Spacer for concrete reinforcing bars

Claim 1

A ONE-PIECE CYLINDRICAL DISC SPACER FOR THE LONGITUDINAL ALIGNMENT OF REINFORCING BARS WHICH ARE LAID IN CONCRETE AND TENSIONED TO REINFORCE THE CONCRETE, SAID ONE-PIECE DISC HAVING AN OUTER RING, AN INNER RING, SAID OUTER RING BEING INTERRUPTED BY SUBSTANTIALLY STRAIGHT GUIDING WALLS WHICH PROJECT BEYOND THE PERIPHERY OF SAID OUTER RING, SAID GUIDING WALLS EXTENDING INWARDLY TO DEFINE A MOUTH OPENING TO SAID INNER RING, SAID INNER RING HAVING ITS BASE PORTION WHICH IS REMOTE FROM SAID OPENING SQUARED AND THEREBY FORMING WITH SAID GUIDING WALLS A KEYHOLE WITH A SQUARED BASE INTO WHICH THE REINFORCING BAR IS FITTED, SPOKES INCLUDING IDENTED PORTIONS DISPOSED BETWEEN AND CONNECTING SAID INNER RING AND SAID OUTER RING FOR TAKING UP STRESSES WHEN THE SPACER IS CLAMPED ONTO THE REINFORCING BAR AND A STAY WHICH PROJECTS AWAY FROM THE SQUARED BASE OF THE KEYHOLE SLOT INTO PROXIMITY WITH THE INSIDE OF THE OUTER RING TO SERVE AS A STOP FOR PREVENTING EXCESSIVE BENDING OF THE KEYHOLE SLOT UNDER EXTERNAL STRESS.