Rams, Cylinders or Pistons?

[gruntstripe]

Hi, I am writing up some I/O lists. In most of the old lists I've found around here pnuematic cylinders are referred to as rams. I'd prefer to call them what I just did. What do you call them?

[TimWilborne]

I call them cylinders whether they are pneumatic or hydraulic. Also as far as the direction of the cylinder I prefer Advance and Retract. Some use in, out, left, right, etc a there always seems to be confusion on what is the front and back of the machine, etc. Advanced and Retracted seems to be clear when diagnosing machines where the cylinder is suppose to be or which switch to look at

[TConnolly]

Well, if we want to get really technical here, a piston and a cylinder are combined to make a ram. But generally the terms are interchangable.

[BobLfoot]

Coming from an agricultural background I first learned of hydraulic rams on farm machinery from my father. When I went to work as a lad in the factory every thing air was called a cylinder. So I guess I use both terms. My question to you is what mnemonic do you use on schematic drawings for the valves controlling rams or cylinders. Quite often I see {SOL} for solenoid, but I really like the japenese mnemonic of {YV} for solenoid. Thats "Y" "V"alve if you think about it makes a lot of sense and is shorter to write as well. Plus most older Japanese PLC's used X for inputs and Y for outputs.

[gruntstripe]

Hi, Yes, schematics, if only. Drawing those will be my next task! 'YV' sounds sensible. Thanks.

[gravitar]

I've always heard "air cylinder", "pneumatic cylinder", "pneumatic actuator", etc. used in an industrial setting. I would expect that the term "Ram" would be for a special purpose like an arbor press cylinder, staking cylinder, something like that. As far as electrical drawing notation and output descriptions, I've followed the standard (American) convention of "solenoid" or "SOL". But I do agree that isn't as self-describing as it should be when the solenoid is just a part of a valve! I think "solenoid" became popular because, from strictly an electrical perspective, it is irrelevant what the solenoid is actuating. It is just a wound coil and you're passing current through it. Anything else is the mechanic's responsibility to understand :)

[TimWilborne]

I usually think of a "Ram" as seen on a hydraulic press such as a punch.

[Sleepy Wombat]

Called tem cylinders lately in program however i think i prefer RAM.

[fluidpower1]

Definitions from Hydraulics & Pneumatics "Fluid Power Handbook & Directory" Glossary "Cylinder, piston type — A cylinder in which the piston has a greater cross-sectional area than the piston rod." Added by me: Usually Double Acting (Can have force Extending/Retracting) Can be a single Rod or have Rod's extending from both ends "Double Rod Cylinder." "Cylinder, plunger (ram) — A cylinder in which the piston has the same cross-sectional area as the piston rod." Added by me: Always Single Acting, must be returned by an external force. Can be Single Acting Extend or SIngle Acting Retract but are always SINGLE ACTING. It's in the book.

[TimWilborne]

Thanks for the definition Fluidpower1 and welcome to the forum. I look forward to your post. For those of you who don't go the Ron's site, Patchn, Fluidpower1 and Peter can answer most of your hydraulic questions Also Fluidpower1 is Bud in THIS post

[Spanner]

A Lecturer I once had used insist on them being referred to as "Pneumatic Linear Actuators" but here in the real world I find they're generically called "Cylinders" (Incorporates the solenoid controls as well) with "Extend" and "Retract" limits. (CYL - Cylinder, ELS - Extend limit Switch, RLS -Retract Limit Switch etc).

[Groo]

I thought rams would be competition