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Shock Absorbers (Dampers), again
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the
lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? -- www.wescottdesign.com |
Shock Absorbers (Dampers), again
Tim Wescott wrote: A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? -- www.wescottdesign.com I didn't read the previous thread, but if you are looking at those kind of loads, I'd think you should be looking at a standard hydraulic cylinder, tank and needle flow control valve. |
Shock Absorbers (Dampers), again
On Feb 5, 8:03*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? --www.wescottdesign.com Tim, there is a place NW of Redmond that has a heavy steel gate with a similar pivoting scheme. He has a chain drive an an electric motor to raise and lower the thing. It is not 18 ft long, but is still pretty heavy. Could you construct a similar mechanism for your gate? Paul |
Shock Absorbers (Dampers), again
It seems a bit confusing, when you stated in an earlier post that the gate
is a scissors-type gate, and they're normally opened and closed horizontally (not vertically). I wouldn't consider lifting something of that length and weight to be a safe (or practical) method of entry/exit. -- WB .......... metalworking projects www.kwagmire.com/metal_proj.html "Tim Wescott" wrote in message ... A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? -- www.wescottdesign.com |
Shock Absorbers (Dampers), again
On Feb 5, 11:03*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? --www.wescottdesign.com The damper on the forklift-sized fire door I was thinking of doesn't support any weight at all, the hinges do that. If this gate is statically balanced the only energy the dampener has to absorb came from the person shutting it. jsw |
Shock Absorbers (Dampers), again
On Feb 5, 10:03*am, Tim Wescott wrote:
A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? --www.wescottdesign.com I've seen cantilevered scissor gates with a supporting swivel caster at the opening edge. Maybe adding a caster would provide enough drag to prevent damage from slamming the gate. It would also lessen the load on the pivot hinges. |
Shock Absorbers (Dampers), again
"Tim Wescott" wrote in message ... A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? -- www.wescottdesign.com Years ago I saw a hydraulic cylinder with a cushion at the end of the stroke. Instead of the cylinder bottoming out harshly the last bit of oil would flow through a smaller orifice. One could use a flow control on both stages to make the gate close at a slower rate near the end of the motion. http://www.hydraulic-equipment-manuf...articles2.html Steve |
Shock Absorbers (Dampers), again
"Tim Wescott" wrote in message
... A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? -- www.wescottdesign.com Call this guy. Mike Rotella 216-433-7766 http://www.control-line.com/motioncontrol.asp Tell him I sent you. If he can't sell direct to you, I'll sell it to you at my actual cost plus shipping. ....It's *NOT* a $50 device. Regards, Joe Agro, Jr. (800) 871-5022 01.908.542.0244 Automatic / Pneumatic Drills: http://www.AutoDrill.com Multiple Spindle Drills: http://www.Multi-Drill.com Production Tapping: http://Production-Tapping-Equipment.com/ Flagship Site: http://www.Drill-N-Tap.com VIDEOS: http://www.youtube.com/user/AutoDrill V8013-R |
Shock Absorbers (Dampers), again
On Fri, 05 Feb 2010 12:30:47 -0500, Wild_Bill wrote:
It seems a bit confusing, when you stated in an earlier post that the gate is a scissors-type gate, and they're normally opened and closed horizontally (not vertically). I wouldn't consider lifting something of that length and weight to be a safe (or practical) method of entry/exit. And you call yourself "Wild" Bill... First, it came that way, and second, it's counterbalanced with springs. There's not much load out on the end of it, but if it's going fast when it hits the stop it sure makes a bang. -- www.wescottdesign.com |
Shock Absorbers (Dampers), again
On Fri, 05 Feb 2010 09:32:43 -0800, Jim Wilkins wrote:
On Feb 5, 11:03Â*am, Tim Wescott wrote: A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? --www.wescottdesign.com The damper on the forklift-sized fire door I was thinking of doesn't support any weight at all, the hinges do that. If this gate is statically balanced the only energy the dampener has to absorb came from the person shutting it. And I have very energetic children with very undamped enthusiasm. The gate is partially balanced with springs, but you can shut (or open) it by pulling it just over center then letting go -- it gets up quite a head of steam by the time it hits a stop. -- www.wescottdesign.com |
Shock Absorbers (Dampers), again
On Feb 5, 2:43*pm, Tim Wescott wrote:
On Fri, 05 Feb 2010 09:10:18 -0800, wrote: On Feb 5, 8:03*am, Tim Wescott wrote: A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? --www.wescottdesign.com Tim, there is a place NW of Redmond that has a heavy steel gate with a similar pivoting scheme. He has a chain drive an an electric motor to raise and lower the thing. It is not 18 ft long, but is still pretty heavy. Could you construct a similar mechanism for your gate? Yabut. *We're far enough out in the boonies that we lose power at least once every winter, and the power line from the shop to the gate is hosed and needs to be replaced -- I not only need a round tuit, I need to rent a @#$% ditch witch _and_ figure out where the old line is. So whatever else it does, it has to work manually, at least sometimes. --www.wescottdesign.com Just power up the old line and dig crossways to it. You'll know as soon as you hit it. :) Karl |
Shock Absorbers (Dampers), again
On Sat, 06 Feb 2010 00:50:14 -0800, wrote:
On Feb 5, 2:43Â*pm, Tim Wescott wrote: On Fri, 05 Feb 2010 09:10:18 -0800, wrote: On Feb 5, 8:03Â*am, Tim Wescott wrote: A 120 pound gate, 18 feet long and 3 feet high, hinged at one of the lower corners and supported by a damper that is pivoted to the top corner and working at a 45 degree angle, puts a 510 pound load on the damper _just_ to keep the gate still -- decelerating the gate takes even more load, to the tune of 1700 pounds if you want to close the gate in one second (that's assuming constant deceleration over 45 degrees in 1/2 second). (I decided I didn't want to close it that fast). Anyone who suggested a fire-door damper -- where can I find one that'll support a ton? --www.wescottdesign.com Tim, there is a place NW of Redmond that has a heavy steel gate with a similar pivoting scheme. He has a chain drive an an electric motor to raise and lower the thing. It is not 18 ft long, but is still pretty heavy. Could you construct a similar mechanism for your gate? Yabut. Â*We're far enough out in the boonies that we lose power at least once every winter, and the power line from the shop to the gate is hosed and needs to be replaced -- I not only need a round tuit, I need to rent a @#$% ditch witch _and_ figure out where the old line is. So whatever else it does, it has to work manually, at least sometimes. --www.wescottdesign.com Just power up the old line and dig crossways to it. You'll know as soon as you hit it. :) Karl Aw dangit -- that's such a good idea, but its got a dead short that blows the breaker immediately. But thanks for the help -- maybe next time I'll be able to use it. -- www.wescottdesign.com |
Shock Absorbers (Dampers), again
On Feb 5, 4:43*pm, Tim Wescott wrote:
Yabut. *We're far enough out in the boonies that we lose power at least once every winter, and the power line from the shop to the gate is hosed and needs to be replaced -- I not only need a round tuit, I need to rent a @#$% ditch witch _and_ figure out where the old line is. So whatever else it does, it has to work manually, at least sometimes. --www.wescottdesign.com Ok, I do understand about the round tuit. So lets convert the mechanism to a manual cranking system. Let the kids crank it up and crank it down. Paul |
Shock Absorbers (Dampers), again
You don't really need a mechanism to follow the entire range of motion, you
just need a snubber that effects/engages (maybe) the last 4-10" of closing. A hydraulic cylinder with a built-in snubber would probably be more difficult to locate and/or more expensive. A snubber could be a common cylinder with a light duty spring to extend the ram, and a needle/restrictor valve to adjust how fast the ram can be pushed into the cylinder. The check valve in parallel with the restrictor would be optional. The spring will slowly extend the ram. But it's still a scissors gate. -- WB .......... metalworking projects www.kwagmire.com/metal_proj.html "Tim Wescott" wrote in message ... On Fri, 05 Feb 2010 12:30:47 -0500, Wild_Bill wrote: It seems a bit confusing, when you stated in an earlier post that the gate is a scissors-type gate, and they're normally opened and closed horizontally (not vertically). I wouldn't consider lifting something of that length and weight to be a safe (or practical) method of entry/exit. And you call yourself "Wild" Bill... First, it came that way, and second, it's counterbalanced with springs. There's not much load out on the end of it, but if it's going fast when it hits the stop it sure makes a bang. -- www.wescottdesign.com |
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