within a certain range since the position of the bolt 32 is fixed the sliding of the wedge 40 beneath the bolt 32 causes pivoting of the wedge 50 about the embedded first tooth 52 especially in the preferred embodiment in which the groove 48 has an upward slope as a result the second tooth 54 is driven into the pipe surface 56 after the second tooth 54 is embedded in the pipe surface further pivoting of the wedge 40 is inhibited but the wedge 40 may still slide relative to the bolt 32 until interference with the front edge 78 of the groove 48 prevents further motion in a preferred embodiment the front edge 78 of the groove 48 may comprise a raised lip 80 shown in fig8 to increase the contact area with the bolt 32 and as is shown in fig8 and 9 the shroud 60 may comprise an arch 82 adapted to accommodate the raised lip 80 those of ordinary skill in the art will recognize that the joint restraint described above and shown in fig1 12 can be used in many other applications for instance the joint restraint of the present invention can be used in conjunction with a plain ring to restrain a push on joint in which the two rings are joined by connecting bolts this type of application is similar to that disclosed in u s pat.