Double-ended flexible pipe joint having stacked co-axial primary and secondary annular elastomeric flex elements

A double-ended flexible pipe joint comprising:

• An outer housing having a first end and a second end;
• a first extension pipe extending from the first end of the outer housing, the first extension pipe having an inner flange within the outer housing and an outer flange within the outer housing;
• a first primary annular elastomeric flex element disposed within the outer housing and mounting the outer flange of the first extension pipe to the outer housing;
• a second extension pipe extending from the second end of the outer housing, the second extension pipe having an inner flange within the outer housing and an outer flange within the outer housing;
• a second primary annular elastomeric flex element disposed within the outer housing and mounting the outer flange of the second extension pipe to the outer housing;
• an inner housing disposed within the outer housing, the inner flange of the first extension pipe being disposed within the inner housing, and the inner flange of the second extension pipe being disposed within the inner housing;
• a first secondary annular elastomeric flex element disposed within the inner housing and mounting the inner flange of the first extension pipe to the inner housing;
• and
• a second secondary annular elastomeric flex element disposed within the inner housing and mounting the inner flange of the second extension pipe to the inner housing;
• wherein tension upon the first and second extension pipes places each of the first and second primary flex elements and each of the first and second secondary flex elements in compression;
• and
• wherein the first and second secondary flex elements are mounted to the inner housing for containing fluid pressure within the first and second extension pipes so that the first and second primary flex elements are not subjected to the fluid pressure within the first and second extension pipes.

A double-ended flexible pipe joint comprising:

• An outer housing having a first end and a second end;
• a first extension pipe extending from the first end of the outer housing, the first extension pipe having an inner flange within the outer housing and an outer flange within the outer housing;
• a first primary annular elastomeric flex element disposed within the outer housing and mounting the outer flange of the first extension pipe to the outer housing;
• a second extension pipe extending from the second end of the outer housing, the second extension pipe having an inner flange within the outer housing and an outer flange within the outer housing;
• a second primary annular elastomeric flex element disposed within the outer housing and mounting the outer flange of the second extension pipe to the outer housing;
• an inner housing disposed within the outer housing, the inner flange of the first extension pipe being disposed within the inner housing, and the inner flange of the second extension pipe being disposed within the inner housing;
• a first secondary annular elastomeric flex element disposed within the inner housing and mounting the inner flange of the first extension pipe to the inner housing;
• and
• a second secondary annular elastomeric flex element disposed within the inner housing and mounting the inner flange of the second extension pipe to the inner housing;
• wherein tension upon the first and second extension pipes places each of the first and second primary flex elements and each of the first and second secondary flex elements in compression;
• and
• wherein the first and second primary flex elements and the first and second secondary flex elements are stacked in a coaxial fashion and share a common center of rotation, the first and second primary flex elements are disposed at a common first radius from the common center of rotation, the first and second secondary flex elements are disposed at a common second radius from the common center of rotation, and the second radius is smaller than the first radius.