telescoping piston

telescoping piston

Joined: September 25th, 2006, 2:19 pm

August 11th, 2012, 7:23 pm #1

I dabbled with a similar design in the past where the 1st stage pressure was matched with the piston spring loaded trip mechanism.

This plan requires proximity of push pins to chamber front wall to move locking collar off center of steel retaining balls.

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Joined: April 1st, 2009, 3:18 am

August 11th, 2012, 9:19 pm #2

Used spring assisted ball bearing placed radially. The bearings push inward upon the smaller piston shaft, which has a groove to allow the bearings to rest. The required 'effort' to break the second stage is a little more than the effort of compressing the larger swept area... Works very well as an SSP. However, the original design reason was to make a multi pump gun on such a system - oops! Didn't work for obvious reasons, of course. So, when a large swept volume SSP is built, said piston will in fact be used in it.

"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."
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Joined: September 25th, 2006, 2:19 pm

August 11th, 2012, 11:17 pm #3

Why would such not work in a MSP? nt
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Joined: April 1st, 2009, 3:18 am

August 12th, 2012, 2:00 am #4

...but the particular project design I came up with it wouldn't. What was happening is the valve pressure was causing the second piston stage to prematurely collapse.

"The majority of things in our lives are created by folks no smarter than the rest. Afterall, the world is comprised, and operated by C average people intellctually, academically, and morally. These people are often the great pioneers that set the precedent for what excellence should be."
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Joined: June 25th, 2002, 1:34 pm

August 12th, 2012, 11:43 am #5

I dabbled with a similar design in the past where the 1st stage pressure was matched with the piston spring loaded trip mechanism.

This plan requires proximity of push pins to chamber front wall to move locking collar off center of steel retaining balls.

n/t
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Joined: June 25th, 2002, 1:34 pm

August 12th, 2012, 11:47 am #6

I dabbled with a similar design in the past where the 1st stage pressure was matched with the piston spring loaded trip mechanism.

This plan requires proximity of push pins to chamber front wall to move locking collar off center of steel retaining balls.

a big spring behind it that would compress as the smaller piston goes forward? TIA. n/t
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Joined: July 29th, 2012, 9:21 pm

August 12th, 2012, 3:25 pm #7

you'd be doing the extra work to compress the spring without any benefit. It'd be analogous to adding pump headspace.
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Joined: September 25th, 2006, 2:19 pm

August 12th, 2012, 5:25 pm #8

n/t
will be determined by whatever pressure one chooses for the first stage which would be surface area of the pins 2X . Air pressure is not expected or forseen to trip the clutch but the force against the rear wall pushing the pins forward with linkage will. But that has to be determined according to chosen volumes and compression ratios
Fine tuning insofar as pin length will be critical to minimize head space there but some head space will always be present and same for each stroke.

I worry about the large piston firing forward with perhaps too much velocity if 1st stage pressure were high which one would be inclined to do for an SSP format.
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lhd
Joined: November 22nd, 2002, 10:41 pm

August 13th, 2012, 7:38 pm #9

you'd be doing the extra work to compress the spring without any benefit. It'd be analogous to adding pump headspace.
The extra energy required to compress that spring could be returned to pumping force as the second stage commenced.
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Joined: July 29th, 2012, 9:21 pm

August 14th, 2012, 3:23 am #10

then the spring could only make second stage pumping harder. Here's what I think we're talking about.

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So the spring preload takes the place of the ball detents, and once the 1st-stage piston bottoms out the spring begins to compress and the second-stage piston keeps moving. The problem is that the spring can only increase the force needed to compress the second stage, and there's no way to get the energy back.
Last edited by Hudson12tum on August 14th, 2012, 3:24 am, edited 1 time in total.
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