US2153651A - Fountain pen - Google Patents

Description

pril 11, 1939. A. H. s'n-:NERSEN FOUNTAIN PEN Original Filed June 3, 1935 faz/erw: 1 ZZberZ He/efen,

Patented Apr. 11, 1939 UNITED STATES PATENT omer Application June 3, 1935,

Serial No. 24,663

Renewed September 12, 1938 8 Claims.

This invention relates to fountain pens and pertains particularly to self-filling fountain pens of the piston type, i. e., the type having a piston operable in the pen barrel to elfect the filling of the ink reservoir.

One of the objects of the invention is the provision of an improved construction for a fountain pen of the piston type which will facilitate the feeding of ink from the ink reservoir to the pen point so as to keep the pen point constantly supplied with ink during use of the pen in writing.

Another object is the provision of an improved construction for the piston of a fountain pen of the sort specied W ch will render the filling of the pen more certain.

Other and further objects of the invention will be pointed out or indicated hereinafter or will be apparent from the following description of the invention, or upon use of pens embodying it.

For the purpose of aiding in an explanation of the invention, I show in the accompanying drawing forming a part of this specification, and hereinafter describe, certain structural forms in which the invention may be embodied. It is to be understood, however, that these are presented merely for purpose of illustration, and that they are not to be interpreted in any fashion calculated to limit the appended claims short of the true and most comprehensive scope of the invention in the art.

In said drawing,

Fig. 1 represents a shortened longitudinal section of a fountain pen embodying the invention;

Fig. 2 is a part longitudinal section of the same construction but showing certain of the parts in other positions;

Fig. 3 is a transverse section on approximately line 3 3 of Fig. 1;

Fig. 4 is a longitudinal sectional detail showing a somewhat modified form of construction;

Fig. 5 is a transverse section on substantially line 5 5 of Fig. 4;

Fig. 6 is a part longitudinal section showing a second modified construction;

Fig. 7 is a transverse section on substantially line 'l-- of Fig. 6; and

Fig. 8 is a part longitudinal section like Fig. 2, but showing the relationship of parts during downward movement of the piston.

This invention relates primarily to that type of self-filling fountain pens wherein the pen barrel affords a cylindrical ink reservoir in which a piston is operable to induce a negative pressure behind the piston on its downward stroke, the evacuated portion of the barrel being placed in communication with the rpen section when the piston, at the end of its downward or inward stroke, reaches a clearance space at the lower end of the barrel, thereby permitting induction of ink through the ink-feeding passages of the pen 5 section and into the reservoir above the piston. Pens of this type heretofore employed have shown a tendency to starve the pen point in the course of continuous and rapid writing, due to insuciently free feed of ink from the reser- 10 voir past the piston. This has been found to occur even when the clearance space extends about the entire periphery of the piston. It is one of the objects of the present invention to obviate this diiiiculty without involving any increase in the external diameter of the pen barrel at this point, and without weakening the barrel in this locality. The manner in which these and Various other objects and advantages of the present invention are obtained, as well as the nature and character of the invention, will be ascertained most readily by a detailed consideration of the illustrative embodiments shown in the accompanying drawing, which embodiments, will now be described. The pen includes a barrel I0 which affords a bore or internal cavity lila of uniform cross-sectional size and contoury which cavity constitutes an ink reservoir. At its lower terminus it merges into a cavity Illb of greater cross-sectional size such as to aiTord a clearance space for the piston as hereinafter described.

In the upper end of the barrel is xed a bushing II which supports a washer I2, and also in the upper end of the barrel is secured a sleeve I 4 35 having a cavity which houses a plurality of layers I5 of packing material, all or some of which may be exible and compressible. This packing is compressed against the washer I2 by the screwing down of the sleeve I4. The bushing Ii, plate I2, sleeve I4 and packing material I5 are provided with axial apertures which align to aiord a passage for the piston rod I6.

The piston rod, as seen more particularly in Fig. 2, comprises a core Ia of metal wire and a sheath I6b of hard rubber vulcanized thereon. The upper end portion of the core extends beyond the sheath and has a jarnb nut Il and a stepped nut I8 threaded thereon. A short distance from its lower end the sheath is formed with a peripherally projecting shoulder IBc. Fitted on the lower end portion of the sheath is a rigid collar I9, of hard rubber, which is counterbored to accommodate and abut the shoulder |60. Centered on the sheath below this 5 Vbar has the conventional ink collar I9 is a disk 20 of flexible rubber, said disk being of substantially greater diameter than the diameter of the barrel bore Ia and of somewhat lesser diameter than the diameter of the cavity Ib. The lower end of the core I6a projects beyond the lower end of the sheath and has screwthreaded thereon a hard rubber spider nut 2l, the upper face of which is frusto-conical in form and provided with a plurality of longitudinally extending slots 2Ia. Nut 2l is set up tightly against the lower end of the sheath I6b below disk 20.

The flexible disk 20 is provided with a plurality of apertures 20a therethrough, same being arranged so as to overli-e the slots 2 la of nut 2|, and nut 2l and collar I9 are of approximately the same maximum diameter, which is substantially less than that of the barrel bore Illa.. Collar I9, disk 20 and nut 2| constitute the piston. The proportions of the parts are such that when the piston is drawn upwardly into bore Illa, the marginal portion of disk 20 will rub against the bore wall, with the result that the disk will be flex-ed downwardly against the upper conical surface of nut 2I, by which the disk will he supported in such position that its marginal portion will be held in contact with the bore wall. With the disk in this position, fluid may now freely from the portion of the bore lila above the disk 2li through the apertures or ports 20a and the slots 2Ia.. During such upward movement of the piston, the disk 20 and nut 2l, by virture of the bearing of the former upon lthe bore wall, form a centering guide for the lower end of the piston rod, guiding it in axial alignment with the aperture of the packing gland in which the piston rod slides.

Duringl the downward or inward stroke of the piston the flexible disk 20 is support-ed by the collar I9 in a position such that its outer portion is held in sealing contact with the bore wall, and in which position the ports 20a are closed against the lower face of the collar I9. This prevents passage of air into the bore above the piston during the time the latter is moving downwardly in said bore. As a result, ay partial vacuum is created in the bore above the piston. As the piston passes into the cavity lub, this vacuum is broken when the marginal portion of the disk passes the upper `end of the cavity.

The lower end of the barrel is fitted with a suitable pen section, as shown in Fig. l, including a feed bar 2li and pen point 25. The ink feed feed channel 24a for feeding ink to the pen point, and. which also serves as a channel for admission of ink into the barrel in the filling' operation.

In the construction illustrated in Figs. 1, 2 and 3, the sleeve 22 is provided adjacent its upper end with a transversely extending pin 2B, to act as a deiiector for the piston. This delector is arranged in such position that as the piston reaches the end of the downward or inward stroke, the beveled lower end of nut 2I will engage the deilector, and cam the lower end of the piston rod and the piston laterally, as to the position illustrated in Fig. 1. This movement is accommodated by a slight flexing of the piston rod. This lateral displacement of the piston increases the clearance between the margin of the disk 23 and the wall of the cavity IDD at one side of the piston. In the embodiment shown in Fig. l this increase of clearance occurs at the side of the piston corresponding to the under side of the feed bar and pen point, lbut it is obvious that the displacement oi the piston in any other radial direction relative to the feed bar may be likewise effected.

By virtue of this increased clearance between the margin of disk 20 and the wall of cavity Ib a liberal passage is provided for flo-w of ink from the ink reservoir to the pen section and the ink feed channel 24a of the feed bar and for passage of air bubbles in the opposite direction. Writing ink has more or less viscosity which causes it to bridgenar-row spaces under capillary attraction and interfere with the flow of the ink through such spaces. By virtue of the lateral displacement of the disk 20 as above described, the clearance between the margin of the disk 20 and the wall of cavity lob is increase-d to the point that the ink cannot lm across it and prevent ingress of the small air bubbles from the pen section to the ink reservoir.

As a consequence, when the pen is used in writing, an adequate supply of ink to the feed bar is maintained at all times, so long as there is ink in the reservoir.

The lateral displacement of the piston is illustrated in Fig. 3, in which the wall of the cavity lob is defined by the dotted line so marked, and the periphery of the disk 20 is defined by the dotted circle marked 2li. It will be noted that there is no distortion of the disk 2o when it is inthe laterally displaced position. Hence it is in no way disabled for the necessaryclose cooperation with the bore wall in an ensuing lling operation.

In the modified construction illustrated in Figs. 6 and 7, the d-electing member 28' is formed as a lug;l on the pen section sleeve, and 'cooperates with the nut ZI to displace the piston laterally as above described.

In the further modified construction illustrated in Figs. 4 and 5, the deiiecting member 28 is formed as a lateral extension of nut 2|, and cooperates with the upper portion of the pen section sleeve to effect the lateral displacement of the piston.

The piston rod is equipped at its upper end with a small capi 3i) having an external form and iinish appropriate for the barrel, said cap being molded onto, or otherwise affixed to, the nut I8. The lower threaded portion of this nut is adapted to screw into the threaded female portion at the upper end of the sleeve I4. The nut I8 is xedly secured to the piston rod. A suitable finish ferrule 3l is mounted on the upper end of the sleeve I4 to provide a seat for the skirt portion of the cap 30 and an appropriate finish for the joint between the cap and the upper end of the barrel.

An appropriate pen cap 32 is provided for housing the lower portion of the pen section when the pen is not in use.

In o-peration of the device to accomplish the filling of the pen, the pen cap 32 having been removed, the cap 30 is rotated to unscrew the nut I8 from the sleeve I4. The piston is then drawn upwardly in the barrel by traction on the cap 30. Incident to this operation, the disk 2D is flexed downwardly as seen in Fig. 2, and the ports Ella opened, so that ink and air in the bore lila. find free outlet therethrough, the marginal portion of the disk` being held in contact with the bore wall by the flange of nut 2l. After the piston has been thus drawn upwardly to the limit of its upward or outward stroke, it is pushed downwardly in the barrel by pressure on the cap 30. At the start of this downward Amovement of the piston, the disk 20 is iiexed into engagement with the collar I9, so that the ports 20a are closed and the marginal portion of the disk is maintained firmly in contact with the bore wall, as illustrated in Fig. 8, during the downward movement of the piston in the bore I ila. Before the piston reaches the lower end of the bore lila, the protruding portions of the pen point and feed bar and the lower extremity of the pen section sleeve 22 are immersed in a body of ink. Downward movement of the piston then being continued, disk 2@ enters cavity Ib and deflector 28 engages nut 2i and causes the piston to be displaced laterally. The bore cavity Ito. being thus placed in communication with the pen section, ink will be forced into the reservoir through ink channel 24a and past disk 2B. 'Ihen nut I8 is screwed home in sleeve I4, thus securing the piston in the position shown in Fig. 1.

The subjects matter of the pen section construction and the piston and piston rod construction illustrated and described but not claimed herein are claimed in my copending applications Serial Nos. 749,152 filed October 20, 1934, and 119,718, January 9, 1937.

What I claim is:

l. In a foimtain pen, in combination, a barrel having a bore constituting an ink reservoir and a cavity of greater diameter than the bore at the lower end thereof, a piston device for cooperation with the wall of the bore, a piston rod opierable to move said piston device longitudinally in the bore and into said cavity, and means in the barrel for cooperation with said piston rod to hold the piston device in a laterally displaced position in said cavity.

2. In a fountain pen, in combination, a barrel having a bore constituting an ink reservoir and a cavity having a portion of greater diameter than the bore at the lower end there-of, a piston device, a piston rod operable to move the piston device longitudinally in rubbing engagement with the wall of the bore and to positions within the longitudinal span of the cavity, and means adapted to cooperate with the piston rod for displacing the piston device laterally relative to a wall of the cavity incident to longitudinal movement of the piston device in the cavity.

3. In a fountain pen, in combination, a barrel having a bore constituting an ink reservoir,v a piston device movable longitudinally in the bore and adapted for fluid-tight cooperation with the wall thereof, said barrel having a cavity at the lower end of the bore to provide a passage for ow of ink past the piston, and means in the barrel below the piston device for cooperation with the piston rod to eiTect lateral displacement of the piston relative to said passage to increase the clearance between a wall thereof and the periphery of the piston.

4. In a fountain pen, in combination, a barrel having a bore for receiving ink, a piston movable longitudinally in rubbing contact with the bore wall, said barrel having an ink passage leading' from the lower end of the bore, a piston rod operable to move the piston longitudinally of the bore, and a deflector at the lower end of the barrel for holding the lower end of the piston rod in a laterally displaced position relative to said passage.

5. In a fountain pen, in combination, a barrel having a bore for receiving ink, a flexible piston movable longitudinally in rubbing contact with the bore wall, said barrel having an ink passage for flow of ink from the bore past the piston, and means in the barrel adapted for cooperation with the piston rod to increase the clearance between a portion of said passage and the piston.

6. In a fountain pen, in combination, a barrel having a bore for receiving ink, a piston rod movable longitudinally therein, a guide and packing for the piston rod mounted at the upper end of the barrel, a piston carried on the rod adjacent its lower end and adapted for sealing cooperation with the bore wall, the barrel aifording i an enlarged cavity at the lower end of the bore into which cavity the piston may be moved, and means in the barrel for cooperation with the piston rod to deflect its lower end laterally when the piston is in said cavity.

7. In a fountain pen, in combination, a barrel having a bore adapted to receive ink and a cavity at the lower end of the bore, a piston rod slidably mounted in the upper end of the barrel for movement longitudinally in the bore, a pen section sleeve mounted in the lower end of the barrel, a piston mounted on the piston rod adjacent its lower end and adapted for rubbing cooperation with the wall of the bore, and a delecting device mounted in the pen section sleeve for cooperation with the piston rod to displace its lower end and the piston laterally in said cavity.

8. In a fountain pen, in combination, a barrel having a bore adapted to receive ink and a cavity at the lower end of the bore, a piston rod slidably mounted in the upper end of the barrel, a piston mounted on the piston rod adjacent its lower end and adapted for rubbing cooperation with the wall of the bore, a retaining member mounted on the lower end of the rod for holding the piston thereon, and means disposed in the lower end of the barrel for engagement with said retaining member to hold the piston in laterally displaced position in said cavity.

ALBERT H. STENERSEN.

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