fountainbel
Member
NEW CONID PUMP FILLER :
I've just made a prototype pump filler, inspired by the Parker Vacumatic, however using a piston instead of the wear sensible rubber diaphragm.
This system will probably be offered on the CONID pens alternatively to the plunger filler, since some people may be reluctant towards the plunger filler .
Attached a few pictures showing the set-up.
Note the double O ring set-up & the deepened ring section between both O rings, filled with silicone grease ensuring long functionality at low friction.
The filling stroke being 12 mm, ink volume 2.2 cm3 , which is taken- in after applying only 5 pumping strokes.
Emptying the fully filled pen over the small bypass bore takes approximately 15 pumping strokes
The stainless breather tube fits on the extension stud of a standard Bock nib assembly.
A Teflon restriction tube needs to be installed in the stainless breather tube bore.
NEW CONID PLUNGER FILLER:
The classical piston seal on most plunger fillers consists of a specially fabricated rubber seal which is mounted cupped in a back-up washer providing a check-valve function when pulling the plunger out.
Al though this design works well, the actual problem is making a precise replacement piston seal.
When designing the PF Tribute I reflected already on making a new piston seal , which would use standard of the shelf O rings.
In the meantime I designed, made & tested some prototypes of the "floating O ring' piston seal, and it works perfectly !
The O ring is mounted on a conical seat of the plunger head.
When pushing the plunger down, the O ring "climbs up" the cone (due to its pretension in the barrel bore) ensuring a perfect vacuum seal.
When pulling the plunger out, the O ring -being in the wider filling chamber- is slightly restricted to enter the ink chamber and is pushed to the smallest cone diameter before entering the ink chamber;
Given the inner diameter of the O ring is larger as the small diameter of the cone seat, the ink can flow back to the front of the piston.
An additional transversal groove in the plunger head increases the potential ink flow.
On the attached pictures one can see the design & the shifted position of the O ring elements in both stages.
Note the higher contact surface pressure -hence larger contact surface- of the O ring when the plunger is slightly pushed down.
The extra static O ring shown on the plunger head top is used as a "shut-off " valve & seals against a conical seat on the section.
Both version will be alternatively applied on the CONID pens.
And now working on my own screw-piston filler!
Francis
I've just made a prototype pump filler, inspired by the Parker Vacumatic, however using a piston instead of the wear sensible rubber diaphragm.
This system will probably be offered on the CONID pens alternatively to the plunger filler, since some people may be reluctant towards the plunger filler .
Attached a few pictures showing the set-up.
Note the double O ring set-up & the deepened ring section between both O rings, filled with silicone grease ensuring long functionality at low friction.
The filling stroke being 12 mm, ink volume 2.2 cm3 , which is taken- in after applying only 5 pumping strokes.
Emptying the fully filled pen over the small bypass bore takes approximately 15 pumping strokes
The stainless breather tube fits on the extension stud of a standard Bock nib assembly.
A Teflon restriction tube needs to be installed in the stainless breather tube bore.
NEW CONID PLUNGER FILLER:
The classical piston seal on most plunger fillers consists of a specially fabricated rubber seal which is mounted cupped in a back-up washer providing a check-valve function when pulling the plunger out.
Al though this design works well, the actual problem is making a precise replacement piston seal.
When designing the PF Tribute I reflected already on making a new piston seal , which would use standard of the shelf O rings.
In the meantime I designed, made & tested some prototypes of the "floating O ring' piston seal, and it works perfectly !
The O ring is mounted on a conical seat of the plunger head.
When pushing the plunger down, the O ring "climbs up" the cone (due to its pretension in the barrel bore) ensuring a perfect vacuum seal.
When pulling the plunger out, the O ring -being in the wider filling chamber- is slightly restricted to enter the ink chamber and is pushed to the smallest cone diameter before entering the ink chamber;
Given the inner diameter of the O ring is larger as the small diameter of the cone seat, the ink can flow back to the front of the piston.
An additional transversal groove in the plunger head increases the potential ink flow.
On the attached pictures one can see the design & the shifted position of the O ring elements in both stages.
Note the higher contact surface pressure -hence larger contact surface- of the O ring when the plunger is slightly pushed down.
The extra static O ring shown on the plunger head top is used as a "shut-off " valve & seals against a conical seat on the section.
Both version will be alternatively applied on the CONID pens.
And now working on my own screw-piston filler!
Francis
