Coupling gasket and bar linkage for friction-fit range reducer

A seal for a pipe coupling, the seal comprising:

• an outer gasket defining a radially inner surface, the radially inner surface defining a plurality of grooves;
• and
• an inner gasket separably joined to the outer gasket, the inner gasket defining a radially outer surface, the radially outer surface defining a plurality of ridges, each of the plurality of ridges extending radially outward relative to an axis of the inner gasket, the plurality of ridges comprising:
• a first ridge, each of a first side surface and a second side surface of the first ridge angled in cross-section with respect to a radial direction of the inner gasket towards a first axial end of the inner gasket when the inner gasket is in an uncompressed state;
• and
• a second ridge, each of a first side surface and a second side surface of the second ridge angled in cross-section with respect to the radial direction of the inner gasket towards a second axial end of the inner gasket when the inner gasket is in the uncompressed state;
• wherein the radially outer surface of the inner gasket contacts the radially inner surface of the outer gasket.

A pipe coupling comprising:

• a coupling body defining a first body end and a second body end, a coupling bore defined in and extending through the coupling body from the first body end to the second body end;
• a first end ring attached to the first body end, the first end ring comprising a first seal and a first split ring, the first seal disposed within the first split ring, the first split ring defining a first ring end and a second ring end, the first split ring configured to compress the first seal radially inward in a tensioned state;
• a second end ring attached to the second body end, the second end ring comprising a second seal and a second split ring, the second seal disposed within the second split ring, the second split ring defining a first ring end and a second ring end, the second split ring configured to compress the second seal radially inward in a tensioned state;
• and
• a bar linkage comprising:
• a first bar configured to be oriented parallel to an axis of the pipe coupling, at least when the pipe coupling couples pipes of equal diameter, and span two end rings thereof;
• a second bar configured to be oriented parallel to the axis of the pipe coupling, at least when the pipe coupling couples pipes of equal diameter, and span the two end rings thereof;
• and
• a tensioner joining the first bar to the second bar in an assembled condition of the bar linkage and configured to draw the first bar towards the second bar, the first bar and the second bar able to be angled with respect to each other and with respect to the axis of the pipe couple in a tightened condition of the pipe coupling, at least when the pipe coupling couples pipes of unequal diameter;
• each of the first bar and the second bar intersecting an axis of the tensioner, the bar linkage installable in and removable from the pipe coupling in the assembled condition;
• and
• wherein the bar linkage is engaged with the first end ring and the second end ring, the first bar extending between the first ring end of the first end ring and the first ring end of the second end ring and the second bar extending between the second ring end of the first end ring and the second ring end of the second end ring.

A pipe coupling comprising:

• a coupling body defining a first body end and a second body end, a coupling bore defined in and extending through the coupling body from the first body end to the second body end;
• a first end ring attached to the first body end, the first end ring comprising a first seal and a first split ring, the first seal disposed within the first split ring, the first split ring defining a first ring end and a second ring end, the first split ring configured to compress the first seal radially inward in a tensioned state;
• a second end ring attached to the second body end, the second end ring comprising a second seal and a second split ring, the second seal disposed within the second split ring, the second split ring defining a first ring end and a second ring end, the second split ring configured to compress the second seal radially inward in a tensioned state;
• and
• a bar linkage comprising:
• a first bar configured to be oriented parallel to an axis of the pipe coupling and span two end rings thereof;
• a second bar configured to be oriented parallel to the axis of the pipe coupling and span the two end rings thereof;
• and
• a tensioner joining the first bar to the second bar and configured to draw the first bar towards the second bar;
• each of the first bar and the second bar intersecting an axis of the tensioner;
• wherein the bar linkage is engaged with the first end ring and the second end ring, the first bar extending between the first ring end of the first end ring and the first ring end of the second end ring and the second bar extending between the second ring end of the first end ring and the second ring end of the second end ring.