Pivotable clamping electrical heating device for a thermoplastic pipe welding jig

In a heating device for a welding jig having two guide arms with clamping devices for securing in place one of plastic pipe sections and plastic moldings to be welded together, said clamping devices being displaceable in relation to each other, and having two semi-circular electrical heating plates with facing interior receptacles and free ends which are connectable to each other, the improvement comprising:

• a receptacle radius of the facing interior receptacles (14, 24) of the semi-circular electrical heating plates (11, 21) being one of equal to and greater than an inner pipe radius of an outer inner pipe circumference of an inner pipe (40) on which an outer pipe (41) to be welded is slipped,
• a plate radius of an outer plate circumference (15, 25) of the semi-circular electrical heating plates (11, 21) being greater than an outer pipe radius of an outer pipe circumference of the outer pipe (41),
• the semi-circular electrical heating plates (11, 21) having radially outwardly directed extensions (12, 16, 22, 26) on said free ends, said radially outwardly directed extensions having, on extension sides facing each other, recesses (13, 17, 23, 27) to receive the guide arms (45, 46) of the welding jig,
• the semi-circular electrical heating plates (11, 21) having connecting points disposed in the radially outwardly directed extensions (12, 16, 22, 26) outside of said recesses (13, 17, 23, 27) for the guide arms (45, 46),
• a recess distance between the centers of the recesses corresponding to a guide arm distance between the center longitudinal axes of the guide arms, and
• a plate distance between the receptacle center of the receptacle formed by the semi-circular electrical heating plates and the centers of the recesses corresponding to one half said recess distance.