US2142531A - Fountain pen - Google Patents

Description

Patented Jan. 3, 1939 FOUNTAIN PEN Albert H. Stenen-sen, Chicago, lll., assignor to The Wahl Company, Chicago, IIL, a corporation of Delaware Application January 9, 1937,'Serial- No. 119,718

15 Claims. (Cl. 120-47) f This invention relates to fountain pens and v pertains particularly to self-filling fountain pens of the piston type, i. e., the type having a piston operable in the pen barrel to effect the lling of the ink reservoir. The present application is a continuation in part of my copending application Serial No. 24,663, filed June 3, 1935.

One of the objects of` the invention is the provision of an improved construction for the piston of a fountain pen of the sort above referred to which will have the necessary strength and desired durability and in which all metal portions are effectively protected against oxidation or deterioration under the action of the ink.

Another object is the provision of an improved construction for a fountain pen of the piston type which will reduce the possibility of leakage of ink through the packing gland in which the piston rod operates.

Another object is the provision of an improved construction for a fountain pen of the sort specified which will render the operation of the piston for 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 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, A

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

Fig. 2 is a part longitudinal section of the same but showing certain of the parts in positions which they assume in the upward movement of the piston; f

Fig. 3 is a part longitudinal section' of the upper end portion of the pen barrel showing positions assumed by parts of the piston at the end'of its upward stroke; y

Fig. 4 is a part longitudinal section showing positions occupied by parts of the piston during its downward stroke;

Fig. 5 is a perspective view of a nut and abutment member constituting a portion of the piston illustrated in the other gures; and

Fig. 6 is a face view of a flexible disk or washer which constitutes a portion 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 pres- 'sure behindv the piston on its downward stroke,

the evacuated portion of the barrel being placedl in communication with the pen 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 section and into the reservoir above the piston.

Pens of this type heretofore employed have shown tendencies to leak through the packing gland in which the pistonrod operates at the upper end of the barrel, such tendencies being increased by the necessity for forcing ink past the periphery of the piston in the course of the movement of the latter to its upper position in the barrel preliminary to the downward or evacuating stroke of the piston. One of the objects of the present invention is to remove causes which promote such leakage.

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 barrelv I which affords a bore or internal cavity Illa of uniform crosssectional size and contour, which `cavity constitutes an ink reservoir. At its lower terminus it merges into a cavity IIlb of greater crosssectional size such as to afford a clearance space for the piston as hereinafter described.

In the upper end of the barrel is fixed a bushing Il which supports a washer I2, and also in the upper end of the barrel is secured a sleeve I 4 having a cavity which houses a plurality of layers I of packing ,materiaL all or some of which may be flexible and compressible. 'I'his packing is compressed against the washer I2 by the screwing down of the sleeve I4. The bushing Il, washer I2, sleeve Il and packing material I 5 are provided with axial apertures which align to afford a passage for the piston rod I6.

The piston rod, as seen more particularly in Fig. 2, comprises a core Ilia of'metal wire and a sheath I6b of hard rubber vulcanized thereon. The upper end portion of the core extends beyond wall of the barrel bore.

the sheath and has a lamb nut Il and a stepped nut I l threaded thereon. A short distance from its lower en`d the sheath is formed with a peripherally projecting shoulder Isc. Fitted on the lower end portion oi' the sheath is a rigid collar I9, of hard rubber, which is counterbored to accommodate and abut the shoulder lic. Centered on the portion lid of the sheath below this collar I9 is a disk 20 of ilexible rubber, said disk being of substantially greater diameter than the diameter of the barrel bore Illa and of somewhat lesser diameter than the diameter of the cavity Ib. This disk is provided with a plurality of port openings 20a and a central aperture 20h, the latter being somewhat smaller in diameter than the portion ISd of the sheath on which the disk is retained. Hence', in order to mount the disk on the sheath portion ISd, the central portion has to be stretched somewhat, which causes it to assume a slightly dished form as illustrated in Fig. 1. The lower end of the core Isa` projects beyond the lower end of the sheath and has screw-threaded thereon a hard rubber spider nut 2I, the upper face of which is frusto-conical in form and provided with a plurality of longitudinally extending slots 2Ia. Nut 2I is set up tightly against the lower end of the sheath ISb below disk 2li.

It will be observed that by virtue of this construction all portions of the metal core I6a which enter the barrel are completely enshrouded in rubber, thus preventing access of ink to the metal. l

The port apertures 20a of xible disk 20 are `of such size and arrangement that one or more of them will overlie or partly overlie one or more of the slots 2Ia of nut 2l. Nut 2| and collar I9 are of approximately the same maximum diameter, which-is substantially less than that of the barrel bore Ia. Collar I9, disk 20 and nut 2I constitute the piston. 'I'he form and proportions of the parts are such that when the piston is drawn upwardly in bore Ina, the marginal portion of disk 20 -will rub against the bore wall of the barrel, with the result that the disk will be ilexed downwardly against the upper conical surface of nut 2l, and the disk will be supported by the ilange oi' the nut in such position that the marginal portion of the disk will be held definitely in rubbing contact with the bore wall as illustrated in Fig. 2. With the disk in this position, uid may ilow freely from the portion of the 'bore Illa above the disk 20 through the apertures or ports 20a and the slots 2Ia. Consequently, as the piston is moved upwardly in the barrel, no material amount of pressure can be built up on air or such ink as may be in the barrel above the piston. `Accordingly, there will be no pressure in the barrel effective to cause leakage through the packing gland. During such upward movement of the piston, the disk 20 and nut 2I, by virtue of the bearing of the i'ormer upon the 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, and maintaining the disk 20, about its entire circumference, in close contact with the As shown in Figs. 1 and 3, the barrel is provided with a shallow internal circumferential groove IIIc located at a suitable distance below the bushing I I to receive the marginal portion of the disk 20 when the piston is in its upper limit position. This is for the purpose 0f momentarily retaining the marginal Purton 0f the disk 2l at the start of the downward movement of the piston, to insure the disk being positively ilexed upwardly against the collar I9.

During the downward or inward stroke of the piston the ilexible disk 2II is supported by the collar Il in a position such that its outer portion is held in sealing contact with the bore wall, as illustrated in Fig. 4, and in which position the ports 20a are closed against the lower face of the collar I9. This prevents passage oi' air into the bore above the piston during the time the latter is moving downwardly in said bore. As a result, a partial vacuum is created in the bore above the piston. As the piston passes into the cavity Ib. this vacuum is broken when the marginal portion of the disk passes the upper end of the cavity.

The lower end of the barrelis tted with a suitable pen section, as shown in Fig. 1, which includes a pen section sleeve 22 screw threaded in the lower end of the barrel, and an ink feed bar 2l and pen point 25 which are mounted in the lower portion of said sleeve. 'I'he ink feed bar has the conventional ink feed channel 24a for feeding ink to the pen point, and which also serves as a channel i'or admission of ink into the barrel in the lling operation.

In the construction illustrated in Figs. 1 and 2 the sleeve 22 may be provided adjacent its upper end with a transversely extending pin 28, to act as a deector for the piston. This deector 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 piston laterally, as to the position illustrated in Fig. l. This movement is accommodated by a slight ilexing of the piston rod. 'I'his lateral displacement of the piston increases the clearance between the margin or the disk 2l and the wall of the cavity IIIb at one side of the piston.

The piston rod is equipped at its upper end with .a small cap III having an external form and finish appropriate for the barrel, said cap being moldedr onto, or otherwise amxed 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 Il. 'I'he nut I8 is xedly secured .to the piston rod. A suitable ilnish ferrule II is mounted on the upper end of the sleeve Il to provide a seat for the skirt portion of the cap 30 and an appropriate nish for the joint between the cap and the upper end of the barrel.

In operation of the device to accomplish the filling of the pen, the cap III is rotated to unscrew the nut I8 from the sleeve I4. 'I'he piston is then drawn upwardly in the barrel by traction on the cap 30. Incident to this operation, the disk 20 is flexed downwardly as seen in Fig. 2, and the ports 20a opened, so that ink and air in the bore Ia ilnd iree outlet therethrough, the marginal portion of the disk being held in contact with the bore wall by the ilange of nut 2l. When the piston has been thus drawn upwardly to the limit of its upward or outward stroke, the margin of the disk 2li springs into the shallow groove IlIc, where it is retained until it is pushed downwardly in the barrel by pressure on the cap 3U. At the start of this downward movement of the piston, the disk 2Il is flexed into engagement with the collar I9, so that the ports 20a are closed and the marginal portion of the disk is maintained rlrmly in contact with the bore wall, as illustrated in Fig. 4, during the downward movement of the piston in the bore I0a. Before the piston reaches the lower end of the bore Ita, the

y amaca:

protruding portions of the pen point and feed...

sleeve i4, thus securing the piston in the positionV shown in Fig. l. What I claim is:

1. In a fountain pen filling device, a piston rod having a metal core with a sheath of ink-resistant material, said sheath having an outwardly projecting shoulder, a collar encircling the sheath and abutting said shoulder, a nut threaded on the core and abutting the end of the sheath,

and a piston disk encircling the sheath and re- 20 tained thereon between the collar and nut.

2. In a fountain pen filling device, a piston rod having a metal core with a sheath of ink-resistant material, a collar on the sheath, a nut of inkresistant material retentively engaged with the core and abutting the end of the sheath, and a piston disk retained on the sheath between the collar and nut.

3. In a fountain pen having a barrel with a cylindrical bore, a filling device comprising a piston rod reciprocable longitudinally in the bore,

a flexible piston disk carried on the rod and of greater diameter than the bore, said disk being provided with a port therethrough located eccentrically thereof, a collar on the rod for abutment with one side of the disk to close said port, and a stop member on the rod` at the other side of the disk for cooperation therewith to limit its exure away from the collar but hold its marginalportion in contact with the bore wall of the barrel.

4. In a fountain pen lling device, a construction asA specified in claim 3 and wherein the stop member is provided with a passage arranged to communicate with the port of the disk when the latter is ,against the stop member.

5.' A fountain pen with filling device as specified in claim 3 and wherein the barrel bore is circumferentially enlarged adjacent each of its ends to accommodate the peripheral portion of the exible piston disk for the purpose described.

6. A fountain pen with filling device as speciiied in claim 3 and wherein the barrel is provided adjacent each end of its bore with a portion for restraining engagement with the peripheral portion of the flexible piston disk, for the purpose described.

7. In a fountain pen, in combination, a barrel having a bore for receiving ink and an ink passage communicating with the lower end of said bore, a piston rod movable longitudinallyin the bore, a flexible disk carried by the piston rod and having a diameter greater than the bore, said disk being provided with an aperture therethrough constituting a port for passage of fluid, a collar carried on the rod above the disk and adapted to support the marginal portion of the latter in rubbing contact with the bore wail during movement of the piston downwardly in the bore and having a portion for cooperation with the disk to close the port against passage of fluid during such downward movement of the piston, and an abutment member carried on the rod below the disk and adapted to support the marginal portion thereof in rubbing contact with the bore wall during upward movement of the piston in the bore. said abutment member being formed toaccommodate flexure of the disk downwardly away from the collar to open the port to flow of fluid therethrough during such upward movement of the piston.

8. A fountain pen construction as specified in i claim 7 and wherein said abutment member is provided with an ink flow passage arranged for` communication with-the port when the port is spaced away fromthe collar.

9. A fountain pen construction as specified in claim 7 and wherein said ink passage of the barrel is of size and form such as to permit the d isk to assume a position normal to the rod after the gsk has been moved beyond the lower end of the 10.'In a fountain pen having a barrel formed with an ink-receiving bore, a piston adaptedfor movement longitudinallyin the bore, said piston including a rod, a flexible elastic disk mounted on'said rod, saiddisk being of greater diameter than the barrel bore and being providedwith an` aperture therethrough aiiording a port for passage of uid, a collar on the rod above` the disk and adapted to support the marginal portion thereof in rubbing contact with the bore wall and fied in claim 10 and wherein the bore wall of the` barrel is provided with a shallow circumferentially extending groove in position to receive the marginal portion of the disk when the piston is in its upper limit position.

12. In a fountain pen, a construction as specified in claim 10'and including also means for restraining the'marginal portion of the disk at the beginning .of the downward movement of the piston' from its upper limit position.

13. In a fountain pen, a construction as specified in claim 10 and wherein the exible piston disk is of elastic material and centrally apertured to receive the rod and its `central portion around the aperture is held somewhat expanded radially by the rod portion on which it is mounted, so that the disk assumes a slightly dished form.

14,. In a fountain pen having a barrel `with a cylindrical bore and an enlarged cavity at the lower end of the bore, a filling device comprising` a piston rod reciprocable longitudinally in the bore, a collar fixed on the rod adjacent its lower end, a radially slotted nut on the rod below the collar, and a flexible piston disk of larger diameter than the barrel bore retained on the rod between the collar and nut and bearing at its margin on the bore wall, said piston disk being apertured to form a port and being flexible upwardly into abutment with the collar to close the port and downwardly into abutment with the nut to open the port and place it in communication with the slot of the nut, said piston disk being movable into the enlarged cavity of the barrel near the end of the downward movement of the piston rod. y

15. In a fountain pen having a barrel with a cylindrical bore and an enlarged cavity at the lower end of the bore, a filling device comprising a piston rod reciprocable longitudinally in the bore, an over-size flexible elasticpiston disk carned on the rod adjacent 1u' lower ena, ma putondlsk bein's apertured toaii'ord aport theref through, and a collar i'ixed on the rod above the piston disk in position for engagement by the disk i to close said port and support the marginal portion o! the disk in rubbing engagement with tho ALBERT n.

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