US2536924A - Writing instrument - Google Patents

Description

Jan. 2, 1951 H. R. FEHLING WRITING INSTRUMENT Filed June 4, 1946 Patented Jan. 2, 1951 WRITING INSTRUMENT Hans It. Fehling, London, England, assignor, by mesne assignments, to Eversharp, Inc., Chicago, Ill., a corporation of Delaware Application June 4, 1946, Serial No. 674,262 In Great Britain August 10, 1945 This invention relates to improvements in writing instruments, particularly to writing instruments of the type in which a ball is mounted for rotation in a housing with part of the ball exposed, said ball being supplied with ink or other marking uid from a suitable reservoir. The writing operation is such that, While the ball is rotated (as by being moved over and in contact with a writing surface, for example, a sheet of paper) it carries a supply of ink from the reservoir through the housing and depositsa trace of the ink on the writing surface.

In instruments of the aforesaid type 1t has been heretofore proposed to apply pressure to urge the lnk towards the ball. It has also been proposed to utilize a capillary tube for the ink reservoir in which case no mechanical pressure is applied. If the instrument is of the type in which pressure is applied, care must be exercised to yensure that the applied pressure does not cause seepage of ink past the ball when the instrument is not in use, since such seepage may spoil the users clothes or handbag and prove generally inconvenient; at the same time, the pressure must :be sufficient to overcome the resistance to ink flow when the instrument is being used.

Accordingly, the principal object of the present invention is to provide an improved writing instrument in which optimum results are obtained when the instrument is in use and in which the possibility of seepage is prevented when the instrrunent is not in use.

Viewed from one aspect the invention resides in an improved writing instrument of the ball point type having a removable cap, which functions, when the instrument is no-t in use, to pro- 'l Claims. (Cl. 1Z0-42.4)

tect the rotatable ball and, when the instrument is in use, functions to apply pressure to urge the ink towards the ball.

lFrom another aspect the invention resides in an improved writing instrument of the ball point type having a collapsible or pressure sensitive ink reservoir, a spring or other resilient member for applying pressure thereto, and a removable cover cap, which upon being fitted to the instrument (when the latter is to be used) compresses the spring to apply pressure to said reservoir, so that the lnk is urged towards the ball; said cap is preferably placed over the ball end of the instrument when the latter is not in use. Means, such as a sliding member with which isassociated a stop, are preferably provided for limiting the pressure that may be applied to the resilent member by the cap.

lFrom yet another aspect the invention resides in an improved writing instrument of the ball point type having a collapsible or pressure sensitive reservoir, a resilient member such as a spring,-

thread formed on the member in which the slid' ing member is housed.

In order that the nature of the invention may be more readily understood reference will now be made to the following detailed description in connection with the accompanying drawing in which:

Fig. 1 is a longitudinal sectional view, illustrating by way of example'one embodiment of this invention in which the disposition of parts is shown when the instrument is not in use, and

Fig. 2 is a sectional view of the rear part of the instrument when the latter is in use.

Referring now to the drawing, there is shown a writing instrument Ill of the ball point type having an outer barrel or casing I2 of suitable designv and size, at one end of which is housed a rotatable ball I4 with part of the Vball exposed. The ball I4 is preferably not less than,0.75 mm. and not more than 3 mm. in diameter; and the gap (not shown) between the ball I4 and its housing I 6 through which gap the ink is carried, as the ball rotates,

sensitive. It may, for example, be constituted by' a collapsible bag, or the-whole of the reservoir or the rear part thereof may be of light gauge corrugated metal; but in any event the reservoir or rear part thereof is of such a nature that, if pressure is applied thereto,it collapses or retracts to such anAextent that pressure is applied urging the ink within the container towards the ball.

In the construction shown,'the reservoir is in the form of a light gauge corrugated metal or rubber cylinder I8 housed within the casing I2. The overall diameter of that part 20 of the casing I2 extending rearwardly beyond the reservoir is preferably of reduced diameter, for reasons as will appear hereinafter. Within this part 20 is placed.

a coiled spring 22 interposed between a washer 24 at the rear end of the cylinder I3 and a washer 26 at the forward (inner) end of a push-button or plunger 28, which is mounted for sliding movement in the Open end of the reduced part 26. When the writing instrument I is not in use, this plunger 28 may extend beyond said open end as seen in Fig. 1. A stop or pin 30 projecting interiorly from the reduced part is provided for disposition within a slot 32 in the plunger 28 toV limit longitudinal movement of the plunger 2,8 both in and out of the part 20.

A removable cover cap illv is provided fory the. Writing instrument I6 which cap, when the4 in.. strument is not in use, is fitted over the ball endi thereof, as shown in Fig. 1; it may be a Dllhron 't or it may be screwed on to the casing; i2., as. shown.

Fitted within the closed end of cap 34 is a plug 36 having a centrally tapered recess 38 and on its outer peripheral surface a coarse thread 4Q.

When the -writing instrument IU is to be used, the cap 34 is removed from the ball end and is placed over the opposite end of the instrument. In this position the face of plug 36 engages and pushes the plunger 28 inwardly along the interior surface of reduced part 20, the outer end of this. part being formed with an interior thread 42 to receive the thread 4o on plug 3S. Consequently, as the plug 36 is screwed into the. open. end of: part 2B, spring 22 is compressed under the in- :tinence'of plunger 28 and this in turn collapses or [compresses the reservoir I3, thereby causing the, latter to urge the ink towards the ball I4. The thusly applied pressure during the use of the instrument is suiicient to facilitate the iiow of the ink from the. reservoir, equaling or slightly exceeding the capillary forces in the gap between the ball I4 and its housing I6 but is not suicient to result in objectionable seepage during normal writing activity. When use of the instrument is discontinued, the cap 34' is removed from the open end of the instrument, as shown in Fig. 2', and is replaced over the balll I4 in the position shown in Fig. 1. The plunger 2K8 is then retracted by spring 22 to its released position, as shown in Fig. l; with the result that the pressure on the ink' imposed' by the compression of the spring is either removed or materially reduced toa point Where it does not exceed the capillary force the gap between the ball I4 and its housing I6. It thus follows vthat eiective pressure for' writing purposes is Iapplied only while the instrument is in use, so that, when the instrument is not in use, risk of seepage is obviated'; furthermore. the cap 34 with plug 36 effectively protects and seals the ball I 4.

It will be readily seen that the reduced part 2D of the 'writing instrument I0 is substantially the same length as that of the cap 34. so that the cap 34 is `an easy t thereover (despite formation of the interior thread 42 therein) Aand that disposition of the cap over the rear end of the instrument is determined solely by the plug 36 cooperating with the open end of reduced part 26.

Ii' desired, the writing instrument Ill ma'v incorporate means for imparting to it lateral vand/or longitudinal resilience and in particular may incorporate one or `all of' the vfeatures set out in the specication of concurrent patent application Serial No. 674,261, filed June 4, 1946, in the names of Hans R. Fehling and Ernest A. Wicks.'

The ink with which the instrument is charged is-prefe'rably' a viscous ink andconveniently has a' viscosity of not less than 15 poise at 37 C;

4 While the aspects of this invention have been disclosed with reference to the specific embodiments shown, it is, of course, understood that various modifications may be made in the detailsv of construction without departing from the scope of this invention, as dened in the appended claims.

What is claimed is:

1. A writing instrument of the ball point type comprising, in combination, a resiliently deformable reservoir for supplying ink to said ball point, a, removable cap for protective disposition over saidy ball point while the instrument is not in use, said cap also-being adapted to be operatively connected to said reservoir While the instrument is being-` used, and means actuated -by and responsive tov said connection of the cap for deforming said reservoir to apply added pressure to the ink confined therein, whereby to assist iiow of the ink to said ball point while the instrument is in use.

2. A writing instrument comprising, in combination, a rotatable ball writing tip, a resiliently' deformable reservoir for supplying ink thereto, a removable cap adapted in one position for protective disposition over said ball writing tip while the instrument is not in use and in a second position to be operatively connected to said res-- ervoir while the instrument is in use, and meansincluding a plunger actuated by and responsive to said connection of the capv for deforming said' reservoir to apply pressure to the inkA conned therein, whereby to assist ow of the ink to said ball writing tip while the instrument is being used.

3. A writing instrument comprising, in combination, a casing having an open end of reduced diameter, a rotatable ball writing point at thev other end thereof, a reservoir of resilient materialv for supplying ink to said writing point disposed within said casing intermediate said ends, a pas-.- sage for interconnecting said writing point andsaid reservoir, a plunger adapted for limited reciprocal movement in the reduced end of said casing, resilient means interposed between said resilient reservoir and said plunger, and a removable cap adapted' to be secured to said re-V duced open end of said casing in abutting en-Av gagement with said plunger for moving the same and thereby compressing said resilient portion of said reservoir, whereby said ink is urged towards.. said writing point, said cap being disposed over' said writing point While the pen is not in use.

4. A writing instrument of the ball point type' comprising, in combination, a hollow barrel having an end portion of reduced diameter, a re-L l. sili'ent reservoir for supplying ink to said ball tion at one end and housing a writing tip at the y other end, a reservoir within said body for supplying ink to said writing point, passage meansinterconnecting said reservoir and said writing point, the end of said reservoir :farthest removed from the writing tip being of vresilient material `so that it'- is capable' of expanding'and collapsing.'v

a push button adapted for limited axial move `ment within the open end ofv the 'tubular body having an outer end extending normally beyond the body and having an inner face connected to said resilient portion of the reservoir, a removable cover cap for enclosing the writing tip of said fountain pen, said cover cap being adapted to be connected to said push button for moving the same and thereby urging said push button into an operative position with said reservoir when said pen is to be used, whereby said reservoir is adapted to urge ink to said writing point.

6. A fountain pen comprising, in combination, a tubular body having an axial perforation at one end and housing an ink reservoir and a Writing tip, the end of said reservoir farthest removed from the writing tip being of resilient material so that it is capable of expanding and collapsing, a push button adapted for limited axial movement within the end of the body farthest r'emoved from the writing tip having an outer end extending normally beyond the body and an inner end connected to said resilient portion of said reservoir, a removable cover cap for sealing the Writing tip of said fountain pen, said cover cap being adapted to be connected to said push button for moving the same and thereby compressing said reservoir when said pen is to be used, whereby ink is urged to said Writing tip, and means on said cover cap and body for locking said push button in operative position While the fountain pen is being used.

7. A fountain pen comprising, in combination, a tubular body having an axial perforation at one end and housing an ink reservoir and a writing tip, passage means interconnecting said reservoir and Writing tip, the end of said reservoir farthest removed from the writing tip being of resilient material so that it is capable of expanding and being compressed, a slidable plunger adapted for limited axial movement within the end of the body farthest removed from the writing tip, spring means interposed between said reservoir and said plunger, a removable cover cap for sealing the writing tip of said fountain pen, said cover cap being adapted to be connected to said plunger for moving the same and thereby compressing said spring means and reservoir when said pen is to be used, whereby ink is urged to said writing tip, and threaded means on said cover cap and said tubular body for locking said plunger in operative position while the fountain pen is being used.

HANS R. FEHLING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 448,939 Cronkheit Mar. 24, 1891 799,297 Betzler Sept. 12, 1905 1,712,141 Folk May 7, 1929 1,980,625 Laforest Nov. 13, 1934 2,276,722 Hillman Mar. 17, 1942 2,362,321 Steven Nov. 7, 1944 2,400,679 Biro May 21, 1946 2,409,847 Gregg Oct. 22, 1946 2,432,061 Chesler Dec. 2, 1947

Images