with no slots in the pump tube.You could get a pump that would drop in to a Disco, and still leave significant storage volume.

Would you be interested if it meant you pumped the gun like pruning shear, a lever on both sides?

Tough to make good looking...but would that kill your interest?

Yes.


Ask Val how many wanted one.

I think it's a great idea, and it would allow for much more power.
A simpler way would be a a plunger system, similar to the Philippines FARCO survival gun.
It shoud not be too difficult to fit in a 392 valve, and from there many possibilities.
C'mon Crosman do it!!!

to developing unwanted sidethrust to the crosshead and piston rod.

Unless a timing devise is located at the fulcrums of each lever. Much in the mannor of the involute spur gear arrangement we see applied too the common scissor jack.

the wine bottle corker I have has that sort of linkage and uneven pressure on the handles causes it to cant to one side.

regards,

Your concept sounds very cool - including the general advantage of side-pumpers that scope mounting flexibility isn't compromised.

But it's nevertheless true that many folks won't touch any airgun that doesn't look like a firearm - at least in bad light. No accounting for taste.

Steve

When charging these guns now it is similar to hedge clippers but with this design you'll have a rifle flopping aroung in between, right?

smaller than a 392, and a long side lever could be used? I pumped a similar setup to 2200 psi. with no problem with a mac-1 ext. billet lever.

The idea is to get a lot of stroke on a smallish diameter piston, say 760 size, but with leverage advantage, unlike the normal inline pump,and without the muzzle in the dirt (or toward your face) issues of inline pumps. I'd like to avoid a slot, both drop in fitment to many co2 rifles without modification to the gun, and to maximize the useful stroke.

Binding might be an issue, but less than with the grasshopper single side link of the old benjie pistols. A third link could be a way to manage timing,at the cost of bulk and complexity.

I'm imagining you'd charge this gun with the butt on the ground, probably kneeling, and get several shots per charge.

Because it wasn't really "scope friendly". The thing COULD have been redone to improve things, but wasnt.

But also, there hasn't been any so-called "improved linkage guns that show an honest superiority over the very simple linkage of many current designs. A problem with two handed cocking is you need to brace the gun against your thigh or a table or whatever. Hard to see any true benefit.

Multistage pumps seem to have the edge over any multi-link levers so far.

nut cracker.

Friction and effort on the out stroke would have to be managed carefully, the ergonomics on lifting a pair of levers aren't the greatest.

If so, what were they? I must'a missed them. Still do, in fact.

?t=1201307810

?t=1201324943
?t=1201324991
?t=1201325013

http://www.network54.com/Forum/79537/thread/1201325695/First+breakage+on+%26quot%3BPraying+Mantis%26quot%3B+linkage%21

Steve

I just don't see the need for that much mechanical advantage, my 1322 was easy to pump to 3600psi. I was thinking of converting the air tube I had started for a single stroke 1" piston to msp, I realized the valve volume would be enough to power a 9mm msp, a trick linkage would be useful there.

...I'm convinced they must be made much stronger than ordinary ones, because some folks will be inclined to pump them faster - so fast that the heat of compression will contribute to peak pressure and linkage stress.

I think that effect is what broke the multi-ratio ("telescopic") linkage you developed a few years back. Now THAT was a cool linkage!






Steve

Multi stage, so some effort in the upstroke, tougher ergonomically? That would slow the stroke rate, but increase heat input?

The annular storage chamber I'm imagining should speed heat loss,but the check valve would still be vulnerable.

It would be like putting a honking big motor in a sporty car, but then installing a stiff spring under the gas pedal to discourage using it to go fast. What's the point?

Steve

You are an innovative feller, scot.

Whats the chances of having a very small diameter piston with long stroke up front which is propelled by the contemporary scissors linkage.

Hidden in the buttstock is another piston of greater swept volume which will feed the small pistoned pump. This is a two stage pump once removed.

Now the cylinder in the buttstock will most likely not end up inline with the forward piston.

So the problem is linking the buttstock piston to the forward piston with some sort of linkage that is flexible.

For this I might suggest a push/pull throttle cable assembly. Which would easily pull the large piston yet have enough rigidity to push the large piston for air replenishing.

Now the throttle cable could be so designed so that the air from the large pistoned cylinder is transported to the forward pump thru the sheathing of the throttle cable which, at the small cylinder, is fastened to a fitting which was o-ringed so as to direct the air into the small cylinder yet allow the throttle wire to be fastened(in some way) to the forward pistons linkage.

Remember the similar over-under scheme I sketched up? Single scissor lever but the large
diameter piston is driven by slots in the side and external links either side - I
think you've used this before for a pumper.

Was your plan aimed at filling stage two with a super charge?

I found one of the rough sketches, finer details like stroke lengths, diameters not worked
out and the transfer port is exaggerated and placed far back to show where the transfer
occurs (it could be right up front). The 1st stage will use the tube slots as the intake.
The 2nd stage rear o-ring needs to stop before the slot at full extension. I wouldn't
mind seeing what you can make of this.

[IMG][/IMG]

but you can't move much air at good pressures with a non leveraged pump. I'd like to see 18 ft/lbs on no more than 4 fairly easy pumps per shot, air conserving with a 5-10 shot reservoir.