Brake equalizer with housing enclosing piston and shock absorber

An apparatus for equalizing pressure in fluid pressure-actuated system, comprising:

• a housing defining a chamber, said chamber having a closed end and an open end;
• an elastic diaphragm extending across the open end of the chamber;
• a piston within the chamber, said piston having a length L;
• and
• a shock absorber within the chamber between the closed end and the piston, said shock absorber having a length M, where L/M is substantially less than 0.23, and wherein the piston is dimensioned to translate freely along the chamber between the open end and the shock absorber in response to fluid pressure variations transmitted through the diaphragm to the piston.

An apparatus for equalizing pressure in fluid lines of a fluid pressure-actuated system, comprising:

• a housing defining a chamber, said chamber having a closed end and an open end;
• an elastic diaphragm extending across the open end of the chamber;
• a non-sealed piston within the chamber;
• and
• a shock absorber within the chamber between the closed end and the piston, wherein the piston is dimensioned to translate freely along the chamber between the open end and the shock absorber in response to fluid pressure variations transmitted through the diaphragm to the piston, wherein the piston is not bonded to the shock absorber and wherein the piston has a length L, the shock absorber has a length M, and L/M is substantially less than 0.5.

A piston for use in an apparatus for equalizing pressure in fluid lines of a fluid pressure-actuated system, wherein the apparatus includes a housing defining a chamber having a closed end and an open end, and a shock absorber having length M in the chamber at the closed end, said piston including:

• a first end facing the shock absorber;
• a second end opposite the first end;
• and
• a sidewall dimensioned so that the piston can translate freely along the chamber between the open end and the shock absorber in response to fluid pressure variations transmitted to the second end, without a seal between the sidewall and the chamber, wherein the piston has a length L, and L/M is substantially less than 0.5.