a tilting rod (11) operated with a lever (5).

The integral compliant foil thrust disk (16) may in the alternative or in addition, include a plurality of radially outwardly extending tabs (36) to locally increase the flexural rigidity of the disk (16).

A plurality of circumferentially equispaced protrusions are provided on the lower end of the stop disc (11).

A stop disc (32) carried on the stem pin limits the fall of the rod in the tube when the orbiting stops.

A bearing plate (19) is introduced into each opening (20) with a central drilling (30) in which a pin end (28) of a bearing pin (27) for a pinion gear (14) is retained.

The stop disc (62) contacts a face of the cylindrical section (72) and has a lead-through opening (63) for the drilling needle (1).

Into the clamping screw (31) is screwed a threaded rod (48), the end of which is fitted with a stop disc (52) for the workpiece to be machined.

The inventive well drilling device comprises a core barrel provided with an adapter, a spindle rod which is arranged inside the core barrel and provided with a drill and a bearing disk.