Pen

Abstract

A ballpoint pen using liquid ink including a pen housing, an ink cartridge, and ball-carrying plunger assembly reciprocably movable in the housing so that the ball and assembly may be moved forwardly to protrude from the housing, a disc of rubberlike material having a central perforation therethrough and located internally and at the forward end of the housing through which the ball and assembly may be moved and forming an ink seal when the ball and assembly is in retracted position in the housing, and selectively operable means at the other end of the housing for selectively moving the cartridge and ball assembly forwardly in the housing and holding it in such a position.

Description

My invention relates to writing instruments and more particularly to pens using liquid ink.

It is an object of the invention to provide an improved pen with a ballpoint that uses a liquid ink; and still more particularly, it is an object of the invention to provide an improved pen of the type disclosed in my U.S. Pat. No. 3,360,329 , which is so arranged that the ballpoint may be selectively moved forwardly of the pen housing so that it protrudes from the housing in writing position and may be selectively withdrawn into the housing under spring action when the pen is not in use, with means being provided for sealing the forward end of the housing so that ink may not leak through the forward end of the housing when the pen is not in use .

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed, for carrying out the above-stated objects, and such other objects, as will be apparent from the following description of preferred embodiments of the invention, illustrated with reference to the accompanying drawings, wherein:

FIG. 1 is a longitudinal sectional view of a pen embodying the principles of the invention;

FIGS. 2 and 3 are plan views on an enlarged scale of two rubber valve elements incorporated in the pen and taken respectively on lines 2-2 and 3-3 of FIG. 1;

FIG. 4 is a partial longitudinal sectional view of the pen; and

FIG. 5 is a partial longitudinal sectional view of a modified internal part of the pen.

Like characters of reference designate like parts in the several views.

The pen disclosed herein is of a type generally similar to that disclosed in my prior patents, U.S. Pat. No. 3,360,329, issued Dec. 26, 1967, and certain parts that generally correspond to parts in the pen shown in my U.S. Pat. No. 3,360,329 will be indicated by the same reference numerals except with the subscript a attached thereto.

The principal difference between the pen described in my prior U.S. Pat. No. 3,360,329 and that disclosed herein, lies in the fact that the pen disclosed herein is arranged to propel and retract its ballpoint nib selectively outwardly and inwardly with respect to the housing of the pen. The pen illustrated herein and that disclosed in my prior U.S. Pat. No. 3,360,329, operate generally in the same manner, namely in causing ink to flow through the pen and onto the ball due to writing pressure being applied onto the external barrel of the pen by the user in using the pen.

Referring now to the drawings, the illustrated pen may be seen to comprise outer housing or barrel portions 100 and 101. The portion 100 and 101 are provided with threaded portion 103 that mate and allow the portion 101 to be screwed downwardly onto the portion 100. The housing portions 100 and 101 provide a cylindrical cavity 11a within them for the internal parts of the pen. A cylindrical cartridge 21a containing liquid ink is disposed in the cavity 11a, and the cartridge rests on a plunger 14a also slidably disposed in the cavity 11a.

The plunger 14a is provided with longitudinal drillings 104 and 105 therein which respectively extend slightly upwardly and downwardly from the ends of the plunger 14a as the plunger is viewed in FIG. 1, and a slot 33a extends transversely through the plunger 14a and is in communication with the drillings 104 and 105 as shown in FIG. 1. A tube 27a is press fitted into a longitudinally extending counterbore in the drilling 104 and is tapered to decrease in diameter outwardly of the drilling 104 as shown. The tube 27a is provided with a biased or slanted end 32a so as to, in effect, sharpen the tube 27a on one side, so that the tube 27a may easily perforate the forward end of the cartridge 21a.

Two rectangular rubber valve elements 34a and 35a are disposed in the slot 33a. The rubber element 34a is provided with a valve flap 37a cut into it and is also provided with an opening 38a through it. The rubber element 35a has a similar valve flap 39a in it and has an opening 40a through it. A separator 36a of rigid material, such as metal, is provided between the rubber elements 34a and 35a and is provided with two openings 41a and 42a through it. The opening 41a is in registration with the opening 38a, and the opening 42a is in registration with the opening 40a and is also in registration with an opening 43a in the plunger 14a which terminates on the outer peripheral surface of the plunger 14a.

The valve elements 34a and 35a are preferably held in compression between sides of the slot 33a so as to seal them with respect to the sides and ends of the slot and with respect to the separator 36a. In this connection, the separator 36a preferably has sharpened edges 106 so that the rubber elements 34a and 35a make a better seal with respect to the ends of the slot 33a. The rubber elements 34a and 35a may be put into this disposition in the slot 33a by elongating them under tension as they and the separator 36a are moved into the slot 33a so that, when the tension on the rubber elements 34a and 35a is released, the elements 34a and 35a contract and thus increase in thickness to effectively seal themselves and also the separator 36a within the slot 33a.

A bushing 17a is press fitted into a longitudinally extending counterbore in the drilling 105, and a tube 18a is press fitted into the bushing 17a and has a ball 19a rotatably disposed in a socket provided in the end of the tube 18a.

The plunger 14a is provided with a plurality of ink receiving, longitudinally extending channels 107 adjacent the ball 19a on the tapered forward end portion 108 of the plunger 14a. The housing portion 100 is provided with an internal peripheral groove 109, and a disc 110 of rubber like material is positioned in the groove 109 and is fixed at its edges therein as with cement. The disc 110 has a perforation 111 through it which may, for example, be formed by a pin being passed through the center of the disc 110 without cutting away an portion of the disc 110 so that when the disc 110 is in relaxed or flat condition, as shown in FIG. 1, it forms a nonleak seal through which liquid ink may not penetrate.

A shoulder 112 is formed on the exterior surface of the plunger 14a, and an internal shoulder 113 is provided in the housing portion 100; and a compression spring 114 is disposed between the shoulders 112 and 113.

A plunger 115 is provided within the cavity 11a at the upper end of the cavity. The plunger is formed with a peripheral channel 116, a relatively large diameter peripheral portion 117 of nearly the same diameter as the cavity 11a and a longitudinally extending rounded central tip portion 118 which rests on the center portion of the upper end of the cartridge 21a. The housing portion 101 is provided with an inwardly extending shoulder 119 surrounding the plunger 115 which is just slightly less in thickness than the longitudinal length of the channel 116.

In operation, the plunger 115 is moved downwardly into the pen barrel made up of the portions 100 and 101 so as to move the cartridge 21a and the plunger 14a downwardly in the pen barrel. The ball 19a and the tapered forward end portion 108 of the plunger 14a pass through the opening 111 in the disc 110 and distend the disc so that the distended disc lies over the forward end portion 108. The forward end portion 108 of the plunger 14a and the ball 19a thus extend from the pen barrel formed by the portions 100 and 101 as shown dotted in FIG. 1 so that the ball 19a is now in writing position. The plunger 115 under these conditions is swung outwardly so that the shoulder 119 enters the channel 116, and the plunger 115 may be released while still holding the cartridge 21a and plunger 14a in forward position. This movement of the cartridge 21a and plunger 14a is, of course, against the action of the spring 114 extending between the shoulders 112 and 113.

When writing, the user simply applies a writing pressure on the outer pen housing, particularly on the barrel portion 100, and this has the effect of transmitting a force through the plunger 115 and the rounded plunger end portion 118 on the upper end of the cartridge 21a so as to provide an air pressure within the cartridge 21a. The upper end 23a of the cartridge 21a is a round, thin, substantially uniform thickness piece of slightly yieldable material, such as polyethylene, and it thus functions as a type of piston for this purpose, bending downwardly at its center when force from the tip portion 118 is applied thereto as the user puts downward writing force on the pen. The valve flaps 37a and 39a respectively yieldably closing the openings 42a and 41a each functions as a one-way valve for respectively venting air into the drilling 104 and for allowing ink to flow from drilling 104 to drilling 105 but not in the opposite direction. Ink, therefore, flows through the drilling 104 and the openings 38a and 41a, around the flap 39a, and through the drilling 105, the bushing 17a and tube 18a to the ball 19a, this operation being similar to that described for the pen in my prior patent, U.S. Pat. No. 3,360,329. Air is admitted into the drilling 104 to make up for the ink that is so transmitted to the ball 19a through the openings 43a, 40a and 42a and around the valve flap 37a.

In order to cause retraction of the plunger 14a and ball 19a back into the pen housing formed by the portions 100 and 101, the plunger 115 is simply swung to central position so as to release the shoulder 119 from the channel 116, and the spring 114 moves the plunger 14a and the cartridge 21a back into their positions as illustrated in full lines in FIG. 1. The opening 111 then again closes the disc 110 to form a fluid seal so that any ink that may drop from the ball 19a will not flow through the forward end of the housing portion 100. Thus, the pen may be placed in a person's pocket with the forward end of the housing portion 100 being in the pocket without any ink leaking into the person's pocket. It will be understood that any appropriate clip may be used in connection with the illustrated pen for the purpose of holding the pen in an upright position in the user's pocket.

The longitudinally extending channels 107 in the tapered end portion 108 of the plunger 14a are provided for the purpose of collecting any surplus ink flowing from the ball 19a for subsequent drying in the channels 107. In lieu of the longitudinal channels 107, the circular peripheral channels 120 shown in the plunger 14a in the FIG. 5 modification may be provided, and the disc 110 in wiping along the tapered forward portion 108 has the action of wiping surplus ink into the channels 120 in which the ink subsequently dries.

In replacing the cartridge 21a in the pen after exhaustion of the liquid ink thereon, the housing portion 101 may be unscrewed from the housing portion 100, and the cartridge 21a may be pulled away from the plunger 14a. The new cartridge 21a may then be inserted in position against the sharpened end of the tube 32a. Then, with the shoulder 119 within the channel 116, the housing portion 101 may be screwed onto the portion 100 to bring it into its FIG. 1 position with respect to the housing portion 100; and, during this movement, with the rounded end portion 118 of the plunger 115 bearing on the upper end of the new cartridge 21a, the lower end of the cartridge 21a is penetrated by the tube 27a so as to bring the cartridge into the position as shown in FIG. 1. The housing portion 100 has an inwardly extending shoulder part 121 adjacent the groove 109; and, under these conditions, the shoulder part 121 limits the downward movement of the plunger 14a within the housing portion 100.

I wish it to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention. More particularly, I wish it to be understood that although the plunger 115 is provided for moving the cartridge 21a and plunger 14a forwardly in the pen against the action of the spring 114, any other suitable conventional mechanism for moving these parts forwardly and holding them in forward position may be used instead of the plunger 115.

Claims

I claim:

1. A pen comprising an elongate casing, a fluent ink cartridge assembly movable disposed within said casing and having a forward end portion extending from a forward end of said casing and providing a writing point, said cartridge assembly having a rear end portion within said casing in the form of a yieldable resiliently restrained piston, force-applying means carried by said casing acting on said piston for thereby moving said piston forwardly when writing force is put on said writing point so as to put pressure on the fluent ink to move the ink to said writing point, and a spring in said casing and effectively between said cartridge assembly and said casing for holding said piston against said force-applying means with the force of said spring.

2. A pen as set forth in claim 1, said writing point including a ball rotatably disposed in the forward end of said cartridge assembly.

3. A pen as set forth in claim 1, said cartridge assembly being cylindrical at its rear end and said piston constituting the round rear end of said cartridge assembly and being of yieldable material so as to be yieldable and resiliently restrained as aforesaid.

4. A pen as set forth in claim 2, said force-applying means being in the form of a plunger and having means for locking the plunger with respect to said casing in a forward position so as to hold said forward end portion of said cartridge assembly protruding from said casing and releasable to allow said spring to move said cartridge assembly and said ball into said casing.

5. A pen as set forth in claim 4, said cartridge assembly on its forward end rearwardly of said ball being provided with a series of external grooves, said ink being liquid and said casing including a resilient washer through which said ball and forward end of said assembly are moved when said plunger is operative to move said assembly forwardly in said casing so that excess liquid ink is wiped by said washer into said grooves.