Threaded plug and screwdriver device

Abstract

A device comprises a threaded plug ( 1 ) and related screwdriver ( 10 ). The plug ( 1 ) has a single-piece structure, with a longitudinal axis ( 2 ) of symmetry, a head ( 5 ), a body ( 3 ) with an outer thread ( 6 ) and a tightening flange ( 4 ) interposed between the head ( 5 ) and the body ( 3 ). The head ( 5 ) is shaped as a tubular solid ( 8 ) projecting from the flange ( 4 ) in a direction parallel with the axis ( 2 ), and comprises an inner cavity ( 7 ), laterally surrounded by a non-circular surface ( 22 ) of an annular wall ( 9 ). The non-circular surface ( 22 ) is oblique and diverges from the axis ( 2 ) travelling from the body ( 3 ) to the head ( 1 ). The screwdriver ( 10 ) comprises a shaped head ( 12 ) equipped with surfaces ( 13 ) which can be coupled with the non-circular surface ( 22 ) with direct contact and automatic taking up of the coupling play.

1 ) Device comprising a threaded plug ( 1 ) and related screwdriver ( 10 ), in which the plug ( 1 ) comprises a single-piece structure having a longitudinal axis ( 2 ) of symmetry, and comprising a head ( 5 ), a body ( 3 ) with an outer thread ( 6 ), and a tightening flange ( 4 ) interposed between the head ( 5 ) and the body ( 3 ); the structure in which the head ( 5 ) has the shape of a tubular solid ( 8 ) projecting from the flange ( 4 ) in a direction parallel with the axis ( 2 ) of the plug ( 1 ), and comprising an inner cavity ( 7 ), accessible from the outside through one end of the solid ( 8 ), the cavity ( 7 ) being laterally surrounded by a non-circular surface ( 22 ) of an annular wall ( 9 ) which is oblique relative to the axis ( 2 ) of the cavity ( 7 ) and diverging from the axis ( 2 ) along a direction of travel from the body ( 3 ) to the head ( 5 ) of the plug ( 1 ), the screwdriver ( 10 ) comprising a shaped head ( 12 ) equipped with surfaces ( 13 ) which can be coupled at least with the oblique surface ( 22 ) with direct contact and automatic taking up of the coupling play, the device ( 1 ,  10 ) being characterised in that the head ( 12 ) of the screwdriver ( 10 ) comprises a cap-shaped structure ( 18 ) equipped with shaped perimetric edges ( 15 ), at least at a pair of walls of the head ( 12 ) matching inner projections ( 16 ) of the cavity ( 7 ). 
     
     
         2 ) The device according to  claim 1 , characterised in that the surfaces ( 13 ) of the screwdriver ( 10 ) and the surface ( 22 ) of the wall ( 9 ) can be coupled with mating contact. 
     
     
         3 ) The device according to  claim 1  or  2 , characterised in that the head ( 12 ) of the screwdriver ( 10 ) basically has the shape of a truncated pyramid, shaped to match the shape of the cavity ( 7 ). 
     
     
         4 ) The device according to  claim 1  or  2  or  3 , characterised in that the screwdriver ( 10 ) comprises a bar ( 14 ) which is fixed to the head ( 12 ) and in an axial position. 
     
     
         5 ) The device according to  claim 4 , characterised in that the head ( 12 ) and the bar ( 14 ) are made together in a single body. 
     
     
         6 ) The device according to  claim 1 , characterised in that the shaped perimetric edges ( 15 ) of the cap ( 18 ) comprise indentations ( 23 ) shaped to match the inner projections ( 16 ) of the cavity ( 7 ). 
     
     
         7 ) The device according to  claim 1  or  6 , characterised in that the screwdriver ( 10 ) comprises a plurality of concentric caps ( 18 ), which can be selectively used for screwing in plugs ( 1 ) of different sizes using a single screwdriver ( 10 ). 
     
     
         8 ) The device according to any of the foregoing claims, characterised in that the screwdriver ( 10 ) is made of plastic material. 
     
     
         9 ) The device according to the foregoing claims, characterised in that the body ( 3 ) of the plug ( 1 ) comprises a smooth cylindrical collar ( 17   b ) preceding the start of the outer thread ( 6 ) of the body ( 3 ).