Hydraulic Jack or Press Knob

thingiverse

If you have a hydraulic shop press, or frequently used hydraulic jacks, you know that it can sometimes be a bit awkward to use the pump handle to operate the release valve. Although not a big deal to do, if the slotted end of the handle gets a bit bunged up it can be tough to get onto the valve. And even when it fits on easily, twisting the handle does not give you all that much leverage or finesse. Besides, you really **shouldn't** need to be running it closed all that tightly to hold pressure for most tasks (but of course never, never rely on a hydraulic jack to hold a suspended load!!!). I designed this slip-on knob cover that mates with the jack's release valve stem. It extends outward to easily clear the base of the jack (see photos) and is a comfortable size for gripping with your fingers. It allows for fine adjustments if you want to release pressure slowly and has more than enough leverage when closing the valve. The outside of the knob shaft is nominally 0.75" so you can add a spring or clamp if you feel the need to do so. But the ones I have made grip the jack's release stem tightly enough that it doesn't seem necessary. In most cases it will snap onto the pin that extends through the jack's valve stem. A small relief is designed into the slot for that purpose. It can also be shimmed with a wrap or two of PTFE tape on the valve stem if it doesn't fit snugly enough. I have included two versions (0.450" ID and 10mm ID) which should work with most small metric jacks as well as many larger jacks such as found in 10 and 20 ton shop presses. You can of course scale them up or down to suit your jack as needed. Thanks for looking, I hope this helps you.