Denver--Leaking hose couplings can be a major source of frustration for hydraulics engineers. Caused by imperfect crimping of the coupling's shell around the hose, such leaks can disable costly hydraulic systems.
Now, engineers at The Gates Rubber Company say they've found a way to alleviate the problem. Using a new design on a coupling known as MegaCrimp, they've improved the seal between the inner diameter of a coupling's shell and the outer diameter of the hose that slips inside it.
Key to the new design is a patented device known as a "C" insert. In the final configuration, the "C" insert fits between the coupling's outer shell and the hydraulic hose. During crimping of a shell around a hydraulic hose, the "C" insert plays a vital role because it closes concentrically around the hose, thus sealing off any potential leakage paths. In essence, the unit provides a tight seal between the rubber hose and metal coupling.
In contrast, conventional couplings often do not yield good metal-to-rubber sealing as a result of the crimping process. Most couplings employ "multiple-finger" die sets, which crimp the coupling's shell around the hose. During crimping, the die sets often leave a flat spot on the coupling's shell. As a result, the shell doesn't fit concentrically around the hose.
The "C" insert eliminates that problem because it acts as a buffer between the shell and the hose. C-shaped teeth in the insert "flow," absorbing deformation caused by the crushing action of the die set. As a result, the "C" insert closes, forming a perfect circle. "On this coupling, the outside shell deforms, just as it would on a conventional coupling," notes Sherrie Mont, hydraulic applications engineer for Gates. "But the 'C' insert closes while the outside shell deforms, so it squeezes concentrically around the hose."
The design of the "C" insert also endows the coupling with another critically important feature: ease of installation. An advanced tooth profile on the inner diameter of the "C" insert "bites" the hose. This, in turn, enabled Gates engineers to employ a smaller diameter coupling stem. As a result, unlubricated hoses easily slide over the stem during installation. They are then held securely in place by a barb at the base of the stem.
By incorporating MegaCrimp couplings in hydraulic systems that operate at pressures ranging from 1,000 psi to 6,000 psi, Gates engineers say they can reduce leakage, simplify installation, and reduce customer inventory. Says Mont: "These benefits make it the most innovative coupling to be introduced in a long time."
Additional details...Contact Sherrie Mont, The Gates
Rubber Co., Box 5887, Denver, CO 80217, (303) 744-4855. Internet: http://www.gates.comgates .