US2223730A

US2223730A - Method of attaching tips to pen nibs

Info

Publication number: US2223730A
Application number: US227467A
Authority: US
Original assignee: American Platinum Works
Current assignee: American Platinum Works
Priority date: 1938-08-30
Filing date: 1938-08-30
Publication date: 1940-12-03
Anticipated expiration: 1957-12-03

Description

Dec. 3, 1940. K. 1.. LEDIG 2 METHOD OF ATTACHING TIPS TO PEN NIBS Filed Aug. 30, 1958 ATTORNEY Patented Dec. 3, 1940 UNITED STATES PATENT OFFlCE METHOD OF ATTACHING TIPS TO PEN NIBS Application August so, ms, Serial No. 227,465 3 Claims. (01. 219-10) This invention relates to the manufacture of pen points and more particularly to a method of attaching tips to pen nibs.

Heretofore, tips have been attached to pen nibs by arc welding employing very high voltages, which were a source of danger to the workmen. Such high voltages are also difficult to manipulate on small objects such as a tip for a pen nib.

It is, therefore, an object of this invention, to

provide a method of attaching tips to pen nibs by employing relatively low voltages, not exceeding 30 volts.

The tips may be of spherical shape or any other suitable shape, and consist of hard metal, including hard metal alloy, for instance of an alloy of iridium or osmium or other hard metals, such as ruthenium, tungsten or molybdenum. The pen nib usually consists of precious metal or of a precious metal alloy, for example, an alloy of gold,

palladium, silver or the like, but may also consist of non-precious metals, such as steel, particularly stainless steel, or the like.

In U. S. Letters Patent #2,080,140, there is described a method of tipping a metallic nib having a recess with a metallic tip by means of resistance welding. It has now been found that it is possible to tip ametallic pen nib having no recess with a metallic tip, provided the initial contact between the tip and nib electrodes is fol-.

lowed by a certain and definite pressure on either the tip or the nib or both the tip and the nib, preferably on the nib, to cause a certain and definite movement toward each other for predetermined periods of time.

The purpose of the pressure isto bring the tip and the nib in more intimate contact and to permit the quick melting of a portion of the nib material at and adjacent to the point of contact.

point of the nib has flowed around the sides of Fig. 3 is a view of an apparatus adapted for employing the method ,for attaching tips to pen nibs.

Fig. 4 is a fragmentary plan view of the pen nib having a tip attached thereto, and

The pressure is continued until the metal at the Fig. 5 is a fragmentary side view of the pen nib shown in Fig. 4. Referring to the drawing, the end of the nib I to be tipped with the metallic tip 2 is substantially flat and is not provided with a recess. The i5 tip is substantially spherical or the like and has a diameter approximately equal to or slightly smaller than the width of the end portion 3 of the nib to be tipped. For instance, a pen nib having a thickness of 0.011" and a width of 0.030 10 is usually used in connection with a tip having a diameter of 0.0295 or 0.030".

On the first contact of tip 2 and nib l, the metal at the extreme end 3 of the nib will, during the flowing of the current begin to fuse, flowing '1 over the tip arranged below the nib. Under the slight; pressure exercised, tip and nib will come closer together. During this approach more and more metal of the nib at its extreme end will melt until finally the sides of the tip are completely 20 surrounded by the-metal of the nib.

Where the diameter of the tip is approximately equal to or slightly smaller than the width of the end of the nib the distance of the total movement of the electrodes will be approximately equal to the thickness of the pen nib.

A tip of great diameter requires more molten nib metal and, therefore, greater movement than a tip of small diameter, in order to become properly capped; and a thick pen nib will properly cap a tip of a given diameter with less movement than would be necessary in the case of a thin pen nib.

A pen nib comprised of a 14 k. gold alloy may have, for instance, -a thickness of approximately 85 0.020" and a width of 0.030" and is used in connection with a tip having a diameter of approximately 0.030". The relative movement of nib and tip will be approximately 0.020". A pen nib composed of a nickel steel alloy containing 18% nickel, 8% chromium and 2.5% molybdenum may have for instance a thickness of 0.011" and a width of 0.030" and the tip used in connection therewith may have a diameter of about 0.030". The relative movement of tip and nib toward each otherwill be approximately 0,011". This movement will not vary more than 10% depending on composition of the material and other factors.

Where the tip has a diameter substantially smaller than the width of the nib the movement should not exceed about $6 of the diameteroi the i s The voltage employed in thisinvention lies 5 betwen 0.5 and 30 volts, but the best results are obtained in the range from about 2 to '7 volts.

Nibs having a high melting point such as steel require a slightly longer time for the welding than stainless steel. Protective gases, for instance hydrogen, should be employed where a relatively long time is ,employedfor completion of the welding.

In Fig. 3 is shown an apparatus adapted to be arm I3 mounted upon a gear [4 which is in mesh.

with a small gear I5 mounted upon the shaft of an electric motor I6. The gear I4 is provided with a circular disc or collar H which is in constant contact with a brush l8, the latter being connected by a wire I9 to the secondary of a transformer 20, which is connectedthrough an adjustable resistance H to the clamp I. The above described timing device is merely by way of example, and obviously other forms of timing devices can be used without departing from the spirit of the invention, for instance, a Thyratron welding timer canbe used.

From the above description it will be seen that by the method herein disclosed there is no melting or softening of the hard metal tip. The ,metal of the nib is fused so that it flows around and holds the tip firmly as shown in Figs. 4 and 5. Due to thefact that there is no melting of the hard metal tip, the tips do not become overheated and crystallized. Accordingly it is possible to use highly polished, preformed metal tips; and grinding and polishing of the tip after it has been attached to the nib is eliminated.

The tip is made out of a high melting point material and the nib from a relatively low melting point material. This makes the welding process very simple and rapid, enabling mass production. Also, instead of using gold pen nibs and the like, a much more inexpensive material such as stainless steel can be effectively used for the pen nib.

The foregoing disclosure is to be regarded as descriptive and illustrative only, and not as restrictive or limitative of the invention, of which, obviously, embodiments may be constructed, in-

cluding many modifications, without. departing from the spirit and scope of the invention herein set forth and denoted in the appended claims.

Having thus described the invention, what is claimed as new and desired to secure by Letters Patent, is:

1. The method of tipping a metallic pen nib having a flat pointed end of greater width than thickness with a substantially spherical tip of relatively higher fusing point having a diameter approximately 'equal to the width of the end of the nib, comprising bringing the end of the nib to be tipped into engagement with the tip and passing an electric current of a voltage not in excess of 30 volts through said nib and tip to fuse only nib metal at the area of engagement of nib and tip while moving the fusing nib and the tip toward each otherefor a distance approximately equal to the thickness of the nib to be tipped, whereby the fused nib metal surrounds and firmly grips part of the tip.

2. The method set forth in claim 1 in which the nib is vertically suspended over the tip an the fusing nib is moved towards the tip,

3. The method of tipping a metallic pen nib having a fiat pointed end of a width of about 0.030" and of a thickness of between about 0.011" and about 0.020" with a substantially spherical tip having a diameter of about 0.030" and consisting of metal having a relatively higher fusing point than the metal of the nib, comprising vertically suspending thepen nib over the tip, bringing the end of the nib to be tipped into engagement with the tip and passing an electric current of a voltage not in excess of 30 volts through said nib and tip to fuse only nib metal at the area of engagement of nib and tip while moving the fusing nib and the tip toward each other for a distance approximately equal to the thickness of the pen nib.

FRANK VOIGT, Executor of last, will and testament of Karl K.

Ledig, Deceased.