Peter Twydle

Levers, Buttons and Bars

by Arthur Twydle

Levers, button and bars are the vital parts of self-filling fountain pens. There is such a wide variety of design that it is important to have an appreciation of the main types.

Most systems involve a bar which is in direct contact with the ink sac. This bar effects the compression of the sac by squeezing it in some way against the inner wall of the pen barrel. The two main mechanisms for doing this involve a lever or a button, and there are variations of all these components.


Simple bars

a) V type - a simple piece of sprung steel, both legs of equal length.

b) Crookbar - the crook being anchored in the bottom of the pen barrel. A single piece of sprung steel shaped like a shepherd's crook.

c) Two piece crook - Spring steel with solid bar. This will depress the sac more and so increase ink capacity.

To remove any of the three types, open the lever to 30 degrees. Insert a long, thin screwdriver between the barrel wall and bar and then push the driver hard to the bottom of the barrel. Give a half turn to flatten the crook, after which the bar should fall out or is easily removed with long nosed pliers. Do not forget to re-tension the crook before re-insertion using the driver inside the crook. Push firmly to reseat securely in the bottom of the barrel.

Swing bars

These are used in the better quality Conway Stewarts, and also some Waterman's and Eversharps. It is a solid rail in which, normally, two lugs are cut and stand proud. These are to meter the distance along which the bar is allowed to move when engaged with the two hooks on the lever.

You can only remove and replace a swing bar with the section and sac removed. Open the lever to 90 degrees and take a small penknife. Depress the 'top' lug on the swing bar. This will now fall out. Before replacing, adjust the lug to its original 30 degree position and then insert the bar into the barrel so that it engages with the hooks on the lever. You can use forceps or narrow nose pliers for this. You will hear the bar click into position.

Angle bars

These are used in Swan leverless pens - a solid bar attached to the twist button and angled off-centre which, when turned anticlockwise, flattens the sac against the barrel wall. ( A tip for 'leverless' Swans is always to ensure that the sac is a snug fit, otherwise the lever will not work properly.) To remove and replace the angle bar requires a special Swan tool, but these rarely go wrong anyway. Just be careful when removing the old sac.

Anchor bars

These are used in Parker Duofolds. It is a 3-piece pressure bar. The third leg contains a hook which anchors on the end of the barrel and is held in place by a button. Anchor bars do not require the back resistance from the section and are ideal for push fit sections.

Button bars

These are the most widely used and consist of a 2-piece bar i.e. a solid bar attached to a longer sprung bar. (These were made in 8 lengths from 1 " to 3 ") On depressing the bar, the resistance of the anchor point (in most cases beside a threaded section or sac peg) causes the spring to bow and pushes the solid bar out, thereby compressing the sac.

To remove an anchor or button bar you should theoretically pull them out after the button has been removed, but in practice the bars are often broken, corroded or stuck to the sac. It is much easier to remove them after removing the section. Use a little lighter fuel to soften the polymerised sac.

Replacing anchor or button bars is always done after the section, with sac attached, has been refitted, otherwise the sac may become screwed up. The bar is introduced at an angle and care must be taken not to deform the sac. On some pens, such as the Lucky Curve Duofolds, the bar must be aligned with the nib. After the bar is introduced, the button should be fitted in both cases. Anchor bars can be used as alternatives to normal button bars but the hole may have to be slightly enlarged.

NOTE: Generally, most button fillers have threaded sections (but there are exceptions) so it is important that when one finds a push fit section with a button filler (if it is not a very tight fit) a dab of shellac is necessary to ensure the pressure from the button and bar do not move it. Some barrels gave a steel ledge or ring as the 'anchor point' so be careful not to damage this when cleaning out the old sac.


a) Plastic button - used in cheaper, wartime school pens. The button is threaded for half its length and screws into the bottom of the barrel. After the threads disengage it becomes a normal push button.

b) Top hat button - also used in cheap, post-war school pens. Fitted through barrel mouth and anchored with a flat collar.

c) Twist button - a Swan patent used in Swans and Blackbirds. A brass screw with a cam action, usually used with a screw section. Part of the section thread is cut away to allow the conventional pressure bar to sit inside the thread. (The twist button on leverless Swans is a different design and is attached directly to the anglebar.)

d) Brass button - the most popular type which is sprung through the bottom of the barrel.

e) Aluminium button - part of an assembly secured to the two post-war Parkers - Victory and Duofold. The button fitted into a collar which is secured in the plastic pen.

NOTE: Some Conway Stewart button fillers have a total bar assembly screwed into the button end hole from the inside. The Stephens button cap must be removed with a small C spanner.


A lever is a simple 'key' anchored into an opening cut in the side of a pen barrel. Its function is to actuate a pressure bar which squeezes flat a rubber sac.

There is such a variety of lever designs and patents that it may be of interest to consider the development of the lever itself.

SHEAFFER - The most famous mechanical lever filler was patented in 1908 by  Walter Sheaffer. It was a long piece of metal about a third of the length of the whole barrel and sat in a slit cut in the side of the barrel. It is anchored by a short steel pin fitted through the barrel wall on which it can be pivoted.

The barrel was indented to allow a thumb nail to lift the lower end of the lever. When the lever was raised it lowered the attached pressure bar which squeezed the sac against the inner wall of the pen barrel thereby expelling the air. When the lever was returned flush with the barrel wall, the bar returned to its original position and the sac filled with ink.

WATERMAN were challenged not only by Sheaffer but by Parker, who were 'button focused' with the Jackknife and Duofold range. However, competition is a great driver for innovation and after variants such as the coin fillers, the box lever was Waterman's very successful attempt to combat the Sheaffer patent. This distinctive lever with the 'globe ideal' logo on the lever itself is hinged with a pin into its own box frame and the whole box is secured into the barrel by two clasps or lugs.

There were many patents and modifications to get round the Sheaffer and Waterman patents, but this often introduced design defects or unnecessary complexity. One example is the hinge lever assembly of Waterman. These look like broken box levers but are in fact two-part hinge assemblies and can be found in Waterman Ink Vue pens and some of the early Moores. They operate with a pump action.

The CONKLIN Crescent is not a lever but a hump-backed pressure bar, the hump protruding through the slit in the barrel wall. It does the same job as a lever. It is fitted from inside the barrel and held in position with a lock ring when not in use.

Some snippets

Lock levers. Some levers have a stop at 90 degrees. Some Summits have a lock bar anchored centrally inside the lever which stops against the inside of the barrel wall when the lever is opened at 90 degrees. Others, such as Swan, Skyline and other Eversharps have different locking or stopping devices.

'Modern' Side Levers - These are normally simple levers which flatten a crook bar and open to about 150 degrees (but are only effective at 90 degrees) or are levers with the two pointed lugs which engage in the rail of a swing bar - both common to Conway Stewarts and many other British pens. The lever is anchored with a ring of spring wire which sits in an internal groove inside the barrel. (Note: - always examine the groove carefully and ensure that all the old wire is cleaned out before replacement.)

Esterbrook - This lever operates against a crook bar with a spacer in the bottom of the barrel to stop any lateral movement of the bar. A plastic insert is installed in the barrel which stabilises the sac and the bar and at the same time ensures fuller compression of the sac by the bar when filling.

Tips on levers

1) Some levers are drilled with two sets of holes. This is so the same lever can be used with different width barrels.

2) Earlier levers (e.g. Sheaffer, Conklin, Moore) were hinged directly with a steel pin through the barrel. Great care should be taken when removing and replacing these pins as some barrels are very brittle.

3) Many overlay pens require removal of the overlay before any attempt is made to repair the lever. But conversely, the lever box may have to be removed before an overlay repair can be done.

4) There are two weak points on box levers which become obvious if any attempt is made to force open the lever against a hard fossilised sac:

a) the hinge point on lever and box

b) the clasp or lugs on the box, which also easily broken when attempting to remove the box from a barrel.

5) Generally, levers are not difficult to fit but great care is required if you wish to remove one from an old barrel for re-use. The easy way is to chip away at the old barrel or burn it so the old lever is removed intact. (Slowly and Carefully!!)

Do not forget that levers are part of the barrel assembly, so examine the barrel carefully - the slots, the retaining groove, the blind cap threads etc. If the barrel is in bad shape, it may pay you to look for another barrel rather than perform major surgery.

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