Fastening system

Abstract

A fastening system with a screw which comprises a screw head and on a screw shank a thread which with respect to the pitch and the flank angle is matched to the formation of a thread in a bore of a plastic material, and at least one axially extending deepening on the thread root, and with a plastic material with a bore into which the screw may be threaded whilst forming a thread and/or with a clip with two clip bows and a clip back which connects these and which comprises a through bore traversing the clip bows, with a thread for rotating in the screw and at least one resilient lug aligned radially to the axis of the through bore, for latching into the at least one deepening of the screw when this is rotated into the through-bore of the clip.

1 . A fastening system with 
 a screw ( 1 ) which comprises a screw head ( 2 ) and on a screw shank ( 3 ) a thread ( 4 ) which with respect to the pitch (h) and the flank angle (α) is matched to the formation of a thread in a bore ( 9 ) of a plastic material ( 7 ), and at least one axially extending deepening ( 5 ) on the thread root, and    with a plastic material ( 7 ) with a bore ( 9 ) into which the screw ( 1 ) may be threaded whilst forming a thread and/or    with a clip ( 17 ) with two clip bows ( 18 ,  19 ) and a clip back ( 20 ) which connects these and which comprises a through bore ( 23 ′,  23 ″) traversing the clip bows ( 18 ,  19 ), with a thread ( 24 ) for rotating in the screw ( 1 ) and at least one resilient lug ( 25 ) aligned radially to the axis of the through bore ( 23 ′,  23 ″), for latching into the at least one deepening ( 5 ) of the screw ( 1 ) when this is rotated into the through-bore ( 23 ′,  23 ″) of the clip ( 17 ).    
     
     
         2 . A fastening system according to  claim 1 , in which the thread ( 4 ) of the screw ( 1 ) has a flank angle of (α) of about 20 to 40°, in particular of about 30°.  
     
     
         3 . A fastening system according to  claim 1  or  2 , in which the thread ( 4 ) of the screw ( 1 ) has a pitch (h) of about 1.5 to 3.5 mm, in particular of about 2.2 mm.  
     
     
         4 . A fastening system according to one of the  claims 1  to  3 , in which the screw ( 1 ) comprises several deepenings ( 5 ) on the thread root arranged uniformly distributed over the circumference of the screw.  
     
     
         5 . A fastening system according to one of the  claims 1  to  4 , in which the at least one deepening ( 5 ) is aligned parallel to the screw shank ( 3 ).  
     
     
         6 . A fastening system according to one of the  claims 1  to  5 , in which the at least one deepening ( 5 ) has a symmetrical cross sectional shape.  
     
     
         7 . A fastening system according to one of the  claims 1  to  6 , in which the at least one deepening ( 5 ) has an asymmetrical cross sectional shape, which is designed such that the screw ( 1 ) on rotating in slides on the lug on a flank inclined more heavily the axis of the lug ( 25 ) and on loading in the counter direction presses with a flank inclined less to the axis of the lug ( 25 ) against the lug ( 25 ).  
     
     
         8 . A fastening system according to one of  claims 1  to  7 , in which the plastic material ( 7 ) is a plug for fastening the screw in a bore of a carrier material.  
     
     
         9 . A fastening system according to one of  claims 1  to  7 , in which the plastic material is a carrier material or a section of the carrier material.  
     
     
         10 . A fastening system according to one of  claims 1  to  9 , in which one clip bow ( 19 ) of the clip ( 17 ) is a spring bow which in the unloaded condition is inclined to the other clip bow ( 18 ) and with a clip ( 17 ) sled onto a flat carrier material is pivoted somewhat away from the other clip bow ( 18 ).  
     
     
         11 . A fastening system according to  claim 10 , in which the clip bow ( 19 ) designed as a spring bow at the free end comprises a suspension lug ( 21 ) bent away from the oppositely lying clip bow ( 18 ), for simplifying the sliding onto a flat material.  
     
     
         12 . A fastening system according to one of claims  10  or  11 , in which a clip bow ( 19 ) on the side facing the other clip bow ( 18 ) comprises barbs ( 22 ′,  22 ″) for position securement on a flat material.  
     
     
         13 . A fastening system according to one of  claims 1  to  12 , in which the clip ( 17 ) comprises several lugs ( 25 ) arranged symmetrically about the through-bore ( 23 ′,  23 ″).  
     
     
         14 . A fastening system according to one of  claims 1  to  12 , in which the at least one lug ( 25 ) comprises an end section ( 26 ) converging towards the free end, for the engagement into the at least one deepening ( 5 ) of the screw ( 1 ).  
     
     
         15 . A fastening system according to one of  claims 1  to  14 , in which the at least one lug ( 25 ) is bent out of the flat material of the clip ( 17 ).  
     
     
         16 . A fastening system according to  claim 15 , in which the at least one lug ( 25 ) is bent out of the edge regions of the two clip bows ( 18 ,  19 ) and the clip back ( 20 ).  
     
     
         17 . A fastening system according to one of the  claims 1  to  16 , in which the clip ( 17 ) is of metal, in particular a metal sheeting.